125results about How to "Improve surface morphology" patented technology

The present invention provides a method for preparing epitaxial-substrate, for growing a multilayered structure of GaN based semiconductor layers on the epitaxial-substrate so as to construct a semiconductor device such as blue-emitting laser diode and LED. The method for preparing the epitaxial-substrate encompasses (a) growing a first GaN based semiconductor layer on a bulk-substrate; (b) growing an InGaN based semiconductor layer on the first GaN based semiconductor layer; (c) growing a second GaN based semiconductor layer on the InGaN based semiconductor layer; and (d) separating the second GaN based semiconductor layer from the first GaN based semiconductor layer to provide the epitaxial-substrate. The epitaxial-substrate having a high crystallographic perfection and an excellent surface morphology is obtained simply and in a short time. The defect density of the single crystalline GaN based semiconductor layer film grown on the epitaxial-substrate is greatly reduced.

A vascular graft comprising a traditional graft material and an electrospun fibrous layer. The solvent used to reduce the material for the electrospun layer is also capable of reducing the graft material to a liquid solution. The electrospun layer is chemically bonded to the graft material, without adhesives, by either spraying the graft with the solvent prior to electrospinning or by assuring that a sufficient amount of residual solvent reaches the graft while electrospinning.

A sensor system that detects a current representative of a compound in a liquid mixture features a multi or three electrode strip adapted for releasable attachment to signal readout circuitry. The strip comprises an elongated support which is preferably flat adapted for releasable attachment to the readout circuitry; a first conductor and a second and a third conductor each extend along the support and comprise means for connection to the circuitry. The circuit is formed with single-walled or multi walled nanotubes conductive traces and may be formed from multiple layers or dispersions containing, carbon nanotubes, carbon nanotubes/antimony tin oxide, carbon nanotubes/platinum, or carbon nanotubes/silver or carbon nanotubes/silver-cloride. An active electrode formed from a separate conductive carbon nanotubes layer or suitable dispersion, positioned to contact the liquid mixture and the first conductor, comprises a deposit of an enzyme capable of catalyzing a reaction involving the compound and preferably an electron mediator, capable of transferring electrons between the enzyme-catalyzed reaction and the first conductor. A reference electrode also formed from a conductive carbon nanotube layer or suitable dispersion is positioned to contact the mixture and the second conductor. The system includes circuitry adapted to provide an electrical signal representative of the current which is formed from printing conductive inks made with nano size particles such as conductive carbon or carbon/platinum or carbon/silver, or carbon nanotubes/antimony tin oxide to form a conductive carbon nanotube layers. The multiple-electrode strip is manufactured, by then applying the enzyme and preferably the mediator onto the electrode. Alternatively the electrode can have a carbon nanotubes/antimony tin oxide, carbon nanotubes/platinum, or carbon nanotubes/silver or carbon nanotubes/silver-cloride surface and or a conductive carbon or silver ink surface connecting leg. The carbon nanotube solution is first coated and patterned into electro shapes and the conductive carbon nanotubes, carbon or silver ink can be attached by printing the ink to interface with the carbon nanotube electro surface. A platinum electrode test strip is also disclosed that is formed from either nano platinum distributed in the carbon nanotube layer or by application or incorporation of platinum to the carbon nanotube conductive ink.

Provided are semiconductor devices having improved surface morphology characteristics, and a method of fabricating the same. The semiconductor device includes: an r-plane sapphire substrate; an Al_xGa_(1-x)N(0≦×<1) buffer layer epitaxially grown on the r-plane sapphire substrate to a thickness in the range of 100-20000 Å in a gas atmosphere containing nitrogen (N₂) and at a temperature of 900-1100° C.; and a first a-plane GaN layer formed on the buffer layer.

The present invention provides a method of manufacturing a nitride semiconductor capable of improving the crystallinity and the surface state of the nitride semiconductor crystal formed on top of a high-temperature AlN buffer layer. An AlN buffer layer is formed on top of a growth substrate, and then nitride semiconductor crystals are grown on top of the AlN buffer layer. In a stage of manufacturing the nitride semiconductor, the crystal of the AlN buffer layer is grown at a high temperature of 900° C. or higher. In addition, an Al-source material of the AlN buffer layer is started to be supplied first to a reaction chamber and continues to be supplied without interruption, and then a N-source material is supplied intermittently.

Disclosed are certain polymeric compounds and their use as organic semiconductors in organic and hybrid optical, optoelectronic, and/or electronic devices such as photovoltaic cells, light emitting diodes, light emitting transistors, field effect transistors, and photodetectors. The disclosed compounds can provide improved device performance, for example, as measured by power conversion efficiency, fill factor, open circuit voltage, field-effect mobility, on/off current ratios, and/or air stability when used in photovoltaic cells or transistors. The disclosed compounds can have good solubility in common solvents enabling device fabrication via solution processes.

