Ab initio study of structural parameters and gap bowing in zinc-blende Al_xGa_(1-x)N and Al_xIn_(1-x)N alloys

摘要

We present first-principles calculations of the structural and electronic properties of zinc-blende Al_xGa_(1-x)N and Al_xIn_(1-x)N alloys by application of the all-electron full-potential linearized augmented plane-wave method within density-functional theory and the local-density approximation. When the parameter x varies, both the lattice constant a and the bulk modulus B are found to vary linearly for Al_xGa_(1-x)N, while for Al_xIn_(1-x)N the lattice parameters show an upward bowing. The calculated band-gap variation for the two alloys varies nonlinearly as a function of composition x, with a strong downward bowing for Al_xIn_(1-x)N.