Fabrication and electrical characterization of polyaniline-based nanofibers with diameter below 30 nm

We fabricate and electrically characterize electrospun nanofibers of doped polyaniline/polyethylene oxide (PAn/PEO) blend with sub-30 nm diameter. Fiber diameters near 5 nm are obtained for optimized process parameters. Scanning conductance microscopy (SCM) shows that fibers with diameter below 15 nm are electrically insulating; the small diameter may allow complete dedoping in air or be smaller than phase-separated grains of PAn and PEO. Electrical contacts to nanofibers are made by shadow mask evaporation with no chemical or thermal damage to the fibers. Single fiber I–V characteristics show that thin fibers conduct more poorly than thick ones, in agreement with SCM data. I–Vs of asymmetric fibers are rectifying, consistent with formation of Schottky barriers at the nanofiber-metal contacts.