Authors: E. Brunet, G.C. Mutinati, S. Steinhauer, A. Koeck
Affilation: AIT Austrian Institute of Technology GmbH, Austria
Pages: 102 - 105
Keywords: gas sensor, SnO2 nanowires
A novel gas sensor device based on a network of tin dioxide (SnO2) nanowires is presented. The high surface-to-volume ratio presented by the network of ultralong nanowires enables increased gas sensing performances in comparison to single nanowire sensor. For the synthesis of the SnO2 nanowire network, a SnO2 thin film of ~300 nm was deposited by spray pyrolysis on a silicon wafer. Afterwards the Si wafers were cleaved, the two pieces glued together to leave a gap of ~200 µm and annealed side by side in Ar at ~950°C for 1 hour. Ultra-long SnO2 nanowires grow from one chip to the other so that an electrical contact is established between the two chips. This interconnected network of nanowires has shown a response of 92% to 1.4 ppm H2S at 300°C. In the presence of H2, the sensor response is proportional to the concentration of H2 up to 100 ppm. In synthetic air with 60% relative humidity, the sensor response reaches 52% for 60 ppm H2 at room temperature, which is remarkable to build a sensor device with low power consumption.