Combined effects of defects and hydroxyl groups on the electronic transport properties of reduced graphene oxide

The effects of four typical defects on the hydroxyl groups' migration and the conductivity of graphene have been studied using density functional theory and nonequilibrium Green's function formalism. An obvi- ous anisotropy of the diffusion barriers along different paths is correlated to the symmetric behavior of spin- polarized charge density around the defects. The migration energy scenario indicates that the defects effectively hinder the hydroxyl groups' migration toward them, indicating that most hydroxyl groups could be stabilized outside the defect region in reduced graphene oxide. Through the electronic transport calculations and local density of states analysis, hydroxyl groups locating outside of the defect region will cause the transport channels near the Fermi level to disappear and reduce the conductance considerably.