Wet Oxidation: A Promising Way for Fabrication of Zinc Oxide Nanostructures

2006 ◽  
Vol 522-523 ◽  
pp. 277-284 ◽  
Author(s):  
Wei Gao ◽  
Zheng Wei Li
Keyword(s):  
Zinc Oxide ◽  
Ultra Violet ◽  
Zno Films ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Zinc Oxide Nanostructures ◽  
Violet Emission ◽  
Red Color ◽  
Controllable Growth ◽  
Porous Oxide

A two-step deposition-oxidation method was successfully developed to fabricate zinc oxide thin films and nanostructures. Morphological observations clearly showed that a controllable growth of dense/porous oxide films, nanowhiskers, nanowires, and nanobelts could be obtained by controlling the deposition and oxidation conditions. Photoluminescence properties of the ZnO films were also studied. A strong and predominant ultra-violet near-band-edge emission could be observed on most of the samples, while a green or red color emission accompanying with a largely suppressed ultra-violet emission could be realized on the samples with different processing conditions. The results therefore indicated that ZnO films and structures with desirable microstructural and optical properties could be obtained with this deposition-oxidation technique under controllable conditions.

scholarly journals Elongated Wire-Like Zinc Oxide Nanostructures Synthesized from Metallic Zinc

2012 ◽  
Vol 15 (1) ◽  
pp. 19 ◽  
Author(s):  
El-Shazly M. Duraia ◽  
G.W. Beall ◽  
Zulkhair A. Mansurov ◽  
Tatyana A. Shabanova ◽  
Ahmed E. Hannora
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Silicon Substrate ◽  
Gas Flow ◽  
Flow Direction ◽  
Crystal Defects ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Metallic Zinc ◽  
Zinc Oxide Nanostructures

Elongated wire-like Zinc oxide, nanocombs and nanocrystals have been successfully synthesized on the silicon substrate from the metallic zinc as a starting material. The annealing temperature was as low as 450 ºC in argon atmosphere mixed with about 3% oxygen. Structural analysis using the X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) showed that the existence of two phases; nanowires and crystalline form. Moreover some nanoparticles aggregates were noticed to be attached in the bulk to the sides of the ZnO nanocrystals and sometimes these aggregate attached to the Zinc oxide hexagonal crystal and grow to form nanowire at different angles. Scanning electron microscopy (SEM) investigations for the zinc oxide nanostructure on the silicon substrate showed the formation of the nanocrystals in the gas flow direction and at the low energy sites over the silicon substrate. Photoluminescence (PL) measurements, performed at the room temperature, showed the existence of two basic emissions: narrow ultraviolet (UV) emission at 398 nm which attributed to the near band edge emission of the wide band gap and a very wide, more intensive, green emission at 471 nm corresponds to the crystal defects such as vacancies, interstitial sites in ZnO.

scholarly journals Effect of Sintering Temperature on the Characteristics of Zn0.99Li0.01O Thin Film on Si Substrate

2020 ◽  
Vol 58 (4) ◽  
pp. 257-262
Author(s):  
Gang Bae Kim ◽  
June Won Hyun
Keyword(s):  
Zinc Oxide ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Stable Solution ◽  
Ultra Violet ◽  
Green Emission ◽  
Red Shift ◽  
Crystal Phase ◽  
Zno Films ◽  
Violet Emission

