Horng-Show Koo

Fabrication and chromatic characteristics of the greenish LCD colour-filter layer with nano-particle ink using inkjet printing technique

Inkjet-printed greenish color filter layer for the application of active-matrix TFT-LCD had been significantly fabricated by the modified inkjet printing technology. The greenish ink with nano-particle pigments was injected in the stripe-type pattern with 90 μm in width and 250 μm in length by pre-designed inkjet head and driving system, and only green color was tested. The height of transparent rib wall, prepared by lithographic processes, on black matrix is 5.0 μm. The chromatic coordinates of color filter with greenish subpixel patterns in CIE 1931 standard diagram can achieve in the region of x=0.3095±0.04, y=0.5912±0.04, brightness of Y=58.887 for 50 droplets and x=0.3103±0.04, y=0.5784±0.04, brightness of Y=60.328 for 41 droplets. The structural surface morphologies of the greenish subpixel patterns remain homogenous, smooth and flatten.

Physical chromaticity of colorant resist of color filter prepared by inkjet printing technology

A color filter with stripe-type pattern of bluish colorant film has been manufactured by the emerging inkjet printing technology. The injected colorant film in subpixel cells increases its thickness with increasing amount of bluish ink droplets with nanoparticles pigment during the processing of inkjet printing. The specified magnitude of bluish colorant ink for color filter in chromatic characteristics can be achieved in the neighboring region of x=0.149±0.04, y=0.152±0.04 and a brightness of Y=21.4. The visible light transmittance ratio of the prepared color filter samples with bluish colorant ink can nearly achieve 100% over the wavelength of 450–500nm, this is due to the reduction of light scattering in colorant film with particle size in nanometer.

Effect of Ca2PbO4 additions on the formation of the 110 K phase in Bi‐Pb‐Sr‐Ca‐Cu‐O superconducting ceramics

The growth of the Bi2Sr2Ca2Cu3Ox phase in the high Tc superconducting Bi‐Pb‐Sr‐Ca‐Cu‐O system through reacting Bi2Sr2CaCu2Ox with Ca‐ or Cu‐rich intermediate phases, Ca2CuO3, CuO, and Ca2PbO4, has been studied. X‐ray diffraction and electrical and diamagnetic analyses revealed that the interaction and interdiffusion of these intermediate phase led to the formation of a high percentage of the 2223 phase and a sharp single‐step superconducting transition at Tc(R = 0) = 108 K. Also, Ca2PbO4 proved essential for accelerating the growth rate of the 110 K phase from the 85 K phase.

Synthesis of high-Tc superconducting Bi-Pb Sr-Ca-Cu-O ceramics prepared by an ultrastructure processing via the oxalate route

The oxalate precursor yielded by a sol-gel processing can be pyrolysed and oxidized at 840 ° C for 40h into the desired high-Tc superconductor in the lead-doped Bi-Sr-Ca-Cu-O system withTc(onset) = 140 K andTc(zero) = 104K. The mechanisms of the sol-gel reaction were monitored by analysis of Fourier transformation infrared (FTIR) spectroscopy. Moreover, identification of the various phases existing on the specimens after firing at selected temperatures, was made by analysis by FTIR spectroscopy and X-ray diffractometry. Based on the experiment results, the mechanisms of forming Bi2Sr2CaCu2O8+δ (phase 2212) might be identified as the reaction of Bi2Sr2CuO6+δ, Ca2CuO3 and CuO at 800 ° C. Furthermore, Bi2Sr2Ca2Cu3O10+δ (phase 2223) might be synthesized by the reaction of phase 2212, Ca2CuO3 and CuO at 840 ° C. Ca2PbO4 found in lead-doped materials may catalyse the formation reaction of Ca2CuO3 at 650 ° C and play a role of a flux to fuse Bi2Sr2CaCu2O8+δ, CuO and residual Ca2CuO3 and then improve the further synthesis of Bi2Sr2Ca2Cu3O10+δ at 840 δ C.

Preparation of HIGH-Jc superconducting oxide in the Bi-Sr-Ca-Cu-O system by oxalate gel processing

Abstract The high- T c superconducting oxide in the Bi-Sr-Ca-Cu-O system, with superconducting transition temperature at about 80 K, has been fabricated by the sol-gel method using oxalic acid and nitrates as starting materials. Compared to the conventional solid-state reaction method, this chemical technique offers less fabricating time and lower sintering temperature to get a homogeneous superconductor. Thermal analysis, infrared spectra and X-ray diffraction data indicate that the mechanisms of decomposition and phase transformation of specimens prepared at various temperatures are greatly different.

