HZB Newsroom

  • Stability of perovskite solar cells reaches next milestone
    Science Highlight
    27.01.2023
    Stability of perovskite solar cells reaches next milestone
    Perovskite semiconductors promise highly efficient and low-cost solar cells. However, the semi-organic material is very sensitive to temperature differences, which can quickly lead to fatigue damage in normal outdoor use. Adding a dipolar polymer compound to the precursor perovskite solution helps to counteract this. This has now been shown in a study published in the journal Science by an international team led by Antonio Abate, HZB. The solar cells produced in this way achieve efficiencies of well above 24 %, which hardly drop under rapid temperature fluctuations between -60 and +80 Celsius over one hundred cycles. That corresponds to about one year of outdoor use.
  • Scientists Develop New Technique to Image Fluctuations in Materials
    Science Highlight
    18.01.2023
    Scientists Develop New Technique to Image Fluctuations in Materials
    A team of scientists, led by researchers from the Max Born Institute in Berlin and Helmholtz-Zentrum Berlin in Germany and from Brookhaven National Laboratory and the Massachusetts Institute of Technology in the United States has developed a revolutionary new method for capturing high-resolution images of fluctuations in materials at the nanoscale using powerful X-ray sources. The technique, which they call Coherent Correlation Imaging (CCI), allows for the creation of sharp, detailed movies without damaging the sample by excessive radiation. By using an algorithm to detect patterns in underexposed images, CCI opens paths to previously inaccessible information. The team demonstrated CCI on samples made of thin magnetic layers, and their results have been published in Nature.
  • High-energy X-rays leave a trace of destruction in bone collagen
    Science Highlight
    22.12.2022
    High-energy X-rays leave a trace of destruction in bone collagen
    A team of medical researchers at Charité has analyzed damage by focused high energetic X-rays in bone samples from fish and mammals at BESSY II. With a combination of microscopy techniques, the scientists could document the destruction of collagen fibres induced by electrons emitted from the mineral crystals. X-ray methods might impact bone samples when measured for a long time they conclude.
  • Neutron experiments reveal what maintains bones in good function
    Science Highlight
    21.12.2022
    Neutron experiments reveal what maintains bones in good function
    What keeps bones able to remodel themselves and stay healthy? A team from Charité Berlin has discovered clues to the key function of non-collagen protein compounds and how they help bone cells react to external load. The scientists used fish models to examine bone samples with and without bone cells to elucidate differences in microstructures and the incorporation of water. Using 3D neutron tomography at the Berlin research reactor BER II, they succeeded for the first time in precisely measuring the water diffusion across bone material - with a surprising result.
  • New software based on Artificial Intelligence helps to interpret complex data
    Science Highlight
    20.12.2022
    New software based on Artificial Intelligence helps to interpret complex data
    Experimental data is often not only highly dimensional, but also noisy and full of artefacts. This makes it difficult to interpret the data. Now a team at HZB has designed software that uses self-learning neural networks to compress the data in a smart way and reconstruct a low-noise version in the next step. This enables to recognise correlations that would otherwise not be discernible. The software has now been successfully used in photon diagnostics at the FLASH free electron laser at DESY. But it is suitable for very different applications in science.
  • 4000th protein structure decoded at BESSY II
    Science Highlight
    13.12.2022
    4000th protein structure decoded at BESSY II
    The 4000th structure is the molecule FKBP51, which is linked to stress-induced diseases such as depression, chronic pain and diabetes. The team led by Prof. Felix Hausch, TU Darmstadt, is using the knowledge of the three-dimensional structure to develop new strategies for the design of suitable drugs.
  • Nanodiamonds can be activated as photocatalysts with sunlight
    Science Highlight
    30.11.2022
    Nanodiamonds can be activated as photocatalysts with sunlight
    Nanodiamond materials have potential as low-cost photocatalysts. But until now, such carbon nanoparticles required high-energy UV light to become active. The DIACAT consortium has therefore produced and analysed variations of nanodiamond materials. The work shows: If the surface of the nanoparticles is occupied by sufficient hydrogen atoms, even the weaker energy of blue sunlight is sufficient for excitation. Future photocatalysts based on nanodiamonds might be able to convert CO2 or N2 into hydrocarbons or ammonia with sunlight.
  • New monochromator optics for tender X-rays
    Science Highlight
    30.11.2022
    New monochromator optics for tender X-rays
    Until now, it has been extremely tedious to perform measurements with high sensitivity and high spatial resolution using X-ray light in the tender energy range of 1.5 - 5.0 keV. Yet this X-ray light is ideal for investigating energy materials such as batteries or catalysts, but also biological systems. A team from HZB has now solved this problem: The newly developed monochromator optics increase the photon flux in the tender energy range by a factor of 100 and thus enable highly precise measurements of nanostructured systems. The method was successfully tested for the first time on catalytically active nanoparticles and microchips.
  • Tomography shows high potential of copper sulphide solid-state batteries
    Science Highlight
    28.11.2022
    Tomography shows high potential of copper sulphide solid-state batteries
    Solid-state batteries enable even higher energy densities than lithium-ion batteries with high safety. A team led by Prof. Philipp Adelhelm and Dr. Ingo Manke succeeded in observing a solid-state battery during charging and discharging and creating high-resolution 3D images. This showed that cracking can be effectively reduced through higher pressure.

  • Quantum algorithms save time in the calculation of electron dynamics
    Science Highlight
    22.11.2022
    Quantum algorithms save time in the calculation of electron dynamics
    Quantum computers promise significantly shorter computing times for complex problems. But there are still only a few quantum computers worldwide with a limited number of so-called qubits. However, quantum computer algorithms can already run on conventional servers that simulate a quantum computer. A team at HZB has succeeded to calculate the electron orbitals and their dynamic development on the example of a small molecule after a laser pulse excitation. In principle, the method is also suitable for investigating larger molecules that cannot be calculated using conventional methods.
  • How photoelectrodes change in contact with water
    Science Highlight
    17.11.2022
    How photoelectrodes change in contact with water
    Photoelectrodes based on BiVO4 are considered top candidates for solar hydrogen production. But what exactly happens when they come into contact with water molecules? A study in the Journal of the American Chemical Society has now partially answered this crucial question:  Excess electrons from dopants or defects aid the dissociation of water which in turn stabilizes so-called polarons at the surface. This is shown by data from experiments conducted at the Advanced Light Source at Lawrence Berkeley National Laboratory. These insights might foster a knowledge-based design of better photoanodes for green hydrogen production.
  • BESSY II: Influence of protons on water molecules
    Science Highlight
    10.11.2022
    BESSY II: Influence of protons on water molecules
    How hydrogen ions or protons interact with their aqueous environment has great practical relevance, whether in fuel cell technology or in the life sciences. Now, a large international consortium at the X-ray source BESSY II has investigated this question experimentally in detail and discovered new phenomena. For example, the presence of a proton changes the electronic structure of the three innermost water molecules, but also has an effect via a long-range field on a hydrate shell of five other water molecules.
  • Photocatalysis: Processes in charge separation recorded experimentally
    Science Highlight
    08.11.2022
    Photocatalysis: Processes in charge separation recorded experimentally
    Certain metal oxides are considered good candidates for photocatalysts to produce green hydrogen with sunlight. A Chinese team has now published exciting results on copper(I) oxide particles in Nature, to which a method developed at HZB contributed significantly. Transient surface photovoltage spectroscopy showed that positive charge carriers on surfaces are trapped by defects in the course of microseconds. The results provide clues to increase the efficiency of photocatalysts.

  • Batteries without critical raw materials
    Science Highlight
    26.10.2022
    Batteries without critical raw materials
    The market for rechargeable batteries is growing rapidly, but the necessary raw materials are limited. Sodium-ion batteries, for example, could offer an alternative. A joint research group from HZB and Humboldt-Universität zu Berlin has investigated new combinations of electrolyte solutions and electrode materials for this purpose.
  • Tandem solar cells with perovskite: nanostructures help in many ways
    Science Highlight
    24.10.2022
    Tandem solar cells with perovskite: nanostructures help in many ways
    By the end of 2021, teams at HZB had presented perovskite silicon tandem solar cells with an efficiency close to 30 percent. This value was a world record for eight months, a long time for this hotly contested field of research. In the renowned journal Nature Nanotechnology, the scientists describe how they achieved this record value with nanooptical structuring and reflective coatings.
  • Spintronics: A new tool at BESSY II for chirality investigations
    Science Highlight
    24.10.2022
    Spintronics: A new tool at BESSY II for chirality investigations
    Information on complex magnetic structures is crucial to understand and develop spintronic materials. Now, a new instrument named ALICE II is available at BESSY II. It allows magnetic X-ray scattering in reciprocal space using a new large area detector. A team at HZB and Technical University Munich has demonstrated the performance of ALICE II by analysing helical and conical magnetic states of an archetypal single crystal skyrmion host. ALICE II is now available for guest users at BESSY II.
  • High entropy alloys: structural disorder and magnetic properties
    Science Highlight
    20.10.2022
    High entropy alloys: structural disorder and magnetic properties
    High-entropy alloys (HEAs) are promising materials for catalysis and energy storage, and at the same time they are extremely hard, heat resistant and demonstrate great variability in their magnetic behaviour. Now, a team at BESSY II in collaboration with Ruhr University Bochum, BAM, Freie Universität Berlin and University of Latvia has gained new insights into the local environment of a so-called high-entropy Cantor alloy made of chromium, manganese, iron, cobalt and nickel, and has thus also been able to partially explain the magnetic properties of a nanocrystalline film of this alloy.
  • Green hydrogen: faster progress with modern X-ray sources
    Science Highlight
    07.10.2022
    Green hydrogen: faster progress with modern X-ray sources
    In order to produce green hydrogen, water can be split up via electrocatalysis, powered by renewable sources such as sun or wind. A review article in the journal Angewandte Chemie Int. Ed. shows how modern X-ray sources such as BESSY II can advance the development of suitable electrocatalysts. In particular, X-ray absorption spectroscopy can be used to determine the active states of catalytically active materials for the oxygen evolution reaction. This is an important contribution to developing efficient catalysts from inexpensive and widely available elements.
  • Dynamics in one-dimensional spin chains newly elucidated
    Science Highlight
    03.10.2022
    Dynamics in one-dimensional spin chains newly elucidated
    Neutron scattering is considered the method of choice for investigating magnetic structures and excitations in quantum materials. Now, for the first time, the evaluation of measurement data from the 2000s with new methods has provided much deeper insights into a model system – the 1D Heisenberg spin chains. A new toolbox is available for elucidating future quantum materials has been achieved.
  • BESSY II: Localisation of d-electrons determined
    Science Highlight
    02.10.2022
    BESSY II: Localisation of d-electrons determined
    Transition metals have many applications in engineering, electrochemistry and catalysis. To understand their properties, the interplay between atomic localisation and delocalisation of the outer electrons in the d orbitals is crucial. This insight is now provided by a special end station at BESSY II with highest precision, as demonstrated by a study of copper, nickel and cobalt with interesting quantitative results. The Royal Society of Chemistry has selected the paper as a HOT Article 2022.
  • Rhombohedral graphite as a model for quantum magnetism
    Science Highlight
    27.09.2022
    Rhombohedral graphite as a model for quantum magnetism
    Graphene is an extremely exciting material. Now a graphene variant shows another talent: rhombohedral graphite made of several layers slightly offset from each other could enlighten the hidden physics in quantum magnets.
  • New road towards spin-polarised currents
    Science Highlight
    08.09.2022
    New road towards spin-polarised currents
    The transition metal dichalcogenide (TMD) series are a family of promising candidate materials for spintronics. A study at lightsource BESSY II has unveiled that in one of those materials even simple linear polarised light is sufficient to selectively manipulate spins of different orientations. This result provides an entirely new route for the generation of spin-polarised currents and is a milestone for the development of spintronic and opto-spintronic devices.
  • Green hydrogen: Nanostructured nickel silicide shines as a catalyst
    Science Highlight
    11.08.2022
    Green hydrogen: Nanostructured nickel silicide shines as a catalyst
    Electrical energy from wind or sun can be stored as chemical energy in hydrogen, an excellent fuel and energy carrier. The prerequisite for this, however, is efficient electrolysis of water with inexpensive catalysts. For the oxygen evolution reaction at the anode, nanostructured nickel silicide now promises a significant increase in efficiency. This was demonstrated by a group from the HZB, Technical University of Berlin and the Freie Universität Berlin as part of the CatLab research platform with measurements among others at BESSY II.
  • Buckyballs on gold are less exotic than graphene
    Science Highlight
    21.07.2022
    Buckyballs on gold are less exotic than graphene
    C60 molecules on a gold substrate appear more complex than their graphene counterparts, but have much more ordinary electronic properties. This is now shown by measurements with ARPES at BESSY II and detailed calculations.
  • Third-highest oxidation state secures rhodium a place on the podium
    Science Highlight
    14.07.2022
    Third-highest oxidation state secures rhodium a place on the podium
    Oxidation states of transition metals describe how many electrons of an element are already engaged in bonding, and how many are still available for further reactions. Scientists from Berlin and Freiburg have now discovered the highest oxidation state of rhodium, indicating that rhodium can involve more of its valence electrons in chemical bonding than previously thought. This finding might be relevant for the understanding of catalytic reactions involving highly-oxidized rhodium. The result was recognized as a „very important paper“ in Angewandte Chemie.

  • Potential energy surfaces of water mapped for the first time
    Science Highlight
    07.07.2022
    Potential energy surfaces of water mapped for the first time
    Liquids are more difficult to describe than gases or crystalline solids. An HZB team has now mapped the potential energy surfaces of water molecules in liquid water under ambient conditions for the first time at the Swiss Light Source SLS of the Paul Scherrer Institute, Switzerland. This contributes to a better understanding of the chemistry of water and in aqueous solutions. These investigations can soon be continued at the newly built METRIXS station at the X-ray source BESSY II.
  • Spintronics: Giant Rashba semiconductors show unconventional dynamics with potential applications
    Science Highlight
    06.07.2022
    Spintronics: Giant Rashba semiconductors show unconventional dynamics with potential applications
    Germanium telluride is a strong candidate for use in functional spintronic devices due to its giant Rashba-effect. Now, scientists at HZB have discovered another intriguing phenomenon in GeTe by studying the electronic response to thermal excitation of the samples. To their surprise, the subsequent relaxation proceeded fundamentally different to that of conventional semimetals. By delicately controlling the fine details of the underlying electronic structure, new functionalities of this class of materials could be conceived. 

  • Atomic displacements in High-Entropy Alloys examined
    Science Highlight
    27.06.2022
    Atomic displacements in High-Entropy Alloys examined
    High-entropy alloys of 3d metals have intriguing properties that are interesting for applications in the energy sector. An international team at BESSY II has now investigated the local order on an atomic scale in a so-called high-entropy Cantor alloy of chromium, manganese, iron, cobalt and nickel. The results from combined spectroscopic studies and statistical simulations expand the understanding of this group of materials.
  • Calculating the "fingerprints" of molecules with artificial intelligence
    Science Highlight
    13.06.2022
    Calculating the "fingerprints" of molecules with artificial intelligence
    With conventional methods, it is extremely time-consuming to calculate the spectral fingerprint of larger molecules. But this is a prerequisite for correctly interpreting experimentally obtained data. Now, a team at HZB has achieved very good results in significantly less time using self-learning graphical neural networks.
  • Water distribution in the fuel cell made visible in 4D
    Science Highlight
    02.06.2022
    Water distribution in the fuel cell made visible in 4D
    Teams from Helmholtz-Zentrum Berlin (HZB) and University College London (UCL) have visualised the water distribution in a fuel cell in three dimensions and in real time for the first time by evaluating neutron data from the Berlin Experimental Reactor shut down in 2019. The analysis opens new possibilities for more efficient and thus more cost-effective fuel cells.
  • New discoveries into how the body stores zinc
    Science Highlight
    25.05.2022
    New discoveries into how the body stores zinc
    Zinc deficiency is a global health problem affecting many people and results in a weak immune system in adults and especially in children. This is a challenge for health systems and is quite evident in the Mexican population, for example. Seeking explanations, researchers in Mexico teamed up with international synchrotron experts and gained new insights from studying Drosophila fruit flies, which are known to be a decent model system for human zinc metabolism.
    Thanks to beamtime at BESSY II and at the SLS (PSI), they were able to show that the zinc stores in Drosophila flies depend on the tryptophan content of their diet.
  • Thermal insulation for quantum technologies
    Science Highlight
    19.05.2022
    Thermal insulation for quantum technologies
    New energy-efficient IT components often only operate stably at extremely low temperatures. Therefore, very good thermal insulation of such elements is crucial, which requires the development of materials with extremely low thermal conductivity. A team at HZB has now used a novel sintering process to produce nanoporous silicon aluminium samples in which pores and nanocrystallites impede the transport of heat and thus drastically reduce thermal conductivity. The researchers have developed a model for predicting the thermal conductivity, which was confirmed using experimental data on the microstructure of the samples and their thermal conductivity. Thus, for the first time, a method is available for the targeted development of complex porous materials with ultra-low thermal conductivity.
  • Magnetic nanoparticles in biological vehicles individually characterised
    Science Highlight
    17.05.2022
    Magnetic nanoparticles in biological vehicles individually characterised
    Magnetic nanostructures are promising tools for medical applications.  Incorporated into biological structures, they can be steered via external magnetic fields inside the body to release drugs or to destroy cancer cells. However, until now, only average information on the magnetic properties of those nanoparticles could be obtained, thus limiting their successful implementations in therapies. Now a team at HZB conceived and tested a new method to assess the characteristic parameters of every single magnetic nanoparticle.
  • How electron spin coupling affects catalytic oxygen activation
    Science Highlight
    09.05.2022
    How electron spin coupling affects catalytic oxygen activation
    A team at the EPR4Energy joint lab of HZB and MPI CEC has developed a new THz EPR spectroscopy method to study the catalytic activation of molecular oxygen by copper complexes. The method allows insights into previously inaccessible spin-spin interactions and the function of novel catalytic and magnetic materials.
  • Perovskite solar cells: Properties still remain enigmatic
    Science Highlight
    02.05.2022
    Perovskite solar cells: Properties still remain enigmatic
    In order to explain the particularly favourable properties of perovskite semiconductors for solar cells, various hypotheses are circulating. Polarons or a giant Rashba effect, for example, are thought to play a major role. A team at BESSY II has now experimentally disproved these hypotheses. In doing so, they further narrow down the possible causes for the transport properties and enable better approaches for the targeted optimisation of this class of materials.
  • Solar hydrogen: Better photoelectrodes through flash heating
    Science Highlight
    04.04.2022
    Solar hydrogen: Better photoelectrodes through flash heating
    Producing low-cost metal-oxide thin films with high electronic quality for solar water splitting is not an easy task. Especially since quality improvements of the upper metal oxide thin films need thermal processing at high temperatures, which would melt the underlying glass substrate. Now, a team at HZB-Institute for Solar Fuels has solved this dilemma: A high intensity and rapid light pulse directly heats the semiconducting metal-oxide thin film, allowing to achieve the optimal heating conditions without damaging the substrate.
  • Quantum complexity grows linearly for an exponentially long time
    Science Highlight
    28.03.2022
    Quantum complexity grows linearly for an exponentially long time
    Physicists know about the huge chasm between quantum physics and the theory of gravity. However, in recent decades, theoretical physics has provided some plausible conjecture to bridge this gap and to describe the behaviour of complex quantum many-body systems, for example black holes and wormholes in the universe. Now, a theory group at Freie Universität Berlin and HZB, together with Harvard University, USA, has proven a mathematical conjecture about the behaviour of complexity in such systems, increasing the viability of this bridge. The work is published in Nature Physics.
  • An ultrafast X-ray glance into photoacid electronic structure
    Science Highlight
    25.03.2022
    An ultrafast X-ray glance into photoacid electronic structure
    Photoacids are molecules that release a proton upon electronic excitation, thus enhancing the acidity of a liquid. Pioneering work by Theodor Förster has shown the direct relationship between the wavelength position of optical absorption and acidity properties with which the increase in acidity  in the first electronic excited state can be quantified. However, underlying full microscopic explanations for the photoacidity phenomenon have remained sparse. With ultrafast X-ray spectroscopy, locally probing the electronic structure of a proton donating group of an amine aromatic photoacid has now provided direct insight in the changes of electronic structure. The long standing open question for photoacidity has now finally been resolved: major electronic structure changes occur on the base side of the so-called Förster cycle, whereas the acid side plays a minor role. 
  • Fermi Arcs in an Antiferromagnet detected at BESSY II
    Science Highlight
    23.03.2022
    Fermi Arcs in an Antiferromagnet detected at BESSY II
    An international cooperation has analysed samples of NdBi crystals which display interesting magnetic properties. In their experiments including measurements at BESSY II they could find evidence for so called Fermi arcs in the antiferromagnetic state of the sample at low temperatures. This observation is not yet explained by existing theoretical ideas and opens up exciting possibilities to make use of these kind of materials for innovative information technologies based on the electron spin rather than the charge.
  • Unravelling tautomeric mixtures: RIXS at BESSY II allows to see clearly
    Science Highlight
    17.03.2022
    Unravelling tautomeric mixtures: RIXS at BESSY II allows to see clearly
    A team at HZB has developed a method of experimentally unravelling tautomeric mixtures. Based on resonant inelastic X-ray scattering (RIXS) at BESSY II, not only proportions of the tautomers can be deduced, but the properties of each individual tautomer can be studied selectively. This method could yield to detailed information on the properties of molecules and their biological function. In the present study, now advertised on the cover of “The Journal of Physical Chemistry Letters” the technique was applied to the prototypical keto-enol equilibrium.
  • Predicting solar cell performance from terahertz and microwave spectroscopy
    Science Highlight
    04.03.2022
    Predicting solar cell performance from terahertz and microwave spectroscopy
    Many semiconducting materials are possible candidates for solar cells. In recent years, perovskite semiconductors in particular have attracted attention, as they are both inexpensive and easy to process and enable high efficiencies. Now a study with 15 participating research institutions shows how terahertz (TRTS) and microwave spectroscopy (TRMC) can be used to reliably determine the mobility and lifetime of the charge carriers in new semiconducting materials. Using these measurement data it is possible to predict the potential efficiency of the solar cell in advance and to classify the losses in the finished cell.  
  • “Workhorse” of silicon photovoltaics combined with perovskite in tandem for the first time
    Science Highlight
    24.02.2022
    “Workhorse” of silicon photovoltaics combined with perovskite in tandem for the first time
    So-called PERC cells are used in mass production of silicon solar cells, they are considered the workhorses of photovoltaics, dominating the market. Now two teams from HZB and the Institute for Solar Energy Research in Hamelin (ISFH) have shown that such standard silicon cells are also suitable as a basis for tandem cells with perovskite top cells. Currently, the efficiency of the tandem cell is still below that of optimised PERC cells alone, but could be increased to up to 29.5% through targeted optimisation. The research was funded by the German Federal Ministry of Economics as part of a joint project.
  • Lithium-Sulfur batteries: First multimodal analysis in pouch cell format
    Science Highlight
    21.02.2022
    Lithium-Sulfur batteries: First multimodal analysis in pouch cell format
    Lithium-sulphur (Li/S) batteries have significantly higher energy densities than conventional lithium-ion batteries, but age very quickly. Now, for the first time, a team at HZB has investigated Li/S batteries in the industry-relevant pouch cell format with different electrolytes during operation. Teams from TU Dresden and the Fraunhofer IWS were also involved in the study. With a specially developed measuring cell, impedance, temperature and pressure can be recorded at different times and combined with radiographic images. The evaluation shows how the electrolyte affects the formation of unwanted sulphur particles and polysulphides. The study has been published in the renowned journal Advanced Energy Materials.
  • Innovative catalysts: An expert review
    Science Highlight
    15.02.2022
    Innovative catalysts: An expert review
    Highly efficient (electro-)catalysts are essential for the production of green hydrogen, the chemical industry, fertiliser production and other sectors of the economy. In addition to transition metals, a variety of other metallic or non-metallic elements have now moved into the focus of research. In a review article, experts from CatLab and Technische Universität Berlin present an overview on current knowledge and a perspective on future research questions.
  • User research at BESSY II: Unveiling the secrets of biofilms
    Science Highlight
    31.01.2022
    User research at BESSY II: Unveiling the secrets of biofilms
    Most bacteria have the ability to form communities, biofilms, that adhere to a wide variety of surfaces and are difficult to remove. This can lead to major problems, for example in hospitals or in the food industry. Now, an international team led by Hebrew University, Jerusalem, and the Technical University Dresden, has studied a model system for biofilms at the synchrotron radiation facilities BESSY II at HZB and the ESRF and found out what role the structures within the biofilm play in the distribution of nutrients and water.
  • An electronic rainbow – perovskite spectrometer by inkjet printing
    Science Highlight
    20.12.2021
    An electronic rainbow – perovskite spectrometer by inkjet printing
    Researchers from Innovation Lab HySPRINT at Helmholtz-Zentrum Berlin (HZB) and Humboldt Universität zu Berlin (HU) have used an advanced inkjet printing technique to produce a large range of photodetector devices based on a hybrid perovskite semiconductor. By mixing of only three inks, the researchers were able to precisely tune the semiconductor properties during the printing process. Inkjet printing is already an established fabrication method in industry, allowing fast and cheap solution processing. Extending the inkjet capabilities from large area coating towards combinatorial material synthesis opens the door for new possibilities for the fabrication of different kind of electronic components in a single printing step.
  • A Wiki for Perovskite Solar Cell Research
    Science Highlight
    15.12.2021
    A Wiki for Perovskite Solar Cell Research
    An international team of experts has collected data on metal halide perovskite solar cells from more than 15,000 publications and developed a database with visualisation options and analysis tools. The database is open source and provides an overview of the rapidly growing knowledge as well as the open questions in this exciting class of materials. The study was initiated by HZB scientist Dr. Eva Unger and implemented and coordinated by her postdoc Jesper Jacobsson.
  • Liquid crystals for fast switching devices
    Science Highlight
    06.12.2021
    Liquid crystals for fast switching devices
    An international team has investigated a newly synthesized liquid-crystalline material that promises applications in optoelectronics. Simple rod-shaped molecules with a single center of chirality self-assemble into helical structures at room temperature. Using soft X-ray resonant scattering at BESSY II, the scientists have now been able to determine the pitch of the helical structure with high precision. Their results indicate an extremely short pitch at only about 100 nanometres which would enable applications with particularly fast switching processes.

