CN102504814B

CN102504814B - Direct white light fluorescent material excited by ultraviolet light and preparation method and application thereof

Info

Publication number: CN102504814B
Application number: CN2011103212200A
Authority: CN
Inventors: 毛智勇; 祝迎春
Original assignee: Shanghai Institute of Ceramics of CAS
Current assignee: Jiangsu Institute Of Advanced Inorganic Materials
Priority date: 2011-10-20
Filing date: 2011-10-20
Publication date: 2013-11-20
Anticipated expiration: 2031-10-20
Also published as: CN102504814A

Abstract

The invention discloses a direct white light fluorescent material excited by ultraviolet light, a preparation method and application thereof. The material is a composite material composed of yellow fluorescent powder and amorphous glass phase. The amorphous glass phase is coated on the particle surface of yellow fluorescent powder and is formed by heat treatment of nano oxide and yellow fluorescent powder. The preparation of the material is to weigh the yellow fluorescent powder and the nanometer oxide in proportion, mix them evenly, place them in a boron nitride crucible, conduct heat treatment in a nitrogen atmosphere, cool them, and grind them. Since the fluorescent material provided by the invention is a single fluorescent material capable of simultaneously emitting blue light and yellow light, it can be applied to ultraviolet-based white light LEDs and white light-emitting devices excited by mercury discharge ultraviolet light. In addition, the invention not only has a simple preparation process and is suitable for large-scale production, but also can obtain direct white light emission with different color temperatures, and has industrial application prospects and value.

Description

Direct white fluorescence material of a kind of ultraviolet excitation and its preparation method and application

Technical field

The present invention relates to direct white fluorescence material of a kind of ultraviolet excitation and its preparation method and application, belongs to the photoelectric material technical field.

Background technology

Under global low-carbon (LC), energy-conservation overall background, the illumination of efficient reduce power consumption, show that white light parts has received the very big concern of various countries.Europe, Japan announce to adopt electricity-saving lamp or white light LEDs to replace the incandescent light of high energy consumption in succession.Incandescent light is a kind of heat radiation light source, and 95% energy is that the form with heat has lost.And electricity-saving lamp and white light LEDs are cold light sources, have characteristics, particularly white light LEDs efficient, reduce power consumption and also have the advantages such as long service life, pollution-free, volume is little.Electricity-saving lamp and white light LED part are all under a kind of irradiation of short-wavelength light, by fluor light, are converted to white light emission.For example electricity-saving lamp is the ultraviolet ray excited three primary colors fluorescent powder of with mercury vapor discharge, emitting, and white light LEDs modal be to excite yellow fluorescent powder with the InGaN blue chip.

Usually need to excite three kinds of fluorescent material of red, green, blue with the ultraviolet LED chip in order to obtain the high-color rendering low color temperature white light LED.Yet, adopt so the mixed light conversion of white light technology of many components fluor to come with some shortcomings, such as: the specific refractory power of each composition fluorescent grain of micron order is inconsistent, causes the propagation attenuation of photon energy between different crystalline lattice; The absorption of each composition fluor, excitation and emission spectra, light decay and efficiency are inconsistent, cause the colour stability of device poor; Directly there is the re-absorbed problem of light in each component fluorescent powder particle; And complicated blending processes of powders problem.For above-mentioned background, adopt direct white light (single-phase panchromatic or single-phase white) fluorescent material can effectively overcome the problem that mixed whitewash light technology exists, be a kind of innovation to the mixed whitewash light technology of tradition.Therefore the research that is used for the direct white fluorescence material of burst of ultraviolel of white light LEDs and electricity-saving lamp becomes a study hotspot of field of light emitting materials and has obtained research widely.

