Dresden 2011 – scientific programme
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O: Fachverband Oberflächenphysik
O 52: Nanostructures at surfaces: Wires, tubes
O 52.8: Talk
Wednesday, March 16, 2011, 16:45–17:00, WIL B122
Tin dioxide nanowire gas sensor for detection of the toxic gases CO, H2S and SO2 — •Elise Brunet1, Christian Griessler1, Giorgio Mutinati1, Stephan Steinhauer1, Anton Koeck1, Christian Edtmaier2, and Wolf-Dieter Schubert2 — 1AIT Austrian Institute of Technology GmbH, Health & Environment Department, Nano Systems, Vienna, Austria — 2Institute of Chemical Technologies and Analytics, Vienna University of Technology, Vienna, Austria
Metal oxide-based gas sensors rely on changes of electrical conductance due to interactions between the surrounding gas and the sensing layer. This sensing layer is most commonly a polycrystalline tin dioxide (SnO2) thin film. However, single crystalline SnO2 nanowires have higher chemical resistance and thermal stability and are therefore of great interest for highly sensitive gas detecting devices. We present nanosensors based on single crystalline SnO2 nanowires, which are very sensitive to the highly toxic gases CO, H2S and SO2. A SnO2 thin film is deposited by spray pyrolysis on a SiO2/Si substrate and further tempered 1h at 900°C in Ar-atmosphere resulting in the growth of single crystalline SnO2 nanowires. The sensing performance of the nanowire sensor is presented. Exposure to 260ppm CO leads to a sensitivity of 1.5% at 300°C. In presence of 1,5ppm H2S the highest sensitivity of 25% is obtained at 250°C and the sensor response to 27ppm SO2 reaches a sensitivity of 8% at 400°C. The specific responses achieved from the nanowire sensor at different temperatures are crucial for a selective detection of the toxic gases CO, H2S and SO2.