  • Green information technologies: Superconductivity meets Spintronics
    Science Highlight
    02.12.2021
    Green information technologies: Superconductivity meets Spintronics
    Superconducting coupling between two regions separated by a one micron wide ferromagnetic compound has been proved by an international team. This macroscopic quantum effect, known as Josephson effect, generates an electrical current within the ferromagnetic compound made of superconducting Cooper-pairs. Magnetic imaging of the ferromagnetic region at BESSY II has contributed to demonstrate that the spin of the electrons forming the Cooper pairs are equal. These results pave the way for low-power consumption superconducting spintronic-applications where spin-polarized currents can be protected by quantum coherence.

  • Neutron data help to reveal “spooky” entanglement in quantum magnets
    Science Highlight
    25.11.2021
    Neutron data help to reveal “spooky” entanglement in quantum magnets
    Using data from the British neutron source ISIS from the year 2000, research teams have now demonstrated the viability of a “quantum entanglement witness” capable of proving the presence of entanglement between magnetic particles, or spins, in a quantum material. A team from HZB led by Prof. Bella Lake was also involved in the analysis.
  • "Green" chemistry: BESSY II sheds light on mechanochemical synthesis
    Science Highlight
    16.11.2021
    "Green" chemistry: BESSY II sheds light on mechanochemical synthesis
    In mechanochemistry, reagents are finely ground and mixed so that they combine to form the desired product, even without need for solvent. By eliminating solvent, this technology promises to contribute significantly towards ‘green’ and environmentally benign chemical manufacture in the future. However, there are still major gaps in understanding the key processes that occur during mechanical treatment and reaction. A team led by the Federal Institute for Materials Research (BAM) has now developed a method at BESSY II to observe these processes in situ with X-ray scattering. 

  • Spintronics: Exotic ferromagnetic order in two-dimensions
    Science Highlight
    29.10.2021
    Spintronics: Exotic ferromagnetic order in two-dimensions
    An international team has detected at HZB's vector magnet facility VEKMAG an unusual ferromagnetic property in a two-dimensional system, known as “easy-plane anisotropy”. This could foster new energy efficient information technologies based on spintronics for data storage, among other things. The team has published its results in the renowned journal Science.

  • Ultrafast magnetism: heating magnets, freezing time
    Science Highlight
    15.10.2021
    Ultrafast magnetism: heating magnets, freezing time
    Magnetic solids can be demagnetized quickly with a short laser pulse, and there are already so-called HAMR (Heat Assisted Magnetic Recording) memories on the market that function according to this principle. However, the microscopic mechanisms of ultrafast demagnetization remain unclear. Now, a team at HZB has developed a new method at BESSY II to quantify one of these mechanisms and applied it to the rare-earth element Gadolinium, whose magnetic properties are caused by electrons on both the 4f and the 5d shells. This study is completing a series of experiments done by the team on Nickel, Iron-Nickel Alloys. Understanding these mechanisms is useful for developing ultrafast data storage devices.

  • Perovskite solar cells: Defects trap charge carriers - and release them again
    Science Highlight
    07.10.2021
    Perovskite solar cells: Defects trap charge carriers - and release them again
    An international team at HZB and Charles University Prague has investigated how charge carriers in so called MAPI-perovskite semiconductors interact with different defects. They show that a large proportion of defects quickly releases trapped charge carriers. These results could help to further improve the properties of perovskite solar cells.

  • A sharp look into tiny ferroelectric crystals
    Science Highlight
    06.10.2021
    A sharp look into tiny ferroelectric crystals
    What happens to ferroelectric materials when their dimensions are greatly reduced? A team of researchers at HZB has now been able to show how this question can be answered in a detailed way.

  • Beam diagnostics for future laser wakefield accelerators
    Science Highlight
    30.09.2021
    Beam diagnostics for future laser wakefield accelerators
    For decades, particle accelerators have been getting bigger and bigger. In the meantime, ring accelerators with circumferences of many kilometres have reached a practical limit. Linear accelerators in the GHz range also require very long construction lengths. For some years now, however, an alternative is explored: "tabletop particle accelerators" based on the laser excitation of charge waves in plasmas (laser wakefield). Such compact particle accelerators would be particularly interesting for future accelerator-driven light sources, but are also being investigated for high-energy physics. A team from Helmholtz-Zentrum Berlin (HZB) and the Physikalisch-Technische Bundesanstalt (PTB) has developed a method to precisely measure the cross-section of electron bunches accelerated in this way.  This brings applications of these new accelerator technologies for medicine and research closer.

  • New world record in materials research - X-ray microscopy with 1000 tomograms per second
    Science Highlight
    27.09.2021
    New world record in materials research - X-ray microscopy with 1000 tomograms per second
    Tomoscopy is an imaging method in which three-dimensional images of the inside of materials are calculated in rapid succession. Now a team led by HZB physicist Francisco García Moreno has achieved a new world record at the TOMCAT beamline of the Swiss Light Source at the Paul Scherrer Institute: with 1000 tomograms per second, it is now possible to non-destructively document very fast processes and developments in materials on the micrometre scale, such as the burning of a sparkler or the foaming of a metal alloy for the production of stable lightweight materials. 

  • Surface analysis at BESSY II: sharper insights into thin-film systems
    Science Highlight
    16.09.2021
    Surface analysis at BESSY II: sharper insights into thin-film systems

    Interfaces in semiconductor components or solar cells play a crucial role for functionality. Nevertheless, until now it has often been difficult to investigate adjacent thin films separately using spectroscopic methods. An HZB team at BESSY II has combined two different spectroscopic methods and used a model system to demonstrate how well they can be distinguished.

  • Disorder brings out quantum physical talents
    Science Highlight
    01.09.2021
    Disorder brings out quantum physical talents
    Quantum effects are most noticeable at extremely low temperatures, which limits their usefulness for technical applications. Thin films of MnSb2Te4, however, show new talents due to a small excess of manganese. Apparently, the resulting disorder provides spectacular properties: The material proves to be a topological insulator and is ferromagnetic up to comparatively high temperatures of 50 Kelvin, measurements at BESSY II show.  This makes this class of material suitable for quantum bits, but also for spintronics in general or applications in high-precision metrology.

  • On the trail of lithium dendrites: How destructive formations develop in batteries
    Science Highlight
    01.09.2021
    On the trail of lithium dendrites: How destructive formations develop in batteries
    Tiny formations inside lithium batteries can severely limit the operating life of an energy storage device. A research team at the Helmholtz-Zentrum Berlin (HZB) has now investigated the process behind these formations in greater detail. Their results provide anchor points for the future development of longer-lasting and safer lithium batteries.
  • Perovskite solar cells: Interfacial loss mechanisms revealed
    Science Highlight
    20.08.2021
    Perovskite solar cells: Interfacial loss mechanisms revealed

    Metal-organic perovskite materials promise low-cost and high-performance solar cells. Now a group at HZB managed to de-couple the different effects of self-assembled monolayers of organic molecules (SAMs) that reduce losses at the interfaces. Their results help to optimise such functional interlayers.

  • Green hydrogen: Why do certain catalysts improve in operation?
    Science Highlight
    09.08.2021
    Green hydrogen: Why do certain catalysts improve in operation?
    Crystalline cobalt arsenide is a catalyst that generates oxygen during electrolytic water splitting in the production of hydrogen. The material is considered to be a model system for an important group of catalysts whose performance increases under certain conditions in the course of electrolysis. Now a HZB-team headed by Marcel Risch has observed at BESSY II how two simultaneous mechanisms are responsible for this. The catalytic activity of the individual catalysis centres decreases in the course of electrolysis, but at the same time the morphology of the catalyst layer also changes. Under favourable conditions, considerably more catalysis centres come into contact with the electrolyte as a result, so that the overall performance of the catalyst increases.

  • When vibrations increase on cooling: Anti-freezing observed
    Science Highlight
    04.08.2021
    When vibrations increase on cooling: Anti-freezing observed
    An international team has observed an amazing phenomenon in a nickel oxide material during cooling: Instead of freezing, certain fluctuations actually increase as the temperature drops. Nickel oxide is a model system that is structurally similar to high-temperature superconductors. The experiment shows once again that the behaviour of this class of materials still holds surprises.

  • Water as a metal - detected at BESSY II
    Science Highlight
    28.07.2021
    Water as a metal - detected at BESSY II
    Under normal conditions, pure water is an almost perfect insulator. Water only develops metallic properties under extreme pressure, such as exists deep inside of large planets. Now, an international collaboration has used a completely different approach to produce metallic water and documented the phase transition at BESSY II. The study is published now in Nature.

  • Lead-free perovskite solar cells - How fluoride additives improve quality
    Science Highlight
    26.07.2021
    Lead-free perovskite solar cells - How fluoride additives improve quality
    Tin halide perovskites are currently considered the best alternative to their lead-containing counterparts, which are, however, still significantly less efficient and stable. Now, a team led by Prof. Antonio Abate from HZB has analysed the chemical processes in the perovskite precursor solution and the fluoride compounds in detail. Using a clever combination of measurement methods at BESSY II and with NMR at the Humboldt-University Berlin, they were able to show that fluoride prevents the oxidation of tin and leads to a more homogeneous film formation with fewer defects, increasing the quality of the semiconductor layer.

  • Future information technologies: Topological materials for ultrafast spintronics
    Science Highlight
    16.07.2021
    Future information technologies: Topological materials for ultrafast spintronics
    A team led by HZB physicist Dr. Jaime Sánchez-Barriga has gained new insights into the ultrafast response of topological states of matter to femtosecond laser excitation. Using time- and spin-resolved methods at BESSY II, the physicists explored how, after optical excitation, the complex interplay in the behavior of excited electrons in the bulk and on the surface results in unusual spin dynamics. The work is an important step on the way to spintronic devices based on topological materials for ultrafast information processing.

  • Solar hydrogen for Antarctica - study shows advantages of thermally coupled approach
    Science Highlight
    02.07.2021
    Solar hydrogen for Antarctica - study shows advantages of thermally coupled approach
    A team from the Helmholtz-Zentrum Berlin, Ulm University, and Heidelberg University has now investigated how hydrogen can be produced at the South Pole using sunlight, and which method is the most promising. Their conclusion: in extremely cold regions, it can be considerably more efficient to attach the PV modules directly to the electrolyser, i.e. to thermally couple them. This is because the waste heat from the PV modules increases the efficiency of electrolysis in this environment. The results of this study, which has now been published in Energy & Environmental Science, are also relevant for other cold regions on Earth, such as Alaska, Canada, and high mountain regions, for example. In these places, solar hydrogen could replace fossil fuels such as oil and petrol.

  • BESSY II: universal mechanism of regulation in plant cells discovered
    Science Highlight
    21.06.2021
    BESSY II: universal mechanism of regulation in plant cells discovered
    In pioneering work, a German-Japanese research team at BESSY II has been able to determine the 3D structure of a metalloprotein that plays an important role as a catalyst in all plant cells. This involves the DYW deaminase domain of what is referred to as the RNA editosome. The DYW domain alters messenger RNA nucleotides in chloroplasts and mitochondria and contains a zinc ion whose activity is controlled by a very unusual mechanism. The team has now been able to describe this mechanism in detail for the first time. Their study, published in Nature Catalysis, is considered a breakthrough in the field of plant molecular biology and has far-reaching implications for bioengineering.

  • Perovskite Solar Cells: Insights into early stages of structure formation
    Science Highlight
    18.06.2021
    Perovskite Solar Cells: Insights into early stages of structure formation
    Using small-angle scattering at the PTB X-ray beamline of BESSY II, an HZB team was able to experimentally investigate the colloidal chemistry of perovskite precursor solutions used for solar cell production. The results contribute to the targeted and systematic optimization of the manufacturing process and quality of these exciting semiconductor materials.

  • How quantum dots can "talk" to each other
    Science Highlight
    03.06.2021
    How quantum dots can "talk" to each other

    A group at HZB has worked out theoretically how the communication between two quantum dots can be influenced with light.  The team led by Annika Bande also shows ways to control the transfer of information or energy from one quantum dot to another. To this end, the researchers calculated the electronic structure of two nanocrystals, which act as quantum dots. With the results, the movement of electrons in quantum dots can be simulated in real time.

  • BESSY II: New insights into switchable MOF structures at the MX beamlines
    Science Highlight
    27.05.2021
    BESSY II: New insights into switchable MOF structures at the MX beamlines
    Metal-organic framework compounds (MOFs) are widely used in gas storage, material separation, sensor technology or catalysis. A team led by Prof. Dr. Stefan Kaskel, TU Dresden, has now investigated a special class of these MOFs at the MX beamlines of BESSY II. These are "switchable" MOFs that can react to external stimuli. Their analysis shows how the behaviour of the material is related to transitions between ordered and disordered phases. The results have now been published in Nature Chemistry.

  • Perovskite solar cells: Hydrogen bonds measured
    Science Highlight
    26.05.2021
    Perovskite solar cells: Hydrogen bonds measured
    The evaluation of X-ray measurements on methylammonium perovskite semiconductors now shows what role hydrogen bonds play in these materials. In addition, the HZB team showed that radiation damage by soft X-rays to this sensitive class of materials occurs even faster than often expected. Both results provide important information for perovskites materials research for solar cells.

  • Direct observation of the ad- and desorption of guest atoms into a mesoporous host
    Science Highlight
    21.04.2021
    Direct observation of the ad- and desorption of guest atoms into a mesoporous host
    Battery electrodes, storage devices for gases, and some catalyst materials have tiny functional pores that can accommodate atoms, ions, and molecules. How these guest atoms are absorbed into or released from the pores is crucial to understanding the porous materials' functionality. However, usually these processes can only be observed indirectly. A team from the Helmholtz Zentrum Berlin (HZB) has employed two experimental approaches using the ASAXS instrument at the PTB X-ray beamline of the HZB BESSY II synchrotron to directly observe the adsorption process of atoms in a mesoporous model system. The work lays the foundations for new insights into these kinds of energy materials.

  • Green hydrogen: "Rust" as a photoanode and its limits
    Science Highlight
    19.04.2021
    Green hydrogen: "Rust" as a photoanode and its limits
    Metal oxides such as rust are intriguing photoelectrode materials for the production of green hydrogen with sunlight. They are cheap and abundant, but in spite of decades of research, progress has been limited. A team at HZB, together with partners from Ben Gurion University and the Technion, Israel, has now analysed the optoelectronic properties of rust (haematite) and other metal oxides in unprecedented detail. Their results show that the maximum achievable efficiency of haematite electrodes is significantly lower than previously assumed. The study demonstrates ways to assess new photoelectrode materials more realistically.

  • X-ray lightsource at DESY identifies promising candidates for COVID drugs
    Science Highlight
    06.04.2021
    X-ray lightsource at DESY identifies promising candidates for COVID drugs
    At DESY's high-brilliance X-ray light source PETRA III, a team from more than 30 research institutions has identified several candidates for active substances against the coronavirus SARS-CoV-2. They bind to an important protein of the virus and could thus be the basis for a drug against Covid-19. The MX team from HZB examined part of the measurement data with special analysis algorithms in order to identify suitable active substances. The study has now been published in the renowned journal Science.

