▎ 摘　　要

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 degrees C and further annealed in Ar/H(2) at 900 degrees C; monolayer ribbons were selected for the fabrication of electronic devices. GNR devices on Si/SiO(2) substrates exhibit an ambipolar electric field effect typical for graphene. The conductivity of monolayer GNRs (similar to 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 H(2)SO(4)/KMnO(4) 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. (C) 2009 American Institute of Physics. [doi:10.1063/1.3276912]