86results about How to "Small lattice mismatch" patented technology

The invention discloses a method for growing a single-layer graphene thin film by virtue of low-temperature chemical vapor deposition, and belongs to the technical field of two-dimensional thin film material preparation. The preparation method comprises the following steps: (1) preparing an alloy substrate; (2) performing leveling treatment on the alloy substrate; (3) performing annealing treatment on the alloy substrate under a protective atmosphere; and (4) depositing graphene by using a chemical vapor deposition process, and cooling to room temperature to obtain the alloy substrate with a grown single-layer graphene thin film, wherein conditions of the chemical vapor deposition process are as follows: the temperature is 200-800 DEG C, the time is 5-180min, and a carbon source is a gas phase carbon source, a liquid phase carbon source or a solid phase carbon source. The method disclosed by the invention has the advantages that the method is simple, convenient and fast, also is low in cost, and ensures that uniform and single-layer high-quality graphene can be prepared at relatively low temperature; and the method has universality, is simple and mild in condition, uniform in product distribution and good in repeatability, is suitable for industrial production, and is particularly suitable for controllable preparation of single-layer or few-layer graphene.

The invention relates to a preparation method of a high-temperature superconducting thin film. The method specifically comprises steps as follows: providing an SrTiO3 substrate and placing the SrTiO3 substrate in a super-high vacuum system, growing an FeSe monocrystal layer on the surface of the SrTiO3 substrate by adopting a molecular beam epitaxy growing technology, and growing a protective layer with a layered crystal structure by adopting the molecular beam epitaxy growing technology and covering the surface of the FeSe monocrystal layer with the protective layer. By means of the method, the high-quality and ultrathin high-temperature superconducting thin film can be prepared, the starting temperature of superconducting transition of the thin film is above 54K, and the critical current density is higher than 106A/cm<2> when the starting temperature of superconducting transition of the thin film is 12K.

The present invention relates to oxides on suitable substrates, as converted from nitride precursors. A composition comprising a solid solution of zirconium nitride and yttrium nitride (YZN) represented by the formula (ZrxY1-x)N where x is a value from 0.1 to 0.9 is also disclosed.

The invention provides an inverted-structure CdTe nanocrystalline heterojunction high-efficiency solar cell processed by a solution method, and a preparation method of the solar cell. The solar cell is formed by sequentially overlapping a glass substrate, a cathode, a cathode interface layer, an n-type layer, a photoactive layer and an anode together from bottom up, wherein the thickness of the photoactive layer is 100-700 nm; the photoactive layer consists of one or more CdTe nanocrystalline layers; and the n-type layer is a CdSe film. According to the invention, energy conversion rate of the CdTe- CdSe full-inorganic nanocrystalline heterojunction solar cell is greatly increased; open-circuit voltage and a fill factor of the solar cell are increased; and the service life of the solar cell is greatly prolonged. The method is simple in preparation technology; the main process can be completed by solution processing in a common fuming cupboard; comparatively low temperature heat treatment is employed and the preparation cost is greatly lowered.

The invention discloses a non-polar GaN thin film grown on a LiGaO2 substrate. The non-polar GaN thin film comprises a non-polar m-surface GaN buffer layer and a non-polar m-surface GaN layer, wherein the non-polar m-surface GaN buffer layer is grown on the LiGaO2 substrate, and the non-polar m-surface GaN layer is grown on the non-polar m-surface GaN buffer layer; the non-polar m-surface GaN buffer layer is a GaN film layer growing when the temperature of the LiGaO2 substrate is 220-350 DEG C; and the non-polar m-surface GaN layer is a GaN film layer growing when the temperature of the LiGaO2 substrate is 600-750 DEG C. The invention further discloses a manufacturing method and an application of the non-polar GaN thin film. Compared with the prior art, the non-polar GaN thin film disclosed by the invention has the advantages of simple growth process and low manufacturing cost; and in addition, the manufactured non-polar GaN thin film has low defect density and good crystallization quality.

The invention relates to a gallium nitride-based bismuth ferrite ferroelectric thin film and a preparation method thereof. The gallium nitride-based bismuth ferrite ferroelectric thin film comprises a TiO<2> buffer layer, a strontium lanthanum manganate buffer layer and a bismuth ferrite ferroelectric thin film which are formed on a gallium nitride semiconductor thin film substrate in sequence through a pulse laser deposition technology. The gallium nitride-based bismuth ferrite ferroelectric thin film and the preparation method thereof have the following beneficial effects: the LSMO/TiO<2> dual buffer layers are adopted, so that the lattice mismatching degree between bismuth ferrite and gallium nitride is reduced; the epitaxial growth of the bismuth ferrite ferroelectric thin film on the gallium nitride semiconductor thin film is realized; the (111) single-oriented bismuth ferrite thin film is obtained; and the epitaxial integration of the bismuth ferrite ferroelectric thin film and the gallium nitride semiconductor is realized.

