Numerical analysis and device modelling of a lead-free Sr3PI3/Sr3SbI3 double absorber solar cell for enhanced efficiency

Abstract

Halide perovskites are the most promising options for extremely efficient solar absorbers in the field of photovoltaic (PV) technology because of their remarkable optical qualities, increased efficiency, lightweight design, and affordability. This work examines the analysis of a dual-absorber solar device that uses Sr₃SbI₃ as the bottom absorber layer and Sr₃PI₃ as the top absorber layer of an inorganic perovskite through the SCAPS-1D platform. The device architecture includes ZnSe as the electron transport layer (ETL), while the active layer consists of Sr₃PI₃ and Sr₃SbI₃ with precise bandgap values. The bandgap value of Sr₃SbI₃ is 1.307 eV and Sr₃PI₃ is 1.258 eV. By employing double-graded materials of Sr₃PI₃/Sr₃SbI₃, the study achieves an optimized efficiency of up to 34.13% with a V_OC of 1.09 V, FF of 87.29%, and J_SC of 35.61 mA cm⁻². The simulation explores the influence of absorber layer thickness, doping level, and defect density on electrical properties like efficiency, short-circuit current, open-circuit voltage, and fill factor. It also examines variations in temperature and assesses series and shunt resistances in addition to electrical factors. The simulation's output offers valuable insights and suggestions for designing and developing double-absorber solar cells.