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Red fluorescent powder for white light LED based on blue light excitation and preparation thereof

A red phosphor, blue light excitation technology, applied in chemical instruments and methods, the use of gas discharge lamps, luminescent materials, etc., can solve the problem of poor chemical stability of sulfide phosphors and easy decomposition, production equipment requirements are too harsh, unable to manufacture problems such as production equipment, to achieve the effect of large application value, easy operation and low cost

Active Publication Date: 2009-07-22
JIANGSU BREE OPTRONICS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Sulfide phosphors have poor chemical stability and are easy to decompose, especially the precipitation of sulfur will easily cause corrosion to the chip, which will lead to the failure of the entire white LED device
Rare earth activated nitride red phosphor with Eu 2+ In order to activate ions, because the crystal field formed by the nitride material is strong, it emits red light, and has high luminous efficiency and chemical stability, but it needs to be synthesized under high temperature and high pressure (1600 ° C, above 10 atmospheres). matrix, the requirements for production equipment are too harsh, and domestic kiln manufacturers are still unable to manufacture such production equipment

Method used

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  • Red fluorescent powder for white light LED based on blue light excitation and preparation thereof
  • Red fluorescent powder for white light LED based on blue light excitation and preparation thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] 1. Weigh 43.85g SrCO 3 , 10.2g Al 2 o 3 , 0.53g Eu 2 o 3 and 0.31g H 3 BO 3 , where Eu 2 o 3 The purity of the product is 99.99%, and the others are analytically pure.

[0039] 2. Put the above raw materials in an oven at 80°C to dry the water, and mix the dried powder raw materials evenly.

[0040] 3. Put the mixture into a crucible and put it into a reducing atmosphere furnace, fill it with H 2 gas to ensure that the Eu 3+ Revert to Eu 2+ , sintered at 1300°C for 8 hours.

[0041] 4. Wash the powder block obtained in step 3 with 0.2 mol / L post-treatment liquid after crushing, and then wash with deionized water until neutral. The aforementioned post-treatment solution is prepared by the following materials in molar ratio: 5% hydrochloric acid: 90% nitric acid: 5% hydrofluoric acid

[0042] 5. Use a centrifuge to separate the powder slurry obtained in step 4, then dry the powder and pass it through a 200-mesh sieve to obtain about 41g of red fluorescent pow...

Embodiment 2

[0044] 1. Weigh 28.62g CaCO 3 , 0.98g La 2 o 3 , 18.74g Ga 2 o 3 , 0.88g Eu 2 o 3 and 0.37g NH 4 F, where Eu 2 o 3 The purity of the product is 99.99%, and the others are analytically pure.

[0045] 2. Add the above raw materials into a 500ml deionized beaker and stir, then place in an oven at 80°C to dry the water, and mix the dried powder raw materials evenly.

[0046] 3. The mixture was filled into a crucible which was then placed into a larger crucible filled with activated carbon pellets and covered. Then put it into a high temperature furnace and sinter at 1425°C for 6 hours.

[0047]4. Wash the powder block obtained in step 3 with 0.5 mol / L post-treatment liquid after crushing, and then wash with deionized water until neutral. The aforementioned post-treatment liquid is prepared by the following substances in molar ratio: 5% hydrochloric acid: 85% nitric acid: 10% hydrofluoric acid.

[0048] 5. The powder slurry obtained in step 4 is separated from water and...

Embodiment 3

[0050] 1. Weigh 53.68g BaCO 3 , 2.04g Pr 6 o 11 , 10.09g Al 2 o 3 , 0.19g Ga 2 o 3 , 1.76g Eu 2 o 3 and 0.54g Na 2 CO 3 , where Eu 2 o 3 The purity of the product is 99.99%, and the others are analytically pure.

[0051] 2. Add the above raw materials into a beaker containing a mixed solution of 400ml deionized water and 100ml ethanol and stir, then place the ethanol and water in an oven at 80°C to dry, and mix the dried powder raw materials evenly.

[0052] 3. Put the mixture into a crucible and put it into a reducing atmosphere furnace, filled with 95% N 2 +5%H 2 The mixed gas was sintered at 1375°C for 4 hours.

[0053] 4. After crushing the powder block obtained in step 3, wash with 1 mol / L post-treatment solution, and then wash with deionized water until neutral. The aforementioned post-treatment solution is prepared by the following substances in molar ratio: 10% hydrochloric acid: 85% nitric acid: 5% hydrofluoric acid.

[0054] 5. the powder slurry obtai...

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Abstract

The invention relates to blue light excitation based red phosphor powder for white light LED and a preparation method thereof. The chemical expression of the phosphor powder is as follows: (R3-x-1.5yRy)(R)2O6:Eux, in which R is at least one of Sr, Ca, Ba and Mg; R is either one of La, Pr, Nd, Gd, Dy, Er, Ho and Lu; R is at least one of Al and Ga; x is from 0.005 to 0.25; and y is from 0 to 0.2. The preparation method is that: raw materials containing R, R, R and Eu are mixed evenly with a fusing agent, put in a reducing atmospheres furnace for sintering, and then carried out final treatment to obtain the product. The red phosphor powder can be effectively excitated by the blue light, and has good thermal and photo stability, high red luminous intensity and ideal color purity.

Description

technical field [0001] The invention belongs to the technical field of rare earth luminescent materials, and in particular relates to a preparation method of red fluorescent powder for white LEDs activated by bivalent europium that can be effectively excited by blue light. Background technique [0002] A light emitting diode (light emitting diode, abbreviated as LED) is a semiconductor light emitting device that converts electrical energy into light energy. White light LED has many advantages such as high luminous efficiency, energy saving (80% less than incandescent lamps with the same luminous efficiency), long life (10,000 hours), earthquake resistance, environmental protection, etc., and is regarded as the "fourth generation lighting source" and replaces the current mainstream. Incandescent and fluorescent bulbs. [0003] Using blue chips to coat phosphor powder is the mainstream of white LED manufacturing. It has high luminous efficiency, relatively low cost, and simpl...

Claims

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Application Information

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IPC IPC(8): C09K11/80H01L33/00
CPCY02B20/181Y02B20/00
Inventor 符义兵何锦华梁超
Owner JIANGSU BREE OPTRONICS CO LTD