In-Depth Analysis of Electron and Hole Transport Layers for Enhancing Ca3PI3 Solar Cell Efficiency through Advanced Numerical Simulation

This study investigates lead-free calcium–phosphorus iodide (Ca3PI3) perovskite solar cells with various electron transport layers (ETLs) like TiO2 and SnS2 and hole transport layers (HTLs) such as CuO, MoO3, P3HT, Sb2S3, CuSbS2, and GeSe. The ideal HTL, MoO3, was chosen, and its performance was simulated by using the SCAPS-1D tool. Two device structures were analyzed: device-I (Al/FTO/TiO2/Ca3PI3/MoO3/Ni) and device-II (Al/FTO/SnS2/Ca3PI3/MoO3/Ni). Various parameters were carefully optimized to achieve the best device performance, including donor and acceptor densities, defect density, thickness, series and shunt resistances, generation-recombination dynamics, current density (IV), quantum efficiency (QE%), and temperature. The top-performing device-I achieved a power conversion efficiency (PCE) of 29.02%, with a VOC of 1.288 V, a JSC of 25.235 mA/cm2, and a fill factor (FF) of 89.26%. Device II showed a PCE of 26.47%, with a VOC of 1.2486 V, JSC of 25.233 mA/cm2, and FF of 84.01%. These results emphasize the promise of device-I for high-performance Ca3PI3-based photovoltaic applications.