Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

On-chip fabrication of high performance nanostructured ZnO UV detectors.

ABSTRACT: Developing rationally controlled bottom-up device fabrication processes is essential for the achievement of high performance optimal devices. We report a controlled, seedless and site-selective hydrothermal technique to fabricate high-performance nanostructured ZnO UV-detectors directly on-chip. We demonstrate that by controlling the nanowire growth process, via tuning the experimental parameters such as the concentration of reactants and the growth time, and by introducing a refresh of the growth solution, the device structure efficiency can be enhanced to significantly improve its performance. The on-chip fabricated bridging nanosyringe ultraviolet detector demonstrates improved sensitivity (~10(5)), nanowatts detectability, and ultrafast response-time (90 ms) and recovery-time (210 ms). The improvement in response-time and recovery-time is attributed to the unique nanowire-nanowire junction barrier dominated resistance and the direct contact between ZnO and Au electrodes. Furthermore, the enhanced sensitivity and nanowatts detectability of the bridging nanosyringe device are due to the reduction in dimensionality and ultrahigh surface-to-volume ratio. This work paves the way toward low cost, large scale, low temperature, seedless and site-selective fabrication of high performance ZnO nanowire sensors on flexible and transparent substrates.

SUBMITTER: Alenezi MR

PROVIDER: S-EPMC4330536 | biostudies-other | 2015

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Role of the Exposed Polar Facets in the Performance of Thermally and UV Activated ZnO Nanostructured Gas Sensors.

Project description:ZnO nanostructures with different morphologies (nanowires, nanodisks, and nanostars) were synthesized hydrothermally. Gas sensing properties of the as-grown nanostructures were investigated under thermal and UV activation. The performance of the ZnO nanodisk gas sensor was found to be superior to that of other nanostructures (S g ∼ 3700% to 300 ppm ethanol and response time and recovery time of 8 and 13 s). The enhancement in sensitivity is attributed to the surface polarities of the different structures on the nanoscale. Furthermore, the selectivity of the gas sensors can be achieved by controlling the UV intensity used to activate these sensors. The highest sensitivity value for ethanol, isopropanol, acetone, and toluene are recorded at the optimal UV intensity of 1.6, 2.4, 3.2, and 4 mW/cm(2), respectively. Finally, the UV activation mechanism for metal oxide gas sensors is compared with the thermal activation process. The UV activation of analytes based on solution processed ZnO structures pave the way for better quality gas sensors.

| S-EPMC3759168 | biostudies-other

High performance platinum contacts on high-flux CdZnTe detectors.

Project description:The need for direct X-ray detection under high photon flux with moderate or high energies (30-100 keV range) has strongly increased with the rise of the 4th Generation Synchrotron Light Sources, characterised by extremely brilliant beamlines, and of other applications such as spectral computed tomography in medicine and non-destructive tests for industry. The novel Cadmium Zinc Telluride (CZT) developed by Redlen Technologies can be considered the reference material for high-flux applications (HF-CZT). The enhanced charge transport properties of the holes allow the mitigation of the effects of radiation induced polarization phenomena, typically observed in standard CZT materials (LF-CZT) under high photon flux. However, standard LF-CZT electrical contacts led to inacceptable high dark leakage currents on HF-CZT devices. In this work, a detailed study on the characteristics of new optimized sputtered platinum electrical contacts on HF-CZT detectors is reported. The results from electrical and spectroscopic investigations, showed the best performances on HF-CZT detectors with platinum anode, coupled with both platinum or gold cathode. The morphology, structure, and composition of Pt/CZT contact have been analysed by means of Transmission Electron Microscopy (TEM) on microscopic lamellas obtained by Focused Ion Beam (FIB), highlighting the presence of CdTeO3 oxide at the metal semiconductor interface.

| S-EPMC10589347 | biostudies-literature

Visible and UV photo-detection in ZnO nanostructured thin films via simple tuning of solution method.

Project description:This study demonstrates significant visible light photo-detection capability of pristine ZnO nanostructure thin films possessing substantially high percentage of oxygen vacancies [Formula: see text] and zinc interstitials [Formula: see text], introduced by simple tuning of economical solution method. The demonstrated visible light photo-detection capability, in addition to the inherent UV light detection ability of ZnO, shows great dependency of [Formula: see text] and [Formula: see text] with the nanostructure morphology. The dependency was evaluated by analyzing the presence/percentage of [Formula: see text] and [Formula: see text] using photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS) measurements. Morphologies of ZnO viz. nanoparticles (NPs), nanosheets (NSs) and nanoflowers (NFs), as a result of tuning of synthesis method contended different concentrations of defects, demonstrated different photo-detection capabilities in the form of a thin film photodetector. The photo-detection capability was investigated under different light excitations (UV; 380~420 nm, white ; λ > 420 nm and green; 490~570 nm). The as fabricated NSs photodetector possessing comparatively intermediate percentage of [Formula: see text] ~ 47.7% and [Formula: see text] ~ 13.8% exhibited superior performance than that of NPs and NFs photodetectors, and ever reported photodetectors fabricated by using pristine ZnO nanostructures in thin film architecture. The adopted low cost and simplest approach makes the pristine ZnO-NSs applicable for wide-wavelength applications in optoelectronic devices.

| S-EPMC5678174 | biostudies-literature

Facile fabrication of self-assembled ZnO nanowire network channels and its gate-controlled UV detection.

