title: Negative differential resistance in oxidized zigzag graphene nanoribbons.
abstract: A theoretical study of zigzag graphene nanoribbons (ZGNRs) with an epoxy-pair chain (ZGO) is performed. The electronic transport properties are mainly evaluated by non-equilibrium Green's functions using the TRANSIESTA package. The results indicate that the graphene oxide can have a negative differential resistance (NDR) phenomenon, supported by bias-dependent transmission curves of different spin orientations. Applying non-zero bias voltages makes the density of states (DOS) of the right electrodes shift down. Due to an energy gap between the LUMO and LUMO+1 in ZGOs, with a certain bias, the conduction band of the right electrode cannot match the LUMO of the scattering region, then NDR occurs. With a larger bias, NDR ends when the second conduction band of the right electrode's DOS covers the LUMO of the scattering region. Since most of proposed ZGO systems possess such a gap between the LUMO and LUMO+1, NDR can be widely observed and this discovery may provide great potential applications in NDR-based nanoelectronics by using modified graphene materials.
authors.affiliation: Center for Advanced Bionanosystems and School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457, Singapore.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.forename: Chang Ming
authors.initials: CM
authors.lastname: Li
mesh_terms: D017097:Electric Impedance; D004852:Epoxy Compounds / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010084:Oxidation-Reduction
chemical_list: D004852:Epoxy Compounds; D037742:Nanotubes, Carbon; D006108:Graphite