Method for optimizing crystalline form of silicate green fluorescent powder material

A technology of green phosphor and silicate, applied in luminescent materials, chemical instruments and methods, etc., can solve the problems of unstable crystal shape, low sintering temperature of phosphor powder, and poor crystallization effect.

Inactive Publication Date: 2011-09-21
IRICO
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] The thermal extinction (Thermal Quenching Of Luminescence) or temperature stability of phosphors has always been valued by high-power white LEDs that are troubled by heat dissipation. Dr. Roth of the German company Litec pointed out that (Ba 1-x Sr x ) 2 SiO 4 :Eu 2+ Comparing the thermal extinction characteristics of silicate and YAG:Ce phosphors, the research results show that the thermal stability of the two phosphors is equal, but when the temperature is above 120°C, the thermal extinction of silicate is more obvious, and its thermal extinction is lower. One of the obvious reasons is that the sintering temperature of the phosphor powder in the silicate system is low and the crystal form is unstable. When it is in a high temperature state (above 120°C) for a long time, the crystallization effect is not good and the crystal shape is not good. resulting in poor thermal stability

Method used

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  • Method for optimizing crystalline form of silicate green fluorescent powder material
  • Method for optimizing crystalline form of silicate green fluorescent powder material
  • Method for optimizing crystalline form of silicate green fluorescent powder material

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Experimental program
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Embodiment 1

[0027] The first step is to synthesize the precursor of silicate green phosphor Sr 2 SiO 4 :

[0028] Weigh SrCO according to the molar ratio Sr:Si=2:1 3 147.61g, SiO 2 30.04, and grind it, mix it, and then add flux NH of 3wt% by weight of the mixture 4 Cl, put in an alumina crucible, place the crucible in a tube furnace, sinter at 1300°C for 3 hours in a protective gas, and then cool to obtain Sr 2 SiO 4 , the protective gas is nitrogen, and the gas flow rate is 15ml / min.

[0029] In the second step, in the prebody Sr 2 SiO 4 The provided matrix structure is doped with Ba element to synthesize the silicate green phosphor material BaSr 0.98 SiO 4 :0.02Eu:

[0030] According to BaSr 0.98 SiO 4 : The molar ratio of 0.02Eu element (Sr, Ba):Si:Eu=(1-0.02):1:0.02 Molar ratio weighs BaCO 3 5g, SiO 2 0.776g and Eu 2 o 3 0.089g, then the resulting Sr 2 SiO 4 After grinding and sieving, weigh 3.318g, and after grinding and mixing, add 5wt% of the total amount of ...

Embodiment 2

[0034] In order to show the advantages of the optimized silicate green phosphor material crystal form of the present invention, so the first two steps of embodiment 2 are consistent with embodiment 1, the difference is:

[0035] In step 1), Sr element may be Ca element, and Ca element is introduced into the system through its carbonate, nitrate or oxide. Add 2wt% or 4wt% co-solvent NH in the primary mixture to the total amount of the primary mixture 4 Cl; in protective gas Ar, N 2 / H 2 , NH 3 Sintering under one or a combination of several conditions, the gas flow rate is 20ml / min, the sintering temperature is 1000°C, and the sintering time is 4 hours.

[0036] In step 2), the Sr element may be Ca element, and the Ca element is introduced into the system through its carbonate, nitrate or oxide. Add the auxiliary solvent BaF that accounts for 3wt% or 4wt% of secondary mixture total amount in secondary mixture 2 ; in protective gas H 2 , N 2 / H 2 , NH 3 Sintering under ...

Embodiment 3

[0040] The first two steps of embodiment 3 are consistent with embodiment 1, and the parameters of the third step are changed emphatically to contrast with each embodiment.

[0041] The third step is to optimize the silicate green phosphor material BaSr 0.98 SiO 4 : The crystal morphology of 0.02Eu: the BaSr obtained in the second step 0.98 SiO 4 : 0.02Eu, after cooling, take out and grind, wash, dry, weigh and this sintered product BaSr 0.98 SiO 4 : 0.02Eu weight of 8% nitride Si 3 N 4 mixed grinding, where BaSr 0.98 SiO 4 :0.02Eu is 8.5g, Si 3 N 4 It is 0.425g, put into molybdenum crucible after above-mentioned each composition is ground, crucible is moved in the high-temperature tubular furnace, in N 2 :H 2 = Sintering at 1550°C for 10 hours in a 3:1 atmosphere, with a gas flow rate of 15ml / min, then cooling to room temperature, taking out, grinding and sieving, washing and drying with ethanol to obtain the silicate green phosphor material BaSr with optimized cry...

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Abstract

The invention discloses an optimized silicate green fluorescent powder material and an optimizing method thereof. The silicate green fluorescent powder material has a chemical general formula of (Ba,A)1-xSiO4:xEu, wherein x is more than 0 and less than 1.0, and A is an element Ca or Sr. The method comprises the following steps of: 1, synthesizing a precursor A2SiO4 of the silicate green fluorescent powder; 2, doping an element Ba in a matrix structure provided by the precursor A2SiO4 to synthesize the silicate green fluorescent powder material; and 3, optimizing a crystalline form of the silicate green fluorescent powder material. A crystallinity degree of the green fluorescent powder obtained with the optimizing method disclosed by the invention is greatly improved; the luminosity of the green fluorescent powder of the system is greatly strengthened; the crystalline form of the green fluorescent powder is greatly optimized, and the thermal stability of the green fluorescent powder of the system is improved.

Description

technical field [0001] The invention relates to a new method for optimizing the crystal form of a silicate green phosphor material, in particular to a preparation method for introducing a nitride into a silicate system to increase its sintering temperature and optimizing the crystal form of a silicate green phosphor material. Background technique [0002] The development of silicate phosphor originated from the Zn of General Electric (GE) in the early 1940s. 2 SiO 4 :Mn 2+ , through (Sr, Ba, Mg) 3 Si 2 o 7 :Pb 2+ (1949), BaSi 2 o 5 :Pb 2+ (1960), Sr 4 Si 3 o 8 Cl 4 :Eu 2+ (1967), BaSi 2 o 5 :Pb 2+ (1960) and other multi-material developments to 1998 (Ba, Si) 2 SiO 4 :Eu 2+ After the discovery of , the application of silicate phosphors in white light LEDs has progressed rapidly, and now there are many materials that can be used in white light LEDs. [0003] Silicate is an important new choice in the production of phosphor powder-converted white light LEDs,...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K11/79
Inventor 赵莉
Owner IRICO
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