Design, Fabrication and Testing of a Novel Gas Sensor utilizing Vertically Aligned Zinc Oxide Nanowire Arrays

ABSTRACTWe report on a novel, non-destructive, in-situ approach toward connecting and electrically contacting vertically aligned zinc oxide nanowire arrays using conductive gold nanoparticles. A chemical gas-sensing device was constructed and tested using this nano-architecture. Well-aligned, single-crystalline zinc oxide nanowires were grown through a direct thermal evaporation process at 550 °C on gold catalyst layers. Electrical contact to the top of the NW array was established by creating a contiguous nanoparticle film through electrostatic attachment of conductive gold nanoparticles exclusively onto the tips of nanowires. The gas-sensing device fabricated through this approach was found to be sensitive to both reducing (methanol) and oxidizing (nitrous oxides) gases. This assembly approach is amenable to any array of one-dimensional nanostructures for which a top contact electrode is needed.