Résumé: Using the pseudopotential scheme under the virtual crystal approximation, the effect of nitrogen content on electronic energy bands of Ga1:xInxNyAs1:y alloys lattice matched to GaAs in the zinc:blend structure has been investigated. In agreement with recent experiments, we find that the presence of nitrogen in the alloy of interest reduces the fundamental band gap energy. The behaviour of the important energy band gaps indicates that the alloys are direct:gap semiconductors for all nitrogen fractions y (0y<=0.35). Moreover, these band gaps exhibit large bowing parameters for the [Gamma]-[Gamma] and [Gamma]-X transitions. The large value of the bowing parameter of the [Gamma]-[Gamma]-transition is consistent with the experimental results and agrees with the prediction of the Van Vechten model.

Langue: Anglais