The Role of the Oxygen Impurity on the Electronic Properties of Monolayer Graphene: A Density-Functional Study

Oxidation during the fabrication of a two-dimensional carbon-based system (graphene) can not be avoided so that will affect the electronic properties of the system. In this study, we investigate the effect of the oxygen impurity on the electronic properties of monolayer graphene using density functional theory calculations. The calculations were performed using the (3 x 3) supercell model and were validated by the (1 x 1) supercell calculations. We find that by increasing the oxygen concentration from 6%, 11%, 17%, 33% and 50%, the band gap enhanced from 0.1 to 2.48 eV. An analysis using the partial density-of-states projected to the atoms confirmed that strong hybridizations between 0 - P-y AND C - P-z orbitals are responsible for inducing the enhancement of the bandgap. Therefore, we conclude that oxygen atoms are highly sensitive to changes in the electronic properties of monolayer graphene.