Effects of Thermal Annealing in Nitrogen on Photoluminescence of Sol-Gel Derived ZnO Nanocrystals

2013 ◽  
Vol 538 ◽  
pp. 26-29
Author(s):  
Qing Lan Ma ◽  
Bao Gai Zhai ◽  
Rui Xiong ◽  
Yuan Ming Huang
Keyword(s):  
Thermal Annealing ◽  
Annealing Temperature ◽  
Deep Level ◽  
Zinc Acetate Dihydrate ◽  
Sol Gel ◽  
Alcoholic Solution ◽  
Acetate Dihydrate ◽  
Green Color ◽  
Zno Nanocrystals ◽  
Method Effects

The synthesis of ZnO nanocrystals is carried out in alkaline alcoholic solution of zinc acetate dihydrate by sol-gel method. Effects of thermal annealing in nitrogen on photoluminescence (PL) properties of the sol-gel derived ZnO nanocrystals were investigated by PL spectroscopy. With increasing annealing temperature in nitrogen, UV emissions of the ZnO nanocrystals red-shifted from 378 nm to 388 nm while deep-level luminescent bands ranging from 450 to 700 nm with three emission centers at about 502 nm, 538 nm and 602 nm are enhanced, and the green luminescent band gains its intensity at the expense of the yellow and orange luminescent bands. Our results have demonstrated that the origin yellow-green color PL was tuned towards the cyan color PL with increasing the thermal annealing temperature in nitrogen from 344 oC to 813 oC.

scholarly journals Synthesis of 1D, 2D, and 3D ZnO Polycrystalline Nanostructures Using the Sol-Gel Method

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Yung-Kuan Tseng ◽  
Ming-Hung Chuang ◽  
Yen-Cheng Chen ◽  
Chao-Hsien Wu
Keyword(s):  
Phase Transition ◽  
Zinc Acetate Dihydrate ◽  
Sol Gel ◽  
Formation Mechanisms ◽  
Zno Nanostructures ◽  
Photocatalytic Efficiency ◽  
Acetate Dihydrate ◽  
Synthetic Process ◽  
Good Crystallinity ◽  
2D And 3D

This study employed various polyol solvents to synthesize zinc oxide polycrystalline nanostructures in the form of fibers (1D), rhombic flakes (2D), and spheres (3D). The synthetic process primarily involved the use of zinc acetate dihydrate in polyol solutions, which were used to derive precursors of zinc alkoxides. Following hydrolysis at 160°C, the zinc alkoxide particles self-assembled into polycrystalline nanostructures with different morphologies. Following calcination at 500°C for 1 h, polycrystalline ZnO with good crystallinity was obtained. FE-SEM explored variations in surface morphology; XRD was used to analyze the crystalline structures and crystallinity of the products, which were confirmed as ZnO wurtzite structures. FE-TEM verified that the ZnO nanostructures were polycrystalline. Furthermore, we employed TGA/DSC to observe the phase transition. According to the results of property analyses, we proposed models of the relevant formation mechanisms. Finally, various ZnO structures were applied in the degradation of methylene blue to compare their photocatalytic efficiency.

SPECTROSCOPIC ELLIPSOMETRY STUDIES ON ZINC OXIDE THIN FILMS DEPOSITED BY SOL–GEL METHOD WITH VARIOUS PRECURSOR CONCENTRATIONS

2019 ◽  
Vol 26 (03) ◽  
pp. 1850158 ◽  
Author(s):  
MARYAM MOTALLEBI AGHGONBAD ◽  
HASSAN SEDGHI
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Optical Properties ◽  
Spectroscopic Ellipsometry ◽  
Zinc Acetate ◽  
Optical Band Gap ◽  
Zinc Acetate Dihydrate ◽  
Sol Gel ◽  
Zno Thin Films ◽  
Acetate Dihydrate