  • Tomography brings insights into the early evolution of bones
    Science Highlight
    31.03.2021
    Tomography brings insights into the early evolution of bones
    Modern biology considers bone cells (osteocytes) as essential for bone development and health. However, when bone initially evolved some 400-million years ago, it did not contain bone cells. So why did bone cells evolve? Why was it so advantageous that most subsequent vertebrates have bone cells? A joint team of palaeontologists at Berlin’s natural history museum has now for the first time analysed these structures in 400 million-year-old fossils of marine life at unprecedentedly high resolution and in 3D. To be able to view these structures, tomography experts at the Helmholtz-Zentrum Berlin (HZB) examined the samples under the focussed ion beam of a scanning electron microscope to calculate 3D images from the data, achieving resolutions in the nanometre range using technology that was initially developed to study battery corrosion.

     

  • New insights into the structure of organic-inorganic hybrid perovskites
    Science Highlight
    22.03.2021
    New insights into the structure of organic-inorganic hybrid perovskites
    In photovoltaics, organic-inorganic hybrid perovskites have made a rapid career. But many questions about the crystalline structure of this surprisingly complex class of materials remain unanswered. Now, a team at HZB has used four-dimensional modelling to interpret structural data of methylammonium lead bromide (MAPbBr3), identifying incommensurable superstructures and modulations of the predominant structure. The study is published in the ACS Journal of Physical Chemistry Letters and was selected by the editors as an Editor's Choice.

  • Solar cells: Losses made visible on the nanoscale
    Science Highlight
    17.03.2021
    Solar cells: Losses made visible on the nanoscale
    Solar cells made of crystalline silicon achieve peak efficiencies, especially in combination with selective contacts made of amorphous silicon (a-Si:H). However, their efficiency is limited by losses in these contact layers. Now, for the first time, a team at Helmholtz-Zentrum Berlin (HZB) and the University of Utah, USA, has experimentally shown how such contact layers generate loss currents on the nanometre scale and what their physical origin is. Using a conductive atomic force microscope, they scanned the solar cell surfaces in ultra-high vacuum and detected tiny, nanometre-sized channels for the detrimental dark currents, which are due to disorder in the a-Si:H layer.

  • Instrument at BESSY II shows how light activates MoS2 layers to become catalysts
    Science Highlight
    05.03.2021
    Instrument at BESSY II shows how light activates MoS2 layers to become catalysts
    Thin films of molybdenum and sulfur belong to a class of materials that can be considered for use as photocatalysts. Inexpensive catalysts such as these are needed to produce hydrogen as a fuel using solar energy. However, they are still not very efficient as catalysts. A new instrument at the Helmholtz-Berlin Zentrum’s BESSY II now shows how a light pulse alters the surface properties of the thin film and activates the material as a catalyst.

  • New skills of Graphene: Tunable lattice vibrations
    Science Highlight
    01.03.2021
    New skills of Graphene: Tunable lattice vibrations
    Technological innovation in the last century was mainly based on the control of electrons or photons. Now, in the emerging research field of phononics, phonons or vibrations of the crystal lattice attract attention. A team at Freie Universität Berlin and Helmholtz-Zentrum Berlin showed a graphene-based phononic crystal whose resonant frequency can be tuned over a broad range and has used a helium-ion microscope to produce such a crystal. This is a real breakthrough in the field of phononics, now published in Nano Letters.

  • Accelerator physics: Experiment reveals new options for synchrotron light sources
    Science Highlight
    24.02.2021
    Accelerator physics: Experiment reveals new options for synchrotron light sources
    An international team has shown through a sensational experiment how diverse the possibilities for employing synchrotron light sources are. Accelerator experts from the Helmholtz-Zentrum Berlin (HZB), the German federal metrology institute Physikalisch-Technische Bundesanstalt (PTB), and Tsinghua University in Beijing have used a laser to manipulate electron bunches at PTB's Metrology Light Source so that they emitted intense light pulses having a laser-like character. Using this method, specialised synchrotron radiation sources would potentially be able to fill a gap in the arsenal of available light sources and offer a prototype for industrial applications. The work was published on 24 February 2021 in the leading scientific publication Nature.

  • The perfect recipe for efficient perovskite solar cells
    Science Highlight
    22.02.2021
    The perfect recipe for efficient perovskite solar cells
    A long-cherished dream of materials researchers is a solar cell that converts sunlight into electrical energy as efficiently as silicon, but that can be easily and inexpensively fabricated from abundant materials. Scientists at the Helmholtz-Zentrum Berlin have now come a step closer to achieving this. They have improved a process for vertically depositing a solution made from an inexpensive perovskite solute onto a moving substrate below. Not only have they discovered the crucial role played by one of the solvents used, but they have also taken a closer look at the aging and storage properties of the solution.

  • World's first video recording of a space-time crystal
    Science Highlight
    10.02.2021
    World's first video recording of a space-time crystal
    A German-Polish research team has succeeded in creating a micrometer-sized space-time crystal consisting of magnons at room temperature. With the help of the scanning transmission X-ray microscope MAXYMUS at Bessy II at Helmholtz Zentrum Berlin, they were able to film the recurring periodic magnetization structure in a crystal. The research project was a collaboration between scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart, Germany, the Adam Mickiewicz University and the Polish Academy of Sciences in Poznań in Poland.

  • An efficient tool to link X-ray experiments and ab initio theory
    Science Highlight
    28.01.2021
    An efficient tool to link X-ray experiments and ab initio theory
    The electronic structure of complex molecules and their chemical reactivity can be assessed by the method of resonant inelastic X-ray scattering (RIXS) at BESSY II. However, the evaluation of RIXS data has so far required very long computing times. A team at BESSY II has now developed a new simulation method that greatly accelerates this evaluation. The results can even be calculated during the experiment. Guest users could use the procedure like a black box.

  • Solar hydrogen: Photoanodes made of α-SnWO4 promise high efficiencies
    Science Highlight
    26.01.2021
    Solar hydrogen: Photoanodes made of α-SnWO4 promise high efficiencies
    Photoanodes made of metal oxides are considered to be a viable solution for the production of hydrogen with sunlight. α-SnWO4 has optimal electronic properties for photoelectrochemical water splitting with sunlight, but corrodes easily. Protective layers of nickel oxide prevent corrosion, but reduce the photovoltage and limit the efficiency. Now a team at HZB has investigated at BESSY II what happens at the interface between the photoanode and the protective layer. Combined with theoretical methods, the measurement data reveal the presence of an oxide layer that impairs the efficiency of the photoanode.


  • How complex oscillations in a quantum system simplify with time
    Science Highlight
    25.01.2021
    How complex oscillations in a quantum system simplify with time
    With a clever experiment, physicists have shown that in a one-dimensional quantum system, the initially complex distribution of vibrations or phonons can change over time into a simple Gaussian bell curve. The experiment took place at the Vienna University of Technology, while the theoretical considerations were carried out by a joint research group from the Freie Universität Berlin and HZB.

  • Perovskite/silicon tandem solar cells on the threshold of 30% efficiency
    Science Highlight
    11.12.2020
    Perovskite/silicon tandem solar cells on the threshold of 30% efficiency
    An HZB team has published a report in the journal Science on the development of its current world record of 29.15% efficiency for a tandem solar cell made of perovskite and silicon. The tandem cell provided stable performance for 300 hours – even without encapsulation. To accomplish this, the group headed by Prof. Steve Albrecht investigated physical processes at the interfaces to improve the transport of the charge carriers.

  • Perovskite Solar Cells: paving the way for rational ink design for industrial-scale manufacturing
    Science Highlight
    27.11.2020
    Perovskite Solar Cells: paving the way for rational ink design for industrial-scale manufacturing
    For the production of high-quality metal-halide perovskite thin-films for large area photovoltaic modules often optimized inks are used which contain a mixture of solvents. An HZB team at BESSY II has now analysed the crystallisation processes within such mixtures. A model has also been developed to assess the kinetics of the crystallisation processes for different solvent mixtures. The results are of high importance for the further development of perovskite inks for industrial-scale deposition processes of these semiconductors.

  • User research at BESSY II: Graphite electrodes for rechargeable batteries investigated
    Science Highlight
    20.11.2020
    User research at BESSY II: Graphite electrodes for rechargeable batteries investigated
    Rechargeable graphite dual ion batteries are inexpensive and powerful. A team of the Technical University of Berlin has investigated at the EDDI Beamline of BESSY II how the morphology of the graphite electrodes changes reversibly during cycling (operando). The 3D X-ray tomography images combined with simultaneous diffraction now allow a precise evaluation of the processes, especially of changes in the volume of the electrodes. This can help to further optimise graphite electrodes.

  • Green hydrogen: buoyancy-driven convection in the electrolyte
    Science Highlight
    19.11.2020
    Green hydrogen: buoyancy-driven convection in the electrolyte
    Hydrogen produced by using solar energy could contribute to a climate neutral energy system of the future. But there are hurdles on the way from laboratory scale to large-scale implementation. A team at HZB has now presented a method to visualise convection in the electrolyte and to reliably simulate it in advance with a multiphysics model. The results can support the design and scaling up of this technology and have been published in the renowned journal Energy and Environmental Science.

  • Solar cells: Mapping the landscape of Caesium based inorganic halide perovskites
    Science Highlight
    16.11.2020
    Solar cells: Mapping the landscape of Caesium based inorganic halide perovskites
    Scientists at HZB have printed and explored different compositions of caesium based halide perovskites (CsPb(BrxI1−x)3 (0 ≤ x ≤ 1)). In a temperature range between room temperature and 300 Celsius, they observe structural phase transitions influencing the electronic properties. The study provides a quick and easy method to assess new compositions of perovskite materials in order to identify candidates for applications in thin film solar cells and optoelectronic devices.

  • Future Information Technologies: Germanium telluride's hidden properties at the nanoscale revealed
    Science Highlight
    05.11.2020
    Future Information Technologies: Germanium telluride's hidden properties at the nanoscale revealed
    Germanium Telluride is an interesting candidate material for spintronic devices. In a comprehensive study at BESSY II, a Helmholtz-RSF Joint Research Group has now revealed how the spin texture switches by ferroelectric polarization within individual nanodomains.

  • Order in the disorder: density fluctuations in amorphous silicon discovered
    Science Highlight
    29.10.2020
    Order in the disorder: density fluctuations in amorphous silicon discovered
    For the first time, a team at HZB has identified the atomic substructure of amorphous silicon with a resolution of 0.8 nanometres using X-ray and neutron scattering at BESSY II and BER II. Such a-Si:H thin films have been used for decades in solar cells, TFT displays, and detectors. The results show that three different phases form within the amorphous matrix, which dramatically influences the quality and lifetime of the semiconductor layer. The study was selected for the cover of the actual issue of Physical Review Letters.

  • Modelling shows which quantum systems are suitable for quantum simulations
    Science Highlight
    27.10.2020
    Modelling shows which quantum systems are suitable for quantum simulations
    A joint research group led by Prof. Jens Eisert of Freie Universität Berlin and Helmholtz-Zentrum Berlin (HZB) has shown a way to simulate the quantum physical properties of complex solid state systems. This is done with the help of complex solid state systems that can be studied experimentally. The study was published in the renowned journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).
  • Solar hydrogen: Let’s consider the stability of photoelectrodes
    Science Highlight
    26.10.2020
    Solar hydrogen: Let’s consider the stability of photoelectrodes

    As part of an international collaboration, a team at the HZB has examined the corrosion processes of high-quality BiVO4 photoelectrodes using different state-of-the-art characterisation methods. The result is the first operando stability study of high-purity BiVO4 photoanodes during the photoelectrochemical oxygen evolution reaction (OER). This work shows how the stability of photoelectrodes and catalysts can be compared and enhanced in the future.

  • Nanopatterns of proteins detected by cryo-electron microscopy
    Science Highlight
    15.10.2020
    Nanopatterns of proteins detected by cryo-electron microscopy
    A team from Helmholtz-Zentrum Berlin (HZB) used cryo electron microscopy to detect regular, two-dimensional structures in the form of Pascal triangles in a shock frozen protein material.  The samples have been synthesized by a Chinese research group. The method of cryo electron microscopy has the potential for new insights into energy materials as well.
  • Perovskite materials: Neutrons show twinning in halide perovskites
    Science Highlight
    12.10.2020
    Perovskite materials: Neutrons show twinning in halide perovskites
    Solar cells based on hybrid halide perovskites achieve high efficiencies. These mixed organic-inorganic semiconductors are usually produced as thin films of microcrystals. An investigation with the Laue camera at the neutron source BER II could now clarify that twinning occurs during crystallisation even at room temperature. This insight is helpful for optimising production processes of halide perovskites. 

  • Silicon-perovskite tandem solar cells: New facilities pave the way for industrial-scale production
    Science Highlight
    07.09.2020
    Silicon-perovskite tandem solar cells: New facilities pave the way for industrial-scale production

    Perovskites are regarded as promising materials for solar cells, able to be manufactured at low cost while at the same time being extremely efficient. They are particularly suitable for tandem solar cells that combine a cell made of silicon and one of perovskite. As a result, sunlight is more completely used when generating electrical energy. So far, the advantages of such cells have only been available for use at small laboratory scale. With two new, highly innovative production facilities, researchers at the Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) are now creating the basis for future production on an industrial scale.

  • Upconversion of photons at low light intensities – the key to new applications in energy and bioengineering
    Science Highlight
    04.09.2020
    Upconversion of photons at low light intensities – the key to new applications in energy and bioengineering
    The region of the spectrum that can be utilised for producing electrical energy can be considerably extended by converting low-energy (longer wavelength) photons into high-energy (shorter wavelength) photons. But so far, this has only been possible at high intensities of light. Now for the first time, scientists from the Helmholtz-Zentrum Berlin (HZB) and the Federal Institute for Materials Research and Testing (BAM) have been able to produce a usable effect from relatively weak light by combining certain nanoparticles with what is known as a meta-surface. This paves the way for future applications in photovoltaics, for the detection of biological substances, and for electrical-field sensors.
  • Molecular architecture: New class of materials for tomorrow's energy storage
    Science Highlight
    26.08.2020
    Molecular architecture: New class of materials for tomorrow's energy storage
    Researchers at the Technische Universität Berlin (TUB) have created a new family of semiconductors, the properties of which were investigated by the Helmholtz-Zentrum Berlin (HZB). The researchers christened the first member “TUB75”. The material belongs to the class called metal-organic frameworks, or MOFs for short, and could open up new opportunities for energy storage. The work was published in Advanced Materials.
  • Research team provides concrete approach to improve the performance of CIGS solar cells
    Science Highlight
    21.08.2020
    Research team provides concrete approach to improve the performance of CIGS solar cells

    A team of researchers used electron microscopes and computer simulations to investigate where losses occur in thin-film solar cells. The researchers from the Martin Luther University Halle-Wittenberg, the Centre for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW) and the Helmholtz Zentrum Berlin (HZB) provide specific information on how the already high efficiency of CIGS solar cells can be improved. The results were published in the journal Nature Communication.

  • Mathematical tool helps calculate properties of quantum materials more quickly
    Science Highlight
    14.08.2020
    Mathematical tool helps calculate properties of quantum materials more quickly
    Many quantum materials have been nearly impossible to simulate mathematically because the computing time required is too long. Now a joint research group at Freie Universität Berlin and the Helmholtz-Zentrum Berlin (HZB) has demonstrated a way to considerably reduce the computing time. This could accelerate the development of materials for energy-efficient IT technologies of the future.

  • Hope for better batteries – researchers follow the charging and discharging of silicon electrodes live
    Science Highlight
    29.07.2020
    Hope for better batteries – researchers follow the charging and discharging of silicon electrodes live

    Using silicon as a material for electrodes in lithium-ion batteries promises a significant increase in battery amp-hour capacity.The shortcoming of this material is that it is easily damaged by the stress caused by charging and discharging.Scientists at the Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) have now succeeded for the first time in observing this process directly on crystalline silicon electrodes in detail.Operando experiments using the BESSY II synchrotronprovided new insights into how fractures occur in silicon – and also how the material can nevertheless be utilised advantageously.

  • New substance library to accelerate the search for active compounds
    Science Highlight
    13.07.2020
    New substance library to accelerate the search for active compounds
    In order to accelerate the systematic development of drugs, the MX team at the Helmholtz-Zentrum Berlin (HZB) and the Drug Design Group at the University of Marburg have established a new substance library. It consists of 1103 organic molecules that could be used as building blocks for new drugs. The MX team has now validated this library in collaboration with the FragMAX group at MAX IV. The substance library of the HZB is available for research worldwide and also plays a role in the search for substances active against SARS-CoV-2.

  • Robust high-performance data storage through magnetic anisotropy
    Science Highlight
    10.07.2020
    Robust high-performance data storage through magnetic anisotropy
    The latest generation of magnetic hard drives is made of magnetic thin films, which are invar materials. They allow extremely robust and high data storage density by local heating of ultrasmall nano-domains with a laser, so called heat assisted magnetic recording or HAMR. The volume in such invar materials hardly expands despite heating. A technologically relevant material for such HAMR data memories are thin films of iron-platinum nanograins. An international team led by the joint research group of Prof. Dr. Matias Bargheer at HZB and the University of Potsdam has now observed experimentally for the first time how a special spin-lattice interaction in these iron-platinum thin films cancels out the thermal expansion of the crystal lattice. The study has been published in Science Advances.

  • Printed perovskite LEDs – an innovative technique towards a new standard process of electronics manufacturing
    Science Highlight
    12.06.2020
    Printed perovskite LEDs – an innovative technique towards a new standard process of electronics manufacturing

    A team of researchers from the Helmholtz-Zentrum Berlin (HZB) and Humboldt-Universität zu Berlin has succeeded for the first time in producing light-emitting diodes (LEDs) from a hybrid perovskite semiconductor material using inkjet printing.This opens the door to broad application of these materials in manufacturing many different kinds of electronic components.The scientists achieved the breakthrough with the help of a trick: "inoculating" (or seeding) the surface with specific crystals.

  • User research at BESSY II: Formation of a 2D meta-stable oxide in reactive environments
    Science Highlight
    10.06.2020
    User research at BESSY II: Formation of a 2D meta-stable oxide in reactive environments

    The chemical behaviour of solid material surfaces is an important physical characteristic for applications of catalysis, chemical sensors, fuel cells and electrodes. A research team from the Max Planck Institute for Chemical Energy Conversion has now described an important phenomenon that can occur when metal alloys are exposed to reactive environments at the synchrotron source BESSY II.

  • BESSY II: Experiment shows for the first time in detail how electrolytes become metallic
    Science Highlight
    05.06.2020
    BESSY II: Experiment shows for the first time in detail how electrolytes become metallic
    An international team has developed a sophisticated experimental technique at BESSY II to observe the formation of a metallic conduction band in electrolytes. To accomplish this, the team first prepared cryogenic solutions of liquid ammonia containing different concentrations of alkali metals. The colour of the solutions changes with concentration from blue to golden as the individual atoms of metal in solution transition to a metallic compound. The team then examined these liquid jets using soft X-rays at BESSY II and subsequently has been able to analyse this process in detail from the data they acquired combined with theoretical predictions. The work has been published in Science and appears even on the cover.
  • Catalysts: Efficient hydrogen production via structure
    Science Highlight
    02.06.2020
    Catalysts: Efficient hydrogen production via structure

    Regeneratively produced hydrogen is considered the ecological raw material of the future. In order to produce it efficiently by electrolysis of water, researchers today also investigate perovskite oxides. The Journal of Physics: Energy invited Dr. Marcel Risch from the Helmholtz-Zentrum Berlin (HZB) to outline the current state of research.

