35results about How to "Strong quantum confinement effect" patented technology

A supersonic chemical preparation method for grapheme quantum dots relates to a preparation method for grapheme quantum dots, and especially relates to a method for preparing a grapheme quantum dot solution with the characteristics of good monodispersity and luminescence performance using a simple and environmentally friendly process with cheap carbon black or graphite powder as the raw material. The preparation method provided in the invention is characterized by adding a dispersant into carbon black or graphite and obtaining grapheme quantum dots under the action of supersonic wave. The grapheme quantum dot solution prepared in the invention has the characteristics of luminescence, monodispersion, water-solubility, etc.

The method includes following steps: firstly alumina molding board is made by using electrochemical method;the molding board with highly ordered pore space structure is transplanted to semiconductor base plat; the natural quantum dot of nano-silicon is grown on the semiconductor base plate through the pore of the molding board by using PECVD; finally the aluminum molding board will be removed by using wet chemical method. The artificial quantum dot obtained by the invention has following features: average diameter is 30-50 nanometers; height is 20-30 nanometers; separation is 100 nanometers; area density is over 1X1010 /cm2;a plenty of silica natural quantum dots whose diameter are from 3-6 nanometers are embedded into each artificial quantum dot.

The invention discloses In-doped ZnO monodisperse nano granules and a synthesizing method thereof. The nano granules have hexagonal wurtzite structures, and the diameters of the granules are 1 to 100 nanometers. The synthesizing method comprises the following steps of: mixing fatty acid zinc, fatty acid indium and high-boiling organic solvent and putting the mixture into a reaction flask, heating the mixture to between 50 and 200 DEG C with magnetic stirring, pumping vacuum and removing water vapor and oxygen in the reaction system, heating the mixture to between 200 and 350 DEG C under the inert protective atmosphere, quickly injecting stearyl alcohol of 100 to 250 DEG C into the reaction flask, preserving the heat for 1 to 1,000 minutes, and performing centrifugal separation on the mixture to obtain the In-doped ZnO nano granules. The synthesizing method has the advantages of simple preparation process, low cost, good repeatability and easy industrialized production; and the obtained nano crystal has excellent photoelectric performance and is expected to be applied in many fields of flexible display, transparent electrodes, ultraviolet detection and the like.

The invention discloses an UV-LED with a quantum dot EBL, comprising a sapphire substrate, an A1N nucleating layer, a non-doped u type A1GaN buffer layer, an n type A1GaN layer, an A1xGa1-xN/A1yGa1-yN quantum well active region, a p type A1N/A1GaN quantum dot EBL, a p type A1GaN layer and an ITO conductive layer. An n type ohmic electrode is lead out on the n type A1GaN layer, and a p type ohmic electrode is lead out on the ITO conductive layer. The UV-LED with a quantum dot EBL employs the p type doping layer of self-assembly A1N/ A1GaN quantum dots as the EBL and a hole injection layer, which can effectively inhibit electrons from overflowing out of an active region, enhance the efficiency of hole injection to the active region, and thereby increase the carrier composite efficiency in the active region; in addition, A1N is used as the EBL to replace the A1GaN commonly used in blue LED, which can more effectively reduce UV absorption by the EBL, and increase UV-LED luminous efficiency.

The invention belongs to the technical field of electroluminescent materials, and discloses a FAX-modified metal halogen perovskite quantum dot and a preparation method and application thereof. The preparation method comprises the following steps of dissolving a metal halide BXy and formamidine hydrohalates FAX into a long-chain ligand, so as to obtain a precursor solution; injecting a rubidium source and/or a cesium source to react, adding a precipitating agent to precipitate the product, separating, and dispersing into an organic solvent, so as to obtain the FAX-modified metal halogen perovskite quantum dot solution. The prepared FAX-modified metal halogen perovskite quantum dot has the advantages that the particle size is small, the particle size is controllable, the size distribution is narrow, the yield rate of solid-state film fluorescent quantum dot is high, and the like; the great application prospect is realized in the high-efficiency blue light and white light electroluminescence fields.