Project description:We demonstrate a facile way to fabricate an array of gate-controllable UV sensors based on assembled zinc oxide nanowire (ZnO NW) network field-effect transistor (FET). This was realized by combining both molecular surface programmed patterning and selective NW assembly on the polar regions avoiding the nonpolar regions, followed by heat treatment at 300 °C to ensure stable contact between NWs. The ZnO NW network FET devices showed typical n-type characteristic with an on-off ratio of 105, transconductance around 47 nS, and mobility around 0.175 cm2 V-?1 s-?1. In addition, the devices showed photoresponsive behavior to UV light that can be controlled by the applied gate voltage. The photoresponsivity was found to be linearly proportional to the channel voltage Vds, showing maximum photoresponsivity at Vds?=?7 V.

| S-EPMC6305260 | biostudies-literature

Fabrication of Hierarchical ZnO@NiO Core-Shell Heterostructures for Improved Photocatalytic Performance.

Project description:ZnO@NiO core-shell heterostructures with high photocatalytic efficiency and reusability were prepared via electrochemical deposition on carbon fiber cloth substrates. Their photocatalytic properties were investigated by measuring the degradation of rhodamine B and methyl orange (MO) under ultraviolet light irradiation. The photodegradation efficiency of the ZnO@NiO heterostructures toward both dyes was better than those of the pure ZnO nanorods and NiO nanosheets. The higher performance could be attributed to the formation of p-n heterojunction between ZnO and NiO. Especially, the ZnO@NiO heterostructure formed upon deposition of NiO for 10 min degraded 95% of MO under ultraviolet light irradiation for 180 min. The high photodegradation efficiency of the ZnO@NiO heterostructures was also attributed to the high separation efficiency of photogenerated carriers, as confirmed by the higher photocurrent of the ZnO@NiO heterostructures (eightfold) when compared with that of the pure ZnO nanorods. Moreover, the high photodegradation efficiency of the ZnO@NiO heterostructures was maintained over three successive degradation experiments and decreased to 90% after the third cycle.

| S-EPMC6117222 | biostudies-literature

Fabrication of ZnO nanoarchitectured fluorine-free robust superhydrophobic and UV shielding polyester fabrics for umbrella canopies.

Project description:Mechanically robust, durable, fluorine-free superhydrophobic and UV shielding surfaces are fabricated on polyester umbrella canopy fabrics by self-assembly of stearic acid on zinc oxide (ZnO) nanoarchitectures on polyester fabrics. Drawbacks of conventional umbrella canopies including rain water penetration through the canopy during heavy rains, wet canopies taking too long to dry, and limited blockage of harmful UV radiation have been overcome with the surface modified canopy fabrics in the present study. Herein, in the typical synthesis, the polyester fabric is dipped in Zn(NO3)2 : hexamethylenetetraamine (HMT), at 1 : 1 molar ratio solution and heated at 100 °C for 2 h to grow ZnO nanoarchitectures on the fabric surface. Stearic acid is allowed to self-assemble by dipping the fabric in 1 g dm-3 stearic acid solution. The modified fabrics are characterized using scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and X-ray fluorescence spectroscopic techniques. The modified fabrics show superhydrophobicity characterized by water contact angles over 150° with the optimum analyzed conditions. The superhydrophobic layer formed on the fabric is resistant to acid rain and stayed durable throughout 50 abrasion cycles and under 1.5 h strong surfactant washing. The developed method is useful to fabricate a smart umbrella canopy with acid rain resistant, durable, robust superhydrophobic and UV blocking properties.

| S-EPMC9085625 | biostudies-literature

Crystallization of ZnO thin films via thermal dissipation annealing method for high-performance UV photodetector with ultrahigh response speed.

Project description:ZnO-based ultraviolet (UV) photodetector can be easily fabricated by using sol-gel spin-coating method, however, the crystallization of amorphous state ZnO thin films is necessary to fabricate high performance UV photodetector. Thus, we devised a thermal dissipation annealing (TDA) method in which the heat transfer to the ZnO thin films can be synchronized with the heat release from the substrate. It was found that sol-gel spin-coated ZnO thin films can be crystallized through the mobility difference of ZnO molecules placed at the surface of ZnO thin films. Also, UV photodetector based on ZnO thin films annealed with the TDA method exhibited faster rise and decay time constant (τr = 35 ms and τd = 73 ms, respectively), a higher on/off current ratio, and reproducible photocurrent characteristics compared to that of the ZnO thin films annealed by using furnace and IR lamp. Therefore, these results indicated that the TDA method is a feasible alternative route for the fabrication of ZnO based high performance optoelectronic devices.

| S-EPMC7801514 | biostudies-literature

High UV and Sunlight Photocatalytic Performance of Porous ZnO Nanostructures Synthesized by a Facile and Fast Microwave Hydrothermal Method.

