CN103980902A - Ga-Bi doped aluminate green phosphor and preparation method thereof - Google Patents

Abstract

The invention relates to an aluminate green phosphor doped with rare earth elements gallium and bismuth, and a preparation method of the aluminate green phosphor. The aluminate green phosphor is activated by use of Ce<3+>, and the general formula of the aluminate green phosphor is Y3-x-nBinAl5-yGayO12: Ce<3+>x, wherein the numeric range of x is from 0.01 to 0.2, and preferably from 0.06 to 0.08; the numeric range of y is from 0.5 to 4.5, and preferably from 1.0 to 4.5; the numeric range of n is from 0 to 0.006, and preferably from 0.002 to 0.006. The phosphor having the main emission peak in the green position is obtained by doping YAG (Yttrium Aluminum Garnet) phosphor with the element Ga, and the overall luminous efficacy of the phosphor is not reduced; the green phosphor is matched with yellow phosphor and a blue LED (Light Emitting Diode) chip so that a high-brightness white-light LED can be obtained; if the green phosphor is matched with the blue LED chip, green light can be obtained directly; if the green phosphor is matched with the yellow phosphor and the blue LED chip, cold-tone white light can be obtained; the green phosphor also can be matched with red phosphor and the blue LED chip to obtain white light; and besides, trace bismuth element also can be added to the aluminate green phosphor, so that the luminous intensity of the prepared phosphor can be greatly improved.

Description

Aluminate green fluorescent powder of doping Ga, Bi and preparation method thereof

Technical field

The present invention relates to aluminate green fluorescent powder of a kind of doped with rare-earth elements gallium and bismuth and preparation method thereof, be particularly useful for blue chip and excite the LED green emitting phosphor of lower use, belong to rare earth luminescent material technical field.

Background technology

Photodiode (LED) is the New Solid illuminating device that development in recent years is got up, and has the advantages such as efficiency is high, the life-span long, pollution-free, energy-conservation.Be widely used in the every field such as liquid crystal screen backlight, pilot lamp, lamps for vehicle, electronics and indoor and outdoor lighting.Its use has far-reaching influence to the Sustainable development of energy-conserving and environment-protective and environment.

For general illumination, people more need white light source.The LED of white light in 1998 succeeds in developing, and this LED is packaged together GaN chip and yttrium aluminum garnet (YAG).GaN chip blue light-emitting (λ p=465nm, Wd=30nm), what high temperature sintering was made contains Ce³⁺yAG fluorescent material send sodium yellow after being subject to this blue-light excited and penetrate, peak value 550nm.Blue-ray LED substrate is arranged in bowl type reflection cavity, covers to be mixed with the thin resin layer of YAG, about 200-500nm.The blue light part that LED substrate sends is absorbed by fluorescent material, and the yellow light mix that another part blue light and fluorescent material send, obtains white light.The advantage of this combination is that luminous efficiency is high, and deficiency is to lack transmitting in ruddiness region, so the white light LEDs device colour rendering index of making is lower, colour temperature is higher.Current existing solution is to change YAG:Ce by ion substitution³⁺emission peak positions, red shift emission peak, but the deficiency of this mode is to have reduced the overall light efficiency of fluorescent material, is therefore badly in need of a kind of broad peak fluorescent material of launching the relative YAG:Ce3+ red shift of main peak of preparation, if transmitting main peak is at the fluorescent material of green position.

With green emitting phosphor cooperation yellow fluorescent powder and blue led chip, can obtain the white light LEDs of high brightness; If use green emitting phosphor to coordinate blue-light LED chip, can directly obtain green glow; If use green emitting phosphor to coordinate yellow fluorescent powder and blue led chip, can obtain cool tone white light; Green emitting phosphor also can coordinate red fluorescence powder and blue led chip and obtain white light.The colour rendering index (CRI) of white light LEDs is relevant with blue chip, YAG fluorescent material, correlated(color)temperature etc., wherein the most important thing is YAG fluorescent material, the LED in different-colour district, and the fluorescent material and the blue chip that use are different.The fluorescent material emission peak that the pipe that target colour temperature is lower is used is longer, the peak value of chip also will be grown, lower than 4000K colour temperature, also to add in addition the fluorescent material glowing, to make up the deficiency of red composition, reach and improve the object of colour rendering index, under the chip keeping and the constant condition of fluorescent material, colour temperature more high color rendering index (CRI) is higher.

