Role of nitrogen in the reduced temperature dependence of band-gap energy in GaNAs

We have observed a significant reduction in the temperature dependence of the absorption-edge energy in GaNxAs1-x alloys with x <0.04. The effect has been analyzed in terms of the recently introduced band anticrossing model that considers a coupling of the temperature-independent localized states of substitutional nitrogen atoms and the temperature-dependent extended states of GaAs. The model explains very well the alloy composition and the temperature dependence of the absorption-edge energy. We also compare the parameters that determine the temperature dependence of the band-gap energies in GaNAs and GaInNAs alloys. (C) 2000 American Institute of Physics. [S0003-6951(00)00545-3].