The temperature dependence of electron transport in a composite film of graphene oxide with single-wall carbon nanotubes: an analysis and comparison with a nanotube film

Abstract

The work describes the results of low-temperature studies (5–291 K) of electron transport in composite films of graphene oxide with single-wall nanotubes (GO-SWNTs) obtained by vacuum filtration of their aqueous suspension. The emergence of conductivity in such films is shown to be related to nanotubes, since the GO film, unlike the nanotube film, has no conductivity. For a comparative analysis, the electrical conductivity of the SWNT film was also considered. The GO-SWNT and SWNT films exhibit a semiconductor behavior with a negative temperature coefficient of electrical conductivity. The temperature dependences of film resistance have been analyzed using the 3D Mott model that describes the motion of electrons (due to thermally activated tunneling through barriers) with variable-range hopping (the VRH model) in an interval of 5–240 K. The analysis of the dependences yielded estimates for the parameters of electron transport in the composite GO-SWNT film and SWNT nanotube film: the average hopping range and energy of the electron; their temperature dependences have been plotted. A comparison of these parameters for different films showed that nanotube contact with the GO surface hinders electron transport in the composite film. To describe the temperature dependence of film resistance at Т > 240 K, the Arrhenius model is used from which the potential barrier value has been obtained.