Summary of the invention

The object of this invention is to provide one be suitable for LED with green emitting phosphor with and preparation method thereof, for realizing this object, technical scheme provided by the invention is:

The aluminate green fluorescent powder of this doping Ga, Bi, adopts Ce3+ to activate, and its general formula (1) is: Y_3-x-nbi_nal_5-yga_yo₁₂: Ce³⁺_x(1) wherein the span of x is 0.01 ~ 0.2, preferably 0.06 ~ 0.08; The span of y is 0.5 ~ 4.5, preferably 1.0 ~ 4.5; The span of n is 0 ~ 0.006, preferably 0.002 ~ 0.006.

The present invention, to the Ga element that adulterates in YAG fluorescent material, obtains launching the fluorescent material of main peak in green position, does not reduce the overall light efficiency of fluorescent material, coordinates yellow fluorescent powder and blue led chip with this green emitting phosphor, can obtain the white light LEDs of high brightness; If use this green emitting phosphor to coordinate blue-light LED chip, can directly obtain green glow; If use this green emitting phosphor to coordinate yellow fluorescent powder and blue led chip, can obtain cool tone white light; Also can coordinate red fluorescence powder and blue led chip and obtain white light; Also, by adding wherein micro-bismuth element, improve greatly the luminous intensity of the fluorescent material of preparing.

Particularly, it is 530nm ~ 510nm that the light of this green emitting phosphor is penetrated peak value, and this wave band is green light band.

The method of preparing the aluminate green fluorescent powder of this doping Ga, Bi, comprises the following steps:

A) take respectively aluminum oxide, yttrium oxide, cerium oxide, gallium oxide, bismuth oxide according to the stoichiometric ratio of general formula (1);

B) difference that obtains fluorescent material particle diameter size and wavelength according to plan is chosen different fusing assistants, and described fusing assistant is one or both in boric acid, aluminum fluoride, and the fusing assistant that accounts for 2-3% mole of general formula (1) is carried out crossing 200 eye mesh screens after dry bulb mill 1.5-2h;

C) starting material that a) and b) step obtains are put into biconical mixer and fully mix, mixing time is 25-30h;

D) mixture that c) step obtains is packed into crucible and puts into hyperthermia tunnel Kiln;

E) in hyperthermia tunnel Kiln, pass into the reducing atmosphere of hydrogen: nitrogen=3:1, at 1580 DEG C, constant temperature burns 4.5h;

F) head product that e) step obtains is taken out from crucible, be down to after room temperature, first carry out coarse breaking with excellent pestle, then roller pair breaking;

G) head product that f) step obtains is washed after 5 times with the deionized water of 90 DEG C, put into baking oven and dry;

H) head product that g) step obtains is crossed to 200 eye mesh screens, packaging, obtains finished product.

Burn because the present invention only carries out a high temperature to raw material, thereby the sintered material hardness of powder obviously reduces, the powder agglomates of sintering is loose, has not only reduced technological process, and save energy and quality product go up not down; Fusing assistant is carried out to ball-milling processing in advance, the Ball-milling Time of head product is greatly reduced, thereby increased the crystal brightness of the finished product.

Embodiment

Embodiment 1:

An adulterate aluminate green fluorescent powder of Ga, its chemical formula is Y_2.93al_3.1ga_1.9o₁₂: Ce³⁺_0.07.

