Liquid crystal displays (LCDs) with Ga-doped ZnO (GZO) transparent electrodes on RGB color filters were fabricated to demonstrate the feasibility of using this new material as an alternative to ...indium tin oxide (ITO) electrodes. The process flow for fabricating LCDs with GZO electrodes was entirely compatible with that for commercially available LCDs using ITO electrodes. Concurrently, photolithography processing and wet-chemical etching techniques for the formation of GZO transparent electrodes on thin film transistor (TFT) arrays in LCD panels was developed. Fine-patterns of GZO with 2-μm line widths were successfully formed using lithography and wet -etching technology with a weakly acidic etchant of pH 5.5–6.8.
In this paper, high-performance bottom-gate thin-film transistors (TFTs) with transparent zinc oxide (ZnO) channels have been developed. The ZnO film for active channels was deposited by RF magnetron ...sputtering. The crystallinity of the ZnO film drastically improved when it was deposited on a doublelayer SiO x /SiN x gate insulator. In order to achieve a ZnO TFT back-plane for liquid-crystal display (LCD) with the required pattern accuracy, dry etching of the ZnO film in an Ar and CH 4 chemistry has been developed. The etching rate and tapered profile of the ZnO film could be controlled by the Ar content in the etching gases of Ar and CH 4 . The saturation mobility (mu sat ) of the ZnO TFT strongly depended on a gate voltage. A mu sat of 5.2 & cm 2 .(V .s) -1 at V GS = 40 V and V DS = 10 V, and an on/off-current ratio of 2.7 x 10 7 were obtained. A drain-current uniformity of plusmn7% was achieved within a radius of 20 mm from the substrate center. A 1.46 -in diagonal LCD with 61 600 pixels has been driven by the ZnO-TFT back-plane. A moving picture image was available on fabricated LCD driven by the ZnO TFTs.
This paper presents a method to control the stereo stage width to provide additional functionality to a stereophonic sound-field recording/reproduction system that uses two microphones and two ...loudspeakers. The proposed method interpolates or extrapolates the time-frequency representations of the left and right stereo signals according to the desired scaling magnification. A mathematical analysis is introduced that clarifies the scaling ability of the proposed method. Listening tests using a stereo signal consisting of a mixture of two speech signals with different time-lags are performed. The results indicate that the two stereo signals yield almost the same aural impression when the scaling magnification is under two and the following two requirements are satisfied. 1) The time-lags in the stereo signal are scaled strictly before mixing. 2) The time-lags are scaled approximately by the proposed method after mixing. The listening tests also clarified the superiority of the proposed method in terms of the sound quality with respect to conventional methods
Influence of thermal annealing on electrical properties of GZO films has been studied by means of Hall effect measurements and optical characterization based on Drude model analysis for transmission ...and reflection spectra. Electrical resistivity increased with increasing annealing temperature. Changes of electrical properties were compared between air and N2 gas atmosphere. Thermal stability in the air was worse compared to the N2 gas atmosphere. Annealing at rather high temperature caused decrease in the Hall mobility and increase in optical mobility. The difference between the Hall mobility and the optical mobility was attributed to carrier scattering at grain boundaries. Three kinds of deposition method, ion plating using DC arc discharge, DC magnetron sputtering, and RF power superimposed DC magnetron sputtering were compared in terms of the thermal stability.
We have used high-resolution X-ray photoelectron spectroscopy (XPS) to investigate the molecular dependence on sulfur chemical states of organosulfur monolayers of alkanethiol, dialkyl disulfide, ...monosulfide, thiophene, and aromatic thiols on a Au(111) surface. When monosulfides or thiophenes adsorbed on the Au surface, the S(2p) peaks appeared between 161 and 164 eV, and peak fitting revealed that these organosulfurs exhibited almost the same peaks as those of alkanethiol and dialklyl disulfide monolayers. The monolayer made from monosulfide with shorter alkyl chains exhibited almost the same S(2p) XPS spectrum as the typical alkanethiol or dialkyl disulfide monolayers. Another S(2p3/2) peak appeared for aromatic derivatized thiol SAMs at around 161 eV, in addition to strong doublet S(2p) peak observed at 162.0 and 163.3 eV in the S(2p) spectra. The 161 eV peak was observed even in the S(2p) XPS spectra of alkanethiol or dialkyl disulfide monolayers, at the initial stage of monolayer growth or after low-temperature (∼ 100 °C) annealing of low molecular density alkanethiol SAMs. We consider that this 161 eV peak can be formed without molecular decomposition as well as due to the atomic sulfur produced by C−S cleavage.
Following the proposal of a new structural model by Fenter et al. (Science 1994, 266, 1216), several reports have indicated the existence of dimers in a self-assembled monolayer (SAM) film on Au ...(111). We synthesized an asymmetric disulfide with hydrocarbon and fluorocarbon chains, and observed phase-separated domains in the SAM film with force microscopy after annealing at 100 °C for 8 h. The phase separation clearly shows the cleavage of the S−S bond of the disulfide in the film. Although it cannot be confirmed whether the phase-separated domains consist of exchanged dimers or monomers (thiolates), we obtained new insights into the stability and diffusion of molecules in SAM films.
Magnetic impulse welding is a joining process in which lap joint surfaces of cylindrical materials, such as, pipes, are pressure welded using electromagnetic force. This process causes little decline ...in material strength due to thermal effects and little formation of brittle intermetallic compounds compared with general welding processes; the process is suitable for joining thin walled pipes of dissimilar metals and avoids the need for any binder for dissimilar metal joining. In addition, no special pressurising equipment is required and, because it is a simple process with the capability of joining within a short timescale, this process is expected to be employed as a technique which can be applied for on site pipework operations. In this study trials were carried out on magnetic impulse welding of aluminium pipes or copper pipes with similar/dissimilar metal cores with the aim of ensuring that this technique can be practically applied to pipework joints used in refrigerators and air conditioning systems. In particular, specimens without taper were employed, in order to simplify machining of the cores prior to welding; an investigation into the welding conditions was carried out so that the pressure resistance and the weld strength required at pipework joints could be obtained from consideration of plastic deformation of the cores and whether the weld interfaces had been degreased. Materials include 1050, C1020, 1100, C1100 alloys and C3604 brass and SS400 steel.
