Rare-earth-free fluorescent powder for white light LED and preparation method of rare-earth-free fluorescent powder

A rare-earth-free and phosphor-free technology, which is applied in the field of rare-earth-free phosphors for white LEDs and its preparation, can solve the problems of inconsistent aging characteristics and temperature characteristics, changes in white LED color characteristics, and high color temperature of white light LEDs, and achieve color rendering index Improvement, low light attenuation, high light efficiency

Inactive Publication Date: 2016-06-22
ZHEJIANG UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the lack of emission of the red part of the YAG:Ce phosphor, the white LED produced by it has the disadvantages of high color temperature and low color rendering index.
At present, in order to obtain white LEDs with high color rendering index, a common solution is to add a certain amount of re

Method used

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  • Rare-earth-free fluorescent powder for white light LED and preparation method of rare-earth-free fluorescent powder

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] (1) Preparation of metal-organic framework materials:

[0026] Weigh 1mmol of 1,3,5-tris(4-carboxybenzene)benzene and 3mmol of indium chloride and dissolve them in a mixed solvent of 60mL of N,N-dimethylformamide, 40mL of dioxane and 50mL of water, Then add 0.5 mL of nitric acid with a mass fraction of 65%, stir evenly, put it into a closed reaction kettle, and heat it to 130 o C constant temperature reaction 24h, obtain metal-organic framework material;

[0027] (2) Yellow or green light-emitting dyes and red light-emitting dyes loaded into metal-organic framework materials:

[0028] Dissolve 5 mg of the green light-emitting dye coumarin 6 and 0.5 mg of the red light-emitting dye pyronin B in 100 mL of N,N dimethylformamide solvent, and then add 1 g of the metal-organic The frame material is soaked for 24 hours, filtered, washed with ethanol, and dried to obtain a rare-earth-free phosphor for white LEDs.

[0029] The phosphor contains 99.74wt% of metal-organic frame...

Embodiment 2

[0031] (1) Preparation of metal-organic framework materials:

[0032] Weigh 1mmol of 1,3,5-tris(4-carboxybenzene)benzene and 3mmol of indium chloride and dissolve them in a mixed solvent of 60mL of N,N-dimethylformamide, 40mL of dioxane and 50mL of water, Then add 0.5 mL of nitric acid with a mass fraction of 65%, stir evenly, put it into a closed reaction kettle, and heat it to 130 o C constant temperature reaction 24h, obtain metal-organic framework material;

[0033] (2) Yellow or green light-emitting dyes and red light-emitting dyes loaded into metal-organic framework materials:

[0034] Dissolve 5 mg of the green light-emitting dye coumarin 6 and 0.3 mg of the red light-emitting dye pyronin B in 100 mL of N,N dimethylformamide solvent, and then add 1 g of the metal-organic The frame material is soaked for 24 hours, filtered, washed with ethanol, and dried to obtain a rare-earth-free phosphor for white LEDs.

[0035] The phosphor contains 99.77wt% metal-organic framewor...

Embodiment 3

[0037] (1) Preparation of metal-organic framework materials:

[0038] Weigh 1mmol of 5-amino-isophthalic acid and 3mmol of aluminum chloride and dissolve them in a mixed solvent of 60mL of ethanol and 10mL of water, put them into a closed reaction kettle, and heat to 40 o C constant temperature reaction 5h, obtain metal-organic framework material;

[0039] (2) Yellow or green light-emitting dyes and red light-emitting dyes loaded into metal-organic framework materials:

[0040] Dissolve 5 mg of the yellow-emitting dye fluorescein and 0.5 mg of the red-emitting dye Rhodamine B in 100 mL of water, then add 0.8 g of the metal-organic framework material prepared in step (1) to soak for 24 hours, filter and wash with ethanol, After drying, the rare-earth-free phosphor powder for white light LEDs is obtained.

[0041]The fluorescent powder contains 99.45wt% of metal-organic framework material, 0.31wt% of fluorescein, and 0.24wt% of rhodamine B, and its internal quantum efficiency ...

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Abstract

The invention discloses rare-earth-free fluorescent powder for a white light LED and a preparation method of the rare-earth-free fluorescent powder. The rare-earth-free fluorescent powder is prepared from, by mass, 98-99.98% of metal-organic frame material, 0.01-1% of yellow light or green light emission dyestuff and 0.01-1% of red light emission dyestuff. The preparation method includes the following steps that an aromatic carboxylic acid organic ligand and metal salt are subjected to solvothermal/hydrothermal reaction synthesis to obtain the metal-organic frame material; the metal-organic frame material is soaked in a dyestuff solution, and dyestuff molecules/ions enter the metal-organic frame material. The process is simple, conditions are mild, the yield is high, the prepared fluorescent powder is free of a rare earth element, internal quantum efficiency is higher than 75%, and thermo-chemical stability is high. The rare-earth-free fluorescent powder is combined with a blue light LED chip, the color rending index of the prepared white light LED is higher than 80, the color temperature can be continuously adjusted between 2,500 K and 7,000 K, brightness is high, and under injection at the current density of 20 A/cm<2>, the lighting efficiency is higher than 140 lm/W, and luminous decay is low.

Description

technical field [0001] The invention relates to a rare-earth-free fluorescent powder and a preparation method thereof, in particular to a rare-earth-free fluorescent powder for white LEDs and a preparation method thereof. Background technique [0002] Due to its high luminous efficiency, long life, small devices, and fast response, white LEDs have developed rapidly in the past decade and are considered to be solid-state light sources that can replace incandescent and fluorescent lamps. There are many ways to realize white LED. Currently, the most mainstream way is that blue LED chip excites yellow phosphor to form white light. This solution has the advantages of simple design and high lumen efficiency. The current yellow phosphor mainly uses cerium-doped yttrium aluminum garnet (YAG:Ce) phosphor, which emits a broad-spectrum emission of about 540nm under the excitation of 450-460nm blue light, and is combined with the blue light emitted by the chip. get white light. Howeve...

Claims

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Application Information

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IPC IPC(8): C09K11/06
CPCC09K11/06C09K2211/183C09K2211/186C09K2211/188Y02B20/00
Inventor 钱国栋宋涛崔元靖
Owner ZHEJIANG UNIV
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