scholarly journals Nanorod Arrays Enhanced UV Light Response of Mg-Doped ZnO Films

Symmetry ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1005
Author(s):  
Der-Yuh Lin ◽  
Hone-Zern Chen ◽  
Ming-Cheng Kao ◽  
San-Lin Young ◽  
Wen-Yi Sung
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Light Response ◽  
Band Gap Energy ◽  
Zno Films ◽  
Silicon Substrates ◽  
Nanorod Arrays ◽  
Nanocrystalline Films ◽  
Uv Illumination ◽  
Surface Morphologies

Zn1−xMgxO (x = 0, 0.03, 0.05, and 0.07) nanocrystalline films were grown on silicon substrates using the sol–gel method. Furthermore, Zn1−xMgxO vertically aligned hexagonal symmetrical nanorods with six reflection symmetries were fabricated on pure ZnO-seeded layer n-type silicon substrates via a low-temperature hydrothermal method to enhance the ultraviolet (UV) light response. The crystal microstructures and surface morphologies of nanocrystalline films and nanorod arrays were determined by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Transmission spectra showed that the increasing Mg content will increase the band gap energy from 3.28 to 3.46 eV. However, the current–voltage curves in the dark and under UV illumination showed that the UV response did not improve by the incorporation of magnesium. We changed the flat surface of films into symmetrical nanorod arrays and demonstrated they can significantly enhance the normalized photo-to-dark-current ratio up to ten times.

Zinc Oxide Thin Film Synthesized by Sol-Gel Method

2020 ◽  
Vol 307 ◽  
pp. 51-57
Author(s):  
Amna Afiqah Nasution Hakim ◽  
Affa Rozana Abdul Rashid ◽  
N. Arsad ◽  
Aisyah Hanim Surani
Keyword(s):  
Thin Film ◽  
Uv Light ◽  
Zinc Acetate Dihydrate ◽  
Sol Gel ◽  
Dip Coating ◽  
Oxide Thin Film ◽  
Gel Method ◽  
Sol Gel Method ◽  
Crystallite Sizes ◽  
Surface Morphologies

ZnO thin films have been prepared by the dip coating sol gel method. Zinc acetate dihydrate, 2-methoxyethanol and monoethanolamine (MEA) were used as precursor, solvent and stabilizer respectively. The synthesized sample was coated on glass substrate as the molarity of the solution was kept constant at 0.1 M. The structural properties and surface morphologies of ZnO thin film were characterized by XRD and FESEM. The optical properties such as transmittance, absorbance, reflectance and refractive index were studied by using UV-Vis. The functional group of the synthesized sample were verified by using FTIR. Average crystallite sizes of the samples were calculated by using Debye-Scherrer's formula. Next, ZnO is coated on POF in order to examine the reaction towards UV light.

Preparation and Photocatalytic Properties of La, Ce and Nonmetal N Co-Doped TiO2

2016 ◽  
Vol 680 ◽  
pp. 193-197
Author(s):  
San Ti Yi ◽  
Si Qin Zhao
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Uv Light ◽  
Sol Gel ◽  
Light Response ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Co Doped

TiO2, 1%La/TiO2, 1%Ce/TiO2 and a series of Laand Ce co-doped TiO2 photocatalysts were prepared by sol-gel method. Using sol-gel method combine with hydrothermal method prepared rare earth La, Ce and nitrogen co-doped TiO2 photocatalysts. The microstructure, spectroscopy performance and ion doped form of prepared samples were characterized by X-ray powder diffraction (XRD), UV-Vis diffuse reflectance spectroscopy techniques and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of doped TiO2 were examined by measuring the photodegradation of methyl orange. The results showed that the products were all anatase TiO2 nano powder, doping Laor Cehinder the growth of TiO2 particle, further more, doping Laand Cetogether hinder the growth of TiO2 particle more effective, doping N broaden the light response range of TiO2 photocatalyst. At the same time, the photocatalytic activity results indicated that the prepared samples showed superior UV light photocatalytic activity, the sample 1% (La:Ce,9:1)-N/TiO2 showed the highest UV-vis photocatalytic activity.