The invention discloses a method for preparing silicon-nanoparticle-containing silicon nitride thin films, which comprises the following steps: (1) cleaning a p-type monocrystalline silicon substrate; (2) preparing silicon-enriched non-stoichiometric silicon nitride thin films on substrates by a plasma enhanced chemical vapor deposition technique; and (3) placing the prepared silicon nitride thin films in a quartz furnace, and annealing at a high temperature of 750 to 800 DEG C by using nitrogen as a protective gas, namely directing heating a quartz tube annealing furnace to 750 to 850 DEG C, keeping the temperature for 8 to 12 minutes, and cooling to room temperature through the self-radiation of the quartz tube annealing furnace without any addition cooling measures. And after the non-stoichiometric silicon nitride thin films undergo high-temperature annealing, silicon nanoparticles are embedded in silicon nitride thin films through a phase separation process. The silicon nanopartiles embedded in the silicon nitride thin films are mainly characterized by uniform silicon nanoparticle size, high order, strong quantum confinement effect and simple preparation process.

The invention discloses a preparation method of a PVA film used for a polaroid. The preparation method comprises the steps of mixing PVA power with a plasticizer, then uniformly mixing water-soluble graphene quantum dots into the mixture, pouring the mixture of the three materials into a mixed solvent composed of methanol and distilled water, mixing, dissolving and stirring the mixture at a temperature of 70-90 DEG C for 6-12h to form a mixed solution, subjecting the mixed solution to standing, defoaming and film formation, and carrying out water washing and swelling, dyeing, extension and correction on the mixed solution to obtain polarized properties. The invention further discloses a polaroid, which is prepared by laminating the PVA film doped with the graphene quantum dots, a TAC film, a protective film and an pressure sensitive adhesive; and the addition of the graphene quantum dots can effectively prevent a ''blue leakage'' phenomenon, and improve the heat and humidity resistance of the polaroid.

The invention relates to a method of preparing a graphene quantum dot. The method is mainly characterized by comprising the following steps: preparing a graphene mixed thin film by virtue of a radio-frequency magnetron sputtering technology; diluting by use of diluted hydrochloric acid; filtering and extracting by virtue of a dialysis membrane to obtain the graphene quantum dot with higher quantum yield. The method is very simple to operate and environment-friendly, and the quantum dot obtained is very high in quantum yield. The particle size of the graphene quantum dot can be adjusted by changing the target material mixing proportion and the sputtering power, so that the graphene quantum dot has potential for large-scale preparation and wide application prospect.

The invention discloses a lead telluride nano rod with a uniform size, and a preparation method and applications thereof. According to the preparation method, a short chain organic acid (trans-2-decenoic acid) and lead oxide are combined to form a lead precursor; tri(diethylamino)phosphine and elemental tellurium are combined to form a tellurium precursor; the lead telluride nano rod with a uniform size is synthesized by regulating the reaction temperature and the ratio of the lead precursor to the tellurium precursor and adopting a heat injection method; the diameter of the nano rod is 2-5 nanometers, the length of the nano rod is 10 to 60 nanometers; the electronic belt of the nano rod is anisotropic, and the nano rod has a strong quantum confinement effect. The provided lead telluride nano rod can be well dissolved in an n-hexane solvent and has the advantages of wider application range and user-friendliness. In an ultraviolet visible-near infrared absorption spectrum, the characteristic absorption peaks of the lead telluride nano rod are in a range of 400-550 nm; and the nano rod has special optical properties and thus can be applied to the fields such as solar battery, photoelectric detector, thermoelectric devices, and the like.

The invention provides a preparation method of an ultra-fine WO3 nanowire. The ultra-fine WO3 nanowire is prepared by virtue of a modified solvothermal method. The method comprises the following steps: weighing 0.05-0.2g of Na2WO4.2H2O and 0.1-0.4g of (NH4)2SO4, dissolving Na2WO4.2H2O and (NH4)2SO4 in 6mL deionized water, adding 2mL of 0.1-0.3mol/L hydrochloric acid solution, and stirring and mixing all ingredients uniformly, thereby obtaining a solution A; taking 5mL of cyclohexane and 0.4g of an organic additive, uniformly mixing cyclohexane with the organic additive so as to obtain a solution B; mixing solution B with the solution A to obtain an emulsion mixture, performing reaction on the emulsion mixture in a high-pressure reaction kettle at a temperature of 150-200 DEG C for 24 hours, and performing extraction, washing and drying, thereby obtaining the ultra-fine WO3 nanowire. The preparation method is low in cost, simple and convenient to operate, realizable based on one step and high in productivity; the prepared ultra-fine WO3 nanowire has relatively high photocatalysis activity and can be used for photocatalytic degradation of organic pollutants.

