Development and theoretical investigation of antimony-based halide perovskite solar cell using kesterite as hole transport material

Cesium antimony iodide (Cs₃Sb₂I₉) is a lead-free halide perovskite attracting significant attention due to its tunable bandgap, unique optoelectronic properties, and potential as a light-absorbing material in perovskite solar cells (PSCs). Kesterite CZTSe, a stable, non-toxic, and cost-effective material that facilitates efficient hole extraction, reduces recombination, and is compatible with lead-free perovskites, is employed in this study as a novel hole transport layer (HTL) for high-performance, sustainable solar cells. The influence of various parameters on the device's performance with the general architecture of FTO/WS₂/Cs₃Sb₂I₉/CZTSe/Ag was investigated theoretically using SCAPS-1D numerical software. Optimization of the device yielded a notable power conversion efficiency (PCE) of 21.02% and a high fill factor (FF) of 81.94%, underpinned by a type-II band alignment that promotes efficient charge transport. The simulated quantum efficiency exceeded 95% across 300-650 nm, demonstrating excellent visible-light absorption. Temperature-dependent analysis indicated stable operation within 240-320 K, while open-circuit voltage (V_oc) increased sharply with acceptor density above 10²⁰ cm⁻³, reflecting enhanced built-in potential and reduced recombination. The results contained in this study are projected to advance knowledge towards the understanding of complex phenomena in emerging materials and technologies that could be beneficial for performance optimization in solar devices, thus, their future commercialization.