Quasiparticle Energies and Band Gaps of Graphene Nanoribbons

TL;DR

This paper uses a first-principles GW approach to calculate quasiparticle energies and band gaps of graphene nanoribbons, revealing significant corrections that impact their potential for electronic applications.

Contribution

It provides the first-principles quasiparticle band gap calculations for GNRs, highlighting the importance of electron-electron interactions and confinement effects.

Findings

Quasiparticle band gaps range from 0.5 to 3.0 eV for various GNR widths.

Significant self-energy corrections compared to previous methods.

GNRs may be suitable for electronic devices under ambient conditions.

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-dimension 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.