The invention provides a cobaltosic oxide quantum dot and a preparation method thereof. The preparation method includes: using short-chain alcohol as surfactant to wrap hexahydrate cobalt nitrate so as to form settled solution A, using long-chain alcohol as solvent to be well mixed with settled solution A so as to form cobalt nitrate reverse micelle solution, subjecting cobalt nitrate reverse micelle solution to microwave reaction to promote hydrolysis and purification of cobalt nitrate, and separating materials after microwave reaction to obtain the cobaltosic oxide quantum dot. The cobaltosic oxide quantum dot prepared by the method is 3-4 nanometers in particle size, has evident quantum confinement effect, can be well dispersed in water to form colloid, and is capable of generating hydrogen and oxygen by resolving pure water according to standard mole ratio 2:1 under visible light without load and mixing. The cobaltosic oxide quantum dot is also applicable to fields of fluorescopy, electrocatalysis, chemical catalysis, super capacitors and novel batteries.

The invention specifically relates to a deep ultraviolet LED based on AlGaN. The deep ultraviolet LED orderly comprises a substrate, a N-type layer, a first barrier layer, a quantum well active area,an insert layer, a second barrier layer and a P-type layer from bottom to top, and further comprises n-type ohmic electrode derived from the N-type layer and a p-type ohmic electrode derived from theP-type layer. Two barrier layers are arranged at two sides of the quantum well active area, so that the deep ultraviolet LED has strong quantum limiting effect on the carrier, and can effectively prevent the hole from overflowing the active area, and can block the electronic current leakage, and the compounding efficiency at the active area by the carrier is improved. Furthermore, the capacity ofblocking the electronic current leakage by the second barrier layer can be greatly improved through the arrangement of the insert layer.

The invention relates to the technical field of a semiconductor photoelectronic device, in particular to a novel AlGaN-based ultraviolet light emitting diode. The novel AlGaN-based ultraviolet light-emitting diode comprises a tube body, wherein a sapphire substrate, a AlN nucleating layer, a non-doped u-type Al<x1>In<y1>Ga<1-x1-y1>N buffer layer, an n-type Al<x2>In<y2>Ga<1-x2-y2>N layer, a Al<x3>In<y3>Ga<1-x3-y3>N/Al<x4>In<y4>Ga<1-x4-y4>N quantum well active region, a p-type NiO/Al<x5>In<y5>Ga<1-x5-y5>N superlattice structure electron blocking layer, a p-type Zn<z1>Mg<z2>Ni<1-z1-z2>O layer and an indium tin oxide transparent conductive layer are sequentially arranged in the tube body from bottom to top, a p-type ohmic electrode is led out of the indium tin oxide transparent conductive layer, and an n-type ohmic electrode is led out of the n-type Al<x2>In<y2>Ga<1-x2-y2>N layer. In the novel AlGaN-based ultraviolet light emitting diode, the forbidden bandwidth and the lattice constant can be independently adjusted by the AlInGaN material, the crystal quality of an epitaxial layer is effectively improved, the p-type NiO/Al<x5>In<y5>Ga<1-x5-y5>N superlattice structure has a high quantum limitation effect on a carrier, the p-type Zn<y2>Mg<y2>Ni<1-y2-y2>O is used for improving the combination efficiency of the carrier in the active region, the sapphire substrate material on a r surface, an m surface or an a surface is a non-polarity or semi-polarity AlGaN material, the separation of electron and hole wave functions in a space is reduced, and the radiation combination efficiency of the carrier is improved.

The invention discloses a bismuth tungstate heterojunction composite material loaded with copper indium quantum dots as well as a preparation method and application thereof. The composite material is a sulfur indium copper quantum dot-modified bismuth tungstate heterojunction. The preparation method comprises the following preparation steps: mixing and stirring homemade sulfur indium copper quantum dots and a bismuth tungstate flower-like multi-stage structural material in a chloroform solution, performing ultrasonic treatment, heating till complete solvent evaporation and calcining a dried mixture under a nitrogen atmosphere to obtain the sulfur indium copper quantum dot-modified bismuth tungstate heterojunction composite material. The preparation method disclosed by the invention uses the lowly-toxic sulfur indium copper quantum dots to replace traditional cadmium or lead-containing quantum dots, so that the synthetic process is green and environment-friendly; the activity of a synthesized composite photo-catalyst is enhanced, so that the synthesized composite photo-catalyst can be used as a volatile organic pollutant photo-catalyst.

