共查询到20条相似文献,搜索用时 31 毫秒
1.
S. G. Pawar S. L. Patil M. A. Chougule B. T. Raut S. A. Pawar R. N. Mulik V. B. Patil 《Journal of Materials Science: Materials in Electronics》2012,23(1):273-279
Nanocrystalline titanium oxide thin films have been deposited by spin coating technique and then have been analyzed to test
their application in NH3 gas-sensing technology. In particular, spectrophotometric and conductivity measurements have been performed in order to determine
the optical and electrical properties of titanium oxide thin films. The structure and the morphology of such material have
been investigated by X ray diffraction, Scanning microscopy, high resolution electron microscopy and selected area electron
diffraction. The X-ray diffraction measurements confirmed that the films grown by this technique have good crystalline tetragonal
mixed anatase and rutile phase structure. The HRTEM image of TiO2 thin film showed grains of about 50–60 nm in size with aggregation of 10–15 nm crystallites. Selected area electron diffraction
pattern shows that the TiO2 films exhibited tetragonal structure. The surface morphology (SEM) of the TiO2 film showed that the nanoparticles are fine with an average grain size of about 50–60 nm. The optical band gap of TiO2 film is 3.26 eV. Gas sensing properties showed that TiO2 films were sensitive as well as fast in responding to NH3. A high sensitivity for ammonia indicates that the TiO2 films are selective for this gas. 相似文献
2.
In the present study, Ag/SiO2–TiO2 thin films on ceramic tiles with glazed surface were successfully prepared by a liquid phase deposition method (LPD) at a
low temperature. The Ag/SiO2–TiO2 thin films obtained were homogenous, well adhered and colored by interference of reflected light. The films were characterized
by scanning electron microscopy and X-ray diffraction. From these analysis data, it was found that silver (Ag) nanoparticles
were trapped in SiO2–TiO2 matrix. The antibacterial effects of Ag/SiO2–TiO2 thin films against S. aureus and E. coli were examined by the so-called antibacterial-drop test. The bactericidal activity for the above bacteria cells was estimated
by relative number of bacteria survived calculated from the number of viable cells which form colonies on the nutrient agar
plates. The Ag/SiO2–TiO2 thin films had an excellent antibacterial performance. Atomic absorption spectroscopy (AAS) was used for the quantitative
determination of the Ag ion concentration releasing from the Ag/SiO2–TiO2 thin film. The releasing rate of Ag ions from the Ag/SiO2–TiO2 film is 0.123 μg/mL during 192 h. The antibacterial effect of Ag/SiO2–TiO2 thin film before and after aging in a weathering chamber for 48 h was compared and the results show that the antibacterial
activity is not compromised after weathering. 相似文献
3.
In this study, we have studied the effect of repeated annealing temperatures on TiO2 thin films prepared by dip-coating sol–gel method onto the glasses and silicon substrates. The TiO2 thin films coated samples were repeatedly annealed in the air at temperatures 100, 200, and 300 °C for 5 min period. The
dipping processes were repeated 5 to 10 times in order to increase the thickness of the films and then the TiO2 thin films were annealed at a fixed temperature of 500 °C for 1 h period. The effect of repeated annealing temperature on
the TiO2 thin films prepared on glass substrate were investigated by means of UV–VIS spectroscopy, X-ray diffraction (XRD), and atomic force microscopy (AFM). It was observed that the thickness, average crystallite size, and average grain size of TiO2 samples decreased with increasing pre-heating temperature. On the other hand, thickness, average crystallite size, and average
grain size of TiO2 films were increased with increasing number of the layer. Al/TiO2/p-Si metal–insulator–semiconductor (MIS) structures were obtained from the films prepared on p-type single silicon wafer
substrate. Capacitance–voltage (C–V) and conductance–voltage (G/ω–V) measurements of the prepared MIS structures were conducted at room temperature. Series resistance (R
s) and oxide capacitance (C
ox) of each structures were determined by means of the C–V curves. 相似文献
4.
Guang-rui Gu Zhi HeYan-chun Tao Ying-ai LiJun-jie Li Hong YinWei-qin Li Yong-nian Zhao 《Vacuum》2003,70(1):17-20
The conductivity of nanometer TiO2 thin films was presented in this paper. The dependence of the conductivity of TiO2 thin films on the thickness of the film and the substrate material were educed. The TiO2 films were deposited by reactive magnetron sputtering of a Ti targets in an Ar+O2 mixture in a conventional sputtering reactor. The thickness of the films deposited on Ti varied in the range from 15 to 225 nm. The resistivity of the films was measured at room temperature in the air. It was found that the conductivity of TiO2 thin films varies in the range from conductor, semiconductor to nonconductor. This was attributed to electrons transfer at the interface between the TiO2 and substrates, and the depth of electrons transfer was determined by the difference of work function. 相似文献
5.
