62 results about "White emission" patented technology

The present application belongs to the technical field of luminescent materials, and relates to a cerium metal-organic framework for white light emission and a preparation method and application thereof, to solve the problems that traditional white light LED needs to utilize multiple metal composites or multiple matrix composites and be sintered at high temperature to obtain multi-color fluorescent powder, and needs to be matched with corresponding LED chips to emit white light, and the corresponding preparation conditions are complex and the cost is high. 4,4'-(1H-pyrazole-1,3-diyl)dibenzoic acid is added into N,N-dimethylformamide; cerium salt is added into water; then the above two solutions are mixed and nitric acid is added, and hydrothermal reaction is carried out to obtain the cerium metal-organic framework material for white light emission. The preparation method disclosed by the present application is simple and has a high yield (>=82%). The prepared cerium metal-organic framework material can realize full-spectrum white light emission of a single matrix and a single metal ion, and the luminescent color coordinate value is close to the white light emission region (0.33, 0.33).

A lighting apparatus is disclosed. The lighting apparatus according to one embodiment of the present disclosure includes: a white light emitting device including at least one first light emitting diode and a wavelength converter to implement white light; and at least one second light emitting diode emitting light suitable for producing a cell activating substance, wherein the first light emitting diode emits light having a central wavelength in a range of about 300 nm to about 420 nm, the second light emitting diode emits light having a central wavelength in a range of about 605 nm to about 935 nm, the wavelength converter includes a plurality of wavelength conversion substances to convert light of the first light emitting diode into white light, the lighting apparatus emits the white light implemented in the white light emitting device and light generated by the second light emitting diode to the outside, and, in irradiance spectrum of the white light implemented in the white light emitting device, irradiance of the central wavelength of light emitted from the first light emitting diode is smaller than that of a peak wavelength of blue light emitted from the wavelength conversion substance.

The present invention discloses the preparation and application of a cheap metal-organic fluorescent material for high-power LED lighting. The chemical formula of the complex is: [Cu₄I₄(bbimb)₂]ₙ, where the ligand bbimb is 1,2-bis((1H-benzoimidazol-1-yl)methyl)benzene, and its chemical formula is: C₂₂H₁₈N₄; the complex crystal belongs to the monoclinic system, the space group of the complex is P21 / c, and the crystal parameters of the complex are a = 11.3850(3) Å, b = 16.1962(3) Å, c = 26.8795(6) Å, α = 90°, β = 98.879(2)°, γ = 90°, Z = 4, V = 4897.02(19) ų. The present invention also provides a preparation method of the complex, which is simple, has good stability and high yield. The obtained complex shows orange fluorescence emission under the irradiation of a 365 nm ultraviolet lamp. And a large temperature range of zero thermal quenching occurs in the temperature range from 80 K to 500 K, and its fluorescence intensity hardly quenches with the increase of temperature, having broad application prospects in the field of ZTQ materials. Moreover, the optical properties of the LED assembled with the complex as the material are studied, and the LED shows good white light emission performance under high-throughput current.

The present invention discloses a Eu 2+ -doped single-phase white light-emitting phosphor and a preparation method thereof. The Eu 2+ -doped single-phase white light-emitting phosphor of the present invention has a chemical general formula of Ca 9‑y LiMg 1‑x A 2x / 3 (PO4)7: yEu 2+ , wherein A is selected from Al and / or Ga; x and y respectively represent numerical values within the following ranges: 0.1 ≤ x < 1.0, 0.001 ≤ y ≤ 0.2. The Eu 2+ -doped single-phase white light-emitting phosphor of the present invention, by adding Al and / or Ga, causes local structural distortion, induces the redistribution of Eu 2+ , thereby broadening the full width at half maximum of the emission peak and the emission band, enabling its spectral range to cover the entire visible light region, having good continuity of the emission spectrum and a complete spectrum, and the peak shape of its emission peak being similar to the visible light peak shape of sunlight, improving the luminescence quality of the phosphor, making its emitted light close to the natural light level, and having a good LED white light illumination effect.

