Enhancing the Performance of Lead‐Free Perovskite Solar Cells Through Interfacial Engineering and Doping of Charge Transport Layers

Lead‐free perovskite solar cells (PSCs) offer a sustainable alternative to lead‐based devices while maintaining high photovoltaic performance. In this study, CH ₃ NH ₃ SnI ₃ is used as the perovskite absorber, with zinc oxide (ZnO) as the electron transport layer (ETL) and copper oxide (CuO) as the hole transport layer (HTL). Simulations using SCAPS‐1D (Solar Cell Capacitance Simulator in One Dimension) show a power conversion efficiency (PCE) of 16.30% for the baseline structure without interfacial layers (IL) or doping. To improve performance, IL are introduced at the buried interfaces: graphene at the CuO/CH ₃ NH ₃ SnI ₃ interface and cubic silicon carbide (3C‐SiC) at the CH ₃ NH ₃ SnI ₃ /ZnO interface. This enhances charge transfer and reduces recombination losses, increasing the PCE to 19.01%. Further optimization is achieved by doping the transport layers with 3% Al in ZnO and 1% Ag in CuO, based on experimental values reported in the literature. These doping levels improve band alignment and charge extraction, leading to a maximum PCE of 20.24%. Overall, this study highlights the combined effect of interfacial engineering and controlled doping as effective strategies for improving the performance of eco‐friendly, lead‐free PSCs.