A Study of Inverted-Type Perovskite Solar Cells with Various Composition Ratios of (FAPbI(3))(1−x)(MAPbBr(3))(x)

This work presents mixed (FAPbI(3))(1−x)(MAPbBr(3))(x) perovskite films with various composition ratios, x (x = 0–1), which are formed using the spin coating method. The structural, optical, and electronic behaviors of the mixed (FAPbI(3))(1−x)(MAPbBr(3))(x) perovskite films are discussed. A device with structure glass/indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)/mixed perovskite/C(60)/BCP/Ag was fabricated. The mixed perovskite film was an active light-harvesting layer. PEDOT:PSS was a hole transporting layer between the ITO and perovskite. Both C(60) and bathocuproine (BCP) were electron transporting layers. MAPbBr(3) was added to FAPbI(3) with a composition ratio of x = 0.2, stabilizing the perovskite phase, which exhibited a uniform and dense morphology. The optimal device exhibited band matching with C(60), resulting in a low series resistance (R(sh)) and a high fill factor (FF). Therefore, the device with composition (FAPbI(3))(1−x)(MAPbBr(3))(x) and x = 0.2 exhibited outstanding performance.