Structural, chemical bonding and optoelectronic properties of Mg doped zinc chalcogenides: A first principles study

A first-principal technique is employed to investigate the concentration dependence of the structural, electronic band structure, optical and chemical bonding properties of Zn1−xMgxS, Zn1−xMgxSe and Zn1−xMgxTe alloys. Structural parameters such as lattice constants and bulk moduli are found to vary non-linearly with changing concentration x and deviating from Vegard׳s law. Parent binaries as well as ternary alloys have a direct band gap (Γ–Γ) which increases non-linearly with increment in concentration. Chemical bonding nature changes from strong covalency to partial ionic character in increasing Mg-contents. The direct band gap and high optical activity in visible and ultraviolet range reveal the implication of these alloys in the optoelectronic devices applications.