STUDY OF ELECTRICAL CONDUCTIVITY OF THERMALLY REDUCED GRAPHENE OXIDE

Abstract

Graphene oxide under study was obtained by a modified Hummers method.Samples were subjected to thermal reduction in a temperature range from 200° to 300°C in an atmosphere of argon and in vacuum.Results of measurements of volt-ampere characteristics of the samples in a temperature range from 80 to 300 K showed the presence of linear dependence of logarithm of current on a reciprocal temperature above 160-180 K.At temperatures below these values a power dependence of current on the temperature is observed.In this paper an assumption is made that both a Mott variable-range hopping (VRH) and the Efros-Shklovskii (ES-) VRH mechanism affect the electrical conductivity of graphene oxide in the range from 10 to 180 K.A contribution of each mechanism depends on conditions of carrying out the thermal reduction.