Fraunhofer ISE and Oxford PV Achieve World Record Efficiency with Tandem Solar Module

A research collaboration between Fraunhofer Institute for Solar Energy Systems ISE and Oxford PV has yielded a groundbreaking achievement in the realm of photovoltaic (PV) technology. The team has successfully produced a PV module utilizing perovskite silicon tandem solar cells from Oxford PV, setting a new world record for efficiency.

The PV module boasts an impressive efficiency of 25 percent and delivers an output of 421 watts on an area of 1.68 square meters, establishing itself as the world’s most efficient silicon perovskite tandem solar module in an industrial format. Leveraging equipment at Fraunhofer ISE’s Module-TEC, the researchers optimized the manufacturing processes for the tandem technology, utilizing equipment already employed in mass production.

Oxford PV, known for its expertise in perovskite-silicon solar cells, has been producing these cells in M6 format with an efficiency of 26.8 percent in small series at its facility in Brandenburg, Germany. The commercial production of tandem solar cells is slated to commence this year. David Ward, Chief Executive Officer of Oxford PV, emphasizes the significance of this achievement, stating that it underscores the potential of tandem solar cells to deliver record-breaking performance when integrated into solar panels.

Perovskite silicon tandem cells exhibit a theoretical maximum efficiency exceeding 43 percent, surpassing the efficiency of traditional silicon solar cells, which typically fall below 30 percent. The successful integration of these cells into a glass-glass tandem PV module with 25 percent efficiency marks a significant milestone for the PV industry. Prof. Dr. Stefan Glunz, Head of Photovoltaics at Fraunhofer ISE, highlights the potential of tandem technology for industrial-scale PV production.

Addressing the challenges posed by the temperature sensitivity of the perovskite layer, the research team developed low-temperature processes for interconnection and encapsulation, ensuring compatibility with industrial mass production. Dr. Achim Kraft, Group Leader for Interconnection Technology at Fraunhofer ISE, underscores the scalability of these processes for implementation in existing PV production lines.

To validate the efficiency of the tandem module, precise calibration measurements were conducted using advanced multispectral solar simulation techniques. The teams are now focused on certifying the PV module, conducting intensive tests on long-term stability to ensure its reliability and durability.

The collaboration between Fraunhofer ISE and Oxford PV heralds a new era in solar technology, paving the way for high-efficiency, commercially viable tandem solar modules with significant potential to drive the global transition towards sustainable energy.