The invention belongs to the technical field of nano materials, and discloses a preparation method of an Au nano material with a layered hybrid superlattice structure. According to the method, a coordination confinement synthesis strategy is adopted, 4-mercaptobenzoic acid is taken as a structure-directing agent, and the organic-inorganic alternating layered superlattice structure is successfully prepared under the condition of CO weak reduction by utilizing a strong coordination bond formed by sulfydryl of 4-mercaptobenzoic acid and gold and a pi-pi conjugate synergistic effect of a benzene ring and combining a soft template confinement effect of octadecylamine. The superlattice material has a long-range disordered amorphous structure and an adjustable interlayer spacing (2.9 to 4.7 nm), and shows the white light emission characteristics of wide-spectrum ultraviolet-visible absorption (250 to 600 nm) and adjustable color temperature (3200 to 6500 K). According to the invention, a quantitative structure-function relationship of interlayer spacing-ligand metal interaction-optical performance is established, effective regulation and control of intersystem crossing process and phosphorescence lifetime from microsecond to millisecond magnitude are realized, and an innovative solution is provided for solving the problem of metal-organic layer interface compatibility; and an important material platform and theoretical support are provided for developing a novel flexible photoelectric device.

The invention relates to fluorescent powder based on ultraviolet excitation near-white light, in particular to Sm < 3 + > doped Sr9La (VO4) 7, the chemical formula is Sr9La (1-x) Smx (VO4) 7, x is larger than 0 and smaller than or equal to 0.25, the fluorescent powder can achieve near-white light emission under ultraviolet excitation, the emission color is adjustable along with the temperature, visual non-contact temperature measurement can be achieved through color change within the range of 298-573 K, and sensitivity is high. A high-temperature solid-phase method is adopted for preparation, the process is simple, raw materials are easy to obtain, and the purity requirement is easy to meet.

The application relates to the technical field of inorganic photoluminescence materials, and discloses a rare earth doped layered stannate-based white light fluorescent powder material and a preparation method thereof, a chemical molecular formula of which is A1-xSn2-xO6:Eu3+, wherein 0 < x <= 0.05, A is one or more divalent alkali earth metal ions in Ca, Sr and Ba, and is doped in different proportions, the A provides a red light emission component, the A provides a blue and yellow light emission component, the emission intensity of the red light and the blue and yellow light can be adjusted by regulating and the doping proportion, the ionic radius of the A is similar to that of the A, and the A substitutes the lattice position. Through the synergic doping of the A and the A and the proportion regulation, the charge compensation and the lattice position optimization of the A and the A are combined, the accurate matching of the red light and the blue and yellow light emission intensity of the fluorescent powder is realized, white light emission effects with excellent color rendering and stable color tone are obtained, and the problems of red light loss or light emission efficiency decay caused by the mixing of multi-color fluorescent powder in traditional white light LED fluorescent powder are effectively overcome.

The present invention belongs to the technical field of luminescent materials, and specifically discloses a thermochromic luminescent material and a preparation method thereof. The material with thermochromic luminescent properties has a chemical formula of (C 11 H 26 N)2Cu2I4. It has obvious thermochromic luminescent characteristics. At room temperature, it exhibits blue light emission under the excitation of 365 nm ultraviolet light, while when the temperature rises to 100 °C, it will exhibit warm white light emission under the excitation of 365 nm ultraviolet light, and can be especially used as a thermochromic luminescent material. Moreover, the preparation process of this material is simple, low in cost, and good in repeatability.

The invention relates to the technical field of fluorescent powder materials, in particular to a lead-free double-perovskite fluorescent powder material and a preparation method and application thereof, the chemical formula of the lead-free double-perovskite fluorescent powder material is Cs2ZrCl6: 1% of Te < 4 + > and 3% of Mo < 4 + >, and 1% of Te < 4 + > and 3% of Mo < 4 + > are doping proportions; the lead-free double-perovskite fluorescent powder material prepared by the invention can be applied to preparation of white light-near infrared LED devices and composite X-ray scintillator films; the lead-free double perovskite fluorescent powder material prepared by the invention can simultaneously realize high-efficiency white light emission, near-infrared emission and X-ray excited radiation luminescence, so that the spatial consistency and acquisition synchronism of multispectral images are ensured from a hardware source, and the problems of image pixel dislocation, resolution mismatch, high resolution ratio and the like caused by the use of various luminescent materials at present are solved. And the later image fusion processing flow is complex and time-consuming.

