115results about How to "Reduce lattice mismatch" patented technology

he invention relates to a novel SINP silicone blue-violet battery and a preparation method thereof. The invention uses shallow junctions formed from thermally diffused phosphorus, an ultra-thin SiO2 layer formed by low-temperature thermal oxidization and an ITO dereflection/collection electrode film formed by RF magnetron sputtering to prepares a novel ITO/SiO2/np blue-violet reinforced SINP silicone photo-battery. Preparation method of the invention is to take a silicon single crystal flake which is P type, and has crystallographic orientation of 100, electric resistivity of 2 2omega.cm and thickness of 220mu m, as a substrate. The substrate is cleaned and is etched by routine chemistry, and then is thermally diffused by POC3 liquid source to form n regions (the invention prepares two pieces of novel SINP photo-batteries, one being routine SINP photo-battery having emitting region square resistance of 10 Omega/square and junction depth of 1 Mu m, and the other one being SINP silicone blue-violet battery having emitting region square resistance of 37 Omega/square and junction depth of 0.4 Mu m). Removing the phosphorosilicate glass (HF:H2O=1:10) at front face; steaming Al at back of the silicon chip; thermally oxidizing the silicon chip at 400 to 500 DEG C and condition of V2:O2=4:1 for 15 to 30min to generate a layer of 15 to 20 ultra-thin SiO2 layer, and at the same time alloying the Al at the back. Then RF magnetron sputtering the ITO dereflection/collection electrode film (ITO film is also deposited on the glass to study electrooptical characteristic thereof) having high transmittance and high conductivity, and sputtering a Cu gate electrode by metal mask direct-current magnetron. Finally, cutting the outer edge part of the battery by a diamond excircle downward cutting/a dicing saw so as to prevent short circuit of the edge of the photo-battery.

The invention provides core-shell alloy quantum dots and a preparation method of the core-shell alloy quantum dots. The preparation method comprises the following steps: mixing a nucleation cation source, a nucleation anion source and a hydrocarbon organic solvent, and carrying out heat preservation at the nucleation temperature of 220-280 DEG C, thereby obtaining quantum dot nuclear bodies; mixing the obtained quantum dot nuclear bodies with a crusting cation source, a crusting anion source and a hydrocarbon organic solvent at the crusting temperature of 300 to 318 DEG C to obtain core-shellalloy quantum dots. By adopting the preparation method of the core-shell alloy quantum dots, quantum dot crystal nuclei are synthesized at lower temperature and a shell layer is grown at higher temperature later to obtain the core-shell alloy quantum dots with high quantum yield and good stability.

The invention discloses a gallium nitride light emitting diode and a preparation method thereof and belongs to the field of light emitting diodes. The method comprises the following steps: providing a foreign substrate, and depositing a first buffering layer on the foreign substrate by taking a first temperature as a growing temperature; depositing a second buffering layer on the first buffering layer and enabling the second buffering layer to grow at a second temperature from the time of beginning to grow to a first pre-set time, wherein the first temperature is lower than the second temperature and the differential value range of the first temperature and the second temperature is 410-460 DEG C; depositing a third buffering layer on the second buffering layer by taking a third temperature as the growing temperature, wherein the second temperature is lower than the third temperature; and sequentially depositing an N type contact layer, a light-emitting layer, an electronic barrier layer and a P type contact layer on the third buffering layer to finish the preparation of the gallium nitride light emitting diode. The light emitting diode is prepared by adopting the method. The growing starting temperature of the second buffering layer is between the growing temperature of the first buffering layer and the growing temperature of the third buffering layer and the second buffering layer has the buffering and protection effects on the third buffering layer.

The invention provides a preparation method of a gallium nitride film layer and a substrate. The preparation method of the gallium nitride film layer comprises the following steps: obtaining and cleaning an indirect substrate; forming a graphene film on the surface of the indirect substrate; and forming a gallium nitride film layer on the surface of the graphene film. The preparation method of the gallium nitride film layer can effectively reduce the dislocation density of the gallium nitride film layer in a process of growth, thereby improving performance of the gallium nitride film layer.

The present invention relates to a method for growing a non-polar m-plane epitaxial layer on a single crystal oxide substrate, which comprises the following steps: providing a single crystal oxide with a perovskite structure; using a plane of the single crystal oxide as a substrate; and forming an m-plane epitaxial layer of wurtzite semiconductors on the plane of the single crystal oxide by a vapor deposition process. The present invention also provides an epitaxial layer having an m-plane obtained according to the aforementioned method.

