On the way to mass production: perovskite silicon tandem cells
The cluster facility operated at HZB allows to produce large-area perovskite/silicon tandem solar cells. This facility, the only one of its kind in the world, helps to develop new industry-related processes, materials and solar cells. © B. Stannowski / HZB
In order to transfer tandem solar cells from laboratory scale to production, HZB is cooperating with the solar module manufacturer Meyer Burger, which has great expertise in heterojunction technology (HJT) for silicon modules. Within the framework of this cooperation, mass production-ready silicon bottom cells based on heterojunction technology are to be combined with a top cell based on perovskite technology.
Meyer Burger is a manufacturer of high-quality solar modules based on silicon heterojunction technology (HJT). Meyer Burger's research and development team has already developed HJT cells in recent years together with Bernd Stannowski's team at the Helmholtz-Zentrum Berlin.
The HZB has great expertise in the field of perovskite solar cells. Recently, laboratory tandem solar cells combining heterojunction and perovskite have achieved record efficiencies of over 31 percent, largely due to the work of Steve Albrecht's group. However, such record-breaking tandem cells have only the laboratory-standard areas of 1 cm² and are partly produced with processes that are not scalable.
"We are therefore delighted to be cooperating with Meyer Burger to transfer this fantastic technology into application," says Bernd Stannowski, who heads the cooperation at HZB. A new cluster facility (KOALA) will also be used. This globally unique facility, funded by the German Federal Ministry of Economics and Climate Protection (BMWK) and the Federal Ministry of Education and Research (BMBF), makes it possible to produce perovskite/silicon tandem solar cells in a vacuum on industry-standard large wafers.
"Meyer Burger manufactures in Europe and thus creates high-quality jobs. In doing so, the company is exploiting technologies that were developed in Europe," says Rutger Schlatmann, director of the Photovoltaics Competence Centre Berlin (PVcomB) at HZB. The new cooperation agreement is set to run for three years.
- Battery research with the HZB X-ray microscopeNew cathode materials are being developed to further increase the capacity of lithium batteries. Multilayer lithium-rich transition metal oxides (LRTMOs) offer particularly high energy density. However, their capacity decreases with each charging cycle due to structural and chemical changes. Using X-ray methods at BESSY II, teams from several Chinese research institutions have now investigated these changes for the first time with highest precision: at the unique X-ray microscope, they were able to observe morphological and structural developments on the nanometre scale and also clarify chemical changes.
- BESSY II: New procedure for better thermoplasticsBio-based thermoplastics are produced from renewable organic materials and can be recycled after use. Their resilience can be improved by blending bio-based thermoplastics with other thermoplastics. However, the interface between the materials in these blends sometimes requires enhancement to achieve optimal properties. A team from the Eindhoven University of Technology in the Netherlands has now investigated at BESSY II how a new process enables thermoplastic blends with a high interfacial strength to be made from two base materials: Images taken at the new nano station of the IRIS beamline showed that nanocrystalline layers form during the process, which increase material performance.
- Hydrogen: Breakthrough in alkaline membrane electrolysersA team from the Technical University of Berlin, HZB, IMTEK (University of Freiburg) and Siemens Energy has developed a highly efficient alkaline membrane electrolyser that approaches the performance of established PEM electrolysers. What makes this achievement remarkable is the use of inexpensive nickel compounds for the anode catalyst, replacing costly and rare iridium. At BESSY II, the team was able to elucidate the catalytic processes in detail using operando measurements, and a theory team (USA, Singapore) provided a consistent molecular description. In Freiburg, prototype cells were built using a new coating process and tested in operation. The results have been published in the prestigious journal Nature Catalysis.