P1.2.4 Efficient detection of ammonia using SAW devices coated with oxide sensing layers

Event
14th International Meeting on Chemical Sensors - IMCS 2012
2012-05-20 - 2012-05-23
Nürnberg/Nuremberg, Germany
Chapter
P1.2 Resonant Sensors
Author(s)
V. Bhasker Raj, V. Gupta - Department of Physics and Astrophysics, University of Delhi (India), A. Nimal, M. Sharma - SAW division, Solid State Physics Laboratory (India), M. Tomar - Department of Physics, Miranda house, University of Delhi (India)
Pages
896 - 899
DOI
10.5162/IMCS2012/P1.2.4
ISBN
978-3-9813484-2-2
Price
free

Abstract

Ammonia sensing response characteristics of the Surface Acoustic Wave (SAW) sensors having different oxide thin films (ZnO, TeO2, SnO2 and TiO2) deposited by RF sputtering technique under the optimized parameters as sensing layer have been studied. SAW sensor with ZnO sensing layer is found to be exhibiting the maximum response towards liquor ammonia as compared to other oxides. The SAW sensor structure showed a peculiar bidirectional shift (increase or decrease) in frequency on exposure to liquor ammonia vapors, while other VOCs (volatile organic compounds) and gases in the presence and absence of water vapors showed poor response indicating the excellent selectivity of the prepared sensors towards ammonia. Further interaction of liquor ammonia is a one step process involving adsorption of ammonia and water vapors simultaneously.

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