Scientists Achieve Record Efficiency Level in Tandem Solar Cells

Scientists at the King Abdullah University of Science and Technology (KAUST) in Saudi Arabia have achieved a new record level of efficiency for solar cells. The team combined two different materials, crystalline silicon and perovskite, to create a tandem solar cell that reached an efficiency level of 33.2 percent. This is an improvement from the previous record of 32.5 percent.

Solar panels can use several different materials, each with their own unique properties and efficiency levels. The KAUST researchers combined the more common and cheaper crystalline silicon material with the more efficient but less reliable perovskite material. Efficiency is measured as power conversion efficiency (PCE), where all the available sunlight is converted into electricity with nothing lost.

Working Towards Renewable Energy Goals

The new tandem cell works to record-breaking levels partly because the top perovskite material absorbs blue light best, while the lower silicon material absorbs red light best. This spectrum coverage means more of the available sunlight can be captured and converted. Although the technology is not yet ready for commercial use, the KAUST team is continuing to work on improving the working lifespan of the cell and its size, which have traditionally been issues with perovskite.

The record was verified by the European Solar Test Installation (ESTI). Materials scientist Stefaan De Wolf from KAUST said, “This new record is the highest PCE of any two-junction solar cell under non-concentrated light, attesting the tremendous promise of perovskite/silicon tandems to deliver ultra-high performance photovoltaic modules, which is critical to rapidly achieve renewable energy goals towards combating climate change.”

Different types of solar cells have different efficiency records. Scientists have achieved an impressive 47.1 percent efficiency with a cell of six layers rather than two, but sunlight must be concentrated to reach that level. More materials mean more complexity for manufacturers, but progress is heading in the right direction. Hopefully, solar energy will play an ever-increasing role in green energy production.