Oxford Photovoltaics, in collaboration with Helmholtz-Zentrum Berlin (HZB) and the Photovoltaics and Optoelectronics Device Group at the University of Oxford, produced a 1 cm2 perovskite-silicon two-terminal tandem solar cell with a verified conversion efficiency of 25.2%. The two-terminal tandem solar cell efficiency was certified by the Fraunhofer Institute for Solar Energy Systems ISE.

Oxford PV and HZB develop a simplified perovskite tandem solar cell image

Dr Chris Case, Chief Technology Officer at Oxford PV commented, “The unique, optically enhanced architecture developed as part of this collaboration, minimizes 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.”

The two-terminal design is intended to simplify the integration into PV module fabrication, compared to four terminal architectures often used in scientific research, eliminating additional materials, weight and power invertor challenges found in four-terminal tandem cells.

Oxford PV and HZB announced the start of this collaboration initiative in January 2018.