First-principles investigations of structural, electronic, optical and thermodynamic properties of CdxMg1−xS alloys

Abstract The structural, electronic, optical and thermodynamic properties of Cd x Mg 1− x S (0 ⩽  x  ⩽ 1) alloys in rock-salt phase have been investigated using first-principles method based on density functional theory. Our calculated lattice constants and bulk moduli for MgS and CdS are in good agreement with the available theoretical and experimental data. The lattice constants increase while the bulk modulus decreases with Cd concentration increasing. The calculated band structure shows that all considered compounds are indirect gap semiconductors. The density of states and optical constants such as complex dielectric function, extinction coefficient, refractive index and absorption coefficient are also calculated and analyzed in detail. Moreover, the thermodynamic stability of these alloys is investigated by the calculated T – x phase diagram.