A) accurately take the Y of 487.2g₂o₃, 232.2g Al₂o₃, 262.2g Ga₂o₃, 17.7g CeO₂;

B) accurately take 20g aluminum fluoride and carry out crossing 200 eye mesh screens after dry bulb mill 2h;

C) starting material that a) and b) step obtains are put into biconical mixer and fully mix, mixing time is 25h;

D) mixture that c) step obtains is packed into crucible and puts into hyperthermia tunnel Kiln;

E) in hyperthermia tunnel Kiln, pass into the reducing atmosphere of hydrogen: nitrogen=3:1, at 1580 DEG C, constant temperature burns 4.5h;

F) head product that e) step obtains is taken out from crucible, be down to after room temperature, first carry out coarse breaking with excellent pestle, then roller pair breaking;

G) head product that f) step obtains is washed after 5 times with the deionized water of 90 DEG C, put into baking oven and dry;

H) head product that g) step obtains is crossed to 200 eye mesh screens, packaging, obtains finished product.

Embodiment 2:

An adulterate aluminate green fluorescent powder of Ga, Bi, chemical formula is Y_2.925bi_0.005al_3.1ga_1.9o₁₂: Ce³⁺_0.071.

A) accurately take the Y of 485.9g₂o₃, 232.5g Al₂o₃, 262.0g Ga₂o₃, 17.1g CeO₂, 1.71g Bi₂o₃

B) accurately take 20g boric acid and carry out crossing 200 eye mesh screens after dry bulb mill 1.5h;

C) starting material that a) and b) step obtains are put into biconical mixer and fully mix, mixing time is 30h;

D) mixture that c) step obtains is packed into crucible and puts into hyperthermia tunnel Kiln;

E) in hyperthermia tunnel Kiln, pass into the reducing atmosphere of hydrogen: nitrogen=3:1, at 1580 DEG C, constant temperature burns 4.5h;

F) head product that e) step obtains is taken out from crucible, be down to after room temperature, first carry out coarse breaking with excellent pestle, then roller pair breaking;

G) head product that f) step obtains is washed after 5 times with the deionized water of 90 DEG C, put into baking oven and dry;

H) head product that g) step obtains is crossed to 200 eye mesh screens, packaging, obtains finished product.

Embodiment 3:

An adulterate aluminate green fluorescent powder of Ga, chemical formula is Y_2.93al_1.2ga_3.8o₁₂: Ce³⁺_0.07.

A) accurately take the Y of 435.1g₂o₃, 80.4g Al₂o₃, 468.4g Ga₂o₃, 15.8g CeO₂;

B) accurately take 10g aluminum fluoride and 10g boric acid and carry out crossing 200 eye mesh screens after dry bulb mill 1.8h;

C) starting material that a) and b) step obtains are put into biconical mixer and fully mix, mixing time is 27h;

D) mixture that c) step obtains is packed into crucible and puts into hyperthermia tunnel Kiln;

E) in hyperthermia tunnel Kiln, pass into the reducing atmosphere of hydrogen: nitrogen=3:1, at 1580 DEG C, constant temperature burns 4.5h;

F) head product that e) step obtains is taken out from crucible, be down to after room temperature, first carry out coarse breaking with excellent pestle, then roller pair breaking;

G) head product that f) step obtains is washed after 5 times with the deionized water of 90 DEG C, put into baking oven and dry;

H) head product that g) step obtains is crossed to 200 eye mesh screens, packaging, obtains finished product.

Embodiment 4:

An adulterate aluminate green fluorescent powder of Ga, Bi, chemical formula is Y_2.925bi_0.005al_1.2ga_3.8o₁₂: Ce³⁺_0.071.

A) accurately take the Y of 434.0g₂o₃, 80.4g Al₂o₃, 468.1g Ga₂o₃, 15.8g CeO₂, 1.53g Bi₂o₃;

B) accurately take 20g aluminum fluoride and carry out crossing 200 eye mesh screens after dry bulb mill 1.6h;

C) starting material that a) and b) step obtains are put into biconical mixer and fully mix, mixing time is 26h;

D) mixture that c) step obtains is packed into crucible and puts into hyperthermia tunnel Kiln;

E) in hyperthermia tunnel Kiln, pass into the reducing atmosphere of hydrogen: nitrogen=3:1, at 1580 DEG C, constant temperature burns 4.5h;

F) head product that e) step obtains is taken out from crucible, be down to after room temperature, first carry out coarse breaking with excellent pestle, then roller pair breaking;

G) head product that f) step obtains is washed after 5 times with the deionized water of 90 DEG C, put into baking oven and dry;

H) head product that g) step obtains is crossed to 200 eye mesh screens, packaging, obtains finished product.

