Design and simulation of high efficiency KSnI3 based perovskite solar cells using DFT and SCAPS-1D.

This study presents a novel KSnI3-based heterostructure solar cell design, incorporating efficient electron transport layers (ETLs) such as CeO₂, and hole transport layers (HTLs) based on CBTS. Using Density Functional Theory (DFT), the electrical and optical properties of KSnI3 are characterized and implemented in SCAPS-1D to model the proposed solar cell. The numerical analysis demonstrates that the ITO/CeO2/KSnI3/CBTS/Ag structure achieves significant photo-conversion efficiency. Key factors such as KSnI3 layer thickness, series resistance, light conversion efficiency, and operating temperature are investigated to optimize performance. Additionally, the influence of ETL and absorber thickness, defect density, and electron affinity are examined. The simulation results show strong agreement with both numerical and experimental data, yielding an optimized open-circuit voltage (VOC) of 0.86 V, a short-circuit current density (JSC) of 21.5 mA/cm2, a fill factor (FF) of 86.05%, and an enhanced power conversion efficiency (PCE) that increased from 11.3 to 13.46% at a KSnI3 thickness of 1.4 μm, under a defect density of 1014 cm-3 and an electron affinity of 3.44 eV. This comprehensive simulation offers valuable insights that can guide further research on KSnI₃-based solar cells.