NANOCRYSTALLINE ALUMINUM DOPED ZINC OXIDE COATED FIBER OPTIC FOR ULTRAVIOLET DETECTION

2013 ◽  
Vol 22 (03) ◽  
pp. 1350037 ◽  
Author(s):  
A. R. A. RASHID ◽  
P. S. MENON ◽  
S. SHAARI
Keyword(s):  
Refractive Index ◽  
Fiber Optic ◽  
Uv Light ◽  
Sol Gel ◽  
Hexagonal Wurtzite Structure ◽  
Zno Films ◽  
Coated Fiber ◽  
Aluminum Doped Zinc Oxide ◽  
Doped Zno

In this paper, we report the fabrication and characterization of an ultraviolet sensing by using Al -doped ZnO films coated on quartz slide and silica fiber optic. Undoped ZnO , 0.5, 1, 2 and 3 at.% of Al were prepared by sol–gel method with annealing temperature of 400°C for 1 h. The presence of spherical shaped nanoparticles and hexagonal (wurtzite) structure were detected for Al doped ZnO by using FESEM and XRD. The band gap values increased by adding Al due to the increment of carrier concentration. I–V curves reveal an ohmic line and improvement in electrical conductivity when the samples are illuminated by ultraviolet (UV) light with a wavelength of 365 nm. At 1 at.% of Al , the film have a larger increment in photocurrent response when illuminated with UV light compared to undoped ZnO and higher concentration (2 at.% and 3 at.%) of Al . For coated fiber optic, the fiber operates under leaky mode and the refractive index of ZnO is decreasing under UV radiation. There is a small drop in output intensity and increased abruptly which depends on the changes of ZnO refractive index. The thin films have a longer recovery time than response time.

scholarly journals Electrical, dielectric and photocatalytic properties of Fe-doped ZnO nanomaterials synthesized by sol gel method

2016 ◽  
Vol 10 (3) ◽  
pp. 125-135 ◽  
Author(s):  
Yacine Cherifi ◽  
Ahcène Chaouchi ◽  
Yannick Lorgoilloux ◽  
Mohammed Rguiti ◽  
Abdelaziz Kadri ◽  
...  
Keyword(s):  
Single Phase ◽  
Uv Light ◽  
Sol Gel ◽  
Complex Impedance ◽  
Hexagonal Wurtzite Structure ◽  
Band Gap Energy ◽  
Cbh Model ◽  
Gap Energy ◽  
Gel Technique ◽  
Doped Zno

Fe-doped ZnO nanoparticles were synthesized by sol gel technique. Fine-scale and single phase hexagonal wurtzite structure in all samples were confirmed by SEM and XRD, respectively. The band gap energy depends on the amount of Fe and was found to be in the range of 3.11-2.53 eV. The electric and dielectric properties were investigated using complex impedance spectroscopy. AC conductivity data were correlated with the barrier hopping (CBH) model to evaluate the binding energy (Wm), the minimum hopping distance (Rmin) and the density of states at Fermi level, N(EF). Fe doping in ZnO also improved the photocatalytic activity. Thus, the sample Zn0.95Fe0.05O showed high degradation potential towards methylene blue (MB), i.e. it degrades 90% of BM in 90min under UV light.

scholarly journals ZnO Films Incorporation Study on Macroporous Silicon Structure

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3697
Author(s):  
Lizeth Martínez ◽  
Godofredo García-Salgado ◽  
Francisco Morales-Morales ◽  
Bernardo Campillo ◽  
Angélica G. Hernández ◽  
...  
Keyword(s):  
Sol Gel ◽  
Ultrasonic Spray Pyrolysis ◽  
Xrd Analysis ◽  
Hybrid Nanostructures ◽  
Root Mean Square Roughness ◽  
Zno Films ◽  
Silicon Substrates ◽  
Macroporous Silicon ◽  
Ultrasonic Spray ◽  
Order Of Magnitude

In the present work, we developed hybrid nanostructures based on ZnO films deposited on macroporous silicon substrates using the sol–gel spin coating and ultrasonic spray pyrolysis (USP) techniques. The changes in the growth of ZnO films on macroporous silicon were studied using a UV-visible spectrometer, an X-ray diffractometer (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). XRD analysis revealed the beneficial influence of macroporous silicon on the structural properties of ZnO films. SEM micrographs showed the growth and coverage of ZnO granular and flake-like crystals inside the pores of the substrate. The root mean square roughness (RMS) measured by AFM in the ZnO grown on the macroporous silicon substrate was up to one order of magnitude higher than reference samples. These results prove that the methods used in this work are effective to cover porous and obtain nano-morphologies of ZnO. These morphologies could be useful for making highly sensitive gas sensors.