A light-emitting diode (LED) array comprises: a plurality of pixels, each of the pixels comprising respective groups of light emitting diodes (LEDs), the plurality of pixels comprising: a first set of pixels configured to emit a first red dominant wavelength; a second set of pixels configured to emit a first green dominant wavelength; a third set of pixels configured to emit a first blue dominant wavelength; the first red dominant wavelength, the first green dominant wavelength, and the first blue dominant wavelength defining a RGB (red-green-blue) gamut; and a fourth set of pixels configured to emit a non-white emission comprising a luminous efficacy that is higher than either of the first set of pixels or the third set of pixels to increase power efficiency of the device.

The invention discloses cold and warm white light adjustable perovskite fluorescent powder prepared by an ultrasonic-assisted hydrochloric acid method. The chemical general formula of the perovskite fluorescent powder is Cs2ZrCl6: xBiamp, 0 < = x < = 0.2, and 0 < = y < = 0.99. The purpose of the invention is to realize temperature-adjustable white light emission of lead-free rare earth-free perovskite under the excitation of ultraviolet light with different wavelengths. The preparation scheme comprises the following steps: 1, dissolving zirconium source powder, bismuth source powder and tellurium source powder in hydrochloric acid according to a certain proportion, and stirring to obtain a clear solution; 2, adding a certain proportion of cesium source powder into the clear solution; and 3, carrying out ultrasonic treatment, centrifugal washing and vacuum drying on the solution to obtain the lead-free and rare earth-free Cs2ZrCl6: xBiamp with adjustable cold and warm white light, the invention relates to yTe perovskite fluorescent powder. The preparation method comprises the following steps: preparing Cs2ZrCl6: xBiamp by using an ultrasonic-assisted hydrochloric acid method; the yTe perovskite fluorescent powder can realize emission from cold white light to warm white light by changing the excitation wavelength of ultraviolet light. The method disclosed by the invention is simple in preparation, short in time consumption, low in cost, green and environment-friendly; the yTe white-light fluorescent powder has a good application prospect in the field of solid-state illumination.

The invention provides Eu < 3 + >-doped single-matrix white light emitting fluorescent powder as well as a preparation method and application thereof, and belongs to the technical field of luminescent materials. The preparation method comprises the following steps: providing an initial luminescent material R4.667Si3O13: xEu < 3 + >, where R is Y < 3 + >, Lu < 3 + >, Gd < 3 + > or La < 3 + >, and the mole number x of Eu < 3 + > replacing R satisfies 0.005 < = x < = 0.10; the initial luminescent material is subjected to at least three stages of heating annealing treatment in a reducing atmosphere, and the Eu < 3 + > doped single-matrix white light emitting fluorescent powder is obtained. According to the invention, an R4.667Si3O13: xEu < 3 + > initial red luminescent material is used as a matrix, through a specific post-annealing process, stable oxygen vacancy is introduced into crystal lattices, an Eu < 3 + > coordination environment is reconstructed, multi-energy-level luminescence transition of 5D0, 5D1, 5D2 and 5D3 energy levels is activated, and finally white light emission in a single matrix is realized.

The invention discloses a preposed light performance enhanced composite fluorescent ceramic for laser illumination and a preparation method thereof. The composite fluorescent ceramic comprises YAG: Ce fluorescent ceramic and ZrO2-Al2O3 ceramic, wherein a zigzag microstructure is constructed on the surface of the YAG: Ce fluorescent ceramic, and the ZrO2-Al2O3 ceramic and the YAG: Ce fluorescent ceramic are sintered into a whole. According to the zigzag microstructure YAG: Ce ceramic, the contact interface area with blue light can be increased, so that the probability of interaction between the blue light and the ceramic is improved, and the fluorescence conversion efficiency is improved; meanwhile, the sawtooth-shaped microstructure can reduce the total internal reflection effect of fluorescent light, and can regulate and control the propagation direction of emergent light, so that blue light and yellow light can be mixed more uniformly. The composite fluorescent ceramic prepared by the invention realizes high-brightness white light emission under the excitation of a blue light LD chip with the wavelength of 450-460 nm, and can bear the excitation power density of 60-75 W / mm < 2 > and the luminous efficiency of 210-260 lm / W. Compared with the traditional planar fluorescent ceramic without a microstructure, the luminous efficiency is improved by 40-60%, the divergence angle of emergent light is reduced from more than 100 degrees of a planar structure to 60-80 degrees, and the thermal conductivity at 20-30 DEG C is 20-27Wm <-1 > k <-1 >.

