88results about How to "Improve lattice matching" patented technology

There is provided a light-emitting device including a second electrode which exhibits a stable behavior in a process for manufacturing a light-emitting device or during an operation of a light-emitting device. A light-emitting device includes a first compound semiconductor layer 11 with an n-type conductivity type, an active layer 12 formed on the first compound semiconductor layer 11 and composed of a compound semiconductor, a second compound semiconductor layer 13 with a p-type conductivity type formed on the active layer 12, a first electrode 15 electrically connected to the first compound semiconductor layer 11, and a second electrode 14 formed on the second compound semiconductor layer 13, wherein the second electrode 14 is composed of a titanium oxide, has an electron concentration of 4×10²¹/cm³ or more, and reflects light emitted from the active layer.

The invention discloses an MQW (multiple quantum well)-growth applied GaN (gallium nitride)-based green-light LED (light emitting diode) epitaxial structure, and relates to the technical field of LED epitaxial production, in particular to growth technology of GaN-based green-light LEDs. The MQW-growth applied GaN-based green-light LED epitaxial structure comprises a GaN nucleating layer, a non-mixed GaN layer, a n-type GaN layer, an InGaN (indium gallium nitride)/GaN MQW active layer and a p-type GaN layer which are sequentially grown on a substrate. The InGaN/GaN MQW active layer comprises a GaN barrier layer, an InGaN quantum well layer and a temperature-changing GaN transition layer. A buffering layer shallow well with low In components is grown between the GaN barrier layer and the InGaN quantum well layer of the InGaN/GaN MQW active layer. Stress between a quantum well and a barrier is greatly reduced, and stress difference between the quantum well and the barrier is relieved, so that a polarization electric field in the quantum well is greatly reduced. By the buffering layer shallow well between the barrier and the quantum well, the polarization electric field is reduced, spatial segregation of an electron-hole wave function is relieved, and effective radiative recombination can be improved.

The invention discloses a method and system for forming a Cu-In-Ga-S-Se absorption layer and a cadmium sulfide buffer layer in an antivacuum way. The method comprises the steps of: in specific to a substrate with a back electrode layer under antivacuum, forming a coating layer from mixed slurry on the back electrode layer, primarily drying, compacting the coating layer by using a compacting device, carrying out primary S-Se reaction treatment to form a primary Cu-In-Ga-S-Se layer, thermally treating to improve the lattice matching of the primary Cu-In-Ga-S-Se layer, carrying out miscellaneous-phase removal treatment by using potassium cyanide or bromides to remove miscellaneous-phase cuprous selenide and copper sulphide, carrying out post-stage S-Se reaction treatment to generate a needed post-stage Cu-In-Ga-S-Se absorption layer, and finally, forming a cadmium sulfide buffer layer on the Cu-In-Ga-S-Se absorption layer by using a chemical-tank water bath method.

The principles of the present invention are used to reduce the conduction band offset between chalcogenide emitter and pnictide absorber films. Alternatively stated, the present invention provides strategies to more closely match the electron affinity characteristics between the absorber and emitter components. The resultant photovoltaic devices have the potential to have higher efficiency and higher open circuit voltage. The resistance of the resultant junctions would be lower with reduced current leakage. In illustrative modes of practice, the present invention incorporates one or more tuning agents into the emitter layer in order to adjust the electron affinity characteristics, thereby reducing the conduction band offset between the emitter and the absorber. In the case of an n-type emitter such as ZnS or a tertiary compound such as zinc sulfide selenide (optionally doped with Al) or the like, an exemplary tuning agent is Mg when the absorber is a p-type pnictide material such as zinc phosphide or an alloy of zinc phosphide incorporating at least one additional metal in addition to Zn and optionally at least one non-metal in addition to phosphorus. Consequently, photovolotaic devices incorporating such films would demonstrate improved electronic performance.

