Gas sensing properties of interconnected ZnO nanowires

In this report, the structural, morphological, and gas-sensing properties of nanostructured thin films made of interconnected zinc oxide (ZnO) nanowires were studied. This paper is the first demonstration of functional devices based on such nanowires. Interconnected nanowires were grown via a two-stage process using, spray pyrolysis for the deposition of a ZnO seed layer on glass substrates, followed by a hydrothermal method for the growth of interconnected ZnO nanowires. Samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. Characterization of the films revealed that they were populated with interconnected ZnO nanowires, approximately ~20-30 nm in width with a hexagonal wurtzite structure after heat treatment. Samples were evaluated for NO2 gas sensing applications, and exhibited a considerable change in surface conductivity when exposed to N O2 at 200 °C. The influence of temperature between 65-260 °C on N O2 response of the developed sensors will be presented and discussed.