Theoretical calculations of the properties of the binary compound semiconductor GaSb

Pseudopotentials and density functional theory (DFT) implemented in the ABINIT code were used to study the properties of the GaSb cubic alloy zinc-blende structure. Both the local density approximation and the generalized gradient approximation were used for the exchange-correlation (XC) potential calculation. The calculated lattice parameter aligns well with available experimental and theoretical results. Elastic constants, Young’s modulus, shear modulus, and anisotropy factor were determined, and the pressure dependence of elastic constants was investigated. Band gaps were initially calculated but showed discrepancies with experimental values due to the known band gap problem of DFT. To enhance accuracy, the Green function and screened Coulomb interaction approximation were introduced. The impact of thermal effects on compound properties was investigated using the quasi-harmonic Debye model, presenting variations in volume, heat capacities, thermal expansion coefficient, and Debye temperature concerning pressure and temperature.