1593results about How to "Improve injection efficiency" patented technology

A method of growing an AlGaN semiconductor material utilizes an excess of Ga above the stoichiometric amount typically used. The excess Ga results in the formation of band structure potential fluctuations that improve the efficiency of radiative recombination and increase light generation of optoelectronic devices, in particular ultraviolet light emitting diodes, made using the method. Several improvements in UV LED design and performance are also provided for use together with the excess Ga growth method. Devices made with the method can be used for water purification, surface sterilization, communications, and data storage and retrieval.

A light emitting device having superior responsibility is provided. A pixel electrode (anode) connected to a drain wiring of an current control TFT has a slit. The slit becomes a path for light emitted from an EL layer, and emitted light can be extracted using a light shielding metallic film as the pixel electrode. A material having a low resistance can thus be used as the pixel electrode, and therefore a light emitting device having superior responsibility can be obtained.

A tandem organic light emitting diode (OLED) device comprised of multiple stacked single OLEDs electrically connected in parallel via transparent interlayer is recited herein. Transparent interlayers are coated by charge injection layers in order to enhance the charge injection efficiency and decrease the operation voltage. Transparent nanomaterials, such as carbon nanotube sheets (or graphene, graphene ribbons and similar conductive transparent nano-carbon forms) are used as Interlayers or outer electrodes. Furthermore, functionalization of carbon nanotubes inter layers by n-doping (or p-doping) converts them into common cathode (or common anode), further decreasing operation voltage of tandem. The development of these alternative interconnecting layers comprised of nanomaterials simplifies the process and may be combined with traditional OLED devices. In addition, novel architectures are enabled that allow the parallel connection of the stacked OLEDs into monolithic multi-junction OLED tandems.

A storage element 3 has an arrangement in which magnetization fixed layers 31 and 32 are provided above and below a storage layer 17 for storing information based on the magnetization state of a magnetic material through intermediate layers 16 and 18, directions of magnetizations M15 and M19 of ferromagnetic layers 15 and 19 closest to the storage layer 17 of the magnetization fixed layers 31 and 32 above and below the storage layer 17 are opposite to each other, the two intermediate layers 16 and 18 above and below the storage layer 17 have a significant difference between sheet resistivity values thereof and in which the direction of a magnetization M1 of the storage layer 17 is changed with application of an electric current to the lamination layer direction to record information on the storage layer 17.

The present invention provides a battery positive electrode and a preparation method thereof, and a lithium ion secondary battery. The positive electrode comprises a conductive substrate and a material layer coated on the conductive substrate surface, wherein the material layer comprises a first conductive material layer attached on the conductive substrate, a first active material layer attached on the first conductive material layer, a second conductive material layer attached on the first active material layer, and a second active material layer attached on the second conductive material layer, and the compact density of the second active material layer is lower than the compact density of the first active material layer. According to the present invention, characteristics of excellent pore size distribution, good electrolyte infiltration and material shedding resistance are provided, and the prepared battery has characteristics of good cycle performance, low internal resistance, excellent rate capability, excellent high temperature storage performance and high energy density.

The invention discloses an LED (Light Emitting Diode) epitaxial structure with a P (Positive) type superlattice and a preparation method thereof. The epitaxial structure comprises a substrate, wherein a GaN (Gallium Nitride) buffer layer, an undoped GaN layer, an n (negative) type GaN layer, a multi-quantum well luminous layer, a first P type GaN layer, a P type AlGaN (Aluminium Gallium Nitride) electronic blocking layer and a second P type GaN layer are sequentially arranged on the substrate from bottom to top, and the P type superlattice formed by a PInGaN (P type Indium Gallium Nitride) potential well layer and a PAlGaN potential barrier layer in a periodic interactive overlapping way is arranged between the P type AlGaN electronic blocking layer and the second P type GaN layer. The PInGaN potential well layer in the P type superlattice generates and constrains a great number of holes for the formation of a two-dimensional hole high-density state; the PAlGaN potential barrier layer hinders the escape of the holes; in such a way, the transverse spreading of the holes is improved, the electron overflow can be prevented, the hole injection efficiency is increased and the electron and hole recombination probability is improved; and therefore, the brightness of a chip can be improved by 5-10%.