Atsunori Matsuda Yugo Higashi Kiyoharu Tadanaga Masahiro Tatsumisago 《Journal of Materials Science》2006,41(24):8101-8108
SiO2–TiO2 spherical microparticles of about 0.7 μm in diameter were prepared by the sol–gel method. Anatase nanocrystals were formed in the microparticles and their specific surface area was increased after a hot-water treatment at 90 °C. From the changes in the concentration of I2 photocatalytically generated from KI aqueous solution, the activity of the SiO2–TiO2 microparticles was found to increase with increasing the hot-water treatment time. Particulate, thick films were electrophoretically deposited on indium tin oxide (ITO)-coated glass substrates using the anatase nanocrystal-precipitated SiO2–TiO2 microparticles. The thickness of the electrophoretically deposited particulate film increased to be approximately 10 μm with an increase in applied voltage. The resultant thick film showed a high photocatalytic activity. 相似文献
6.
Prabitha B. Nair V. B. Justinvictor Georgi P. Daniel K. Joy P. V. Thomas 《Journal of Materials Science: Materials in Electronics》2013,24(7):2453-2460
TiO2 thin films were deposited onto quartz substrates by RF magnetron sputtering. Inorder to investigate the effect of film thickness on the structural and optical properties, films were deposited for different time durations, and post-annealed at 873 K. The influence of annealing atmosphere (air/oxygen) on the film properties was also investigated. The films were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis spectroscopy and photoluminescence (PL) spectroscopy. Films deposited at different time durations are amorphous-like in nature. From XRD patterns it can be inferred that deposition for longer duration is essential for achieving crystallisation in TiO2 thin films prepared by RF magnetron sputtering. The films exhibited good adherence to the substrate and are crack free as revealed by SEM images. Film thickness was found to increase with increase in sputtering time. The optical band gap of the films was found to decrease with increase in film thickness, which is consistant with XRD observations. Film thickness did not show any significant variation when annealed in both air and oxygen. Defect related PL emission in the visible region (blue) was observed in all the investigated films, which suggests the application of these films in optoelectronic display devices. 相似文献
7.
Influence of deposition parameters on preferred orientation of RF magnetron sputtered BST thin films
Songzhan Li Yanqin Yang L. Liu T. J. Zhang W. H. Huang 《Journal of Materials Science: Materials in Electronics》2008,19(3):223-226
Ba0.65Sr0.35TiO3 (BST) thin films have been deposited by radio frequency magnetron sputtering. The effects of the deposition parameters on
the crystallization and microstructure of BST thin films were investigated by X-ray diffraction and field emission scanning
electron microscopy, respectively. The crystallization behavior of these films was apparently affected by the substrate temperature,
annealing temperature and sputtering pressure. The as-deposited thin films at room temperature were amorphous. However, the
improved crystallization is observed for BST thin films deposited at higher temperature. As the annealing temperature increased,
the dominant X-ray diffraction peaks became sharper and more intense. The dominant diffraction peaks increased with the sputtering
pressures increasing as the films deposited at 0.37–1.2 Pa. With increasing the sputtering pressure up to 3.9 Pa, BST thin
films had the (110) + (200) preferred orientation. Possible correlations of the crystallization with changes in the sputtering
pressure were discussed. The SEM morphologies indicated the film was small grains, smooth, and the interface between the film
and the substrate was sharp and clear. 相似文献
8.
M. Öztaş M. Bedir R. Kayalı F. Aksoy 《Journal of Materials Science: Materials in Electronics》2006,17(10):841-845
InP thin films were prepared by spray pyrolysis technique using aqueous solutions of InCl3 and Na2HPO4, which were atomized with compressed air as carrier gas. The InP thin films were obtained on glass substrates. Thin layers
of InP have been grown at various substrate temperatures in the range of 450–525°C. The structural properties have been determined
by using X-ray diffraction (XRD). The changes observed in the structural phases during the film formation in dependence of
growth temperatures are reported and discussed. Optical properties, such as transmission and the band gap have been analyzed.
An analysis of the deduced spectral absorption of the deposited films revealed an optical direct band gap energy of 1.34–1.52 eV
for InP thin films. The InP films produced at a substrate temperature 500°C showed a low electrical resistivity of 8.12 × 103 Ω cm, a carrier concentration of 11.2 × 1021 cm−3, and a carrier mobility of 51.55 cm2/Vs at room temperature. 相似文献
9.
