Title :
Layered SAW nitrogen dioxide sensor based on a ZnO/36° YX LiTaO3 structure with WO3 selective layer
Author :
Ippolito, S.J. ; Kalantar-Zadeh, K. ; Trinchi, A. ; Wlodarski, W. ; Tobar, M.
Author_Institution :
Sch. of Electr. & Comput. Syst. Eng., RMIT Univ., Melbourne, Vic., Australia
Abstract :
A novel layered surface acoustic wave (SAW) device is investigated for gas sensing of low levels NO2 concentrations in air. The results show much higher sensitivity when compared against other SAW devices operating at the same frequency. The sensing structure is based on a layered SAW devices fabricated on a 36° X-cut, Y-propagating LiTaO3 substrate. A ZnO guiding layer is employed to increase sensor sensitivity, whilst a thin film of WO3 provides the selectivity towards NO2. In this paper, the fabrication of the ZnO/36° YX LiTaO3 sensor is described and micro-characterization of the selective layer is presented. Furthermore, a gas sensing experiment reveals the sensitivity of the device.
Keywords :
II-VI semiconductors; gas sensors; lithium compounds; nitrogen compounds; semiconductor growth; semiconductor thin films; sputter deposition; surface acoustic wave sensors; surface morphology; tungsten compounds; wide band gap semiconductors; zinc compounds; LiTaO3; NO2; WO3; WO3 selective layer; WO3 thin film; X-cut Y-propagating LiTaO3 substrate; ZnO guiding layer; ZnO-LaTiO3; gas sensor; layered SAW nitrogen dioxide sensor; layered surface acoustic wave device; sensitivity; surface morphology; Acoustic sensors; Acoustic waves; Frequency; Gas detectors; Nitrogen; Substrates; Surface acoustic wave devices; Surface acoustic waves; Thin film sensors; Zinc oxide;
Conference_Titel :
Frequency Control Symposium and PDA Exhibition Jointly with the 17th European Frequency and Time Forum, 2003. Proceedings of the 2003 IEEE International
Print_ISBN :
0-7803-7688-9
DOI :
10.1109/FREQ.2003.1275215
