Muhaiminul Islam, Prasanjit Das, Md Farhan Imtiaz Chowdhury, Wasif Sadman Tanim, Md Fahim Sadat Bari, Md. Shaib Hossain
This study employs advanced SCAPS-1D simulation to enhance the performance of lead-free FASnI₃ perovskite solar cells (PSCs) by integrating non-traditional charge transport materials. A novel device architecture, FTO/ZnO (ETL)/FASnI₃/CBTS (HTL)/Au, with limited prior investigation, is systematically optimized by tuning key parameters including absorber thickness, defect density (Nt), acceptor density (NA), bandgap (Eg), electron affinity (χ), and back-contact work function. Optimization elevates the power conversion efficiency (PCE) from 27.09% to 29.06%, primarily due to an increase in short-circuit current density (Jsc) from 26.54 mA/cm² to 30.68 mA/cm², despite slight reductions in open-circuit voltage (Voc) (1.170 V to 1.129 V) and fill factor (FF) (87.24% to 83.92%). The ZnO/CBTS-based configuration demonstrates superior potential over conventional transport layers. These findings validate FASnI₃ as a high-performance, eco-friendly alternative to toxic lead-based perovskites and silicon and highlight ZnO and CBTS as promising low-research-burden materials. This work offers valuable insights for the design of efficient, stable, scalable, and commercially viable lead-free PSCs, contributing to the advancement of sustainable global energy solutions.