34results about How to "Changing the bandgap width" patented technology

The invention belongs to the preparation fields of a photoelectric material and a thin film solar cell, and discloses a high-orientation antimony selenide thin film and a preparation method therefor, particularly an antimony selenide thin film with high orientation. The high-orientation antimony selenide thin film is a one-dimensional chain-like material; the high orientation refers to the thin film formed by the antimony selenide chin which is grown in a direction of <002>. The preparation method specifically comprises two steps of adopting a thermal evaporation method or other methods to prepare the antimony selenide thin film, and then performing a method for carrying out selenylation (sulfuration) processing. By adoption of the preparation method provided by the invention, the high-orientation antimony selenide thin film can be obtained; a more efficient antimony selenide thin film solar cell is expected to be obtained; and in addition, the preparation method is simple and feasible, and low in cost.

The invention relates to a preparation method of a graphene nanobelt-loaded semi-conductive 3D photocatalytic material. The preparation method comprises dissolving a titanium dioxide precursor in a hydrogen peroxide-ammonium hydroxide mixed solution, stirring the mixed solution until the solution has a yellow color and is clear, adding carbon nitride into the mixed solution, when the solution is turbid, carrying out centrifugation washing, adding deionized water and graphene nanobelts subjected to ultrasonic treatment into the solution, carrying out stirring, carrying out a reaction process in a reactor, centrifuging, washing and drying the reaction product and calcining the dried reaction product in a nitrogen atmosphere to obtain the graphene nanobelt-loaded semi-conductive 3D photocatalytic material. Compared with the prior art, the preparation method has simple processes and effectively improves catalyst activity and photocatalysis performances. Through use of the graphene nanobelt, the graphene nanobelt-loaded semi-conductive 3D photocatalytic material can produce obvious response in a visible light area.

The invention provides a preparation method of a titanium dioxide-mesoporous polymer nano porous composite visible light catalytic material, which comprises the following steps: a. polymerizing azodiisobutyronitrile used as initiator, divinylbenzene used as a crosslinking monomer, 4-vinyl pyridine or 1-vinyl imidazole used as a functional monomer and n-butyl titanate used as a titanium source under solvothermal conditions at 80-140 DEG C for 12-24 hours, thus obtaining a bulk polymer solid; and b. placing the polymer solid product into a reaction kettle, adding a right amount of water, and performing hydrothermal treatment at 150-180 DEG C for 10-24 hours, thus obtaining the titanium dioxide-mesoporous polymer multistage nano porous composite visible light catalytic material. The material preparation method is simple; the obtained photocatalyst has excellent enriching effect and catalytic degradation activity on organic pollutants, especially decabromobisphenol A; and the bulk shape is beneficial to the recycling of the catalyst in the use process.

The invention belongs to the technical field of photocatalytic materials, and particularly relates to a method for preparing an iron-doped graphene oxide titanium oxide nanocomposite modified micro-filtration membrane. GO nanosheets are synthesized through a modification Hummers method, Fe-doped TiO2 nanoparticles are prepared through a sol-gel method and high-temperature calcination, then the GOnanosheets and the Fe-doped TiO2 nanoparticles are mixed with a certain proportion through ultrasonic treatment, a blended solution is prepared through a hydrothermal method, and finally through centrifugation, washing and drying, the iron-doped graphene oxide titanium oxide nanocomposite modified micro-filtration membrane is prepared. The prepared micro-filtration membrane can utilize visible light for photocatalytic degradation, and is high in photocatalytic activity.

The invention discloses a copper doped cerium oxide photocatalyst and a preparation method thereof. The molecular formula of the copper doped cerium oxide photocatalyst is CuxCe<l-x>O<2-x>, in the formula, x is 0.05-0.2. The preparation method comprises the following steps: at the room temperature, dissolving cerous nitrate and cupric nitrate in deionized water, performing ultrasonic stirring for certain time, preparing NH4HCO3 solution or Na2CO3 solution by using deionized water, performing coprecipitation reaction for 30 minutes by using a coprecipitation method through reverse titration and by controlling the temperature to be 70-80 DEG C, after the reaction is completed, cooling to be the room temperature, performing centrifugal separation, washing, drying and calcining the obtained precipitate in sequence, thereby obtaining the copper doped cerium oxide photocatalyst with good photocatalytic performance. The needed production equipment is simple, and the industrialization production is easy to achieve.

