Unlock instant, AI-driven research and patent intelligence for your innovation.

Fluorescent powder for LEDs (light-emitting diodes) and preparation method thereof

A technology of phosphor powder and fluxing agent is applied in the field of phosphor powder for white light LED and its preparation, which can solve the problems of decreased luminescence performance, high requirements for synthesis equipment, and small adjustable range of luminescence peak wavelength, and achieves simple preparation method and low cost. The effect of low cost and easy availability of raw materials

Active Publication Date: 2014-07-23
JIANGSU BREE OPTRONICS CO LTD
View PDF4 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Its synthesis method is mainly a high-temperature solid-phase method, which usually requires a high temperature above 1600°C, which requires high synthesis equipment. At the same time, the adjustable range of the luminous peak wavelength of YAG phosphor is relatively small (535nm-570nm), especially when the emission wavelength When it is larger than 560nm, the luminous performance drops significantly

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Fluorescent powder for LEDs (light-emitting diodes) and preparation method thereof
  • Fluorescent powder for LEDs (light-emitting diodes) and preparation method thereof
  • Fluorescent powder for LEDs (light-emitting diodes) and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Weigh 0.939mol La 2 o 3 , 1mol Al 2 o 3 , 0.12mol CeO 2 , 4mol SrCO 3 , 0.001mol Dy 2 o 3 and 1% NH by total weight of raw material 4 Cl is used as a flux and mixed evenly. The above mixture is placed in a reducing atmosphere furnace and baked at 1400°C for 8 hours. After cooling out of the furnace, the composition is sieved. The expression of the phosphor is La 0.939 Sr 2 AlO 5 : Ce 3+ 0.06 , Dy 3+ 0.001 .

Embodiment 2

[0027] Weigh 0.94mol La 2 o 3 , 0.9mol Al 2 o 3 , 0.1mol Ga 2 o 3 , 0.08mol CeO 2 , 4mol SrCO 3 , 0.01molNd 2 o 3 , 0.01molGd 2 o 3 and 1.5% SrCl of the total weight of raw material 2 1.5% AlF with the total weight of raw materials 3 As a flux and mixed evenly, the above mixture is placed in a reducing atmosphere furnace and baked at 1550°C for 2 hours. After cooling out of the furnace, the composition is sieved. The expression of the phosphor is La 0.94 Sr 2 Al 0.9 Ga 0.1 o 5 : Ce 3+ 0.04 ,Nd 3+ 0.01 ,Gd 3+ 0.01 .

Embodiment 3

[0029] Weigh 0.96mol La 2 o 3 , 0.7mol Al 2 o 3 , 0.3mol Ga 2 o 3 , 0.04mol CeO 2 , 4mol SrCO 3 , 0.005molNd 2 o 3 , 0.015molGd 2 o 3 and 0.4% SrCl of the total weight of raw material 2 1.6% AlF with total weight of raw material 3 As a flux and mixed evenly, the above mixture is placed in a reducing atmosphere furnace and baked at 1500°C for 4 hours. After cooling out of the furnace, the composition is sieved. The expression of the phosphor is La 0.96 Sr 2 Al 0.7 Ga 0.3 o 5 : Ce 3+ 0.02 ,Nd 3+ 0.005 ,Gd 3+ 0.015 .

[0030] The emission spectrogram and the excitation spectrogram of the fluorescent powder obtained in Examples 1-3 are shown in figure 1 and figure 2 ,From figure 1 and figure 2 It can be seen that adjusting the amount of Ga can change the optimal excitation peak and emission peak position of the phosphor.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
particle diameteraaaaaaaaaa
Login to View More

Abstract

The invention relates to fluorescent powder for LEDs (light-emitting diodes). The chemical structural formula of the fluorescent powder refers to La1-x-ySr2(Al1-zGaz)O5:Ce3+x, J3+y, wherein J is one out of or the combination in any proportion of more than two out of Dy, Nd, Ho, Gd, Sm, Y or Lu; x is more than or equal to 0.01 and less than or equal to 0.2; y is more than or equal to 0.001 and less than or equal to 0.02; and z is more than or equal to 0 and less than or equal to 0.3. A preparation method of the fluorescent powder comprises the steps of weighing oxides of La2O3, Al2O3, Ga2O3, CeO2, SrCO3 and J according to stoichiometric ratio in the chemical structural formula, adding fluxing agent into the oxides, uniformly mixing the fluxing agent and the oxides, then sintering the mixture in a reducing atmosphere furnace for 2-8 hours at a temperature of 1400-1550 DEG C, and finally cooling and screening the obtained product to obtain the fluorescent powder. The fluorescent powder can send out light in the scope of yellow green to orange red under the excitation of near ultraviolet or blue light, can be used by an LED emitting white light under the excitation of blue-light LED chips, and is good in luminescent property, high in phase purity, simple in preparation process and easy to operate.

Description

technical field [0001] The invention relates to a fluorescent powder for white light LEDs and a preparation method thereof, belonging to the technical field of solid luminescent materials. Background technique [0002] White light LED is based on the light mixing principle of colorimetry. The LED phosphor is combined with the GaN blue light chip. After absorbing the blue light emitted by the GaN chip, the phosphor emits long-wave green, yellow or red light. The transmitted blue light mixes to achieve white light emission. The current mainstream LED packaging form is to use a combination of blue light chips and yellow phosphors to obtain white light LEDs. This combination not only ensures the high luminous efficacy of LEDs but also ensures the long life of LEDs. As one of the key materials, the light conversion efficiency, spectral structure, bandwidth, powder particle size, and powder-glue compatibility of yellow phosphor powder for LED directly determine the lumen efficien...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C09K11/80
CPCY02B20/181Y02B20/00
Inventor 符义兵何锦华梁超滕晓明
Owner JIANGSU BREE OPTRONICS CO LTD