Sensing Responses Based on Transfer Characteristics of InAs Nanowire Field-Effect Transistors


  1. Tseng, A.C.
  2. Lynall, D.
  3. Savelyev, I.
  4. Blumin, M.
  5. Wang, S.
  6. Ruda, H.E.
Corporate Authors
Defence Research and Development Canada, Suffield Research Centre, Ralston AB (CAN);Toronto Univ, Toronto ONT (CAN)
Nanowire-based field-effect transistors (FETs) have demonstrated considerable promise for a new generation of chemical and biological sensors. Indium arsenide (InAs), by virtue of its high electron mobility and intrinsic surface accumulation layer of electrons, holds properties beneficial for creating high performance sensors that can be used in applications such as point-of-care testing for patients diagnosed with chronic diseases. Here, we propose devices based on a parallel configuration of InAs nanowires and investigate sensor responses from measurements of conductance over time and FET characteristics. The devices were tested in controlled concentrations of vapour containing acetic acid, 2-butanone and methanol. After adsorption of analyte molecules, trends in the transient current and transfer curves are correlated with the nature of the surface interaction. Specifically, we observed proportionality between acetic acid concentration and relative conductance change, off current and surface charge density extracted from subthreshold behaviour. We suggest the origin of the sensing response to acetic acid as a two-part, reversible acid-base and redox reaction between acetic acid, InAs and its native oxide that forms slow, donor-like states at the nanowire surface. We further describe a simple model that is able to distinguish the occurrence of physical versus chemical adsorption by comparing the values of the extracted surface charge density. These studies demonstrate that
nanowire;chemical and biological;sensor
Report Number
DRDC-RDDC-2017-P081 — External Literature
Date of publication
01 Sep 2017
Number of Pages
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