Performance analysis for optimum design of lead-free MASnI₃ based perovskite solar cells with NiO_x and ZnO as charge transport layers

Abstract In this paper, we investigate the performance optimization of a novel perovskite solar cell (PSC) structure comprising lead-free methylammonium tin iodide (MASnI 3 ) active layer along with a unique charge transport layers (CTLs) material combination such as NiO x as the hole transport layer (HTL) and ZnO as the electron transport layer (ETL) at room temperature. Unlike traditional toxic lead-based perovskites, our proposed eco-friendly MASnI 3 -based PSC structure leverages inorganic CTLs to improve the structural stability and charge transport efficiency significantly. This design addresses key limitations such as recombination losses, thermal instability, and toxicity. The use of wider band gap CTLs ensures high optical transparency, and the favourable energy level alignments with the active layer contribute to the enhanced device overall performance and long-term cost-effectiveness. The simulated results are verified with experimental data taken from literature. The effects of several performance-defining structural parameters, such as the thickness of different layers, doping density, and defect density, are considered in the SCAPS-1D-based simulation. The results indicate the possibilities of some optimum designs for the best target performance. The design with optimized structural parameters of the perovskite absorber layer (PAL), HTL, and ETL yields a high-power conversion efficiency (PCE) of 33.46%. The optimized structure also achieves more than 90% quantum efficiency (QE) over a wide visible spectrum coverage (300–870 nm). Comparative analysis with recently published MASnI 3 -based PSCs having other inorganic CTLs combinations reveals the superiority of our proposed NiO x and ZnO-based alternative PSC architecture. Variations of fill factor (FF), open-circuit voltage (V OC ), short-circuit current density (J SC ), and quantum efficiency (QE) are also investigated.