Device Optimization of CsGeI 2 Br Perovskite Solar Cell With Enhanced Efficiency of 25.76%

In recent years, there has been a surge of interest in inorganic metal halide perovskite materials, driven by their demonstrated potential in solar energy applications. Among these materials, CsGeI 2 Br, a cesium‐based perovskite, has emerged as particularly promising due to its direct band gap, optical conductivity, high light absorption coefficient, as well as its eco‐friendly and lead‐free composition. The present study focuses on a lead‐free single‐junction perovskite solar cell with the device architecture Ag/MoO 3 /CsGeI 2 Br/ZnO/FTO, utilizing SCAPS‐1D for comprehensive simulation. Notably, CsGeI 2 Br serves as the absorber layer in the cell. The investigation systematically explores the impact of thickness, defect density, interface defect density, and a synergistic effect of absorber defect density and operating temperature on critical output parameters, including efficiency, open‐circuit voltage, short‐circuit current, and fill factor. Simulation data indicates a clear correlation, showing an increase in JV parameters with the thickness of the absorber layer and a decrease in J – V parameters with an increase in defect density and temperature. The cell achieves maximum efficiency, reaching an impressive 25.76%, after optimization of various parameters. The observed stability in fill factor serves as an indicator of the overall cell stability, underscoring the potential of CsGeI 2 Br for advanced lead‐free perovskite solar cell technologies.