61results about How to "Adjustable bandgap" patented technology

A light emitting device can incorporate a plurality of nanostructures in a light emission layer. The device can include a donor electrode and an acceptor electrode which are light transmissive. At least one of the donor electrode and acceptor electrode can include an inorganic material. The light emission layer can be disposed between each of the donor material and the acceptor material.

The invention relates to a perovskite solar cell and a method for manufacturing the same. The perovskite solar cell comprises an FTO (fluorine-doped tin oxide) transparent conducting glass substrate, an electron transport layer, a light absorption layer, a hole transport layer and a metal electrode. The light absorption layer is made of (C<6>H<5>CH<2>CH<2>NH<3>)<2>(CH<3>NH<3>)<n-1>Pb<n>I<3*n+1> (the n is equal to 1 or 2) materials which are of two-dimensional layered structures. The perovskite solar cell and the method have the advantages that the layered perovskite light absorption layer is manufactured by the aid of a spin coating process, the method is simple and is excellent in film-forming property, the materials of the light absorption layer can be changed along with the layer number n, gaps of the materials can be adjusted, and the materials are excellent in chemical stability and still can keep the excellent layered structures without chemical decomposition after being exposed at high air humidity (50-80%) for 30 days, solar cell prototype devices with excellent and stable performance can be obtained, and the perovskite solar cell and the method are favorable for promoting perovskite solar cell commercialization progress.

The invention discloses a preparation method of a double-sided passivated crystalline silicon solar cell, belonging to the technical field of photovoltaic power generation. The preparation method comprises the following steps of: firstly, respectively carrying out surface precleaning and surface texturing on P-shaped single crystal silicon and a polycrystalline silicon wafer by adopting an alkaline solution and an acid solution; secondly, diffusing by using phosphorus oxychloride as a diffusion source to form a PN junction; thirdly, removing a phosphosilicate glass on the surface of the silicon wafer by adopting a chemical wet method, and etching the edge of the silicon wafer by adopting a plasma; fourthly, preparing a silicon nitride film on the surface of an emitting region of a P-type silicon wafer by adopting a plasma enhanced chemical vapor deposition method; fifthly, preparing a mixed phase film material of hydrogenated microcrystalline silicon and amorphous silicon by adopting a hot filament chemical vapor deposition method, depositing a film at one side of the P-type silicon wafer, and passivating the defects and a dangling bond on the surface of the P-type silicon wafer; and sixthly, sintering a screen printing back electrode and a screen printing positive electrode to form the solar cell. The invention lowers the probability of compounding photo-generated minority carriers on the back surface, enhances the long-wave light quantum efficiency and creates the conditions of transportation and collection of the photo-generated carriers.

The invention relates to a vibration damper for a photonic crystal with an adjustable cell property period array. According to the vibration damper, the influence of a photonic crystal weak joint interface (or interface layer) on a band gap is considered, the controllability of physical and mechanics parameters under magnetorheological elastomers field conditions is utilized, an appropriate mechanism is built, and a controllable cell material physical property and interface layer geometrical parameters are obtained, so that the random vibration control photonic crystal variable band gap range suitable for multiple working condition control structure system obtained in a photonic crystal mechanism is realized, and the vibration damping efficiency of structural vibration control is improved.

The invention discloses a perovskite solar cell introduced with an organic ligand, and a preparation method of the perovskite solar cell. An absorption layer of the perovskite cell is introduced withthe organic ligand, so that a three-dimensional perovskite framework structure becomes a two-dimensional structure through dimensionality reduction, and a perovskite absorption layer structure with aninorganic perovskite layer and two organic ligand layers is formed; the electronic dimension is reduced, so that the band gap of the absorption layer is adjustable; and meanwhile, the crystallizationprocess can be regulated and controlled, namely, the final crystal particle size is controlled, so that the particle size of perovskite is increased, the environment stability of a thin film and a device is enhanced, the dynamic stability of crystals is also improved, and meanwhile, the environmental stability and the thermodynamics stability of the perovskite cell are improved; the structure cancontrol the physical property and the photovoltaic property of the perovskite, which are higher than those of other two-dimensional perovskite solar cells; an idea is provided for preparing the two-dimensional perovskite solar cell with stable performance; and the commercial process of the perovskite solar cell is promoted.

