Device modeling and numerical analysis of lead-free MASnI3/Ca3AsI3 based perovskite solar cells with over 38% efficiency

Abstract

This research proposes an innovative model for perovskite solar cells (PSCs) that has the potential to significantly enhance the efficiency of PSC technology. The interest in perovskite absorbers in solar cells is increasing everyday due to its superior optical features, enhanced performance, lightweight characteristics, and cost efficiency. In this study, a double-absorber organic–inorganic PSC based on MASnI₃/Ca₃AsI₃ has been developed, using MASnI₃ as the upper-layer absorber and Ca₃AsI₃ as the lower-layer absorber. The primary objective of the research is to select appropriate materials for the hole transport layer (HTL), electron transport layer (ETL), and back-connect metal. We achieved significant results in the structure of FTO/SnS₂/MASnI₃/Ca₃AsI_3/CuO/Au by optimizing temperature, thickness, defect density, back contact work function, and the shallow acceptor density of the top absorber. Our proposed structure has achieved an open circuit voltage of 1.2559 V, a fill factor of 89.88 %, a short-circuit current of 34.3025 mA/cm², and a maximum power conversion efficiency (PCE) of 38.72 %. The device provides this optimal PV output at a temperature of 300 K, with a thickness of 0.860 µm for the MASnI₃ absorber and 0.350 µm for the Ca₃AsI₃ absorber. The materials used in this study are less toxic and more environmentally friendly compared to lead or other heavy materials, indicating a promising direction for sustainable PSC fabrication. Overall, this research paves the way for the development of new technologies and their successful implementation in various solar energy contexts, ensuring more effective and eco-friendly solutions for a brighter future.