The application provides a white light phosphor powder based on copper-iodine organic hybrid clusters and a preparation method thereof, and has a structure shown in formula I. The structure of the white light phosphor powder in the application is that Cu4I4 is used as an inorganic core, and copper atoms are coordinated with nitrogen and phosphorus atoms on ligands to form a stable and unique cluster structure. The light emitting mechanism of the cluster is charge transfer from the inorganic core to the ligand, and the simple core and the ligand cooperate with each other to form degenerate emission energy levels, so that white light emission with double wide peaks from 400 to 800 nm is realized. The light emitting quantum yield reaches 97.8%. The material also exhibits excellent stability, and the thermal decomposition temperature is as high as 265 DEG C. The material also has low thermal quenching, and still maintains more than 80% of the original light emitting quantum yield under the condition of 240 DEG C. The application also provides an application of the white light phosphor powder based on copper-iodine organic hybrid clusters. The white light phosphor powder is applied to the field of solid state lighting, and has significant advantages and application prospects.

The application provides a white fluorescent powder and a preparation method and application thereof, and belongs to the technical field of fluorescent powder, wherein the chemical formula of the fluorescent powder is Sr 1‑x Ca x Gd 1‑y‑z AlO4:yDy 3+ / zTm 3+ , wherein x, y and z are molar numbers, x is 0.015-0.025, y is 0.01-0.03, and z is 0.005-0.02. The application adopts Ca 2+ and Tm 3+ to dope SrGdAlO4:Dy 3+ fluorescent powder, so as to improve the luminescent performance of SrGdAlO4:Dy 3+ fluorescent powder, and achieve the purpose of high-efficiency white light emission; under the same excitation wavelength, SrCaGdAlO4:Dy 3+ / Tm 3+ fluorescent powder can simultaneously show the characteristic emission peaks of Dy 3+ and Tm 3+ . After Tm 3+ doping, the blue light emission intensity can be improved, and by changing the relative doping concentration ratio of Dy 3+ and Tm 3+ , the SrCaGdAlO4:Dy 3+ / Tm 3+ fluorescent powder can be modulated from warm white light to cold white light.

The invention belongs to the field of bearing state monitoring, and particularly relates to a bearing vibration detection system based on a white light LED. The bearing vibration detection system comprises a vibration sensor used for collecting vibration signals generated by a bearing, and a signal conditioning circuit used for processing the vibration signals collected by the vibration sensor into digital signals. The white light LED transmitting module is used for outputting the vibration signal in the digital signal form obtained by the signal conditioning circuit through a white light LED signal; the white light LED receiving module is used for receiving a white light LED signal transmitted by the white light LED transmitting module; and an electric signal obtained by the white light LED receiving module is used for extracting vibration information of the bearing. Due to the fact that the white light LED signals do not affect operation of the bearing, the white light LED signals are basically not limited under the interference working conditions of high temperature, high voltage, strong electromagnetic interference and the like where the bearing is frequently located, the influence on transmitted bearing vibration information is small, the situation that the vibration information cannot be transmitted rarely occurs, and the effect of strong anti-interference performance is achieved.

The invention discloses a visible-near infrared luminous rare earth doped lead-free double perovskite material which is synthesized by introducing processes of heating and stirring, ultrasonic mixing, gradient cooling and the like on the basis of a traditional hydrothermal method to synthesize a Sb < 3 + > / Er < 3 + > co-doped Cs2Na0. 95Ag0. 05YbCl6 double perovskite material. By effectively reducing the defect density in a crystal structure, the obtained material has the multi-wavelength luminescence characteristic from visible light to near-infrared light, single-component white light emission and near-infrared luminescence can be realized, and meanwhile, accurate temperature sensing can be carried out in a fluorescence intensity ratio (FIR) mode by utilizing the temperature dependence difference of rare earth ions Sb < 3 + > and Er < 3 + >. Therefore, the material can be applied to the aspects of high-precision optical temperature sensing detection, single-component white light LED illumination, near-infrared imaging and the like, and has wide application prospects and important social and economic values.

