Electrochemical deposition of polypyrrole nanolayers on discontinuous ultrathin goldfilms

Abstract

Ultrathin layers of polypyrrole (PPy) were electrochemically grown between microelectrodes on aSi/SiO2 substrate. Conducting nanolayers of PPy are directly grown onto ultrathin discontinuousgold (Au) film between the microelectrodes, with thicknesses in the range 10–100 nm. Thesystem therefore forms a novel (PPy/Au) nanocomposite conductor. Atomic forcemicroscopy (AFM) imaging and conductivity measurements indicate that at allthicknesses a relatively uniform film is formed but with significant roughness thatreflects the roughness of the metallic island layer. In PPy/Au films with thickness∼10 nm, the small barriers around the gold islands dominate the conduction, and as the filmthickness increases to 100 nm the intrinsic conductivity of highly doped PPy dominates thecharge transport.