Effects of Cesium/Formamidinium Co-Addition to Perovskite Solar Cells

In this study, the stabilities and conversion efficiencies of perovskite solar cells including cesium (Cs) or formamidinium (FA) at the CH₃NH₃ site were investigated. The additive effects on the photovoltaic properties and crystalline structures were investigated via current–voltage measurements, X-ray diffraction, and scanning electron microscopy. The simultaneous co-addition of Cs and FA to the CH3NH3PbI3 perovskite crystal improved the photovoltaic properties, which may be due to the suppression of the decomposition of the perovskite crystals and the promotion of crystal growth.