Lithium-doped zinc oxide (Zn0.99Li0.01O) film was manufactured by the sol-gel method using uniform and stable solution of zinc acetate dehydrate and lithium acetate dehydrate in methanol. Films were deposited by spin-coating using spinner between 4500 and 5000 rpm on silicon substrates. The prepared samples were sintered at various temperatures (600 oC ~ 1000 oC) in the air. The structural, morphological, and optical properties of the prepared lithium-doped ZnO films were investigated. The XRD pattern of Zn0.99Li0.01O film demonstrated the hexagonal wurzite structure. However, new crystal phase was discovered at a sintering temperature of 800 oC. New peak was found near 2θ = 22.6o in XRD patterns. The peak is thought to be the (101) plan in SiO2 cristobalite structure. Moreover, another new crystal phase related to Li2SiO5 was occurred at a sintering temperature of 900 oC. From XRD analysis, it was confirmed that C axis was decreased and the stress was increased, as sintering temperatures was increased from 600 oC to 900 oC. In cathodo luminescence (CL) data, zinc oxide usually appears ultra violet and green emission. However, the green emission did not appear in all these samples used in this study. The ultra violet emission showed red shift from 600 oC to 800 oC in the CL spectrum as the sintering temperature was increased. The phenomenon of the red shift can be explained in Burstein-Moss effect. At sintering temperature of 700 oC, the intensity of ultra-violet emission was the largest and full width at half maximum (FWHM) was the smallest.

Growth Spindle-Like ZnO Nanocrystalline Thin Films on Nickel Layers by Dc Magnetron Sputtering and its Thermal Annealing Properties

2011 ◽  
Vol 675-677 ◽  
pp. 1097-1100
Author(s):  
W. Wu ◽  
X.H. Xiao ◽  
T.C. Peng ◽  
C.Z. Jiang
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Structural Features ◽  
Optical Quality ◽  
Zno Films ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Dc Magnetron Sputtering ◽  
Band Emission ◽  
Thin Film Layer

A novel spindle-like zinc oxide (ZnO) nanocrystalline thin film was successfully fabricated on Ni thin film layer by ultrahigh-vacuum dc magnetron sputtering. Then the as-grown films were annealed in air at various temperatures from 673 to 1073 K, the corresponding structural features and surface morphology were studied by X-ray diffraction (XRD) and field emission scanning electronic microscopy (FE-SEM). The results reveal that the dominant direction of grains movement changed from perpendicular to parallel to the film interfaces. A correlation of the band gap and photoluminescence (PL) properties of nanocrystalline ZnO films with particle size morphologies and strain was discussed. Especially, PL emission in UV range, which is due to near band edge emission is more intense in comparison with the green band emission (due to defect state) was observed in all samples, indicating a good optical quality of the deposited films.

Zinc Oxide Nanostructures Doped with Transition Metals: Fabrication and Properties

2019 ◽  
Vol 18 (03n04) ◽  
pp. 1940045 ◽  
Author(s):  
E. Chubenko ◽  
I. Gerasimenko ◽  
V. Bondarenko ◽  
D. Zhigulin
Keyword(s):  
Zinc Oxide ◽  
Transition Metals ◽  
Hydrothermal Method ◽  
Zno Films ◽  
Ferromagnetic Behavior ◽  
Silicon Substrates ◽  
Zinc Oxide Nanostructures ◽  
Sem Images ◽  
Nanostructured Films ◽  
Oxide Nanostructures

ZnO nanostructured films doped with Co and Ni deposited by hydrothermal method on silicon substrates covered with undoped ZnO sublayer were studied. SEM images of the films demonstrated them to consist of densely packed vertical nanopillars. Doping ZnO films with Ni or Co at concentrations up to [Formula: see text][Formula: see text]cm[Formula: see text] quenches their UV-excited photoluminescence. The doping also leads to the slight ferromagnetic behavior of ZnO.

Photoluminescence of ZnO Nanocrystals Embedded in BaF2 Matrices by Magnetron Sputtering

2008 ◽  
Vol 8 (3) ◽  
pp. 1160-1164
Author(s):  
C. H. Zang ◽  
Y. C. Liu ◽  
R. Mu ◽  
D. X. Zhao ◽  
J. Y. Zhang ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Raman Scattering ◽  
Free Exciton ◽  
Wide Band ◽  
Zno Films ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Ultraviolet Emission ◽  
Pl Spectra ◽  
Zno Nanocrystals