The present invention relates to oxides on suitable substrates, as converted from nitride precursors.

The invention discloses a blue-green light-emitting quantum dot and a preparation method thereof. The blue-green light-emitting quantum dot comprises a ZnnCd1-nSmSe1-m core and a shell coating the ZnnCd1-nSmSe1-m core. In the ZnnCd1-nSmSe1-m core, n is greater than 0 and is less than 1, m is greater than or equal to 0 and less than or equal to 1 and the shell is a ZnS shell, a ZnSe shell or a CdS shell. The blue-green light-emitting quantum dot comprises the ZnnCd1-nX quantum dot as a core and the epitaxial growth ZnS shell, ZnSe shell or CdS shell so that a quantum dot structure is simplified. Through a core-shell structure, a lattice mismatch degree of the core-shell structure is reduced. The blue-green light-emitting quantum dot formed in a wavelength scope of 450-550nm so that the QD-LED maximum brightness of the blue-green light-emitting quantum dot is 4700cd/m<2> or more.

The invention discloses an LED epitaxial wafer growing on an Ag substrate. The LED epitaxial wafer growing on the Ag substrate comprises the Ag substrate, an AlN buffer layer, a U-GaN film layer, an N-GaN film layer, an InGaN/GaN multi-quantum-well layer and a P-GaN film. The AlN buffer layer, the U-GaN film layer, the N-GaN film layer, the InGaN/GaN multi-quantum-well layer and the P-GaN film sequentially grow on the Ag substrate. By the adoption of the low-temperature growth technology, a GaN film grows on the novel metal Ag substrate in an epitaxial mode, so that the LED epitaxial wafer with the high quality is obtained; by the adoption of the metal Ag substrate, the growth technology is simple, the price is low, and the manufacturing cost of a device can be reduced to a great extent; by the selection of the proper crystal orientation, the GaN epitaxial film with the high quality is obtained from the Ag substrate (111) and the efficiency of nitride devices such as a photoelectric detector can be improved to a great extent.

The invention relates to the technical field of yttrium barium copper oxide coating conductors, in particular to a high-performance REBCO multilayer film, application and a preparation method for the high-performance REBCO multilayer film. The high-performance REBCO multilayer film is composed of a REBCO thin film layer and an STO interlayer. The invention further relates to the application of the high-performance REBCO multilayer film during preparing of a high-temperature superconductive belt material and relates to the preparation method for the high-performance REBCO multilayer film. The preparation method comprises the following steps that an IBAD-MgO base belt plated with an isolated layer is taken, and the high-performance REBCO multilayer film is prepared through a multi-target multi-channel pulse laser method. The prepared high-performance REBCO multilayer film prepared has a pure C-axis orientation, a smooth compact surface and a high critical current density, and the critical current density reaches up to 5 MA/cm<2>. The REBCO multilayer film has high critical current under a self field or a magnetic field, has the high binding force, can meet the application requirements for a superconducting cable and the like and is suitable for industrialization production.

The invention belongs to the technical field of photocatalytic thin film manufacturing, and provides a photocatalytic thin film on a foam metal-graphene composite substrate and a preparation method. Concretely, the preparation method comprises the steps of taking a foam metal-graphene composite material as a substrate, firstly using an electron cyclotron resonance-plasma enhancing metal organic matter CVD (chemical vapor deposition) method to successively perform nitrogen treatment of the foam metal-graphene composite substrate, preparation of a GaxZnl-xNxO1-x buffer layer and preparation of an n-type GaxZn1-xNxO1-x layer, then using a thermal polymerization method to prepare a p-type g-C3N4 layer, and finally using a magnetron sputtering method to prepare a precious metal nanometer granular layer. The prepared photocatalytic thin film has a very good visible light photocatalysis effect, can be used for photolyzing water to produce hydrogen, degrading organic pollutant in waste water,removing harmful gas and purifying air, and has a broad application prospect.

The invention discloses an LED epitaxial wafer growing on a metal Al substrate. The LED epitaxial wafer comprises the metal Al substrate, an Al2O3 protecting layer growing on the metal Al substrate with a metal Al substrate crystal face (111) as an epitaxial face, a U-GaN thin film layer, an N-GaN thin film layer, an InGaN/GaN multi-quantum-well layer and a p-type GaN thin film. The epitaxy orientation relationship of the U-GaN thin film layer, the N-GaN thin film layer, the InGaN/GaN multi-quantum-well layer and the p-type GaN thin film is GaN (0001)//Al2O3 (0001)//Al (111), and the U-GaN thin film layer, the N-GaN thin film layer, the InGaN/GaN multi-quantum-well layer and the p-type GaN thin film grow on the Al2O3 protecting layer from bottom to top. By selecting proper crystal orientation, a high-quality GaN epitaxial thin film is obtained on the Al (111) substrate, and accordingly the light emitting efficiency of an LED is improved.