The invention provides a light-emitting diode (LED) lighting structure. The LED lighting structure comprises a p type doped region, a n-type doped region and a lighting active region, wherein the p-type doped region is used for injecting into a hole, the n-type doped region is located on the bottom and used for injecting electrons and the lighting active region is located on the n-type doped region. The LED lighting structure is characterized in that the lighting active region comprises at least one InGaN trap layer and at least one InAlGaN barrier layer of a first type quantum well, at least one InGaN trap layer and at least one InAlGaN barrier layer of a second type quantum well and at least one InGaN trap layer and at least one InAlGaN barrier layer of a third type quantum well.

The invention discloses an LED epitaxial structure growth method. The method comprises steps: a sapphire substrate is processed; a low-temperature GaN buffer layer grows on the sapphire substrate, thelow-temperature GaN buffer layer is processed, and an irregular island is formed on the low-temperature GaN buffer layer; an undoped GaN layer grows on the low-temperature GaN buffer layer; a Si-doped N-type GaN layer grows on the undoped GaN layer; a multi-quantum well layer grows on the Si-doped N-type GaN layer; an AlGaN electron blocking layer grows on the multi-quantum well layer; a Mg-dopedP-type GaN layer grows on the AlGaN electron blocking layer; and temperature reduction and cooling are carried out. According to the growth method disclosed in the invention, the light emitting efficiency of the LED can be effectively enhanced, warpage of the epitaxial wafer can be reduced, the qualified rate of the GaN epitaxial wafer is improved, the surface of the epitaxial layer becomes flat,and the appearance is better.

Disclosed is a sintered magnet which is a rare-earth magnet using a less amount of a rare-earth element but having a higher maximum energy product and a higher coercivity. The sintered magnet includes a NdFeB crystal; and an FeCo crystal adjacent to the NdFeB crystal through the medium of a grain boundary. The FeCo crystal includes a core and a periphery and has a cobalt concentration decreasing from the core to the periphery. The FeCo crystal has a difference in cobalt concentration of 2 atomic percent or more between the core and the periphery. In the NdFeB crystal, cobalt and a heavy rare-earth element are unevenly distributed and enriched in the vicinity of the grain boundary.

The invention discloses steel for bucket teeth of construction machinery and a preparation method of the bucket teeth, and relates to the technical field of mechanism manufacturing. The steel for the bucket teeth is prepared from the following substances in percentage by weight: 0.25 to 0.33% of C, 0.30 to 0.80% of Si, 0.80 to 1.20% of Mn, 0.60 to 1.0% of Cr, 0.030 to 0.036% of Re, 0.0005 to 0.0035% of B, 0.20 to 0.40% of nanometer TiN, not greater than 0.030% of S, and not greater than 0.030% of P. With the adoption of the method, the problems of poor impact toughness, easy breaking, small service life, and high production cost which is caused by lots of added precious metals Mo and Ni can be solved.

The invention discloses a preparation method of a porous titanium-substrate-loaded nickel oxide (nickel hydroxide) electrode with an electroconductive ceramic interface. The preparation method includes (1), ball-milling and mixing metal titanium hydride powder and nickel powder to obtain a metal powder mixture;(2), putting a certain amount of the metal powder mixture into a steel die, and performing pressurization to obtain a metal pressed blank; (3), putting the metal pressed blank into a tubular furnace, and controlling sintering atmosphere and temperature time to obtain the porous titanium-substrate-loaded nickel oxide electrode with the electroconductive ceramic interface; (4), washing the surface of the electrode by dilute acid and deionized water; (5), in nickel nitrate, depositing acertain amount of nickel hydroxide on the surface of the electrode according to a cathodic polarization method to obtain the porous titanium-substrate-loaded nickel hydroxide electrode with the electroconductive ceramic interface. The preparation method has the advantages that the porous electroconductive ceramic interface TinO2n-1-Ti*NiOy generated during high-temperature hypoxic sintering is utilized, contact resistance between active substances and a substrate is reduced, and contact strength between the active substances and the substrate is improved.

