Conductivity measurements of PEDOT nanowires on nanoelectrodes

We have prepared very thin, conducting polymer nanowires of poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) with diameters under 5nm on a thermally grown SiO2/Si substrate by a molecular combing method. We have measured the conductivity of the nanowires using nanoelectrodes. Ohmic behavior of the PEDOT nanowires was obtained when applied voltages were smaller than 100 mV. The conductance of the nanowires decreased with decreasing temperature and the temperature dependence of the conductance was explained by the quasi one-dimensional variable range hopping (VRH) model. After all the nanowires placed on the gap of the nanoelectrodes were cut, the current was drastically decreased, down to the background level. We have thus provided direct evidence that the PEDOT nanowires were responsible for conduction between the nanoelectrodes.