Intrinsic stability analysis of perovskite nanopowder with double and triple cation in a site, FAxMA(1-x)PbI3 and FAxCsyMA(1-x-y)PbI3

Inorganic-organic hybrid perovskites are being widely studied due to their interesting optical and electronic properties, although certain stability-related problems have previously been reported. For obtaining ABX₃-type inorganic-organic hybrid perovskites with a crystalline structure stable over time and optimized band gap values for photovoltaics, this study presents the synthesis and characterization of hybrid perovskite nanopowders in which the A site is occupied by two or three cations (FA_xMA_(1-x)PbI₃ and FA_xCs_yMA_(1-x-y)PbI₃). DR-UV–vis spectroscopy was used to study the time evolution of the optical properties. X-ray diffraction was applied to study the evolution of the crystallinity of the nanopowders synthesized. Among all the perovskites synthesized, FA_0.1MA_0.9PbI₃ and FA_0.1Cs_0.1MA_0.8PbI₃ showed cubic crystalline structure that remained stable over time and optical band gap values of 1.48 eV and 1.47 eV, respectively. Therefore, with A-site doping, it was possible to synthesize perovskite nanopowders with an enhanced structure and improved optical properties with regard to MAPbI₃ perovskite.