Transport and vibrational properties of poly(3,4-ethylenedioxythiophene) nanofibers

Nanofibers of poly(3,4-ethylenedioxythiophene) (PEDOT) have been electrochemically synthesized by the template method and their morphology determined using electron microscopy. A comparative resonant Raman scattering study has been performed on films, bundles of fibers and individual fibers of different diameters. Their temperature dependent transport properties have also been investigated and compared with the case of a PEDOT thin film. The PEDOT is found to be in an insulating state close to the metal-insulator transition. The temperature dependence of the fibers' conductance is larger than for the films, and this variation increases for a smaller fiber diameter. These results suggest that a confining effect on the PEDOT structure occurs during the electrochemical synthesis in the template. (C) 2002 Elsevier Science B.V. All rights reserved.