Departmental Papers (ESE)


Although carbon nanofibers might have wide potentials in applications, most of their physical properties have yet to be investigated. This paper reports on the low-temperature electronic transport properties of an electrospun polyacrylonitrile-based carbon nanofiber, with its mean diameters around 120 nm. The resistance of the carbon fiber was measured using the four-point probe method from 295 down to 15 K. The semiconducting nature of the fiber is revealed by its positive temperature coefficient of conductance, i.e., an increase in conductivity with the temperature. The conductivity (σ) depends on temperature according to the relation, σ = 5768T 0.338exp(-2 x 10-6 eV/kT), suggesting an almost zero bandgap and a strong temperature dependence of carriers mobility. Such temperature dependence of conductivity is very similar to that found in carbon microfibers, and can be explained using a simple two-band model with temperature-dependent mobility.

Document Type

Journal Article

Date of this Version

June 2004


Copyright 2004 IEEE. Reprinted from IEEE Transactions on Nanotechnology, Volume 3, Issue 2, June 2004, pages 221-224.
Publisher URL:

This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the University of Pennsylvania's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to By choosing to view this document, you agree to all provisions of the copyright laws protecting it.


Carbon nanofiber, electrospinning, hopping, low-temperature electronic properties, simple two-band model (STB)



Date Posted: 09 November 2004

This document has been peer reviewed.