Thermally stable and efficient CsF-doped All-Inorganic CsPbIBr2 perovskite solar cells exceeding 15% PCE

Different strategies such as interface modification, cell encapsulation, perovskite doping, etc., are employed to address the different types of stability issues in perovskite solar cells. In this research, we used cesium fluoride (CsF) as a doping material to optimize the formation of CsPbIBr2 film and investigate its effect on the thermal stability of the devices. Our findings show that CsF diffuses into CsPbIBr2 seed film successfully and greatly enhances the stability of perovskite solar cells under study. Furthermore, compared to the reference device without doping, CsF-doped devices were found to have reduced trap state density, suppressed recombination of carriers, enhanced crystallinity, and improved power conversion efficiency from 13.15 to 15.54%. The study provides important pathways to fabricate highly stable perovskites thin films for all-in-organic solar cells.