Photosensitivity activation of SnO2 thin film gas sensors at room temperature

In this work the results of photoconductivity measurements on SnO2 thin films gas sensors grown by the rheotaxial growth and thermal oxidation (RGTO) technique are presented. It is shown that thin films, illuminated with UV light at room temperature, become sensitive to oxygen and reducing gases like CO. On the contrary the response to CO is not affected by illumination when the sensor is kept at the usual working temperature (T = 673 K).