A kind of white light LEDs is with adjustable fluorescent material of emission peak and preparation method thereof
Technical field
The present invention relates to a kind of fluorescent material, especially relate to and a kind ofly can effectively excited and glow by ultraviolet, purple light or blue-ray LED, and another emission peak that when burst of ultraviolel, occurs adjustable rare-earth luminescent material and preparation method thereof from ruddiness to the green glow.
Background technology
Light-emitting diode LED (Light? Emitting? Diode) is a kind of can convert electrical energy into light energy conversion devices with low voltage, low power consumption, stable performance, long life, impact resistance, vibration resistance, weight Light and luminous fast response, etc., so the display, general lighting, lights and signal lights and other fields have a wide range of applications (Xu Shu Rong, SU Mian-Zeng. luminescence and luminescent materials [M]. Beijing: Chemical Industry Press, 2004).
At present, the realization of white light LEDs mainly contains two types: first type is with 3 kinds of LED combination results of red, green, blue white light; Second type is to mix with other luminescent material of LED de excitation to form white light, can effectively be excited and the fluorescent material of the light that turns to be yellow by blue-ray LED, and blue light and yellow light mix form white light; Or on blue-light LED chip, apply can be by blue-light excited and fluorescent material transmitting green light and ruddiness, and ruddiness, blue light and green glow mix the formation white light; Or on purple light or ultraviolet LED chip, apply efficiently 3 kinds of fluorescent material of red, green, blue and realize white light LEDs.See from present development trend; At aspects such as feasibility, practicality and commercializations; Second type is better than first type, one of critical material that therefore synthetic fluorescent material with good luminous performance is the realization white light LEDs (Chinese patent 200310113506.5).
At present, the research and development of adopting gan (GaN) blue-ray LED (emission peak is 460nm) to cooperate YAG to produce the fluorescent material of white light has obtained bigger progress, though technology is quite ripe, the blue-ray LED luminous efficiency is low.The current effective efficiency of conversion of fluorescent material that can be applicable to white light LEDs is lower, can't satisfy the requirement of high performance device, especially the kind of red fluorescence powder seldom, efficient lower (Chinese patent 03149752.7).USP has been reported several kinds of sulfide red fluorescent material; Its fluorescence spectrum broad, but poor stability produce the look drift in device uses; Therefore; The white light LEDs of development of new becomes the focus (United States Patent, 2000, Patent No.:6252254) of domestic and international research with the fluorescent material of red-emitting.In recent years; The molybdate fluorescent material is in the ascendant as the research of white light LEDs aspect; But it is narrower that it excites with the halfwidth of emission peak; Influence its application (Yunsheng Hu, Weidong Zhuang, Hongqi Ye. " A novel red phosphorfor white light emitting diodes " [J] Journal of Alloys and Compounds 390 (2005): 226-229) aspect white light LEDs.
Summary of the invention
The object of the present invention is to provide a kind of chemical property stable, good luminous performance can effectively be excited and glows by ultraviolet, purple light or blue-ray LED, and when burst of ultraviolel another emission peak from ruddiness to the green glow adjustable white light LEDs with the adjustable fluorescent material of emission peak.
Another object of the present invention is to provide that a kind of method is simple, easy handling, low, the free of contamination a kind of white light LEDs of equipment cost be with the adjustable fluorescent material preparation method of emission peak.
A kind of white light LEDs of the present invention uses the structural formula of the adjustable fluorescent material of emission peak to be: A
1-x(W
1-yMo
y) O
4: Eu
x, wherein, A is Li, Na, K, Mg, Ca, Sr, at least a among the Ba; 0<x≤0.35,0≤y≤1.
A kind of white light LEDs of the present invention is following with its step of preparation method of the adjustable fluorescent material of emission peak:
1) oxide compound or the salt to contain the A element contains oxide compound or the salt of W, Mo, contains Eu
2+Oxide compound or salt be raw material, and add fusing assistant H
3BO
3, mix mixture, the consumption of each raw material is pressed stoichiometric equation A
1-x(W
1-yMo
y) O
4: Eu
xThe mol ratio that (0<x≤0.35,0≤y≤1) requires takes by weighing fusing assistant H
3BO
3Consumption be can get fluorescent material total mass 2%~5%;
2) mixture is heat-treated the thermal treatment postcooling under electric furnace air atmosphere;
3) thermal treatment, cooled product are carried out aftertreatment, the aftertreatment flow process comprises pulverizing, removal of impurities, oven dry, classification.
