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Journal of ELECTRONIC MATERIALS, Vol. 46, No. 2, 2017
DOI: 10.1007/s11664-016-5128-7
2016 The Minerals, Metals & Materials Society
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Web End = Simulation and Fabrication of SAW-Based Gas Sensor with Modied Surface State of Active Layer and Electrode Orientation for Enhanced H2 Gas Sensing
MD. NAZIBUL HASAN,1 SANTANU MAITY,2,4 ARGHA SARKAR,1 CHANDAN TILAK BHUNIA,1 DEBABRATA ACHARJEE,1and ANEESH M. JOSEPH3
1.Department of Computer Science and Engineering, National Institute of Technology, Yupia, Arunachal Pradesh 791112, India. 2.Department of Electronics and Communication Engineering, National Institute of Technology, Yupia, Arunachal Pradesh 791112, India. 3.Department of Electrical Engineering, Center of Excellence in Nano Electronics, IIT-Bombay, Powai 400076, India.4.e-mail: [email protected]
The design, analysis, optimization, and fabrication of layered and nanostructure-based surface acoustic wave (SAW) gas sensors are presented. A lithium niobate and zinc oxide (ZnO) nano multilayer structure is proposed to enhance the sensitivity of the SAW-based gas sensor. Different materials are considered for the intermediate layer in the design for optimization purposes. The sensitivity of the sensor could be improved due to increased active surface area obtained by varying the aspect ratio of the nanorods, the thickness of the intermediate layer, and the gap between the electrodes. The total displacement and frequency shift of the device were signicantly improved. Overall, the mechanically engineered surface-based (nanorod) SAW gas sensor offered better sensing response than the layered SAW gas sensor in terms of sensitivity performance.
Key words: Surface acoustic wave, nanorod, sensitivity, hexagonal structure
INTRODUCTION
Surface acoustic wave (SAW) gas sensors are widely used for detection of physical, biological, and chemical quantities due to their high sensitivity, lower insertion loss, and gas monitoring capability,1 representing an interesting basic detection technique in the eld of sensor technology. Their principle of operation relies on the interaction with a propagating acoustic wave, which depends on the sensor response, the linear and nonlinear properties of the propagation medium (including the mass density), the elastic stiffness of the piezoelectric materials applied, and the electricdielectric behavior. Using the
piezoelectric effect, the acoustic wave can be converted into an electrical signal when it passes from the surface of the device substrate to an interdigitated transducer (IDT).2,3
In this study, a SAW-based gas sensor was designed and its performance monitored. The SAW device consisted of...