  • On the road to non-toxic and stable perovskite solar cells
    Science Highlight
    11.05.2020
    On the road to non-toxic and stable perovskite solar cells
    The promising halide perovskite materials for solar energy conversion show high efficiencies, but this comes at a cost: The best perovskite materials incorporate toxic lead which poses a hazard to the environment. To replace lead by less toxic elements is not easy since lead-free perovskites show lower stability and poor efficiencies. Now, an international collaboration has engineered a new hybrid perovskite material with promising efficiency and stability.
  • Future information technologies: 3D Quantum Spin Liquid revealed
    Science Highlight
    11.05.2020
    Future information technologies: 3D Quantum Spin Liquid revealed
    Quantum Spin Liquids are candidates for potential use in future information technologies. So far, Quantum Spin Liquids have usually only been found in one or two dimensional magnetic systems only. Now an international team led by HZB scientists has investigated crystals of PbCuTe2O6 with neutron experiments at ISIS, NIST and ILL. They found spin liquid behaviour in 3D, due to a so called hyper hyperkagome lattice. The experimental data fit extremely well to theoretical simulations also done at HZB.
  • User research at BESSY II: Insights into the visual perception of plants
    Science Highlight
    07.05.2020
    User research at BESSY II: Insights into the visual perception of plants
    Plants use light not only for photosynthesis. Although the plant cell does not have eyes, it can still perceive light and thus its environment. Phytochromes, certain turquoise proteins, play the central role in this process. How exactly they function is still unclear. Now a team led by plant physiologist Jon Hughes (Justus Liebig University Gießen) has been able to decipher the three-dimensional architecture of various plant phytochrome molecules at BESSY II. Their results demonstrate how light alters the structure of the phytochrome so that the cell transmits a signal to control the development of the plant accordingly.
  • User research at BESSY II: How new materials increase the efficiency of direct ethanol fuel cells
    Science Highlight
    04.05.2020
    User research at BESSY II: How new materials increase the efficiency of direct ethanol fuel cells
    A group from Brazil and an HZB team have investigated a novel composite membrane for ethanol fuel cells. It consists of the polymer Nafion, in which nanoparticles of a titanium compound are embedded by the rarely explored melt extrusion process. At BESSY II they were able to observe in detail, how the nanoparticles in the Nafion matrix are distributed and how they contribute to increase proton conductivity.
  • New interaction between light and matter discovered at BESSY II
    Science Highlight
    23.04.2020
    New interaction between light and matter discovered at BESSY II
    A German-Chinese team led by Gisela Schütz from the MPI for Intelligent Systems has discovered a new interaction between light and matter at BESSY II. They succeeded in creating nanometer-fine magnetic vortices in a magnetic layer. These are so-called skyrmions, and candidates for future information technologies.
  • Tandem solar cell world record: New branch in the NREL chart
    Science Highlight
    14.04.2020
    Tandem solar cell world record: New branch in the NREL chart
    A special branch in the famous NREL-chart for solar cell world records refers to a newly developed tandem solar cell by HZB teams. The world-record cell combines the semiconductors perovskite and CIGS to a monolithic "two-terminal" tandem cell. Due to the thin-film technologies used, such tandem cells survive much longer in space and can even be produced on flexible films. The new tandem cell achieves a certified efficiency of 24.16 percent.
  • Neutron research: Magnetic monopoles detected in Kagome spin ice systems
    Science Highlight
    07.04.2020
    Neutron research: Magnetic monopoles detected in Kagome spin ice systems
    Magnetic monopoles are actually impossible. At low temperatures, however, certain crystals can contain so-called quasi-particles that behave like magnetic monopoles. Now an international cooperation has proven that such monopoles also occur in a Kagome spin ice system. Decisive factors were, among others, measurements with inelastic neutron scattering at the NEAT instrument of the Berlin neutron source BER II*. The results have been published in the journal Science.
  • Condensed Matter Physics: Long-standing prediction of quantum physics experimentally proven
    Science Highlight
    06.04.2020
    Condensed Matter Physics: Long-standing prediction of quantum physics experimentally proven
    90 years ago, the physicist Hans Bethe postulated that unusual patterns, so-called Bethe strings, appear in certain magnetic solids. Now an international team has succeeded in experimentally detecting such Bethe strings for the first time. They used neutron scattering experiments at various neutron facilities including the unique high-field magnet of BER II* at HZB. The experimental data are in excellent agreement with the theoretical prediction of Bethe and prove once again the power of quantum physics.
  • BESSY II: Ultra-fast switching of helicity of circularly polarized light pulses
    Science Highlight
    01.04.2020
    BESSY II: Ultra-fast switching of helicity of circularly polarized light pulses
    At the BESSY II storage ring, a joint team of accelerator physicists, undulator experts and experimenters has shown how the helicity of circularly polarized synchrotron radiation can be switched faster - up to a million times faster than before. They used an elliptical double-undulator developed at HZB and operated the storage ring in the so-called two-orbit mode. This is a special mode of operation that was only recently developed at BESSY II and provides the basis for fast switching. The ultra-fast change of light helicity is particularly interesting to observe processes in magnetic materials and has long been expected by a large user community.
  • Coronavirus SARS-CoV2: BESSY II data accelerate drug development
    Science Highlight
    19.03.2020
    Coronavirus SARS-CoV2: BESSY II data accelerate drug development
    A coronavirus is keeping the world in suspense. SARS-CoV-2 is highly infectious and can cause severe pneumonia with respiratory distress (COVID-19). Scientists are doing research in order to prevent the viruses from multiplying. A team from the University of Lübeck and from Helmholtz Centre for Infection Research (HZI) has now found a promising approach. Using the high-intensity X-ray light from the Berlin synchrotron source BESSY II, they have decoded the three-dimensional architecture of the main protease of SARS-CoV-2. This protein is involved in the reproduction of the virus. Analysing its 3D architecture allows the systematic development of drugs which inhibit the reproduction of the virus.
  • Fast and furious: New class of 2D materials stores electrical energy
    Science Highlight
    02.03.2020
    Fast and furious: New class of 2D materials stores electrical energy
    Two dimensional titanium carbides, so-called MXenes, are being discussed as candidates for the rapid storage of electrical energy. Like a battery,MXenes can store large amounts of electrical energy through electrochemical reactions- but unlike batteries,can be charged and discharged in a matter of seconds. In collaboration with Drexel University, a team at HZB showed that the intercalation of urea molecules between the MXene layers can increase the capacity of such "pseudo-capacitors" by more than 50 percent. At BESSY II they have analysed how changes of the MXene surface chemistry after urea intercalation are responsible for this.
  • X-ray microscopy at BESSY II: Nanoparticles can change cells
    Science Highlight
    12.02.2020
    X-ray microscopy at BESSY II: Nanoparticles can change cells
    Nanoparticles easily enter into cells. New insights about how they are distributed and what they do there are shown for the first time by high-resolution 3D microscopy images from the lightsources BESSY II and ALBA. For example, certain nanoparticles accumulate preferentially in certain organelles of the cell. This can increase the energy costs in the cell. "The cell looks like it has just run a marathon, apparently, the cell requires energy to absorb such nanoparticles" says lead author James McNally.
  • Not everything is ferromagnetic in high magnetic fields
    Science Highlight
    10.02.2020
    Not everything is ferromagnetic in high magnetic fields
    High magnetic fields have a potential to modify the microscopic arrangement of magnetic moments because they overcome interactions existing in zero field. Usually, high fields exceeding a certain critical value force the moments to align in the same direction as the field leading to ferromagnetic arrangement. However, a recent study showed that this is not always the case. The experiments took place at the high-field magnet at HZB's neutron source BER II, which generates a constant magnetic field of up to 26 Tesla. This is about 500,000 times stronger than the Earth's magnetic field. Further experiments with pulsed magnetic fields up to 45 Tesla were performed at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR). 
  • Battery research: Using neutrons and X-rays to analyse the ageing of lithium batteries
    Science Highlight
    07.02.2020
    Battery research: Using neutrons and X-rays to analyse the ageing of lithium batteries
    An international team has used neutron and X-ray tomography to investigate the dynamic processes that lead to capacity degradation at the electrodes in lithium batteries. Using a new mathematical method, it was possible to virtually unwind electrodes that had been wound into the form of a compact cylinder, and thus actually observe the processes on the surfaces of the electrodes. The study was published in Nature Communications.
  • Perovskite solar cells: International consensus on ageing measurement protocols
    Science Highlight
    31.01.2020
    Perovskite solar cells: International consensus on ageing measurement protocols
    Experts from 51 research institutions have now agreed on the procedures for measuring the stability of perovskite solar cells and assessing their quality. The consensus statement was published in Nature Energy and is considered a milestone for the further development of this new type of solar cell on its way to industrial application.
  • World Record: Efficiency of perovskite silicon tandem solar cell jumps to 29.15 per cent
    Science Highlight
    29.01.2020
    World Record: Efficiency of perovskite silicon tandem solar cell jumps to 29.15 per cent
    In the race for ever higher efficiency levels, an HZB development team has once again pulled ahead. The groups of Steve Albrecht and Bernd Stannowski have developed a tandem solar cell made of the semiconductors perovskite and silicon, that converts 29.15 per cent of the incident light into electrical energy. This value has been officially certified by the CalLab of the Fraunhofer Institute for Solar Energy Systems (ISE) and means that surpassing the 30 per cent efficiency mark is now within reach.
  • Plants absorb lead from perovskite solar cells more than expected
    Science Highlight
    21.01.2020
    Plants absorb lead from perovskite solar cells more than expected
    Lead from metal-organic perovskite compounds can be absorbed particularly easily by plants. The bioavailability is significantly higher than that of lead from inorganic compounds as found in batteries. This is shown in a study by HZB researcher Antonio Abate with partners in China and Italy, published in Nature communications.
  • Watching complex molecules at work
    Science Highlight
    14.01.2020
    Watching complex molecules at work
    A new method of infrared spectroscopy developed at BESSY II makes single-measurement observation and analysis of very fast as well as irreversible reaction mechanisms in molecules feasible for the first time. Previously, thousands of such reactions have had to be run and measured for this purpose. The research team has now used the new device to investigate how rhodopsin molecules change after activation by light – a process that is the basis of how we see.
  • Topological materials for information technology offer lossless transmission of signals
    Science Highlight
    18.12.2019
    Topological materials for information technology offer lossless transmission of signals
    New experiments with magnetically doped topological insulators at BESSY II have revealed possible ways of lossless signal transmission that involve a surprising self-organisation phenomenon. In the future, it might be possible to develop materials that display this phenomenon at room temperature and can be used as processing units in a quantum computer, for example. The study has been published in the renowned journal Nature.
  • Cancer research at BESSY II: Binding Mechanisms of Therapeutic Substances Deciphered
    Science Highlight
    12.12.2019
    Cancer research at BESSY II: Binding Mechanisms of Therapeutic Substances Deciphered
    In tumor cells, the DNA is altered in comparison to normal body cells. How such changes can be prevented or inhibited is an exciting field of research with great relevance for the development of cancer treatments. An interdisciplinary team has now analysed the possible binding mechanisms in certain therapeutic substances from the tetrazole hydrazide group using protein crystallography at BESSY II.
  • Perovskite solar cells: Possible aspects of high efficiency uncovered
    Science Highlight
    13.11.2019
    Perovskite solar cells: Possible aspects of high efficiency uncovered
    Using crystallographic analyses at the Diamond Light Source (DLS) synchrotron in the United Kingdom, an HZB team has demonstrated that hybrid halide perovskites crystallise without inversion centre. Interactions between the organic molecules and adjacent iodine atoms can lead to the formation of ferroelectric domains, which, indirectly, can result in higher solar-cell efficiencies. The formation of these ferroelectric domains cannot occur in purely inorganic perovskites.
  • X-ray microscopy at BESSY II reveals how antimalaria-drugs might work
    Science Highlight
    30.10.2019
    X-ray microscopy at BESSY II reveals how antimalaria-drugs might work
    Malaria is one of the most threatening infectious diseases in the world. An international team has now been able to investigate malaria pathogens in red blood cells in vivo using the BESSY II X-ray microscope and the ALBA and ESRF synchrotron sources. The scientists reveal the mechanisms used by active substances to attack the pathogen. This could contribute to improve treatment strategies and drug design.
  • Dynamic pattern of Skyrmions observed
    Science Highlight
    15.10.2019
    Dynamic pattern of Skyrmions observed
    Tiny magnetic vortices known as skyrmions form in certain magnetic materials, such as Cu2OSeO3. These skyrmions can be controlled by low-level electrical currents – which could facilitate more energy-efficient data processing. Now a team has succeeded in developing a new technique at the VEKMAG station of BESSY II for precisely measuring these vortices and observing their three different predicted characteristic oscillation modes (Eigen modes).
  • Faster than ever - neutron tomography detects water uptake by roots
    Science Highlight
    25.09.2019
    Faster than ever - neutron tomography detects water uptake by roots
    A team of researchers from Potsdam, Berlin and Grenoble was able to visualize the transport of water in soil as well as through roots of lupine plants using ultrafast 3D neutron imaging. The high-speed neutron tomography developed at HZB generates a complete 3D image every 1.5 seconds and is thus seven times faster than before. The method facilitates a better understanding of water and nutrient uptake of crop plants. The measurements were performed at the neutron source of the Laue Langevin Institute (ILL) in Grenoble, France. The method can also be applied to investigate transport processes in various porous material systems.
  • New sample holder for protein crystallography
    Science Highlight
    16.09.2019
    New sample holder for protein crystallography
    An HZB research team has developed a novel sample holder that considerably facilitates the preparation of protein crystals for structural analysis. A short video by the team shows how proteins in solution can be crystallised directly onto the new sample holders themselves, then analysed using the MX beamlines at BESSY II. A patent has already been granted and a manufacturer found.
  • World record for tandem perovskite-CIGS solar cell
    Science Highlight
    09.09.2019
    World record for tandem perovskite-CIGS solar cell
    A team headed by Prof. Steve Albrecht from the HZB will present a new world-record tandem solar cell at EU PVSEC, the world's largest international photovoltaic and solar energy conference and exhibition, in Marseille, France on September 11, 2019. This tandem solar cell combines the semiconducting materials perovskite and CIGS and achieves a certified efficiency of 23.26 per cent. One reason for this success lies in the cell’s intermediate layer of organic molecules: they self-organise to cover even rough semiconductor surfaces. Two patents have been filed for these layers.
  • Nanoparticles in lithium-sulphur batteries detected with neutron experiment
    Science Highlight
    06.09.2019
    Nanoparticles in lithium-sulphur batteries detected with neutron experiment
    An HZB team has for the first time precisely analysed how nanoparticles of lithium sulphide and sulphur precipitate onto battery electrodes during the course of the charging cycle. The results can help increase the service life of lithium-sulphur batteries.
  • Save time using maths: analytical tool designs corkscrew-shaped nano-antennae
    Science Highlight
    23.08.2019
    Save time using maths: analytical tool designs corkscrew-shaped nano-antennae
    For the first time, an HZB team has derived analytically how corkscrew-shaped nano-antennas interact with light. The mathematical tool can be used to calculate the geometry that a nano-antenna must have for specific applications in sensor technology or information technology.
  • World record in tomography: Watching how metal foam forms
    Science Highlight
    21.08.2019
    World record in tomography: Watching how metal foam forms
    An international research team at the Swiss Light Source (SLS) has set a new tomography world record using a rotary sample table developed at the HZB. With 208 three-dimensional tomographic X-ray images per second, they were able to document the dynamic processes involved in the foaming of liquid aluminium. The method is presented in the journal Nature Communications.
  • Archaeology at BESSY II: “Invisible ink” on antique Nile papyrus revealed
    Science Highlight
    14.08.2019
    Archaeology at BESSY II: “Invisible ink” on antique Nile papyrus revealed
    Researchers from the Egyptian Museum and Papyrus Collection, Berlin universities and Helmholtz-Zentrum Berlin studied a small piece of papyrus that was excavated on the island of Elephantine on the River Nile a little over 100 years ago. The team used serval methods including non-destructive techniques at BESSY II. The researchers’ work, reported in the Journal of Cultural Heritage, blazes a trail for further analyses of the papyrus collection in Berlin.
  • Accelerator physics: alternative material investigated for superconducting radio-frequency cavity resonators
    Science Highlight
    15.07.2019
    Accelerator physics: alternative material investigated for superconducting radio-frequency cavity resonators
    In modern synchrotron sources and free-electron lasers, superconducting radio-frequency cavity resonators are able to supply electron bunches with extremely high energy. These resonators are currently constructed of pure niobium. Now an international collaboration has investigated the potential advantages a niobium-tin coating might offer in comparison to pure niobium.
  • Oldest completely preserved lily discovered
    Science Highlight
    10.07.2019
    Oldest completely preserved lily discovered
    Already 115 million years ago, tropical flowering plants were apparently very diverse and showed all typical characteristics. This is the conclusion of an international team of researchers led by Clément Coiffard, Museum für Naturkunde Berlin. The team reported in the renowned journal Nature Plants on the oldest completely preserved lily, Cratolirion bognerianum, which was discovered at a site in present-day Brazil. With the help of 3D computer tomography at the Helmholtz-Zentrum Berlin, details on the back of the fossilised plant could also be analysed. The results raise new questions about the role of the tropics in the development of past and present ecosystems.
  • Charge transfer within transition-metal dyes analysed
    Science Highlight
    09.07.2019
    Charge transfer within transition-metal dyes analysed
    Transition-metal complexes in dye-based solar cells are responsible for converting light into electrical energy. A model of spatial charge separation within the molecule has been used to describe this conversion. However, an analysis at BESSY II shows that this description of the process is too simple. For the first time, a team there has investigated the fundamental photochemical processes around the metal atom and its ligands. The study has now been published in “Angewandte Chemie, international Edition” and is displayed on the cover.
  • Utrafast magnetism: electron-phonon interactions examined at BESSY II
    Science Highlight
    28.06.2019
    Utrafast magnetism: electron-phonon interactions examined at BESSY II
    How fast can a magnet switch its orientation and what are the microscopic mechanisms at play ? These questions are of first importance for the development of data storage and computer chips. Now, an HZB team at BESSY II has for the first time been able to experimentally assess the principal microscopic process of ultra-fast magnetism. The methodology developed for this purpose can also be used to investigate interactions between spins and lattice oscillations in graphene, superconductors or other (quantum) materials.
  • Organic electronics: a new semiconductor in the carbon-nitride family
    Science Highlight
    05.06.2019
    Organic electronics: a new semiconductor in the carbon-nitride family
    Teams from Humboldt-Universität and the Helmholtz-Zentrum Berlin have explored a new material in the carbon-nitride family. Triazine-based graphitic carbon nitride (TGCN) is a semiconductor that should be highly suitable for applications in optoelectronics. Its structure is two-dimensional and reminiscent of graphene. Unlike graphene, however, the conductivity in the direction perpendicular to its 2D planes is 65 times higher than along the planes themselves.
  • Laser-driven Spin Dynamics in Ferrimagnets: How does the Angular Momentum flow?
    Science Highlight
    10.05.2019
    Laser-driven Spin Dynamics in Ferrimagnets: How does the Angular Momentum flow?
    When exposed to intense laser pulses, the magnetization of a material can be manipulated very fast. Fundamentally, magnetization is connected to the angular momentum of the electrons in the material. A team of researchers led by scientists from the Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy (MBI) has now been able to follow the flow of angular momentum during ultrafast optical demagnetization in a ferrimagnetic iron-gadolinium alloy at the femtoslicing facility of BESSY II. Their results are helpful to understand the fundamental processes and their speed limits. The study is published in Physical Review Letters.
  • Copper oxide photocathodes: laser experiment reveals location of efficiency loss
    Science Highlight
    09.05.2019
    Copper oxide photocathodes: laser experiment reveals location of efficiency loss
    Solar cells and photocathodes made of copper oxide might in theory attain high efficiencies for solar energy conversion. In practice, however, large losses occur. Now a team at the HZB has been able to use a sophisticated femtosecond laser experiment to determine where these losses take place: not so much at the interfaces, but instead far more in the interior of the crystalline material. These results provide indications on how to improve copper oxide and other metal oxides for applications as energy materials.
  • 3D tomographic imagery reveals how lithium batteries age
    Science Highlight
    06.05.2019
    3D tomographic imagery reveals how lithium batteries age
    Lithium batteries lose amp-hour capacity over time. Microstructures can form on the electrodes with each new charge cycle, which further reduces battery capacity. Now an HZB team together with battery researchers from Forschungszentrum Jülich, the University of Munster, and partners in China have documented the degradation process of lithium electrodes in detail for the first time. They achieved this with the aid of a 3D tomography process using synchrotron radiation at BESSY II (HZB) as well at the Helmholtz-Zentrum Geesthacht (HZG). Their results have been published open access in the scientific journal "Materials Today".
  • Inorganic perovskite absorbers for use in thin-film solar cells
    Science Highlight
    29.04.2019
    Inorganic perovskite absorbers for use in thin-film solar cells
    A team at the Helmholtz-Zentrum Berlin has succeeded in producing inorganic perovskite thin films at moderate temperatures using co-evaporation – making post-tempering at high temperatures unnecessary. The process makes it much easier to produce thin-film solar cells from this material. In comparison to metal-organic hybrid perovskites, inorganic perovskites are more thermally stable. The work has been published in Advanced Energy Materials.
  • High-efficiency thermoelectric materials: new insights into tin selenide
    Science Highlight
    24.04.2019
    High-efficiency thermoelectric materials: new insights into tin selenide
    Tin selenide might considerably exceed the efficiency of current record holding thermoelectric materials made of bismuth telluride. However, it was thought its efficiency became enormous only at temperatures above 500 degrees Celsius. Now measurements at the BESSY II and PETRA III synchrotron sources show that tin selenide can also be utilised as a thermoelectric material at room temperature – so long as high pressure is applied.
  • "Molecular scissors" for plastic waste
    Science Highlight
    12.04.2019
    "Molecular scissors" for plastic waste
    A research team from the University of Greifswald and Helmholtz-Zentrum-Berlin (HZB) has solved the molecular structure of the important enzyme MHETase at BESSY II. MHETase was discovered in bacteria and together with a second enzyme - PETase - is able to break down the widely used plastic PET into its basic building blocks. This 3D structure already allowed the researchers to produce a MHETase variant with optimized activity in order to use it, together with PETase, for a sustainable recycling of PET. The results have been published in the research journal Nature Communications.
  • Catalyst research for solar fuels: Amorphous molybdenum sulphide works best
    Science Highlight
    04.04.2019
    Catalyst research for solar fuels: Amorphous molybdenum sulphide works best
    Efficient and inexpensive catalysts will be required for production of hydrogen from sunlight. Molybdenum sulphides are considered good candidates. A team at HZB has now explained what processes take place in molybdenum sulphides during catalysis and why amorphous molybdenum sulphide works best. The results have been published in the journal ACS Catalysis.
  • HZB contributions to special edition on Ultrafast Dynamics with X-ray Methods
    Science Highlight
    02.04.2019
    HZB contributions to special edition on Ultrafast Dynamics with X-ray Methods
    In the new special issue of the "Philosophical Transactions of the Royal Society of London", internationally renowned experts report on new developments in X-ray sources and ultrafast time-resolved experiments. HZB physicists have also been invited to contribute.
  • X-ray analysis of carbon nanostructures helps material design
    Science Highlight
    13.03.2019
    X-ray analysis of carbon nanostructures helps material design
    Nanostructures made of carbon are extremely versatile: they can absorb ions in batteries and supercapacitors, store gases, and desalinate water. How well they cope with the task at hand depends largely on the structural features of the nanopores. A new study from the HZB has now shown that structural changes that occur due to morphology transition with increasing temperature of the synthesis can also be measured directly – using small-angle X-ray scattering. The results have now been published in the journal Carbon.
  • Water is more homogeneous than expected
    Science Highlight
    20.02.2019
    Water is more homogeneous than expected
    In order to explain the known anomalies in water, some researchers assume that water consists of a mixture of two phases even under ambient conditions. However, new X-ray spectroscopic analyses at BESSY II, ESRF and Swiss Light Source show that this is not the case. At room temperature and normal pressure, the water molecules form a fluctuating network with an average of 1.74 ± 2.1% donor and acceptor hydrogen bridge bonds per molecule each, allowing tetrahedral coordination between close neighbours.
  • Spintronics by “straintronics”: Superferromagnetism with electric-field induced strain
    Science Highlight
    14.02.2019
    Spintronics by “straintronics”: Superferromagnetism with electric-field induced strain
    Data storage in today’s magnetic media is very energy consuming. Combination of novel materials and the coupling between their properties could reduce the energy needed to control magnetic memories thus contributing to a smaller carbon footprint of the IT sector. Now an international team led by HZB has observed at the HZB lightsource BESSY II a new phenomenon in iron nanograins: whereas normally the magnetic moments of the iron grains are disordered with respect each other at room temperature, this can be changed by applying an electric field: This field induces locally a strain on the system leading to the formation of a so-called superferromagnetic ordered state.
  • Ultra-thin and extremely efficient: Thin-film tandem cells made of perovskite and CIGSe semiconductors
    Science Highlight
    31.01.2019
    Ultra-thin and extremely efficient: Thin-film tandem cells made of perovskite and CIGSe semiconductors
    An HZB team has fabricated and characterised a thin-film tandem solar cell made of perovskite and CIGSe. They relied on a simple, robust fabrication process that is also suitable for scaling up to large surface areas. The tandem solar cell is a fully thin film device with an impressive efficiency of 21.6 %. With further improvements it might reach efficiencies above 30 %.
  • Batteries with silicon anodes: Neutron experiments show how formation of surface structures reduces amp-hour capacity
    Science Highlight
    28.01.2019
    Batteries with silicon anodes: Neutron experiments show how formation of surface structures reduces amp-hour capacity
    In theory, silicon anodes could store ten times more lithium ions than graphite anodes, which have been used in commercial lithium batteries for many years. However, the amp-hour capacity of silicon anodes so far has been declining sharply with each additional charge-discharge cycle. Now an HZB team at BER II of the HZB in Berlin and the Institut Laue-Langevin in Grenoble has utilised neutron experiments to establish what happens at the surface of the silicon anode during charging and what processes reduce this capacity.
  • Climate change: How could artificial photosynthesis contribute to limiting global warming?
    Science Highlight
    16.01.2019
    Climate change: How could artificial photosynthesis contribute to limiting global warming?