The invention relates to a preparation method for a GaAs/Ge/GaAs heterostructure SPiN diode string used for a sleeve antenna. The preparation method comprises the steps of (a), selecting a GeOI substrate; (b), etching a top layer Ge layer of the GeOI substrate to form a first trench and a second trench in the top layer Ge layer; (c), depositing a GaAs material in the first trench and the second trench; (d), performing P type ion implantation on the GaAs material in the first trench by adopting an ion implantation process to form a P type active region, and performing N type ion implantation on the GaAs material in the second trench to form an N type active region; and (e), forming lead holes in the surfaces of the P type active region and the N type active region and performing metal sputtering to form the GaAs/Ge/GaAs heterostructure SPiN diode. According to the embodiments, the high-performance Ge-based SPiN diode string, which is applicable to formation of a solid-state plasma antenna, can be prepared and provided through a deep trench isolation technology and the ion implantation process.

The invention discloses a gallium-nitride-based light emitting diode epitaxial wafer and a manufacturing method thereof, belonging to the technical field of semiconductors. The gallium-nitride-based light emitting diode epitaxial wafer comprises a superlattice buffer layer, wherein the superlattice buffer layer is of a superlattice structure comprising N periods, and the superlattice structure ofeach period comprises a first sublayer, a second sublayer and a third sublayer which are laminated on a substrate. Through doping Al into the first sub-layer, the lattice mismatch between the substrate and a GaN layer can be alleviated, the defect density can be reduced, and the crystal quality of the entire epitaxial layer can be improved, thereby improving the anti-static capability of an LED. Through doping Mg into the second sublayer, a transition between the first sublayer and the second sublayer can be achieved. Through doping In into the third sublayer, the lattice constant of the thirdsublayer can be increased, thereby accelerating a stress release speed of an N-type layer, reducing the stress polarization effect of a multi-quantum well layer, and increasing the luminous efficiency of the LED.

The invention discloses a laser diode based on a gallium nitride single crystal substrate and a preparation method of the laser diode. The laser diode comprises the GaN single-crystal substrate, an n-type GaN layer, an n-type limiting layer, a lower waveguide layer, a composite quantum well active region, an electron blocking layer, an upper waveguide layer, a p-type limiting layer and a p-type GaN layer which are sequentially stacked from bottom to top. According to the invention, the high-quantum efficiency stress regulation and control active region structure, the novel optical waveguide layer structure and the novel limiting layer structure of the gallium nitride-based laser diode are designed and optimized; the laser diode is prepared on the low-dislocation-density GaN single-crystalsubstrate; the technical difficulty of epitaxial preparation of a GaN-based laser is eliminated; and a GaN-based laser with high reliability and high quantum efficiency can be obtained.

A processing method for improving a threshold voltage of a thin film transistor (TFT) device is applied before a gate insulation layer formed on a poly-silicon channel film layer and comprises the following steps of performing hydrofluoric acid cleaning operation on the poly-silicon channel film layer with hydrofluoric acid; performing protection atmosphere thermal processing operation on the poly-silicon channel film layer subjected to hydrofluoric acid cleaning operation; performing first-time ionization operation on hydrogen in a vacuum chamber to form first plasma, and performing first-time plasma cleaning operation with the first plasma; and performing second-time ionization operation on nitrogen monoxide in the vacuum chamber to form second plasma, and performing second-time plasma cleaning operation with the second plasma. By the processing method for improving the threshold voltage of the TFT device, an interface state between the poly-silicon channel film layer and the gate insulation layer can be improved, the threshold voltage of the TFT device can be reduced, so that the threshold voltage of the TFT device can be improved.

Provided are: a gallium oxide single crystal composite, which can provide, for example, upon a crystal growth of a nitride semiconductor, a high-quality cubic crystal in which mixing of a hexagonal crystal is reduced to thereby realize dominant growth of a cubic crystal over hexagonal crystal, and which can be utilized as a substrate particularly suitable for epitaxial growth of cubic GaN; a process for producing the same; and a process for producing a nitride semiconductor film. The gallium oxide single crystal composite has a gallium nitride layer formed of cubic gallium nitride on a surface of the gallium oxide single crystal; the process for producing the gallium oxide single crystal composite includes subjecting the surface of gallium oxide single crystal to nitriding treatment using ECR plasma or RF plasma to form the gallium nitride layer formed of cubic gallium nitride on the surface of the gallium oxide single crystal; and further, the process for producing the nitride semiconductor film includes growing the nitride semiconductor film on the surface of the gallium oxide single crystal composite by an RF-MBE method.

The invention discloses a quantum dot and a preparation method thereof, wherein the quantum dot comprises a quantum dot core, a metal layer covering the quantum dot core, and a semiconductor shell layer covering the metal layer, and the metal element in the metal layer is one or a plurality of elements selected from Zn, Hg, Al, Ga and In. According to the present invention, the metal layer can bebonded to the quantum dot core by using the ligand on the surface of the quantum dot core as the linker so as to promote the surface activation of the quantum dot core, such that the further growth reaction of the semiconductor shell layer outside the quantum dot can be easily performed; and through the crystal structure formed by bonding the metal atom in the metal layer and the quantum dot core,the surface of the quantum dot core can be effectively passivated, the surface defect can be reduced, and the lattice mismatch between the core and the shell can be reduced, such that the light emitting efficiency and the size uniformity of the quantum dot material can be enhanced.

