A universal approach to electrically connecting nanowire arrays using nanoparticles—applicationto a novel gas sensor architecture

Abstract

We report on a novel, in situ approach toward connecting and electricallycontacting vertically aligned nanowire arrays using conductive nanoparticles.The utility of the approach is demonstrated by development of a gas sensingdevice employing this nano-architecture. Well-aligned, single-crystalline zincoxide nanowires were grown through a direct thermal evaporation process at550 °C on gold catalyst layers. Electrical contact to the top of the nanowire array was establishedby creating a contiguous nanoparticle film through electrostatic attachment of conductivegold nanoparticles exclusively onto the tips of nanowires. A gas sensing device wasconstructed using such an arrangement and the nanowire assembly was found to besensitive to both reducing (methanol) and oxidizing (nitrous oxides) gases. This assemblyapproach is amenable to any nanowire array for which a top contact electrode is needed.