The invention discloses a terahertz emission source based on transition metal chalcogenide and an excitation method. The terahertz emission source comprises a transition metal chalcogenide film and pumping light source. The terahertz emission source has the advantages that fixed incoming excitation pulses are used, the planar central axis of the transition metal chalcogenide film is rotated, and pumping light source laser comes in at 0-90 degrees and excite the surface of the transition metal chalcogenide film to radiate terahertz waves; the transition metal chalcogenide film is used as the terahertz emission source, so that the generated terahertz emission source is high in radiation efficiency; in addition, due to the fact that the film is good in heat conductivity, stable in lattice structure and adjustable in energy band gap, device service life and wide application range are guaranteed, and a two-dimensional terahertz emission source type gap is filled up; by using the transitionmetal chalcogenide film as the terahertz emission source, elliptical polarization terahertz waves can be generated, and the elliptical polarization terahertz waves is significant in molecular chirality spectrum, substance circular dichroism spectrum, polarization imaging and the like.

The invention provides a supported cobalt monatomic catalyst and a preparation method and application thereof. The preparation method comprises the following steps: (1) enabling urea to be subjected to a thermal polymerization reaction to obtain graphitized carbon nitride; (2) reacting the graphitized carbon nitride obtained in the step (1) with cobalt salt to obtain a cobalt and graphitized carbon nitride compound; and (3) carrying out heat treatment on the compound obtained in the step (2) and hypophosphite to obtain the supported cobalt monatomic catalyst. The preparation method is simple, wide in raw material source and high in yield, and has a large-scale application prospect. The supported cobalt monatomic catalyst is a phosphorus-doped graphitized carbon nitride supported cobalt monatomic catalyst, has the characteristics of adjustable band gap, high catalytic activity and high selectivity, and can realize selective oxidation under photocatalysis with high conversion rate; and the catalyst is especially suitable for converting alcohol compounds into aldehyde compounds or ketone compounds through a photo-oxidation catalytic reaction.

The invention provides a synthesis method of a metal nanoparticle asymmetrical single-face inlayed molybdenum disulfide nanosheet. The synthesis method comprises the following steps that 1, a metal salt powder material and molybdenum disulfide powder material are fully grinded and mixed according to the mass ratio of 1:3 to 1:50; 2, the mixed powder is put in flowing air for calcination, metal salt is decomposed to generate metal nanoparticles, the metal nanoparticles are inlayed on a molybdenum disulfide surface, and natural cooling is performed to obtain a complex; 3, the complex is dissolved in a solvent, and a molybdenum disulfide stratified material is stripped under the ultrasonic effect of a water bath, then the complex is centrifuged to obtain supernatant liquid, the supernatant liquid is centrifugally separated to obtain the metal nanoparticle inlayed molybdenum disulfide nanosheet. The molybdenum disulfide nanosheet is inlayed with the metal nanoparticles on one single face, the metal nanoparticles are narrower and adjustable in size distribution, accordingly the band gap of molybdenum disulfide is adjustable and controllable, the symmetry of molybdenum disulfide is destroyed, accordingly its electronic structure is changed, and meanwhile the number of active sites is increased.

The invention relates to a method for preparing a two-dimensional semiconductor alloy. The general formula of the two-dimensional semiconductor alloy is MoS2(1-x)Se2x, wherein x is more than 0 and less than or equal to 1. The method comprises: heating molybdenum sulfide and molybdenum selenide placed in quartz tubes respectively in an oxygen-free environment till volatilizing, keeping a volatilization temperature, and performing chemical vapor deposition on the volatilized molybdenum sulfide and molybdenum selenide on a silicon substrate under the action of introduced protective gas flow to form the two-dimensional semiconductor alloy material. The provided two-dimensional semiconductor alloy MoS2(1-x)Se2x can realize continuous adjustment of band gaps by adjusting the value of xl and the band gap adjustment of the two-dimensional semiconductor alloy MoS2(1-x)Se2x is realized by controlling the volatilization quantity of the molybdenum sulfide and the molybdenum selenide.