Zinc Oxide thin films were deposited on glass substrates by sol–gel spin coating method. Zinc acetate dihydrate, 2-methoxyethanol and monoethanolamine were used as precursor, solvent and stabilizer, respectively. Zinc acetate dihydrate was used with different molar concentrations of 0.15, 0.25 and 0.5 M. Optical properties of ZnO thin films such as dielectric constants, absorption coefficient, Urbach energy and optical band gap energy were calculated by spectroscopic ellipsometry (SE) method. The effect of zinc acetate concentration on optical properties of ZnO thin films is investigated. ZnO thin film with Zn concentration of 0.25 M had the highest optical band gap. Wemple DiDomenico oscillator model was used for calculation of the energy of effective dispersion oscillator, the dispersion energy, the high frequency dielectric constant, the long wavelength refractive index and the free carrier concentration.

Effects of Annealing on Properties of (Na,Mg):ZnO Thin Films Deposited by Sol-Gel Method

2014 ◽  
Vol 898 ◽  
pp. 33-36 ◽  
Author(s):  
Cai Zhen Zhang ◽  
Yong Gang Chen ◽  
Su Liu
Keyword(s):  
Annealing Temperature ◽  
Sol Gel ◽  
Zno Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Coating Method ◽  
Method Effects ◽  
Structural Surface ◽  
Co Doped

Na/Mg co-doped (Na,Mg):ZnO films were fabricated on pyrex glass substrates by sol-gel spin-coating method. Effects of annealing on properties of the films were particularly investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmittance spectra. The internal stress of the films annealed at different temperature was calculated. Experimental and analytical results show that some NaCl freeze-out derivatives will appear on films when the annealing temperature is too low, with the increasing annealing temperature, the c-axis tensile stress is sharply decreased first, then the c-axis stress was changed into press stress and its value is increased continuously, so the structural, surface and the optical properties of the films improve first and deteriorate afterwards.

Influence of Thermal Annealing on the Properties of Sol-Gel-Derived Al:ZnO Thin Films

2015 ◽  
Vol 1109 ◽  
pp. 186-190
Author(s):  
Mohd Firdaus Malek ◽  
Mohamad Hafiz Mamat ◽  
M.Z. Musa ◽  
M. Rusop
Keyword(s):  
Thin Films ◽  
Thermal Annealing ◽  
Annealing Temperature ◽  
Film Growth ◽  
Sol Gel ◽  
Visible Region ◽  
Dip Coating ◽  
Granular Structure ◽  
Annealing Temperatures ◽  
Average Transmittance

Aluminium doped zinc oxide (Al:ZnO) thin films were prepared by a sol-gel dip coating process. In particular, the case of change of thermal annealing temperature was studied. The characterisation of the films by various analytical methods shows a correlation between thermal annealing temperature and characteristic of the film. The influence of the thermal annealing temperature on the film growth can be clearly observed. At lower thermal annealing temperatures, granular structure dominates the films, while the films feature a bigger grain growth at higher annealing temperatures. All films exhibited an average transmittance of greater than 85% in the visible region, with absorption edges at ~380 nm.

scholarly journals Sintesis Mg2+ doped ZnO dengan penambahan albumen ayam ras menggunakan gabungan metode sol-gel dan sonokimia

2021 ◽  
Vol 12 (1) ◽  
pp. 27-35
Author(s):  
Sherly Kasuma Warda Ningsih ◽  
Umar Kalmar Nizar ◽  
Bahrizal Bahrizal ◽  
Edi Nasra ◽  
Siti Fatimah Mutiara R
Keyword(s):  
Crystal Structure ◽  
Surface Morphology ◽  
Crystal Size ◽  
Zinc Acetate Dihydrate ◽  
Sol Gel ◽  
Ftir Analysis ◽  
Acetate Dihydrate ◽  
Chloride Hexahydrate ◽  
Doped Zno ◽  
Absorbance Band

