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Red fluorescent powder for white radiation LED and preparation thereof

A technology for red phosphor powder and white light, applied in the field of red phosphor powder and its preparation, can solve the problems of low luminous efficiency, high sintering temperature and high production cost, and achieve the effects of simple preparation method, good radiation resistance and low cost

Inactive Publication Date: 2009-01-14
JIANGSU TIWIN OPTO ELECTRONICS TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although their luminous color is pure, there are two main disadvantages: one is the high price of raw material yttrium oxide and europium oxide, which leads to high production cost, and the sintering temperature during synthesis is as high as 1300 ° C, which wastes energy
The second is that the luminous efficiency is very low under the excitation of near ultraviolet light (or blue light), only green powder (ZnS:Cu + , Al 3+ ) and blue powder (BaMgAl 10 o 17 :Eu 2+ ), and the lifespan is shorter than that of green powder and blue powder

Method used

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  • Red fluorescent powder for white radiation LED and preparation thereof
  • Red fluorescent powder for white radiation LED and preparation thereof
  • Red fluorescent powder for white radiation LED and preparation thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] The chemical expression of the red fluorescent powder of the present embodiment is:

[0019] Li 0.30 K 1.70 SM 0.022 Bi 0.90 (P 0.96 Nb 0.04 o 4 )(W 0.37 Mo 0.63 o 4 ):0.07gEu 3+ Its preparation method is as follows:

[0020] ①Weigh 1.12g of Li 2 CO 3 , 3.70g of K 2 CO 3 , 0.40g of Sm 2 o 3 , 20.97g Bi 2 o 3 , 13.10g of KH 2 PO 4 , 0.55g of Nb 2 o 5 , 10.0g of (NH 4 ) 6 W 7 o 24 ·6H 2 O, 12.35g of (NH 4 ) 2 MoO 4 and 1.40g of Eu 2 o 3 and researched separately. The above raw materials are analytically pure, and the purity of the rare earth oxide is 99.99%.

[0021] ②Mix the above raw materials evenly, then place them in an oven to fully dry to remove water, and grind them again.

[0022] ③Put the mixed material into a corundum crucible and put it into a muffle furnace, and sinter at 680°C for 6h in an air atmosphere.

[0023] ④ The obtained sintered product is crushed, powder-selected, acid-washed, alkali-washed, water-washed, then dri...

Embodiment 2～ Embodiment 10

[0025] See Table 1 for the chemical expressions of the red phosphors of Examples 2 to 10. Their preparation methods are basically the same as in Example 1, and the differences are also shown in Table 1.

[0026] Table 1

[0027]

[0028] Connect to Table 1

[0029] Example 7

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Abstract

The invention discloses red fluorescent powder used for a white LED. The chemical expression is that R<1>2R<2>1-x(R<3>O4) (R<4>O4) : xEu<3+>, wherein, R<1> is one, two or more of Li<+>, Na<+>, K<+>, Rb<+> and Ag<+>; R<2> is one, two or more of La<3+>, Gd<3+>, Y<3+>, Pr<3+>, Sm<3+>, Eu<3+>, Bi<3+>, B<3+> and Al<3+>; R<3> is P<5+>, P<5+> and V<5+>, P<5+> and Nb<5+>, or P<5+> and V<5+> as well as Nb<5+>; R<4> is W<6+> and Mo<6+>; x is 0.005 to 1.0. The preparation method of the red fluorescent powder comprises the following steps: firstly, raw material containing R<1>, R<2>, Eu<3+>, R<3> and R<4> is porphyrized and evenly mixed, dried and porphyrized again and positioned into a muffle to be sintered; secondly, the red fluorescent powder is obtained after post-processing. The red fluorescent powder of the invention can be effectively excitated by blue light, black light or ultraviolet light, the light and thermal stability is good, the red luminous intensity is high, and the color purity is ideal.

Description

technical field [0001] The invention relates to a red fluorescent powder and a preparation method thereof, in particular to a red fluorescent powder for white LEDs and a preparation method thereof. Background technique [0002] At present, the activator used in red phosphor powder for white light LED is based on divalent europium ion (Eu 2+ ) and europium ions (Eu 3+ ) mainly. Eu 2+ Ions are important rare earth activators, but because their 5d electrons are "bare" and are strongly affected by the surrounding crystal field environment, when doped into different matrix compounds, the main emission peaks vary greatly, and the luminescence Color varies with substrate. In addition, in order to maintain the corresponding valence state, a reducing protective atmosphere such as a mixed gas of 95% nitrogen and 5% hydrogen or ammonia must be used in the synthesis process. This limits the Eu 2+ Used as an activator for red phosphors. Currently, the commercial red phosphors for ...

Claims

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Application Information

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IPC IPC(8): C09K11/78H01L33/00H01L33/50
Inventor 贺香红
Owner JIANGSU TIWIN OPTO ELECTRONICS TECH
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