Nanotransport in polyacetylene single fiber: Toward the intrinsic properties

Abstract

The electrical transport properties of iodine doped polyacetylene (PA) nanofibers were measured as function of temperature in micron and sub-micron scale. Polyacetylenc fiber network measured in micron scale shows weaker temperature dependence of resistivity and smaller negative magnetoresistance (MR) at T=1.5K compared to those of hulk PA film. The reaction of Au electrodes with dopant became serious in submicron experiment, so that stripes of Pt electrodes with 100nm separation were patterned on top of the SiO 2 substrate to prevent the reaction. Non-ohmic I-V charactersitics are observed in PA nanofiber. The gate dependence shows the charge carrier to be hole with mobility μ FET ∼ 4.4×10 -5 cm 2 /Vs at 233K. The non-ohmic I-V dependence at high electric fields could be originated from the soliton tunneling conduction in PA nanofiber.