The invention relates to a charge storage type insulated gate bipolar transistor and a preparation method thereof, belonging to the technical field of power semiconductors. By improving the charge storage layer of the traditional charge storage type IGBT device, a semiconductor material used for the charge storage layer remote from the drift region has a larger band gap than a semiconductor material used for the charge storage layer close to the drift region, so that the semiconductor materials with different forbidden band widths form the same-type heterojunction at their contact interfaces,thereby forming a potential barrier that prevents minority carriers in the drift region from entering the base region. As a result, the carrier distribution concentration in the drift region is improved, the conductivity modulation effect of the IGBT is enhanced, the forward conduction voltage drop Vceon of the device is reduced, the breakdown voltage of the IGBT is optimized, and the tradeoff between the forward conduction voltage drop Vceon and the shutdown loss Eoff is achieved. Moreover, by adjusting the doping concentration of materials with different bandgap widths in the charge storagelayer and the combination of materials with different bandgap widths, the invention can further optimize the working characteristics of the device.

The invention discloses a preparation method of a viologen compound, belonging to the field of electrochromic materials. The preparation method comprises the following steps of: (1) dissolving 4, 4'-bipyridyl in excess acetonitrile, dissolving 2-bromobutyl phosphonic acid diethyl ester in the excess acetonitrile, further dripping into a 4, 4'-bipyridyl solution, reacting for 24h, washing, filtering and drying to obtain a (1-(diethyl 2-butylphosphonate)-4, 4'-pyridine) bromide solid; (2) dissolving the prepared solid in methanol, further adding alpha, alpha'-dibromo-p-xylene, stirring at constant temperature, washing, filtering, and performing vacuum drying to obtain a 1, 1'-(1,4-phenylene-bis (methylene))-bis-(1'-(diethyl 2-butylphosphonate)-4,4'-pyridine) tetrabromide solid; and (3) dissolving the prepared product in the step (2) in the methanol, adding concentrated hydrochloric acid, stirring at constant temperature, washing, filtering and drying to obtain 1,1'-(1,4-phenylene-bis (methylene))-bis-(1'-(2-butylphosphonic acid)-4,4'-pyridine) tetrachloride. The viologen compound prepared by the preparation method disclosed by the invention can realize rapid changes in color of the electrochromic materials.

The invention relates to an insulated gate bipolar transistor and a preparation method thereof, belonging to the technical field of power semiconductors. On the basis of the traditional charge storagetype IGBT device structure, A heterojunction structure is formed in the base region, thereby forming a potential barrier that prevents minority carriers in the drift region from flowing into the baseregion, thereby greatly increasing the minority carrier concentration near the emitter side in the drift region, The carrier concentration distribution in drift region is improved and the conductivity modulation effect of IGBT is enhanced, which reduces the forward conduction voltage drop Vceon and optimizes the tradeoff between the forward conduction voltage drop Vceon and the shutdown loss Eoffof IGBT. It overcomes the shortcoming that the traditional charge storage layer reduces Vceon and breakdown voltage at the same time. Moreover, the device performance can be further optimized by adjusting the combination of semiconductor materials with different forbidden band widths to form heterojunction structures.

The invention discloses a preparation method of a Fe-BiOBr/MOF-SO3@TiO2 photocatalyst. Bi(NO3)3 5H2O, FeCl3 6H2O, MOF-SO3@TiO2 nanomaterials, NaBr, TiO2 and N-N-dimethylacetamide serve as the main rawmaterials, preparation is conducted by means of an improved solvothermal method and an ultrasonic method, FeCl3 6H2O is added, Fe<9+> is introduced, the Fe<9+> is migrated into a crystal lattice of BiOBr to form a defect, the forbidden bandwidth of the catalyst is changed, and then separation of a photo-induced electron and a hole is promoted, and the oxidation activity is improved. Accordingly,the preparation technology is novel, a good visible light degradation effect is achieved, the cost can be lowered, pollution can be reduced, and the good application prospect and economic benefit areachieved in the aspect of organic pollutant decomposition.

The invention discloses a manufacturing method of an LED epitaxial wafer. By using the method, luminescence area losses can be further reduced, a supplementation layer is increased and growing quality of a quantum well is improved; and a backward voltage is increased, internal electric leakage of a device is reduced, and simultaneously, an In-component gradual-change inclined well layer is used to change a forbidden band width of the well so as to capture more electrons and cavities. Contact areas of the electrons and the cavities are increased. A luminescence area is increased too. Operation speeds of the electrons are reduced and a number of effective electrons which are contacted with the cavities is increased.

The invention provides a Z-mechanism Bi2O3@CeO2 photocatalyst rich in oxygen vacancy, a preparation method and application of same, and belongs to the technical field of photocatalysis. The method comprises the following steps: 1) preparing a reaction solution; 2) preparing a catalyst precursor solution; 3) under the protection of N2, calcining the precursor solution in a tubular furnace at a hightemperature to prepare an intermediate Bi@CeO2; and 4) preparing the Z-mechanism Bi2O3@CeO2 photocatalyst rich in oxygen vacancy. The catalyst is of a globular flower shaped structure by attaching nanosheet-shaped Bi2O3 to globular flower shaped CeO2 particles. The photocatalyst can be applied to degradation of NOx in air under the condition of visible light, is high in degradation rate and longin activity retention time, and the yield of an intermediate product NO2 is low. Products formed by degradation are low in toxicity or non-toxic, so that secondary pollution to the air is avoided.