Acid Surface Treatment of Sol-Gel Derived ZnO Thin Films for Anti-Reflection Coating Application

2016 ◽  
Vol 675-676 ◽  
pp. 177-180
Author(s):  
Warut Khamon ◽  
Wisanu Pecharapa
Keyword(s):  
Spin Coating ◽  
Sol Gel ◽  
Wet Etching ◽  
Zno Thin Films ◽  
Etching Time ◽  
Zno Films ◽  
Coating Application ◽  
Reflective Layer ◽  
Structure Surface ◽  
Surface Morphologies

Transparent ZnO films were deposited by sol-gel spin coating process. HCl acid was used in the wet etching process to modify its surface morphology that can be used as an anti-reflective layer of optoelectric devices. The effect of etching time on its structure, surface morphologies and optical properties were scrutinized. The overall results indicated that HCl acid has obviously effect on significant change in surface morphologies and its roughness varied in the range of 0.5 nm to 4.9 nm.

scholarly journals Preparation and Characterization of Copper, Iron, and Nickel Doped Titanium Dioxide Photocatalysts for Decolorization of Methylene Blue

2021 ◽  
Vol 50 (1) ◽  
pp. 135-149
Author(s):  
Jawed Qaderi ◽  
Che Rozid Mamat ◽  
Aishah Abdul Jalil
Keyword(s):  
Titanium Dioxide ◽  
Visible Light ◽  
Uv Light ◽  
Irradiation Time ◽  
Sol Gel ◽  
Light Response ◽  
Pure Tio2 ◽  
Necessary Condition ◽  
Doped Tio2 ◽  
Bet Analysis

The visible-light response is a necessary condition for titanium dioxide (TiO2) photocatalyst to function as a visible light active photocatalyst. This condition can be solved by investigation of the bandgaps and the optimization of doping levels of multivalency metal-doped TiO2. In this study, pure and Cu, Fe, and Ni-doped TiO2 photocatalysts were prepared by the sol‐gel method. The photocatalysts were characterized using XRD, FTIR, FESEM, EDX, N2 physisorption, and UV‐Vis spectrophotometry techniques. The XRD patterns of all pure TiO2 and Cu/TiO2, Fe/TiO2, and Ni/TiO2samples showed the dominant structure of the anatase TiO2 phase. The presence of functional groups at the interface of TiO2 particles was showed by FTIR. The FESEM analysis showed that the particle size of the prepared samples was uniform with spherical morphology. EDX results showed that TiO2 has successfully incorporated Cu, Fe, and Ni metals onto its surface. The BET analysis showed that the specific surface area of the doped samples increased with the amount of doping. The optical properties of all samples were carried out using UV-DRS measurements and their obtained bandgap energies were in the range of 3.22 - 3.42 eV. The pure TiO2 displayed more than 98% and 97% decolorization rates for MB solution at the end of irradiation time of 5 h under UV and visible light, respectively. Among the doped samples, 3 mol% Ni/TiO2 and Cu/TiO2 demonstrated the highest photocatalytic activity (97.65%) under UV light and 6 mol% Ni/TiO2 under visible light for MB (96.86%) decolorization.

scholarly journals SYNTHESIS OF Fe2O3-MONTMORILLONITE AND ITS APPLICATION AS A PHOTOCATALYST FOR DEGRADATION OF CONGO RED DYE

2010 ◽  
Vol 5 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Karna Wijaya ◽  
Iqmal Tahir ◽  
Nanik Haryanti
Keyword(s):  
Congo Red ◽  
Diffuse Reflectance ◽  
Uv Light ◽  
Band Gap Energy ◽  
Comparison Result ◽  
X Ray ◽  
Gap Energy ◽  
Congo Red Dye ◽  
Uv Illumination ◽  
Red Dye

