Kenji Murao

Anomalous voltage‐controlled negative resistance in Pt‐insulator‐conductive polymer‐Au junctions

Anomalous electrical properties have been found for platinum‐insulator‐polypyrrole‐gold junction cells where the insulator layer is doped with a small amount of polypyrrole. The electroformed samples exhibit voltage‐controlled negative resistance (VCNR) with an exceptionally low peak voltage of 1.75 V. Linear sweeps of dc voltages between 0 and 3 V result in a switching phenomenon in which a low resistance on state (VCNR state) and a high resistance off state alternately appear. These anomalies are tentatively assumed as being due to reversible charge storage at the polypyrrole sites in the insulator layer.

Preparation and electrochemistry of a new bilayer electrode, Pt/poly[RuII(4-vinyl-4′-methyl-2,2′-bipyridine)32+·2(ClO4–)]/polypyrrole

Mediated redox reactions of a polypyrrole film were observed at a new bilayer electrode, the title system, which was prepared by the anodic oxidation of pyrrole in acetonitrile at a Pt electrode modified with the Ru complex followed by repeated potential scans (–2.10 to + 1.15 V vs. Ag/Ag+ reference electrode).