124 results about "Recombination rate" patented technology

In a photoelectric conversion device, in a contact between a p-type semiconductor 3a and an electrode 2, an n-type semiconductor 6 of a conductivity type opposite to that of the p-type semiconductor is provided between the p-type semiconductor 3a and the electrode 2. The existence of the n-type semiconductor 6 allows a recombination rate of photo-generated carriers excited by incident light to be effectively reduced, and allows a dark current component to be effectively prevented from being produced. Therefore, it is possible to improve photoelectric conversion efficiency as well as to stabilize characteristics. Further, a tunnel junction is realized by increasing the concentration of a doping element in at least one or preferably both of the p-type semiconductor 3a and the n-type semiconductor 6 in a region where they are in contact with each other, thereby keeping ohmic characteristics between the semiconductor and the electrode good.

The invention discloses bismuth ferrite nano fiber and a preparation method thereof. The preparation method of the bismuth ferrite nano fiber comprises the following steps: 1) using bismuth nitrate or a hydrate thereof and iron nitrate or a hydrate thereof as raw materials, dissolving the two raw materials in a solvent, adding a complexing agent, stirring to obtain bismuth ferrite sol, then adding a polymer as a spinning aid in the bismuth ferrite sol, and stirring evenly to obtain a precursor solution; 2) performing electrostatic spinning of the precursor solution to obtain bismuth ferrite precursor fiber; and 3) performing heat treatment of the bismuth ferrite precursor fiber to remove the polymer to obtain the bismuth ferrite nano fiber. In the BiFeO3 (bismuth ferrite) nano fiber prepared by the preparation method, crystal grains of the fiber are arranged along the axial direction to form a bamboo-joint-like structure. The bismuth ferrite nano fiber has a narrow forbidden bandwidth (2.1-2.3 eV), a high utilization rate of visible light, a large specific surface area and few crystal boundaries and crystal faces, can effectively improve the separation of photogenerated carriers and reduce the recombination rate of photogenerated electrons and holes, has a high quantum efficiency, and shows more excellent photocatalytic properties than nanoparticles.

A sensitized photovoltaic device (10) provides for a reduction of the charge recombination rate and charge transport time. The device (10) includes a first electrode (12) comprising a transparent conducting oxide and a plurality of carbon nanostructures (16) formed thereon. A first layer (18) is formed on the carbon nanostructure (16) and comprises a first conduction band level (44). A second layer (20) is formed on the first oxide (18) and comprises a second conduction band level (46) higher than the first conduction band level (44). A sensitizer (22) is formed on the second layer (20) and comprises a lowest unoccupied molecular orbital level (48) higher than the second conduction band level (46). An electrolyte (24) is positioned over the sensitizer (22), and a second electrode (26) comprising a transparent conducting oxide and a layer of catalyst is formed over the electrolyte (24).

An epitaxial structure of a high-brightness light emitting diode and an implementation method thereof belong to the technical field of semiconductor production. At least three pairs of coupled quantum wells grow. When each pair of coupled quantum wells grow, firstly, quantum well layers low in In content grow; and secondly, luminous quantum well layers grow, In content of each quantum well layer low in In content gradually increases along the growth direction, and a thin GaN barrier layer grows between each adjacent quantum well layer low in In content and luminous quantum well layer. A coupled quantum well structure which is low in In content and gradually increases in composition grows before a luminous quantum well by a variable temperature and variable precursor flow method, and accordingly a quantum well low in In content cannot adsorb photons emitted by the quantum well again, built-in electric field can be lowered, localization of carriers is enhanced to increase radiative recombination rate, and internal quantum efficiency of the light emitting diode is improved greatly.

