40 results about "Preferential growth" patented technology

Nanowhiskers are grown in a non-preferential growth direction by regulation of nucleation conditions to inhibit growth in a preferential direction. In a preferred implementation, <001> III-V semiconductor nanowhiskers are grown on an (001) III-V semiconductor substrate surface by effectively inhibiting growth in the preferential <111>B direction. As one example, <001> InP nano-wires were grown by metal-organic vapor phase epitaxy directly on (001) InP substrates. Characterization by scanning electron microscopy and transmission electron microscopy revealed wires with nearly square cross sections and a perfect zincblende crystalline structure that is free of stacking faults.

The present disclosure is directed to a method of producing metallic single-wall carbon nanotubes by treatment of carbon nanotube producing catalysts to obtain the desired catalyst particle size to produce predominantly metallic single wall carbon nanotubes. The treatment of the carbon nanotube producing catalyst particles involves contacting the catalyst particles with a mixture of an inert gas, like He, a reductant, such as H₂, and an adsorbate, like water, at an elevated temperature range, for example, at 500° C. to 860° C., for a sufficient time to obtain the catalyst particle size. In some of the present methods, the preferential growth of nanotubes with metallic conductivity of up to 91% has been demonstrated.

The invention relates to a flexible stainless steel substrate copper-indium-gallium-selenium film battery which has a combined structure comprising a stainless steel foil substrate and a multi-layer film, wherein the multi-layer film comprises a bottom electrode, an absorption layer, a buffer layer, an intrinsic ZnO layer, an aluminum-doped ZnO layer and a gate electrode which are superimposed together in order. A preparation method of the flexible stainless steel substrate copper-indium-gallium-selenium film battery comprises the following steps of: depositing a double-layer Mo back electrode on the stainless steel substrate by adopting a magnetron sputtering method; preparing a copper-indium-gallium-selenium absorption layer by adopting a three-step co-evaporation method; preparing a CdS buffer layer by adopting a chemical water bath method; preparing the intrinsic ZnO layer and the aluminum-doped ZnO layer by adopting the magnetron sputtering method; and preparing a Ni/Al gate electrode by adopting a thermal evaporation method. The flexible stainless steel substrate copper-indium-gallium-selenium film battery and the preparation method thereof disclosed by the invention have the advantages that: a copper-indium-gallium-selenium film with a preferential growth structure (220) is prepared by using the method, so that the problem that the bonding force between a blocking layer and other contact layers is poor is solved, and the preparation process is simplified; and under the condition of AM1.5 illumination, the battery efficiency of the film solar battery is more than 11.0 percent, and the film solar battery plays an important promotion role when applied to the field of solar batteries.

The invention relates to a preparation method of hydroxyapatite nanosheets, which comprises the following step: by using shell powder or egg shells as a calcium source, ammonium phosphate as a phosphorus source and water as a solvent, reacting at 30-70 DEG C to obtain the hydroxyapatite nanosheets. According to the method, the reaction occurs at lower temperature, the prepared shell calcium carbonate crystal grains have favorable crystallinity and obvious oriented preferential growth shape, are sheet-shaped, and have low solubility in the water solution. In the reaction process, calcium carbonate crystal grain dissolution, hydroxyapatite recrystallization and hydroxyapatite grain growth are performed, the calcium carbonate sheet-like crystal grains gradually grow into the hydroxyapatite nanosheets. The method has simple requirements for reactors, and can perform production only by using a glass container, a stirrer, a thermostatic water bath box and other low-temperature reactors; and the production process is easy to operate and does not need any high-temperature high-pressure apparatus, thereby effectively lowering the production cost of hydroxyapatite.

In a deposition method of forming a buildup on a single crystal or directionally solidified crystal parent material, metal deposition is performed from an extension in a preferential growth orientation of parent material crystals while forcedly cooling a portion of the parent material somewhat below a processed surface and beforehand giving a temperature gradient to the parent material so that a maximum temperature gradient is oriented along the preferential growth orientation of parent material crystals.

