Novel fabrication of an SnO2 nanowire gas sensor with high sensitivity

摘要

We fabricated a nanowire-based gas sensor using a simple method of growing SnO2 nanowires bridging the gap between two pre-patterned Au catalysts, in which the electrical contacts to the nanowires are self-assembled during the synthesis of the nanowires. The gas sensing capability of this network-structured gas sensor was demonstrated using a diluted NO2. The sensitivity, as a function of temperature, was highest at 200 degrees C and was determined to be 18 and 180 when the NO2 concentration was 0.5 and 5 ppm, respectively. Our sensor showed higher sensitivity compared to different types of sensors including SnO2 powder-based thin films, SnO2 coating on carbon nanotubes or single/multiple SnO2 nanobelts. The enhanced sensitivity was attributed to the additional modulation of the sensor resistance due to the potential barrier at nanowireanowire junctions as well as the surface depletion region of each nanowire.