scholarly journals Preparation of Glass Plate-Supported Nanostructure ZnO Thin Film Deposited by Sol-Gel Spin-Coating Technique and Its Photocatalytic Degradation to Monoazo Textile Dye

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Mohammad Hossein Habibi ◽  
Mohammad Khaledi Sardashti

Glass plate-supported nanostructure ZnO thin films were deposited by sol-gel spin coating. Films were preheated at275∘Cfor 10 minutes and annealed at 350, 450, and550∘Cfor 80 minutes. The ZnO thin films were transparent ca 80–90% in visible range and revealed that absorption edges at about 370 nm. Thec-axis orientation improves and the grain size increases which was indicated by an increase in intensity of the (002) peak at34.4∘in XRD corresponding to the hexagonal ZnO crystal. The photocatalytic degradation of X6G an anionic monoazo dye, in aqueous solutions, was investigated and the effects of some operational parameters such as the number of layer and reusability of ZnO nanostructure thin film were examined. The results showed that the five-layer coated glass surfaces have a very high photocatalytic performance.

2014 ◽  
Vol 971-973 ◽  
pp. 89-92
Author(s):  
Zong Hu Xiao ◽  
Yong Ping Luo ◽  
Shun Jian Xu ◽  
Wei Zhong ◽  
Hui Ou ◽  
...  

Zinc oxide (ZnO) thin films were prepared by sol-gel spin coating technique, which were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), NKD thin film analysis system and fluorescence spectrophotometer. The results show that ZnO thin films with the each layer thickness of 80 nm present obvious c-axis orientation. With the increase of coating layers, the c-axis orientation characteristic weakens. The reason is considered that the growth mode of ZnO thin films transforms from layer growth to island growth. For the ZnO thin film with 4 layers, it has a compact surface and a uniform particle size of approximately 50 nm, and the photoluminescence (PL) spectrum primarily consists of two PL emission bands, one is a strong and narrow ultraviolet (UV) emission band, another is a weak and broad luminescence emission band from 400 nm to 650 nm. The average transmittance in the visible range is beyond 90%. A optical band gap of 3.26 eV, slightly less than the intrinsic band gap width of 3.37 eV, is obtained by Tauc plotting method. The defects, such as Zn or O vacancies, grain boundaries, are considered to be the main factors causing this situation.


2021 ◽  
Author(s):  
Ştefan Ţălu ◽  
Samah Boudour ◽  
Idris Bouchama ◽  
Bandar Astinchap ◽  
Hamta Ghanbaripour

Abstract A multifractal analysis has been performed on the three-dimensional surface microtexture of the ZnO thin films doped with Mg deposited by sol-gel spin coating on glass substrates. The effects of Mg doping element with amounts of 0, 2, 4, and 5 % on structural and morphological properties of the coated films were investigated. From the X-ray diffraction pattern analysis, it was found that the obtained thin films had a polycrystalline hexagonal wurtzite structure with preferential c-axis orientation and increased grain size with increasing the Mg doping. From scanning electron microscopy (SEM) analysis, it can be concluded that the surface of coated thin films had dense and uniformly distributed grains of nanoscale without any cracks over all surfaces of coated firms. From atomic force microscope (AFM) analysis, it can be also concluded that the surface of coated thin films had a dense columnar grain growth uniformly distributed over the entire 1 µm ⋅ 1 µm - scanned area. The surface microtexture was characterized in terms of multifractal analysis.


2013 ◽  
Vol 701 ◽  
pp. 167-171 ◽  
Author(s):  
Kevin Alvin Eswar ◽  
Azlinda Ab Azlinda ◽  
F.S. Husairi ◽  
M. Rusop ◽  
Saifollah Abdullah

Zinc acetate dehydrate as starting material along with diethanolamine as stabilizer, and isopropyl as a solvent were used to synthesis ZnO thin films in different low molarities. Sol-gel spin coating method was used in depositing ZnO on porous silicon substrate surface. In other to prepare substrate, p-type silicon wafer was etched by dilute hydrofluoric acid to modify the surface becomes porous. Field Emission Scanning Electron Microscopy (FESEM) was employed to study the surface morphology. It is found that ZnO thin films were successfully deposited on the substrates which are composed of ZnO nanoparticles with size ~16 nm to ~22nm. Atomic Force Microscopy (AFM) was used to investigate the surface roughness of thin film. The result shows that the surface roughness is increase as the increases of molarities. Photoluminescence (PL) spectra were done in range of 350 nm to 800 nm. The result shows peaks belonging to ZnO, ZnO defects, and porous silicon respectively are appeared.


2013 ◽  
Vol 667 ◽  
pp. 24-29
Author(s):  
Mohamad Hafiz Mamat ◽  
A.A.A. Halim ◽  
Mohd Zainizan Sahdan ◽  
S. Amizam ◽  
Zuraida Khusaimi ◽  
...  

The effect of annealing temperatures on the Zinc Oxide (ZnO) thin films properties has been investigated. 1.0 M ZnO solution was prepared by sol-gel method as coating solution for ZnO thin films deposition process. The thin films deposition was conducted by spin-coating technique on the silicon and glass substrates. The scanning electron microscopy (SEM) images reveal the evolution of ZnO surface morphology with annealing temperatures. The crystallinity improvement occurred at higher annealing temperature as shown by x-ray diffraction (XRD) result. The optical properties found to be varied at different annealing temperatures. The current-voltage (I-V) measurement results suggested the improvement of ZnO thin film electrical properties with annealing temperatures.