The invention discloses a ZnO MQW (Multi-Quantum well) luminous diode. A ZnO buffer layer, an n-type ZnO layer, an n-type Zn1-xMgxO confinement layer, a Zn1-xMgxO/ Zn1-yCdyO MQW layer formed by the alternative deposition of Zn1-xMgxO and Zn1-yCdyO, a Na-doped p-type Zn1-xMgxO film, a Na-doped p type ZnO film layer and a second electrode are sequentially arranged from upper to lower on a substrate. A first electrode and the n-type Zn1-xMgxO confinement layer are deposited on the n-type ZnO layer in parallel. The ZnO MQW (Multi-Quantum well) luminous diode is of good crystallization quality, good optical performance, good electric performance and high luminous efficiency.

The invention discloses a blue-light LED (Light-Emitting Diode) epitaxial structure having an asymmetrical barrier layer, and relates to the technical field of epitaxy of light-emitting diodes. The structure comprises a sapphire substrate, an AlN (Aluminum Nitride) buffer layer, a U type GaN (Gallium Nitride) layer, an N type GaN layer, an active region, an electron blocking layer and a P type GaN layer in sequence from bottom to top, wherein the active region comprises a trap layer and a barrier layer; the growing period number of the active region is 3m; the active region comprises three parts, and each part grows for m periods; the barrier layer consists of an AlxGa1-xN layer, an AlyIn1-yN layer and an InzGa1-zn layer; and m is greater than or equal to 1 and smaller than or equal to 5. Compared with the prior art, the blue-light LED epitaxial structure has the advantages that an overflow phenomenon can be retarded, and bending of an energy band is reduced; and the internal quantum efficiency is increased, so that the light emitting efficiency is increased effectively.

The invention discloses a quantum dot and a preparation method thereof. The quantum dot comprises a quantum dot core, a first metal layer covering the quantum dot core, a first semiconductor shell layer covering the first metal layer, a second metal layer covering the first semiconductor shell layer, and a second semiconductor shell layer covering the second metal layer, wherein the metal elementsin the first metal layer and the second metal layer are independently one or a plurality of elements selected from Zn, Hg, Al, Ga and In. According to the present invention, the metal layer can be bonded to the quantum dot core by using the ligand on the surface of the quantum dot core as the linker so as to promote the surface activation of the quantum dot core, such that the further growth reaction of the semiconductor shell layer outside the quantum dot can be easily performed; and through the crystal structure formed by bonding the metal atom in the metal layer and the quantum dot core, the surface of the quantum dot core can be effectively passivated, the surface defect can be reduced, and the lattice mismatch between the core and the shell can be reduced, such that the light emitting efficiency and the size uniformity of the quantum dot material can be enhanced.

The invention discloses a P-type cap layer enhanced HEMT (High Electron Mobility Transistor) device and a preparation method thereof, and belongs to the technical field of microelectronics. The devicecomprise a substrate, a low-temperature nucleating layer, a buffer layer, a high-resistance layer, a channel layer, a barrier layer, an insertion layer and a P-GaN cap layer which are sequentially stacked from bottom to top. The invention provides a new structure and a new growth method, so that the epitaxial preparation of the enhanced HEMT device is realized, and the stability of the performance of the enhanced HEMT device is ensured.

The invention relates to a Ga2O3-based transparent conducting thin film and a preparation method thereof. The transparent conducting thin film is an n-type thin film with high concentration obtained by mixing Si and Ta elements into a Ga2O3 thin film. A thin film deposition method is adopted in the Ga2O3-based transparent conducting thin film is laser pulse deposition method, and the Ga2O3-based transparent conducting thin film is deposited on the substrate surface after a laser beam bombards Ca2O3-based adulteration mixed target. The obtained Ga2O3-based transparent conducting thin film has higher carrier concentration (>4 *10<19> cm<-3>) and good electrical conductivity, has high light-admitting quality (>82%) in deep ultra violet to a visible region, is suitable for as a window layer and an electrode layer material of ultra violet luminescent devices (such as LED, LD), solar-blind detector and other devices, and has a good application prospect.