The invention discloses alloy steel for bucket teeth and a preparation method of the bucket teeth, and relates to the field of mechanical manufacturing. The alloy steel for the bucket teeth comprises the chemical components in percentage by weight: 0.25-0.33 percent of C, 0.30-0.80 percent of Si, 0.85-1.25 percent of Mn, 0.70-1.10 percent of Cr, 0.20-0.35 percent of nanoscale TiN, less than or equal to 0.030 percent of p and less than or equal to 0.030 percent of S. The method comprises the following steps: smelting and casting the materials to obtain castings; and performing heat treatment to obtain the bucket teeth. When the alloy steel is smelted, Ca-Si alloys are added while preliminary deoxidizing is carried out by using ferromanganese and silicon iron at the same time, the nanoscale TiN is added during modification treatment; the bucket teeth castings are subjected to high-temperature solid solution spheroidizing annealing. According to the alloy steel and the preparation method, the problems of high material cost of the bucket teeth, poor impact toughness, easiness for breakage and short service life are solved.

The present invention provides a 795nm quantum well laser based on an AlGaAs/GaInP active region. The epitaxial structure comprises a substrate, a buffer layer, an N-type lower limit layer, a lower waveguide layer, a quantum well layer, an upper waveguide layer, and P-type upper limit layer and an ohmic contact layer from the bottom to the top. The upper waveguide layer and the lower waveguide layer are made of an aluminum-free material gallium indium phosphate, the quantum well layer is made of an aluminum gallium arsenide material, and a wide waveguide semi-aluminum-free active region is formed by the waveguide layers and the quantum well layer. According to the 795nm quantum well laser, the special requirements of a pump laser with the application of a small and simplified self-doubledlaser crystal can be satisfied, at the same time, the influence of the roughness of a growth interface and an episodic field at a cavity surface on the service and reliability of the laser can be reduced effectively by an optimized laser structure.

The invention discloses green quantum dots, a preparation method therefor and an application of the green quantum dots. The green quantum dots have CdSe/ZnSeXS1-X/ZnS structures and comprise CdSe cores, ZnSeXS1-X shells and ZnS shells, wherein peripheries of the CdSe cores are coated with the ZnSeXS1-X shells, X is greater than 0 and is not greater than 1, and peripheries of the ZnSeXS1-X shells are coated with the ZnS shells. The green quantum dots have the characteristics of quantum efficiency higher than 90%, half-peak breadth between 20nm and 26nm, monodispersity and the like; and QLED devices based on the green quantum dots have the advantages of high external quantum efficiency, long device lifetime and the like.

The invention discloses a manufacturing method of a light-emitting diode epitaxial wafer, and belongs to the technical field of semiconductors. The manufacturing method comprises the following steps:providing a substrate; putting the substrate into PVD equipment, and depositing an AlN buffer layer on the substrate; putting the substrate deposited with the AlN buffer layer into an alkaline solution, and reacting the alkaline solution with the AlN buffer layer to ensure that the surface of the AlN buffer layer is an Al polar surface; putting the substrate deposited with the AlN buffer layer into MOCVD equipment, and sequentially growing an undoped GaN layer, an N-type layer, a multi-quantum well layer and a P-type layer on the Al polar surface of the AlN buffer layer. When the surface of the AlN buffer layer is an Al polar surface, the lattice matching degree between the AlN buffer layer and the undoped GaN layer is higher. Therefore, the manufacturing method can improve the lattice matching degree between the AlN buffer layer and the GaN layer, thereby improving the crystal quality of the grown light-emitting diode epitaxial wafer and further improving the luminous efficiency of the LED.

A method for growing aluminum indium nitride (AlInN) films on silicon substrates comprises several steps: firstly, arranging a silicon substrate in a reaction chamber; secondly, providing multiple reaction gases in the reaction chamber, wherein the reaction gases include aluminum precursors, indium precursors and nitrogen-containing gases; finally, dynamically adjusting flow rates of the reaction gases and directly growing an AlInN layer on the silicon substrate via a crystal growth process. By directly forming an AlInN layer on the silicon substrate, lattice matching is increased, residual thermal stress is reduced and film quality is improved. In addition, fabrication process is simplified and thus cost is reduced.