Tuning the electronic properties of graphene oxide nanoribbons with armchair edges through lithium doping

Abstract

The electronic properties of armchair graphene oxide nanoribbons (AGONRs) doped with lithium atoms at one-edge, centre and both-edges, in comparison with the H-terminated cases are investigated using the local density approximation based on density functional theory. The results indicate that H-terminated AGONRs are a direct band gap semiconductor with an energy gap of 0.225 eV involving hybridization and charge transfer among C-2p and O-2s, 2p electrons near the Fermi level in the conduction band. The AGONRs for centre Li-doping is an indirect band gap semiconductor with an energy gap of 0.164 eV involving hybridization among C-2p, Li-2s, 2p and O-2s, 2p electrons and electrical conductivity of lithium atoms. The one-edge and both-edge Li-doped AGONRs is metallic with contributions from Li-2p, O-2p and H-1s electrons. Their band gaps decrease when doping with oxygen and lithium atoms. In addition, charge density difference calculations show charge transfer from C and Li atoms to O atoms. Thus, doping atoms and different doping configurations can be used to tune the band gap of H-terminated AGONRs.