Theoretical study of the band-gap anomaly of InN

Using a band-structure method that includes the correction to the band-gap error in the local-density approximation (LDA), we find that the band gap for InN is 0.8+/-0.1 eV, in good agreement with recent experimental data, but is much smaller than previous experimental value of similar to1.9 eV. The unusually small band gap for InN is explained in terms of the high electronegativity of nitrogen and, consequently, the small band-gap deformation potential of InN. The possible origin of the measured large band gaps is discussed in terms of the nonparabolicity of the bands, the Moss-Burstein shift, and the effect of oxygen. Based on the error analysis of our LDA-corrected calculations we have compiled the band-structure parameters for wurtzite AlN, GaN, and InN. (C) 2005 American Institute of Physics.