Comparative example:

A undope aluminate green fluorescent powder of Ga and Bi, chemical formula is Y_2.925al_1.2o₁₂: Ce³⁺_0.071.

A) accurately take the Y of 434.0g₂o₃, 80.4g Al₂o₃, 15.8g CeO₂;

B) accurately take 20g aluminum fluoride and carry out crossing 200 eye mesh screens after dry bulb mill 1.6h;

C) starting material that a) and b) step obtains are put into biconical mixer and fully mix, mixing time is 26h;

D) mixture that c) step obtains is packed into crucible and puts into hyperthermia tunnel Kiln;

E) in hyperthermia tunnel Kiln, pass into the reducing atmosphere of hydrogen: nitrogen=3:1, at 1580 DEG C, constant temperature burns 4.5h;

F) head product that e) step obtains is taken out from crucible, be down to after room temperature, first carry out coarse breaking with excellent pestle, then roller pair breaking;

G) head product that f) step obtains is washed after 5 times with the deionized water of 90 DEG C, put into baking oven and dry;

H) head product that g) step obtains is crossed to 200 eye mesh screens, packaging, obtains finished product.

Embodiment 1-4 and comparative example are carried out to performance test, obtain data as follows:

X Y is CIE chromaticity coordinates

Sample	Emission peak (nm)	CIE chromaticity coordinates X	CIE chromaticity coordinates Y	Luminous intensity
					Comparative example	558	0.435	0.545	100
Embodiment 1	535	0.385	0.556	88
					Embodiment 2	535	0.385	0.556	96
Embodiment 3	520	0.351	0.567	84
					Embodiment 4	520	0.351	0.567	92

As can be seen from the above table, it is more that the emission peak of the YAG of the Ga that undopes exceeds green wave band 530nm ~ 510nm, but luminous intensity is good; Doping Ga YAG emission peak near or be positioned between green wave band 530nm ~ 510nm, luminous intensity declines to some extent, but doping Bi after luminous intensity have a distinct increment.

Claims (3)

1. the aluminate green fluorescent powder of doping Ga, Bi, adopts Ce³⁺activate, its general formula (1) is: Y_3-x-nbi_nal₅-_yga_yo₁₂: Ce³⁺_x(1) wherein the span of x is 0.01 ~ 0.2, preferably 0.06 ~ 0.08; The span of y is 0.5 ~ 4.5, preferably 1.0 ~ 4.5; The span of n is 0 ~ 0.006, preferably 0.002 ~ 0.006.

2. the aluminate green fluorescent powder of doping Ga, Bi according to claim 1, is characterized in that it is 530nm ~ 510nm that its light is penetrated peak value.

3. the method for the aluminate green fluorescent powder of preparation doping claimed in claim 1 Ga, Bi, comprises the following steps:

A) take respectively aluminum oxide, yttrium oxide, cerium oxide, gallium oxide, bismuth oxide according to the stoichiometric ratio of general formula (1);

B) difference that obtains fluorescent material particle diameter size and wavelength according to plan is chosen different fusing assistants, and described fusing assistant is one or both in boric acid, aluminum fluoride, and the fusing assistant that accounts for 2-3% mole of general formula (1) is carried out crossing 200 eye mesh screens after dry bulb mill 1.5-2h;

C) starting material that a) and b) step obtains are put into biconical mixer and fully mix, mixing time is 25-30h;

D) mixture that c) step obtains is packed into crucible and puts into hyperthermia tunnel Kiln;

E) in hyperthermia tunnel Kiln, pass into the reducing atmosphere of hydrogen: nitrogen=3:1, at 1580 DEG C, constant temperature burns 4.5h;

F) head product that e) step obtains is taken out from crucible, be down to after room temperature, first carry out coarse breaking with excellent pestle, then roller pair breaking;

G) head product that f) step obtains is washed after 5 times with the deionized water of 90 DEG C, put into baking oven and dry;

H) head product that g) step obtains is crossed to 200 eye mesh screens, packaging, obtains finished product.