The oxide compound of raw material A element or salt contain oxide compound or the salt of W, Mo, contain Eu
2+Oxide compound or salt, preferably grind>=100 orders, grinding can be carried out in ethanol, acetone soln.
Thermal treatment temp is preferably 1000~1100 ℃, and heat treatment time is preferably 2~3h, after the thermal treatment in stove naturally cooling.
The removal of impurities process comprises at least a in pickling, alkali cleaning and the washing; Bake out temperature is 80~100 ℃; Classification process can adopt at least a in the methods such as settling process, method of sieving, hydraulic classification or air classification.
A kind of white light LEDs of the present invention has following outstanding characteristics with the adjustable fluorescent material of emission peak:
1, performance is highly stable, and through bubble, heat processing such as (below 400 ℃), the luminescent properties of fluorescent material does not change basically;
2, effectively excited by ultraviolet, purple light or blue-ray LED and glowing, changing the x value and can realize that the luminous intensity that glows is adjustable.Change another emission peak that occurs when the y value can be implemented in burst of ultraviolel and can move to green glow (545nm), and the burst of ultraviolel wavelength region is wide, luminous intensity is high, good stability from ruddiness (597nm);
3, simple, the easy handling of preparation method, equipment cost are low, pollution-free.
4. have wide range of applications, for example: 1), be used, be coated on the blue-light LED chip, can realize novel white light LEDs with green emitting phosphor at the blue-light excited ruddiness that produces about 614nm down of 450~500nm wave band; 2) at the purple light excited ruddiness that produces about 614nm down of 360~420nm wave band, be used, be coated on the purple LED chip, can make novel white light LEDs with green emitting phosphor; 3) under the burst of ultraviolel of 250~320nm wave band, produce ruddiness and the adjustable light of 597~545nm wave band of about 614nm, the fluorescent material of other type of remix produces the color LED of various colors.
Description of drawings
Fig. 1 is Ca
0.85WO
4: Eu
0.15Excitation spectrum.In Fig. 1, X-coordinate is excitation peak wavelength Wavelength (nm), and ordinate zou is luminous intensity Intensity (a.u.).Each excitation spectrum is respectively 260nm from left to right, 394nm, 464nm, λ
Em=614nm.
Fig. 2 is Ca
0.85WO
4: Eu
0.15Emmission spectrum.In Fig. 2, X-coordinate is emission peak wavelength Wavelength (nm), and ordinate zou is luminous intensity Intensity (a.u.).Each emmission spectrum is distinguished 591nm, 614nm, dotted line λ from left to right
Em=UV, solid line λ
Em=464nm.
Fig. 3 is (Ca
0.5Mg
0.35) (W
0.8Mo
0.2) O
4: Eu
0.15Excitation spectrum.In Fig. 3, X-coordinate is excitation peak wavelength Wavelength (nm), and ordinate zou is luminous intensity Intensity (a.u.).Each excitation spectrum is respectively 264nm from left to right, 394nm, 464nm, λ
Em=614nm.
Fig. 4 is (Ca
0.5Mg
0.35) (W
0.8Mo
0.2) O
4: Eu
0.15Emmission spectrum.In Fig. 4, X-coordinate is emission peak wavelength Wavelength (nm), and ordinate zou is luminous intensity Intensity (a.u.).Each emmission spectrum is distinguished 591nm, 597nm, 614nm, dotted line λ from left to right
Em=UV, solid line λ
Em=464nm.
Fig. 5 is (Ca
0.5Sr
0.35) (W
0.5Mo
0.5) O
4: Eu
0.15Excitation spectrum.In Fig. 5, X-coordinate is excitation peak wavelength Wavelength (nm), and ordinate zou is luminous intensity Intensity (a.u.).Each excitation spectrum is respectively 293nm from left to right, 394nm, 464nm, λ
Cm=614nm.