The invention belongs to the field of nano material preparation, and relates to a method for comodifying a titanium dioxide nanotube array with silver and cadmium sulfide nanoparticles, which comprises the following steps: carrying out ultrasonic cleaning on a high-purity titanium sheet to remove oil, removing the natural oxide film, and carrying out secondary anodization to prepare an ordered titanium dioxide nanotube array; and treating the titanium dioxide nanotube array with a coupling agent, depositing Ag nanoparticles by an SILAR (successive ionic layer adsorption and reaction) process, and modifying the Ag-modified titanium dioxide nanotube array with CdS nanoparticles, thereby obtaining the Ag/CdS-nanoparticle-comodified titanium dioxide nanotube array. The invention is simple to operate and has the advantage of low cost; the noble metal and narrow-energy-gap semiconductor nanoparticles are utilized to comodify the titanium dioxide nanotube array, thereby effectively widening the absorption range of TiO2 in the visible light region and lowering the recombination rate of the electron-hole pair; and the invention has wide prospects in the aspects of solar cells, toxic or harmful pollutant degradation and the like.

The invention relates to a genetic map construction and haplotype analytical method based on single-cell whole genome sequencing, and a device used for the method. The genetic map construction method comprises the following steps: comparing a whole genome sequence of a single cell of a species with a reference sequence to obtain a statistic result of a single nucleotide polymorphic site genotype; performing parent type classification of the genotype result to obtain a most appropriate male parent/female parent (a/b) result, so as to obtain a minimum recombination frequency of all the cells in the statistic result; according to the type classification result, dividing a linkage area (bin); calculating a change ratio of a/b to obtain recombination rates between all adjacent bins; and finally obtaining the genetic map according to the recombination rate of each recombinant site. The method of the invention can obtain a genetic map with high resolution by using a single cell, can not only applicable to human, but also applicable to some higher organisms with limited fertility, especially to endangered species.

The invention discloses a processing method of inefficient solar cell sheets. The processing method comprises the steps of screening out inefficient solar cell sheets from solar cell sheet products, and disposing the inefficient solar cell sheets into an annealing furnace for annealing with hydrogen. In the embodiment of the invention, the inefficient cell sheets are annealed with hydrogen. Since hydrogen can reduce oxide on metal electrodes, the contact resistance between the metal electrodes and silicon is thereby reduced, and accordingly the total series resistance of the inefficient cell sheets is reduced. Moreover, since hydrogen possesses a passivation function, the electroactive impurities are passivated, the recombination rate of carriers on cell surfaces and the lifetime of minority carriers are prolonged. Therefore, the shunt resistance of the cell sheets is improved and the reverse leakage current density is reduced, accordingly the filling factors of the cell sheets are increased and the conversion efficiency is improved.

The invention relates to a red organic electroluminescence device and a fabrication method thereof. By using vacuum evaporation technique, a red organic electroluminescence device is fabricated, and the host materials are 4, 4'-N, N'-dicarbazole-diphenyl/ 2, 9-dimethyl-4, 7-diphenyl-1, 10- phenanthroline/ 8-hydroxyl quinoline/ lithium fluoride (LiF)/ aluminum (Al) with a configuration of indium tin oxide (ITO)/ 4, 4'-di[N-(p-methylphenyl)-N-phenyl-amino]dimethyl/ Eu(TTA)3phen, wherein Eu(TTA)3phen is the classical europium complex with trifluoroacetyl thiophene acetone (TTA) and o-phenanthroline (phen) as the first and the second ligands. The low-pressure oxygen plasma treatment on ITO anode is used to enhance hole injection, and the thickness of LiF and Al is precisely adjusted to suitably limit electron injection. The maximum electroluminescence current efficiency of the device is 9.53cd/A, the maximum power efficiency is 5.35lm/W, the maximum external quantum efficiency is 5.15 percent, and the corresponding maximum recombination rate of the device is 85.8 percent.

The invention relates to an epitaxial growth method for improving the inner quantum efficiency of a GaN-based LED, belonging to the technical field of semiconductors. The method comprises the following steps of: alternately inputting ammonia gas as well as Group III metal organic source materials of gallium and indium in a growth reaction chamber in a pulsing way during the growth of an In-Ga-N quantum well layer of a GaN-based blue/green light LED active area; and forming a In-Ga-N quantum well luminous layer with high luminous efficiency in a modulation growth process under a set duration, a set interval and a set pulse period. The method can weaken an internally-built electric field of the In-Ga-N/GaN quantum well, improve the quantum localization effect, enhance the radiative recombination rate and increase the inner quantum efficiency of luminescence so as to improve the luminous efficiency and the brightness of the LED. The method is suitable for the MOCVD (Metallo Organic Chemical Vapor Deposition) epitaxial growth of a nitride-based blue/green light LED epitaxial material with high brightness and high luminous efficiency.

