Perovskite-Silicon Solar Cell Research Collaboration Hits 25.2% Efficiency

June 19, 2018 by Paul Shepard

Oxford PV™ announced that a 1 cm2 perovskite-silicon two-terminal tandem solar cell, engineered collaboratively with Helmholtz-Zentrum Berlin (HZB) and the Photovoltaics and Optoelectronics Device Group at the University of Oxford, led by Professor Snaith, had achieved 25.2% efficiency. The efficiency was certified by the Fraunhofer Institute for Solar Energy Systems ISE and was presented at the WCPEC conference this week.

"Perovskite-based tandem solar cells can use light particularly efficiently and therefore offer the opportunity to achieve even higher efficiencies. That is why we have significantly expanded our expertise with the new Helmholtz innovation laboratory HySPRINT," says Prof. Dr. Rutger Schlatmann, Director of the Competence Center Thin Film and Nanotechnology for Photovoltaics Berlin (PVcomB) at HZB.

"In our cooperation with Oxford PV, we aim to further optimize perovskite silicon tandem cells, demonstrate their scalability and facilitate their integration into large-area solar modules. For this new result we have optimized our high-efficiency silicon heterojunction bottom cell and developed an optical adaptation to the top cell using a very specific SiOx intermediate layer,” Prof. Schatmann added.

Dr Chris Case, Chief Technology Officer at Oxford PV commented, “The unique, optically enhanced architecture developed as part of this collaboration, minimises losses, and has helped us achieve this record setting efficiency.”

“With our combined progress in efficiency, stability and reliability, our perovskite-silicon tandem solar cell technology is now reaching its commercial potential. As with any new technology, the biggest challenge is transferring the technology from the lab and scaling up to high volume manufacturing.

“The company has already made great progress in this respect and our industrial pilot line is producing commercial sized 156 mm x 156 mm perovskite-silicon tandem solar cells for validation by our development partner – a major manufacturer of silicon solar cells and modules,” observed Dr. Case.

Oxford PV 156 mm x 156 mm perovskite-silicon tandem solar cells at the company’s industrial pilot line in Brandenburg an der Havel, Germany.

Oxford PV’s perovskite-silicon tandem solar cell technology is a two-terminal design. This approach will support the ease of integration into module fabrication and photovoltaic systems and eliminates the additional materials, weight and power invertor challenges of four-terminal tandem cells.

Oxford PV has had a close working relationship with Professor Snaith’s (Oxford PV Co-Founder and Chief Scientific Officer) research group at the University of Oxford, since Oxford PV was established in 2010. In January 2018, Oxford PV announced its collaboration with HZB, the leading center in Germany focused on perovskite-based multijunction solar cells, concentrated in its PVcomB and HySPRINT labs, headed by Professor Schlatmann and Professor Rech.