The invention discloses a gallium-nitride-based light emitting diode capable of improving electron injection efficiency. The gallium-nitride-based light emitting diode comprises a substrate, a gallium nitride nucleation layer, a buffer layer, an n-type contact layer, a lower multicycle n-type electron coupling layer, a lower tunneling potential barrier layer, an upper multicycle n-type electron coupling layer, an upper tunneling potential barrier layer, a multicycle active luminous layer, a negative electrode, a p-type electron blocking layer, a p-type contact layer and a positive electrode, wherein the gallium nitride nucleation layer is manufactured on the substrate; the buffer layer is manufactured on the gallium nitride nucleation layer; the n-type contact layer is manufactured on the buffer layer; a table top is formed on one side of the upper surface of the n-type contact layer; the lower multicycle n-type electron coupling layer is manufactured on the other side of the table top on the n-type contact layer; the lower tunneling potential barrier layer is manufactured on the lower multicycle n-type electron coupling layer; the upper multicycle n-type electron coupling layer is manufactured on the lower tunneling potential barrier layer; the upper tunneling potential barrier layer is manufactured on the upper multicycle n-type electron coupling layer; the multicycle active luminous layer is manufactured on the upper tunneling potential barrier layer; the negative electrode is manufactured on the table top of the n-type contact layer; the p-type electron blocking layer is manufactured on the multicycle active luminous layer; the p-type contact layer is manufactured on the p-type electron blocking layer; and the positive electrode is manufactured on the p-type contact layer to form the structure of the gallium-nitride-based light emitting diode.

An in-situ injection of soil and groundwater—high pressure rotary jet grouting in-situ remediation system and method. The system has an agent dispensing station, high pressure grouting pump, air compressor, rotary jet grouting drilling machine, second double-pipe water flow joint, automatic lifting mechanism for grouting drill pipe of rotary jet grouting drilling machine, high pressure jet drill pipe, inner tube for high pressure jet triple drill pipe, outer tube for high pressure jet triple drill pipe, agent jet nozzle, an air jet nozzle, cemented carbide block and a drill bit. Parameters are arranged according to the triangle method to ensure that the remediation area is covered within the diffusion radius of the agent. After positioning the GPS measuring point, a guided-boring rig is positioned at the center of the injection point. The high pressure injection remediation uses a double-pipe: using gas and liquid fluids to spread the soil while cutting the soil from bottom to top to achieve thorough mixing of the remediation agent with soil and groundwater; quickly combining laboratory testing to obtain parameters for remediation agent residues, pH values, and contaminant concentrations to verify the in-situ remediation effect and monitor the residual agent.

Disclosed are an optical transceiver and an passive optical network using the same. The optical transceiver includes a polarization splitter for splitting injected light input from an outside of the optical transceiver into a first polarization component and a second polarization component, a light injected transmitter for receiving the first polarization component and outputting an optical signal generated based on the first polarization component, and an optical receiver for detecting an electrical signal based on the second polarization component.

The invention discloses a nitride light-emitting device for improving the light-emitting efficiency by an electron barrier layer. The light-emitting device disclosed by the invention is provided with the electron barrier layer which is doped with aluminum in a non-uniform and non-periodic manner, and has changed Al components. According to the invention, two key problems of improving the light-emitting efficiency are effectively and simultaneously solved, namely a potential barrier of hole tunneling is reduced and the injection efficiency of a hole is improved; and furthermore, parasitic electron inversion layers are prevented from being formed on interfaces of a quantum barrier and the electron barrier layer by a traditional structure. However, the effect on stopping electrons by a multilayer structure is more obvious and two current carriers of the electrons and the hole are distributed in each quantum well of an active layer in a more balanced and uniform way, so as to obtain the more uniform light gain. Therefore, the light-emitting device provided by the invention can effectively overcome a parasitic quantum well phenomenon and has a smaller threshold current. Furthermore, a waveguide structure is provided with a higher optical limiting factor so that a stronger light-emitting strength is obtained; and therefore, the electric performance and the optical performance of a laser device can be simultaneously improved.

