Researchers at The University of Toledo (UT) in the US have developed an all-perovskite tandem solar cell with excellent conversion efficiency. The new kind of device combines two different cells to harvest different parts of the solar spectrum, resulting in increased total electrical power generated.

The team's process enables the fabrication of bottom cells using mixed Sn-Pb perovskite absorbers. The fabrication of the efficient bottom cell, which the researchers say had not been accomplished before, is what is truly innovative about this research work. “Our all-perovskite solar cells have the so-called four-terminal structure, which stacks a wide-band-gap top cell with a low-band-gap bottom cell. The current all-perovskite tandem cells are limited by the lack of efficient bottom cell”.