    If CO2 emissions do not fall fast enough, then CO2 will have to be removed from the atmosphere in the future to limit global warming. Not only could planting new forests and biomass contribute to this, but new technologies for artificial photosynthesis as well. An HZB physicist and a researcher at the University of Heidelberg have estimated how much surface area such solutions would require. Although artificial photosynthesis could bind CO2 more efficiently than the natural model, there are still no large modules that are stable over the long term. The team published their calculations in "Earth System Dynamics".

  • Neutronenforschung hilft bei der Entwicklung von zerstörungsfreien Prüfverfahren
    Science Highlight
    21.12.2018
    Neutronenforschung hilft bei der Entwicklung von zerstörungsfreien Prüfverfahren
    Materialermüdung zeigt sich häufig zuerst daran, dass im Innern des Materials Bereiche mit stark unterschiedlichen Eigenspannungen aneinandergrenzen. An der Neutronenquelle BER II am HZB hat ein Team der Bundesanstalt für Materialforschung und –prüfung (BAM) die Eigenspannungen von Schweißnähten aus ferromagnetischem Stahl analysiert. Die Ergebnisse helfen zerstörungsfreie elektromagnetische Prüfverfahren zu verbessern.
  • Milestone for bERLinPro: photocathodes with high quantum efficiency
    Science Highlight
    07.12.2018
    Milestone for bERLinPro: photocathodes with high quantum efficiency
    A team at the HZB has improved the manufacturing process of photocathodes and can now provide photocathodes with high quantum efficiency for bERLinPro.
  • Molecules that self-assemble into monolayers for efficient perovskite solar cells
    Science Highlight
    23.11.2018
    Molecules that self-assemble into monolayers for efficient perovskite solar cells
    A team at the HZB has discovered a new method for producing efficient contact layers in perovskite solar cells. It is based on molecules that organise themselves into a monolayer. The study was published in Advanced Energy Materials and appeared on the front cover of the journal.
  • Transition metal complexes: mixed works better
    Science Highlight
    14.11.2018
    Transition metal complexes: mixed works better
    A team at BESSY II has investigated how various iron-complex compounds process energy from incident light. They were able to show why certain compounds have the potential to convert light into electrical energy. The results are important for the development of organic solar cells. The study has now been published in the journal PCCP, and its illustration selected for the cover.
  • New records in perovskite-silicon tandem solar cells through improved light management
    Science Highlight
    12.11.2018
    New records in perovskite-silicon tandem solar cells through improved light management
    Using microstructured layers, an HZB team has been able to increase the efficiency of perovskite-silicon tandem solar cells, achieving 25.5 %, which is the highest published value to date. At the same time, computational simulations were utilized to investigate light conversion in various device designs with different nanostructured surfaces. This enabled optimization of light management and detailed energy yield analyses. The study has now been published in Energy & Environmental Science.
  • Graphene on the way to superconductivity
    Science Highlight
    10.11.2018
    Graphene on the way to superconductivity
    Scientists at HZB have found evidence that double layers of graphene have a property that may let them conduct current completely without resistance. They probed the bandstructure at BESSY II with extremely high resolution ARPES and could identify a flat area at a surprising location.
  • Nanodiamonds as photocatalysts
    Science Highlight
    18.10.2018
    Nanodiamonds as photocatalysts
    Diamond nanomaterials are considered hot candidates for low-cost photocatalysts. They can be activated by light and can then accelerate certain reactions between water and CO2 and produce carbon-neutral "solar fuels". The EU project DIACAT has now doped such diamond materials with boron and shown at BESSY II how this could significantly improve the photocatalytic properties.
  • Blue phosphorus - mapped and measured for the first time
    Science Highlight
    15.10.2018
    Blue phosphorus - mapped and measured for the first time
    Until recently, the existence of "blue" phosphorus was pure theory: Now an HZB team was able to examine samples of blue phosphorus at BESSY II for the first time and confirm via mapping of their electronic band structure that this is actually this exotic phosphorus modification. Blue phosphorus is an interesting candidate for new optoelectronic devices. The results have been published in Nano Letters.
  • Neutrons scan magnetic fields inside samples
    Science Highlight
    02.10.2018
    Neutrons scan magnetic fields inside samples
    With a newly developed neutron tomography technique, an HZB team has been able to map for the first time magnetic field lines inside materials at the BER II research reactor. Tensorial neutron tomography promises new insights into superconductors, battery electrodes, and other energy-related materials.
  • HZB researchers boost the efficiency of silicon solar cells
    Science Highlight
    02.10.2018
    HZB researchers boost the efficiency of silicon solar cells
    The efficiency of a solar cell is one of its most important parameters. It indicates what percentage of the solar energy radiated into the cell is converted into electrical energy. The theoretical limit for silicon solar cells is 29.3 percent due to physical material properties. In the journal Materials Horizons, researchers from Helmholtz-Zentrum Berlin (HZB) and international colleagues describe how this limit can be abolished. The trick: they incorporate layers of organic molecules into the solar cell. These layers utilise a quantum mechanical process known as singlet exciton fission to split certain energetic light (green and blue photons) in such a way that the electrical current of the solar cell can double in that energy range.
  • Machine learning helps improving photonic applications
    Science Highlight
    28.09.2018
    Machine learning helps improving photonic applications
    Photonic nanostructures can be used for many applications, not just in solar cells, but also in optical sensors for cancer markers or other biomolecules, for example. A team at HZB using computer simulations and machine learning has now shown how the design of such nanostructures can be selectively optimised. The results are published in Communications Physics.
  • Newsletter and Highlightreport
    Science Highlight
    24.09.2018
    Newsletter and Highlightreport
    Exactly twenty years ago, BESSY II went into operation. In the current September newsletter, which we are sending out this week, we present the anniversary website, report on the new highlight report 2017 and on successes in technology transfer. Have you already registered for the newsletter? Here is the registration link.
  • Patented nanostructure for solar cells: Rough optics, smooth surface
    Science Highlight
    17.09.2018
    Patented nanostructure for solar cells: Rough optics, smooth surface
    Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.
  • Future information technologies: nanoscale heat transport under the microscope
    Science Highlight
    21.08.2018
    Future information technologies: nanoscale heat transport under the microscope
    A team of researchers from the Helmholtz-Zentrum Berlin (HZB) and the University of Potsdam has investigated heat transport in a model system comprising nanometre-thin metallic and magnetic layers. Similar systems are candidates for future high-efficiency data storage devices that can be locally heated and rewritten by laser pulses (Heat-Assisted Magnetic Recording). Measurements taken with extremely short X-ray pulses have now shown that the heat is distributed a hundred times slower than expected in the model system. The results are published in Nature Communications.
  • World record: Fastest 3D tomographic images at BESSY II
    Science Highlight
    08.08.2018
    World record: Fastest 3D tomographic images at BESSY II
    An HZB team has developed an ingenious precision rotary table at the EDDI beamline at BESSY II and combined it with particularly fast optics. This enabled them to document the formation of pores in grains of metal during foaming processes at 25 tomographic images per second - a world record.
  • Insight into loss processes in perovskite solar cells enables efficiency improvements
    Science Highlight
    01.08.2018
    Insight into loss processes in perovskite solar cells enables efficiency improvements
    In perovskite solar cells, charge carriers are mainly lost through recombination occurring at interface defect sites. In contrast, recombination at defect sites within the perovskite layer does not limit the performance of the solar cells at present. Teams from the University of Potsdam and the Helmholtz-Zentrum Berlin (HZB) were able to reach this interesting conclusion through extremely accurate quantitative measurements on 1 cm2 perovskite cells using photoluminescence. Their results contribute to improving  perovskite solar cells and have now been published in Nature Energy.
  • Insight into catalysis through novel study of X-ray absorption spectroscopy
    Science Highlight
    31.07.2018
    Insight into catalysis through novel study of X-ray absorption spectroscopy
    An international team has made a breakthrough at BESSY II. For the first time, they succeeded in investigating electronic states of a transition metal in detail and drawing reliable conclusions on their catalytic effect from the data. These results are helpful for the development of future applications of catalytic transition-metal systems. The work has now been published in Chemical Science, the Open Access journal of the Royal Society of Chemistry.
  • Wissenstransfer: Neues Standardwerk zu Energietechnologien in Deutschland
    Science Highlight
    26.07.2018
    Wissenstransfer: Neues Standardwerk zu Energietechnologien in Deutschland
    Vertreter des Wuppertal Instituts haben dem Bundesministerium für Wirtschaft und Energie (BMWi) einen mehrbändigen Bericht zu Energietechnologien übergeben. Dabei haben Experten aus dem HZB-Institut PVcomB am Themenfeld Photovoltaik mitgewirkt. Im Herbst verabschiedet die Bundesregierung das neue 7. Energieforschungsprogramm (EFP). Der Bericht liefert eine wissenschaftliche Basis für die Entwicklung des Programms.
  • Future information technology: Microscopic insight into processes when magnets suddenly heat up
    Science Highlight
    16.07.2018
    Future information technology: Microscopic insight into processes when magnets suddenly heat up
    Magnetic solids can demagnetize upon heating. Despite decades of research, it has so far been unclear how this process works in detail. Now, for the first time, an international group has observed in a step-by-step manner how sudden heating affects the magnetic order of a ferrimagnetic insulator. The result: The magnetic order changes on two time scales. The first process is surprisingly fast and takes only one picosecond, while the second process takes 100,000 times longer. This insight could help to increase the switching speed in magnetic storage media by at least a factor of 1000.  The work is published in Science Advances.
  • New world record for direct solar water-splitting efficiency
    Science Highlight
    05.07.2018
    New world record for direct solar water-splitting efficiency
    Hydrogen will play a central role as a storage medium in sustainable energy systems. An international team of researchers has now succeeded in raising the efficiency of producing hydrogen from direct solar water-splitting to a record 19 per cent. They did so by combining a tandem solar cell of III-V semiconductors with a catalyst of rhodium nanoparticles and a crystalline titanium dioxide coating. Teams from the California Institute of Technology, the University of Cambridge, Technische Universität Ilmenau, and the Fraunhofer Institute for Solar Energy Systems ISE participated in the development work. One part of the experiments took place at the Institute for Solar Fuels in the Helmholtz-Zentrum Berlin.
  • Silicon heterojunction solar cell with a certified 23.1 % energy conversion efficiency
    Science Highlight
    22.06.2018
    Silicon heterojunction solar cell with a certified 23.1 % energy conversion efficiency
    After further optimization of the baseline process for industrial silicon heterojunction (SHJ) solar cells, the accredited metrology lab ISFH CalTeC now certified an efficiency of 23.1 % for a 4 cm² solar cell. This performance is among the best in the world and demonstrates the leading role of HZB in this technology in Germany and Europe.
  • Perovskite-silicon solar cell research collaboration hits 25.2% efficiency
    Science Highlight
    14.06.2018
    Perovskite-silicon solar cell research collaboration hits 25.2% efficiency
    A 1 cm2 perovskite silicon tandem solar cell achieves an independently certified efficiency of 25.2 %. This was presented this week at an international conference in Hawaii, USA. The cell was developed jointly by HZB, Oxford University and Oxford PV - The Perovskite CompanyTM.
  • Neutron tomography: Insights into the interior of teeth, root balls, batteries, and fuel cells
    Science Highlight
    05.06.2018
    Neutron tomography: Insights into the interior of teeth, root balls, batteries, and fuel cells
    A team of researchers at Helmholtz-Zentrum Berlin (HZB) and European Spallation Source (ESS) has now published a comprehensive overview of neutron-based imaging processes in the renowned journal Materials Today (impact factor 21.6). The authors report on the latest developments in neutron tomography, illustrating the possible applications using examples of this non-destructive method. Neutron tomography has facilitated breakthroughs in so diverse areas such as art history, battery research, dentistry, energy materials, industrial research, magnetism, palaeobiology and plant physiology.
  • Helmholtz Virtual Institute MiCo: Article selected as journal highlight for 2017
    Science Highlight
    17.05.2018
    Helmholtz Virtual Institute MiCo: Article selected as journal highlight for 2017
    The Helmholtz Virtual Institute MiCo offers a platform through which the Helmholtz-Zentrum Berlin conducts joint research with universities and other partners on the topic of microstructures for thin-film solar cells. The journal Modelling and Simulation in Materials Science and Engineering recently selected an article produced through MiCo as the highlight of those published by the journal during 2017.
  • Writing and deleting magnets with lasers
    Science Highlight
    18.04.2018
    Writing and deleting magnets with lasers
    Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia in Charlottesville, USA have found a way to write and delete magnets in an alloy using a laser beam – a surprising effect. The reversibility of the process opens up new possibilities in the fields of material processing, optical technology, and data storage.
  • Kesterite solar cells: germanium promises better opto-electronic properties than tin
    Science Highlight
    29.03.2018
    Kesterite solar cells: germanium promises better opto-electronic properties than tin
    Specific changes in the composition of kesterite-type semiconductors make it possible to improve their suitability as absorber layers in solar cells. As a team at the Helmholtz-Zentrum Berlin showed, this is particularly true for kesterites in which tin was replaced by germanium. The scientists examined the samples using neutron diffraction at BER II and other methods. The work was selected for the cover of the journal CrystEngComm.
  • Twin Orbit operation successfully tested at BESSY II
    Science Highlight
    15.03.2018
    Twin Orbit operation successfully tested at BESSY II
    The first “Twin Orbit User Test week” at BESSY II in February 2018 was a big success and can be considered as an important step towards real user operation. Physicists at Helmholtz-Zentrum Berlin have been able to store two separate electron beams in one storage ring. The twin orbit operation mode can serve users with different needs of the time structure of the photon pulses simultaneously and offers elegant options regarding the future project BESSY VSR.
  • Solar–to-hydrogen conversion: nanostructuring increases efficiency of metal-free photocatalysts by factor eleven
    Science Highlight
    28.02.2018
    Solar–to-hydrogen conversion: nanostructuring increases efficiency of metal-free photocatalysts by factor eleven
    Polymeric carbon nitrides exhibit a catalytic effect in sunlight that can be used for the production of hydrogen from solar energy. However, the efficiency of these metal-free catalysts is extremely low. A team at the Tianjin University in China, in collaboration with a group at the Helmholtz-Zentrum Berlin, has increased the catalytic efficiency of these polymeric carbon nitrides by a factor eleven through a simple process resulting in a larger surface area. The paper was published in the journal Energy & Environmental Science.
  • Luminescent nano-architectures of gallium arsenide
    Science Highlight
    22.02.2018
    Luminescent nano-architectures of gallium arsenide
    A team at the HZB has succeeded in growing nanocrystals of gallium arsenide on tiny columns of silicon and germanium. This enables extremely efficient optoelectronic components for important frequency ranges to be realised on silicon chips.
  • Hidden talents: Converting heat into electricity with pencil and paper
    Science Highlight
    16.02.2018
    Hidden talents: Converting heat into electricity with pencil and paper
    Thermoelectric materials can use thermal differences to generate electricity. Now there is an inexpensive and environmentally friendly way of producing them with the simplest of components: a normal pencil, photocopy paper, and conductive paint are sufficient to convert a temperature difference into electricity via the thermoelectric effect. This has now been demonstrated by a team at the Helmholtz-Zentrum Berlin.
  • User research at BER II: New insights into high-temperature superconductors
    Science Highlight
    09.02.2018
    User research at BER II: New insights into high-temperature superconductors
    After 30 years of research, there are still many unsolved puzzles about high-temperature superconductors - among them is the magnetic “stripe order” found in some cuprate superconductors. A Danish research team has taken a closer look at these stripes, using high-resolution neutron scattering at the spectrometers FLEXX (HZB) and ThALES (ILL, Grenoble). Their results, now published in Physical Review Letters, challenge the common understanding of stripe order, and may contribute to unveil the true nature  of high-temperature superconductivity.
  • 40-year controversy in solid-state physics resolved
    Science Highlight
    06.02.2018
    40-year controversy in solid-state physics resolved
    An international team at BESSY II headed by Prof. Oliver Rader has shown that the puzzling properties of samarium hexaboride do not stem from the material being a topological insulator, as it had been proposed to be. Theoretical and initial experimental work had previously indicated that this material, which becomes a Kondo insulator at very low temperatures, also possessed the properties of a topological insulator. The team has now published a compelling alternative explanation in Nature Communications, however.
  • User experiment at BESSY II:  Complex tessellations, extraordinary materials
    Science Highlight
    23.01.2018
    User experiment at BESSY II: Complex tessellations, extraordinary materials
    Simple organic molecules form complex materials through self-organization
  • Perovskite solar cells: mesoporous interface mitigates the impact of defects
    Science Highlight
    18.01.2018
    Perovskite solar cells: mesoporous interface mitigates the impact of defects
    The nominal cell operating life of perovskite solar cells is strongly influenced by their inner architecture.This was shown by two scientists at the Helmholtz-Zentrum Berlin and the Technical University of Munich. They combined experiments with numerical simulations in order to explain this observation.
  • Perovskite solar cells: perfection not required!
    Science Highlight
    15.01.2018
    Perovskite solar cells: perfection not required!
    Experiments at BESSY II reveal why even inhomogeneous perovskite films are highly functional 
  • Solar energy: Defects in Kesterite semiconductors studied using neutrons
    Science Highlight
    07.12.2017
    Solar energy: Defects in Kesterite semiconductors studied using neutrons
    A research team at the HZB has precisely characterised for the first time the various types of defects in kesterite semiconductors. They achieved this with the help of neutron scattering at the BER II research reactor and at Oak Ridge National Laboratory in the USA. The findings point to a means of guided optimisation for kesterite solar cells.
  • Neutron spectroscopy: new detector module MultiFLEXX increases count rate tenfold
    Science Highlight
    01.12.2017
    Neutron spectroscopy: new detector module MultiFLEXX increases count rate tenfold
    The triple axis spectrometer FLEXX at BER II provides a new detector module for user service. It measures many angles and multiple energy transfers simultaneously and thus increases the amount of data measured per hour by about a factor of ten. This enables neutron users to make optimal use of their beam time.
  • Light facilitates “impossible“ n-doping of organic semiconductors
    Science Highlight
    23.11.2017
    Light facilitates “impossible“ n-doping of organic semiconductors
    Applications as light-emitting diodes and solar cells
  • Future IT: Antiferromagnetic dysprosium reveals magnetic switching with less energy
    Science Highlight
    06.11.2017
    Future IT: Antiferromagnetic dysprosium reveals magnetic switching with less energy
    HZB scientists have identified a mechanism with which it may be possible to develop a form of magnetic storage that is faster and more energy-efficient. They compared how different forms of magnetic ordering in the rare-earth metal named dysprosium react to a short laser pulse. They discovered that the magnetic orientation can be altered much faster and with considerably less energy if the magnetic moments of the individual atoms do not all point in the same direction (ferromagnetism), but instead point are rotated against each other (anti-ferromagnetism). The study was published in Physical Review letters on 6. November 2017 and on the cover of the print edition.
  • New magazine “lichtblick” is out: Select articles can be read in English on the website
    Science Highlight
    02.11.2017
    New magazine “lichtblick” is out: Select articles can be read in English on the website
    Some artikels from our magazine lichtblick are available in English: You can find these articles here: http://hz-b.de/lichtblick-en
  • High Field Magnet at BER II: Insight into a hidden order
    Science Highlight
    19.10.2017
    High Field Magnet at BER II: Insight into a hidden order
    A specific uranium compound has puzzled researchers for thirty years. Although the crystal structure is simple, no one understands exactly what is happening once it is cooled below a certain temperature. Apparently, a “hidden order” emerges,  whose nature is completely unknown.Now physicists have characterised this hidden order state more precisely and studied it on a microscopic scale. To accomplish this, they utilised the High-Field Magnet at the HZB that permits neutron experiments to be conducted under conditions of extremely high magnetic fields.
  • Missing link between new topological phases of matter discovered
    Science Highlight
    17.10.2017
    Missing link between new topological phases of matter discovered
    HZB-Physicists at BESSY II have investigated a class of materials that exhibit characteristics of topological insulators. During these studies they discovered a transition between two different topological phases, one of which is ferroelectric, meaning a phase in the material that exhibits spontaneous electric polarisation and can be reversed by an external electric field. This could also lead to new applications such as switching between differing conductivities.
  • Novel soft X-ray spectrometer enables individual steps of photosynthetic water oxidation to be observed
    Science Highlight
    30.09.2017
    Novel soft X-ray spectrometer enables individual steps of photosynthetic water oxidation to be observed
    HZB scientists have developed a novel spectrometer at BESSY II that enables researchers to obtain detailed insights about catalytic processes in metalloenzymes. Their international collaboration was successful in delineating individual steps in the catalytic oxidation of water to dioxygen in photosystem II. They published their study in the journal Structural Dynamics. Photosystem II is a part of the of photosynthetic electron transport chain, a process that is responsible for the conversion of solar energy to chemical energy in plants, algae and cyanobacteria.
  • The miracle material graphene: convex as a chesterfield
    Science Highlight
    18.09.2017
    The miracle material graphene: convex as a chesterfield
    Graphene possesses extreme properties and can be utilised in many ways. Even the spins of graphene can be controlled through use of a trick. This had already been demonstrated by a HZB team some time ago: the physicists applied a layer of graphene onto a nickel substrate and introduced atoms of gold in between (intercalation). The scientists now show why this has such a dramatic influence on the spins in a paper published in 2D Materials. As a result, graphene can also be considered as a material for future information technologies that are based on processing spins as units of information.
  • Solar hydrogen production by artificial leafs:
    Science Highlight
    28.08.2017
    Solar hydrogen production by artificial leafs:
    Scientists analysed how a special treatment improves cheap metal oxide photoelectrodes
  • Optical control of magnetic memory – new insights into fundamental mechanisms
    Science Highlight
    25.08.2017
    Optical control of magnetic memory – new insights into fundamental mechanisms
    A research team at Helmholtz-Zentrum Berlin (HZB) has shown for the first time how laser modulation of magnetic properties in materials is influenced by thermal effects and how the process occurs under moderate experimental parameters. At the same time, the scientists discovered a previously unknown dependence on the thickness of the magnetic layer. This is an important clue for our theoretical understanding of optically controlled magnetic data storage media. The findings are published today in the journal Scientific Reports.
  • New model for bimolecular reactions in nanoreactors
    Science Highlight
    04.08.2017
    New model for bimolecular reactions in nanoreactors
    Theoretical physicists have devised a mathematical model of two different molecules reacting within so called nanoreactors that act as catalysts. They gained surprising new insights as to what factors promote reactions and how to control and select them. The model is relevant for a wide range of research fields, from biophysics to energy materials.
  • User research at BER II: Lupin roots observed in the act of catching water from soil – so far too quick for 3D views
    Science Highlight
    25.07.2017
    User research at BER II: Lupin roots observed in the act of catching water from soil – so far too quick for 3D views
    Lupins not only produce colourful blossoms but also nutritious beans rich in proteins. Just how these plants draw water approaching their roots in soil has now for the first time been observed in three dimensions by a University of Potsdam team at the HZB-BER II neutron source in Berlin. To accomplish this, they worked with the HZB imaging group to improve the temporal resolution of neutron tomography more than onehundred-fold so that a detailed 3D image was generated every ten seconds. This ultrafast neutron tomography is generally suitable as well for analyses of dynamic processes in porous materials.
  • Writing with the electron beam: now in silver
    Science Highlight
    24.07.2017
    Writing with the electron beam: now in silver
    For the first time an international team realized direct writing of silver nanostructures using an electron beam applied to a substrate. Silver nanostructures have the potential to concentrate visible light at the nanoscale. Potential applications include sensor design to detect extremely small traces of specific molecules, as well as devices for optical information processing.
  • Modern, concise and informative: HZB presents itself
    Science Highlight
    19.07.2017
    Modern, concise and informative: HZB presents itself
    A information brochure, illustrated throughout with a fusion of photos and sketches, serves as the new business card of HZB. In concise and understandable language, it describes the centre’s most important research focuses, introduces the large-scale facilities and laboratories, and shows why HZB is an internationally attractive place to work.
  • HZB researcher receives university-level teaching credential (Habilitation)
    Science Highlight
    19.06.2017
    HZB researcher receives university-level teaching credential (Habilitation)
    Dr. Klaus Habicht has successfully completed the university-level teaching accreditation process in the Faculty of Mathematics and Natural Sciences at the University of Potsdam and received his official university-level teaching qualification for the physics of condensed matter. Habicht has conducted numerous lectures and seminars at the University of Potsdam since 2011, in particular in solid-state physics and methods in neutron research. He heads the Department of Methods for Characterisation of Transport Phenomenon in Energy Materials at the HZB.
  • HZB paper appears in special anniversary edition of the Journal of Physics D: Applied Physics
    Science Highlight
    01.06.2017
    HZB paper appears in special anniversary edition of the Journal of Physics D: Applied Physics
    A paper on X-ray tomography of various types of batteries has been published as a highlight in the exclusive special edition of the Journal of Physics D: Applied Physics. Two groups at the HZB along with a team from Justus Liebig University in Giessen, Germany, contributed to the article.
  • Trends and pathways to high-efficiency perovskite solar cells
    Science Highlight
    30.05.2017
    Trends and pathways to high-efficiency perovskite solar cells
    Perovskite  solar cells have been the big surprise over the last while: inside of only a few years, their efficiency level has been increased from just under 10 % to fully 22 %. There has never been such rapid progress in a new material for solar cells. Scientists around the world are therefore working on this new class of materials. Eva Unger and Steve Albrecht from Helmholtz-Zentrum Berlin (HZB) have evaluated trends in the advancement of perovskite materials in an invited review article in Journal of Materials Chemistry A. They point out what opportunities exist for advancing this class of materials, combining them with other semiconductors, and where limitations lie. 
  • Better cathode materials for Lithium-Sulphur-Batteries
    Science Highlight
    17.05.2017
    Better cathode materials for Lithium-Sulphur-Batteries
    A team at the Helmholtz-Zentrum Berlin (HZB) has for the first time fabricated a nanomaterial made from nanoparticles of a titanium oxide compound (Ti4O7) that is characterised by an extremely large surface area, and tested it as a cathode material in lithium-sulphur batteries. The highly porous nanomaterial possesses high storage capacity that remains nearly constant over many charging cycles.
  • Nanodiamonds as energy materials: tuning the functionalities
    Science Highlight
    26.04.2017
    Nanodiamonds as energy materials: tuning the functionalities
    An international team has shed light onto interactions between nanodiamonds and water molecules. Experiments at synchrotron sources showed how hydrogenated groups on nanodiamond surfaces change the network of hydrogen bonds in the aqueous environment and may potentially influence the catalytic properties of nanodiamonds, for instance for the production of solar fuels from CO2 and light.
  • Proton transfer: Researcher find mecanism to protect biomolecules against light induced damage
    Science Highlight
    07.04.2017
    Proton transfer: Researcher find mecanism to protect biomolecules against light induced damage
    A team at the Helmholtz-Zentrum Berlin (HZB) together with researchers in Sweden and the USA has analysed a mecanism which protects biomolecules such as the DNA against damage by light. They observed how the energy of incoming photons can be absorbed by the molecule without destroying important bonds. The experiments took place at the Linac Coherent Light Source (LCLS) free-electron laser in California as well as the BESSY II synchrotron source at the HZB in Berlin, where with resonant inelastic X-ray-diffraction a very sensitive method is available.
  • Finding and understanding low cost catalysts: it all comes down to the iron
    Science Highlight
    23.03.2017
    Finding and understanding low cost catalysts: it all comes down to the iron
    A team has investigated more than one hundred iron-nickel catalysts containing various admixtures of chromium. At BESSY II, they also analysed the configurations of the electrons in the individual elements. The team showed that an increasing proportion of chromium primarily influences the energy levels of the iron electrons, which are important for the catalytic effect. The results of this high-throughput study will assist the knowledge-based search for better specific catalysts.
  • How to increase efficiencies of ultrathin CIGSe solar cells
    Science Highlight
    14.03.2017
    How to increase efficiencies of ultrathin CIGSe solar cells
    Nanoparticles at the back help harvesting the light.
  • Highly sensitive method for detecting ion pairs in aqueous solution developed
    Science Highlight
    09.03.2017
    Highly sensitive method for detecting ion pairs in aqueous solution developed

