Influence of TiO2 content on microstructures and optoelectronic properties of titanium-doped ZnO nanofilms

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744069
Author(s):  
Zhenying Chen ◽  
Xiaowei Chen ◽  
Fei Li ◽  
Shoulei Xu ◽  
Wenhua Huang ◽  
...  

Thin films of TiO2-doped ZnO (TZO) with TiO2 contents from 0.5 to 3.0 wt.% were deposited on glass substrates by RF magnetron sputtering. The microstructures and optoelectronic properties of the TZO films were characterized by XRD, Hall effect analyzer, UV–VIS spectrophotometry and physical property measurement (PPMS-9). Results indicate that the microstructure and optoelectronic properties of TZO films are strongly affected by the TiO2 content. The best optoelectronic properties were obtained with the film having 2.0 wt.% TiO2. This film had superior crystal properties, high average optical transmittance (89.0%), and the lowest resistivity (9.58 × 10[Formula: see text] [Formula: see text] ⋅ cm). Furthermore, the resistivity of this film changed with temperature between 10 and 350 K, they experienced an initial decrease followed by an increase as the temperature increased.

2014 ◽  
Vol 21 (01) ◽  
pp. 1450003 ◽  
Author(s):  
YUEHUI HU ◽  
YICHUAN CHEN ◽  
XIAOHUA ZHANG ◽  
DEFU MA ◽  
JUNXIANG WANG ◽  
...  

Li - W co-doped ZnO (LWZO) thin films were deposited on quartz glass substrates by RF magnetron sputtering technology. The properties of LWZO films deposited with varied substrate temperatures were investigated. When the substrate temperature was lower than 120°C — according to X-ray diffraction (XRD) patterns, films keep hexagonal wurtzite structure with the (002) plane as preferred orientation — the optical transmittance was higher than 85%. When the substrate temperature was higher than 120°C, the results of XPS and XRD show that W 6+ will work as donors, and the (101) peak appeared; the optical transmittance decreased slightly but still higher than 82%. Scanning electron microscope (SEM) and its two-dimensional Fourier transform images showed that films had smooth surface and columnar particles structure when the substrate temperature was lower than 120°C. The film surface became rougher and flaky-shaped particles structure could be observed when the substrate temperature was higher than 120°C. In addition, the lowest electrical resistivity of sample was 3.6 × 10-3 Ω ⋅ cm which was obtained at substrate temperature 240°C.


2012 ◽  
Vol 502 ◽  
pp. 72-76 ◽  
Author(s):  
Zhi You Zhong ◽  
J. Zhou ◽  
J.H. Gu ◽  
X. He ◽  
J. Hou ◽  
...  

Al-doped ZnO (ZnO:Al) thin films were deposited on glass substrates by rf magnetron sputtering technique. The effect of discharge power on the structural, optical and electrical characteristics of ZnO:Al films was investigated by X-ray diffraction (XRD), four-probe meter and optical transmission spectroscopy. The results show that the films are polycrystalline with a hexagonal wurtzite structure and preferentially oriented in the (002) crystallographic direction. The highest figure of merit of 5.58×10-3 -1 is obtained from the film prepared at the discharge power of 200 W. The average optical transmittance in the visible range of the films is over 78.2%.


2013 ◽  
Vol 275-277 ◽  
pp. 1964-1967 ◽  
Author(s):  
T. Zhang ◽  
Z.Y. Zhong ◽  
J. Zhou ◽  
F.L. Sun

TiO2-doped ZnO thin films with highly (002)-preferred orientation were grown on glass substrates by RF magnetron sputtering. The effect of substrate temperature on structure and optical properties of the films were investigated by X-ray diffractometer and spectrophotometer. The results show that the polycrystalline TiO2-doped ZnO films consist of the hexagonal crystal structures with c-axis as the preferred growth orientation normal to the substrate. The substrate temperature significantly affects the crystallite size and optical transmittance of the deposited films, but slightly influences the refractive index and optical bandgap of the deposited films. The TiO2-doped ZnO film grown at substrate temperature of 470 K possesses the maximum crystallite size, an average transmittance of 76.2 % in the visible light range, and an optical bandgap of 3.46 eV.


2011 ◽  
Vol 194-196 ◽  
pp. 2305-2311
Author(s):  
Ying Ge Yang ◽  
Dong Mei Zeng ◽  
Hai Zhou ◽  
Wen Ran Feng ◽  
Shan Lu ◽  
...  

In this study high quality of Al doped ZnO (ZAO) thin films were prepared by RF magnetron sputtering on glass substrates at room temperature in order to study the thickness effect upon their structure, electrical and optical properties. XRD results show that the films are polycrystalline and with strongly preferred (002) orientation perpendicular to substrate surface whatever the thickness is. The crystallite size was calculated by Williamson-Hall method, while it increases as the film thickness increased. The lattice stress is mainly caused by the growth process. Hall measurements revealed electrical parameter very dependent upon thickness when the thickness of ZAO film is lower than 700 nm. The resistivity decreased and the carrier concentration and Hall mobility increases as the film thickness increased. When film thickness becomes larger, only a little change in the above properties was observed. All the films have high transmittance above 90% in visible range. Red shift of the absorption edge was observed as thickness increased. The optical energy bandgap decreased from 3.41eV to 3.30 eV with the increase of film thickness.