The invention relates to the field of controlled preparation of semi-conductivity single-walled carbon nanotubes, in particular to a method for preparing a narrow-band-gap-distribution high-purity semi-conductivity single-walled carbon nanotube through a partial-carbon-coated metal catalyst. By means of a segmented copolymer self-assembly method, a uniform-size copolymer thin film coated metal anion nanometer cluster is prepared; single-dispersion partial-carbon-coated metal catalyst nanoparticles are obtained by controlling the annealing, oxidizing and reducing conditions of solvents; nitrogen serves as in-situ etching gas, and the narrow-band-gap-distribution high-purity semi-conductivity single-walled carbon nanotube directly grows. The content of the semi-conductivity single-walled carbon nanotube is larger than 98%, and the band gap difference is 0.05 eV at least and can be adjusted. The direct controllable growth of the narrow-band-gap-distribution high-purity semi-conductivity single-walled carbon nanotube is achieved, the bottleneck of control and preparation of the narrow-band-gap-distribution high-purity semi-conductivity single-walled carbon nanotube at the present stage is broken through, and it is proved that the nanotube is an ideal tunnel material for establishing a thin film field effect transistor.

The invention provides a perovskite sheet-based light-emitting device and a preparation method thereof. The method is convenient to process and simple in preparation; and the device is assembled by growing band gap-adjustable perovskite sheets. The method comprises the steps of (1) obtaining a monocrystalline or polycrystalline perovskite crystal of a corresponding light-emitting wavelength by controlling the halogen ion doping amount; (2) slicing the obtained perovskite crystal to obtain large-area perovskite sheets of which the area is greater than 200 mm<2> and the thickness is smaller than 1 mm; and (3) taking the large-area perovskite sheets as active layers of the light-emitting device to obtain the light-emitting device. On the basis of preparation of the large-sized color-adjustable monocrystal or polycrystal perovskite crystal, the perovskite sheets are prepared by employing a crystal cutting process; and perfect cutting of the crystal can be achieved by controlling the roughness and the movement speed of a cutting line in the cutting process. By the cutting process of the perovskite crystal, production of a high-quality perovskite wafer is facilitated and preparation of a high-quality perovskite single crystal device is facilitated.

The invention provides a black-phosphorus quantum-dot photocatalyst with adjustable band gaps, a preparation method and application thereof. The black-phosphorus quantum-dot photocatalyst is prepared by a simple heating reaction method, the sizes and the band gaps of black-phosphorus quantum dots are regulated and controlled by changing a reaction solvent, and further the photocatalytic property of the black-phosphorus quantum-dot photocatalyst is enhanced. The researched black-phosphorus quantum dots can be effectively applied in organic pollutants such as photocatalytic-degradation rhodamine B and the like. The black-phosphorus quantum-dot photocatalyst has the advantages of no pollution, low cost, stability and simple preparation process and the like.

The invention provides an organic photodiode, an X-ray detector and a preparation method of the X-ray detector. The organic photodiode and an organic thin film transistor are prepared by adopting a solution method, so that low-cost equipment can be adopted for production, the preparation process is simplified, and the cost is saved. The organic photodiode and the organic thin film transistor are combined, which is suitable for preparing the flexible X-ray detector. In the organic photodiode, the band gap of an organic active layer is adjustable, so that the external quantum efficiency of the organic photodiode can be improved, and the sensitivity of the X-ray detector is further improved. In the organic thin film transistor, the carrier mobility of an organic channel layer is relatively high, so that the switching rate of the organic thin film transistor can be improved.