This invention discloses a trapezoidal composite fluorescent glass-ceramic for laser illumination and its preparation method. The composite fluorescent glass-ceramic comprises a trapezoidal fluorescent glass and a high thermal conductivity ceramic coating on the outer layer of the fluorescent glass. The trapezoidal fluorescent glass is formed by melting and casting waste glass doped with luminescent ceramic powder, red phosphor, and high thermal conductivity powder. The composite glass-ceramic prepared by this invention achieves high-brightness white light emission under excitation by a 460nm blue LD chip, with a color rendering index of 82-91, and can withstand an excitation power density of 40W / mm². 2 ~55W / mm 2 Its luminous efficacy is 206–265 lm / W, and its thermal conductivity at room temperature is 18–29 Wm. ‑1 k ‑1 .

Disclosed is optical observation equipment for identifying the forming process of a malignant tumor, which is provided with a receiving space and a transparent front end. The optical observation equipment comprises: a light-guide fiber, a laser emitter, a focusing device, a white light emitter, an image sensor, a high gain amplifier and an encoding and emitting device, wherein the light-guide fiber extends to the transparent front end from the receiving space; the laser emitter emits laser with a wavelength of 340 nm±20 nm and an energy of 0.3˜0.5 mj / m2 in a pulsing mode; the focusing device is coupled to the output end of the laser emitter and used for focusing the laser to the input end of the light-guide fiber; the white light emitter is used for emitting white light, and the white light is guided into the input end of the light-guide fiber, wherein the laser emitter and the white light emitter are alternately turned on; the image sensor is used for acquiring an image of an area irradiated by light emitted from the output end of the light-guide fiber and converting a light signal into an electric signal; the high gain amplifier is coupled to the image sensor and is used for amplifying the electric signal generated by the image sensor; and the encoding and emitting device is coupled to the high gain amplifier and is used for encoding the signal output by the high gain amplifier and emitting the encoded signal.

The invention discloses an efficient single-phase full-spectrum luminescent metal halide luminescent material and a preparation method thereof. The chemical composition of the luminescent material is Cs2ZrCl6: Bi < 3 + > and Te < 4 + >. The method comprises the following steps: (1) weighing a proper amount of CsCl, ZrO2, BiCl3 and TeCl4 by using an electronic balance according to the stoichiometric ratio of materials, and putting the CsCl, ZrO2, BiCl3 and TeCl4 into a lining of a polytetrafluoroethylene reaction kettle; 2) adding a certain amount of concentrated HCl into the lining of the reaction kettle, and stirring for a certain time to dissolve all the raw materials; 3) taking out the stirrer, sealing the reaction kettle, placing the reaction kettle in an air dry oven, and reacting for a certain time at a certain temperature; and 4) washing the reaction product, and carrying out vacuum drying to obtain the Cs2ZrCl6: Bi < 3 + >, Te < 4 + > material. The material emits bright white light under the excitation of ultraviolet light. The synthesis method disclosed by the invention has the characteristics of low raw material cost, simple experimental operation, batch synthesis and the like; meanwhile, the obtained product is good in crystallinity, high in stability, environment-friendly and excellent in luminescent property; the method can be used in the technical fields of illumination display, anti-counterfeiting, photoelectric detection and the like.

The invention relates to a white organic light-emitting device of a diboron azaanthracene derivative and a preparation method of the white organic light-emitting device. The diboron azaanthracene derivative, namely BNAnti-OMe, is a diboron nitrogen doped anthracene micromolecular material, and the material has the characteristics of relatively wide band gap, relatively strong blue fluorescence emission, relatively high triplet state energy level and the like. Double light-emitting layers of the organic light-emitting device comprise an intrinsic blue fluorescent light-emitting layer of BNAL-OMe, a red phosphorescent light-emitting layer of BNAL-OMe gradient doped Ir (MDQ) 2acac, a transparent conductive ITO glass substrate, a hole injection layer HATCN and a hole transport layer TAPC, wherein the transparent conductive ITO glass substrate, the hole injection layer HATCN and the hole transport layer TAPC are located on the left side of the intrinsic blue fluorescent light-emitting layer of BNAL-OMe in sequence. And an n-type doped hole barrier layer BCP: TmPyPb, an electron transport layer TmPyPb, an electron buffer layer LiF and a metal back electrode Al are sequentially arranged on the right side of the BNAL-OMe: Ir (MDQ) 2acac light-emitting layer. According to the double-boron azaanthracene derivative light-emitting layer and the double-boron azaanthracene derivative gradient doped red phosphorescent dye light-emitting layer, white light emission is achieved through light color complementation, and the color stability and the brightness of a white light device can be effectively improved through the fluorescent / phosphorescent double-light-emitting-layer design of the double-boron azaanthracene derivative light-emitting layer and the double-boron azaanthracene derivative gradient doped red phosphorescent dye light-emitting layer.

