Nanostructured TiO2 arrays were prepared through a facile and environmentally friendly hydrothermal method on fluorine-doped tin oxide coated glass substrates with tunable surface morphologies without using any catalysts, seeds or templates. Their crystal structure, surface morphology, compositions and wettability were investigated by X-ray diffraction, field emission scanning electron microscope, X-ray photoelectron spectroscope and contact angle measurements, respectively. It is found that the concentration of hydrochloric acid has a great influence on the morphology and wettability of TiO2 nanorod films. Typically, the film prepared with 7.0M HCl exhibits a high water contact angle of 157.3±1.5° with an advancing contact angle of 154.2±1.3° and a receding contact angle of 161.2±1.3° and a small sliding angle of 7° after hydrophobic treatment. The Cassie theory was used to analyze the hydrophobic phenomenon of the as-prepared film, and it reveals that only about 9% of the water surface is contacted with the TiO2 film and the remaining 91% is contacted with the air cushion, which is reasonable for the hydrophobicity of a TiO2 nanorod film.

Pure ZnO film exhibits high resistivity,electrical properties performance instability,thereby,how to enhance its electrical and optical properties by doping is a key for its application.In the paper,the recent progress of the studies on Sn-doped ZnO(ZnO:Sn) thin films based on the factors such as the prepreparation methods,doped concentration,growth conditions and annealing to affect the opto-electrical properties of the films are summarized.The ways to decrease the resistivity and enhance the transmittance of ZnO:Sn thin film are put forward.

Tin doped zinc oxide(TZO) thin films were prepared by radio frequency magnetron sputtering on quartz glass substrates.The concentration of Sn element in the powder target was 0.5% in atomic ratio.The effect of substrate temperature on the structural,surface morphologies,electrical and optical properties of the ZnO∶Sn thin films was investigated.It was found that the as-deposited film is C-axis perpendicular to the substrate.The lowest resistivity(2.619×10-2Ω·cm),and the best crystal quality were obtained at 400℃.In the visible region,the films were with good transmittance.

A novel super-hydrophobic coating was prepared by chemical modification on the anodized aluminum alloy surface. The surface structure was characterized by water contact angle measurement, scanning electron microscopy (SEM), and the composition was measured by X-ray photoelectron spectroscopy (XPS). The corrosion behavior of the super-hydrophobic coating was evaluated by the polarization curve and the electrochemical impedance spectroscopy ( EIS). It was found that the static water contact angle on the surface of super-hydrophobic coating was as high as 167.7 +/- 1.2 degrees, and the sliding angle was 5 degrees. The super-hydrophobic coating resulted in excellent corrosion resistance property and the super-hydrophobic coating showed a good stability. (C) 2011 Elsevier B.V. All rights reserved.

A series of oriented hexagonal wurtzite ZnO nanorod-array films were grown on fluorine-doped tin oxide (FTO) coated glass substrates by chemical process. The effect of polyethyleneimine (PEI) on the structure and micro-morphology of ZnO nanorod array films, as well as the photoelectric conversion properties in dye-sensitized solar cells (DSSCs) was analyzed. It was found that with the addition of PEI in growth solution, the ZnO nanorods became smaller in diameter and longer in length and hence the dye absorption and the photovoltaic performance of DSSCs were improved. A power conversion efficiency of 2.30% had been achieved on a DSSC based on a 7.9 mu m-long nanorod array film prepared by a growth solution containing the PEI. (C) 2011 Elsevier B.V. All rights reserved.

W(VI) is doped into TiO2 via a sol-gel method, and the crystalline anatase structure is well preserved with the W content ranging from 0.1% to 5%. The conduction band (CB) of TiO2 moves downward (i.e., positive shift) gradually with increasing the W content from 0.1% to 2% and then stays almost unchanged with increasing the W content from 2% to 5%. Dye-sensitized solar cells (DSSCs) based on the W-doped anatase TiO2 show an advantage in repressing the charge recombination. The electron lifetime in the DSSC is significantly improved by the W-doping. As a result of the positive shift of the CB and repressed charge recombination, the short-circuit photocurrent (J(sc)) of the DSSC is improved remarkably. The collective effect of the positive shift of the CB and the enhanced electron lifetime caused by the W-doping makes the open-circuit photovoltage (V-oc) remain almost unchanged below 0.5% W-doping and decrease above 0.5% W-doping. The highest power conversion efficiency (eta = 9.1%) is obtained at 0.2% W-doping, which shows increases by 17% in J(sc) and by 20% in eta, as compared with the undoped DSSC.