The invention discloses a method for producing ZnSO alloy film with an adjustable sulfur-doped growth band gap, which uses a pulse laser deposition method. A target material is produced by mixing pure zinc oxide and pure zinc sulfide powder for hydraulic forming to obtain a ceramic target, wherein mole content of zinc sulfide is 10 to 40%; the target material is arranged in a growth chamber of a pulsed-laser deposition device, wherein the degree of vacuum is 1*10(-4) to 1*10(-3)Pa, the laser frequency is 3 to 10Hz, the growth temperature is from 300 to 500 DEG C, a ZnSO alloy film with an adjustable band gap is grown on a substrate. A real time doping can be realized according to the method provided in the invention, the doping concentration can be controlled by regulating the growth temperature and mole content of sulfur in the target material. Method for producing the ZnSO alloy film with adjustable sulfur-doped growth band gap provided in the invention has the advantages of good optical performance, repeatability and stability.

The invention relates to a superhard semiconductor amorphous carbon block material and a preparation method thereof. The method includes the following steps: (1) prefabricating C60 fullerene into a columnar blank body; (2) loading the obtained columnar blank body into a hexagonal boron nitride crucible, and then loading into a high-temperature high-pressure assembly block; (3) placing the assemblyblock in high-temperature and high-pressure synthesis equipment for high-temperature and high-pressure treatment; and (4) acquiring the superhard semiconductor amorphous carbon block material after the treatment is completed. According to the preparation method of the superhard semiconductor amorphous carbon block material, the C60 fullerene powder is taken as a raw material, a high temperature and high pressure test is utilized, a phase change behavior of the C60 fullerene under high pressure is explored by regulating a relationship between temperature and pressure, and the amorphous carbonblock material with high hardness or superhard hardness, compactness and semiconductor properties is synthesized, so that the material has a wide application prospect.

The invention provides an Au / Bi24O3Br10 composite photocatalyst and a preparation method thereof, and relates to the technical field of the photocatalysis. The preparation method comprises the following steps: preparing BiOBr through a chemical precipitation method, roasting BiOBr to obtain sheet Bi24O3Br10; dispersing Bi24O31Br10 into water, adding a chloroauric acid solution, and then performingnitrogen aeration and xenon lamp radiation treatment to obtain a suspension; separating, washing and drying to obtain the Au / Bi24O31Br10 composite photocatalyst. The uniform Au particles are loaded on the sheet Bi24O31Br10 through chemical precipitation, high-temperature calcination and photodeposition methods; the preparation process is simple; the particle size is controllable; the band gap ofthe photocatalyst is adjustable; and the absorption range on the visible light by the photocatalyst is effectively improved. The metal particles are loaded through the photodeposition method, and thephotocatalysis efficiency is improved.

The invention relates to a method for adjusting a band gap of a vanadium dioxide film. The method realizes vanadium dioxide film band gap adjustment by adjustment of a band gap of vanadium dioxide for preparation of a vanadium dioxide film. The method comprises the following steps of preparation of vanadium dioxide powder having adjustable band gap: adding a specified amount of an adopted element in a vanadium dioxide powder hydrothermal method preparation so that the obtained vanadium dioxide powder having a chemical composition of V1-xMxO2 has an optical band gap continuously adjustable in a range of 0.6-4.0eV, wherein x is greater than 0 and is less than or equal to 0.5 and the adopted element M represents magnesium, aluminum, lanthanum, zirconium, gallium, niobium, tin, tantalum, manganese, nickel, chromium, zinc, titanium, tungsten, antimony, bismuth, indium or iron, and preparation of a vanadium dioxide film of which band gap is adjustable: coating a substrate with the band gap-adjustable vanadium dioxide powder dispersion liquid to obtain the band gap-adjustable vanadium dioxide film having an optical band gap continuously adjustable in a range of 0-4.0eV.