Mg2+ doped ZnO has been successfully synthesized using a combination of sol-gel and sonochemical methods. Zinc acetate dihydrate was used as a precursor, magnesium chloride hexahydrate as a source of Mg dopant, methanol as a solvent, and chicken albumen was used as an additive to replace monoethanolamine. The sol was heated at 110 °C for 1 hour. The gel formed was calcined at 600 °C for 3 hours. FTIR analysis shows that the absorbance band around 400-450 cm-1 indicates Mg-O stretching, the absorbance band around 500-550 cm-1 indicates Zn-O stretching, the absorbance band around 400-550 cm-1 shows Zn-O-Mg bonds. Mg. Measurements with UV-DRS, obtained the smallest ZnO band gap value doped Mg2+ around 2.7 eV with the addition of 10 mL albumen. The resulting crystal structure was wurtzite with crystal size with the addition of 10, 20, 30, 40 and 50 mL albumen were 25.22-55.91 nm, 32.99-75.87 nm, 45.92-83.91 nm, 45.92-75.89 nm and 46.15-71.47 nm respectively. SEM photo of Mg2+ doped ZnO with the addition of 10 mL of albumen has a hexagonal surface morphology.

Thermal Annealing-Activated Crystallinity Metastasis of Al:ZnO Thin Films

2015 ◽  
Vol 1109 ◽  
pp. 181-185 ◽  
Author(s):  
Mohd Firdaus Malek ◽  
Mohamad Hafiz Mamat ◽  
M.Z. Musa ◽  
M. Rusop
Keyword(s):  
Thin Films ◽  
Thermal Annealing ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Dip Coating ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dip Coating Technique ◽  
Multilayered Thin Films

Multilayered thin films of aluminum-doped ZnO (Al:ZnO) have been deposited by the sol-gel dip coating technique. Experimental results indicated that the thermal annealing temperature affected the crystallinity of the Al:ZnO films. X-ray diffraction (XRD) analysis showed that thin films were preferentially orientated along the c-axis plane. The preferred orientation along (0 0 2) plane becomes more pronounced as the thermal annealing being increased. The film thickness ranges between 180 and 690 nm. In our experiments, the most optimum condition of Al:ZnO annealing temperature was both 500 oC.

Improvement of Ferroelectric and Electrical Properties of Sol-Gel deposited Bi4Ti3Oi2 Thin Films by Multiple Rapid Thermal Annealing Techniques

2004 ◽  
Vol 830 ◽  
Author(s):  
Hua. Wang ◽  
Minfang Ren
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Electrical Properties ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Annealing Temperature Increase ◽  
Si Substrates ◽  
Surface Increase

AbstractFerroelectric Bi4Ti3O12 thin films were fabricated by sol-gel method with multiple rapid thermal annealing (MRTA) techniques on Pt/Ti/SiO2/p-Si substrates. The effect of annealing temperature on crystallinity, ferroelectric and electrical properties of Bi4Ti3O12 films derived by MRTA and by normal RTA were investigated. The results reveal that the grain size and the roughness of surface increase with the annealing temperature increase, but the maximal remnant polarization of Bi4Ti3O12

scholarly journals Air bubble promoted large scale synthesis of luminescent ZnO nanoparticles

2015 ◽  
Vol 3 (48) ◽  
pp. 12430-12435 ◽  
Author(s):  
S. Koch ◽  
S. Späth ◽  
A. Shmeliov ◽  
V. Nicolosi ◽  
K. Mandel
Keyword(s):  
Zinc Oxide Nanoparticles ◽  
Potassium Hydroxide ◽  
Large Scale ◽  
Zinc Acetate Dihydrate ◽  
Sol Gel ◽  
Acetate Dihydrate ◽  
One Pot ◽  
Synthesis Of Nanoparticles ◽  
Air Bubble ◽  
Sol Gel Synthesis

Luminescent zinc oxide nanoparticles were synthesized via a facile one-pot sol–gel synthesis route using zinc acetate dihydrate and potassium hydroxide as cheap precursors. It is demonstrated that dissolved oxygen plays a key role in the synthesis of nanoparticles.

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 .

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