Self-assembled rigid conjugated polymer nanojunction and its nonlinear current-voltage characteristics at room temperature

A gold/polymer/gold nanojunction was fabricated by the self-assembly of a rigid polymer, namely poly(p-phenyleneethynylene)s with thioacetyl groups, between gold nanogap electrodes. The self-assembly depends on: (i) the ideal rigidity of the polymer molecules and (ii) the strong affinity of the thioacetyl/thiol end groups of the polymer for the Au surface. The current-voltage (I-V) characteristics of the conjugated polymer nanojunction exhibited stepwise features (some steps appeared as peaks) at room temperature. The I-V can be explained as electron tunneling through the nanojunction. (C) 2004 American Institute of Physics.