The invention provides a method for quickly extracting purified benzoylurea pesticide residues from fruits and vegetables, and relates to the technical field of food detection. The detection method comprises the following steps of 1 extracting, wherein a homogeneous fruit and vegetable sample is weighed and put into a centrifuge tube, extraction is conducted by adding acetonitrile, then sodium chloride and magnesium sulfate are added, and supernatant liquid is obtained; 2 purifying, wherein the supernatant liquid is taken to be transferred into a centrifuge tube containing C18 and a tungsten disulfide nanometer material to be purified and then filtered with a 0.22-micrometer organic micropore filtering membrane to obtain purified liquid; and 3 measuring. According to the detection method,extraction is conducted by adopting the organic solvent acetonitrile, dewatering is conducted by adopting sodium chloride and magnesium sulfate, purifying is conducted by adopting C18 and the tungstendisulfide nanometer material, a large number of pigments in the fruits and vegetables or proteins in the plant source sample can be effectively removed, and then the purposes of reducing chromatographic analysis interference and improving the measuring accuracy are achieved.

The invention relates to a method for preparing sulfur-doped molybdenum dioxide nanosheets with adjustable shapes and band gaps. The method has the advantages that a method for adjusting band gaps through carrying out sulfur doping on molybdenum dioxide nanosheets is researched to obtain the nanosheets with different band gaps, then, the nanosheets can be applied to the manufacturing of micro / nanoelectronic devices, and electronic devices with excellent performance are obtained. The method has the advantages that the disadvantage that band gaps of molybdenum dioxide are oversized is overcome,and band gaps of the prepared molybdenum dioxide nanosheets are adjusted; and in order to achieve the aim, a molybdenum dioxide nanosheet band gap adjusting method is disclosed, and the sulfur dopeddegree of the nanosheets is adjusted through controlling a ratio of precursor sulfur powder to molybdenum trioxide powder and a growth temperature. Finally, the molybdenum dioxide nanosheets of different band gaps are obtained. The method disclosed by the invention is simple in processing steps and easy in reaction condition control and is adaptable to industrial production; and the product has excellent electrical properties and has a huge application value in the field of the micro / nano electronic devices.

The invention relates to a preparation method of a gallium nitride epitaxial structure based on a molybdenum disulfide-graphene composite buffer layer, and belongs to the technical field of photoelectronics. The preparation method comprises the steps of performing cleaning on a silicon substrate; enabling a molybdenum disulfide-graphene composite layer to be grown on the silicon substrate; enabling an aluminum nitride layer to be grown on the molybdenum disulfide-graphene composite layer by adopting an atomic layer deposition method; and enabling a gallium nitride layer to be grown on the aluminum nitride layer by adopting a metal organic chemical vapor deposition method, and the like. By adopting the molybdenum disulfide-graphene composite layer as the buffer layer between the silicon substrate and the GaN epitaxial layer, the problems of defect malposition, cracks and the like caused by high lattice mismatch and thermal mismatch between the substrate and the epitaxial layer can be solved, the stress between the substrate and the epitaxial material can be lowered effectively, and the GaN epitaxial layer quality is improved.

The invention discloses a preparation method of a dopamine sensor material based on Prussian blue / molybdenum selenide, which comprises the following steps: carrying out hydrothermal reaction on sodiummolybdate and selenium powder under the action of sodium borohydride to obtain a two-dimensional layered material molybdenum selenide, and reducing Fe < 3 + > into Fe < 2 + > to promote the generation of Prussian blue, thereby obtaining the Prussian blue / molybdenum selenide composite material, then dispersing the composite material onto the activated graphite felt; the invention further providesa product obtained according to the method and application. The PB / MoSe2 / GF electrochemical sensor prepared by the method has rapid, sensitive and high-selectivity electrochemical response to a targetmolecule dopamine; the method can be used for determining human urine and fetal calf serum, and the recovery rate range of a standard addition method is 97.699.2%.