The invention provides a superlattice material embedded with quantum wires, a preparation method of the superlattice material, an infrared band luminescent material and a detector. The superlattice material embedded with the quantum wires comprises at least one InAs/GaSb layer and at least one single substance layer which are arranged in a stacked mode. The InAs/GaSb layer comprises an InAs part and a GaSb part, and the single substance layer comprises InAs or GaSb; the InAs portions and the GaSb portions are alternately arranged and have different widths along the arrangement direction. The preparation method of the superlattice material embedded with the quantum wire comprises the step of sequentially growing the InAs/GaSb layer and the single substance layer on the substrate according to the structure. An infrared band light emitting material includes a superlattice material in which quantum lines are embedded. A detector comprises an infrared band luminescent material. According tothe superlattice material embedded with the quantum lines, the quantum lines are introduced into the II-type superlattice to form a line superlattice composite structure, the working temperature of adevice can be improved, and the photoelectric property of the material is improved.

The invention discloses a perovskite thin film and a preparation method and application thereof. The preparation method of the perovskite thin film comprises the following steps of 1) mixing CsI, CsBrand PbI2 to prepare a perovskite precursor solution, 2) preparing an ethyl ammonium iodide solution, and 3) mixing the perovskite precursor solution and the ethyl ammonium iodide solution, forming afilm, and annealing to obtain the perovskite thin film. Ethyl ammonium iodide is added into the perovskite precursor solution, then film forming is performed, inorganic perovskite crystals with very small particle sizes can be formed under the passivation effect of the ethyl ammonium iodide, and then the perovskite thin film with low defect state density, small grain size and high exciton bindingenergy is prepared.

The invention discloses a resonant cavity, a laser unit, a laser and a laser radar. The resonant cavity comprises a first reflecting mirror and a second reflecting mirror which are oppositely arranged at an interval; the active structure is positioned between the first reflecting mirror and the second reflecting mirror; the active structure comprises one or more first active regions and one or more second active regions, the material of the first active regions has tensile strain, and the material of the second active regions has compressive strain. The second active region with compression stress has higher gain and can regulate and control a band gap so as to adjust a working wave band, and the first active region with tensile strain can release the compression stress introduced by the second active region so as to prevent stress accumulation and avoid stress release; through the arrangement of the first active region and the second active region, the gain of the active structure can be ensured, stress balance can be realized, the generation of structural defects can be inhibited, the quality of the resonant cavity can be improved, the external quantum efficiency and power can be improved, and the reliability of the device can be improved.

The invention discloses a light-emitting diode and laser of a p-GaN/ZnO-based multi-quantum well/n-ZnO structure and a preparation method. The light-emitting diode and laser includes a p-GaN layer, a ZnO-ZnMgO multi-quantum well layer, an n-ZnO layer and metal electrodes. The preparation method includes the steps of: first adopting a molecular beam epitaxy method to successively prepare the ZnO/ZnMgO multi-quantum well layer and the n-ZnO layer on a p-GaN film; and then plating the metal electrodes in p-GaN and n-ZnO regions respectively. The device prepared by the invention adopts the ZnO/ZnMgO multi-quantum well as an active layer, and a threshold value of the light-emitting diode and laser be lowered and luminous efficiency can be improved; in addition, to solve the problem that efficient and stable p-ZnO is difficult to realize in a homogeneous structure, the device adopts p-GaN as a hole injection layer; and at the same time, compared with other p type materials, GaN has the advantages of having the same structure as ZnO and having low epitaxial mismatch.

The invention discloses a preparation method of lead telluride quantum dots, which comprises the following steps: continuously introducing inert gas, adding lead telluride powder into a solvent, carrying out probe ultrasonic treatment for 6-12 hours at a water bath temperature of 10-15 DEG C, carrying out water bath ultrasonic treatment for 48-72 hours, centrifuging, and carrying out vacuum drying to obtain the lead telluride quantum dots. The preparation method is simple and efficient, the impurity amount of the prepared lead telluride quantum dots is small, the size distribution is uniform, and the invention further discloses the lead telluride quantum dots prepared through the preparation method of the lead telluride quantum dots. The lead telluride quantum dot is uniform in size, the characteristic absorption peak in an ultraviolet visible-near infrared spectrum is 450-550 nanometers, and the lead telluride quantum dot can be used as an active material in a photoelectrochemical photoelectric detector.