Excess PbI2 evolution for triple-cation based perovskite solar cells with 21.9% efficiency

The PSCs are prepared under two environments to explore the effect of excessive PbI 2 at initial days, which revealing excess and its evolution in perovskite thin films. • Triple-cation perovskites were glove box atmospheric environment. Defect passivation with days explored. PCE dramatically increase 21.68% 21.89% evolution. triple cation mixed (CsFAMA) known as one most efficient candidates for solar cells (PSCs). It is found that power conversion efficiency (PCE) triple-cation based devices would test time extending, maximum normally obtained after several aging storage. Here, relationship between enhanced device performance, films was systematically CsFAMA-PSCs by two-step methods environmental conditions, including ambient air (30% humidity). After 7 testing, conditions increased 12.4% 12.2%, reached 21.89%, respectively. At XRD peak intensities phase gradually decreased those corresponding increased. Along time-resolved photoluminescence (TRPL) kelvin probe force microscopy (KPFM), it defects passivated . This work reveals film, can further supplement understanding defect passivation.