Large-scale, single-oriented ZnO nanostructure on h-BN films for flexible inorganic UV sensors

Low-cost and large-scale production techniques for flexible electronics have evolved greatly in recent years, having great impact in applications such as wearable technology and the internet of things. In this work, we demonstrate fully screen-printed UV photodetectors, successfully fabricated at a low temperature on a cork substrate, using as the active layer a mixture of zinc oxide nanoparticles and ethylcellulose. The photoresponse under irradiation with a UV lamp with peak emission at 302 nm exhibited a quasi-quadratic behavior directly proportional to the applied voltage, with a photocurrent of about 5.5 and 20 μA when applying 1.5 V and 5 V, respectively. The dark current stayed below 150 nA, while the rise and falling times were, respectively, below 5 and 2 s for both applied voltages. The performance was stable over continuous operation and showed a degradation of only 9% after 100 bending cycles in a 45 mm radius test cylinder. These are promising results regarding the use of this type of sensor in wearable applications such as cork hats, bracelets, or bags.

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STRUCTURAL AND OPTICAL PROPERTIES OF LARGE-SCALE ZnO NANOWIRES AND NANOSHEETS PREPARED BY DRY THERMAL OXIDATION

Surface Review and Letters ◽

10.1142/s0218625x09013451 ◽

2009 ◽

Vol 16 (06) ◽

pp. 901-904 ◽

Cited By ~ 6

Author(s):

S. S. TNEH ◽

H. ABU HASSAN ◽

K. G. SAW ◽

F. K. YAM ◽

Z. HASSAN

Keyword(s):

Optical Properties ◽

Thermal Oxidation ◽

Large Scale ◽

Gas Flow ◽

Deep Level ◽

Exciton Peak ◽

Interstitial Oxygen ◽

Energy Dispersion Spectroscopy ◽

Zno Nanostructure ◽

Annealing Conditions

In this work, we report the morphology and optical properties of zinc oxide ( ZnO ) layers prepared by dry thermal oxidation at different annealing conditions. Morphology studies using scanning electron microscope (SEM) show that the amount of nanowires and nanosheets increases with the introduction of a flow of O2 gas. High-resolution X-ray diffraction (HR-XRD) data show that typical polycrystalline ZnO nanostructure layers have been deposited. Near-perfect stoichiometry of Zn and O atom vacancies has been observed from energy dispersion spectroscopy (EDS) spectrum. Photoluminescence (PL) spectra show strong peaks at UV and green regions. An increase in the stoichiometry of ZnO has been achieved with the oxygen gas flow during annealing indicating that deep-level defects represented by interstitial oxygen and antisite oxygen are gas pressure dependent. A single exciton peak with binding energy 60 meV has been observed at room temperature.

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Photoconductivity Dependence on the Background Oxygen Pressure in Nanostructured ZnO UV Sensor

MRS Proceedings ◽

10.1557/proc-1178-aa09-28 ◽

2009 ◽

Vol 1178 ◽

Author(s):

Nilima V Hullavarad ◽

Shiva S Hullavarad

Keyword(s):

Electronic Properties ◽

Vapor Phase ◽

Oxygen Pressure ◽

Zno Nanowires ◽

Zno Nanostructures ◽

Uv Sensor ◽

Zno Nanostructure ◽

Uv Sensors

AbstractThe present work describes the photoconductivity dependence on ZnO nanostructure UV sensor. ZnO nanostructures were synthesized by direct vapor phase (DVP) technique. ZnO nanowires are of dimensions 30-65 nm in diameter and 5 μm in length. The role of oxygen in deciding the opto-electronic properties of nanostructured ZnO UV sensors was studied.

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Electrochemical Synthesis for Uniform and Large-Scale Zinc Oxide Nano Structure Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.194-196.429 ◽

2011 ◽

Vol 194-196 ◽

pp. 429-435

Author(s):

Wen Zhang ◽

Yong Ning He ◽

Wu Yuan Cui ◽

Cheng Bo Zhou

Keyword(s):

Electron Microscopy ◽

Zinc Oxide ◽

Indium Tin Oxide ◽

Large Scale ◽

Deposition Time ◽

Zno Films ◽

Nano Structure ◽

Zno Nanostructure ◽

Ito Glass ◽

Flake Structure

Three different kinds of zinc oxide (ZnO) nanostructure films have been synthesized on an indium tin oxide (ITO) glass substrate by electrochemical method with adjusting the concentration of the electrolyte, deposition time and temperature. X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM) and photoluminescence (PL) spectrum have been used to determine the characteristics of these nanostructures. The results show that concentration of the electrolyte is one of the most important factors that determine the morphologies of ZnO films. Nanobuds, nanorods, flakes are obtained with the electrolyte concentration increasing. Nanobuds and nanorods have no significant changes with the deposition time prolonged while the flakes grow bigger and thicker. The flakes merge together at high temperature while nanobuds remain unchanged except getting larger and sparser. Nanobuds and nanorods show single crystal patterns while the flakes are composted by multi crystals. The reasons forming such different morphology were discussed according to crystal growth theory. The PL spectra of these ZnO films are quite different according to various microstructures. The film with flake structure has a significant widen near edge emission peak with the depressed visible emission, which may have potential applications on optoelectronic devices and sensors.

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Surface enhanced lithography with adhesion agent to achieve large-scale ZnO nanostructure on stainless steel substrate

Functional Materials Letters ◽

10.1142/s1793604718500844 ◽

2018 ◽

Vol 11 (04) ◽

pp. 1850084 ◽

Cited By ~ 2

Author(s):

Qiang Ma ◽

Min Zhu ◽

Yuzhen Zhao ◽

Siyi Ding ◽

Shaopeng Tian ◽

...

