Effect of nitrogen concentration on electronic energy bands of Ga1-xInxNyAs1-y alloys

Using the pseudopotential scheme under the virtual crystal approximation, t he effect of nitrogen content on electronic energy bands of Ga1-xInxNyAs1-y alloys lattice matched to GaAs in the zinc-blend structure has been invest igated. 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 a re direct-gap semiconductors for all nitrogen fractions y (0 less than or e qual toy less than or equal to0.35). Moreover, these band gaps exhibit larg e 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 Vec hten model. (C) 2000 Elsevier Science B.V. All rights reserved.