A groundbreaking achievement in solar energy research has been unveiled as scientists from the Fraunhofer Institute for Solar Energy Research ISE and NWO-Institute AMOLF (Amsterdam) jointly created a multijunction solar cell with an unprecedented efficiency rate of 36.1%. This remarkable milestone marks the highest efficiency ever achieved for a solar cell based on silicon. The team presented their groundbreaking achievement at the European Photovoltaic Solar Energy Conference (EU PVSEC) held in Lisbon on September 21, 2023. The research project received funding through the Fraunhofer ICON program.
Albert Polman, who spearheaded the AMOLF segment of the project, highlighted the unique collaboration between Fraunhofer ISE and AMOLF, which began in 2020. Fraunhofer ISE is renowned for its work on ultra-high efficiency solar cells using silicon and III-V semiconductors, while AMOLF has extensive expertise in optimizing light management within solar cells. This collaboration allowed them to achieve an efficiency record that was previously unimaginable.
Frank Dimroth from Fraunhofer ISE emphasized that the breakthrough was a result of combining the best processes available from both teams. Their achievement overcame the fundamental limitation of photovoltaic energy conversion efficiency in silicon-based solar cells, which was capped at 29.4%. This limitation was surpassed by creating a “multijunction” solar cell, which involves stacking multiple light-absorbing layers to efficiently harness various parts of the sunlight’s color spectrum.
The record-breaking solar cell combines a cutting-edge “silicon TOPCon” solar cell with innovative high-efficiency cell designs developed at Fraunhofer ISE. It also incorporates two semiconductor layers made of gallium indium phosphide (GaInP) and Gallium Indium Arsenide Phosphide (GaInAsP), both developed at Fraunhofer ISE. Additionally, a specially designed metal/polymer nanocoating crafted at AMOLF and Fraunhofer ISE enhances light trapping within the cell, pushing the efficiency beyond 36%.
While these ultra-high-efficiency solar cells are currently more costly to manufacture than conventional silicon solar cells (which typically achieve up to 27% efficiency), their exceptional performance makes them highly attractive for applications where space is limited, such as solar-powered electric cars, consumer products, and drones. Moreover, the novel light management design has broader applications, including silicon-perovskite multijunction solar cells, promising a brighter future for renewable energy technologies.