EFFECT OF W-DOPING ON MORPHOLOGY, STRUCTURAL AND OPTICAL PROPERTIES OF ZnO NANOSTRUCTURES SYNTHESIZED VIA THERMAL EVAPORATION

2012 ◽  
Vol 26 (27) ◽  
pp. 1250176 ◽  
Author(s):  
HOSEIN ESHGHI ◽  
YASER ARJMAND
Keyword(s):  
Room Temperature ◽  
Thermal Evaporation ◽  
Hexagonal Structure ◽  
Zno Nanostructures ◽  
Structural And Optical Properties ◽  
Thermal Evaporation Method ◽  
Violet Emission ◽  
Pl Spectra ◽  
Uv Emission ◽  
Oxygen Gas

Undoped and W -doped ZnO nanostructures were prepared by heating Zn and WO 3 powders in the presence of oxygen gas without any catalyst, using the thermal evaporation method at 950°C. Samples were characterized by FESEM images, also EDS, XRD and PL spectra. FESEM images showed the formation of nanowires in the undoped sample and porous nanostructures as flat-surface granules with various sizes in the doped samples. XRD spectra of the samples confirmed the formation of wurtzite hexagonal structure with (002) as the preferred orientation, while its intensity has reduced as the doping concentration has increased. Meanwhile, the room temperature PL spectra have indicated this variation is in conjunction with the reduction in the intensity of UV emission and appearance of a violet emission at 420 nm (2.95 eV).

Low-Temperature Growth of Flower-Shaped UV-Emitting ZnO Nanostructures on Steel Alloy by Thermal Evaporation

2007 ◽  
Vol 7 (12) ◽  
pp. 4421-4427 ◽  
Author(s):  
Ahmad Umar ◽  
S. H. Kim ◽  
J. H. Kim ◽  
Y. K. Park ◽  
Y. B. Hahn
Keyword(s):  
Thermal Evaporation ◽  
Hexagonal Phase ◽  
Zinc Powder ◽  
Hexagonal Structure ◽  
Structural Defects ◽  
Metal Catalyst ◽  
Steel Alloy ◽  
Zno Nanostructures ◽  
Uv Emission ◽  
Wurtzite Hexagonal Phase

Flower-shaped ZnO nanostructures, containing the triangular-shaped petals (sharpened tips and wider bases) have been achieved by simple thermal evaporation of high purity metallic zinc powder in the presence of oxygen at 440 °C on steel alloy substrate without the use of metal catalyst or additives. Detailed structural studies confirm that the obtained flower-shaped nanostructures are single crystalline and possesses a wurtzite hexagonal structure, grown along the c-axis in the [0001] direction. Raman and room temperature photoluminescence analysis substantiate a wurtzite hexagonal phase with a good crystal quality and a strong UV emission at 378 nm, respectively, indicating few or no structural defects. Additionally, a detailed possible growth mechanism has also been discussed.

Hierarchical ZnO Nanostructures: Growth and Optical Properties

2008 ◽  
Vol 8 (12) ◽  
pp. 6355-6360
Author(s):  
Ahmad Umar ◽  
A. Al. Hajry ◽  
S. Al-Heniti ◽  
Y.-B. Hahn
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Hexagonal Phase ◽  
Hierarchical Structures ◽  
Zinc Powder ◽  
Zno Nanostructures ◽  
Hierarchical Nanostructures ◽  
Uv Emission ◽  
Wurtzite Hexagonal Phase

Growth of hierarchical ZnO nanostructures composed of ZnO nanoneedles have been achieved via simple thermal evaporation process by using metallic zinc powder in the presence of oxygen at low temperature of 460 °C on silicon substrate without the use of any kind of metal catalysts or additives. It is confirmed by detailed structural studies that the as-grown hierarchical nanostructures are single crystalline with a wurtzite hexagonal phase and nanoneedles of these structures are grown along the c-axis in the [0001] direction. The Raman-scattering analysis substantiates a wurtzite hexagonal phase with a good crystal quality for the as-grown products. Room-temperature photoluminescence (PL) exhibits a strong UV emission at 380 nm confirming the excellent optical properties of as-synthesized hierarchical structures. A plausible growth mechanism is also proposed to clearly understand the growth process of the synthesized structures.