This paper describes ZnO nanocrystals embedded in BaF2 matrices by the magnetron sputtering method in an attempt to use fluoride as a shell layer to embed ZnO nanocrystals core. BaF2 is a wide-band gap material, and can confine carriers in the ZnO films. As a result, the exciton emission intensity should be enhanced. The sample was annealed at 773 K, and X-ray diffraction (XRD) results showed that ZnO nanocrystals with wurtzite structure were embedded in BaF2 matrices. Raman-scattering spectra also confirmed the formation of ZnO nanoparticles. Abnormal longitudinal-optical (LO) phonon-dominant multiphonon Raman scattering was observed in the sample. Room-temperature photoluminescence (PL) spectra showed an ultraviolet emission peak at 374 nm. The origin of the ultraviolet emission is discussed here with the help of temperature-dependent PL spectra. The ultraviolet emission band was a mixture of free exciton and bound exciton recombination observed in the low temperature PL spectra (at 77 K). Abnormal temperature dependence of ultraviolet near-band-edge emission-integrated intensity of the sample was observed. The band tail state was observed in the absorption spectra, illustrating that the impurity-related defects were caused by the shell of the BaF2 grain layer. For comparison, ZnO films on BaF2 substrates were also fabricated by the magnetron sputtering method, and the same measurement methods were used.

Effect of Annealing Temperature on the Optical and Structural Properties of Ge Doped ZnO Films

2011 ◽  
Vol 304 ◽  
pp. 79-83
Author(s):  
Dong Hua Fan ◽  
Kai Zhen Huang ◽  
Yu Bao Huang
Keyword(s):  
Structural Properties ◽  
Photoelectron Spectroscopy ◽  
Annealing Temperature ◽  
Free Exciton ◽  
Ultra Violet ◽  
Zno Films ◽  
Violet Emission ◽  
X Ray ◽  
High Annealing ◽  
Doped Zno

Ge doped ZnO films were synthesized on silicon substrate via RF magnetron co-sputtering methods. The effects of annealing temperature on the optical and structural properties of the Ge doped ZnO films were investigated by means of photoluminescence spectra, X-ray diffraction, and X-ray Photoelectron Spectroscopy. The ultra-violet emission should be related with the free-exciton recombination, and blue and yellow emissions should be attributed to the defect state caused by Ge. The varieties of annealing temperature affect greatly the optical properties. The high annealing temperature leads to the oxidation of Ge and the formation of Zn2GeO4, which could lead to the change of PL spectra.

Ultra-Fine ZnO Nanobelts and their Photoluminescence Emission

2005 ◽  
Vol 872 ◽  
Author(s):  
Aurangzeb Khan ◽  
Martin E Kordesch
Keyword(s):  
Electrical Properties ◽  
Thermal Evaporation ◽  
Ultra Violet ◽  
Blue Shift ◽  
Near Band Edge ◽  
Optical And Electrical Properties ◽  
Photoluminescence Spectra ◽  
Average Width ◽  
Violet Emission ◽  
Evaporation And Condensation

AbstractUltra-Fine ZnO nanobelts are grown via thermal evaporation and condensation method without the use of any catalyst on the substrates. These nanobelts have an average width of about 5.8 nm. Photoluminescence spectra reveal that there is a blue shift in the near band edge ultra violet emission from 381 nm to 367 nm equal to 124 meV. These ultra-fine nanobelts have been studied for size induced optical and electrical properties.

Optical anisotropy of near band-edge transitions in zinc oxide nanostructures

2009 ◽  
Vol 480 (1) ◽  
pp. 50-53 ◽  
Author(s):  
Ching-Hwa Ho ◽  
Jian-Shen Li ◽  
Yi-Jia Chen ◽  
Ching-Cherng Wu ◽  
Ying-Sheng Huang ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Optical Anisotropy ◽  
Band Edge ◽  
Near Band Edge ◽  
Zinc Oxide Nanostructures ◽  
Oxide Nanostructures
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