Theoretical investigations of the structural, electronic and optical properties of Hg1-xCdxS alloys

摘要

The structural, electronic and optical properties of mercury cadmium sulfide (Hg1-xCdxS) alloys with x = 0.0, 0.25, 0.5, 0.75 are studied using density functional theory (DFT) within full-potential linearized augmented plane wave (FPLAPW) method. We used the local density approximation (LDA), the generalized gradient approximation (GGA), Hubbard-corrected functionals (GGA/LDA+U) and the modified Becke-Johnson (LDA/GGA)-mjb hybrid potentials to treat the exchange-correlation functional (E-ex). We found that LDA functional predicts better lattice constants than GGA functional. Mercury sulfide (HgS) binary alloy was found to exhibit a semi-metallic behavior using all functional with an inverted band gap close to the experimental value. However, the hybrid functionals were more successful than LDA and GGA functionals to predict the correct electronic structure of Hg1-xCdxS ternary alloys. The results of the electronic and optical band gaps are consistent for Hg1-xCdxS ternary alloys.