High response and stability in CO and humidity measures using a single SnO2 nanowire

Single SnO2 metal oxide nanowires are used at the nanoscale level as individual monocrystal for the electrical transduction of the gas interaction with these sensing materials. Electrical contact characteristics and resistance variations under different gas ambient are analyzed from two- and four-probes measurements of individual nanowires. These data have allowed the estimation of their resistivities and contact resistances. At the gas sensor working conditions, AC impedance spectroscopy technique has extensively been applied to analyze the interaction with the gas molecules and study the influence of the nanowire diameter size on the electrical transduction processes. CO and humidity behaviors are reported for single SnO2 nanowires with CO detection threshold smaller than 5 ppm and measurement instability lower than 4%. (c) 2006 Elsevier B.V. All rights reserved.