A transparent, high purity titanium dioxide thin film composed of densely packed nanometer sized grains has been successfully
deposited on a glass substrate at 30°C from an aqueous solution of TiO2-HF with the addition of boric acid as a scavenger by liquid phase deposition technique. From X-ray diffraction measurement,
the deposited film was found to be amorphous and turns crystalline at 500°C. The deposited film showed excellent adherence
to the substrate and was characterized by homogeneous flat surface. TiO2 thin films can be used as a photocatalyst to clean up organohalides, a class of compound in pesticides that pollute the ground
water. Photocatalytic degradation experiments show that indanthrene golden orange dye undergoes degradation efficiently in
presence of TiO2 thin films by exposing its aqueous solution to ultraviolet light. The suitable surface structure and porosity increases the
photocatalytic activity. It was also observed that hemin doped TiO2 thin films break up organohalides at a surprisingly high rate under visible light. 相似文献
10.
Photocatalytically active TiO2 thin-films were deposited on silicon wafers using the Successive-Ionic-Layer-Adsorption-and-Reaction technique and subsequent hydrothermal and/or furnace annealing. Atomic-force-microscopy images and X-ray diffraction measurements of the TiO2 films obtained under various annealing conditions show how changes of the micro-scale surface structure depend on the post-SILAR treatment. The hydrogen evolution over various TiO2 films was measured. Hydrothermally treated TiO2 films show a higher photocatalytic activity and a much better mechanical stability compared to furnace-annealed films. The optical transmittance of TiO2 thin films on glass substrates was also studied. A red shift was observed with increasing film thickness. TiO2 nanoparticles (∼10 nm) that were peeled off from the TiO2 films were investigated using high-resolution-transmission-electron-microscopy. 相似文献
11.
Y. K. Vayunandana Reddy D. Mergel 《Journal of Materials Science: Materials in Electronics》2006,17(12):1029-1034
Conductive ruthenium oxide (RuO2) thin films have been deposited at different substrate temperatures on various substrates by radio-frequency (rf) magnetron sputtering and were later annealed at different temperatures. The thickness of the films ranges from 50 to 700 nm. Films deposited at higher temperatures show larger grain size (about 140 nm) with (200) preferred orientation. Films deposited at lower substrate temperature have smaller grains (about 55 nm) with (110) preferred orientation. The electrical resistivity decreases slightly with increasing film thickness but is more influenced by the deposition and annealing temperature. Maximum resistivity is 861 μΩ cm, observed for films deposited at room temperature on glass substrates. Minimum resistivity is 40 μΩ cm observed for a thin film (50 nm) deposited at 540°C on a quartz substrate. Micro-Raman investigations indicate that strain-free well-crystallized thin films are deposited on oxidized Si substrates. 相似文献
12.
Nanocrystalline anatase TiO2 thin films with different thicknesses (0.5-2.0 μm) have been deposited on ITO-coated glass substrates by a sol-gel method and rapid thermal annealing for application as the work electrode for dye-sensitized solar cells (DSSC). From the results, the increases in thickness of TiO2 films can increase adsorption of the N3 dye through TiO2 layers to improve the short-circuit photocurrent (Jsc) and open-circuit voltage (Voc), respectively. However, the Jsc and Voc of DSSC with a TiO2 film thickness of 2.0 μm (8.5 mA/cm2 and 0.61 V) are smaller than those of DSSC with a TiO2 film thickness of 1.5 μm (9.2 mA/cm2 and 0.62 V). It could be due to the fact that the increased thickness of TiO2 thin films also resulted in a decrease in the transmittance of TiO2 thin films thus reducing the incident light intensity on the N3 dye. An optimum power conversion efficiency (η) of 2.9% was obtained in a DSSC with the TiO2 film thickness of 1.5 μm. 相似文献
13.
TiO2 thin films were experimentally coated on glass beads by means of a rotating cylindrical plasma chemical vapor deposition (PCVD) reactor. The morphologies and growth rates of the TiO2 thin films before and after heat treatment were measured for various process conditions. The precursors for the TiO2 films were generated from TTIP by plasma reactions, and they were deposited on the glass beads to become TiO2 thin films. The TiO2 thin films coated on the glass beads became more uniform by heat treatment. The TiO2 thin films grew more quickly on the glass beads with increasing mass flow rate of TTIP, reactor pressure, or rotation speed of the reactor. As the applied electric power decreases, the thickness of the thin films on the glass beads increases. This experimental study shows that the use of a rotating cylindrical PCVD reactor can be a good method to coat high-quality TiO2 thin films uniformly on particles. 相似文献
14.
