Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 7: "New" Materials and New Physics in "Old" Materials I

HL 7.4: Vortrag

Montag, 26. März 2012, 10:15–10:30, EW 015

Network of SnO2 nanowires for gas sensing application — •Elise Brunet, Giorgio Cataldo Mutinati, Stephan Steinhauer, and Anton koeck — Health & Environment Department, Molecular Diagnostics, AIT Austrian Institute of Technology GmbH, 1220 Vienna, Austria

SnO2 is an n-type semiconductor particularly used in metal oxide gas sensors, whose principle relies on changes of electrical conductance due to interactions between the surrounding gas and the sensing layer. We present a gas sensor device, whose sensing layer is reduced to a bundle of SnO2 nanowires. The surface to volume ratio is increased, which enlarges the number of interactions between the gas molecules and the SnO2 surface and improves the sensitivity of the sensor device.

A SnO2 thin film is deposited by spray pyrolysis on SiO2/Si substrates coated with CuO. The SnO2 film is then cleaved in two pieces, which are glued together on a support plate with a distance of about 150 micrometers. A thermal treatment of this assembly at 900°C in Ar-atmosphere results in the growth of single crystalline SnO2 nanowires on each of the two SnO2-coated substrates. The nanowires grown on the edges are long enough to interconnect and bridge the gap between the two substrates. The sensing performance of this network of SnO2 nanowires is investigated in the presence of small concentrations of CO, CO2, H2 and H2S in the low ppm range and compared with those of a single nanowire sensor device.