Project description:The degradation of organic pollutants in wastewaters assisted by oxide semiconductor nanostructures has been the focus of many research groups over the last decades, along with the synthesis of these nanomaterials by simple, eco-friendly, fast, and cost-effective processes. In this work, porous zinc oxide (ZnO) nanostructures were successfully synthesized via a microwave hydrothermal process. A layered zinc hydroxide carbonate (LZHC) precursor was obtained after 15 min of synthesis and submitted to different calcination temperatures to convert it into porous ZnO nanostructures. The influence of the calcination temperature (300, 500, and 700 °C) on the morphological, structural, and optical properties of the ZnO nanostructureswas investigated. All ZnO samples were tested as photocatalysts in the degradation of rhodamine B (RhB) under UV irradiation and natural sunlight. All samples showed enhanced photocatalytic activity under both light sources, with RhB being practically degraded within 60 min in both situations. The porous ZnO obtained at 700 °C showed the greatest photocatalytic activity due to its high crystallinity, with a degradation rate of 0.091 and 0.084 min-1 for UV light and sunlight, respectively. These results are a very important step towards the use of oxide semiconductors in the degradation of water pollutants mediated by natural sunlight.

| S-EPMC8125317 | biostudies-literature

Efficient Removal of Methylene Blue and Ciprofloxacin from Aqueous Solution Using Flower-like, Nanostructured ZnO Coating under UV Irradiation.

Project description:Flower-like ZnO architectures assembled with many nanorods were successfully synthesized through Thermionic Vacuum Arc, operated both in direct current (DC-TVA) and a pulsed mode (PTVA), and coupled with annealing in an oxygen atmosphere. The prepared coatings were analysed by scanning-electron microscopy with energy-dispersive X-ray-spectroscopy (SEM-EDX), X-ray-diffraction (XRD), and photoluminescence (PL) measurements. By simply modifying the TVA operation mode, the morphology and uniformity of ZnO nanorods can be tuned. The photocatalytic performance of synthesized nanostructured ZnO coatings was measured by the degradation of methylene-blue (MB) dye and ciprofloxacin (Cipro) antibiotic. The ZnO (PTVA) showed enhancing results regarding the photodegradation of target contaminants. About 96% of MB molecules were removed within 60 min of UV irradiation, with a rate constant of 0.058 min-1, which is almost nine times higher than the value of ZnO (DC-TVA). As well, ZnO (PTVA) presented superior photocatalytic activity towards the decomposition of Cipro, after 240 min of irradiation, yielding 96% degradation efficiency. Moreover, the agar-well diffusion assay performance against both Gram-positive and Gram-negative bacteria confirms the degradation of antibiotic molecules by the UV/ZnO (PTVA) approach, without the formation of secondary hazardous products during the photocatalysis process. Repeated cyclic usage of coatings revealed excellent reusability and operational stability.

| S-EPMC9267983 | biostudies-literature

Shim-on-Chip Design for Microfluidic NMR Detectors.

Project description:In this contribution we present a novel system for shimming capillary samples such as used in microfluidic NMR probe heads. Due to the small sample size, shimming microliter samples using regular shim coils is complicated. Here we demonstrate the use of a series of parallel wires placed perpendicular to B0 as a Shim-on-Chip shim system. This is achieved by placing a ribbon flat cable horizontally over the NMR detector, in our case a stripline. The current through each wire of the ribbon cable can be controlled independently employing a 16 channel DAC. This makes for a simple, cheap, and easy to construct alternative to regular shim systems. The Shim-on-Chip is, nevertheless, quite flexible in creating a magnetic field which matches the inhomogeneity of the magnet in one dimension. The capillary sample geometry is well suited for this type of shimming since its length is much larger than its width. With this Shim-on-Chip system we have reached line widths of 2.2 Hz (at 50%) and 27 Hz (at 0.55%) on a 144 MHz NMR spectrometer without any other room temperature shims. Unlike regular shims, the Shim-on-Chip is located inside the NMR probe. It is always centered on the NMR sample, because of this the shims have an intuitive effect on the line shape. Therefore, the manual shimming is simpler when compared to a regular shim system, as it is difficult to position a microliter sample in the exact center of the shim coils. We furthermore demonstrate the use of a Shim-on-Chip method in a 400 MHz Rapid-Melt DNP system. Decent line widths were achieved even for a sample which is located off-center inside the NMR magnet.

| S-EPMC6127796 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data