The preparation of Fe2O3-montmorillonite and it's application as a catalyst for congo red dye photodegradation has been carried out. Fe2O3-montmorillonite was prepared by mixing the iron complexes pillaring agent and montmorillonite. The product was calcined at 250 oC for 5 hours. Montmorillonite and calcined product was analyzed by X-ray diffractometry (X-RD), infrared spectrophotometry (FTIR), gas  sorption analyser, X-ray fluorescense (X-RF) and UV/Vis diffuse reflectance spektrophotometry (UV-DRS). Fe2O3-montmorilonite then was used as a catalyst on congo red dye photodegrdation by UV-illuminating a mixture of 50 mg Fe2O3-montmorillonite and 25 mL congo red 10­-4M at 365 nm at various illuminating times. Adsorption of congo red on Fe2O3-montmorillonite and montmorillonite was also performed as a comparison. Result of X-RD analysis showed that the 001 reflection of  Fe2O3-montmorillonite was not  detected that probably indicating the formation of house of card stucture and this result was supported also by the analysis result of distribution of pores and SEM photography result. Results of the XRF analysis showed that iron content increased  from 5.21 % (w/w) in montmorillonite to 25.12 % (w/w) in Fe2O3-montmorillonite. UV- DRS analysis showed the increament of band gap energy from 3.69 eV in the iron oxide bulk to 3.8 eV in Fe2O3-montmorillonite. Specific surface area of the montmorillonite also increased significantly from 69,71 m2/g to 126,49 m2/g and total pores volume increased from 50.70x10-3 mL/Å/g  to 107.89x10-3 mL/Å/g, respectively. Photodegradation of congo red using Fe2O3-montmorillonite caused the decreament of congo red concentration up to 90.22 %  on UV illumination for 60 minutes. Adsorption of congo red on Fe2O3-montmorillonite reached 84.4% and on  montmorillonite was 75.15 %.   Keywords: photodegradation, congo red, Fe2O3-montmorillonite, UV light

SCANNING ELECTRON MICROSCOPE AND X-RAY DIFFRACTION STUDIES ON THE LATTICE CONSTANT OF SPIN-COATED Zn1-xMgxO THIN FILMS OF SOL-GEL METHOD

2005 ◽  
Vol 12 (04) ◽  
pp. 605-610 ◽  
Author(s):  
M. RUSOP ◽  
K. UMA ◽  
T. SOGA ◽  
T. JIMBO
Keyword(s):  
Thin Films ◽  
Lattice Constant ◽  
Zinc Acetate Dihydrate ◽  
Sol Gel ◽  
Zno Films ◽  
Silicon Substrates ◽  
Acetate Dihydrate ◽  
Glass Substrates ◽  
Sol Gel Process ◽  
Coating Method

ZnO and Zn 1-x Mg x O thin films were prepared on glass and silicon substrates by spin coating method using 2-methoxyethanol solution of zinc acetate dihydrate and magnesium acetate dihydrate stabilized by monoethanolamine. The effects of drying and annealing condition of structural and optical properties of the films were studied. It was found that the samples annealed at 650°C improves the crystallographic orientation of the ZnO films grown by the sol-gel process significantly. Two types of substrates were used to examine the substrate effects of the growth of Zn 1-x Mg x O thin films. In corning glass substrates, the lattice constant decreased by a little with increasing concentration of Mg , whereas in the case of silicon substrates, the lattice constant decreased rapidly with x when compared to the glass substrates. The optical band energy gaps of Zn 1-x Mg x O thin films were slightly increased with increasing concentration of Mg .

Investigate the Reliable and Accurate Pattern Transfer of IDE Silver Electrode Coated with Zinc Oxide Microwire for Biosensor Application

2014 ◽  
Vol 925 ◽  
pp. 529-532
Author(s):  
R. Haarindra Prasad ◽  
Kai Long Foo ◽  
U. Hashim
Keyword(s):  
Zinc Oxide ◽  
Electronic Device ◽  
Uv Light ◽  
Sol Gel ◽  
Electrical Characterization ◽  
Pattern Transfer ◽  
Zno Films ◽  
Oxide Material ◽  
Chemical Route ◽  
Biosensor Application

This paper illustrate a facile route to fabricate and develop zinc oxide microwire which acts as transducer for biosensor application. Pattern transfer process is conducted on the wafer substrate by using conventional photolithography process to form IDE electrode. The substrate is coated with positive photo-resist (PR) and exposed for UV light for 10 seconds. After development, the unexposed area is etched by using hydrochloric acid, HCI. In this study, zinc oxide material have become a remarkable choice for bio-sensing development due to large band gap and tailor for bio-molecular application. Zinc oxide solution was prepared through chemical route, that is by using sol-gel method. The coated ZnO films were annealed in furnace at 500°C for 2 hours. ZnO seed solution undergoes hydrothermal growth to synthesize ZnO microwires. ithThe substrate used for this study is p-type silicon wafer which is oxidized. SiO2 layer is used because it acts as an insulator which is very essential for an electronic device to avoid electrical leakage and improve electron mobility. Further investigation of morphological and electrical characterization is conducted through SEM and I-V test .Average size diameter of Zno microwire is 0.45μm and exhibit 900μA of current at 5V.

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