skip to main content

SciTech ConnectSciTech Connect

Title: Viscosity-dependent drain current noise of AlGaN/GaN high electron mobility transistor in polar liquids

The drain current fluctuation of ungated AlGaN/GaN high electron mobility transistors (HEMTs) measured in different fluids at a drain-source voltage of 0.5 V was investigated. The HEMTs with metal on the gate region showed good current stability in deionized water, while a large fluctuation in drain current was observed for HEMTs without gate metal. The fluctuation in drain current for the HEMTs without gate metal was observed and calculated as standard deviation from a real-time measurement in air, deionized water, ethanol, dimethyl sulfoxide, ethylene glycol, 1,2-butanediol, and glycerol. At room temperature, the fluctuation in drain current for the HEMTs without gate metal was found to be relevant to the dipole moment and the viscosity of the liquids. A liquid with a larger viscosity showed a smaller fluctuation in drain current. The viscosity-dependent fluctuation of the drain current was ascribed to the Brownian motions of the liquid molecules, which induced a variation in the surface dipole of the gate region. This study uncovers the causes of the fluctuation in drain current of HEMTs in fluids. The results show that the AlGaN/GaN HEMTs may be used as sensors to measure the viscosity of liquids within a certain range of viscosity.
Authors:
; ; ; ; ; ; ; ; ;  [1] ; ;  [2] ;  [3] ;  [4] ;  [5]
  1. Institute of Nanoengineering and Microsystems, National Tsing Hua University, Hsinchu 300, Taiwan (China)
  2. Department of Electrical engineering, National Central University, Jhongli City, Taoyuan County 32001, Taiwan (China)
  3. Division of Medical Engineering, National Health Research Institutes, MiaoLi, Taiwan (China)
  4. Department of Biomedical Engineering and Environmental Science, National Tsing Hua University, Hsinchu 300, Taiwan (China)
  5. Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611 (United States)
Publication Date:
OSTI Identifier:
22258740
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 20; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BROWNIAN MOVEMENT; BUTANEDIOLS; DIPOLE MOMENTS; DIPOLES; DMSO; ELECTRIC CURRENTS; ELECTRIC POTENTIAL; ELECTRON MOBILITY; ETHANOL; FLUCTUATIONS; GALLIUM NITRIDES; GLYCEROL; METALS; TIME MEASUREMENT; TRANSISTORS; VISCOSITY