Synthesis of Cs + -Tuned (PEA) 2 PbI 4 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) 2 PbI 4 hybrid perovskite film was prepared by a one-step spin-coating method at room temperature. Based on the synthesis of (PEA) 2 PbI 4 , 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) 2 PbI 4 film and Cs + -doped (PEA) 2 PbI 4 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) 2 PbI 4 phase, a quasi-2D structure with two layers of [PbI 6 ] 4− -octahedron forms in Cs + -doped (PEA) 2 PbI 4 perovskite films, which is ascribed to the phase rearrangement of the (PEA) 2 PbI 4 crystal structure under the induction of Cs + ions.