Keyword(s):

Stainless Steel ◽

Photoelectron Spectroscopy ◽

Large Scale ◽

Steel Substrate ◽

Vital Role ◽

Secondary Phases ◽

Zno Film ◽

Zno Nanostructure ◽

Potassium Acid Phthalate ◽

Acid Phthalate

We present a novel point of view to fabricate an enhanced stability controllable growing, large-scale, direct, fast and template assisted nanostructure ZnO with twin –OH group terminated of compound containing –OH group by electrochemical deposition (ECD). In this paper, the collected potassium acid phthalate with twin –OH group was printed to form a matrix as template to synthesize a ZnO nanostructure. Structural analyses showed that the ZnO nanostructure is wurtzite in structure, without any secondary phases. Various features of Raman mapping and X-ray photoelectron spectroscopy of the as-prepared ZnO were found to mark variety of the characteristic of the as-prepared ZnO before and after tape test. A direct link between growing ZnO and potassium acid phthalate with twin –OH group was established, suggesting that this special twin –OH group between nanostructure ZnO and substrate (stainless steel) plays a vital role in forming a firm nanostructure ZnO film on the surface of the substrate. Furthermore, we raised a mechanism to explicate the functional process of twin –OH group on ZnO film. We believe that this facile method to fabricate a controllable nanostructure ZnO here is equally applicable to other semiconductors which are critical in optoelectronics, lasing and luminescence applications.

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Economic Friendly ZnO-Based UV Sensors Using Hydrothermal Growth: A Review

Materials ◽

10.3390/ma14154083 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4083

Author(s):

Liguo Qin ◽

Fagla Jules Mawignon ◽

Mehboob Hussain ◽

Nsilani Kouediatouka Ange ◽

Shan Lu ◽

...

Keyword(s):

Hydrothermal Synthesis ◽

Low Temperature ◽

Low Cost ◽

Economic Cost ◽

Pollution Monitoring ◽

High Yield ◽

Growth Time ◽

Zno Nanostructure ◽

Yield Production ◽

Uv Sensors

Ultraviolet (UV) sensors offer significant advantages in human health protection and environmental pollution monitoring. Amongst various materials for UV sensors, the zinc oxide (ZnO) nanostructure is considered as one of the most promising candidates due to its incredible electrical, optical, biomedical, energetic and preparing properties. Compared to other fabricating techniques, hydrothermal synthesis has been proven to show special advantages such as economic cost, low-temperature process and excellent and high-yield production. Here, we summarize the latest progress in research about the hydrothermal synthesis of ZnO nanostructures for UV sensing. We particularly focus on the selective hydrothermal processes and reveal the effect of key factors/parameters on ZnO architectures, such as the laser power source, temperature, growth time, precursor, seeding solution and bases. Furthermore, ZnO hydrothermal nanostructures for UV applications as well as their mechanisms are also summarized. This review will therefore enlighten future ideas of low-temperature and low-cost ZnO-based UV sensors.

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Gallium oxide nanowires for UV detection with enhanced growth and material properties

Scientific Reports ◽

10.1038/s41598-020-78326-x ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Badriyah Alhalaili ◽

Ryan James Bunk ◽

Howard Mao ◽

Hilal Cansizoglu ◽

Ruxandra Vidu ◽

...

Keyword(s):

High Temperatures ◽

Gallium Oxide ◽

Large Scale ◽

Uv Light ◽

Volume Ratio ◽

Scale Production ◽

Oxide Nanowires ◽

Optimum Configuration ◽

Large Scale Production ◽

Uv Sensors

AbstractIn the last decade, interest in the use of beta gallium oxide (β-Ga2O3) as a semiconductor for high power/high temperature devices and deep-UV sensors has grown. Ga2O3 has an enormous band gap of 4.8 eV, which makes it well suited for these applications. Compared to thin films, nanowires exhibit a higher surface-to-volume ratio, increasing their sensitivity for detection of chemical substances and light. In this work, we explore a simple and inexpensive method of growing high-density gallium oxide nanowires at high temperatures. Gallium oxide nanowire growth can be achieved by heating and oxidizing pure gallium at high temperatures (~ 1000 °C) in the presence of trace amounts of oxygen. This process can be optimized to large-scale production to grow high-quality, dense and long Ga2O3 nanowires. We show the results of morphological, structural, electrical and optical characterization of the β-Ga2O3 nanowires including the optical bandgap and photoconductance. The influence of density on these Ga2O3 nanowires and their properties will be examined in order to determine the optimum configuration for the detection of UV light.

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Synthesis of Lotus-Leaf-Shaped and Four-Footed ZnO Nanostructure on a Large Scale

Japanese Journal of Applied Physics ◽

10.1143/jjap.48.091101 ◽

2009 ◽

Vol 48 (9) ◽

pp. 091101 ◽

Cited By ~ 3

Author(s):

Yuefu Zhang ◽

Yuguo Li ◽

Jingyao Zhang ◽

Chuanwen Cui

Keyword(s):

Large Scale ◽

Lotus Leaf ◽

Zno Nanostructure

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Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

International Astronomical Union Colloquium ◽

10.1017/s0252921100031493 ◽

1999 ◽

Vol 173 ◽

pp. 243-248

Author(s):

D. Kubáček ◽

A. Galád ◽

A. Pravda

Keyword(s):

Image Processing ◽

Large Scale ◽

Harvard College ◽

Oak Ridge ◽

Large Scale Structures ◽

Short Period Comet ◽

Short Period ◽

Scale Structures ◽

Harvard College Observatory ◽

Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

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