We have investigated the structural, electrical and optical properties of cubic CsSnClBrI through first principle methods of density functional theory. The threshold cut-off for energy convergence conditions is taken as 1 x 10 \(^{-6}\) Ry. We investigate the cubic structural form of CsSnClBrI perovskite compound and its other electronic and physical properties as reported by the similar lead-free perovskites compounds of CsSnCl \(_3\) , CsSnBr \(_3\) , and CsSnI \(_3\) . The orthorhombic structural form of CsSnClBrI compound has also been reported in the literature. The bandgap result obtained for our studied compound is 0.72 eV using GGA-PBE and 0.9732 eV using the hybrid functional of exchange correlation function (HSE06). The optical properties of CsSnClBrI have been studied using DFT in the GGA PBE phase approximation. The computed refractive index of CsSnClBrI is 1.32, which is very near those of water. The optical absorption coefficient is also observed to be significantly in the ultraviolet (UV) region. In contrast to the out-of-plane (E \(\perp \) Z) direction, the in-plane (E \(\parallel \) X) direction of polarizations is shifted towards the greater photon energy based on optical characteristics. The optical characteristics graph shows anisotropic behavior since the polarizations along the in-plane and out-of-plane are different. The study’s findings suggest that CsSnClBrI may be a promising material for PSCs, including deep UV emitters and detectors.
