Theoretical Prediction of the Physical Properties of Novel Fluoro-Perovskites \({\textrm{InXF}}_{3}\hbox {(X = Sn, Pb)}\) for Advanced Optoelectronic and Thermoelectric Applications Using DFT Calculations

The need for environmental friendly and sustainable energy sources is increasing day by day. This study highlights the structural, mechanical, optoelectronic and thermoelectric properties of cubic perovskites \({\textrm{InXF}}_{3}\hbox {(X = Sn, Pb)}\) using Density functional theory based ab initio calculations. We used Generalized Gradient Approximation of Perdew-Burke-Ernzerhof functional to obtain the optimized structural features of these compounds. The lattice constant of \({\textrm{InSnF}}_{3}\) and \({\textrm{InPbF}}_{3}\) is 4.73 Å  and 4.85 Å,  respectively. The stability of these compounds is verified from Born-Huang stability criteria. The elastic constants are used to extract bulk modulus, young’s modulus, shear modulus, Poisson’s ratio, Pugh’s ratio and other important mechanical parameters. For electronic properties calculations, we employed the correction of \( \textrm{r}^2 \)SCAN functional in addition to PBE-GGA technique. The band gap of \({\textrm{InSnF}}_{3}\) and \({\textrm{InPbF}}_{3}\) with PBE-GGA ( \( \textrm{r}^2 \)SCAN ) is 0.62 ( 0.95 ) and 1.71 ( 3.77 ) eV, respectively. The optical parameters like dielectric function, reflection and absorption are presented for the potential applications of these materials in optoelectronic industry. The thermoelectric analysis showed that the electrical conductivity and figure of merit increases with temperature and highlights the significance of these compounds for thermoelectric applications.