The invention provides a method of preparing a quantum dot light-emitting diode. The method comprises steps of forming a cathode, forming an electron transport layer, forming a light emitting layer, forming a hole transport layer, and forming an anode. The step of forming a light emitting layer is implemented as follows: forming a coating including an electron barrier compound next to the electrontransport layer; forming a coating containing a quantum dot material on the surface of the coating containing the electron barrier compound; and/or forming a coating containing a hole transport compound on the surface of the coating containing the quantum dot material. The electron barrier compound and the hole transport compound make ligand exchange with the surface ligand of the quantum dot material. In addition, the invention also provides a quantum dot light-emitting diode. According to the quantum dot light-emitting diode provided by the invention, the electron transport rate is reducedand/or the hole transport rate is increased to regulate the injection balance of electrons and holes and improve the carrier recombination rate of the QLED device; and thus the luminous efficiency ofthe QLED device is improved.

The invention discloses a p-i-n-type antimony selenide thin-film solar cell which comprises, from top to bottom, a top electrode layer, a p-type antimony selenide semiconductor layer, an intrinsic semiconductor i-type layer, an n-type antimony selenide semiconductor layer, and a bottom electrode layer. The structure of the solar cell can reduce the lattice mismatch of a pn-junction interface and reduce the high recombination rate due to the high interfacial defect density. Further, the intrinsic semiconductor i-type layer is inserted into the homogeneous antimony selenide pn junction so that a built-in field can be expanded in the intrinsic semiconductor i-type layer, thereby being beneficial to the separation of photon-generated carrier charges, increasing the collection efficiency of the photon-generated carriers, and further improving the performance of the solar cell. The solar cell is simple in preparation process and suitable for industrial production and application.

The invention discloses an LED epitaxial wafer and a manufacturing method thereof, and belongs to the technical field of semiconductors. The multi-quantum well layer of the LED epitaxial wafer includes alternately grown multiple quantum well layers and multiple quantum barrier layers. Each quantum well layer includes a first sub-layer, a second sub-layer and a third sub-layer which are successively stacked. The first sub-layer, the second sub-layer, and the third sub-layer are all InxGa1-xN layers, 0<x<1. The In components in the first sub-layer and the third sub-layer accounts for 25% to 35%of the In component in the second sub-layer. The part of each quantum well layer in contact with the quantum barrier layer is low in In component content, which can weaken a polarization effect due tolattice mismatch at an interface between the quantum well layer and the quantum barrier layer and improve the radiation recombination rate of electrons and holes, thereby improving the luminous efficiency of the LED. The middle part of each quantum well layer has higher In component content, which can further improve the luminous concentration of the LED.

The invention discloses a preparation method of a nanometer titania photocatalyst for degrading VOC. The method comprises the following steps: S1, putting nanometer titania powder into a tube furnace, and then introducing ammonia gas of which the purity is not lower than 99.9%; S2, heating up the furnace body to 550-750 DEG C at the heating rate of 4 DEG C/min to 10 DEG C/min, and carrying out heat preservation, wherein the ammonia gas is lastingly introduced in the process S2; S3, carrying out vacuum calcination under the condition that the air pressure is lower than the barometric pressure in the tube furnace, wherein the heat preservation temperature in the S3 is the same as that in the S2; and S4, cooling and taking out a sample. The nanometer titania photocatalyst prepared by adopting the method disclosed by the invention has the relatively strong visible light absorption ability and relatively low electron-cavity recombination rate, high-concentration benzene pollutants can be quickly and completely degraded, and 5.256*10<-3>mg of benzene contained in a space of 0.002m<3> can be completely degraded only by consuming 0.1g of mass energy within four hours under visible light irradiation.

