Frequency- and electric-field-dependent conductivity of single-walled carbon nanotube networks of varying density

Abstract

We present measurements of the frequency and electric field dependent conductivity of single walled carbon nanotube(SWCNT) networks of various densities. The ac conductivity as a function of frequency is consistent with the extended pair approximation model and increases with frequency above an onset frequency ${\omega }_0$ which varies over seven decades with a range of film thickness from sub-monolayer to 200 nm. The nonlinear electric field-dependent DC conductivity shows strong dependence on film thickness as well. Measurement of the electric field dependence of the resistance R(E) allows for the determination of a length scale $L_E$ possibly characterizing the distance between tube contacts, which is found to systematically decrease with increasing film thickness. The onset frequency ${\omega }_0$ of ac conductivity and the length scale $L_E$ of SWCNT networks are found to be correlated, and a physically reasonable empirical formula relating them has been proposed. Such studies will help the understanding of transport properties and benefit the applications of this material system.

arXiv comment7 pages and 6 figures

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• An RF Circuit Model for Carbon Nanotubes
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• Determination of the magnetization scaling exponent for single crystal La${}_{0.8}$Sr${}_{0.2}$MnO${}_3$ by broadband microwave surface impedance measurements

Cited by in corpus (1)

• Effects of Diffusion on Photocurrent Generation in Single-Walled Carbon Nanotube Films