47results about How to "Strong red light emission" patented technology

The invention relates to the field of inorganic light emitting materials and discloses a red oxyfluoride phosphor for blue light semiconductor light emitting diodes and a preparation method of the red oxyfluoride phosphor. The chemical composition of the novel Mn<4+> excited red oxyfluoride phosphor for the blue light semiconductor light emitting diodes is A2Nb(1-x)OF5:xMn<4+>; A is Cs, Rb or Na; x represents a molar percentage coefficient of correspondingly doping Mn<4+> ions to Nb<5+> ions, and x is larger than 0 and smaller than or equal to 0.10. The related red phosphor mainly emits red light at about 632 nm under the blue light excitation and has high light emitting efficiency. The blue light excited high-color-purity red oxyfluoride light emitting material is performed in a solution. The preparation method adopts a simple synthesis process and is applicable to industrial mass production.

The invention relates to a preparation method of a red fluorescent powder for LED, which comprises the following steps: (1) dissolving a given amount of europium oxide in concentrated nitric acid; heating and stirring until the europium oxide is completely dissolved; continue heating for evaporation to dryness, and then adding deionized water to obtain a solution A; dissolving a given amount of sodium tungstate or ammonia tungstate in the deionized water to obtain a solution B; (2) dropwise adding the solution B to the solution A and continuously stirring to obtain a white turbid solution, and then adding a salpeter solution or a sodium hydroxide solution to the white turbid solution to regulate the pH value to 2-4; (3) filling the white turbid solution to a high pressure kettle, heating to 170-240 DEG C, preserving heat for 20-72 hours, and naturally cooling to the room temperature; and (4) filtering and drying obtained products to obtain the red fluorescent powder. The invention hassimple process, is easy to implement and can reduce the probability of introducing impurities; the preparation process of the preparation method requires simple equipment, has high reaction speed andis more suitable for large-scale production.

The invention provides a red-light enhanced up-conversion luminescent porous ZnO nanoparticle and a preparation method thereof. A red-light-enhanced upconversion luminescent porous ZnO nanoparticle is a ZnO nanoparticle doped with Yb, Er, and Mn, including the following raw materials made, Zn 2+ Ionic solution, Yb 3+ Ionic solution, Er 3+ Ionic solution, Mn 2+ Ionic solution, CO 3 2‑ Ionic solution, where Zn 2+ : Yb 3+ :Er 3+ :Mn 2+ The molar ratio of Zn is 2+ : Yb 3+ :Er 3+ :Mn 2+ =100~60: 3~6: 0.3~0.6: 6~10. The ZnO nanoparticles are prepared by thermal decomposition and high-temperature calcination. The shape of the ZnO nanoparticles is regular spherical, small in size, porous, and the red light emission is enhanced.

The invention discloses a method for preparing a round cake-shaped europium-doped lanthanum vanadate red fluorescent powder. The method selects PVP as a template agent, uses lanthanum nitrate or lanthanum chloride as the lanthanum source, and uses europium nitrate or europium chloride as the lanthanum source. Europium source, using sodium metavanadate or ammonium metavanadate as vanadium source, using hydrothermal reaction method, by changing initial pH, hydrothermal reaction time and temperature, europium source content and PVP content, round cakes with different diameters can be obtained. The europium-doped lanthanum vanadate red phosphor has a diameter of 1~5.5μm and a thickness of 0.1~0.5μm. It has a tetragonal zircon phase structure and good red light emission properties. The method of the invention has simple raw materials and easy operation, the prepared product has high purity and regular particles, and the product particle morphology and phase structure are controllable, and has strong red light emission, and the obtained round cake-shaped europium-doped lanthanum vanadate is obtained Crystals have excellent application prospects in the fields of PDP, LED, photocatalysis and luminescent ceramics.

The invention belongs to the technical field of rare earth luminescent materials, and in particular relates to fluorescent powder capable of being effectively excited by blue light and a preparation method thereof. The general formula of chemical compositions of the fluorescent powder is Li2Sr1-z(SiO4)1-0.75x-0.5y(M1O4)x(M2O4)y:zEu2+, wherein M1 refers to P; M2 refers to S; x is more than or equal to 0 and less than or equal to 0.2; y is more than or equal to 0 and less than or equal to 0.3; and z is more than or equal to 0 and less than or equal to 0.01. The preparation method comprises the following steps of: correctly weighing raw materials in a stoichiometric ratio of the general formula, uniformly mixing the raw materials fully, and pre-sintering the raw materials into a high temperate furnace at the temperature of between 400 and 800 DEG C for 1 to 12 hours; and sintering the pre-sintered raw materials in the reducing atmosphere at the temperature of between 700 and 1,000 DEG C for 1 to 10 hours. The fluorescent powder can be effectively excited by the blue light between 400 and 550nm, intense fluorescence-emission of which the main peak is about 580 to 610nm is obtained, and the fluorescent powder can be matched with a blue LED chip and is used for assembling white LEDs. Meanwhile, the fluorescent powder also can be excited by ultraviolet light between 250 and 280nm to emit intense red fluorescence. The fluorescent powder prepared by the invention has stable chemical properties, the preparation process is easily controlled, and the industrial production can be realized by utilizing basic equipment in the current fluorescent powder plants. Therefore, the fluorescent powder is new fluorescent powder with application potential.

The invention discloses a preparation method and application of a hydrogen peroxide ratio fluorescent molecular probe based on a DCPO core, and its chemical structural formula is as follows: The ratiometric detection of hydrogen oxide can greatly reduce the interference of other detection conditions and improve the detection accuracy. At the same time, the probe also has the advantages of good water solubility, high sensitivity and strong specificity, which can avoid the interference of other analytes. The probe has strong red light emission, can effectively avoid the interference of biological autofluorescence, has good cell membrane permeability and low cytotoxicity, and has strong practical application value in the fields of environment and life sciences.