A disclosed method for preparing a zirconium boride powder with rod-like morphology comprises: based on the boron-thermal/carbon-thermal reduction reaction, taking zirconium dioxide, boron carbide and graphite as raw materials, so as to prepare a mixed powder; employing a pressure of 20-100 Kg/cm<2>, compacting the uniformly mixed powder into a blank body; and performing heat treatment on the blank body with the vacuum degree lower than 10 Pa or in the inert atmosphere. By controlling the blank body forming pressure, under the condition that no auxiliary agents are added, the method employs the boron-thermal/carbon-thermal reduction reaction, and helps to realize preferential growth of crystal grains in a specific direction and to synthesize the ZrB2 high-purity powder with the rod-like morphology; also in the prepared powder, the content of ZrB2 particles with the rod-like morphology is larger than 90 wt%, the length-diameter ratio of the rod-like particles is 3-15, the average particle size is 1.5-10 mu m, the purity is high, and the oxygen content is low; and the preparation technology is simple and strong in controllability, no special equipment is needed, and large-scale production is easily realized.

The invention discloses a three-dimensional hollow titanium dioxide assembled from (001) surfaces, and a preparation method and application thereof. The three-dimensional hollow titanium dioxide can be applied to the field of manufacturing of positive electrode materials of lithium batteries. According to the invention, a hydro-thermal method is employed for preparation of titanium dioxide, and under the co-action of hydrofluoric acid and hydrogen peroxide, the hydrolysis process of a reaction intermediate peroxotitanic acid is effectively regulated and controlled. The formation process of a hollow structure is related to an Ostwald ripening mechanism, fluoride ions promote preferential growth of a crystal along [001] direction, and finally, the three-dimensional hollow product is formed. The method has the advantages of low cost, simple and controllable process, mild reaction, obtainment of the pure product and a high exposure rate of the (001) surfaces; and the titanium dioxide material prepared by using the method has the high-exposure (001) surfaces, is of a hollow micro-nano structure, can be applied to preparation of positive pole pieces of the lithium battery, shortens a diffusion path of lithium ions, facilitates intercalation/deintercalation behavior of lithium ions and alleviates volume expansion of the material during charging and discharging, and thus, the lithium battery has improved charging and discharging efficiency and prolonged cycle life.

Methods for producing silicon carbide crystals, seed crystal holders and seed crystal for use in producing silicon carbide crystals and silicon carbide crystals are provided. Silicon carbide crystals are produced by forcing nucleation sites of a silicon carbide seed crystal to a predefined pattern and growing silicon carbide utilizing physical vapor transport (PVT) so as to provide selective preferential growth of silicon carbide corresponding to the predefined pattern. Seed holders and seed crystals are provided for such methods. Silicon carbide crystals having regions of higher and lower defect density are also provided.

A method of making a semi-polar semiconductor template comprises providing a semi-polar semiconductor wafer; etching the semiconductor wafer to form a regular semiconductor structure comprising a plurality of semiconductor regions (260) with a plurality of gaps between the regions, each of the regions (260) having a sidewall facing a respective one of the gaps, and growing semiconductor material over the semiconductor structure. The semiconductor material has a preferential growth direction (c) in which growth proceeds most rapidly from each of the sidewalls, and each of the sidewalls has at least a part which faces a vertical centre line of the respective one of the gaps so that growth in the preferential direction from said part extends towards said vertical centre line.

The invention relates to a method for controlling film orientation in a vacuum evaporation film making process, belonging to the technical field of vacuum evaporation deposited film process. The method is characterized in that, based on a traditional vacuum evaporation deposit device which is commonly used, an intense magnetic field generation device is additionally arranged outside the vacuum evaporation deposit device, and the strength of the magnetic field of the vacuum evaporation deposit device is required to be larger than 4T (Tesla), and different orientation magnetic energy differences of the magnetic field on metal films cause preferential growth of crystal orientation, thereby achieving the aim of controlling the film orientation through adjusting the strength of the magnetic field.

The invention discloses a preparation method and device of an indium arsenide thin film material and belongs to the technical field of semiconductor manufacturing. The method comprises the steps of ultrasonically cleaning a single-side polished mono-crystalline Si substrate and drying, and then feeding the dried mono-crystalline Si substrate into a vacuum chamber for heating and dehydrogenation; heating an arsenic simple substance for volatilization, and driving As air to flow through the surface of the mono-crystalline Si substrate to form an Si-As bond; activating the surface of the mono-crystalline Si substrate, and then growing a buffer layer at a low temperature; growing an indium arsenide thin film on the surface of the mono-crystalline Si substrate; and carrying out furnace cooling to a room temperature, thereby obtaining the indium arsenide thin film material. The method is low in demands on instrument and equipment, low in cost, easy to operate and relatively good in repeatability; and the obtained indium arsenide thin film is uniform and smooth in appearance and surface, preferential growth along (111) orientation is achieved, the thickness is 4.83 microns and the crystal quality is good.