The present invention relates to the field of controllable preparation of semiconducting single-walled carbon nanotubes, specifically a method for preparing narrow band gap distribution and high-purity semiconducting single-walled carbon nanotubes by partially carbon-coating a metal catalyst. A block copolymer self-assembly method is used to prepare uniformly sized copolymer films coated with metal anion nanoclusters; by controlling solvent annealing, oxidation, and reduction conditions, monodispersed, partially carbon-coated metal catalyst nanoparticles are obtained; and then Hydrogen is an in-situ etching gas that directly grows narrow band gap distribution and high-purity semiconducting single-walled carbon nanotubes. The content of semiconducting single-walled carbon nanotubes is greater than 98%, and the band gap difference is at least 0.05eV and is adjustable. The invention realizes the direct controllable growth of narrow band gap distribution and high-purity semiconducting single-walled carbon nanotubes, breaks through the bottleneck of the current controlled preparation of high-purity, narrow band gap distribution semiconducting single-walled carbon nanotubes, and confirms that it is an ideal method for constructing thin film field effects. Ideal channel material for transistors.

The invention relates to a preparation method of a flower-like twin crystal phase Zn<0.2>Cd<0.8>S photocatalytic material. The method comprises the following steps: sequentially adding Zn(NO3)<2>.6H2Oand Cd(NO3)<2>.4H2O into deionized water, and stirring until the solution is clear and transparent, thereby obtaining a mixed solution; (2) adding CH4N2S into the mixed solution, stirring for 5-10 minutes, transferring the mixture into a reaction kettle after the CH4N2S is completely dissolved to be clear and transparent, and adding water into the reaction kettle for reaction; 3) alternately washing the product after the reaction with distilled water and ethanol; and 4) after washing, drying the product to obtain the flower-like twin crystal phase Zn<0.2>Cd<0.8>S photocatalytic material. TheZn<0.2>Cd<0.8>S photocatalytic material with the flower-shaped twin-crystal phase structure is synthesized by utilizing a simple one-step hydrothermal method, so that a new morphology is provided forZnxCd<1-x>S, controllable preparation of the morphology can be realized, and very high photocatalytic water decomposition hydrogen production efficiency is obtained. The preparation method of the catalytic material is simple, controllable, environment-friendly and easy for large-scale preparation, and has important further industrial development and application prospects.

The invention discloses a preparation method of zinc nitride thin film. The preparation method comprises following steps: (1) a substrate is placed in a reaction chamber of an atomic layer deposition apparatus; (2) a zinc-containing precursor source is delivered into the reaction chamber of the atomic layer deposition apparatus so that the zinc atoms in the zinc-containing precursor source are absorbed by the surface of the substrate; (3) a nitrogen-containing precursor source is delivered into the reaction chamber of the atomic layer deposition apparatus, and then is ionized using plasma, or a nitrogen-containing precursor source which is ionized using plasma is delivered into the reaction chamber of the atomic layer deposition apparatus, so that a part of the nitrogen atoms in the ionized nitrogen-containing precursor source are precipitated, and nitrogen-zinc covalent bonds are formed by the precipitated nitrogen atoms with the zinc atoms on the surface of the substrate; and (4) the step (2) and the step (3) are repeated, so that layer by layer growth of the zinc nitride thin film is realized. According to the preparation method, the nitrogen source is delivered into an atomic layer deposition system using the plasma; and various high-quality zinc nitride thin films with adjustable band gap are obtained by adjusting chamber temperature, vacuum degree, circulating period, conditions of the plasma, and the like.

The invention relates to a preparation method of a perovskite solar cell with a GaN semiconductor material as a dual-function layer, and the method comprises the steps: carrying out high-temperature annealing on a substrate to obtain a porous GaN / n-GaN single-crystal substrate; sequentially subjecting the porous GaN / n-GaN single crystal substrate to oxygen plasma vacuum treatment, perovskite light absorption layer coating, hole transport layer coating and electrode evaporation. According to the method, a porous GaN / n-GaN single crystal is used as a dual-functional-layer cathode structure of the perovskite solar cell, is used as a transparent conductive layer and an electron transport layer, and does not have an independent conductive glass layer; and the porous structure of the porous GaN single crystal provides an extended interface contact area with the perovskite light absorber, and shows high light transmittance in a visible spectrum. As the interface with the perovskite is enlarged, the light collection effect is enhanced, and effective carrier extraction is provided. Meanwhile, the porous GaN single crystal is used as the electron transport layer, so that more active positions can be provided, and the light absorptivity can be improved.

