Advancing solar cell efficiency: insights from cesium lead halide perovskite analysis

In this study, we investigated the performance of cesium lead halide perovskite solar cells through numerical simulations using a Solar Cell Capacitance Simulator (SCAPS). Three cell configurations are proposed: Yb/ZnO/CsPbI₃/CuI/Au, Sm/TiO₂/CsPbBr₃/CuO₂/Au, and Yb/TiO₂/CsPbCl₃/CuO₂/Au. The solar cell was optimized by adjusting parameters such as the active layer thickness, hole transport layer (HTL), electron transport layer (ETL), metal work function (WF), defects, doping levels, series resistance (R_S), and shunt resistance (R_Sh). These studies indicate that photovoltaic performance is strongly influenced by critical factors, including the quality of the ETL and HTL layers, metal work function, series and shunt resistances, defect density, as well as the thickness and doping concentration of the absorber layers. The efficiencies of CsPbX₃ (X = I, Br, and Cl)-based perovskite solar cells were 26.68%, 16.76%, and 14.97%, respectively. The cells based on CsPbCl₃ and CsPbBr₃ exhibited superior stability, while the external quantum efficiency (EQE) measurements revealed that the CsPbI₃ cell responded across the entire visible and near-infrared spectrum, indicating its higher potential for photovoltaic applications compared to CsPbBr₃ and CsPbCl₃. In conclusion, we found that for diffusion lengths (L) greater than ~ 600 nm, the reduction in the internal electric field in CsPbBr₃ and CsPbCl₃ cells promotes electron–hole recombination within the core layers.