    Scientists of the Helmholtz-Zentrum Berlin, Freie Universität Berlin, Universität Heidelberg, and the University of Chemistry and Technology Prague have empirically detected a very specialised type of electron transfer in an aqueous salt solution, one which had only been predicted theoretically up to now. Based on these results, they now expect to have an extremely sensitive method for detecting ion pairs in solutions.

  • Fuel cells with PFIA-membranes:
    Science Highlight
    19.12.2016
    Fuel cells with PFIA-membranes:
  • A new record at BESSY II: ten million ions in an ion trap cooled for the first time to 7.4 K
    Science Highlight
    28.11.2016
    A new record at BESSY II: ten million ions in an ion trap cooled for the first time to 7.4 K
    Magnetic ground states spectroscopically ascertained
  • Methods at BESSY II: Versatile cross-correlator for ultrafast X-ray experiments
    Science Highlight
    14.11.2016
    Methods at BESSY II: Versatile cross-correlator for ultrafast X-ray experiments
    Particularly in the soft X-ray range experimentalists are lacking a broadband method to correlate ultrashort X-ray and laser pulses in space and time. Only recently, a team from Helmholtz-Zentrum Berlin and the University of Potsdam was able to achieve this by utilizing a standard molybdenum-silicon (Mo/Si) multilayer mirror at the FemtoSpeX facility at BESSY II. They use femtosecond laser pulses to modulate the multilayer period under the Bragg condition on a sub-picosecond up to nanosecond timescale which in turn strongly affects the mirror’s X-ray reflectivity. The presented Mo/Si cross-correlator works for the soft up to the hard X-ray regime as well as for a broad range of laser pump wavelengths (mid-IR to UV) and renders this technique as an easy to implement and versatile timing tool for various synchrotron- and lab-based pump-probe experiments. The results are published in the journal of "Structural Dynamics".
  • Methodology advance at HZB: ionic liquids simplify laser experiments on liquid samples
    Science Highlight
    19.10.2016
    Methodology advance at HZB: ionic liquids simplify laser experiments on liquid samples
    An HZB team has developed a new approach to conduct photoemission spectroscopy of molecules in solution. This has been difficult up to now because the sample needed to be situated in vacuum – but liquids evaporate. The work has now demonstrated it is feasible to replace the solvent with an ionic liquid of low vapor pressure, which does not perturb the sample characteristics.  This allows the molecules to be excited with a laser pulse and to record the behaviour of the excited energy states. It provides insight into the physical and chemical processes of novel liquid energy materials that might be employed in organic solar cells or catalysts, for instance.
  • Future Information Technologies: New combinations of materials for producing magnetic monopoles
    Science Highlight
    10.10.2016
    Future Information Technologies: New combinations of materials for producing magnetic monopoles
    An international collaboration at BESSY II has discovered a new method to inscribe exotic magnetic patterns such as magnetic monopoles into thin ferromagnetic films. Such unconventional orientation of magnetic domains might open a new path for the design of energy efficient data storage. The new materials system consists of regular arrays of superconducting YBaCuO-dots covered with an extremely thin permalloy film. A shortly applied external magnetic field leads to the creation of supercurrents within the superconducting dots. These currents produce a complex magnetic field pattern, which is inscribed into the permalloy film above. The results are published in Advanced Science.
  • Nanotechnology for energy materials: Electrodes like leaf veins
    Science Highlight
    27.09.2016
    Nanotechnology for energy materials: Electrodes like leaf veins
    Nano-sized metallic wires are attracting increasing attention as conductive elements for manufacturing transparent electrodes, which are employed in solar cells and touch screen panels. In addition to high electric conductivity, excellent optical transmittance is one of the important parameters for an electrode in photovoltaic applications. An international team headed by HZB scientist Prof. Michael Giersig has recently demonstrated for these applications that networks of metallic mesh possessing fractal-like nano-features surpass other metallic networks in utility. These findings have now been published in the most recent edition of the renowned journal Nature Communications.
  • Advancing methodology at BESSY II: Automated evaluation speeds up the search for new active substance
    Science Highlight
    26.09.2016
    Advancing methodology at BESSY II: Automated evaluation speeds up the search for new active substance
    The macromolecular crystallography (MX) beamlines at the BESSY II X-ray source are specially designed to highly automated structural analyses of protein crystals. With up to now more than 2000 solved structures of protein molecules, these beamlines are by far the most productive ones in Germany and are in vigorous demand by groups from either an academic and industrial research area. Now teams from HZB and Philipps-Universität Marburg in Germany have automated the evaluation of data records as well. The newly developed expert system identifies small molecule fragments bound to proteins in the raw X-ray diffraction data. These fragments represent suitable starting points for the development of an active substance. Using a series of 364 samples, the collaborating partners demonstrated that the expert system works reliably and can speed up the search for a suitable active agents.
  • Manual of characterisation techniques for thin-film solar cells published with the involvement of HZB researchers
    Science Highlight
    15.09.2016
    Manual of characterisation techniques for thin-film solar cells published with the involvement of HZB researchers
    In August 2016, the second, enlarged edition of the reference book "Advanced Characterization Techniques for Thin-Film Solar Cells" appeared from renowned publisher WILEY-VCH. Co-editor is HZB researcher Dr. Daniel Abou-Ras. A total of eleven authors from HZB wrote chapters for this reference. It provides a comprehensive overview of many characterisation and modelling techniques that can be employed for solar cell materials and components.
  • Novel state of matter: Observation of a quantum spin liquid
    Science Highlight
    25.07.2016
    Novel state of matter: Observation of a quantum spin liquid
    A novel and rare state of matter known as a quantum spin liquid has been empirically demonstrated in a monocrystal of the compound calcium-chromium oxide by team at HZB. What is remarkable about this discovery is that according to conventional understanding, a quantum spin liquid should not be possible in this material. A theoretical explanation for these observations has now also been developed. This work deepens our knowledge of condensed matter and might also be important for future developments in quantum information. The results have just been published in Nature Physics.
  • New effect on laser induced switching for higher data densities
    Science Highlight
    22.06.2016
    New effect on laser induced switching for higher data densities
    An international collaboration has now demonstrated a completely new approach to increase data density in storage media. They used ultra-short laser pulses to trigger a phase transition in the ferromagnetic material BaFeO3 (BFO). Experiments at the Femtospex facility at BESSY II of Helmholtz-Zentrum Berlin showed that by inducing this phase transition, magnetic domains can be easily manipulated. These magnetic domains are otherwise very stable and therefore suited for long-time data storage. The results have been published in Phys. Rev. Letters now.
  • User Community Science: Soft decoupling of organic molecules on metal
    Science Highlight
    22.06.2016
    User Community Science: Soft decoupling of organic molecules on metal
    An international team has discovered an elegant way to decouple organic nanosheets grown on metal surfaces. After iodine intercalation, measurements at the synchrotron source BESSY II of Helmholtz-Zentrum Berlin (HZB) showed that a network of organic molecules behaved almost as it was free-standing. The strong influence of the metal on the network was reduced. This opens up new ways to transfer organic nanostructures from metal surfaces onto more suitable substrates for molecular electronics.  The results have been published in “Angewandte Chemie”.
  • Progress in the application of spin effects in graphene: from the metal to the semiconductor world
    Science Highlight
    16.06.2016
    Progress in the application of spin effects in graphene: from the metal to the semiconductor world
    Graphene on silicon carbide could be an interesting candidate for future spintronik components. Squeezing gold atoms between the semiconducting substrate and graphene does enhance spin-orbit interaction at hot spots and shows ways to controll the spins. First results at BESSY II are now published in Applied Physics Letters.
  • Spintronics: Resetting the future of Heat Assisted Magnetic Recording
    Science Highlight
    14.06.2016
    Spintronics: Resetting the future of Heat Assisted Magnetic Recording
    A HZB team has examined thin films of Dysprosium-Cobalt sputtered onto a nanostructured membrane at BESSY II. They showed that new patterns of magnetization could be written in a quick and easy manner after warming the sample to only 80 °Celsius, which is a much lower temperature as compared to conventional Heat Assisted Magnetic Recording systems. This paves the way to fast and energy efficient ultrahigh density data storage. The results are published now in the new journal Physical Review Applied.
  • User research at BESSY II: nanostructures in human teeth
    Science Highlight
    02.06.2016
    User research at BESSY II: nanostructures in human teeth

    Dentin is one of the most durable biological materials in the human body. Researchers from Charité–Universitätsmedizin Berlin were able to show that the reason for this can be traced to its nanostructures and specifically to the interactions between the organic and inorganic components. Measurements performed at BESSYII, the Helmholtz-Zentrum Berlin's synchrotron radiation source, showed that it is the mechanical coupling between the collagen protein fibers and mineral nanoparticles which renders dentin capable of withstanding extreme forces. Results from this research have been recently published in the journal Chemistry of Materials.
  • Ferrous chemistry in aqueous solution unravelled
    Science Highlight
    11.05.2016
    Ferrous chemistry in aqueous solution unravelled
    An HZB team has combined two different analytical methods at the BESSY II synchrotron source in order to extract more information about the chemistry of transition-metal compounds in solution. These kinds of compounds can act as catalysts to promote desirable reactions in energy materials, but their behaviour has not been completely understood thus far.  The team demonstrated how a detailed picture of the electronic states can be ascertained by systematically comparing all of the interactive electronic processes in a simple system of aqueous iron(II).  The results have now been published in Scientific Reports, the open access journal from Nature Group publishing.
  • Spintronics for future information technologies: spin currents in topological insulators controlled
    Science Highlight
    29.04.2016
    Spintronics for future information technologies: spin currents in topological insulators controlled
    An international team headed by HZB researcher Jaime Sánchez-Barriga has shown how spin-polarised currents can be initiated in a controlled manner within samples of topological insulator material. In addition, they were able to manipulate the orientation of the spins of these currents. They thereby demonstrated that this class of materials is suitable for data processing based on spin. The work has been published in the renowned periodical Physical Review B and was selected as “Editor’s Suggestion” article.
  • Thin-film solar cells: how defects appear and disappear in CIGSe-cells
    Science Highlight
    21.04.2016
    Thin-film solar cells: how defects appear and disappear in CIGSe-cells
    Concentration of copper plays a crucial role

    An international collaboration of German, Israeli, and British teams has investigated the deposition of thin chalcopyrite layers. They were able to observe specific defects as these formed during deposition and under what conditions they self-healed using the BESSY II X-ray source at the Helmholtz Zentrum Berlin. The results of their research provide clues to optimising fabrication processes and have now been published in Energy & Environmental Science.