The invention relates to the technical field of luminescent materials and devices, in particular to a preparation method and application of Zn < 2 + > doped CsPbBr3 nanocrystalline phosphosilicate glass, and the method comprises the following steps: melting uniformly mixed raw materials at a certain temperature to obtain molten glass; pouring the molten glass into a mold for molding, annealing ata certain temperature for a certain time, and cooling to room temperature; and carrying out heat treatment on the product at a certain temperature for 1-10 hours to obtain the Zn < 2 + > doped CsPbBr3nanocrystalline phosphosilicate glass. According to the preparation method disclosed by the invention, the adjustment of the sizes of the CsPbBr3 nanocrystal and the Zn < 2 + > doped CsPbBr3 nanocrystal can be realized, and the band gap of the CsPbBr3 nanocrystal is reduced through Zn < 2 + > doping, so that the spectrum is subjected to blue shift, and blue light is presented. The Zn < 2 + > doped CsPbBr3 nanocrystalline phosphosilicate glass prepared by the method can be used for preparing a white light LED.

The invention relates to a method for preparing a tungsten doped zinc oxide nanosphere through liquid phases. The method comprises four stages of zinc oxide/sodium tungstate sol preparation, low-temperature drying, high-temperature annealing and grinding. Particularly, the tungsten doping proportion is preferably selected, and the preparation process parameters are optimized. The method comprisesthe steps that 2.3g of zinc acetate, and 0g, 0.03464g, 0.06927g, 0.10391g, 0.13854g and 0.17318g of sodium tungstate are dissolved into a mixed solution of 10mL of deionized water and 20mL of ethyl alcohol; stirring is performed for 10min; 1mL of neovaricaine is dripped at 65 DEG C; meanwhile, stirring is performed for 2h to obtain uniform and white sol; aging is performed for 36h at room temperature. The sol is dried for 2h at 60 DEG C; then, annealing is performed for 2h at 600 DEG C under the nitrogen gas protection in a CVD quartz tube; a sample is obtained; grinding is performed for 10min; a photocatalysis material of the tungsten doped zinc oxide nanosphere is obtained. The degradation rate of the product on 15mg/L methylene blue solution under the ultraviolet light irradiation of a300W mercury lamp is studied. The method has the advantages that the operation is simple; the equipment requirements are low; the repeatability is good; the cost is low; the obtained sample has excellent performance of degrading organic dye under the ultraviolet light irradiation.

The invention provides an organic waste liquid treatment material which is characterized by being prepared by the following process: (1) adding sodium tripolyphosphate into a mixed solvent of cyclohexane and n-butyl alcohol, and ultrasonically mixing to form a blending system; (2) adding Bi salt, Fe salt, phosphoric acid and Mo salt in a certain molar ratio into the blending system, and then carrying out water bath reaction at 80-100 DEG C; (3) drying the obtained product, washing with deionized water and ethanol, and drying; and (4) carrying out heat treatment on the product in an air or oxygen atmosphere at the normal butanol degree of 300-500 DEG C, so as to obtain the nanorod-shaped Mo and P co-doped Bi2Fe4O9.

The invention discloses a cerium and tin co-doped fluorphosphate luminescent material. The chemical formula of the luminescent material is Me5-x-y(PO4)3F: x Ce<3+>, ySn<4+>, wherein x represents 0.01-0.05, y represents 0.01-0.06, and the Me represents magnesium ions, calcium ions, strontium ions or barium ions. In an electroluminescent spectrum (EL) of a luminescent film made from the cerium and tin co-doped fluorphosphate luminescent material, quite high luminescent peaks exist in a 450nm wavelength region and a 480nm wavelength region both, so the cerium and tin co-doped fluorphosphate luminescent material can be applied to a film electroluminescent member. The invention also provides a preparation method and an application of the cerium and tin co-doped fluorphosphate luminescent material.

The invention discloses a cut-off carbon nanotube and TiO2 nanotube array heterostructure and a preparation method and device thereof. The preparation method comprises the following steps: controlling reaction conditions to regulate and control the length/diameter size and proportion of a TiO2 nanotube array structure and carbon nanotubes; carbon nano tube and TiO2 nano tube array heterostructures with different packing densities are formed through an electrophoresis method; the obtained series of heterostructures with different structures are prepared into brand-new photovoltaic devices under two conditions of no electrolyte and existence of electrolyte respectively. The average photocurrent density is increased from 16 [mu] A/cm < 2 > of a pure TiO2 nanotube array to 20-23 [mu] A/cm < 2 >; and the efficiency of the device is 0.01%-2%. The device is simple in manufacturing method, low in cost and free of pollution, is a novel structure capable of effectively utilizing sunlight, and widens the application range of TiO2 and carbon nanotubes in the photovoltaic field.