Inelastic electron transport in polymer nanofibers

Abstract

In this paper we present theoretical analysis of the electron transport in conducting polymers. We concentrate on the study of the effects of temperature on characteristics of the transport. We treat a conducting polymers in a metal state as a network of metallic-like grains connected by electron quantum tunneling via intermediate state localized on a polymer chain between the grains. To analyze the effects of temperature on this kind of electron intergrain transport we represent the thermal environment as a phonon bath coupled to the intermediate state. The electron transmission is computed using the Buttiker model within the scattering matrix formalism. This approach is further developed, and the dephasing parameter is expessed in terms of relevant energies including the thermal energy. It is shown that temperature dependencies of both current and conductance associated with the above transport mechanism differ from those typical for other conduction mechanisms in conducting polymers. This could be useful to separate out the contribution from the intergrain electron tunneling to the net electric current in transport experiments on various polymer nanofibers. The proposed model could be used to analyze inelastic electron transport through molecular junctions.