Numerical Investigation of CsGeI3 Perovskite Solar Cells Employing PANI-Doped Graphene Oxide as a Hole Transport Layer

Perovskite solar cells (PSCs) have quickly emerged as strong contenders for future photovoltaic technologies, propelled by their outstanding and steadily improving power conversion efficiencies (PCEs). This work utilizes SCAPS-1D to examine and optimize a lead (Pb)-free PSC architecture. An environmentally friendly CsGeI3 absorber was incorporated into the device architecture, with polyaniline-doped graphene oxide (PANI:GO) as the HTL and WS2 functioning as the ETL. The use of PANI/GO as an HTL represents the primary contribution of this study, providing enhanced charge selectivity and conductivity. Systematic variation of HTL, ETL, and absorber layer thickness was carried out to identify the best device setup. The optimized structure FTO/WS2/CsGeI3/PANI:GO/Ag achieved a PCE of 30.8%, a Voc of 1.14 V, a Jsc of 31.3 mA/cm2, and an FF of 86.4%. These results offer a feasible and eco-friendly pathway toward high-performance Pb-free PSCs, offering important insights that can drive future progress in device engineering and materials development.