The invention provides a near-ultraviolet LED lamp with a novel electron blocking layer, and a preparation method thereof. A near-ultraviolet LED epitaxial wafer structure comprises a graphical sapphire substrate, a low-temperature GaN nucleating layer, a high-temperature non-doped GaN buffer layer, an n-type GaN layer, an InGaN/AlGaN multiple-quantum well active layer, a p-type AlGaN/InGaN superlattice electron blocking layer, a low-temperature lightly-doped p-type AlInGaN hole expansion layer, a high-temperature p-type GaN layer and a p-type InGaN contact layer. The electron blocking layer adopts a p-type Al<y1>Ga<1 y1>N/In<x1>Ga<1 x1>N superlattice structure. Along with the increase of the number of superlattice periods, the InGaN thickness is reduced step by step, the Mg doping concentration is increased step by step and the hole concentration is increased. By the invention, the hole injection efficiency is effectively improved and the electron hole recombination luminous efficiency is enhanced, so the near-ultraviolet LED luminous efficiency is increased.

The invention provides a blue LED epitaxial structure with a suppression polarization effect barrier layer, and relates to the technical field of light emitting diodes. The blue LED epitaxial structure comprises a substrate, an AlN buffer layer, a U-type GaN layer, an N-type GaN layer, a shallow quantum well layer, an active region, an electron blocking layer, and a P-type GaN layer in sequence from bottom to top, the suppression polarization effect barrier layer is inserted between the shallow quantum well layer and the active region, and the suppression polarization effect barrier layer comprises an AlxGal-xN layer and a SiN layer from bottom to top. According to the blue LED epitaxial structure, a novel barrier layer is inserted into the conventional epitaxial structure, the stress is released, polarization is suppressed, the defect density is reduced, the radiative recombination probability is improved, the polarization effect is reduced, and the quantum efficiency in the LED is improved.

The invention discloses a light-emitting diode epitaxial wafer and a manufacture method thereof and belongs to the field of semiconductor technology. The epitaxial wafer comprises a substrate, a low-temperature buffer layer grown on the substrate, a non-doped gallium nitride layer, a type-N gallium nitride layer, a multiple-quantum well layer and a type-P gallium nitride layer. At least one quantum barrier from one side of the type-N gallium nitride layer is grown by AlxGa1-xN; 0<x<0.3. At least one quantum barrier layer from one side of the type-P gallium nitride layer is grown by InzGa1-zN; 0<z<0.15. The type-P gallium nitride layer is directly grown on the multiple-quantum well layer. The quantum barrier layers close to the type-N gallium nitride layer are provided with high potential barrier, the quantum barrier layers close to the type-P gallium nitride layer are provided with low potential barrier, electron overflow is reduced, hole injection efficiency is improved, more electrons and holes are composited in the quantum well layer, and internal quantum efficiency of the light-emitting diode is improved accordingly.

