Characterization of ozone sensors based on WO3 reactively sputtered films:: influence O2 concentration in the sputtering gas and working temperature

We report on electrical responses of tungsten oxide thin film ozone sensors based on a tungsten trioxide (WO3)/tin oxide (SiO2)/Si structure with interdigitated Pt electrodes. The influence of O-2 concentration in the sputtering gas and working temperature of the sensor are investigated. Sensitivity to ozone increases with O-2 content in the sputtering gas. It reaches its highest value for sensors fabricated with 50% O-2. For these sensors, the best ozone sensitivity and shortest response and recovery times are obtained at a working temperature of 523 K. Ozone sensitivity is compared to other ozone sensors. (C) 2004 Elsevier B.V. All rights reserved.