Achieving 22% efficiency by exploring lead-free Novel KSnI ₃ perovskite solar cells with multiple charge transport layers

Nontoxic, lead-free perovskites have gained significant attention in recent years due to their potential environmental benefits. This numerical study investigates the application of a novel perovskite material, KSnI 3 , as the absorber layer in solar cell devices due to its high absorption coefficient in the visible photon energy range. Four different electron transport layers (ETLs), including CdZnS, PC[Formula: see text]BM, SnS 2 and SrTiO 3 (STO), along with ten different hole transport layers (HTLs), including PTAA, CNTS, C 6 PcH 2 , MoO 3 , MoS 2 , C6TBTAPH 2 , GaAs, TiO 2 , Cu 2 Te and D-PBTTT-14, are investigated to develop various distinct combinations. The study begins by optimizing the HTL, after which four distinct combinations using the selected HTLs and the ETLs were made for further numerical analysis. Several device parameters, including HTL acceptor density, absorber layer thickness, defect density and donor density, were optimized to enhance device efficiency. Following optimization, the device configuration of FTO/PC[Formula: see text]BM/KSnI 3 /D-PBTTT-14/Au was identified as the champion, with a power conversion efficiency (PCE) of 22.28%, an open-circuit voltage ([Formula: see text] of 1.382[Formula: see text]V, a short-circuit current density ([Formula: see text] of 18.435[Formula: see text]mA/cm 2 and a fill factor (FF) of 87.44%. Additionally, the effects of temperature, series resistance, shunt resistance, generation and recombination rates, JV characteristics, capacitance, Mott-Schottky analysis and quantum efficiency (QE) are observed following the device parameter optimization. These significant findings from this theoretical study are expected to guide future experimental research on KSnI 3 perovskite, potentially leading to the development of KSnI 3 -based perovskite solar cells.