The effect of induced strains on photoluminescence properties of ZnO nanostructures grown by thermal evaporation method

2016 ◽  
Vol 30 (07) ◽  
pp. 1650081 ◽  
Author(s):  
Yaser Arjmand ◽  
Hosein Eshghi
Keyword(s):  
Main Parameter ◽  
Morphological Study ◽  
Thermal Evaporation ◽  
Zinc Powder ◽  
Hexagonal Structure ◽  
Optical Data ◽  
Metallic Zinc ◽  
Zno Nanostructures ◽  
Photoluminescence Properties ◽  
Thermal Evaporation Method

In this paper, ZnO nanostructures have been synthesized by thermal evaporation process using metallic zinc powder in the presence of oxygen on [Formula: see text]-Si (100) at different distances from the boat. The structural and optical characterizations have been carried out. The morphological study shows various shape nanostructures. XRD data indicate that all samples have a polycrystalline wurtzite hexagonal structure in such a way that the closer sample has a preferred orientation along (101) while the ones farther are grown along (002) direction. From the structural and optical data analysis, we found that the induced strains are the main parameter controlling the UV/green peaks ratios in the PL spectra of the studied samples.

Morphology Control and Photoluminescent Properties of Bundled ZnO Nanorods Array Based on Silicon Nanoporous Pillar Array

2017 ◽  
Vol 727 ◽  
pp. 598-603
Author(s):  
Ling Li Wang ◽  
Shi Quan Feng ◽  
Hai Yan Wang
Keyword(s):  
Room Temperature ◽  
Oxygen Vacancies ◽  
Thermal Evaporation ◽  
Growth Parameters ◽  
Zno Nanorods ◽  
Green Emission ◽  
Thermal Evaporation Method ◽  
Violet Emission ◽  
Pillar Array ◽  
Nanorods Array

A silicon nanoporous pillar array (Si-NPA) is a silicon hierarchical structure with regularly patterned surface morphology. An array of bundled ZnO nanorods was grown based on Si-NPA by a catalyst-free thermal evaporation method. The morphology of ZnO/Si-NPA was found to be greatly affected by the growth parameters such as the grown temperature and the ratio nitrogen and oxygen. The room-temperature photoluminescence (PL) spectrum of ZnO/Si-NPA showed a violet emission at ∼410 nm and a blue-green emission around 500 nm, which were attributed to the PL of Si-NPA substrate and oxygen vacancies of ZnO, respectively. The results indicated that ZnO/Si-NPA is a promising optical material.

A Review on Thermal Evaporation Method to Synthesis Zinc Oxide as Photocatalytic Material

2021 ◽  
Vol 31 ◽  
pp. 55-63
Author(s):  
Najiha Hamid ◽  
Syahida Suhaimi ◽  
Muhammad Zamir Othman ◽  
Wan Zakiah Wan Ismail
Keyword(s):  
Zinc Oxide ◽  
Vapour Deposition ◽  
Thermal Evaporation ◽  
Three Dimensional ◽  
Oxide Material ◽  
Physical Vapour Deposition ◽  
Evaporation Process ◽  
Zno Nanostructures ◽  
Thermal Evaporation Method ◽  
Photocatalytic Material

Zinc oxide (ZnO) is a metal oxide material that is interested in research due to its possibility of bandgap tailoring, doping with various types of materials as well as being able to form many structures from zero-dimensional to three-dimensional structures. All these properties allow ZnO to be used in broad applications. Several research studies have been reported on the synthesis of ZnO nanostructures by the physical vapour deposition (PVD) technique. One of the potential PVD technique is thermal evaporation process. Generally, the technique is used to grow thin-film but researchers have found a potential to be used in the growth of nanostructures due to the ability to provide high crystallinity with homogeneous and uniform nanostructures. This analysis will therefore explore more about the thermal evaporation synthesized ZnO nanostructures and the application as photocatalyst material in wastewater treatment.