The invention provides a light-emitting diode with a novel P-type electron barrier layer structure and a growth method. The LED epitaxy structure of the light-emitting diode comprises a substrate, a low-temperature GaN buffer layer, a GaN non doping layer, an N-type GaN layer, a multiple quantum well layer, a low-temperature GaN layer, a P-type InAlGaN electron barrier layer, a high-temperature P-type GaN layer and a P-type contact layer which are sequentially arranged from bottom to top. According to a P-type InyAlxGal-x-yN electron barrier layer of the composite structure, In components are added, and the InyAlxGal-x-yN lattice constant is adjusted, so that lattice matching between the P-type GaN layer and the multiple quantum well layer can be achieved, dislocation density is reduced, lattice quality is improved, and expected energy band gap value and energy band drift rate are obtained. Consequently, electron leakage is effectively reduced, and the injection rate of holes is improved. Moreover, a gradually-changing structure of the P-type InAlGaN drift rate is designed, and the restriction to hole vertical migration is avoided, so that the injection efficiency of holes is improved, and the light-emitting efficiency of a GaN-based light-emitting diode is further improved.

A solid state light-emitting device comprising: a first electrode coupled to a first charge injecting layer; a second electrode coupled to a second charge injecting layer; an emissive layer comprising a perovskite material, wherein the emissive layer is provided between the first and second charge injecting layers; and wherein the bandgaps of the first and second charge injecting layers are larger than the bandgap of the emissive perovskite layer.

The invention relates to a top emission organic light-emitting device. The top emission organic light-emitting device comprises a substrate, a cathode electrode layer, an electronic transmission layer, an electron hole barrier layer, a luminous layer, an electronic barrier layer, an electron hole transmission layer and an anode electrode all of which are arranged in a stack-up mode. The electronic transmission layer comprises a plurality of sub-transmission layers which are arranged in a stack-up mode. Each sub-transmission layer is mainly made of main materials and doping materials mingled with the main materials. The light of the top emission organic light-emitting device is emitted from the anode electrode on the top, and therefore the problem that the luminous efficiency of a traditional top emission electrode is low is solved. The gradient doping method is adopted in the electronic transmission layer of the top emission organic light-emitting device, ohm contact is formed between the electronic transmission layer and the cathode electrode layer, and therefore the carrier injection efficiency is improved, the doping concentration is reduced gradually along with the increasing of the thickness of the electronic transmission layer, electrons are injected and transmitted in a gradient mode, carrier injection is controlled, excition recombination can be controlled, and the high light-effect is achieved. The invention further relates to a manufacturing method for the top emission organic light-emitting device.

The invention provides an LED epitaxial layer growth method for improving luminous efficiency and an LED epitaxial layer. A P type hole injection layer comprises a first double-layer unit and a second double-layer unit. The first double-layer unit comprises a first AlGaN layer and a first GaN layer, the thickness of the first AlGaN layer and the first GaN layer ranges from 2 nm to 5 nm, the ratio of the first AlGaN layer to the first GaN layer in one period ranges from 1:1 to 3:1, and the period ranges from 5 to 10. The second double-layer unit comprises a second AlGaN layer and a second GaN layer, the thickness of the second AlGaN layer and the second GaN layer ranges from 2 nm to 5 nm, the ratio of the second AlGaN layer to the second GaN layer in one period ranges from 1:1 to 3:1, and the period ranges from 5 to 10. The P type hole injection layer is formed by a P type AlGaN/GaN superlattice layer which grows at a low temperature and a P type AlGaN/GaN superlattice layer which grows at a high temperature, the Droop effect of an LED chip under the high current density condition is effectively reduced, injection efficiency of charge curriers is improved, and luminous efficiency of devices is improved.

The invention relates to a device and method for cleaning, activating or pre-treating workpieces by blasting a carbon dioxide snow which is produced from pressurised CO2-containing fluids and at least one type of carrying compressed gas and is accelerated by means of a discharge nozzle (14), wherein a two-phase carbon dioxide mixture of a carbon dioxide gas and carbon dioxide particles is produced in an agglomeration chamber (8) by agglomerating and compressing carbon dioxide snow crystals which are radially added to the carrying gas in a multistage mixing chamber (10, 11, 12) comprising a central jet pipe (4), around which the carbon dioxide mixture circulates and which is used for supplying said carrying gas in such a manner that a high-energy turbulent gas flow for processing a workpiece is obtainable.