A method for electroplating a copper deposit onto a semiconductor integrated circuit device substrate having submicron-sized features, and a concentrate for forming a corresponding electroplating bath. A substrate is immersed into an electroplating bath formed from the concentrate including ionic copper and an effective amount of a defect reducing agent, and electroplating the copper deposit from the bath onto the substrate to fill the submicron-sized reliefs. The occurrence of protrusion defects from superfilling, surface roughness, and voiding due to uneven growth are reduced, and macro-scale planarity across the wafer is improved.

The invention relates to a carbon carrier of a proton exchange membrane fuel cell, in particular to a preparation method for carbon dry gel. The carbon dry gel is prepared by m-dihydroxybenzene, formaldehyde and a metal salt serving as raw materials, wherein the metal salt comprises a soluble nitrate, a carbonate, a sulfate, an acetate or a halide of one or more metal elements in an IVB group, a VB group, a VIB group, a VIIB group, a VIII group, an IB group and an IIB group; the m-dihydroxybenzene serving as a precursor and the formaldehyde are in the mol ratio of 2:1; the m-dihydroxybenzene and the metal salt are in the mol ratio of 10:1-500:1; and a high-stability carbon carrier is prepared by graphitizing mixed organic carbon dry gel at the high temperature of 1,500 to 3,500 DEG C. When serving as an anti-corrosion carbon material and being used as a cathode catalyst carrier of the proton exchange membrane fuel cell, the carbon dry gel has high anti-corrosion performance and high stability in an acidic and high-potential environment of cell operation.

A method for improving the growth morphology of (Ga,Al,In,B)N thin films on nonpolar or semipolar (Ga,Al,In,B)N substrates, wherein a (Ga,Al,In,B)N thin film is grown directly on a nonpolar or semipolar (Ga,Al,In,B)N substrate or template and a portion of the carrier gas used during growth is comprised of an inert gas. Nonpolar or semipolar nitride LEDs and diode lasers may be grown on the smooth (Ga,Al,In,B)N thin films grown by the present invention.

A method of fabricating a nonpolar gallium nitride-based semiconductor layer is provided. The method is a method of fabricating a nonpolar gallium nitride layer using metal organic chemical vapor deposition, and includes disposing a gallium nitride substrate with an m-plane growth surface within a chamber, raising a substrate temperature to a GaN growth temperature by heating the substrate, and growing a gallium nitride layer on the gallium nitride substrate by supplying a Ga source gas, an N source gas, and an ambient gas into the chamber at the growth temperature. The supplied ambient gas contains N₂ and does not contain H₂.

The ternary alloy CdSe_xTe_1-x(2 1 1) and the quaternary alloy Cd_1-zZn_zSe_xTe_1-x have been grown on Si(2 1 1) substrates using molecular beam epitaxy (MBE). The growth of CdSeTe is facilitated using a compound CdTe effusion source and a Se effusion source while the growth of CdZnSeTe is facilitated using a compound CdTe effusion source, a compound ZnTe effusion source, and an elemental Se source. The alloy compositions (x) and (z) of CdSe_xTe_1-x ternary compound and Cd_1-zZn_zSe_xTe_1-x are controlled through the Se/CdTe and ZnTe/CdTe flux ratios. The rate of Se incorporation is higher than the rate of Te incorporation as growth temperature increases. As-grown CdSeTe with 4% Se and CdZnSeTe with 4% Zn+Se, which is substantially lattice matched to long-wavelength infrared HgCdTe materials, exhibits excellent surface morphology, low surface defect density (less than 500 cm²), and a narrow X-ray rocking curve (a full-width at half maximum of 103 arcsec).

A nitride semiconductor laser device includes a p-type cladding layer, an active layer and an n-type cladding layer. The p-type cladding layer and the n-type cladding layer comprise indium and aluminum as group-III constituent. The n-type cladding layer, active layer and p-type cladding layer are arranged along the normal of a semi-polar semiconductor surface of a substrate. This surface tilts toward the m-axis of the hexagonal nitride by an angle of 63 degrees or more and smaller than 80 degrees from a plane orthogonal to a reference axis extending along the c-axis thereof. The active layer generates light having a peak wavelength in the range of 480 to 600 nm. The refractive indices of the n-type cladding layer and p-type cladding layer are smaller than that of GaN. The n-type cladding layer has a thickness of 2 μm or more while the p-type cladding layer has a thickness of 500 nm or more.

