Effects of Mg doping on physical properties of zinc-blende mercury selenide HgSe compound

Structural, electronic and optical properties of Hg1-xMgxSe (x = 0, 0.25, 0.5, 0.75 and 1) alloys have been investigated by using density functional theory calculations (DFT) with the generalized gradient approximation under the Perdew-Burke-Ernzerhof (GGA-PBE) method. In fact, we have studied and discussed the structural, electronic and optical properties of the HgSe when substituting the Mercury Hg by Magnesium element (Mg). The calculated structural parameters show a decrease trend with increasing the concentration of doping by the Mg element. The obtained results for the electronic properties indicate that HgSe is a semimetal material. However, Hg1-xMgxSe (x = 0.25, 0.5, 0.75 and 1) are semiconductors. Also, such materials exhibit a direct bandgap at Gamma point symmetries. The optical parameters such as real and imaginary parts of dielectric function e(omega), the refractive index n(omega), the absorption coefficient alpha(omega), the reflectivity R(omega), the optical conductivity sigma(omega) and the energy loss function L(omega) were also studied and discussed.