Charge transport in transparent single-wall carbon nanotube networks

Abstract

We report the electric-field effects and magnetotransport in transparent networks ofsingle-wall carbon nanotubes (SWNT). The temperature dependence of conductance of thenetwork indicates a 2D Mott variable-range hopping (VRH) transport mechanism. Electricfield and temperature are shown to have similar effects on the carrier hops and identicalexponents for the conductance of the network are obtained from the high electric field andtemperature dependences. A power-law temperature dependence with an exponent3/2 for the threshold field is obtained and explained as a result of the competing contributionsfrom electric field and phonons to the carrier hop. A negative magnetoresistance(MR) is observed at low temperatures, which arises from a forward interferencescattering mechanism in the weak scattering limit, consistent with the VRH transport.