Crystal structure and electronic properties of wurtzite MgxZn1-xO: Ab initio study

Abstract

The current paper reports on the alloying effect on the structural and electronic properties of the hexagonal wurtzite MgxZn1-xO. The calculations are carried out using full-potential linearized augmented plane wave method. The Wu-Cohen and Tran-Blaha modified Becke-Johnson generalized gradient approximations are used to describe the exchange-correlation potential. Our results show generally reasonable accord with experiment. By alloying ZnO with different concentrations of Mg, the variation of the lattice parameters versus Mg content violates slightly the Vegard's law. The analyses of the band structure and density of states show that MgxZn1-xO (0 ≤ x ≤ 1) exhibits a semiconducting character with a direct band-gap (Г-Г). The variation of the latter versus alloy composition x is found to be non-linear showing a band-gap bowing parameter of −1.33 eV.