First-principles study of the structural, electronic and optical properties of the cubic triangular quaternary ZnxCdyHg1-x-yTe alloys under hydrostatic pressure

Abstract

In the present computational study, we have explored the structural, electronic and optical properties of ZnTe, CdTe and HgTe binary compounds and their ternary alloys ZnxCd1-xTe, ZnxHg1-xTe and CdxHg1-xTe as well as their ordered quaternary ZnxCdyHg1-x-yTe alloys using the full potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory. We have numerically estimated the total energies, the lattice parameters, the bulk moduli and their first pressure derivative using the generalized gradient approximation (GGA). The band structure is computed using the modified Becke-Johnson (TB-mBJ) approximation. Results of our study show a nonlinear dependence of the composition on the lattice constant, bulk modulus and band gap for the binary and ternary compounds as well as for the quaternary alloys. Additionally, the dielectric function, the refractive index and the loss energy were also reported. The pressure effect on the band gap energy and optical properties were also investigated and reported. Our results are in good agreement with experimental values and theoretical data available in the literature.