Maria Teresa Vieira Ana S. Ramos José M. Castanho João C. Oliveira Albano Cavaleiro 《Journal of Materials Science》2007,42(22):9145-9153
This paper reviews thin films constituted by elements based on the Ti–Al–N system, bearing in mind the role of the condensed
phases in the development of structural components and functional devices. In recent decades, the Ti–Al, Ti–N and Al–N nanocrystalline
binary systems have rapidly attracted research and industry interest. These systems have revealed a great performance via
atomic-level structural control, making it possible to tailor new atomic structures and morphologies suitable in different
applications as protective and hard coatings and as thermal/diffusion barriers. The binary phases based on nitrogen were the
first to exhibit a wealth of interesting mechanical and electrochemical behaviours. However, more recently the Ti-Al and,
particularly, the Ti1 − x
Al
x
N thin films have been applied with success in the industry. The purpose of this paper is to compile the master results concerning
the production and characterisation of binary and ternary thin films of the Ti–Al–N system using similar deposition strategies.
These materials form a good base to analyse the correlation between the chemical composition and the atomic structure, the
preferred orientations and the morphology of 2D monolithic materials. The deposition strategies adopted and the thin films’
chemical compositions determine the as-deposited structures and, consequently, the mechanical behaviour of the thin films
produced, particularly the hardness. In general, an intermediary amorphous stage is observed, i.e., the thin films exhibit
a loss of crystallinity in the transition from a saturated solid solution to a new compound. 相似文献
15.
Tianjin Zhang Jinzhao Wang Baishun Zhang Juan Jiang Runkun Pan Jun He 《Journal of Materials Science: Materials in Electronics》2007,18(8):877-882
(Ba1 − x
Sr
x
)TiO3 (BST) thin films were deposited on Pt/Ti/SiO2/Si and YSZ/Pt/Ti/SiO2/Si substrates by radio frequency (RF) magnetron sputtering. The influence of YSZ interlayer on microstructures and dielectric
properties of BST thin films were investigated by X-ray diffraction, atomic force microscopy, scanning electron microscopy
and dielectric frequency spectra. It was found that the preferred orientation of BST thin films could be tailored by insertion
of YSZ interlayer and adjusting the thickness of YSZ interlayer. The BST thin films deposited on YSZ interlayer exhibited
a more compact and uniform grain structure than that deposited directly on Pt electrode. Dielectric measurement revealed that
the BST thin films deposited on 10 nm YSZ interlayer have the largest dielectric constant and a low dielectric loss tangent.
The enhanced dielectric behavior is mainly attributed to the YSZ interlayer which serves as an excellent seeding layer to
enhance the crystallization of subsequent BST films layer, and a smaller thermal stress field built up at the interface between
YSZ interlayer and BST film layer. 相似文献
16.
A. Srivastava R. K. Nahar C. K. Sarkar 《Journal of Materials Science: Materials in Electronics》2011,22(7):882-889
The effect of rapid thermal annealing on structural and electrical properties of high k HfO2 thin films is investigated. The films were initially deposited at pre-optimized sputtering voltage of 0.8 kV and substrate
bias of 80 V in order to get optimized results for oxide charges and leakage current as a MOS device. The film properties
were investigated for optimum annealing temperature in oxygen and optimum rapid thermal annealing temperature in nitrogen
respectively to get the best electrical results as a MOS device structure. The film thickness, composition and microstructure
is studied by Laser Ellipsometry, XRD and AFM and the effect of thermal annealing is shown. The electrical I–V and C–V characteristics
of the annealed dielectric film were investigated employing Al-HfO2-Si MOS capacitor structure. The flat-band voltage (V
fb) and oxide-charge density (Q
ox) were extracted from the high-frequency C–V curve. Dielectric study were further carried out on HfO2 thin films having metal–insulator–metal (MIM) configuration over a wide temperature (300–500 K) and frequency (100 Hz to
1 MHz) range. 相似文献
17.
