Patil, S., Sinha, N., Melnik, R.V.N.
Nanoengineering: Fabrication, Properties, Optics, and Devices VI. Proceedings of SPIE, Optics+Photonics, Vol. 7402, Eds. E.A. Dobisz, L.A. Eldada,San Diego, California, USA, ISBN: 9780819476920, pp. 74020C --74020C-8 (8 pages), 2009
We quantify the influence of thermopiezoelectric effects in nano-sized Al[subscript x]Ga[subscript 1-x]N/GaN heterostructures for pressure sensor applications based on the barrier height modulation principle. We use a fully coupled thermoelectromechanical formulation, consisting of balance equations for heat transfer, electrostatics and mechanical field. To estimate the vertical transport current in the heterostructures, we have developed a multi-physics model incorporating thermionic emission, thermionic field emission, and tunneling as the current transport mechanisms. A wide range of thermal (0-300 K) and pressure (0-10 GPa) loadings has been considered. The results for the thermopiezoelectric modulation of the barrier height in these heterostructures have been obtained and optimized. The calculated current shows a linear decrease with increasing pressure. The linearity in pressure response suggests that Al[subscript x]Ga[subscript 1-x]N/GaN heterostructure-based devices are promising candidates for pressure sensor applications under severe environmental conditions.
Keywords: nanotechnology based sensors, mathematical modelling, low dimensional nanostructures, nano pressure sensors