PREPARATION, CHARACTERIZATION AND LUMINESCENCE PROPERTIES OF Eu DOPED CaAl2O4 NANOCONES

2013 ◽  
Vol 27 (19) ◽  
pp. 1341018 ◽  
Author(s):  
J. M. LIANG ◽  
L. L. HE ◽  
Z. Q. SHEN ◽  
D. L. ZHANG
Keyword(s):  
Electron Microscope ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
The Body ◽  
Monoclinic Structure ◽  
Thermal Evaporation Method ◽  
Room Temperature Photoluminescence ◽  
Spectrum Measurement ◽  
Transmission Electron ◽  
First Time

Europium doped CaAl 2 O 4 nanocones have been grown first time by thermal evaporation method. Scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to analyze the morphology, size and crystal structure of the nanocones. The body of the nanocones are about 2–20 μm in length and their diameters are 200 nm to 1 μm at one end and tapers off to a ~ 40–200 nm at the tip end. The as-synthesized nanocones are single crystalline in monoclinic structure and grow along the [010] direction and the normal direction of (100) and (001). The room temperature photoluminescence (PL) and cathodoluminescence (CL) spectrum measurement reveals that CaAl 2 O 4: Eu 2+ nanocones emit light at about 440 nm.

scholarly journals Compositional Dependence of Structural Properties of Prepared Alloys and Films

2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
M. F. A. Alias ◽  
A. A. J. Al-Douri ◽  
E. M. N. Al-Fawadi ◽  
A. A. Alnajjar
Keyword(s):  
Room Temperature ◽  
Thermal Evaporation ◽  
High Accuracy ◽  
Compositional Dependence ◽  
X Ray Diffraction ◽  
Thermal Evaporation Method ◽  
X Ray ◽  
Glass Substrates ◽  
Different Temperatures ◽  
Good Agreement

Results of a study of alloys and films with various Pb content have been reported and discussed. Films of of thickness 1.5 μm have been deposited on glass substrates by flash thermal evaporation method at room temperature, under vacuum at constant deposition rate. These films were annealed under vacuum around 10−6Torr at different temperatures up to 523 K. The composition of the elements in alloys was determined by standard surfaces techniques such as atomic absorption spectroscopy (AAS) and X-ray fluorescence (XRF), and the results were found of high accuracy and in very good agreement with the theoretical values. The structure for alloys and films is determined by using X-ray diffraction. This measurement reveals that the structure is polycrystalline with cubic structure and there are strong peaks at the direction (200) and (111). The effect of heat treatment on the crystalline orientation, relative intensity, and grain size of films is presented.

scholarly journals Annealing Effect on the Thermoelectric Properties of Bi2Te3Thin Films Prepared by Thermal Evaporation Method

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jyun-Min Lin ◽  
Ying-Chung Chen ◽  
Chi-Pi Lin
Keyword(s):  
Thin Films ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Thermal Evaporation Method ◽  
Si Substrates ◽  
Seebeck Coefficients

Bismuth telluride-based compounds are known to be the best thermoelectric materials within room temperature region, which exhibit potential applications in cooler or power generation. In this paper, thermal evaporation processes were adopted to fabricate the n-type Bi2Te3thin films on SiO2/Si substrates. The influence of thermal annealing on the microstructures and thermoelectric properties of Bi2Te3thin films was investigated in temperature range 100–250°C. The crystalline structures and morphologies were characterized by X-ray diffraction and field emission scanning electron microscope analyses. The Seebeck coefficients, electrical conductivity, and power factor were measured at room temperature. The experimental results showed that both the Seebeck coefficient and power factor were enhanced as the annealing temperature increased. When the annealing temperature increased to 250°C for 30 min, the Seebeck coefficient and power factor of n-type Bi2Te3-based thin films were found to be about −132.02 μV/K and 6.05 μW/cm·K2, respectively.

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