134results about How to "Narrow bandgap" patented technology

Disclosed is a semiconductor light-emitting element, comprising an n-type-cladding layer; a light guide layer positioned on the n-type cladding layer; a multiple quantum well structure active layer positioned on the light guide layer; a p-type carrier overflow prevention layer positioned on the active layer and having an impurity concentration of 5×10¹⁸ cm⁻³ to not more than 3×10¹⁹ cm⁻³; a p-type light guide layer positioned on the p-type carrier overflow prevention layer and-having an impurity concentration of 1×10¹⁸ cm⁻³ or more and less-than that of the p-type carrier overflow prevention layer; and a p-type cladding layer positioned on the p-type light guide layer and having a band gap narrower than the p-type carrier overflow prevention layer, and a method of manufacturing the same.

The invention relates to a conjugated polymer based on condensed ring thiophene and diazosulfide, a preparation method and an application of the conjugated polymer as an active layer material in organic optoelectronic devices, such as polymer solar energy cells, organic field effect transistors and organic light emitting diodes. The conjugated polymer based on condensed ring thiophene and diazosulfide has an excellent sunlight capture ability and a hole transmission ability, and the conjugated polymer solution has good processability, thermostability, charge transmission performance and lightadsorption and is an ideal organic semiconducting material in the organic electronic devices, such as solar energy cells, field effect transistors and light emitting diodes. A general formula of the conjugated polymer is shown as above.

A multi-chip light emitting device (LED) lamp for providing white light includes first and second broadband LED chips. The first LED chip includes a multi-quantum well active region having a first plurality of alternating active and barrier layers. The first plurality of active layers respectively include different relative concentrations of at least two elements of a first semiconductor compound, and are respectively configured to emit light of a plurality of different emission wavelengths over a first wavelength range. The second LED chip includes a multi-quantum well active region having a second plurality of alternating active and barrier layers. The second plurality of active layers respectively include different relative concentrations of at least two elements of a second semiconductor compound, and are respectively configured to emit light of a plurality of different emission wavelengths over a second wavelength range including wavelengths greater than those of the first wavelength range. The light emitted by the first and second LED chips combines to provide white light. Related devices are also discussed.

The present invention provides a one-step and room-temperature process for depositing nanoparticles or nanocomposite (nanoparticle-assembled) films of crystalline titanium dioxide (TiO₂) onto a substrate surface using ultrafast pulsed laser ablation of Titania or metal titanium target. The system includes a pulsed laser with a pulse duration ranging from a few femtoseconds to a few tens of picoseconds, an optical setup for processing the laser beam such that the beam is focused onto the target surface with an appropriate average energy density and an appropriate energy density distribution, and a vacuum chamber in which the target and the substrate are installed and background gases and their pressures are appropriately adjusted.

The invention relates to a preparation method of core-shell TiO2/ZnO photocatalyst and the application thereof, which relates to the preparation method of a photocatalyst and the application thereof. The invention solves the problem that the valence band electron of the existing photocatalyst can transit onto a conduction band only under the excitation of ultraviolet radiation. The preparation method of the invention is that: 1. Zn(CH3/COO)2/2H2/O is mixed into a Polyvinyl alcohol solution and heated in step after being dried and then cooled down to room temperature; 2. tetrabutyl titanate, absolute ethyl alcohol and triethanolamine are mixed together and aged, then the product of the step 1 is added into the solution for dissolving following by drying and heat treatment. The core-shell TiO2/ZnO photocatalyst prepared by the invention is painted on cross linked ethylene, layered perovskite, molten salt crystal water and salt or Al-Si material as thermal energy storage material. The electron of the TiO2 in the invention can transit onto the conduction band under common lighting condition, which leads photo electron to be effectively separated.

A nitride semiconductor device includes: a first semiconductor layer made of first nitride semiconductor; a second semiconductor layer formed on a principal surface of the first semiconductor layer and made of second nitride semiconductor having a bandgap wider than that of the first nitride semiconductor; a control layer selectively formed on, or above, an upper portion of the second semiconductor layer and made of third nitride semiconductor having a p-type conductivity; source and drain electrodes formed on the second semiconductor layer at respective sides of the control layer; a gate electrode formed on the control layer; and a fourth semiconductor layer formed on a surface of the first semiconductor layer opposite to the principal surface, having a potential barrier in a valence band with respect to the first nitride semiconductor and made of fourth nitride semiconductor containing aluminum.

The invention discloses a preparation method of metastable phase bismuth oxide and application thereof in photocatalytic degradation of organic pollutants. The preparation method comprises the following steps: carrying out hydrothermal reaction on an aqueous solution which contains ammonium bismuth citrate, urea and hexadecyl trimethyl ammonium bromide to obtain bismuthyl carbonate microflowers; and calcining the bismuthyl carbonate microflowers in an air environment to obtain the metastable phase bismuth oxide beta-Bi2O3/Bi2O2.33@Bi2O2CO3. The preparation method is simple and controllable to operate, and is environmentally friendly. The synthesized metastable phase bismuth oxide has the advantages of visible-light response, large specific surface area, high catalytic activity and the like, has the characteristics of rapidness and high efficiency in a process of visible-light catalytic degradation of the organic pollutants, and can be widely applied to the technical field of treatment of the organic pollutants.

