title: Quasiparticle energies and band gaps in graphene nanoribbons.
abstract: We present calculations of the quasiparticle energies and band gaps of graphene nanoribbons (GNRs) carried out using a first-principles many-electron Green's function approach within the GW approximation. Because of the quasi-one-dimensional nature of a GNR, electron-electron interaction effects due to the enhanced screened Coulomb interaction and confinement geometry greatly influence the quasiparticle band gap. Compared with previous tight-binding and density functional theory studies, our calculated quasiparticle band gaps show significant self-energy corrections for both armchair and zigzag GNRs, in the range of 0.5-3.0 eV for ribbons of width 2.4-0.4 nm. The quasiparticle band gaps found here suggest that use of GNRs for electronic device components in ambient conditions may be viable.
authors.affiliation: Department of Physics, University of California at Berkeley, California 94720, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.forename: Cheol-Hwan
authors.initials: CH
authors.lastname: Park
authors.forename: Young-Woo
authors.initials: YW
authors.lastname: Son
authors.forename: Marvin L
authors.initials: ML
authors.lastname: Cohen
authors.forename: Steven G
authors.initials: SG
authors.lastname: Louie