Preparation method for LED (Light Emitting Diode) fluorescent powder

A technology of phosphor powder and alkaline earth metal, applied in the field of phosphor powder, can solve the problems that the color rendering index of the device is difficult to reach more than 80, hindering the development of white LED light-emitting devices, etc.

CN102329614AInactive Publication Date: 2012-01-25IRICO
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2012-01-25
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a novel preparation method for LED (Light Emitting Diode) fluorescent powder. The method comprises the following steps of: based on a chemical formula of Y4-x-yGdGa5R1-2O16:Ce<3+>xEu<2+>y, weighing yttrium oxide, gallium oxide, gadolinium oxide, alkaline earth, cerium oxide and europium oxide according to a molar ratio respectively, wherein X is equal to 0.05-0.10; Y is equal to 0.01-0.10; adding 1-8 percent of mixed fluxing agent including barium fluoride, cerium fluoride and yttrium fluoride to obtain a mixture; uniformly mixing the mixture in a mixer; filling in a baked corundum crucible; placing in a high-temperature furnace to heat; introducing nitrogen and hydrogen mixed gas or pure hydrogen as a reducing atmosphere; preserving heat; heating to bake; cooling and then crushing; and washing and then screening to obtain the LED fluorescent powder. The fluorescent powder has a wide wave spectrum range; and emission spectrum of 530-630nm can be obtained when the fluorescent powder is excited by light of 440-460nm.
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Description

technical field

[0001] The invention relates to a fluorescent powder which is suitable for excitation of 440nm-460nm light-emitting diode (LED) and can emit spectrum between 530nm-630nm. Background technique

[0002] Light-emitting diode is a new generation of green and environmentally friendly solid-state lighting green light source. It has low energy consumption, long life, small size, very stable structure, good light directivity, fast response, no radiation, and is suitable for harsh environments. At present, the main means of producing white light in light-emitting diodes (LEDs) is to excite YAG:Ce phosphor powder with blue light chips. But the emission spectrum of YAG:Ce phosphor is between 550nm and 560nm, so it cannot be combined with blue light chips to produce LED devices with positive white light (x, 0.333 y, 0.333) and low color warm tone (CCT≤5000K). In addition, the half peak width of YAG:Ce phosphor is relatively narrow, generally around 110nm, which makes it...

Examples

Embodiment 1

[0025] The present invention Y 3.93 GdGa 5 CaO 16 : Ce 3+ 0.04 Eu 2+ 0.03 Phosphor powder can be prepared using the following methods:

[0026] According to the above-mentioned general formula, weigh the yttrium oxide Y respectively according to the molar ratio 2 o 3 372.9g, gallium oxide Ga 2 o 3 468.5g, gadolinium oxide Gd 2 o 3 181.2g, calcium oxide CaO 88.0g, cerium oxide Ce 2 o 4 6.88g, europium oxide Eu 2 o 3 10.55g, add 3wt% of the above total amount of yttrium fluoride, cerium fluoride mixed flux according to the mass ratio of 2:3, mix and grind the mixture in the forced mixer for 30min, then put it into an alumina crucible and put it in a high-temperature furnace The volume ratio of nitrogen-hydrogen mixed gas into the inner 2 :H 2 = 3:1 reducing atmosphere, heat preservation at 1300°C for 2 hours, then heat up to 1650°C for 5 hours, keep the reducing atmosphere until natural cooling, and obtain phosphor. After high-temperature roasting and cooli...

Embodiment 2

[0029] The present invention Y 3.93 GdGa 5 CaO 16 : Ce 3+ 0.04 Eu 2+ 0.03 Small particle phosphors can be prepared using the following methods:

[0030] According to the above-mentioned general formula, weigh the yttrium oxide Y respectively according to the molar ratio 2 o 3 372.9g, gallium oxide Ga 2 o 3 468.5g, gadolinium oxide Gd 2 o 3 181.2g, calcium oxide CaO 88.0g, cerium oxide Ce 2 o 4 6.88g, europium oxide Eu 2 o 3 10.55g, add the above-mentioned yttrium fluoride, barium fluoride and cerium fluoride in a total amount of 8wt%, distribute the above three fluxes according to the mass ratio of 2:3:0.5, and mix them uniformly. After the above raw materials and flux are mixed evenly, the mixture is mixed and ground in a forced mixer for 30 minutes; the obtained mixture is put into a corundum crucible, and a nitrogen-hydrogen mixed gas with a volume ratio of N 2 :H 2 = 5:1 reducing atmosphere, heat preservation at 1300°C for 2 hours, then heat up to 1500°...

Embodiment 3

[0033] The present invention Y 3.85 GdGa 5 CaO 16 : Ce 3+ 0.05 Eu 2+ 0.1 Phosphor powder can be prepared using the following methods:

[0034] According to the above-mentioned general formula, weigh the yttrium oxide Y respectively according to the molar ratio 2 o 3 365.15g, gallium oxide Ga 2 o 3 468.5g, gadolinium oxide Gd 2 o 3 181.2g, calcium oxide Ca 2 o 3 88.0g, cerium oxide Ce 2 o 4 8.6g, europium oxide Eu 2 o 3 35.16g, add the above-mentioned yttrium fluoride, barium fluoride and cerium fluoride in an amount of 1wt%, distribute the above three fluxes according to the mass ratio of 2:3:0.5, and mix them evenly. After mixing the above raw materials and flux evenly, put the obtained mixture into a corundum crucible, pass pure hydrogen into a high-temperature furnace as a reducing atmosphere, keep it at 1300°C for 2 hours, and bake it at 1600°C for 7 hours, and keep the reducing atmosphere until After natural cooling, get Y 3.85 GdGa 5 CaO 16 : Ce ...