An ab-initio insight computation of structural, electronic and optical properties of Na-doped CsSrF3 fluoro-perovskite for optoelectronic applications

[Display omitted] •CsSrF3 Fluoro-Perovskite has been investigated using Density Functional Theory (DFT).•Na-doping results in the reduction of band-gap.•CsSrF3 halide perovskite are found to be energetically, mechanically and dynamically stable.•The electronic analysis showed that the studied compound is semiconductor. Density functional theory computations were implemented on pure and Na-doped cubic CsSrF3 to investigate its structural, electronic and optical characteristics as a probable well-designed compound in the perovskite family. Pure material optimization resulted in a lattice parameter of 4.83 Å, which is in superb covenant with the reported value. Doping CsSrF3 with varying amounts of sodium resulted in cubic phase alteration into pseudo-cubic tetragonal. The direct bandgap of pure CsSrF3 was measured to be 5.66 eV. The band gap was slightly shrunk as a result of changes in sodium concentration. Doping CsSrF3 with Na at Cs sites not only modifies the material's electronic properties, but also its optical ones. Changes were made to both the refractive index and the pure dielectric function. The theoretical foundation laid by this fluoride-type material can be used to inform the development of next-generation, high-performance ABX3-type optoelectronic materials.