Optimization and Performance analysis of lead-free KSnBr3-based perovskite solar: A pathway to efficient and Eco-friendly sustainable photovoltaic technology

• Lead free KSnBr 3 based perovskite solar cells are simulated by SCAPS-1D software. • We have optimized the thicknesses, doping density, defect density of the absorber layer. • Optimized the capacitance and conductance for voltage on the cell performance. • The solar cell structure FTO/TiO 2 /KSnBr 3 /Cu 2 O/Au was proposed with maximum efficiency 29.07 %. Perovskite materials represent a leading avenue of scientific exploration for more efficient and cost-effective alternatives to conventional silicon-based devices. However, toxic lead components in perovskite solar cells have substantially impeded their commercial viability. This study addresses this issue by designing and optimizing a non-toxic, inorganic n-i-p planar architecture based on lead-free KSnBr 3 perovskite solar cells, selected for its promising optoelectronic properties, high stability, and non-toxicity compared to other lead-free alternatives such as tin- or bismuth-based perovskites. Using SCAPS-1D numerical simulations, we comprehensively analyze key photovoltaic parameters, including photoactive layer thickness, charge carrier defect densities, electron affinity, capacitance and conductance, and back contact metal selection. The simulation setup incorporates well-defined boundary conditions to ensure realistic modeling of device behavior. Our optimized KSnBr₃-based device achieves a V oc of 0.7323 V, J sc of 47.01 mA/cm², FF of 84.44%, and an impressive PCE of 29.07%, demonstrating its potential for high-performance solar energy conversion. While this study is based on numerical predictions, experimental validation is planned to confirm these findings and further refine material synthesis and device fabrication processes. Additionally, we discuss potential challenges in scaling up these results for large-area solar cell fabrication, addressing factors such as material deposition uniformity and interface engineering. Beyond performance, KSnBr 3 offers significant environmental and economic advantages over conventional silicon-based solar cells, including lower processing temperatures, reduced raw material costs, and improved sustainability in manufacturing. This work advances the field of lead-free perovskite solar cells, providing crucial insights for future experimental research and commercial applications in sustainable energy technologies.