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Method for improving luminescent intensity and stability of synthesized YAG (yttrium aluminum garnet):Ce fluorescent powder

A technology of luminous intensity and stability, applied in the field of rare earth luminescent materials, can solve the problems of severe color coordinate drift, low LED luminous efficiency, poor dispersion, etc., to achieve improved luminous intensity and stability, good luminous effect, dispersion and stability good sex effect

Inactive Publication Date: 2014-03-26
YIZHENG SENTAI CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although a lot of research has been carried out, there is still a big gap in the quality of YAG:Ce powder produced in my country, mainly reflected in the low luminous efficiency of LEDs after sealing and turning, but the light decay is very large, and the color coordinate drift after 1000 hours is also very serious.
In addition, the packaged products often have problems such as aperture and light spots
The main reason is that the YAG:Ce powder produced in my country has many shortcomings such as low brightness, poor stability and poor dispersion.

Method used

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  • Method for improving luminescent intensity and stability of synthesized YAG (yttrium aluminum garnet):Ce fluorescent powder
  • Method for improving luminescent intensity and stability of synthesized YAG (yttrium aluminum garnet):Ce fluorescent powder
  • Method for improving luminescent intensity and stability of synthesized YAG (yttrium aluminum garnet):Ce fluorescent powder

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Weigh Y according to the molar ratio Y:Al:Ce=2.94:5:0.06 2 o 3 , Al(OH) 3 , CeO 2 ,, the above are all analytically pure, add an appropriate amount of NaF flux, mix the above raw materials evenly, transfer them to an alumina crucible for compaction and place them in a high-temperature reaction furnace for high-temperature calcination, and introduce reducing gas at a temperature of 1600 ° C. Time 6h. After cooling to room temperature, take out the sample and grind it, and dry-sieve it through a 100-mesh sieve. For the XRD characterization of the sample, see figure 1 Sample A. Wash the obtained powder with hot water, then pass through a 200-mesh wet sieve, and put the sample obtained by the wet sieve into an oven at 100°C to dry to obtain a water-washed fluorescent raw powder for future use.

Embodiment 2

[0029] Take the washed fluorescent raw powder obtained in Example 1, put it in a tube furnace for secondary reduction with hydrogen-nitrogen mixed gas (5%-95%), the temperature is 1450°C, the holding time is 4h, and take it out after cooling to room temperature The sample is ground, and the fluorescence emission spectrum of the obtained sample is shown in figure 2 Sample 1, the XRD characterization of the sample is shown in figure 1 For sample B, its fluorescence intensity is 1.03 times that of the factory YAG product.

Embodiment 3

[0031] Take the washed fluorescent raw powder obtained in Example 1, add 8‰NH4HF2 and place it in a tube furnace for secondary reduction with hydrogen-nitrogen mixed gas (5%-95%), the temperature is 1450°C, the holding time is 4h, cool After reaching room temperature, the sample was taken out for grinding, and the fluorescence emission spectrum of the obtained sample was shown in figure 2 Sample 2, its fluorescence intensity is 1.02 times that of factory YAG products.

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Abstract

The invention belongs to the technical field of rare earth luminescent materials, and mainly relates to a method for obviously improving the luminescent intensity and stability of synthesized YAG (yttrium aluminum garnet):Ce fluorescent powder. The main process comprises the following steps: mixing raw materials according to composition requirements, and calcining at 1400-1700 DEG C to obtain YAG:Ce raw fluorescent powder; performing ball milling dispersion on the YAG:Ce raw fluorescent powder in an acidic water medium, filtering, and drying to obtain surface-acidic raw fluorescent powder; adding cosolvent, uniformly mixing, and performing reducing calcination in hydrogen gas and hydrogen-nitrogen mixed gas at 1400-1600 DEG C for 2-50 hours; and performing furnace cooling to room temperature under the protection of a reducing atmosphere, washing with water, performing grinding dispersion, filtering, washing, and drying to obtain the fluorescent powder. The acid treatment on the surface of the YAG:Ce fluorescent powder can guarantee the cerium reducing effect in the subsequent high-temperature calcination process and improve the dispersity of the YAG fluorescent powder. Thus, the YAG:Ce powder produced by the invention has the characteristics of high luminescent intensity, less luminance decrease, favorable dispersity and stability and the like. The YAG:Ce powder is suitable for synthesis of new fluorescent powder, and can be also used for reforming and upgrading waste fluorescent powder.

Description

technical field [0001] The invention belongs to the technical field of rare earth luminescent materials, and in particular relates to a simple method for improving the brightness and stability of synthetic YAG:Ce fluorescent powder. Background technique [0002] In recent years, white LED lighting has been called a new generation of green and environmentally friendly lighting sources after incandescent lamps and energy-saving lamps because of its characteristics of "energy saving", "environmental protection", "high efficiency" and "long life". With the improvement of LED chip and packaging technology and the transformation of the main application market of LED from decorative display to general lighting, there is a great tendency to replace traditional lighting. [0003] Since the production technology of blue LED chips is relatively mature, the mass production scheme of white LEDs is still a classic method of combining LED chips with fluorescent conversion materials. The m...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K11/80
Inventor 李永绣欧阳春梅饶阳周雪珍莫志健
Owner YIZHENG SENTAI CHEM
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