First-principles study of cubic AlxGa1−xN alloys

We present first-principles calculations of the structural and electronic properties of cubic AlxGa1−xN ordered alloys in the chalcopyrite and luzonite structures. We have investigated the lattice parameters and band gap energies. The lattice constant a exhibits a small downward bowing. The calculated band gap variation gives a small bowing in good agreement with the experimental reports. We notice a direct to indirect band gap crossover at x (Al) = 0.51.