Fig. 6 is (Ca
0.5Sr
0.35) (W
0.5Mo
0.5) O
4: Eu
0.15Emmission spectrum.In Fig. 6, X-coordinate is emission peak wavelength Wavelength (nm), and ordinate zou is luminous intensity Intensity (a.u.).Each emmission spectrum is distinguished 598nm, 591nm, 614nm, dotted line λ from left to right
Em=UV, solid line λ
Em=464nm.
Fig. 7 is (Ca
0.5Ba
0.35) (W
0.2Mo
0.8) O
4: Eu
0.15Excitation spectrum.In Fig. 7, X-coordinate is excitation peak wavelength Wavelength (nm), and ordinate zou is luminous intensity Intensity (a.u.).Each excitation spectrum is respectively 272nm from left to right, 394nm, 614nm, λ
Cm=614nm.
Fig. 8 is (Ca
0.5Ba
0.35) (W
0.2Mo
0.8) O
4: Eu
0.15Emmission spectrum.In Fig. 8, X-coordinate is emission peak wavelength Wavelength (nm), and ordinate zou is luminous intensity Intensity (a.u.).Each emmission spectrum is distinguished 545nm, 591nm, 614nm, dotted line λ from left to right
Em=UV, solid line λ
Em=464nm.
Fig. 9 is Ca
0.85MoO
4: Eu
0.15Excitation spectrum.In Fig. 9, X-coordinate is excitation peak wavelength Wavelength (nm), and ordinate zou is luminous intensity Intensity (a.u.).Each excitation spectrum is respectively 260nm from left to right, 394nm, 464nm, λ
Cm=614nm.
Figure 10 is Ca
0.85MoO
4: Eu
0.15Emmission spectrum.In Figure 10, X-coordinate is emission peak wavelength Wavelength (nm), and ordinate zou is luminous intensity Intensity (a.u.).Each emmission spectrum is distinguished 591nm, 614nm, dotted line λ from left to right
Em=UV, solid line λ
Em=464nm.
Embodiment
Embodiment 1
Ca
0.85WO
4: Eu
0.1The preparation of 5 fluorescent material, the practical implementation process is following:
Mol ratio by above-mentioned stoichiometric equation takes by weighing CaCO
3(AR) 1.7015g, WO
3(AR) 4.6370g, Eu
2O
3(4N) 0.5282g, H
3BO
3(AR) 0.3433g.After fully grinding above-mentioned raw materials evenly, the alumina crucible of packing into, thermal treatment 3h in 1000 ℃ of air atmospheres.It is Ca that the thermal treatment product is promptly got chemical composition through pulverizing, washing removal of impurities, filtration, 90 ℃ of oven dry
0.85WO
4: Eu
0.15Red fluorescence powder.Its excitation spectrum is seen Fig. 1, and emmission spectrum is seen Fig. 2, and fluorescence data is seen table 1.Can know that by chart data this fluorescent material can effectively be excited by the ultraviolet in 250~480nm scope, purple light or blue light.
The stoichiometric equation of table 1 instance 1~5 and fluorescence data thereof
Embodiment 2
(Ca
0.5Mg
0.35) (W
0.8Mo
0.2) O
4: Eu
0.15The preparation of fluorescent material, the practical implementation process is following:
Mol ratio by above-mentioned stoichiometric equation takes by weighing CaCO
3(AR) 0.8508g, (MgCO
3) .Mg (OH)
2.5H
2O (AR) 0.6801g, (AR) WO
3(AR) 3.7096g, MoO
3(AR) 0.5758g, Eu
2O
3(4N) 0.5282g, H
3BO
3(AR) 0.3172g.After fully grinding above-mentioned raw materials evenly, the alumina crucible of packing into, thermal treatment 2.5h in 1050 ℃ of air atmospheres.It is Ca that the thermal treatment product is promptly got chemical composition through pulverizing, pickling impurity removal, filtration, 100 ℃ of oven dry
0.85(W
0.8Mo
0.2) O
4: Eu
0.15Red fluorescence powder.Its excitation spectrum is seen Fig. 3, and emmission spectrum is seen Fig. 4, and fluorescence data is seen table 1.Can know that by chart data this fluorescent material can effectively be excited by the ultraviolet in 250~480nm scope, purple light or blue light.
