Exploring the photovoltaic potential of CsSbCl₄ Dion Jacobson Perovskites through first-principle calculations and SCAPS simulations

This work presents a comprehensive computational investigation of lead (Pb)-free CsSbCl₄ Dion–Jacobson (DJ)-based perovskite solar cells (PSCs), combining density functional theory (DFT) and Solar Cell Capacitance Simulator (SCAPS 1-D) device simulations. The electronic and optical properties of CsSbCl₄ were evaluated using two different exchange–correlation functionals, PBE-GGA and TB-mBJ. Notably, the band structure displays a direct bandgap of 1.395 eV with TB-mBJ, closely aligned with the Shockley–Queisser (SQ) limit, indicating the material’s suitability for high-performance photovoltaics. Projected density of states (PDOS) analysis revealed Sb s-states dominate the valence band (VB), and Sb 5p-states dominate the conduction band (CB), highlighting the central role of antimony in governing electronic transitions, while absorption spans the electromagnetic spectrum from UV to near IR, with a high absorption coefficient around 10⁵ cm⁻¹, ensuring efficient light harvesting. To optimize the solar cell architecture, key parameters were systematically tuned using SCAPS 1-D, including the selection of electron transport layer (ETL) and hole transport layer (HTL), absorber layer (AL) thickness, doping concentration (N_A), and defect density (Nt) were varied to enhance device output. Further, the influence of external conditions like series resistance (Rs), shunt resistance (Rsh), operating temperatures (300–400 K), and solar irradiance on photovoltaic performance was rigorously investigated. After careful optimization, the simulated device achieved a high short-circuit current density (J_SC) of 30.34 mA/cm², an open-circuit voltage (V_OC) of 1.04 V, a fill factor (FF) of 85.17%, and a power conversion efficiency (PCE) of 26.95%. Altogether, these findings not only underscore the potential of CsSbCl₄ perovskite as a promising non-toxic Pb-free alternative but also provide a viable route toward the realization of high-efficiency next-generation photovoltaics.