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Phosphor for white light LED and its prepn process

A phosphor and white light technology, applied in the field of white light LED, can solve the problems of inconvenient operation and high cost, and achieve the effect of wide excitation spectrum, broaden emission spectrum, and wide coverage of emitted light

Inactive Publication Date: 2010-03-24
SUN YAT SEN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] For the research on thioaluminate phosphors, Lethi, K.T et al. reported MS-Al in 1992 2 S 3 Incorporation of Eu into (M=Ca, Sr, Ba) system 2+ The luminescence property (Mat.Sci.Eng.B-Solid.1992,14,(4),393-397), but it adopts the reaction raw material to fill in the quartz ampoule bottle, and vacuumizes and seals the tube to synthesize, and it is expensive and inconvenient to operate ; And the existing synthesis all adopts more expensive and unstable aluminum trisulfide (Al 2 S 3 ) as the aluminum source, there is no report of using simple, economical and relatively stable aluminum powder (Al) as the aluminum source; in addition, other rare earths such as Ce 3+ The luminescent properties of doping have not been reported yet, and the application of this type of existing thioaluminate phosphors is mainly limited to the research of electroluminescent films, as Miura reported BaAl in 1999 2 S 4 :Eu 2+ quite bright blue electroluminescence (EL) film (J.Appl.Phys.2 1999, 38, (11B), L1291-L1292), and Nakua reported brighter CaAl in 2004 2 S 4 :Eu 2+ Green electroluminescent (EL) film (brightness up to 4200cd / m 2 at 260V) (Journal of the SID 11 / 3, 2003, 493), but the application of this kind of thioaluminate phosphor for LED has not been reported

Method used

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  • Phosphor for white light LED and its prepn process
  • Phosphor for white light LED and its prepn process
  • Phosphor for white light LED and its prepn process

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] (Ca 0.9 Eu 0.1 ) S Al 2 S 3 Synthesis of Phosphor Powder:

[0029] CaS: .0.1655g

[0030] Al: 0.1350g

[0031] Eu 2 o 3 : 0.0352g

[0032] S: 0.5000g

[0033] After grinding and mixing the raw materials of the mixture evenly, sintering at 1050°C for 1.5 hours in a hydrogen sulfide atmosphere, cooling, grinding evenly, and then crushing and sieving to finally obtain the product. figure 1 For the excitation and emission spectrum of the fluorescent powder, the excitation wavelength is 460nm.

[0034] White light LED packaging: mix the obtained phosphor powder with epoxy resin at a weight ratio of 1:2 to make a slurry, and then directly apply the slurry on the surface of the LED chip emitting blue light by coating, and finally cure it at 150°C, that is Get LED devices. Rare earth phosphors absorb light from blue LED chips and emit green light. Figure 4 It is the emission spectrum of the green LED with the change of driving current (5, 10, 20, 30, 40, 50mA).

Embodiment 2

[0036] (Zn 0.9 Eu 0.1 ) S Al 2 S 3 Synthesis of Phosphor Powder:

[0037] ZnS: 0.2192g

[0038] Al: 0.1350g

[0039] Eu 2 o 3 : 0.044g

[0040] S: 0.6000g

[0041] After grinding and mixing the raw materials of the mixture evenly, sintering at 980° C. for 3 hours in a hydrogen sulfide atmosphere, cooling, grinding evenly, and then crushing and sieving to finally obtain the product. figure 2 For the excitation and emission spectrum of the phosphor powder, the excitation wavelength is 400nm. Figure 5 The emission spectrum at room temperature of the green LED made of the fluorescent powder sealed tube of Example 2 at a driving current of 20 mA.

Embodiment 3

[0043] (Sr0.999 Ce 0.001 ) S Al 2 S 3 Synthesis of Phosphor Powder:

[0044] SrO: 0.3882g

[0045] Al: 0.2025g

[0046] CeO 2 : 0.0006g

[0047] S: 0.8000g

[0048] After grinding and mixing the raw materials of the mixture evenly, sintering at 1100°C for 2 hours in a hydrogen sulfide atmosphere, cooling, grinding evenly, and then crushing and sieving to finally obtain the product. image 3 For the excitation and emission spectrum of the phosphor powder, the excitation wavelength is 400nm.

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Abstract

The present invention discloses one kind of phosphor for white light LED and its preparation process. The phosphor has the chemical composition of m(M1-x-yRExAyS).n(Al2S3), where, M is at least one ofMg, Ca, Sr, Ba, Zn and Cd; RE is Ce and / or Eu; A is one selected from Mn, Pr, Sm, Tb and Dy; m and n are the molar number of the sulfides (M1-x-yRExAyS) and (Al2S3) separately, m is 1-5, n is 1 or 2;and x and y are the molar fractions of RE and A relative to M, x is 0.001-1 and y is 0-1. The phosphor is prepared with the corresponding simple substances or compounds and through compounding, grinding, calcining in reducing protection atmosphere, cooling, crushing and sieving. The phosphor, under the excitation of 300-500 nm light, can emit light in 420-700 nm, is suitable for use in near UV orblue light LED chip, and has high light emitting strength, wide exciting wavelength range and other features.

Description

technical field [0001] The invention relates to the field of white light LEDs, in particular to a fluorescent powder for white light LEDs and a preparation method thereof. Background technique [0002] Ga(In)N-based light-emitting diode (LED) is a new type of light-emitting device, which has the characteristics of small size, long life and energy saving, and is widely used in lighting and display fields. In recent years, with the rapid development of blue and near-ultraviolet LEDs, white light-emitting diodes are expected to replace fluorescent lamps as a new generation of light sources in the 21st century. [0003] At present, the method of LED to realize white light is mainly to coat the yellow phosphor powder that can be excited by blue light on the blue LED chip, and the blue light and yellow light are mixed to form white light; or to coat the blue LED chip that is excited by blue light to emit green light and Red light phosphor powder, red light, blue light, and green ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C09K11/84H01L33/00H01L33/50
Inventor 苏锵余瑞金王静张剑辉袁海滨
Owner SUN YAT SEN UNIV
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