Ab initio study of structural parameters and gap bowing in zinc-blende AlxGa1−xN and AlxIn1−xN alloys

We present first-principles calculations of the structural and electronic properties of zinc-blende AlxGa1−xN and AlxIn1−xN 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 AlxGa1−xN, while for AlxIn1−xN 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 AlxIn1−xN.