Nanotransport in polyacetylene single fiber: Toward the intrinsic properties

The electrical transport properties of iodine doped polyacetylene (PA) nanofibers were measured as function of temperature in micron and sub-micron scale. Polyacetylene 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 bulk PA film. The reaction of all electrodes with dopant became serious in submicron experiment, so that stripes of Pt electrodes with 100nm separation were patterned on the top at the SiO₂ substrate to prevent the reaction. Non-ohmic I-V characteristics are observed in PA nanofiber. The gate dependence shows the charge carrier to be hole with mobility μ_FET ∼ 4.4 × 10^-5 cm²/Vs at 233K. The non-ohmic I-V dependence at high electric fields could be originated fron the soliton tunneling conduction in PA nanofiber.