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

Abstract

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 InAs nanowires can produce a multitude of sensor responses for the purpose of developing next generation, multi-dimensional sensor applications.

Microscopic Understanding of the Growth and Structural Evolution of Narrow Bandgap III–V Nanostructures

“…Due to the unique optical and electrical characteristics, III–V semiconductors have been recognized as the extension of Moore’s Law and have shown broad application prospect in infrared light detection [ 1 , 2 ], quantum computation [ 3 ], gas sensing [ 4 ], etc. [ 5 , 6 ].…”

Conductometric Sensing with Individual InAs Nanowires

“…In this context, nanowires (NWs) are emerging as promising platforms for the development of ultrasensitive sensors for the direct detection of biological and chemical species [15,16,17,18]. The large surface-to-volume ratio is considered as one of the key advantages for the increased sensor response of nanowire-based devices [18,19,20,21].…”

“…In this context, nanowires (NWs) are emerging as promising platforms for the development of ultrasensitive sensors for the direct detection of biological and chemical species [15,16,17,18]. The large surface-to-volume ratio is considered as one of the key advantages for the increased sensor response of nanowire-based devices [18,19,20,21]. Different NW materials [20,22,23,24], sensed molecules [21,25,26,27], device architectures [28,29,30], and signal transduction methods [31] are currently being studied.…”

“…The realization of all-electrical devices using semiconducting nanowires as the sensing element is particularly attractive because it enables ready signal transduction and integration into miniaturized systems [15]. The interaction between the NW surface and the adsorbed molecules causes a local modification of the energy band structure in the semiconductor, which affects the electrical transport properties [18]. Nanowires made of different semiconducting materials have been exploited in field effect transistors for sensing applications [20,29,32,33,34], providing useful insights into the understanding of the specific physical mechanisms related to the ability of nanowire devices in detecting different types of analytes.…”

One-Dimensional Nanostructures: Microfluidic-Based Synthesis, Alignment and Integration towards Functional Sensing Devices

“…In the past several years, 1D nanoscale structures including nanowires (NWs), nanotubes (NTs) and nanofibers have drawn great attention due to their superior properties of high surface-to-volume ratio, ultrasmall scale and important applications in nanoscale device generation [ 1 , 2 , 3 , 4 ]. Thus, much effort has been devoted to the formation of 1D nanostructures with uniform morphology, using different kinds of precursors, such as inorganic [ 5 ], organic [ 6 ] or hybrid materials [ 7 ].…”