Noor Shahina Begum H. M. Farveez Ahmed K. R. Gunashekar 《Bulletin of Materials Science》2008,31(5):747-751
The TiO2 thin films doped by Ni uniformly and non-uniformly were prepared on glass substrate from an aqueous solution of ammonium
hexa-fluoro titanate and NiF2 by liquid phase deposition technique. The addition of boric acid as an F
− scavenger will shift the equilibrium to one side and thereby deposition of the film is progressed. The rate of the reaction
and the nature of deposition depend on growing time and temperature. The resultant films were characterized by XRD, EDAX,
UV and SEM. The result shows that the deposited films have amorphous background, which becomes crystalline at 500°C. The EDAX
data confirms the existence of Ni atoms in TiO2 matrix. XRD analysis reveals the peaks corresponding to Ni but no peak of crystalline NiO was found. The transmittance spectra
of Ni uniformly and non-uniformly doped TiO2 thin films show ‘blue shift and red shift’, respectively. Ni-doped TiO2 thin films can be used as photocatalyst for the photodegradation of methyl orange dye. It was found that, organic dye undergoes
degradation efficiently in presence of non-uniformly Ni-doped TiO2 thin films when compared to uniformly doped films and pure TiO2 films under visible light. The photocatalytic activity increases with increase in the concentration of Ni in case of nonuniformly
doped thin films but decreases with the concentration when uniformly doped thin films were used. 相似文献
18.
Titanium dioxide (TiO2) thin films were prepared on Galvanized Iron (GI) substrate by plasma-enhanced atomic layer deposition (PE-ALD) using tetrakis-dimethylamido titanium and O2 plasma to investigate the photocatalytic activities. The PE-ALD TiO2 thin films exhibited relatively high growth rate and the crystal structures of TiO2 thin films depended on the growth temperatures. TiO2 thin films deposited at 200 °C have amorphous phase, whereas those with anatase phase and bandgap energy about 3.2 eV were deposited at growth temperature of 250 °C and 300 °C. From contact angles measurement of water droplet, TiO2 thin films with anatase phase and Activ™ glass exhibited superhydrophilic surfaces after UV light exposure. And from photo-induced degradation test of organic solution, anatase TiO2 thin films and Activ™ glass decomposed organic solution under UV illumination. The anatase TiO2 thin film on GI substrate showed higher photocatalytic efficiency than Activ™ glass after 5 h UV light exposure. Thus, we suggest that the anatase phase in TiO2 thin film contributes to both superhydrophilicity and photocatalytic decomposition of 4-chlorophenol solution and anatase TiO2 thin films are suitable for self-cleaning applications. 相似文献
19.
Noor Shahina Begum H. M. Farveez Ahmed O. M. Hussain 《Bulletin of Materials Science》2008,31(5):741-745
Boron doped TiO2 thin films have been successfully deposited on glass substrate and silicon wafer at 30°C from an aqueous solution of ammonium
hexa-fluoro titanate and boron trifluoride by liquid phase deposition technique. The boric acid was used as an F
− scavenger. The resultant films were characterized by XRD, EDAX, UV and microstructures by SEM. The result shows the deposited
film to be amorphous which becomes crystalline between 400 and 500°C. The EDAX and XRD data confirm the existence of boron
atom in TiO2 matrix and a small peak corresponding to rutile phase was also found. Boron doped TiO2 thin films can be used as photocatalyst for the photodegradation of chlorobenzene which is a great environmental hazard.
It was found that chlorobenzene undergoes degradation efficiently in presence of boron doped TiO2 thin films by exposing its aqueous solution to visible light. The photocatalytic activity increases with increase in the
concentration of boron. 相似文献
20.
N. M. Shah J. R. Ray V. A. Kheraj M. S. Desai C. J. Panchal Bharti Rehani 《Journal of Materials Science》2009,44(1):316-322
Copper indium diselenide (CuInSe2) compound was synthesized by reacting its elemental components, i.e., copper, indium, and selenium, in stoichiometric proportions
(i.e., 1:1:2 with 5% excess selenium) in an evacuated quartz ampoule. Structural and compositional characterization of synthesized
pulverized material confirms the polycrystalline nature of tetragonal phase and stoichiometry. CuInSe2 thin films were deposited on soda lime glass substrates kept at different temperatures (300–573 K) using flash evaporation
technique. The effect of substrate temperature on structural, morphological, optical, and electrical properties of CuInSe2 thin films were investigated using X-ray diffraction analysis (XRD), atomic force microscopy (AFM), optical measurements
(transmission and reflection), and Hall effect characterization techniques. XRD analysis revealed that CuInSe2 thin films deposited above 473 K exhibit (112) preferred orientation of grains. Transmission and reflectance measurements
analysis suggests that CuInSe2 thin films deposited at different substrate temperatures have high absorption coefficient (~104 cm−1) and optical energy band gap in the range 0.93–1.02 eV. Results of electrical characterization showed that CuInSe2 thin films deposited at different substrate temperatures have p-type conductivity and hole mobility value in the range 19–136 cm2/Vs. Variation of energy band gap and resistivity of CuInSe2 thin films deposited at 523 K with thickness was also studied. The temperature dependence of electrical conductivity measurements
showed that CuInSe2 film deposited at 523 K has an activation energy of ~30 meV. 相似文献