Exploring the Optoelectronic Potential of M2SnX3F2 (M = Sr, Ba; X = S, Se) Compounds Through First-Principles Analysis of Structural, Electronic, and Optical Properties

Abstract

In this study, the equilibrium ground-state, electronic structure, and optical properties of four chalcofluorides, M2SnX3F2 (M = Sr, Ba and X = S, Se) compounds have been reported using the density functional theory (DFT) based on the generalized gradient approximation (GGA-PBE) functional. The non-covalent interactions have been considered using the dispersion-corrected theory (DFT + D3). The electronic bond structures have shown that the studied compounds are direct semiconductors. Calculated optical band gaps obtained via the DFT + D method are very close to the experimental values. The investigation of the imaginary part of the dielectric function shows the presence of four electronic transitions. The refractive index of the chalcofluorides is decreased with an increase in the energy bandgap (Eg). An intense absorption occurred along the [010] direction, which reached a value of about 2 × 105 cm−1. The highest energy loss is observed along the [010] direction for Ba2SnSe3F2, which has the highest number of total electrons. © 2023, The Tunisian Chemical Society and Springer Nature Switzerland AG.