The aging effect on SnO2-Au thin film sensors: electrical and structural characterization

There is an increasing demand for semiconducting gas sensors for several mo nitoring applications that have sensitivity, selectivity and reliability on a long-term scale. In this paper, we have described the preparation of SnO 2-Au thin film sensors by the RGTO technique; these sensors have proved to be capable of sensitive and selective detection of CO. The TEM and AES anal ysis showed that 6 months of sensor aging at 400 degrees C did not produce any valuable rearrangement of gold atoms onto a tin dioxide surface, Most o f the sensor resistance variation was observed during the first 20 days, an d a limited drift was observed in the remaining period. (C) 2000 Elsevier S cience S.A. All rights reserved.