The reported direct white fluorescence material of single-phase that is suitable for ultraviolet excitation has a lot, and for example: it is Ca that a kind of its ingredient formula is provided in the Chinese invention patent of application number for CN200910087495 _1-xPr _xMO ₄The white emitting fluorescent powder of single component, under the exciting of single excitaton source, lighting system can be sent the white light of low colour temperature; A kind of preparation method of ultraviolet excitation single white phosphors is provided in the Chinese invention patent of application number for CN 200710170433, and the structural formula of fluorescent material is Sr _1-xEu _xZn _2-yMn (PO ₄) ₂It is Eu that a kind of expression formula is provided in the Chinese invention patent of application number for CN 200510016743 _xySr _Y-xyMgSi _zO _2x+y+1White emitting fluorescent powder.Can find out from prior art, at present the color matching strategy of transmitting white and the research of material system are variation, indigo plant based on multiple luminescence center+direct white light emission system of yellow two waveband is wherein arranged; Based on Eu ²⁺-Mn ²⁺Red+green+blue (or indigo plant+Huang) of mixing altogether transmission ofenergy be white light emission system directly; Whole color fluorescent material based on electronic migration between the conjugate rare earth ion pair; Synthesize based on original position the direct white light emission that accompanying impurities is realized mutually; Based on direct white fluorescence material system that mixes valency Eu codoped etc.Industrial community and each large research institution have given great attention to the direct white fluorescence material of burst of ultraviolel, particularly with the direct white fluorescence material of ultraviolet chips incorporate, by industry, are thought to obtain the developing direction of high-color rendering, white light LED part that colour temperature is adjustable.

Summary of the invention

The technical problem to be solved in the present invention is to provide direct white fluorescence material of a kind of ultraviolet excitation and its preparation method and application.

For solving the problems of the technologies described above, the technical solution used in the present invention is as follows:

A kind of direct white fluorescence material of ultraviolet excitation, it is a kind of matrix material by yellow fluorescent powder and amorphous glass phase composite, described amorphous glass is coated on the particle surface of yellow fluorescent powder mutually, is to be formed through thermal treatment by nano-oxide and yellow fluorescent powder.

Further, the composition general formula of described yellow fluorescent powder is Ca _m/2Si _12-m-nAl _m+nO _nN _16-n: Eu _x, 0＜m wherein≤3,0＜n≤1.5,0.005≤x≤0.2.

Further, the composition general formula of described yellow fluorescent powder is Ca _1-xSi ₉Al ₃ON ₁₅: Eu _x, 0.005≤x wherein≤0.2.

Further, described nano-oxide is nanometer SiO ₂, nanometer A1 ₂O ₃, nanometer B ₂O ₃In any one or a few mixture.

A kind of preparation method of direct white fluorescence material of described ultraviolet excitation, comprise the steps: to take in proportion yellow fluorescent powder and nano-oxide, evenly mixes and be placed in boron nitride crucible, heat-treats in nitrogen atmosphere, and is cooling, grinds.

The mass ratio of described yellow fluorescent powder and nano-oxide is recommended as 1: 0.01～and 1: 2, be preferably 1: 0.1～1: 1.

Described heat-treat condition is recommended as at 1200～1500 ℃ and processed 30～100 minutes.

Due to material of the present invention under the exciting of the UV-light of 250～420nm, can launch simultaneously the blue light of 380～460nm and the orange light of 470～600nm, and then be mixed into white light, for direct white fluorescence material, therefore, can be applicable in the white light emitting device of ultraviolet base white light LEDs and mercury discharge ultraviolet excitation.

Because fluorescent material provided by the invention is a kind of single fluorescent material that can launch simultaneously blue light and gold-tinted; therefore than adopting ultraviolet excitation red, green, blue or indigo plant, the mixed whitewash light prior art of yellow multiple fluorescent material on micro-meter scale; the light that can overcome between different fluorescent powder grains heavily absorbs and the complicated defect problems such as blending processes of powders; not only technique is simple; be fit to large-scale production; and can obtain the direct white light emission of different-colour, have prospects for commercial application and value.

