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 ${\mathrm{GaN}}_x{\mathrm{As}}_{\text{1−x}}$ alloys with $\text{x<0.04.}$ 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.