VRH transport in fluorinated mono-layer graphene. Resistivity of fluorinated mono-layer graphene in the charge neutrality region plotted as a function of T-1 (a) and T-1/3 (b). (c) The values of the hopping parameter T0 as a function of carrier density for the samples where transport occurs by two-dimensional Mott VRH. (d) Schematic diagrams of the energy dispersion of fluorinated mono-layer graphene (left panel) and of the energy dependence of the density of electron states, with the Fermi level at zero energy (right panel). The localised states are shown by the shaded area. (e) Resistivity of fluorinated mono-layer graphene (exfoliated from CF0.28 graphite) in the charge neutrality region plotted as a function of T-x. The solid lines represent fits to the experimental data where x = 1 for thermally activated transport, x = 1/2 for Efros-Shklovskii VRH and x = 1/3 for 2D Mott VRH. The best t is obtained for x = 1/2.
Withers et al. Nanoscale Research Letters 2011 6:526 doi:10.1186/1556-276X-6-526