The invention discloses an organic light-emitting material, an organic light-emitting diode device, a preparation method and application, and relates to the technical field of light-emitting diodes. The organic light-emitting diode device comprises an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer and a cathode which are arranged in sequence; wherein the light-emitting layer comprises an oxazole hybrid local charge transfer state (HLCT) light-emitting material as an exciton sensitizer, and the exciton sensitizer has local excited state and charge transfer state characteristics, has high exciton utilization efficiency and excellent energy transfer capability, and can effectively improve the light-emitting efficiency and chroma stability of the device. And efficient excitation of the multicolor fluorescent dye is realized through an energy sensitization strategy, so that white light emission with excellent performance is obtained. The organic light-emitting diode device is simple in structure, high in light-emitting efficiency, stable in color and suitable for high-performance white light display and illumination application.

The invention relates to the technical field of fluorescent material preparation, in particular to fluorescent powder based on a negative thermal expansion material and a preparation method and application thereof. The fluorescent powder comprises an Sc2Mo3O12 matrix and Tm < 3 + > / Dy < 3 + > doped ions, and is prepared by a high-temperature solid-phase method. The fluorescent powder can obtain white light emission of color-adjustable coordinates by adjusting the concentration of Tm < 3 + > / Dy < 3 + > under excitation of the wavelength of 354 nm. When the concentration of Dy < 3 + > is 4%, the chromaticity coordinate of the fluorescent powder is (0.3311, 0.2877) close to ideal white light, the fluorescent powder shows good light-emitting stability in a wide temperature range of 298K to 573K, the light-emitting intensity at the high temperature of 573K can still keep 60% of the initial intensity at the room temperature, and the fluorescent powder can be widely applied to high-power and high-temperature environment white light LED illumination in the fields of precise instruments, aerospace and the like.

The present invention provides: a wavelength conversion sintered body which is capable of improving the luminous efficiency of white light and is capable of reducing the chromaticity difference with respect to radiation angle; and a white light emitting element. A wavelength conversion sintered body (10) comprises a phosphor material (11) represented by general formula Y3-x-yBaxAl5-xSixO12:Cey (wherein x + y < 3, 0 < x < 3, and 0 < y < 3), and fine particles (12) dispersed in the phosphor material (11). The fine particles (12) are composite oxides of Ba, Si, and Al.

The invention discloses an ionic coumarin-based rare earth complex as well as a preparation method and application thereof, and belongs to the field of organic photoelectric functional materials. 3-acetyl-4-hydroxycoumarin and a methoxy substituted derivative 4-hydroxy-6-methoxy-3-acetocoumarin thereof are used as organic antenna chromophores; triethylamine is used as a counter cation to prepare a series of ionic high-luminescence rare earth complexes; wherein the Tb < 3 + > complex 2 shows the highest luminous efficiency value of the coumarin-based rare earth complex due to the proper triplet excited state energy level of a Coum ligand and the low symmetric D2d triangular dodecahedron spatial configuration of the Coum ligand; the edge of an excitation band of the OMe series complex 6-9 is widened to a visible region, and the obviously widened excitation window is combined with the ionic charge characteristics of the OMe series complex 6-9, so that the complex becomes a potential candidate for visible light activation application which is safer and deeper in penetration; the Dy < 3 + > complex 9 shows double emission characteristics of OMe-Coum blue fluorescence and Dy < 3 + > characteristic yellow phosphorescence, and high-quality single-component composite white light emission is realized by fusing the OMe-Coum blue fluorescence and the Dy < 3 + > characteristic yellow phosphorescence.

