Numerical Investigation of Performance in MAPI1−xClx Perovskite Solar Cells Employing Hybrid Electron Transport Layers

In this work, a numerical study was carried out to analyze the impact of hybrid electron transport layers (h-ETLs) on the performance of MAPI1−xClx perovskite solar cells (PSCs) using the SCAPS-1D simulation software. Various h-ETL architectures, including PCBM-SnS2, TiO2-SnO2, PCBM/PCPB, and TiO2/ZnO, were investigated in order to optimize charge extraction and reduce recombination losses. The results indicate that the TiO2-SnO2 configuration exhibits the best optoelectronic performance, owing to favorable energy band alignment and enhanced electron transport properties. Parametric analysis reveals that an optimal absorber thickness of approximately 450 nm and an h-ETL thickness of about 30 nm lead to maximum power conversion efficiency. Furthermore, the investigation of defect density effects highlights that device performance is strongly dependent on defect states within the absorber layer, with defect densities below 1015 cm−3 resulting in significant improvements in short-circuit current density, open-circuit voltage, and overall efficiency. These findings emphasize the critical role of defect control in the development of high-efficiency and improved-stability perovskite solar cells.