We report on the structural and electrical properties of graphene nanoribbons (GNRs) produced by the oxidative unzipping of carbon nanotubes. GNRs were reduced by hydrazine at 95 °C and further annealed in Ar/ H 2 at 900 °C; monolayer ribbons were selected for the fabrication of electronic devices. GNR devices on Si/ SiO2 substrates exhibit an ambipolar electric field effect typical for graphene. The conductivity of monolayer GNRs (∼35 S/cm) and mobility of charge carriers (0.5-3 cm 2 /V s) are less than the conductivity and mobility of pristine graphene, which could be explained by oxidative damage caused by the harsh H2 SO4 / KMnO4 used to make GNRs. The resistance of GNR devices increases by about three orders of magnitude upon cooling from 300 to 20 K. The resistance/temperature data is consistent with the variable range hopping mechanism, which, along with the microscopy data, suggests that the GNRs have a nonuniform structure.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)