A Numerical Strategy for Achieving Efficiency Exceeding 32% with a Novel Lead‐Free Dual‐Absorber Solar Cell Using Ca3SbI3 and Sr3SbI3 Perovskites

Abstract

This study presents a numerical approach to achieve high efficiency using a novel dual‐absorber perovskite solar cell (PSC) utilizing environmentally friendly inorganic perovskite materials focusing on the optimization of different parameters. Ca3SbI3 and Sr3SbI3 are employed as the upper and lower absorber layer, respectively, in the proposed PSC structure. The device architecture also incorporates SnS2 as the electron transport layer (ETL) and Spiro‐OMeTAD as the hole transport layer (HTL). The further investigation explores the effect of ETL and HTL thicknesses and doping concentrations on device performance, revealing significant impact on photovoltaic parameters. Using double‐graded materials of Ca3SbI3/Sr3SbI3 with ETL and HTL, the PSC in this study achieves an optimized efficiency of 32.74% with JSC of 34.17 mA cm−2, fill factor of 83.77%, and VOC of 1.14 V having an optimized level of doping 1 × 1017 cm−3 for Sr3SbI3 and 1 × 1016 cm−3 for Ca3SbI3 perovskite materials, with a thickness of 800 and 200 nm for Sr3SbI3 and Ca3SbI3, respectively, and defect density of 1 × 1012 cm−3 for both the materials at room temperature. These findings provide a blueprint for developing highly efficient and cost‐effective PSCs, emphasizing the importance of dual‐absorber configurations in surpassing limit of efficiency of single‐junction solar cells.