Gas Sensing by SnO2 Thin Films Prepared by Large-area Pulsed Laser Deposition

We present resistive gas responses of tin oxide thin films prepared by large-area pulsed laser deposition. The influence of the oxygen background pressure during deposition on the sensor response to CO was investigated. Film properties such as resistance, morphology and gas sensing signal of samples deposited under different conditions were examined. Palladium was introduced by sputtering of thin layers and subsequent annealing to increase the stability and response to CO in humid background. The sensor's responses to 5-50 ppm CO and 0.5-1 ppm of NO2 were investigated at different operation temperatures and levels of relative humidity.