Enhanced Efficiency of Mixed-Halide Perovskite Solar Cells Through Optimization of the Layer Thicknesses, Defect Density, and Metal Contact Work Function

Mixed-halide perovskites enable the creation of high-performance and low-cost solar cells. Chloride incorporation enhances film morphology, carrier diffusion length, and stability, improving device performance. Nevertheless, optimizing film thickness, defect density, and metal contact work function remains insufficiently explored, despite its potential to enhance power conversion efficiency. In this study, a numerical simulation was performed using SCAPS-1D (version 3.3.10) to identify the optimal parameters for the FTO/TiO₂/CH₃NH₃Pb_3-xCl_x/Spiro-OMeTAD/Au configuration. The best performance parameters that have been published in the literature based on experimental results are as follows: <i>V_OC</i> = 1.077 V, <i>J_SC</i> = 21.45 mA/cm², <i>FF</i> = 77.57%, and <i>PCE</i> = 17.97%. In contrast, the performance parameters obtained from numerical simulations for the same structure are <i>V_OC</i> = 1.28 V, <i>J_SC</i> = 21.63 mA/cm², <i>FF</i> = 78%, and <i>PCE</i> = 21.53%. In our numerical analysis, we achieved efficiencies that were comparable to those reported in experimental studies, and after optimization, superior performance parameters were attained, including <i>V_OC</i> = 1.179 V, <i>J_SC</i> = 27.26 mA/cm², <i>FF</i> = 81.03%, and <i>PCE</i> = 26.07%. These results indicate that optimized parameters can be integrated into the design and fabrication of mixed-halide perovskite solar cells to enhance performance.