A DFT study of the structural, optoelectronic, elastic, and thermodynamic properties of the tetragonal monochalcogenide InTe

In this research paper, the application of density functional theory by the full-potential linearized augmented plane wave method integrated with the Wien2k code has enabled us to determine structural, optoelectronic, elastic and thermodynamic properties. Analysis of the optoelectronic properties reveals that the tetragonal phase of the InTe binary compound is a semiconductor, with an electronic band gap of 0.0296 eV calculated by the GGA-mBJ approximation. This value is measured between the valence band maximum located at the M point and the conduction band minimum located between the X and P points. The IRelast package, integrated into the Wien2k software, is used to determine elastic properties, showing that the interatomic bonds in the binary compound InTe are predominantly ionic, with a low contribution from covalent bonds. Concerning the study of thermodynamic properties, we use the Gibbs2 code and the quasi-harmonic Debye model. We examined the influence of pressure and temperature on various thermodynamic variables such as the volume (V), the bulk modulus (B), the thermal expansion coefficient (α), the Debye temperature (θ_D), the heat capacity at constant pressure (C_P), the heat capacity at constant volume (C_V), the Gibbs free energy (G), and the entropy (S).