Band structures of wurtzite InN and Ga1-xInxN by all-electron GW calculation

The experimentally reported bandgap of wurtzite-type InN dramatically decreased from 1.9 eV to 0.7-0.8 eV very recently. In this paper we report first-principles electronic band-structure calculations of InN by using the all-electron full-potential linearized augmented-plane-wave (FLAPW) method in both local-density approximation (LDA) and GW approximation (GWA), and provide the reliable theoretical bandgap of InN. Our calculation suggests that InN is a narrow-gap semiconductor and strongly supports the recently reported smaller bandgaps. Moreover, we reproduce the bandgap change of Ga1-xInxN ternary alloys as a function of In content x. The present work supports the possibility of bandgap control in the entire range of visible light, using nitrides alone.