The invention discloses blue-green luminescent quantum dots and a preparation method therefor. Each quantum dot comprises a CdS(n)Se(1-n) core, a CdS buffer layer, a Zn(0.5)Cd(0.5)X buffer layer and a ZnS shell. In the CdS(n)Se(1-n) core, n is greater than 0 and is smaller than 1. The CdS buffer layer coats the outer periphery of the CdS(n)Se(1-n) core, the Zn(0.5)Cd(0.5)X buffer layer coats the outer periphery of the CdS buffer layer, and X is S or Se; and the ZnS shell coats the outer periphery of the Zn(0.5)Cd(0.5)X buffer layer. According to the blue-green luminescent quantum dots, through introducing the CdS buffer layer and the Zn(0.5)Cd(0.5)X buffer layer sequentially, the lattice mismatch degree of a core-shell structure is lowered, and the blue-green luminescent quantum dots in the wavelength range of 450nm to 550nm are formed, so that the maximum brightness of an QD-LED using the blue-green luminescent quantum dots can reach 4,700cd/m<2> or more.

The invention discloses a GaN thin film growing on a metal Al substrate and a preparing method and application thereof. The GaN thin film growing on the metal Al substrate comprises the Al substrate, an Al2O3 protecting layer growing on an epitaxy face which is a face (111) of the Al substrate and a GaN thin film layer growing on the Al2O3 protecting layer in an epitaxial mode. The crystal epitaxial orientation relationship of the Al2O3 protecting layer and the GaN thin film layer is GaN (0001)//Al2O3 (0001)//Al (111). Proper crystal orientation is selected, so that a high-quality GaN epitaxial thin film is obtained on the Al (111) substrate and is used for improving nitride device efficiency. The GaN thin film is mainly used as dielectric layer thin films of a sound wave resonator, a logic circuit, a light-emitting diode, an optoelectronic thin film device, a solar cell, a photodiode, a photoelectric detector, a laser device and the like.

The invention discloses a method for quickly preparing a simplified single CeO2 buffering layer on an IBAD (Ion Beam Assisted Deposition)-MgO base band by using a PLD (Pulsed Laser Deposition) technology. By using the method disclosed by the invention, an excellent crystallographic orientation can be acquired by not using an epitaxial homogeny MgO layer in a structure of a buffering layer with single orientation and high texture degree essential to an epitaxial growth YBCO (Yttrium Barium Copper Oxide) superconducting layer; and the simplification and low cost of a manufacturing process of the buffering layer in a preparation process of a YBCO superconducting band material are realized.

The invention is applicable to the technical field of semiconductor and provides a method for preparing single-layer graphene on the surface of ultranano diamond. The method comprises preprocessing anultranano diamond film to eliminate surface impurities and surface stress; forming a metal layer on the nucleation surface of the preprocessed ultranano diamond film, wherein the metal layer is composed of a nickel layer and a copper layer on the upper surface of the nickel layer or is a copper-nickel alloy layer; performing high-temperature annealing treatment on the ultranano diamond film withthe grown metal layer to self-organize the single-layer graphene. The method for preparing the single-layer graphene on the surface of the ultranano diamond saves a second transfer process by directlygrowing the single-layer graphene on the ultranano diamond film, thereby effectively avoiding introduced impurities and lattice imperfection during second transfer processes; meanwhile, the grown single-layer graphene is small in lattice mismatch and surface change.

The invention relates to a magnetic tunnel junction with a quantum effect, and a spin diode and a spin transistor comprising the magnetic tunnel junction. The magnetic tunnel junction comprises a first reference layer, a first barrier layer, a free layer, and a second barrier layer, wherein the first reference layer is formed by a magnetic conductive material and has a fixed magnetizing direction; the first barrier layer is arranged on the first reference layer and formed by an insulating material; the free layer is arranged on the first barrier layer, and formed by a magnetic conductive material, and the magnetizing direction of the free layer can respond to an outer magnetic field to be freely changed; and the second barrier layer is arranged on the free layer and formed by an insulating material, wherein the insulating materials of the first barrier layer and the second barrier layer both comprise a spinel-like crystal structure.

The invention discloses a doped GaN film grown on a LiGaO2 substrate. The doped GaN film comprises the LiGaO2 substrate, a non-polar m-surface GaN buffer layer, a non-polar m-surface GaN epitaxial layer and a non-polar doped GaN film, wherein the non-polar GaN film is a non-polar p-type GaN film or a non-polar n-type GaN film. The invention also discloses a preparation method of the non-polar doped GaN film. Compared with the prior art, the non-polar doped GaN film has the advantages of simple growth process and low preparation cost, and the prepared non-polar doped GaN film is low in defect density, good in crystallization quality and high in electrical property.