Theoretical study of the AlxGa1−xN alloys

In this work we use a first-principles method based on the density functional theory, the full-potential linear augmented plane-wave method (FPLAPW), in order to calculate the electronic structures of the AlxGa1−xN alloys in the cubic modification. We adopt a model which allows the simulation of the composition x=0.0, 0.25, 0.50, 0.75 and 1.0. We obtain the equilibrium lattice parameters, the bulk moduli, the formation energies, the miscibility curves and the effective masses of the conduction and valence bands in the [100], [111] and [110] directions. The results can be used in the parameterization of theories based on effective hamiltonians. To our knowledge, this is the first time such a systematic ab initio study of effective masses of these semiconductor alloys is accomplished.