  • Riddle of missing efficiency in zinc oxide-based dye-sensitised solar cells solved.
    Science Highlight
    13.04.2016
    Riddle of missing efficiency in zinc oxide-based dye-sensitised solar cells solved.
    To convert solar energy into electricity or solar fuels, you need specialised systems of materials such as those consisting of organic and inorganic thin films. Processes at the junction of these films play a decisive role in converting the solar energy. Now a team at HZB headed by Prof. Emad Aziz has used ultra-short laser pulses and observed for the first time directly how boundary states form between the organic dye molecules and a zinc-oxide semiconductor layer, temporarily trapping the charge carriers. This explains why zinc-oxide (ZnO) dye-sensitised solar cells have not yet met expectations. The results evolved from collaboration between Monash University (Australia) and Joint Lab partners Helmholtz Zentrum Berlin (HZB) and the Freie Universität Berlin (FU Berlin). They have now been published online by Nature in the open access magazine Scientific Reports.
  • Energy storage materials under pressure
    Science Highlight
    08.04.2016
    Energy storage materials under pressure
    Surprising discovery at BESSY II: the adsorption capacity of MOFs does not rise automatically with increasing pressure
  • Solar fuels:a refined protective layer for the “artificial leaf”
    Science Highlight
    21.03.2016
    Solar fuels:a refined protective layer for the “artificial leaf”
    A team at the HZB Institute for Solar Fuels has developed a process for providing sensitive semiconductors for solar water splitting (“artificial leaves”) with an organic, transparent protective layer. The extremely thin protective layer made of carbon chains is stable, conductive, and covered with catalysing nanoparticles of metal oxides. These accelerate the splitting of water when irradiated by light. The team was able to produce a hybrid silicon-based photoanode structure that evolves oxygen at current densities above 15 mA/cm2. The results have now been published in Advanced Energy Materials.

  • Measuring chemistry: local fingerprint of hydrogen bonding captured in experiments
    Science Highlight
    16.03.2016
    Measuring chemistry: local fingerprint of hydrogen bonding captured in experiments
    A team from Helmholtz-Zentrum Berlin has been able for the first time to measure how new bonds influence molecules: they have reconstructed the “energy landscape” of acetone molecules using measurement data from the Swiss Light Source (SLS) of the Paul Scherrer Institut, and thereby empirically established the formation of hydrogen bonds between acetone and chloroform molecules. The results have been published in Nature Scientific Reports and assist in understanding fundamental phenomena of chemistry.
  • Topological insulators: Magnetism is not causing loss of conductivity
    Science Highlight
    19.02.2016
    Topological insulators: Magnetism is not causing loss of conductivity
    If topological insulators are doped with impurities that possess magnetic properties, they lose their conductivity. Yet contrary to what has been assumed thus far, it is not the magnetism that leads to this. This has been shown by recent experiments with BESSY II at HZB. The results are now published in Nature Communications. Understanding these effects is crucial for applications of topological insulators in information technology.
  • Metal Oxide Sandwiches:  New option to manipulate  properties of interfaces
    Science Highlight
    04.02.2016
    Metal Oxide Sandwiches: New option to manipulate properties of interfaces
    A Franco-German cooperation has investigated a sandwich system of transition metal oxides at BESSY II. The scientists discovered a new option to control properties of the interface between the two layers, for instance the amount of charge transferred from one layer to the other or the emergence of ferromagnetism.  Their insights might help to create new properties at the interface, not present in the primary materials, maybe even novel forms of High Tc superconductivity.
  • An alternative to platinum: iron-nitrogen compounds as catalysts in graphene
    Science Highlight
    27.01.2016
    An alternative to platinum: iron-nitrogen compounds as catalysts in graphene
    Teams at HZB and TU Darmstadt have produced a cost-effective catalyst material for fuel cells using a new preparation process which they analysed in detail. It consists of iron-nitrogen complexes embedded in tiny islands of graphene only a few nanometres in diameter. It is only the FeN4 centres that provide the excellent catalytic efficiency – approaching that of platinum. The results are interesting for solar fuels research as well and have been published in the Journal of the American Chemical Society.
  • The solar technologies race: thin-film photovoltaics are catching up
    Science Highlight
    26.01.2016
    The solar technologies race: thin-film photovoltaics are catching up
    ZSW and HZB present current data – with new    opportunities for Europe’s solar industry
  • A Fast Way of Electron Orbit Simulation in Complex Magnetic Fields
    Science Highlight
    20.01.2016
    A Fast Way of Electron Orbit Simulation in Complex Magnetic Fields
    The design  of  advanced synchrotron radiation sources requires precise  algorithms  for the  simulation of electron trajectories in  complex magnetic fields. However, multi-parameter studies can  be very time consuming. Now, a team of the HZB has developed a new algorithm which significantly reduces the computation time.  This approach is now published in the renowned journal “Physical Review Special Topics Accelerator & Beams”.
  • Optimum band gap for hybrid silicon/perovskite tandem solar cell
    Science Highlight
    07.01.2016
    Optimum band gap for hybrid silicon/perovskite tandem solar cell
    Tandem solar cells based on silicon and perovskites have raised high hopes for future high efficiency solar modules.  A team led by perovskite solar cell pioneer Henry Snaith at the University of Oxford has now shown, with contributions by Bernd Rech and Lars Korte of the Helmholtz-Zentrum Berlin, that an ultimate efficiency of 30% should be attainable with such tandem cells. They discovered a structurally stable perovskite composition with its band gap tuned to an optimum value of 1.75 eV. The results have been published in "Science".
  • Alternative method for the representation of microstructures in polycrystalline materials
    Science Highlight
    18.12.2015
    Alternative method for the representation of microstructures in polycrystalline materials
    Also Raman microspectroscopy in an optical microscope provides the means to determine local crystal orientations of polycrystalline materials over large sample areas. This method can be used alternatively to electron backscatter diffraction in a scanning electron microscope. It was shown by a team from Helmholtz-Zentrum Berlin and the Federal Institute for Materials Research and Testing (BAM) that both characterization techniques result in similar orientation distribution maps on areas of several hundreds of square micrometers.
  • Doped organic semiconductors explored
    Science Highlight
    14.12.2015
    Doped organic semiconductors explored
    Organic semiconductor materials are already being employed today in solar cells and organic LEDs (OLEDs) amongst others. Until now, however, little was known about how the doping molecules are integrated into the chemical structure of organic semiconductors. The Molecular Systems Joint Research Team of the Helmholtz-Zentrum Berlin and Humboldt-Universität zu Berlin at BESSY II have now analysed this with surprising results. The molecules are not necessarily uniformly dispersed in the host lattice, as it is usual with inorganic semiconductors, but instead form what are known as co-crystallites. The doped organic semiconductor consists of a matrix of undoped crystallites in which such “mixed crystallites” are embedded. It is this very species that takes over the role as the actually doping molecule. The results were published in Nature Communications.
  • Whispering gallery modes in Silicon nanocones intensify luminescence
    Science Highlight
    26.11.2015
    Whispering gallery modes in Silicon nanocones intensify luminescence
    Silicon, a semiconducting material, reveals new talents when reduced to nanoscopic dimensions. A joint team at the HZB Institute of Nanoarchitectures for Energy Conversion and the Max Planck Institute for the Science of Light (MPL) has demonstrated this. Silicon nanocones generate 200 times as much infrared luminescence as comparably sized nanocolumns when excited by visible light. Modelling and experimental results show that due to their geometry, cones are able to sustain what is referred to as whispering gallery modes at infrared wavelengths which can intensify the silicon luminescence. New applications are conceivable, including silicon-based nanolasers.
  • Monolithic perovskite/silicon tandem solar cell achieves record efficiency
    Science Highlight
    28.10.2015
    Monolithic perovskite/silicon tandem solar cell achieves record efficiency
    Teams from the Helmholtz-Zentrum Berlin and École Polytechnique Fédérale de Lausanne, Switzerland, have been the first to successfully combine a silicon heterojunction solar cell with a perovskite solar cell monolithically into a tandem device. The hybrid tandem cell showed an efficiency of 18 per cent. That is the highest currently reported value for this type of device architecture. There are even prospects for the efficiency to reach as much as 30 per cent.
  • Scientists demonstrate how to improve ultrathin CIGSe solar cells by nanoparticles
    Science Highlight
    15.10.2015
    Scientists demonstrate how to improve ultrathin CIGSe solar cells by nanoparticles
    CIGSe solar cells  are made of a thin chalcopyrite layer consisting of Copper, Indium, Gallium and Selenium and can reach high efficiencies. Since Indium is becoming scarce and expensive, it is interesting to reduce the active CIGSe layer, which however decreases the efficiency quite strongly.  Now, scientists at Helmholtz-Zentrum Berlin have produced high quality ultrathin CIGSe layers and increased their efficiency by an array of tiny nanoparticles between the back contact and the active layer.
  • Graphene as a front contact for silicon-perovskite tandem solar cells
    Science Highlight
    02.10.2015
    Graphene as a front contact for silicon-perovskite tandem solar cells
    HZB team develops elegant process for coating fragile perovskite layers with graphene for the first time. Subsequent measurements show that the graphene layer is an ideal front contact in several respects.
  • Hydrogen from sunlight: new efficiency record for artificial photosynthesis
    Science Highlight
    15.09.2015
    Hydrogen from sunlight: new efficiency record for artificial photosynthesis
    An international team has now succeeded in considerably increasing the efficiency for direct solar water splitting. They are using a tandem solar cell whose surfaces have been selectively modified. The new record value is 14 % and thus considerably above the previous record of 12.4 % held by the National Renewable Energy Laboratory (NREL) in the USA, broken now for the first time in 17 years. Researchers from the Institute for Solar Fuels at the Helmholtz-Zentrum Berlin, TU Ilmenau, the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg and the California Institute of Technology (Caltech) participated in the collaboration. The results have been published in Nature Communications.
  • Charge transport in hybrid silicon solar cells
    Science Highlight
    17.08.2015
    Charge transport in hybrid silicon solar cells
    An HZB team headed by Prof. Silke Christiansen has made a surprising discovery about hybrid organic/inorganic solar cells. Contrary to expectations, a diode composed of the conductive organic PEDOT:PSS and an n-type silicon absorber material behaves more like a pn junction between two semiconductors than like a metal-semiconductor contact (Schottky diode). Their results have now been published in the Nature journal Scientific Reports and could point the way toward improvements in hybrid solar cells.
  • Transparent, electrically conductive network of encapsulated silver nanowires – a novel electrode for optoelectronics
    Science Highlight
    31.07.2015
    Transparent, electrically conductive network of encapsulated silver nanowires – a novel electrode for optoelectronics
    A team headed by Prof. Silke Christiansen has developed a transparent electrode with high electrical conductivity for solar cells and other optoelectronic components – that uses minimal amounts of material. It consists of a random network of silver nanowires that is coated with aluminium-doped zinc oxide. The novel electrode requires about 70 times less silver than conventional silver grid electrodes, but possesses comparable electrical conductivity.
  • Spins in Graphene with a Hedgehog Texture
    Science Highlight
    27.07.2015
    Spins in Graphene with a Hedgehog Texture
    HZB researchers demonstrate a fundamental property of the electron spin in graphene
  •  Depletion and enrichment of chlorine in perovskites observed
    Science Highlight
    10.07.2015
    Depletion and enrichment of chlorine in perovskites observed
    X-ray spectroscopy at BESSY II reveals inhomogenous distribution of chlorine in a special class of perovskite materials. The discovery could help to enhance efficiencies of perovskite thin film solar cells by controlled processing to optimize the chlorine distribution.
  • Emergence of a “devil’s staircase” in a spin-valve system
    Science Highlight
    01.07.2015
    Emergence of a “devil’s staircase” in a spin-valve system
    A Japanese-German team observes at BESSY II how spins form unusual magnetic structures in a complex cobalt oxide single crystal. Such a material offers new perspectives for spintronic applications.
  • Towards graphene biosensors
    Science Highlight
    24.06.2015
    Towards graphene biosensors
    For the first time, a team of scientists has succeeded in precisely measuring and controlling the thickness of an organic compound that has been bound to a graphene layer. This might enable graphene to be used as a sensitive detector for biological molecules in the future.
  •  Strong teeth: Nanostructures under stress make teeth crack resistant
    Science Highlight
    10.06.2015
    Strong teeth: Nanostructures under stress make teeth crack resistant
    Human teeth have to serve for a lifetime, despite being subjected to huge forces. But the high failure resistance of dentin in teeth is not fully understood. An interdisciplinary team led by scientists of Charité – Universitätsmedizin Berlin has now analyzed the complex structure of dentin. At the synchrotron sources BESSY II at HZB, Berlin, Germany, and the European Synchrotron Radiation Facility ESRF, Grenoble, France, they could reveal that the mineral particles are precompressed. The internal stress works against crack propagation and increases resistance of the biostructure.
  • Realistic computer model of battery electrodes
    Science Highlight
    02.06.2015
    Realistic computer model of battery electrodes
    A research team has developed a new approach for more realistic computer models of battery electrodes. They combined images from synchrotron tomography that capture three-dimensional structure at micron resolution with those from an electron microscope that can even resolve nanometre-scale features over a small section. They were able to transfer these nano-features to areas beyond the section using a mathematical model. Properties and processes within battery electrodes can now be simulated highly realistically using this method.
  • New options for spintronic devices: Switching between 1 and 0 with low voltage
    Science Highlight
    18.05.2015
    New options for spintronic devices: Switching between 1 and 0 with low voltage
    Scientists from Paris and Helmholtz-Zentrum Berlin have been able to switch ferromagnetic domains on and off with low voltage in a structure made of two different ferroic materials. The switching works slightly above room temperature. Their results, which are published online in  Scientific Reports, might inspire future applications in low-power spintronics, for instance for fast and efficient data storage.
  • Artificial photosynthesis: New, stable photocathode with great potential
    Science Highlight
    13.05.2015
    Artificial photosynthesis: New, stable photocathode with great potential
    A team at the HZB Institute for Solar Fuels has developed a new composite photocathode for generating hydrogen with high quantum efficiency using sunlight. This enables solar energy to be stored chemically.The photocathode consists of a thin film of chalcopyrite produced by HZB/PVcomB coated with a newly developed thin film of photoresistant titanium dioxide containing platinum nanoparticles. This layer does not only protect the chalcopyrite thin film from corrosion, it additionally acts as a catalyst to speed-up the formation of hydrogen as well as being a novel photodiode itself that even shows photoelectric current density and voltage comparable to those of a chalcopyrite-based thin film solar cell.
  • Inkjet printing process for Kesterite solar cells
    Science Highlight
    06.05.2015
    Inkjet printing process for Kesterite solar cells
    A research team at HZB has developed an inkjet printing technology to produce kesterite thin film absorbers (CZTSSe). Based on the inkjet-printed absorbers, solar cells with total area conversion efficiency of up to 6.4 % have been achieved. Although this is lower than the efficiency records for this material class, the inkjet printing minimizes waste and has huge advantages for industrial production.
  • Neutrons and X-rays show how to prepare durable tooth cement
    Science Highlight
    13.03.2015
    Neutrons and X-rays show how to prepare durable tooth cement
    There are many ways to mix cements for tooth fillings, but it can be difficult to tell which way works best. Now, a team of scientists from Copenhagen, Denmark, has come up with an answer: They used neutron imaging and x-ray-microtomography at HZB to analyze fillings with glass ionomere cements, prepared by different methods. Their results, now published in  Scientific Reports, demonstrate how much the order of mixing steps matters to obtain a nearly homogenous filling without large liquid-filled pores which reduce stability.
  • Learning by eye: silicon micro-funnels increase the efficiency of solar cells
    Science Highlight
    24.02.2015
    Learning by eye: silicon micro-funnels increase the efficiency of solar cells
    A biological structure in mammalian eyes has inspired a team headed by Silke Christiansen to design an inorganic counterpart for use in solar cells. With the help of conventional semiconductor processes, they etched micron-sized vertical funnels shoulder-to-shoulder in a silicon substrate. Using mathematical models and experiments, they tested how these kind of funnel arrays collect incident light and conduct it to the active layer of a silicon solar cell. Their result: this arrangement of funnels increases photo absorption by about 65% in a thin-film solar cell fitted with such an array and is reflected in considerably increased solar cell efficiency, among other improved parameters.
  • Stretch and relax! – Losing one electron switches magnetism on in dichromium
    Science Highlight
    23.02.2015
    Stretch and relax! – Losing one electron switches magnetism on in dichromium
    An international team of scientists from Berlin, Freiburg and Fukuoka has provided the first direct experimental insight into the secret quantum life of dichromium. Whereas in its normal state the 12 valence electrons form a strong multiple bond between the two chromium atoms, removing only one electron changes the situation dramatically: 10 electrons localize and align their spins, thus resulting in ferromagnetic behavior of the dichromium-kation. The bonding is done by one electron only, resulting in a much weaker bond. The scientists used the unique Nanocluster Trap experimental station at the BESSY II synchrotron radiation source at Helmholtz-Zentrum Berlin and published their results in the Journal Angewandte Chemie.
  • Insight into inner magnetic layers
    Science Highlight
    17.02.2015
    Insight into inner magnetic layers
    Measurements at BESSY II have shown how spin filters forming within magnetic sandwiches influence tunnel magnetoresistance – results that can help in designing spintronic components.
  • Details of a crucial reaction: Physicists uncover oxidation process of carbon monoxide on a ruthenium surface
    Science Highlight
    12.02.2015
    Details of a crucial reaction: Physicists uncover oxidation process of carbon monoxide on a ruthenium surface
    An international team has observed the elusive intermediates that form when carbon monoxide is oxidized on a hot ruthenium metal surface. They used ultrafast X-ray and optical laser pulses at the SLAC National Accelerator Laboratory, Menlo Park, California. The reaction between carbon monoxide and adsorbed oxygen atoms was initiated by heating the ruthenium surface with optical laser pulses. Directly afterwards, changes in the electronic structure of oxygen atoms were probed via X-ray absorption spectroscopy as they formed bonds with the carbon atoms.The observed transition states are consistent with density functional theory and quantum oscillator models.
  • Forschungsmagazin „Sichtbar“: Große Forschung, interessante Leute, neue Perspektiven
    Science Highlight
    12.02.2015
    Forschungsmagazin „Sichtbar“: Große Forschung, interessante Leute, neue Perspektiven
    Auf dem Titelbild prangt ein echter Star: Der neue Hochfeldmagnet, umgeben und beklettert von den Physikerinnen und Experten, die in den letzten sieben Jahren am Aufbau dieses weltweit einzigartigen Großgeräts mitgearbeitet haben. Auch im Heft finden Sie Bilder und Geschichten aus der HZB-Forschung, die wir manchmal auch aus einer anderen Perspektive erzählen als sonst.
  • Spintronics: Dance of the nanovortices
    Science Highlight
    02.02.2015
    Spintronics: Dance of the nanovortices
    The trajectories of small magnetic entities referred to as skyrmions have been captured and recorded with the help of X-ray holography. Researchers gained new insight from the analysis of this motion: these nanoscale vortices possess mass. The discovery is published in Nature Physics 2 February 2015.
  • Holes in valence bands of nanodiamonds discovered
    Science Highlight
    28.01.2015
    Holes in valence bands of nanodiamonds discovered
    Researchers hope that their properties might be altered to permit nanodiamonds to be used as catalysts for generating hydrogen from sunlight
  • Just published: New book on CZTS-based thin film solar cells published
    Science Highlight
    23.01.2015
    Just published: New book on CZTS-based thin film solar cells published
    In time at the start of the new year the book "Copper Zinc Tin Sulfide-based Thin Film Solar Cells" was published (Wiley, 2015, ed. by K. Ito), in which also scientists from the HZB are involved. Thomas Unold, Justus Just and Hans-Werner Schock provided the chapter "Coevaporation of CZTS Films and Solar Cells", Susan Schorr has contributed the chapter "Crystallographic Aspects of CZTS".
  • Messages From Space
    Science Highlight
    22.01.2015
    Messages From Space
    Geologists from the University of Cambridge uncover hidden magnetic messages from the early solar system in meteorites measured at BESSY II. The team of scientists led by Dr. Richard Harrison has captured information stored inside tiny magnetic regions in meteorite samples using the PEEM-Beamline at BESSY II.
  • The path to artificial photosynthesis
    Science Highlight
    21.01.2015
    The path to artificial photosynthesis
    HZB researchers describe efficient manganese catalyst capable of converting light to chemical energy
  • Batman lights the way to compact data storage
    Science Highlight
    12.01.2015
    Batman lights the way to compact data storage
    Researchers at the Paul Scherrer Institute (PSI) have succeeded in switching tiny, magnetic structures using laser light and tracking the change over time. In the process, a nanometre-sized area bizarrely reminiscent of the Batman logo appeared. The research results could render data storage on hard drives faster, more compact and more efficient.
  • Maximum efficiency, minimum materials and complexity
    Science Highlight
    12.01.2015
    Maximum efficiency, minimum materials and complexity
    Silicon-based thin-film solar cell with a supplementary organic layer can utilise infrared light as well
  • New light shed on electron spin flips
    Science Highlight
    06.01.2015
    New light shed on electron spin flips
    Researchers from Berlin Joint EPR Lab at Helmholtz-Zentrum Berlin (HZB) and University of Washington (UW) derived a new set of equations that allows for calculating electron paramagnetic resonance (EPR) transition probabilities with arbitrary alignment and polarization of the exciting electromagnetic radiation. The validity of the equations could be demonstrated with a newly designed THz-EPR experiment at HZB’s storage ring BESSY II. This progress is relevant for a broad community of EPR users and is published in Physical Review Letters on January 6. 2015 (DOI 10.1103/PhysRevLett.114.010801).
  • Universality of charge order in cuprate superconductors
    Science Highlight
    22.12.2014
    Universality of charge order in cuprate superconductors
    Charge order has been established in another class of cuprate superconductors, highlighting the importance of the phenomenon as a general property of these high-Tc materials.
  •  Organic layer adds light particles
    Science Highlight
    27.11.2014
    Organic layer adds light particles
    Solar cells can only use photons with energies above a specific threshold to generate electricity. A German-Australian research collaboration has now combined solar cells with an organic material which can “add up” low-energy photons to yield higher-energy light, which can then be harvested by the solar cell. In an invited review paper published in the prestigious journal Energy & Environmental Science the scientists give an overview on the fascinating phenomenon of photonic upconversion and report new results: The organic layers show less photo-degradation than suspected and may also be used for other optoelectronics applications.
  • Warping in topological insulators
    Science Highlight
    14.11.2014
    Warping in topological insulators
    Topological insulators are promising to develop into a material for lossless electricity and information transport. Now, Jaime Sánchez-Barriga and colleagues from HZB investigated for the first time whether the direction of motion of electrons in topological insulators affects their behavior. In their work they identified directions along which electrons are much more prone to scattering losses and cannot conduct as well. To explain their results, they included the spin of the electron and questioned an established theory. The results could push topological insulator research, especially when a future BESSY-VSR will be available to provide much shorter light pulses to study the dynamics of the electrons. Their investigation into the "warping" of topological insulators is published by Physical Review B and has been selected as "Editor's Suggestion". Only six percent of the articles  published there receive this sort of acclaim.
  • New light on the "Split Peak" in x-ray (RIXS) spectra of Alcohols
    Science Highlight
    14.10.2014
    New light on the "Split Peak" in x-ray (RIXS) spectra of Alcohols
    New study from Helmholtz-Zentrum Berlin in the journal "Structural Dynamics" makes sense of mysterious spectra, paving way for RIXS spectroscopy probe dynamic electronic structure of complex liquids and materials
  • Open Access: Webinar for Helmholtz Ph.D. students
    Science Highlight
    06.10.2014
    Open Access: Webinar for Helmholtz Ph.D. students
    As part of the international Open Access Week 2014, a series of events around the World will help canvass and inform about open access to knowledge.
  • Tage der Forschung in Adlershof
    Science Highlight
    29.09.2014
    Tage der Forschung in Adlershof
    Am 25. und 26. September fanden in Adlershof die jährlichen Tage der Forschung statt. Das HZB bot rund 90 Schülerinnen und Schülern in drei unterschiedlichen Programmpunkten einen Einblick in die Welt der Forschung.
  • “Multi-spectra glasses” for scanning electron microscopy
    Science Highlight
    26.09.2014
    “Multi-spectra glasses” for scanning electron microscopy
    Reflection zone plates produced by HZB enable lighter elements in material samples to be precisely detected using scanning electron microscopy (SEM) by providing high resolution in the range of 50-1120 eV.
  • Science Highlight
    26.09.2014
    German Society for Materials Science awards publication with HZB scientist as co-author

