Study on ZnO-doped tin oxide thick film gas sensors

The effect of ZnO doping in SnO2 was investigated for gas sensor applications. Zinc oxide in different concentration, 2 wt% and 5 wt% was added to tin oxide powder prepared by a co-precipitation method. The gas sensor was made on alumina substrate by the screen-printing technique. The sensitivity for different gases such as methane, LPG, ethanol and CO gases was investigated at different temperatures and concentrations. Highest LPG gas sensitivity was observed for 2% Pd addition to 5% Zn-doped SnO2 gas sensor, with a negligible variation in resistance for ethanol.