Effect of thickness of platinum catalyst clusters on response of SnO2 thin film sensor for LPG

This paper reports the sensing response characteristics of rf-sputtered SnO2 thin films (90 nm thick) loaded with platinum catalyst cluster of varying thickness (2-20 nm) for LPG detection. The enhanced response (5 x 10(3)) was obtained for 200 ppm LPG with the presence of 10 nm thin and uniformly distributed Pt catalyst clusters on the surface of SnO2 thin film at a relatively low operating temperature (220 degrees C). The high response for LPG is shown to be primarily due to the enhanced catalytic activity for adsorbed oxygen on the surface of SnO2 thin film besides the spill over mechanism at elevated temperature. (C) 2010 Elsevier B.V. All rights reserved.