UV light activation of tin oxide thin films for NO2 sensing at low temperatures

A novel approach to operate semiconductor gas sensor at low temperatures avoiding the poisoning of the surface is described. The effects of UV light illumination on the performance of SnO2 thin film gas sensors toward an oxidising gas of increasing interest due to environmental monitoring, like NO2 are reported. The thin films gas sensors were prepared according to the rheotaxial growth and thermal oxidation (RGTO) technique with de sputtering in Ar atmospheres. Results has shown that there is an enhancement of the performances with UV exposure: a decrease in the response and recovery time and no poisoning effect. This is promising for the development of a sensor for NO2 working at room temperature. (C) 2001 Elsevier Science B.V. All rights reserved.