Response behaviour of tin oxide thin film gas sensors grown by MOCVD

Tin oxide is the most widely studied semiconducting oxide for use in gas sensor applications. However, the majority of previous study has been centred around porous media produced as thick films or thin sputtered films. This paper concerns the behaviour of relatively non-porous thin films grown by metal-organic chemical vapour deposition (MOCVD) and presents their response behaviour to the hazardous gases H2S, CH4 and NO2. The films were produced from tetratertiarybutoxytin at 350 degrees C. They were found to act as selective H2S sensors at room temperature and show sensitive responses to all three gases above 200 degrees C. The response to all gases is a reduction in resistance and the effect of water vapour on the response is small. (C) 2000 Elsevier Science S.A. All rights reserved.