2012 ◽  
Vol 19 (05) ◽  
pp. 1250055 ◽  
Author(s):  
M. SALEEM ◽  
L. FANG ◽  
Q. L. HUANG ◽  
D. C. LI ◽  
F. WU ◽  
...  

Highly transparent ZnO thin films were deposited on glass substrates by using a simple and inexpensive multi-step sol–gel spin coating process. This research investigated the effects of annealing temperature in the range from 350–600°C on the microstructure, surface morphology and optical properties of thin films by using XRD, SEM and transmittance spectra. The XRD results showed that the c-axis orientation of ZnO thin films was improved with the increase of annealing temperature. The grain size increases from 16.6–19.7 nm with the increase in temperature. The transmittance spectra indicated that the transmittance and direct optical band gap Eg of the films showed a decreased trend with annealing temperature. It is found that the tensile stress exist in the films, which decreases with the increase in annealing temperature up to 500°C, on further increasing the annealing temperature up to 600°C, the stress in the film changes from tensile to compressive nature.


2006 ◽  
Vol 957 ◽  
Author(s):  
Lee Huat Kelly Koh ◽  
Shane O'Brien ◽  
Pierre Lovera ◽  
Gareth Redmond ◽  
Gabriel M Crean

ABSTRACTZnO thin films were prepared on borosilicate glass from both single- and multi- step coating deposition of a sol-gel prepared with anhydrous zinc acetate [Zn(C2H3O2)2], monoethanolamine [H2NC2H4OH ] and isopropanol. ZnO films prepared over a range of zinc acetate concentrations, for a fixed annealing temperature, showed that sol-gels prepared with a 0.3M zinc acetate concentration resulted in the formation of films with the greatest degree of c-axis orientation. In this study, a detailed investigation of the influence of process annealing temperature over the range 450 – 550°C on the microstructural, physical, electronic and optical properties of these single and multi-step ZnO thin films around this 0.3M zinc concentration set point is presented. X-ray analysis showed that all single-step deposition thin films were preferentially orientated along the [002] c-axis direction of the crystal. In contrast, only the multi-layer film annealed at 550°C showed similar preferential orientation. All single step deposited films showed a similar average optical transmittance above 87%, independent of annealing temperature. The transmittance of the multi-step films was shown to be strongly correlated to the degree of c-axis orientation. The optical band-gap energy was evaluated to be 3.298 – 3.316 eV for all samples. The photoluminescence spectra of the single layer ZnO films showed a strong emission centred at ca. 405 nm, which blue shifted with increasing annealing temperature. The multi-layer ZnO samples emitted throughout the UV and the visible range, with the samples prepared at 500 and 550°C showing the expected ZnO emission peak at 380 nm. Despite being thicker, the emission from the multi- layer samples was less than measured for the single layer samples. The effect of sol-gel annealing temperature and deposition process on film microstructure, morphology, electrical resistivity and optical transparency is detailed.


2010 ◽  
Vol 93-94 ◽  
pp. 231-234
Author(s):  
B. Hongthong ◽  
Satreerat K. Hodak ◽  
Sukkaneste Tungasmita

Strontium substituted hydroxyapatite(SrHAp) were fabricated both in the form of powder as reference and thin film by using inorganic precursor reaction. The sol-gel process has been used for the deposition of SrHAp layer on stainless steal 316L substrate by spin coating technique, after that the films were annealed in air at various temperatures. The chemical composition of SrHAp is represented (SrxCa1-x)5(PO4)3OH, where x is equal to 0, 0.5 and 1.0. Investigations of the phase structure of SrHAp were carried out by using X-ray diffraction technique (XRD). The results showed that strontium is incorporated into hydroxyapatite where its substitution for calcium increases in the lattice parameters, and Sr3(PO4)2 can be detected at 900°C. The SEM micrographs showed that SrHAp films exhibited porous structure before develop to a cross-linking structure.


2011 ◽  
Vol 25 (20) ◽  
pp. 2741-2749 ◽  
Author(s):  
J. C. ZHOU ◽  
L. LI ◽  
L. Y. RONG ◽  
B. X. ZHAO ◽  
Y. M. CHEN ◽  
...  

High transparency and conductivity of transparent conducting oxide thin film are very important for improving the efficiency of solar cells. ZnO thin film is a better candidate for transparent conductive layer of solar cell. N-type ZnO thin films were prepared by radio-frequency magnetron sputtering on glass substrates. ZnO thin films underwent annealing treatment after deposition. The influence of the sputtering power on the surface morphology, the electrical and optical properties were studied by AFM, XRD, UV2450 and HMS-3000. The experimental results indicate that the crystal quality of ZnO thin film is improved and all films show higher c-axis orientation with increasing sputtering power from 50 to 125 W. The average transparency of ZnO thin films is higher than 90% in the range of 400–900 nm between the sputtering power of 50–100 W. After the rapid thermal annealing at 550°C for 300 s under N2 ambient, the minimum resistivity reach to 10-2Ω⋅ cm .


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