Infrared light sensitive Sn/Pb binary perovskite solar cells with improved stability in air and organic amine-free perovskite solar cells with improved stability against light exposure

We found that the Sn halide perovskite became stable in air when Pb halide perovskite was added. In this report we discuss photovoltaic performances for the binary MASnPbI (MA:methylammonium) perovskite solar cells (4.2% efficiency) with gradient structure from the bottom to the top. In addition, we also reported organic amine free-CsPbI solar cells with about 2-4 % efficiency. Urbach energy measurement suggested that lowering defect density of the binary MASnPbI and CsPbI perovskite solar cells are needed for enhancing the efficiency.