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.
Halide perovskites have huge potential for solar cells and other optoelectronic applications. Solar cells based on metal-organic perovskites achieve efficiencies of more than 25 percent, they can be produced cheaply and with minimal energy consumption, but still require improvements in terms of stability and reliability. In recent years, research on this class of materials has boomed, producing a flood of results that is almost impossible to keep track of by traditional means. Under the keyword "perovskite solar", more than 19,000 publications had already been entered in the Web of Science (spring 2021).
FAIR data
Now 95 experts from more than 30 international research institutions have designed a database to systematically record findings on perovskite semiconductors. The data are prepared according to the FAIR principles, i.e. they are findable, accessible, interoperable and reusable. By reading the existing literature, the experts have collected more than 42,000 individual data sets, in which the data can be filtered and displayed according to various criteria such as material compositions or component type. Researchers from several teams at HZB were involved in this Herculean task.
New insights by AI
"Data has always been the basis of empirical science, but when data is collected in sufficiently large quantities and in a coherent way, it can be searched with modern algorithms and artificial intelligence and can provide completely new insights," says Jesper Jacobsson, coordinator of this project.
Interactive tools, easy uploads
The database provides analysis tools and graphical data visualizations that enable easy and interactive exploration, and also offers the option to easily upload new data from new peer-reviewed publications. "It's a wiki for perovskite solar cell research," says Eva Unger, counting on the participation of the research community: "In the future, this type of research data platform will offer us the opportunity to make our research data public according to FAIR principles in addition to established publication formats."
Not only science, but also industry will benefit: The database provides an overview of the current state of knowledge, while also uncovering gaps in knowledge from which new productive research questions can arise.
- A new way to control the magnetic properties of rare earth elementsThe special properties of rare earth magnetic materials are due to the electrons in the 4f shell. Until now, the magnetic properties of 4f electrons were considered almost impossible to control. Now, a team from HZB, Freie Universität Berlin and other institutions has shown for the first time that laser pulses can influence 4f electrons- and thus change their magnetic properties. The discovery, which was made through experiments at EuXFEL and FLASH, opens up a new way to data storage with rare earth elements.
- BESSY II shows how solid-state batteries degradeSolid-state batteries have several advantages: they can store more energy and are safer than batteries with liquid electrolytes. However, they do not last as long and their capacity decreases with each charge cycle. But it doesn't have to stay that way: Researchers are already on the trail of the causes. In the journal ACS Energy Letters, a team from HZB and Justus-Liebig-Universität, Giessen, presents a new method for precisely monitoring electrochemical reactions during the operation of a solid-state battery using photoelectron spectroscopy at BESSY II. The results help to improve battery materials and design.
- From waste to value: The right electrolytes can enhance glycerol oxidationWhen biomass is converted into biodiesel, huge amounts of glycerol are produced as a by-product. So far, however, this by-product has been little utilised, even though it could be processed into more valuable chemicals through oxidation in photoelectrochemical reactors. The reason for this: low efficiency and selectivity. A team led by Dr Marco Favaro from the Institute for Solar Fuels at HZB has now investigated the influence of electrolytes on the efficiency of the glycerol oxidation reaction. The results can help to develop more efficient and environmentally friendly production processes.