The invention discloses a method for preparing a CdS quantum dot/Bi2MoO6/graphene composite photocatalyst and belongs to the technical field of synthesis of inorganic environmental-friendly photocatalytic materials. According to key points of the technical scheme of the present invention, the method for preparing the CdS quantum dot/Bi2MoO6/graphene composite photocatalyst disclosed by the invention comprises the following step: compounding CdS quantum dots, Bi2MoO6 and graphene, to obtain the CdS quantum dot/Bi2MoO6/graphene composite photocatalyst, wherein a molar ratio of the CdS quantum dot to Bi2MoO6 is 1:(0.1-0.5); and the mass ratio of the graphene to Bi2MoO6 is (0.03-0.15):1. According to the CdS quantum dot/Bi2MoO6/graphene composite photocatalyst prepared by the method disclosed by the invention, the recombination rate of photo-induced electrons and holes is effectively reduced, photocatalytic water splitting hydrogen production catalytic activity of the CdS quantum dots is improved, and a light etching phenomenon of the CdS quantum dots in the photocatalytic water splitting process is retarded. Moreover, the method has the advantages of mild operating conditions, low agglomeration degree of the prepared product and high photocatalytic activity.

The invention discloses a boron diffusion method of an N type silicon chip, a crystalline silicon solar cell and a manufacturing method of the crystalline silicon solar cell. The boron diffusion method comprises the following steps of a deposition stage: placing the silicon chip subjected to wet etching into a diffusion furnace, and then introducing nitrogen, oxygen and a boron source for depositing the surface of the silicon chip; a diffusion stage: raising the temperature of the silicon chip with the surface being deposited to a preset temperature for promoting the diffusion of boron; a temperature dropping stage: dropping the temperature of the silicon chip with the boron being diffused, and introducing nitrogen in the temperature dropping process to obtain the silicon chip with the boron being diffused. After the deposition diffusion process disclosed by the invention is adopted, the concentration of boron atoms on the surface of the silicon chip is reduced, the recombination rate and the lattice damage of the surface are reduced, the STDEV (standard deviation) is controlled to be about 2.0, the sheet resistance uniformity of boron diffusion is improved, the battery conversion efficiency is improved, the consumption of boron sources is also reduced, BGS (borosilicate glass) is prevented from being excessively generated, and the cost is reduced.

The invention discloses a high performance X-ray sensor based on CH3NH2PbBr3 perovskite single crystals and a preparation method thereof. The high performance X-ray sensor is low in cost and high in performance and can be used for digital X-ray detection. The sensor comprises 1. a CH3NH2PbBr3 perovskite single crystal substrate which is prepared by using a temperature changing crystallization method, wherein the single crystals have high crystallization quality and the preparation method is suitable for preparation of the large area substrate; 2. row electrodes which are arranged on the perovskite crystals and formed by conductive material of less X-ray absorption; and 3. column electrodes which are arranged below the perovskite crystals and mutually perpendicular to the row electrodes and formed by metal material of great conductive performance. The CH3NH2PbBr3 perovskite single crystal substrate has high thickness and high atomic number metal and has high photoelectric conversion efficiency for X-rays; besides, the recombination rate of the photo-generated carries in the CH3NH2PbBr3 perovskite single crystal substrate is low so that the X-ray sensor has high sensitivity.

The invention provides a heavy section BFe30-1-1/35CrMo explosion welding high-strength high-anticorrosion composite plate. Firstly, the explosion speed of dynamite is controlled within about 800-1000m/s by the optimal design of dynamite formula. Secondly, by a principle of selecting the lower limit of the charging main parameter, the charging auxiliary parameters such as clearance and charging size of basic composite plate are reasonably designed, sand soil foundation added by water is selected and configured and the water content and density thereof are controlled, thus ensuring the once recombination rate of the heavy section BFe30-1-1/35CrMo explosion welding high-strength high-anticorrosion composite plate to achieve 100 percent and the adhesion strength thereof to achieve or even exceed the national standard, and avoiding the crack generation of the heavy section composite plate and high-strength basic plate during the explosion welding process. Finally, the subsequent crack of the composite pate is ensured not to be generated in the subsequent processing by the formulation of heat disposal parameters. The composite plate has ultra-high anticorrosion performance and extremely high high-temperature strength and anti-impact toughness.

