Since the early days of photovoltaics in the 1950s, crystalline silicon solar cells have been the workhorse of this strongly growing industry. Since then great progress has been achieved in decreasing production costs from hundreds of US dollars per Wp down to values below $0.50/Wp. Also the technology itself has been strongly improved, as reflected by increasing cell efficiencies in research and production.
The notorious 20% hurdle, exceeded only by a small number of companies a few years ago, is now cleared by more and more companies mainly using a cell architecture with partial rear contact as PERC. A new generation of silicon solar cells utilizing passivating contacts such as a-Si/c-Si heterojunction or tunnel contacts is just around the corner. The record efficiency of silicon solar cells has reached 26.7%, getting closer to the theoretical limit of 29.4%.
In the future silicon-based tandem cells might enable the continuation of the success story of crystalline silicon photovoltaics even beyond this limit of pure silicon solar cells. In the last years, exciting results have been achieved with silicon-based tandem cells using perovskites or III-V materials as top cell.
Stefan Glunz was born in Dortmund, Germany in 1966. He received his diploma in physics in 1992 and his PhD in 1995 from University Freiburg.
After his PhD he started working as a scientist in the research group for high-efficiency silicon solar cells at the Fraunhofer Institute for Solar Energy Systems (ISE), Freiburg. Currently he heads the division "Photovoltaics - Research" at Fraunhofer ISE. His division at Fraunhofer ISE consists of 180 members including 25 PhD students and is focused on high-efficiency silicon solar cells, characterization and emerging photovoltaics. He has extensive experience in managing of both industry and public financed projects including several large European projects.
His research interests include the design, fabrication, and analysis of high-efficiency silicon solar cells. His work include the detailed characterization of the Si-SiO2 interface and other dielectric passivation layers as Al2O3, the analysis of the metastable defect in Czochralski silicon and of fundamental semiconductor parameters as Auger recombination in silicon, and the development of new technologies for the cost-efficient fabrication of high-efficiency silicon solar cells as laser-fired contacts and passivated contacts (TOPCon). His group at Fraunhofer ISE has set several international records including the highest efficiency for multicrystalline silicon solar cells (22.3%). Beyond pure silicon photovoltaics he is especially interested in silicon-based tandem cells. Recently a team of silicon and III-V specialists in his division at Fraunhofer ISE have managed to achieve an efficiency of 33.3% for a monolithical III-V/silicon tandem cell.
Since 2015 Stefan Glunz is full professor at the Albert Ludwig University of Freiburg, Germany. He is one of the founding professors of the new Institute for Sustainable Systems Engineering (INATECH) at the Technical Faculty. The research of INATECH is dedicated to Energy Systems, Sustainable Materials and Resilience. A new master programme was started in 2015 focussing on these topics in which he is responsible for courses as “Solar Energy” and “Photovoltaic Laboratory”. His research at the university focusses on emerging PV technologies as perovskite solar cells and tandem cells.
Prof. Glunz is the author/coauthor of more than 100 journal and 250 conference papers and founding editor of the IEEE Journal of Photovoltaics. In 2008 he received the Eni Award for the promotion of science and technology in the field of renewable energies. In 2014 he received the European Becquerel Prize for outstanding merits in photovoltaics. He is a scientific committee member for several conferences and workshops in the field of photovoltaics and has initiated an international conference on crystalline silicon photovoltaics (SiliconPV).