The application relates to the field of processing of a lithium battery, in particular to a cathode material, a preparation method thereof and a lithium ion battery containing the same. The cathode material comprises a lithium-containing cathode material and an indium oxide cladding layer coated on the surface of the lithium-containing cathode material. The preparation method comprises the following steps of: adding a soluble indium salt into a solution dissolved with an alkaline substance and stirring to form a sol; adding the lithium-containing cathode material into the sol and stirring to lead a generated sediment to be uniformly deposited and attached onto the surface of the lithium-containing cathode material; removing a liquid to obtain a lithium-containing cathode material solid body attached with the sediment; and roasting the lithium-containing cathode material solid body attached with the sediment to form the lithium ion cathode material coated with indium oxide on the surface. Compared with other inertia cladding materials such as aluminum oxide, the cathode material provided by the invention has the advantages that the electronic conductivity of indium oxide is excellent, and moreover, the discharging specific capacity, the cycling performance and the safety performance under high voltage can be obviously improved.

A method of manufacturing a ceramic includes forming a film which includes a complex oxide material having an oxygen octahedral structure and a paraelectric material having a catalytic effect for the complex oxide material in a mixed state, and performing a heat treatment to the film, wherein the paraelectric material is one of a layered catalytic substance which includes Si in the constituent elements and a layered catalytic substance which includes Si and Ge in the constituent elements. The heat treatment includes sintering and post-annealing. At least the post-annealing is performed in a pressurized atmosphere including at least one of oxygen and ozone. A ceramic is a complex oxide having an oxygen octahedral structure, and has Si and Ge in the oxygen octahedral structure.

A gallium nitride-based semiconductor optical device is provided that includes an indium-containing gallium nitride-based semiconductor layer that exhibit low piezoelectric effect and high crystal quality. The gallium nitride-based semiconductor optical device 11a includes a GaN support base 13, a GaN-based semiconductor region 15, and well layers 19. A primary surface 13a tilts from a surface orthogonal to a reference axis that extends in a direction from one crystal axis of the m-axis and the a-axis of GaN toward the other crystal axis. The tilt angle A_OFF is equal to the angle defined by a vector VM and a vector VN. The inclination of the primary surface is shown by a typical m-plane S_M and m-axis vector VM. The GaN-based semiconductor region 15 is provided on the primary surface 13a. In the well layers 19 in an active layer 17, both the m-plane and the a-plane of the well layers 19 tilt from a normal axis A_N of the primary surface 13a. The indium content of the well layers 19 is 0.1 or more.

The invention relates to a process for the synthesis of conducting polymer films by vapour phase polymerization. The invention relates particularly to the synthesis of polymerized thiophene films, for example poly(3,4-ethylenedioxythiophene) (PEDOT) films.

A method of manufacturing a nitride semiconductor device includes the step of forming a second nitride semiconductor layer having an inclined facet by metal-organic chemical vapor deposition, in which a molar flow ratio of a group V element gas to a group III element gas that are supplied to a growth chamber of a metal-organic chemical vapor deposition growth apparatus is set at 240 or less.

The invention relates to a preparation method of zirconium boride ceramic fibre, comprising the following steps of: (1) adding an aqueous solution containing a zirconium compound to an aqueous solution containing a boron compound, mixing evenly, dissolving a carbon source compound in the mixed solvent of ethanol and water, adding the mixed solvent of ethanol and water to the solution, adding an aqueous solution of complexing agents, mixing evenly, regulating pH value to be less than 4, and stirring for reaction for 10-16 hours to obtain a precursor solution; (2) mixing evenly a spinning addition agent and the precursor solution at the temperature between 30 and 70 DEG C and concentrating and defoaming the obtained mixture to obtain a precursor spinning solution of the zirconium boride ceramic fibre; (3) obtaining a precursor of the zirconium boride ceramic fibre from the spinning solution by a solvent spinning method at the temperature between 30 and 70 DEG C; and (4) obtaining the zirconium boride ceramic fibre by performing high temperature sintering on the precursor fibre. By adopting the method, ZrB2 ceramic nascent fiber with a better structure and performance can be obtained and the fiber with a promising prospect has the advantages of high temperature stability, low density, high heat conductivity and conductivity and the like.

A semiconductor laser device of the present invention includes: an active layer formed on a substrate; a first semiconductor layer formed on the active layer and made of a nitride semiconductor of a first conductivity type; a multilayer film formed on the first semiconductor layer and having a groove; and a second semiconductor layer formed on the multilayer film to fill the groove and made of a nitride semiconductor of the first conductivity type. The multilayer film is composed of a plurality of thin films containing a nitride semiconductor of a second conductivity type, and one of the thin films formed as the uppermost film is made of gallium nitride.