The present invention discloses a high thermal conductivity and high color rendering index composite fluorescent ceramic for laser lighting and a preparation method thereof, wherein the composite fluorescent ceramic comprises (Gd, Ce)3(Al, Ga)5O as a main phase. 12 phase, and the second phase Al2O3 uniformly distributed in the main phase, in which the luminescent ion is Ce 3+ ; Using GdGaO3, CeO2, and Al2O3 as the initial raw materials, the solid phase reaction method is adopted for sintering. The excitation spectrum of the composite ceramic prepared by the present invention is excited at a wavelength of 460nm, the main peak of the emission spectrum is between 567 and 582nm, and the half-maximum width is between 105 and 120nm. Under the excitation of a blue light LD (1 to 5W) with a wavelength of 455nm, warm white light emission is achieved, the color temperature is 3800 to 4250K, and the color rendering index is between 78 and 84; the thermal conductivity is 20 to 25Wm ‑1 k ‑1 Compared with single-phase fluorescent ceramics, the thermal conductivity is increased by 40-69%, and the preparation method is simple, green and environmentally friendly, and can be used for the industrial production of LD devices.

A class of metal halide-based metal-organic frameworks (MOFs) materials with multicolor tunable long-lasting emission and white light properties were synthesized by self-assembly of 15-crown ether-5 (CE) ligands and metal halide salts (CdX2), resulting in three complexes (15-5-CdCl2, 15-5-CdBr2, and 15-5-CdI2). In the solid state, the complexes (15-5-CdCl2, 15-5-CdBr2, and 15-5-CdI2) all exhibited near-standard white light emission under 340 nm ultraviolet radiation at room temperature, with CIE coordinates of (0.28, 0.32), (0.31, 0.39), and (0.30, 0.34), respectively. Simultaneously, they exhibit excitation-dependent room-temperature phosphorescence (RTP) ranging from blue / cyan to green / yellow, with 15-5-CdCl2 and 15-5-CdBr2 exhibiting multicolor tunable and visible light luminescence (LPL) with time-resolved luminescence lifetimes as high as 1-2 seconds. Single-crystal X-ray diffraction analysis and theoretical calculations indicate that the bright LPL of 15-5-CdCl2 and 15-5-CdBr2 originates from the aggregation state induced by the 15-crown ether-5 ligand and halogen bonds. The LPL obtained in this way can be widely used in lighting and display devices, optical recording devices, biological imaging, security systems, and other fields.

An exemplary white light emitting device may include first and second LEDs operable to generate excitation light having a dominant wavelength in a range from 440 nm to 480 nm, where the first LEDs and second LEDs are mounted on a substrate; a first photoluminescence material which emits light having a peak emission wavelength in a range from 500 nm to 590 nm in response to the excitation light; and a second photoluminescence material which emits light having a peak emission wavelength in a range from 600 nm to 650 nm in response to the excitation light; wherein the first LEDs are covered by the first photoluminescence material, and the second LEDs are covered by the first and second photoluminescence materials.

The invention relates to a thermally activated delayed fluorescence (TADF) polymer material and a preparation method thereof.The preparation method comprises the steps that firstly, a non-conjugated polymer main chain PDFC-N3 is synthesized through a Suzuki condensation polymerization reaction and azidation treatment of a 3, 6-dibromo carbazole monomer (3, 6-CzBr) and bis-ether fluorene (DF-BO) with a flexible hexyl chain, and then the polymer main chain PDFC-N3 is synthesized through an azide reaction; then, a TADF red light unit TB and a TADF blue light unit DT in different proportions are hooked to the main chain through azide-alkynyl click reaction to realize post-functionalization, and the polymer is in double-peak emission. The polymer disclosed by the invention is relatively high in molecular weight, excellent in solution processability and relatively good in thermal stability, and when the molar ratio of a blue light unit to a red light unit hooked on a main chain of the polymer is 97: 3-90: 10, the polymer serving as a luminescent layer material realizes white light emission in a prepared non-doped organic electroluminescent device.

The invention discloses a white light LED light source, and relates to the technical field of light emitting diodes. According to the white light LED light source, the green light chip, the yellow light chip and the red light chip are adopted as excitation sources to excite the blue-green fluorescent powder, the orange red fluorescent powder and the dark red fluorescent powder respectively, the three-color excitation sources can accurately fill the lacked cyan and dark red spectrum gaps of a traditional white light LED, the full spectrum range of visible light of 450-680 nm can be evenly covered, and the light emitting efficiency is improved. The white light emission with high color rendering performance is realized; the blue light hazard level of the white light LED light source can reach the current highest safety rating, namely RG0 level, for blue light hazard of the light source, potential harm of blue light to eyes can be effectively reduced, eyesight health is protected, and circadian rhythm disorder is reduced.