2003 ◽  
Vol 763 ◽  
Author(s):  
K. Matsubara ◽  
H. Tampo ◽  
A. Yamada ◽  
P. Fons ◽  
K. Iwata ◽  
...  

AbstractLow resistivity and transparent Al doped ZnMgO films were deposited on glass substrates by a pulsed laser deposition system. For up to 32 atm% of Mg content, segregation of a MgO phase was not observed. The bandgap of these films could be widened to about 4 eV with increasing Mg content. The relation between bandgap and resistivity was found to be a trade-off; i.e. the larger the bandgap, the higher the resistivity. The maximum bandgap among films with an electrical resistivity of less than 10-3 Ω cm was 3.94 eV. The average optical transmittance of these films was more than 90 % for wavelengths λ between 400 and 1100 nm. The transmittance around λ = 330 nm was still 50 %.


2003 ◽  
Vol 769 ◽  
Author(s):  
E. Fortunato ◽  
A. Gonçalves ◽  
A. Marques ◽  
V. Assunção ◽  
I. Ferreira ◽  
...  

AbstractHighly transparent and conductive ZnO:Ga thin films were produced by rf magnetron sputtering at room temperature on polyethylene naphthalate substrates. The films present a good electrical and optical stability, surface uniformity and a very good adhesion to the polymeric substrates. The lowest resistivity obtained was 5×10-4 Ωcm with a sheet resistance of 15 Ω/sqr and an average optical transmittance in the visible part of the spectra of 80 %. It was also shown that by passivating the polymeric surface with a thin SiO2 layer, the electrical and structural properties of the films are improved nearly by a factor of 2.


2021 ◽  
Author(s):  
Bilel Khalfallah ◽  
I. Riahi ◽  
F. Chaabouni

Abstract RF sputtered undoped and Cu doped ZnO (CZO) thin films were deposited on unheated glass substrates using a mixed Cu2O and ZnO powders target at different Cu concentrations of 0, 1, 2, 3 and 4 wt.%. The effects of copper concentration on the structural, electrical, optical and photocatalytic properties of CZO films have been studied. From XRD and Raman spectroscopy studies, it was found that the deposited films were polycrystalline with a predominant hexagonal wurtzite structure along the c-axis perpendicular to the substrate surface. The presence of multiple interference fringes in the transmittance and reflectance spectra shows the good homogeneity of the films. All the films are highly transparent with transparency reaching 80% indicating the possibility to use these films as an optical window. The absorption tail gradually shifted towards a higher wavelength side, which resulted in the decrease of bandgap energy from 3.35 to 3.26 eV. All the sputtered films are highly conductive with a conductivity reaching 104 S.cm− 1.The effect of Cu-doping on the photocatalytic activity of ZnO thin films for the degradation of methylene blue (MB) dye was studied under sunlight irradiation and the results showed that the Cudoping provokes appreciable degradation of MB and reached a maximum for the 1 wt.% Cu doped ZnO film.


2010 ◽  
Vol 24 (32) ◽  
pp. 3089-3095 ◽  
Author(s):  
J. Y. HUANG ◽  
G. H. FAN ◽  
T. MEI ◽  
S. W. ZHENG ◽  
Q. L. NIU ◽  
...  

Tantalum-doped indium tin oxide ( Ta -doped ITO) transparent conductive films are deposited on glass substrates by electron-beam evaporation. The effects of different Ta concentrations and annealing temperatures on the structural, morphologic, electrical, and optical properties of Ta -doped ITO films are investigated by X-ray diffraction (XRD), atomic force microscope (AFM), Hall measurement, and optical transmission spectroscopy. The obtained films are polycrystalline with a cubic bixbyite structure of indium oxide and preferentially oriented in the (222) crystallographic direction. The minimum resistivity of 1.54×10-4 Ω ·cm is obtained from the ITO film containing 0.2 wt% tantalum annealed at 500°C and the average optical transmittance is over 95% from 425 nm to 460 nm.


2010 ◽  
Vol 663-665 ◽  
pp. 1293-1297 ◽  
Author(s):  
Yue Bo Wu ◽  
Sheng Lei ◽  
Zhe Wang ◽  
Ru Hai Zhao ◽  
Lei Huang ◽  
...  

The Al-doped ZnO (AZO) films were deposited on the glass substrates by RF magnetron sputtering at different substrate temperatures. The effect of substrate temperature on the structural, optical, and electrical properties of AZO films was investigated. The results indicate each of the films has a preferential c-axis orientation. The grain size increases with substrate temperature increasing. All the films exhibit a high transmittance in visible region and have sharp ultraviolet absorption characteristics. The resistivity decreases with substrate temperature increasing up to 250oC, then increases for higher temperature.


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