Highly Responsive Behavior Towards Acetone by WO 3 Based Bottom Gate Field Effect Transistor
01 Oct 2018-
TL;DR: In this article, the performance of a nanostructured tungsten trioxide (WO 3 ) based bottom gate field effect transistor as a highly responsive gas sensor is presented.
Abstract: This paper presents the performance of a nanostructured tungsten trioxide (WO 3 ) based bottom gate field effect transistor as a highly responsive gas sensor. The fabrication process followed is scalable and semiconductor industry compatible. Complete material and electrical characterization of the device was performed which shows WO 3 nano-clusters and ambipolar nature of the WO 3 based transistor. Sensing studies were carried out in presence of volatile organic compounds (VOCs) of which maximum response was given to acetone. Dynamic response was taken to demonstrate real time sensing.
References
More filters
TL;DR: Mesoporous WO3 films with a lamellar structure have been synthesized by electrodeposition using sodium dodecyl sulfate (SDS) as a templating agent as mentioned in this paper.
Abstract: Mesoporous WO3 films with a lamellar structure (see Figure) have been synthesized by electrodeposition using sodium dodecyl sulfate (SDS) as a templating agent. Compared to non-porous WO3 prepared with isopropanol instead of SDS, lamellar phase mesoporous WO3 showed higher photocatalytic activity and greater current density for hydrogen intercalation, probably due to the larger surface area of mesoporous WO3 and more facile charge transport.
449 citations
"Highly Responsive Behavior Towards ..." refers background in this paper
...Tungsten oxides are a group of materials that have numerous intriguing chemical and physical properties, which make these suitable candidates for a variety of different applications like, chemical sensing devices [3-7], electro-chromic devices [8], field emitters [9,10]....
[...]
TL;DR: In this paper, thin films of tungsten oxide were deposited on SnO2:F coated glass using pulsed laser deposition using Raman spectroscopy, and the decrease of the optical band gap was ascribed to a decrease of WO/O-W −W −O ratio correlated to an increase of the cluster size of tengsten oxide with crystallinity.
242 citations
TL;DR: In this paper, the gasochromic response of WO3 nanotextured thin films coated with a 2.5-nm catalytic Pt layer upon exposure to hydrogen (H2) gas was investigated.
Abstract: The gasochromic response of WO3 nanotextured thin films coated with a 2.5 nm catalytic Pt layer upon exposure to hydrogen (H2) gas was investigated. The Pt/WO3 thin films exhibited gasochromic characteristics, when measured in the visible-NIR (400–900 nm) range. The total absorbance in this range increased approximately 15% when exposed to 0.06% H2 gas in synthetic air. Similarly, a 60% increase was measured to an exposure of 1% H2 gas in synthetic air. However, this response was reduced by approximately 40% when exposed to the same concentration of H2 gas in air with humidity of 6%. These measurements were conducted over a range of temperatures with extensive analysis preformed at both room temperature and 100 °C to ascertain the suitability of the films for low power applications. Despite having a comparatively slow recovery time at room temperature, it was observed that these films were highly sensitive, providing stable and repeatable responses towards low concentrations of H2 at 100 °C. Films typically had rapid response and recovery, in the range of few seconds. WO3 thin films were characterized via Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). XRD confirmed the presence of WO3 crystallites with a preferential miller index orientation of (2 0 0), and SEM investigations revealed that the WO3 compact thin films were comprised of nanotextured grains.
149 citations
"Highly Responsive Behavior Towards ..." refers background in this paper
...Tungsten oxides are a group of materials that have numerous intriguing chemical and physical properties, which make these suitable candidates for a variety of different applications like, chemical sensing devices [3-7], electro-chromic devices [8], field emitters [9,10]....
[...]
TL;DR: In this article, the normal coordinates of tetragonal WO3 have been calculated and a correlation of the phase transitions with the critical behaviour of some of the normal modes has been attempted.
Abstract: The Raman spectrum of WO3 has been investigated from -180 to 290°C. An interpretation of the phonon spectra of the phases with higher symmetries is carried out by group theory. The normal coordinates of tetragonal WO3 have been calculated and a correlation of the phase transitions with the critical behaviour of some of the normal modes has been attempted.
142 citations
"Highly Responsive Behavior Towards ..." refers background in this paper
...Tungsten trioxide (WO3), a wide bandgap semiconductor can be crystallized into different crystal structures and phases according to the temperature [11,12]....
[...]
TL;DR: In this paper, an empirical correlation is developed for relating the wavenumbers of (WO) stretching modes to WO bond lengths and bond strength for tungsten oxide reference compounds.
Abstract: An empirical correlation is developed for relating the wavenumbers of (WO) stretching modes to WO bond lengths and bond strengths for tungsten oxide reference compounds. A least-squares exponential fit of crystallographically determined WO bond lengths to the wavenumbers of their Raman stretching modes is presented along with a relation between WO bond strengths, in valence units, and wavenumbers of Raman stretching modes. The empirical bond length/stretching mode wavenumber/bond strength relationships lead to a unique and effective method of interpreting Raman spectra of tungstate species. This method leads to the WO bond lengths and coordination of the tungstate species. The utility of the method is illustrated by estimating the wavenumbers of the Raman stretching modes for the ideal WO4 tetrahedron and WO6 octahedron, and the bonds lengths and coordinations of the tungstate species in the reference compounds Na2WO4, PbWO4, CaWO4 and Bi2WO6. In addition, the WO bond lengths of the WO6 octahedra in crystalline Ba2MgWO6 are reported for the first time. This new approach for evaluating the Raman spectra of tungstate species is expected to be generally applicable to all tungstates, regardless of environment, physical state, or oxidation state.
141 citations
"Highly Responsive Behavior Towards ..." refers background in this paper
...Tungsten trioxide (WO3), a wide bandgap semiconductor can be crystallized into different crystal structures and phases according to the temperature [11,12]....
[...]
...CHARACTERIZATION The surface morphologies of the WO3 nanostructures for the sample were investigated by FESEM and EDX (FEI Quanta 200 FESEM)....
[...]
...2(c) depicts the XRD pattern of WO3 nanostructure in 2θ range of 10 to 90....
[...]
...Samples with nanostructured WO3 film were prepared, and the electrical measurements were taken from Cr/Au electrodes....
[...]
...2(a)) which shows formation of interconnected nanoclusters of WO3....
[...]