Synthesis of Cs+-Tuned (PEA)2PbI4 Perovskite Thin Films by One-Step Spin Coating

Abstract

As a candidate material for the next generation photovoltaic and light-emitting devices, organic-inorganic hybrid perovskite materials have attracted extensive attention. In this study, a (PEA)2PbI4 hybrid perovskite film was prepared by a one-step spin-coating method at room temperature. Based on the synthesis of (PEA)2PbI4, the inorganic Cs+ ions were doped in the film to investigate the influence of Cs+ doping on the structure and properties of two-dimensional (2D) perovskite film. The results show that both as-grown (PEA)2PbI4 film and Cs+-doped (PEA)2PbI4 film exhibit the instinct of the layered structure, though excess Cs+ ions doping would make the structure weakened. Through analyzing the optical properties, it is found that, besides the 2D (PEA)2PbI4 phase, a quasi-2D structure with two layers of [PbI6]4−-octahedron forms in Cs+-doped (PEA)2PbI4 perovskite films, which is ascribed to the phase rearrangement of the (PEA)2PbI4 crystal structure under the induction of Cs+ ions.