A series of oriented rutile TiO2 nanorod-array films are in-situ grown on fluorine-doped tin oxide (FTO) coated glass substrates from a mixed acid solution containing titanium tetraisopropoxide (TTIP), hydrochloric acid (HCl), acetic acid (HOAc), and water (H2O) by means of hydrothermal reaction at 150 °C. The effect of HOAc in the titania growth solution on the structure and micro-morphology of TiO2 nanorod array films, as well as the photoelectric conversion properties in dye-sensitized solar cells (DSSCs) has been fully investigated. It is found that HOAc can facilitate the formation of uniform, dense, and vertically oriented TiO2 nanorods and hence improves the dye adsorption, electron diffusion coefficient, and the photovoltaic performance of DSSCs, typically in short-circuit photocurrent and power conversion efficiency. A power conversion efficiency of 4.03% has been achieved on a DSSC based on a 2.3 µm-long nanorod array film obtained from a mixed acid solution with the TTIP:HCl:HOAc:H2O ratio of 0.8:4:8:8 by volume.

Digitalwatermark technique is effective in protecting copyright of digital products and maintaining data security.Existing digital watermarking algorithms are mostly designed against gray images but few are for the color images.This paper presents a color image watermarking algorithm based on two dimension chaos encryption.Use the two dimension logistic chaotic map to generate the watermark.An original image is divided into non-overlapped blocks,fractional box-counting dimension is used to analyze the feature of the image blocks to extract the feature blocks and secondary feature blocks and then used one level DWT to decompose them.The different strength watermark is adaptively embedded into the low-frequency coefficients of the feature blocks,under the condition that the watermark embedded is invisible,and then is embedded into the secondary feature blocks in the same way when embedded watermarking.Experimental results demonstrate that the watermarking scheme is strongly robust to different types of attacks such as JPEG compression,noise addition,cropping,filtering and so on.

The In-doped ZnO films were deposited by RF magnetron sputtering on quartz glass substrates. The impacts of the deposition conditions, including In-doping levels, deposition rate and annealing temperature and time, on film growth were studied. The microstructures and properties of the In-doped ZnO were characterized with X-ray diffraction, scanning electron microscopy, photoluminescence spectroscopy and conventional probes. The results show that the In-doping and annealing significantly improved its microstructures and properties. For instance, In-doping promoted the c-axis preferred growth, reduced its resistivity from 28.9 Ω·cm to 4.3×10-3 Ω·cm, and widened its gap width. The annealing in air resulted in crystallization and a slight gap narrowing, possibly because of the reductions of the carrier density and lattice constants. Interesting finding was that the annealing resulted in a sharp increase of blue light intensity at 446 nm.

A series of Zn1-xMgxO(x=0.00-0.16) films have been prepared on quartz substrates by RF magnetron sputtering.Several characterization techniques,including X-ray diffraction(XRD),scanning electron microscope(SEM),UV-Vis spectrophotometer,and photoluminescence measurement,have been used to investigate the crystal structure,surface morphology,and optical properties of the films,respectively.The results reveal that the obtained films with Mg content x up to about 0.1 are without phase separation;the films are uniform with grain size in the range of 100-150 nm;the optical transmittance is over 80%,and the band gap(Eg) has linear relationship with Mg content:Eg=2.03x+3.26(eV);the PL spectra of the films are composed of the weaker UV emission band and stronger visible band,and UV emission peak has a blue shift with the increase of Mg content.

The latest development of the p-type transparent conducting CuAlO2 films with super-lattice structures was reviewed. The discussions centered on the film growth technologies, its energy band structure, its microstructures, and its thermoelectric properties. In addition, the impacts of the film growth conditions, such as the substrate temperatures, the annealing temperatures and the doping levels and doping modes, on its thermoelectric properties and its performance were also discussed. The technical problems to be solved were raised and possible ways to improve its performance in thermoelectric energy conversion were also proposed.

In-doped ZnO thin films were prepared on glass substrate by RF magnetron sputtering.The result of XRD and AFM shows that the films are polycrystalline with high c-axis orientation.The study of gas sensing reveals that the films are sensitive to NO2 and the best sensibility occurs at 273 ℃;the sensibility is concerned with the concentration of NO2 and the film thickness.The ZnO∶In films are more sensitive to the NO2 gas with higher concentration of NO2 and thinner films have a better sensitivity.Exposed to 2×10-5 NO2 at 273 ℃,the 90nm thick film has a sensibility of 16,indicating that ZnO∶In films can be used to measure NO2 with a low concentration.

Indium doped zinc oxide (ZnO : In) films were deposited on glass substrates by RF magnetron sputtering method using a powder target.The influence of the substrate temperature on the structure,optical and electrical properties was investigated by X-ray diffraction (XRD),atom force microscope (AFM),Hall measurement and optical transmission spectroscopy.The results show all the obtained films are polycrystalline with a hexagonal wurtzite structure and grow preferentially in the (002) direction,and the grain size is about 22～29 nm.The conductivity of the ZnO : In films change with the substrate temperature,and the lowest electrical resistivity is about 3.18 × 10~3 Ω·cm for the samples deposited at substrate temperature 100 ℃.The transmittance of our films in the visible range is all higher than 85%.