    At its annual conference on September 22, 2014, the German Society for Materials Science (DGM), presented the Werner Köster Award for best publication. The work, whose authors include HZB scientist Dr. Michael Tovar and which has been published in the International Journal of Materials Research, examines the catalytic effect of vanadium pentoxide in propene synthesis from propane using spectroscopic, microscopic, and radiographic methods.

  • Sichtbar: Das Forschungsmagazin aus dem HZB
    Science Highlight
    10.09.2014
    Sichtbar: Das Forschungsmagazin aus dem HZB
    Die neue Sichtbar ist erschienen. Mit Interviews, Hintergrundberichten und Meldungen zeigt das Magazin, an welchen Fragen HZB-Forscherinnen und -Forscher arbeiten: Von neuen Solarzellen bis hin zu Mikrogelen, aus denen sich komplexe funktionale Materialien für medizinische Anwendungen komponieren lassen, zum Beispiel für eine effizientere Dialyse.
  • Proteins: New class of materials discovered
    Science Highlight
    22.08.2014
    Proteins: New class of materials discovered
    German-Chinese research team gleans seminal insights into protein crystalline frameworks at HZB's BESSY II
  • Neuer „lichtblick“ online
    Science Highlight
    11.08.2014
    Neuer „lichtblick“ online
    Ein Denkmal im Ehrenhof der Humboldt-Universität erinnert seit kurzem an Lise Meitner – das erste Denkmal für eine Wissenschaftlerin in Deutschland überhaupt. Über die außergewöhnliche Wissenschaftlerin und die Entstehung der Bronze berichten wir in der aktuellen Ausgabe der HZB-Mitarbeiterzeitung „lichtblick“, die jetzt auch online ist.
  • Self-assembly of gold nanoparticles into small clusters
    Science Highlight
    04.08.2014
    Self-assembly of gold nanoparticles into small clusters
    Researchers at HZB in co-operation with Humboldt-Universität zu Berlin (HU, Berlin) have made an astonishing observation: they were investigating the formation of gold nanoparticles in a solvent and observed that the nanoparticles had not distributed themselves uniformly, but instead were self-assembled into small clusters.
  • Neutron Tomography technique reveals phase fractions of crystalline materials in 3-Dimensions
    Science Highlight
    31.07.2014
    Neutron Tomography technique reveals phase fractions of crystalline materials in 3-Dimensions
    Researchers at Helmholtz-Zentrum Berlin (HZB) and The University of Tennessee Knoxville (UTK) developed a novel method, based on energy-selective neutron imaging for visualization of crystalline phase distributions within the bulk of metallic samples.
  • Collecting light with artificial moth eyes
    Science Highlight
    01.07.2014
    Collecting light with artificial moth eyes
    Scientists at EMPA in Zürich and University of Basel have developed a photoelectrochemical cell, recreating a moth’s eye to drastically increase its light collecting efficiency. The cell is made of cheap raw materials – iron and tungsten oxide. Analyses at BESSY II have revealed which chemical processes are useful to facilitate the absorption of light.
  • “Muscled skin”: Simple formulas describe complex behaviors
    Science Highlight
    01.07.2014
    “Muscled skin”: Simple formulas describe complex behaviors
    HZB researchers help chemists understand polymeric "biomimetic" materials' mechanical properties
  • Electrostatics do the trick
    Science Highlight
    18.06.2014
    Electrostatics do the trick
    A simple model describes what happens between organic semiconductors and metals
  • Sharper imaging using X-rays
    Science Highlight
    18.06.2014
    Sharper imaging using X-rays
    HZB team develops three-dimensional volume diffraction optics for X-rays
  • #HZBzlog gewinnt Deutschen Preis für Onlinekommunikation als beste Microsite
    Science Highlight
    22.05.2014
    #HZBzlog gewinnt Deutschen Preis für Onlinekommunikation als beste Microsite
    Seit etwa vier Monaten ist das HZB-Zukunftslogbuch #HZBzlog mit seiner ungewöhnlichen Episodenstruktur online, und es findet immer mehr Fans. Die als Langzeitdokumentation angelegte Seite öffnet ein Fenster in die Forschung und gibt den Blick frei auf die Geschichten hinter den Kulissen. Täglich surfen zwischen 500 und 1.000 Menschen auf der Seite und warten gespannt auf neue lebendige Einträge rund um die großen Zukunftsprojekte am HZB. Vier Monate nach dem Start gewinnt das neue HZB-Portal nun den von der Deutschen Presseakademie herausgegebenen "Deutschen Preis für Onlinekommunikation" und ist auf dem besten Weg, ein Erfolg zu werden.
  • Neuer Lichtblick erschienen
    Science Highlight
    20.05.2014
    Neuer Lichtblick erschienen
    Am Campus Wannsee entstehen neue Labore für die Materialsynthese: In unserer Mitarbeiterzeitung "lichtblick" berichten wir erstmals über das neue Bauvorhaben, das Materialforscherinnen und -forscher anlocken soll. Die Labore werden benötigt, um erfolgreich neuartige Materialkonzepte für die Energieumwandlung und -speicherung zu charakterisieren.
  • A new concept for the treatment of cancer
    Science Highlight
    08.04.2014
    A new concept for the treatment of cancer
    A team of researchers from five Swedish universities has identified a new way to treat cancer. They present their concept in the journal „Nature“. It is based on inhibiting a specific enzyme called MTH1. Cancer cells, unlike normal cells, need MTH1 to survive. Without this enzyme, oxidized nucleotides are incorporated into DNA, resulting in lethal DNA double-strand breaks in the cancer cells. The research group at Stockholm University has determined the structure of MTH1 based on diffraction measurements at HZB´s MX-beamline at BESSY II. These detailed structural studies are important for the development of efficient inhibitors targeting MTH1.
  • Controlling electron spins by light
    Science Highlight
    27.03.2014
    Controlling electron spins by light
    Researchers of HZB manipulate the electron spin at the surface of topological insulators systematically by light
  • HZB-Zeitung "Lichtblick" erschienen
    Science Highlight
    20.02.2014
    HZB-Zeitung "Lichtblick" erschienen
    Viele Menschen, die in einem Forschungszentrum arbeiten, bleiben unsichtbar. Sie sind Dienstleister für die Wissenschaftlerinnen und Wissenschaftler – oder machen, wie der Strahlenschutzexperte, Dr. Guido Buchert, das Forschen an den Großgeräten erst möglich. In dieser Ausgabe stellen wir seinen Berufsweg und sein höchst verantwortungsvolles Aufgabengebiet vor.
  • What makes superalloys super - hierarchical microstructure of a superalloy
    Science Highlight
    14.01.2014
    What makes superalloys super - hierarchical microstructure of a superalloy
    Researchers have observed for the first time in detail how a hierarchical microstructure develops during heat treatment of a superalloy
  • New holographic process uses image-stabilised X-ray camera
    Science Highlight
    07.01.2014
    New holographic process uses image-stabilised X-ray camera
    A team headed by Stefan Eisebitt has developed a new X-ray holography method that will enable snap-shots of dynamic processes at highest spatial resolution. The efficiency of the new method is based on a X-ray focussing optics being firmly fixed to the object to be imaged. While this approach initially provides a blurry image, this can be focussed in the computer based on the hologram information. At the same time, the rigid connection between the object and the focussing optics elegantly solves the problem of vibration induced jitter that plays an enormous role at the nanometre scale.
  • Charge Order competes with superconductivity
    Science Highlight
    19.12.2013
    Charge Order competes with superconductivity
    Today in Science Express: Charge carriers in cuprate high-Tc superconductors form nanostripes that suppress superconductivity, as shown by guest researchers from Princeton and Vancouver using synchrotron radiation at BESSY II
  • HZB-Zeitung "lichtblick" erschienen
    Science Highlight
    13.11.2013
    HZB-Zeitung "lichtblick" erschienen
    In der aktuellen Ausgabe der Lichtblick stellen wir Ihnen Mitarbeiterinnen und Mitarbeiter aus dem HZB vor. Jessica Neumann leitet das Rechnungs- und Finanzwesen und stellt sicher, dass das HZB immer genug Geld auf dem Konto hat - eine herausfordernde Aufgabe, die Fingerspitzengefühl und Kommunikationsstärke erfordert.
  • Now available: Highlights 2012 - the annual report with reseach highlights at HZB
    Science Highlight
    06.09.2013
    Now available: Highlights 2012 - the annual report with reseach highlights at HZB
    The Annual Report with research highlights is now available und could be downloaded.
  • Neue "lichtblick" erschienen
    Science Highlight
    23.08.2013
    Neue "lichtblick" erschienen
    Großes Interview mit der Geschäftsführung zur Zukunft des HZB
  • Researchers from HZB open a door for solid state physics
    Science Highlight
    21.08.2013
    Researchers from HZB open a door for solid state physics
    Laser processes observed with X-rays on a solid
  • Better insight into molecular interactions
    Science Highlight
    21.08.2013
    Better insight into molecular interactions
    How exactly atoms and molecules in biochemical solutions or at solid-liquid interfaces do interact, is a question of great importance. Answers will provide insights at processes in catalysts, smart functional materials and even physiological processes in the body, which are essential for health. Until now, scientists could have a look at these interactions by methods of spectroscopy, but it was hard to distinguish the many different interactions, which take place simultaneously.
  • Ideal nanocrystal produced from bulk plastics
    Science Highlight
    14.08.2013
    Ideal nanocrystal produced from bulk plastics
    Polyethylene is an inexpensive commodity plastic found in many household objects. Now, a consortium of researchers from Constance, Bayreuth, and Berlin has successfully used this plastic to synthesize the ideal polymer nanocrystal. The prerequisite was a new type of catalyst produced by Constance University researchers as well as a combination of unique analytic tools like those found at the Helmholtz Zentrum Berlin (HZB). The crystalline nanostructure, which gives the polymer its new properties, could prove of interest to production of new kinds of coatings. The scientists’ findings are being published in the Journal of the American Chemical Society’s current issue (DOI: 10.1021/ja4052334).
  • Melanie Timpel receives Acta Student Award
    Science Highlight
    08.08.2013
    Melanie Timpel receives Acta Student Award
    Dr. Melanie Timpel's submission to the journal Acta Materialia made her one of this year's recipients of the 2,000 dollar 2012 Acta Materialia Student Award. The award is considered a high distinction conferred upon up-and-coming scientists. The award ceremony is scheduled for October 28, 2013, as part of the Materials Science & Technology Conference (MS&T) in Montreal, Canada.
  • Picosecond accurate slow-motion confirms oxide materials exhibit considerably faster switching properties than do semi-conductors
    Science Highlight
    29.07.2013
    Picosecond accurate slow-motion confirms oxide materials exhibit considerably faster switching properties than do semi-conductors
    As part of an international team of researchers, scientists at the Helmholtz Center Berlin (HZB) have observed the switching mechanism from a non-conducting to a conducting state in iron oxide (specifically, magnetite) with previously unrealized precision. This switching mechanism - which, in oxides, proceeds in two consecutive steps and which is thousands of times faster than it is in current transistors - is described in the current epub-ahead-of-print issue of the scientific journal Nature Materials (DOI: 10.1038/NMAT3718).  
  • Watching catalysts at work – at the atomic scale
    Science Highlight
    25.07.2013
    Watching catalysts at work – at the atomic scale
    Innovative combination of methods at HZB leads to fundamental insights in catalyst research
  • Watching solar cells grow
    Science Highlight
    27.06.2013
    Watching solar cells grow
    For the first time, a team of researchers at the HZB led by Dr. Roland Mainz and Dr. Christian Kaufmann has managed to observe growth of high-efficiency chalcopyrite thin film solar cells in real time and to study the formation and degradation of defects that compromise efficiency. To this end, the scientists set up a novel measuring chamber at the Berlin electron storage ring BESSY II, which allows them to combine several different kinds of measuring techniques. Their results show during which process stages the growth can be accelerated and when additional time is required to reduce defects. Their work has now been published online in Advanced Energy Materials.
  • Crystal-clear method for distinguishing between glass and fluids
    Science Highlight
    28.05.2013
    Crystal-clear method for distinguishing between glass and fluids
    Many solids are produced from melting. Depending on how quickly they cool off, invariably, internal tensile stresses begin to build up. One example are Prince Rupert's Drops, or Dutch tears: you can hit their thick end with a hammer without breaking them while a slight pressure applied to their thin end is enough to shatter the entire tear. The properties of safety or even gorilla glass are determined to a large extent by their internal tensile stresses. However, until now, our understanding of the unique characteristics exhibited by the condition of the glass as compared with a tough molten mass was spotty at best. Now, a collaboration of several German and Cretian research teams has offered a surprisingly simple model to explain the difference between glass and molten materials.
  • Zwei Humboldt-Stipendiaten forschen am HZB: In der neuen Lichtblick stellen wir Jan Heyda und Stefano Angioletti-Uberti vor
    Science Highlight
    15.05.2013
    Zwei Humboldt-Stipendiaten forschen am HZB: In der neuen Lichtblick stellen wir Jan Heyda und Stefano Angioletti-Uberti vor
    Die Qualität des Alexander-von-Humboldt-Stipendiums ist weltweit anerkannt. Die Nachwuchswissenschaftler Stefano Angioletti-Uberti und Jan Heyda haben sich für dieses Stipendium entschieden, obwohl sie gleich mehrere Angebote für einen Forschungsaufenthalt im Ausland bekommen hatten. Beide forschen am HZB-Institut für Weiche und Funktionale Materialien bei Joachim Dzubiella. Sie interessieren sich für stimuli-responsive Polymaterialien. Wir stellen sie in der neuen Ausgabe der Lichtblick vor.
  • Magnetic fingerprints of interface defects in silicon solar cells detected
    Science Highlight
    27.03.2013
    Magnetic fingerprints of interface defects in silicon solar cells detected
    Using a highly sensitive method of measurement, HZB physicists have managed to localize defects in amorphous/crystalline silicon heterojunction solar cells. Now, for the first time ever, using computer simulations at Paderborn University, the scientists were able to determine the defects' exact locations and assign them to certain structures within the interface between the amorphous and crystalline phases.
  • Schwache Dotierung verbessert  polymerbasierte Feldeffekttransistoren
    Science Highlight
    13.03.2013
    Schwache Dotierung verbessert polymerbasierte Feldeffekttransistoren
    In der organischen Elektronik haben sich Mischsysteme, in denen halbleitende Makromoleküle in einer isolierenden Polymermatrix eingebettet sind, als besonders geeignet für die Herstellung von  Transistoren erwiesen. Bislang waren die Gründe dafür nicht genau bekannt. Nun konnten Wissenschaftler aus mehreren Forschungseinrichtungen die komplexe Morphologie dieser Mischsysteme aufklären und damit die elektronischen Eigenschaften erklären.
  • Water fluctuations mediate lock-and-key fit
    Science Highlight
    16.01.2013
    Water fluctuations mediate lock-and-key fit
    Without water, life as we know, it would not exist. Nearly every biological binding process that takes place within a cell requires the presence of an aqueous environment. Here, tiny molecules called ligands fit like "keys" into their matching "locks" - docking sites on larger protein molecules. This in turn activates signals or leads to the production of some other substance by the cell. But what was previously unclear, was the part water plays in all this. Is water merely a passive transport medium or does it perform other, more active jobs as well? Now, HZB's own Prof. Dr. Joachim Dzubiella and a team of physicists have looked for answers to this question using a computer simulated model system. In the process, they discovered that water is capable of actively influencing the docking speed of the ligand through subtle interactions with other molecules' unique geometry and surface topography. Their findings could become important in drug delivery.
  • Science Highlight
    21.05.2008
    Towards imaging ultrafast evolution in a single shot

    Research carried out by BESSY scientists in collaboration with colleagues from SLAC and SOLEIL has been featured as Editors’ Choice in the Nov. 23 issue of the Science Magazine. In the Optics Letters article by W. F. Schlotter et al., multiplexed x-ray holograms generated simultaneously from many objects are presented. The feasibility of this approach implies that ultrafast pump-probe time sequences can be recorded with free electron x-ray lasers in this way.