Embodiment 3
(Ca
0.5Sr
0.35) (W
0.5Mo
0.5) O
4: Eu
0.15The preparation of fluorescent material, the practical implementation process is following:
Mol ratio by above-mentioned stoichiometric equation takes by weighing CaCO
3(AR) 0.8508g, SrCO
3(AR) 1.0333g, WO
3(AR) 2.3185g, MoO
3(AR) 1.4394g, Eu
2O
3(4N) 0.5282g, H
3BO
3(AR) 0.3085g.After fully grinding above-mentioned raw materials evenly, the alumina crucible of packing into, thermal treatment 2h in 1100 ℃ of air atmospheres.It is Ca that the thermal treatment product is promptly got chemical composition through pulverizing, alkali cleaning and washing removal of impurities, filtration, 80 ℃ of oven dry
0.85(W
0.5Mo
0.5) O
4: Eu
0.15Red fluorescence powder.Its excitation spectrum is seen Fig. 5, and emmission spectrum is seen Fig. 6, and fluorescence data is seen table 1.Can know that by chart data this fluorescent material can effectively be excited by the ultraviolet in 250~480nm scope, purple light or blue light.
Embodiment 4
(Ca
0.5Ba
0.35) (W
0.2Mo
0.8) O
4: Eu
0.15The preparation of fluorescent material, the practical implementation process is following:
Mol ratio by above-mentioned stoichiometric equation takes by weighing CaCO
3(AR) 0.8508g, BaCO
3(AR) 1.3813g, WO
3(AR) 0.9274g, MoO
3(AR) 2.3030g, Eu
2O
3(4N) 0.5282g, H
3BO
3(AR) 0.2995g.After fully grinding above-mentioned raw materials evenly, the alumina crucible of packing into, thermal treatment 2.5h in 1050 ℃ of air atmospheres.It is Ca that the thermal treatment product is promptly got chemical composition through pulverizing, alkali cleaning removal of impurities, filtration, 85 ℃ of oven dry
0.85(W
0.2Mo
0.8) O
4: Eu
0.15Red fluorescence powder.Its excitation spectrum is seen Fig. 7, and emmission spectrum is seen Fig. 8, and fluorescence data is seen table 1.Can know that by chart data this fluorescent material can effectively be excited by the ultraviolet in 250~480nm scope, purple light or blue light.
Embodiment 5
Ca
0.85MoO
4: Eu
0.15The preparation of fluorescent material, the practical implementation process is following:
Mol ratio by above-mentioned stoichiometric equation takes by weighing CaCO
3(AR) 1.7015g, MoO
3(AR) 2..8788g, Eu
2O
3(4N) 0.5282g, H
3BO
3(AR) 0.2554g.After fully grinding above-mentioned raw materials evenly, the alumina crucible of packing into, thermal treatment 3h in 1000 ℃ of air atmospheres.It is Ca that the thermal treatment product is promptly got chemical composition through pulverizing, washing and alkali cleaning removal of impurities, filtration, 95 ℃ of oven dry
0.85MoO
4: Eu
0.15Red fluorescence powder.Its excitation spectrum is seen Fig. 9, and emmission spectrum is seen Figure 10, and fluorescence data is seen table 1.Can know that by chart data this fluorescent material can effectively be excited by the ultraviolet in 250~480nm scope, purple light or blue light.
In sum; A kind of white light LEDs of the present invention has that chemicalstability is good, luminous intensity is high, can effectively be excited by the ultraviolet in 250~480nm scope, purple light or blue light with the adjustable fluorescent material of emission peak, and regulates the W/Mo ratio and can realize the characteristics such as mobile of emission peak between ruddiness and green glow.The preparation method is simple, easy handling, equipment cost are low, pollution-free.