Boosting efficiency above 28% using effective charge transport layer with Sr₃SbI₃ based novel inorganic perovskite

Strontium antimony iodide (Sr₃SbI₃) is one of the emerging absorbers materials owing to its intriguing structural, electronic, and optical properties for efficient and cost-effective solar cell applications. A comprehensive investigation on the structural, optical, and electronic characterization of Sr₃SbI₃ and its subsequent applications in heterostructure solar cells have been studied theoretically. Initially, the optoelectronic parameters of the novel Sr₃SbI₃ absorber, and the possible electron transport layer (ETL) of tin sulfide (SnS₂), zinc sulfide (ZnS), and indium sulfide (In₂S₃) including various interface layers were obtained by DFT study. Afterward, the photovoltaic (PV) performance of Sr₃SbI₃ absorber-based cell structures with SnS₂, ZnS, and In₂S₃ as ETLs were systematically investigated at varying layer thickness, defect density bulk, doping density, interface density of active materials including working temperature, and thereby, optimized PV parameters were achieved using SCAPS-1D simulator. Additionally, the quantum efficiency (QE), current density-voltage (J-V), and generation and recombination rates of photocarriers were determined. The maximum power conversion efficiency (PCE) of 28.05% with J_SC of 34.67 mA cm^-2, FF of 87.31%, V_OC of 0.93 V for SnS₂ ETL was obtained with Al/FTO/SnS₂/Sr₃SbI₃/Ni structure, while the PCE of 24.33%, and 18.40% in ZnS and In₂S₃ ETLs heterostructures, respectively. The findings of this study contribute to in-depth understanding of the physical, electronic, and optical properties of Sr₃SbI₃ absorber perovskite and SnS₂, ZnS, and In₂S₃ ETLs. Additionally, it provides valuable insights into the potential of Sr₃SbI₃ in heterostructure perovskite solar cells (PSCs), paving the pathway for further experimental design of an efficient and stable PSC devices.