General Decomposition Pathway of Organic–Inorganic Hybrid Perovskites through an Intermediate Superstructure and its Suppression Mechanism
Shulin Chen, Ying Zhang, Xiaowei Zhang, Jinjin Zhao, Zewen Zhao, Xiao Su, Ze Hua, Jingmin Zhang, Jian Cao, Jicai Feng, Xiao Wang, Xin-Zheng Li, Junlei Qi, Jiangyu Li, Peng Gao
Abstract
Abstract Organic–inorganic hybrid perovskites (OIHPs) have generated considerable excitement due to their promising photovoltaic performance. However, the commercialization of perovskite solar cells (PSCs) is still plagued by the structural degradation of the OIHPs. Here, the decomposition mechanism of OIHPs under electron beam irradiation is investigated via transmission electron microscopy, and a general decomposition pathway for both tetragonal CH 3 NH 3 PbI 3 and cubic CH 3 NH 3 PbBr 3 is uncovered through an intermediate superstructure state of CH 3 NH 3 PbX 2.5 , X = I, Br, with ordered vacancies into final lead halides. Such decomposition can be suppressed via carbon coating by stabilization of the perovskite structure framework. These findings reveal the general degradation pathway of OIHPs and suggest an effective strategy to suppress it, and the atomistic insight learnt may be useful for improving the stability of PSCs.