The invention relates to a preparation method of nano-nickel oxide. The method comprises the following steps: (1) mixing oleic acid with an octadecene solvent, stirring and heating, adding nickel acetylacetonate, and stirring under the heating condition so as to obtain a light green mixed solution; (2) mixing oleylamine with a surfactant, adding the obtained mixture into the light green mixed solution, and stirring under the heating condition so as to obtain a precursor of the product; (3) carrying out heat preservation on the precursor of the product at 200-220 DEG C for 6-10h, taking out andthen naturally cooling to the room temperature to obtain a gray-green nickel oxide solution; (4) pouring a centrifugation solution into the gray-green nickel oxide solution, centrifuging, removing supernatant and leaving bottom precipitate, adding a cleaning solution into the precipitate, dispersing the precipitate in the clean solution, and washing repeatedly to obtain the nano-scale nickel oxide. The preparation method is low in price of used raw materials and simple in experimental operation, does not require a harsh reaction environment, does not produce toxic gas, is simple in purification, and can be used for rapidly obtaining the nano-nickel oxide.

The invention belongs to the field of transistor devices, and discloses an organic field effect transistor device and a preparation method thereof. The preparation method comprises the following steps: preparing a covalent triazine organic framework nanosheet dispersion liquid from a covalent triazine organic framework material through an electrochemical stripping method, and standing; the covalent triazine organic framework nanosheet dispersion liquid is injected to the liquid level of ultrapure water drop by drop, a SiO2 / Si substrate penetrates through the interface of the covalent triazine organic framework nanosheet and the ultrapure water, and the SiO2 / Si substrate containing the covalent triazine organic framework nanosheet is obtained; and sequentially evaporating a chromium layer and a gold layer on the SiO2 / Si substrate containing the triazine covalent organic framework nanosheet by using a vacuum thermal evaporation coating machine to obtain the organic field effect transistor device. The application range of an organic field effect transistor device prepared according to the covalent triazine organic framework material can be widened.

The invention provides a gallium oxide energy band regulation-based homojunction photoelectric detector and a preparation method thereof. The homojunction photoelectric detector comprises an insulated substrate, the substrate (1) is sequentially provided with an amorphous Ga2O3 film and a beta-phase Ga2O3 film, and the amorphous Ga2O3 film and the beta-phase Ga2O3 film are both provided with contact electrodes. Aiming at the problem that Ga2O3 cannot realize stable p-type doping to limit the preparation of the homojunction photoelectric detector, the invention provides a method for preparing the homojunction photoelectric detector by regulating and controlling the amount of oxygen in the growth process to change the gallium oxide band gap and utilizing the gallium oxide with two different band gaps, so the problem of p-type doping of Ga2O3 during the preparation of the homojunction photoelectric detector is solved; and a foundation is laid for energy band regulation and control of Ga2O3 and preparation and research of a high-performance Ga2O3 homojunction photoelectric detector.

The invention discloses a preparation method of a large-sized mixed halogen methylamine lead-bromine-chlorine crystal. The preparation method comprises the following steps: step S1, stirring a monomethylamine water solution and a hydrobromic acid water solution, and drying by distillation; step S2, stirring a monomethylamine water solution and hydrochloric acid, and drying by distillation; step S3, dissolving PbBr2 with CH3NH3Br and dissolving PbCl2 with CH3NH3Cl into DMF and DMSO solvents to obtain a CH3NH3Pb(Br1-xClx)3 mother liquor; and changing the molar ratio of PbBr2 to PbCl2 to obtain CH3NH3Pb(Br1-xClx)3 mother liquor with different x values; and step S4, raising the temperature of the CH3NH3Pb(Br1-xClx)3 mother liquor to be 95 to 105 DEG C, maintaining a constant temperature until the crystal is separated out, and taking out the crystal when the size of the crystal is not increased any longer. The CH3NH3Pb(Br1-xClx)3 crystal with different halogen proportions can be obtained by changing the proportion of raw materials.