Controlled Growth of Porous InBr3: PbBr2 Film for Preparation of CsPbBr3 in Carbon-Based Planar Perovskite Solar Cells

Due to the low solubility of CsBr in organic solvents, the CsPbBr3film prepared by the multi-step method has holes and insufficient thickness, and the light absorption capacity and current density of the perovskite film hinder the further improvement in the power conversion efficiency (PCE) of CsPbBr3solar cells. In this study, we introduced InBr3into the PbBr2precursor solution and adjusted the concentration of PbBr2, successfully prepared PbBr2with a porous structure on the compact TiO2(c-TiO2) substrate to ensure that it fully reacted with CsBr, and obtained the planar carbon-based CsPbBr3solar cells with high-quality perovskite film. The results reveal that the porous PbBr2structure and the increasing PbBr2concentration are beneficial to increase the thickness of the CsPbBr3films, optimize the surface morphology, and significantly enhance the light absorption capacity. Finally, the PCE of the CsPbBr3solar cells obtained after conditions optimization was 5.76%.