Approved! The EU INFINITE-CELL project
A large EU-sponsored research project on tandem solar cells in which HZB is participating begins in November 2017. The goal is to combine thin-film semiconductors made of silicon and kesterites into especially cost-effective tandem cells having efficiencies of over 20 per cent. Several large research institutions from Europe, Morocco, the Republic of South Africa, and Belarus will be working on the project, as well as two partners from industry.
“We not only have detailed experience with kesterite thin films, but also a wide spectrum of analytical methods at our disposal to characterise absorber materials very thoroughly”, explains Prof. Susan Schorr. The FUNDACIO INSTITUT DE RECERCA DE L’ENERGIA DE CATALUNYA (IREC), Spain – a long-term collaborating partner of the HZB, is coordinating the entire project. The project begins with a kick-off workshop in Brussels in November 2017.
Ambitious Goals
Goals of the project are quite concrete: the kesterite solar cells should reach an efficiency level of more than 14 per cent (currently they are just below 12%), while thin-film silicon cells made from recycled material should reach an efficiency level of over 16 per cent. Reaching more than 20 % is feasible because silicon uses a different energy region of light to generate electricity than kesterite does. When you combine both materials into one tandem solar cell, where you stack them upon one another or even grow one on the other, it enables a considerably larger proportion of solar energy to be converted into electrical energy. These kinds of especially efficient and also cost-effective solar modules might be employed in cladding, and on roof surfaces – for both buildings and vehicles – to generate power locally.
Why Kesterites?
“Kesterites are a very interesting class of materials”, emphasises Schorr. For even though other absorber materials like copper-indium-gallium-sulphides (CIGS) or metal-organic perovskite semiconductors are able to attain considerably higher efficiency levels today, kesterites trump them with two big advantages: kesterites consist of very abundant elements, and they are non-toxic.
Exchange between partner institutions
The project INFINITECELL, which is a Research and Innovation Staff Exchange (RISE) type funding, has a duration of four years. It is part of the Marie Skłodowska-Curie Actions Programme funded by the EU within Horizon 2020. This enables scientists over the coming years to travel to partner institutions in order to exchange experience, skills, and insights. The joint research is set out in a detailed Secondment Plan.
- Key technology for a future without fossil fuelsIn June and July 2025, catalyst researcher Nico Fischer spent some time at HZB. It was his sabbatical, he was relieved of his duties as Director of the Catalysis Institute in Cape Town for several months and was able to focus on research only. His institute is collaborating with HZB on two projects that aim to develop environmentally friendly alternatives using innovative catalyst technologies. The questions were asked by Antonia Rötger, HZB.
- 5000th patient treated with protons for eye tumoursFor more than 20 years, Charité – Universitätsmedizin Berlin and the Helmholtz-Zentrum Berlin (HZB) have been jointly offering proton radiation therapy for eye tumours. The HZB operates a proton accelerator in Berlin-Wannsee for this purpose, while Charité provides medical care for the patients. The 5000th patient was treated at the beginning of August.
- Iridium-free catalysts for acid water electrolysis investigatedHydrogen will play an important role, both as a fuel and as a raw material for industry. However, in order to produce relevant quantities of hydrogen, water electrolysis must become feasible on a multi-gigawatt scale. One bottleneck is the catalysts required, with iridium in particular being an extremely rare element. An international collaboration has therefore investigated iridium-free catalysts for acidic water electrolysis based on the element cobalt. Through investigations with various methods, among them experiments at the LiXEdrom at the BESSY II X-ray source in Berlin, they were able to elucidate processes that take place during water electrolysis in a cobalt-iron-lead oxide material as the anode. The study is published in Nature Energy.