Numerical Optimization of CsₓFA₁₋ₓPbI₃-Based Perovskite Solar Cells Using SCAPS-1D

This study presents a comprehensive numerical investigation of CsₓFA₁₋ₓPbI₃-based perovskite solar cells (PSCs) using the SCAPS-1D simulation software. A previously reported device architecture was first simulated to validate the model, yielding a power conversion efficiency (PCE) of 11.8%, closely matching experimental data. Following validation, key parameters were systematically optimized, including absorber thickness, defect density (Nt), and transport layers materials. The results indicate that an optimal absorber thickness in the range of 1000–1200 nm provides a balance between enhanced light absorption and efficient carrier collection. The N _t in the absorber layer was found to have a critical impact on device performance, with substantial degradation observed for densities above 10 ¹⁶ cm ^− 3 due to non-radiative recombination. Furthermore, alternative transport layers were evaluated. Among the seven electron transport layers (ETLs) and five hole transport layers (HTLs) examined, the combination of C₆₀ and NiO yielded the highest simulated PCE of 18.29%, attributed to favorable band alignment and reduced interfacial losses. These results emphasize the importance of optimizing both absorber quality and interfacial materials in designing high-efficiency PSCs. The insights gained from this work provide valuable guidelines for experimental efforts aimed at the development of next-generation perovskite solar cells.