The present invention provides a complementary metal-oxide-semiconductor (CMOS) device and a fabrication method thereof. The CMOSFET device includes a compressively strained SiGe channel for a PMOSFET, as well as a tensile strained Si channel for an NMOSFET, thereby enhancing hole and electron mobility for the PMOSFET and the NMOSFET, respectively. As such, the threshold voltages of the two types of transistors can be obtained in oppositely symmetric by single metal gate.

There is provided a method for producing a multijunction solar cell having four-junctions, the method allowing the area of a device to be increased. On a nucleation site formed on a substrate 2, is grown a semiconductor 2a comprising the same material as the substrate 2 in the shape of a wire. On the semiconductor 2a, are successively grown semiconductors 3, 4, 5, and 6 with a narrower band gap in the shape of a wire. The semiconductor 3 may be directly grown in the shape of a wire on the nucleation site formed on the substrate 2. It is preferred to form the nucleation site by forming an amorphous SiO₂ coating 8a on the substrate 2 and etching a part of the amorphous SiO₂ coating 8a. Further, it is preferred to form an insulating film 8 in the region except the nucleation sites on the substrate 2 by allowing the amorphous SiO₂ coating 8a to remain therein. The semiconductor 2a is GaP; the semiconductor 3 is Al_0.3Ga_0.7As; the semiconductor 4 is GaAs; the semiconductor 5 is In_0.3Ga_0.7As; and the semiconductor 6 is In_0.6Ga_0.4As.

The invention relates to nano-crystal fluorescent powder and a preparation method thereof. The invention belongs to the technical field of luminescent materials. The nano-crystal fluorescent powder is Cu-In-Znx-E/ZnS, wherein E=S or Se, and x is no smaller than 0. The preparation method comprises steps that: copper salt, indium salt, alkanethiol and octadecene are isolated from oxygen, mixed, andheated; long-chain alkyl organic acid is added to the product, the mixture is isolated from oxygen and is heated, such that a reaction source is obtained; zinc salt, long-chain alkyl organic amine and octadecene are isolated from oxygen, mixed, and heated, such that a zinc source is obtained; when E=S, the zinc source is added to the reaction source, and the mixture is heated, such that a colloidal solution 1 is obtained; when E=Se, selenium powder is dissolved, and an obtained selenium source is added to the reaction source; the mixture is heated, such that a colloidal solution 2 is obtained; the zinc source is added to the colloidal solution 2, and the mixture is heated, such that a colloidal solution 3 is obtained; the colloidal solution 1 or 3 is washed, and is subject to vacuum drying, such that the nano-crystal fluorescent powder is obtained. According to the invention, the nano-crystal fluorescent powder contains no rare earth element; the luminescence wavelength is adjustable;the nano-crystal fluorescent powder can be uniformly dispersed in an organic solvent; and the application range of the nano-crystal fluorescent powder is wide. The preparation method is advantaged inhigh yield, low cost, environment-friendliness, easy operation, and suitability for large-scaled productions.

The invention provides a method for preparing an antibacterial and wear-resistant stainless steel permeation layer, belongs to the technical field of stainless steel surface protective coatings, and provides a method for diffusion coating of a uniformly distributed antibacterial and wear-resistant stainless steel permeation layer on a stainless steel matrix workpiece. The reaction process is controllable. The technical scheme comprises the following steps of: 1, putting the stainless steel matrix workpiece into a double-layer metallic glow ion cementation furnace, taking a pure titanium plate as a sputtering target, argon as working gas, and nitrogen or mixed gas of nitrogen and methane as reaction gas for diffusion coating; and 2, putting the stainless steel matrix workpiece subjected to diffusion coating into a vacuumized muffle furnace, introducing oxygen to react with the permeation layer of the stainless steel matrix workpiece, controlling the heating temperature range to be between 400 and 600 DEG C, keeping the temperature for 1.5 to 2 hours, and cooling to room temperature. The method is applied to the technical field of stainless steel surface diffusion coating.