Preparation of high-Tc superconducting Bi-Pb-Sr-Ca-Cu-O ceramics by the method of thermal decomposition of an ethylene diamine tetra-acetate colloidal suspension

High-Tc superconducting Bi-Pb-Sr-Ca-Cu oxide with Tc (zero) of 108 K was obtained by ultrastructure processing via the EDTA route, using nitrates as the starting materials. Excellent sinterability of precursor induced by the EDTA processing permits a relatively short time to achieve the desirable Bi-based superconducting compound compared with that obtained by the traditional solid-state reaction method. Fourier transform-infrared spectroscopy, thermal analysis, X-ray diffraction analysis and energy-dispersive X-ray fluorescence analysis were employed in this study to elucidate the reaction mechanisms and/or identify the phase transformations.

Flexible and superconducting properties of sintered Bi-Pb-Sr-Ca-Cu-O tapes

Flexible Bi1.81Pb0.43Sr1.71Ca2.14Cu3Ox superconducting tapes have been fabricated by the powder‐in‐silver tubing technique followed by appropriate sintering. The sintered tape, Jc≳104 A/cm2 at 77 K, can be bent into an arc with a 0.9‐cm radius of curvature without deteriorating the transport properties at liquid nitrogen temperature. This indicates that the superconducting a‐b plane of the Bi‐based tape has a strain of 0.05%–0.1%.

Synthesis and characterization for a new family of Tl-containing septenary oxides with Tc,zero above 105 K

Abstract Bulk superconductivity with Tc,zero above 105 K in Tl 0.5 Pb 0.5 (Ca 1−x A x )Sr 2 Cu 2 O y oxides (x=0.2, A=Y and rare-earth elements La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) with YBa 2 Cu 3 O y -like structure was observed. For A=Ce and mischmetal, Tc,zero was found to be 95 K and 101K with x=0.1. The results represent one of the few cases where chemical substitution has significantly raised Tc in a known compound. Single phase samples were prepared and were found to be highly reproducible and stable. Furthermore, the preparation conditions are much less stringent than those of other copper-based high-Tc superconductors.

Apparatus for extinguishing a lighted cigarette

An apparatus for extinguishing a lighted cigarette comprises a hollow external seat and a storing container. A blade for cutting and extinguishing the burning portion of a lighted cigarette in combination with an L-shaped plate are provided within a seat. Both the plates are made from shape memory alloys having different temperature reaction gradients. When the burning portion of a cigarette is placed into the seat and comes into contact with the blade, the plate will restore to its memory shape by the temperature response in cutting off the lighted portion of the cigarette and extinguishing the lighted portion by pressing it on the L-shaped plate. The L-shaped plate stretches straight to let the cigarette ash drop into the storing container. When the temperature of the L-shaped plate is decreased, the plate recovers to its original position to cover the storing container. The cigarette ash is thus restricted within the storing container to prevent it from dispersing and causing pollution. A lighter is detachably inserted into the apparatus and facilitates carrying and provides a safe and clean environment.

Effect of Ag2O additive on microstructure and superconductivity of the Tl2Ba2Ca2Cu3Oy compound

A series of Ag‐doped Tl2Ba2Ca2Cu3Oy superconducting oxides were prepared by a solid‐state reaction and the influence of Ag2O content, with a varying molar ratio which ranged from 0 to 1.0, was also investigated. The normal‐state resistance of the samples decreased with an increase in the content of Ag2O additive, while the critical superconducting temperatures of the Ag‐doped samples increased once the Ag2O content was increased. The doping of the silver oxide was indicated from the results of the x‐ray diffraction pattern to be favorable to the formation of the three CuO layers with a high‐Tc phase Tl2Ba2Ca2Cu3Oy. The diamagnetic property of the samples was also confirmed by the magnetic measurements to become enhanced by doping with silver oxide. The platelike grains of Tl2 Ba2CaCu2Oy phase were observed from scanning electron micrographs to be primarily present in the undoped sample, while the amount of the needlelike Tl2Ba2Ca2Cu3Oy grain increased with an increase in the doping amount of Ag2O.