The invention discloses a light emitting diode epitaxial wafer and a manufacturing method thereof, and belongs to the technical field of semiconductors. A multi-quantum-well layer of the light emitting diode epitaxial wafer is of a multi-cycle superlattice structure, wherein each superlattice structure comprises an InGaN quantum well layer, and a transition layer and a GaN quantum barrier layer which are sequentially stacked on the InGaN quantum well layer; the transition layer comprises a first sub-layer and a second sub-layer arranged on the first sub-layer, wherein the first sub-layer is anAlInN layer, and the second sub-layer is an AlGaN layer. The AlInN material is relatively matched with the InGaN material lattice, the AlGaN material is relatively matched with the crystal lattice ofthe GaN material, and the AlInN material is relatively matched with the lattice of the GaN material, so that the lattice mismatch between the InGaN quantum well layer and the GaN quantum barrier layer can be reduced by arranging the first sub-layer and the second sub-layer, and therefore the defects are reduced, and the radiation composite luminescence efficiency of electrons and holes in the multi-quantum well layer is improved.

The invention provides an ultraviolet light-emitting diode (LED) epitaxial structure. The epitaxial structure sequentially comprises an AlN Buffer layer, a high-temperature UGaN layer, a composite N-type GaN layer, a multi-quantum well (MQW) structure, an active region light-emitting quantum-well layer, an electron blocking layer (EBL) and a P-type GaN layer from bottom to top, wherein the active region light-emitting quantum-well layer comprises n layers of In<x>Ga<1-x>N/Al<y>Ga<1-y>N multi-quantum wells, each layer of In<x>Ga<1-x>N/Al<y>Ga<1-y>N multi-quantum well comprises a main barrier and a movable barrier, the movable barrier is embedded into the main barrier, the main barrier comprises Al<y>Ga<1-y>N, the height of the main barrier is gradiently increased with the increase of Al constituent, the movable barrier comprises GaN, and the thickness of each layer of movable barrier is 1-20 nanometers. By the ultraviolet LED epitaxial structure and a growth method thereof, the stress in the quantum wells is reduced, the hole injection efficiency is improved, electrons of an active layer is prevented from overflowing, and the carrier recombination probability and the internal quantum efficiency of an ultraviolet LED are improved.

The invention discloses an InAs/AlSb high electron mobility transistor (HEMT) epitaxial structure and a fabrication method thereof. The InAs/AlSb HEMT epitaxial structure disclosed by the invention comprises a substrate, a buffer layer, a AlAs<x>Sb<1-x> lower barrier layer, an InAs channel layer, a AlSb isolation layer, an InAs doping layer, a AlAs<x>Sb<1-x> upper barrier layer, an InAlAs hole barrier layer and an InAs cap layer from bottom to top, wherein the buffer layer employs Si, the AlAs<x>Sb<1-x> lower barrier layer is a AlAs<x>Sb<1-x> barrier layer with a stepped variable constituent mode, and the AlAs<x>Sb<1-x> upper barrier layer is a AlAs<x>Sb<1-x> barrier layer with a stepped variable constituent mode. The AlAs<x>Sb<1-x> lower barrier layer and the AlAs<x>Sb<1-x> upper barrier layer are grown by employing a stepped variable constituent method, and the stability and the reliability of a device are effectively improved.

The invention provides nickel-based high-temperature alloy powder and a preparation method for applying the nickel-based high-temperature alloy powder to a hollow turbine blade, and solves the technical problem of cracking in the process of preparing the hollow turbine blade through selective laser melting. The Ni-Cr-Co-Ti-W alloy material comprises the following components in percentage by weight: 25% to 30% of Cr, 17.5% to 19% of Co, 2.5% to 3.0% of Al, 2.3% to 2.5% of Ta, 2.6% to 2.8% of Ti, 1.7% to 2.1% of W, 1.5% to 2.5% of Re, 0.1% to 0.15% of C, 0.8% to 1% of Cb, 0.2% to 0.3% of Zr, 0.005% to 0.01% of B, 0.5% to 0.7% of V and the balance of Ni. The method can be widely applied to the technical field of additive manufacturing.

Embodiments disclose a light emitting device including a substrate, a buffer layer disposed on an R-plane of the substrate, the buffer layer having a rock salt structured nitride, and a light emitting structure arranged on the buffer layer, the light emitting structure being grown in an a-plane.

The invention discloses a silicon-based micro LED chip and a manufacturing method thereof. The chip comprises a silicon substrate, a plurality of light emitting structures, cutting grooves and an organic insulating layer, wherein the cutting grooves are formed among the light emitting structures. The chip is advantaged in that the silicon substrate is adopted to replace a sapphire substrate, so damage to a gallium nitride material and a micro LED chip caused by N2 generated by decomposition after gallium nitride absorbs laser during laser stripping of the sapphire substrate is avoided, the silicon substrate is removed through a physical grinding and chemical corrosion two-step method, the light emitting structure can be protected against damage while the silicon substrate is effectively removed, and the removal yield and reliability of the substrate are improved.