The invention discloses a flexible molybdenum disulfide phototransistor and a preparation method thereof, and mainly solves the problem that an existing flexible transistor is high in fabrication technique difficulty and poor in performance. The phototransistor structurally comprises a grid electrode (1), a dielectric layer (2) and a semiconductor layer (3) from bottom to top, a source electrode (4) and a drain electrode (5) are arranged at two ends of the semiconductor layer (3) and connected with the dielectric layer (2), flexible transparent materials such as PEN (polyethylene naphthalate)of an ITO (indium tin oxide) transparent electrode layer are evaporated on the surface of the grid electrode (1), and 5%-15% potassium hydroxide water solution is doped in the semiconductor layer (3).A device is transferred to a PEN substrate from a silicon substrate by the aid of a substrate transfer technology, molybdenum disulfide materials are doped in the substrate transfer process to reducethe contact resistance of the materials, fabrication technique is simplified, cost is reduced, the performance and the flexibility of the device are improved, and the phototransistor can be used forelectronic, communication and medical equipment.

The invention discloses a preparation method of a bi-color artificial quartz stone slate. The method comprises steps as follows: (1) raw materials are weighed in proportion and stored separately; (2)an antibacterial agent is added to resin and stirred and mixed in vacuum; pigments, a coupling agent, glass particles, artificial quartz particles, natural quartz sand and quartz powder are stirred and mixed in vacuum; finally, a curing agent is added and stirred and mixed in vacuum, and a mixture is obtained; (3) the mixture is uniformly spread on a template; (4) the template is sent into a vacuum vibration forming press for vibratory pressing forming; (5) primary curing and secondary curing are performed sequentially after vibratory pressing forming. The mechanical properties such as hardness, toughness and the like of the artificial quartz stone slate are effectively improved through optimization and improvement of a raw material formula, matching of different raw materials and improvement of the preparation method, the artificial quartz stone slate has high anti-bacterial ability and lasting anti-bacterial action, and the comprehensive performance of the artificial quartz stone slate is improved.

The invention belongs to the technical field of organic photoelectric materials, and particularly relates to a D(A-Ar)2-type conjugate compound based on dithiophene benzoisoaromatic heterocyclic fusedring as well as a preparation method and application of the D(A-Ar)2-type conjugate compound. The preparation method comprises the following steps: using methyl 2, 5-dibromo-1, 3-dicarboxylate as a central ring nucleus; and preparing organic small-molecule photovoltaic donor materials with a cyclobenzene-containing dithiophene benzoisoaromatic heterocyclic fused ring D(A-Ar)2-type structure through coupling of heterocyclic phenone derivatives, ring-closing reaction and coupling reaction. D(A-Ar)2-type conjugate molecules based on dithiophene benzoisoaromatic heterocyclic fused ring involved in the invention have excellent solubility and stability, wide spectral absorption range and appropriate energy level structure, and are expected to be used as donor materials for organic solar cells.

The invention relates to a 3D chrysanthemum-like Z type Bi2S3@CoO heterojunction composite catalyst as well as a preparation method and application thereof. The preparation method of the 3D chrysanthemum-like Z type Bi2S3@CoO heterojunction composite catalyst comprises the following steps: adding CoO and Bi(NO3)3 into redistilled water, continuously stirring, dropwise adding a Na2S aqueous solution, stirring and reacting, then centrifuging and taking a solid product, repeatedly washing the solid product with redistilled water until the solid product is neutral, drying the solid product, then putting the product into a tubular furnace, and calcining for 2 hours under 250 DEG C to obtain a target product. The degradation rate on tetracycline of Bi2S3@CoO can reach up to 90%, and the degradation rate on aureomycin of Bi2S3@CoO can reach over 70%; the preparation method is simple, convenient and efficient and is low in cost; the prepared composite material has the characteristics of narrowband gap, large specific surface area and high catalytic activity, is excellent in visible light absorption performance, excellent in stability, high in photoelectric efficiency and excellent in photoelectrocatalysis degradation effect on organic matters, and can be applied to the fields of photoelectrocatalysis degradation organic matters and sensors.

Disclosed are compositions, processes, and methods directed to mesoporous carbon nitride materials having high nitrogen content. The mesoporous carbon nitride material has a three dimensional C₃N₅ 3-amino-1,2,4-triazole based mesoporous carbon nitride matrix having an atomic nitrogen to carbon ratio of 1.4 to 1.7, and a band gap of 1.8 to 3 eV.

The invention relates to the field of materials science, especially the indium-phosphorus-nitrogen-bismuth material, a preparation method thereof, a laser and a detector using the indium-phosphorus-nitrogen-bismuth material, and a preparation method for the laser and the detector. The indium-phosphorus-nitrogen-bismuth material comprises an indium phosphide substrate; an indium phosphide bufferinglayer which is disposed on the indium phosphide substrate; and an indium-phosphorus-nitrogen-bismuth body which is disposed on the indium phosphide buffering layer. The chemical formula of the indium-phosphorus-nitrogen-bismuth body is InP<1-x-y>N<x>Bi<y>, wherein x and y are the concentration percentages of N atoms and bismuth atoms, 0<x<11.1%, and 0<y<11.1%. The indium-phosphorus-nitrogen-bismuth material provided by the invention is smaller in energy gap width, is easier to grow and is more stable.