Conductance of polymer nanowires fabricated by a combined electrodeposition and mechanical break junction method

We electrochemically deposit conducting polymer to bridge two closely placed electrodes, and then form a polymer nanowire by stretching the polymer bridge with the electrodes. During stretching, the conductance increases initially as the polymer chains are aligned in parallel, and then decreases in a stepwise fashion, due to abrupt changes in the nanowire thickness. We study the current-voltage (I-V) characteristics of the nanowire as a function of its electrochemical potential in an analogous fashion to the control of the gate voltage in semiconductor devices. Depending on the potential, the I-V curves vary from ohmic to rectifying characteristics. (C) 2001 American Institute of Physics.