The invention relates to controlling the recombination rate in a bipolar semiconductor component. Disclosed is a method for controlling the recombination rate in the base region of a bipolar semiconductor component, and a bipolar semiconductor component.

The invention provides a GeSn quantum well infrared illuminator with a strain source. The structure is characterized in that a relaxation layer GeSn is arranged on a silicon substrate; strain source potential barriers n+ SiGe and p+ SiGe are arranged on the relaxation layer and grows at the peripheral region of an active region GeSn in pairs; and one end of the strain source potential barrier SiGe is a metal contact electrode. The lattice constant of the material of the strain source SiGe is smaller than that of the material of the active region GeSn, thereby forming single-axis compression strain along the z axis direction on the active region GeSn material, and forming a double-axis tensile strain along the xy plane; the strain state facilitates the GeSn material to change from an indirect band gap to a direct band gap; and through forming a heterojunction quantum well structure through the GeSn and the SiGe, fast and efficient radiative recombination of electron-hole is realized. The structure can limit electrons and holes in the well efficiently, thereby enlarging recombination rate of the electron and hole pairs, and improving luminous efficiency of an illuminator.

The invention discloses a hot-rolled stainless-steel-aluminium-stainless-steel composite board production method and application. The composite board consists of three parts A, B and C, the A and the C are stainless steel plates and the B is a pure aluminium plate, wherein the stainless steel plates A and C are 201, 202, 303, 304 and 316L stainless steel plates and have the specifications of length*width*thickness of 2,440mm*1,220mm*(0.3 to 2.5mm); and the pure aluminium plate B is a civil 1050-series pure aluminium plate and has the specification of length*width*thickness of 2,440mm*1,220mm*(1.0 to 50mm). Compared with the prior art, the hot-rolled stainless-steel-aluminium-stainless-steel composite board production method has the advantages that the composite board with the thickness of 1.5mm to 50mm can be produced; the interface recombination rate reaches 100 percent; the working intensity is low; the yield is high; energy is saved; and no pollution or noise is generated.

The invention relates to the preparation field of a photoelectric material, particularly to an LED epitaxial wafer. The LED epitaxial wafer comprises a substrate, a gallium nitride layer, an N type gallium nitride layer, an aluminum gallium nitride/gallium nitride multi-quantum-well layer, an electron barrier layer, a P type aluminum gallium nitride layer, a P type contact layer and a P type electrode which are arranged in an overlaying manner in sequence; and the P type aluminum gallium nitride layer is a Mg-doped multilayered polarization-induced Al<x>Ga<1-x>N layer, wherein x is 0.3 to 0.05. The invention aims to solve the technical problems of low luminous efficiency, low internal quantum efficiency and the like caused by electronic leakage and relatively low radiative recombination rate due to spontaneous and piezoelectric polarization in the LED; and the LED epitaxial wafer has the advantages of simple structure, simple and convenient process, convenience in production and suitability for industrial production.

The invention discloses a preparation method for a stannous methyl amino iodide-titanium dioxide visible light catalytic material. The preparation method comprises the following steps: 1) preparing ammonium methyl iodide; 2) preparing stannous iodide; 3) preparing stannous methyl amino iodide; 4) preparing the stannous methyl amino iodide-titanium dioxide visible light catalytic material: adding stannous methyl amino iodide and tetrabutyl titanate into normal hexane, mixing, heating and stirring at 70 DEG C for reaction under reflux, centrifugally separating turbid liquid by using a high speed centrifuge, adding into deionized water after centrifugal separation, magnetically stirring, filtering, washing and drying to obtain dry solid powder, and putting into a muffle furnace for roasting, thereby acquiring the methyl amino stannous iodide-titanium dioxide visible light catalytic material. The preparation method is simple and convenient in operation and low in cost; the photoproduction electron generated by the visible light catalytic material can quickly transfer to a TiO2 guide tape; the recombination rate of photoproduction electron and hole can be reduced; the separation of the photoproduction electron-hole on the material interface can be promoted; the visible light catalytic activity of the material is promoted.