title: All-electron GW quasiparticle band structures of group 14 nitride compounds.
abstract: We have investigated the group 14 nitrides (M3N4) in the spinel phase (γ-M3N4 with M = C, Si, Ge, and Sn) and β phase (β-M3N4 with M = Si, Ge, and Sn) using density functional theory with the local density approximation and the GW approximation. The Kohn-Sham energies of these systems have been first calculated within the framework of full-potential linearized augmented plane waves (LAPW) and then corrected using single-shot G0W0 calculations, which we have implemented in the modified version of the Elk full-potential LAPW code. Direct band gaps at the Γ point have been found for spinel-type nitrides γ-M3N4 with M = Si, Ge, and Sn. The corresponding GW-corrected band gaps agree with experiment. We have also found that the GW calculations with and without the plasmon-pole approximation give very similar results, even when the system contains semi-core d electrons. These spinel-type nitrides are novel materials for potential optoelectronic applications because of their direct and tunable band gaps.
authors.affiliation: Department of Physics and Quantum Theory Project, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: Iek-Heng
authors.initials: IH
authors.lastname: Chu
authors.affiliation: Institute for Theoretical Physics, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Anton
authors.initials: A
authors.lastname: Kozhevnikov
authors.affiliation: Institute for Theoretical Physics, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Schulthess
authors.affiliation: Department of Physics and Quantum Theory Project, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: Hai-Ping
authors.initials: HP
authors.lastname: Cheng