Device Simulation of CsPbBr₃ Solar Cells for High‐Efficiency Blue Light Photovoltaic Power Converters

Abstract

The performance of CsPbBr3 solar cells is investigated using device simulation to clarify the criteria for obtaining high‐efficiency blue light photovoltaic power converters. The results show that the conduction band offset between the electron transport layer (ETL) and CsPbBr3 layer significantly impacts conversion efficiency. The best device performance is obtained when the conduction band of the ETL is 0.4 eV higher than that of the CsPbBr3 layer. Simulations also revealed that gallium nitride is preferred to conventional titanium oxide (TiO2) as the ETL material. The analysis indicates that the carrier diffusion length of the CsPbBr3 layer significantly affects the short‐circuit current density and fill factor of devices and that a carrier diffusion length of at least 0.5 μm is required to realize high‐efficiency devices. The use of a transparent conductive oxide layer with a work function smaller than 4.0 eV or the insertion of a buffer layer with electron affinity less than 4.1 eV can effectively improve the open‐circuit voltage of devices.