Description of drawings

Fig. 1 is the yellow fluorescent powder (Ca of the different Eu doping contents of embodiment 1 preparation _1-xSi ₉Al ₃ON ₁₅: Eu _x, x=0.02,0.04,0.06,0.08,0.10) and emmission spectrum under the ultraviolet excitation of 365nm;

Fig. 2 is the emmission spectrum of the direct white fluorescence material that forms of the difference of embodiment 2 preparation;

Fig. 3 is the XRD diffracting spectrum that embodiment 3 yellow fluorescent powder used reaches the direct white fluorescence material for preparing at the different heat treatment temperature;

Fig. 4 is the TEM of the direct white fluorescence material for preparing of embodiment 3, HRTEM photo and EDS ultimate analysis collection of illustrative plates.

Fig. 5 is excitation spectrum and the emmission spectrum that embodiment 3 yellow fluorescent powder used reaches the direct white fluorescence material for preparing at the different heat treatment temperature;

Fig. 6 is the chromaticity coordinates figure that embodiment 3 yellow fluorescent powder used reaches the direct white fluorescence material for preparing at the different heat treatment temperature;

Fig. 7 is the emmission spectrum that embodiment 4 yellow fluorescent powder used reaches the direct white fluorescence material for preparing under the time in different heat treatment;

Fig. 8 is the SEM photo of embodiment 5 yellow fluorescent powder used (a) and the direct white fluorescence material (b) for preparing.

Embodiment

The progress of substantive distinguishing features of the present invention and significance is described below in conjunction with specific embodiments and the drawings.Should be understood that these embodiment only are used to further illustrate the present invention, and can not be interpreted as limiting the scope of the invention.The experimental technique of unreceipted actual conditions in the following example,, usually according to normal condition, be for example the condition in workshop manual, or the condition of advising according to manufacturer.

Embodiment 1

According to Ca _1-xSi ₉Al ₃ON ₁₅: Eu _xThe stoichiometric ratio of (x=0.02,0.04,0.06,0.08,0.10) accurately takes CaCO ₃, Si ₃N ₄, AlN, Eu ₂O ₃, after evenly mixing in grinding as for agate, in the dislocation boron nitride crucible, the concrete weight of various raw materials is as shown in table 1; Then boron nitride crucible is placed in high frequency furnace,, in 1700 ℃ of sintering reactions 2 hours, obtains the yellow fluorescent powder of different Eu doping contents after naturally cooling under nitrogen protection atmosphere, be designated as: Ca-SiAlON:Eu ²⁺

Table 1

Chemical formula	CaCO ₃(g)	Si ₃N ₄(g)	AlN(g)	Eu ₂O ₃(g)
					Ca _0.98Si ₉Al ₃ON ₁₅:Eu _0.02	0.0901	1.7534	0.9225	0.0176
Ca _0.96Si ₉Al ₃ON ₁₅:Eu _0.04	0.1802	1.7534	0.9225	0.0352
					Ca _0.94Si ₉Al ₃ON ₁₅:Eu _0.06	0.2703	1.7534	0.9225	0.0528
Ca _0.92Si ₉Al ₃ON ₁₅:Eu _0.08	0.3604	1.7534	0.9225	0.0704
					Ca _0.90Si ₉Al ₃ON ₁₅:Eu _0.10	0.4504	1.7534	0.9225	0.0880

Fig. 1 is the yellow fluorescent powder (Ca of the prepared different Eu doping contents of the present embodiment _1-xSi ₉Al ₃ON ₁₅: Eu _xX=0.02,0.04,0.06,0.08,0.10) and utilizing emitted light spectrogram under the ultraviolet excitation of 365nm, as seen from Figure 1: along with the increase of Eu doping content, red shift has occurred in the emission peak of sample, has moved to the orange light of 575nm of doped parameterx=0.10 from the 555nm yellow green light of doped parameterx=0.02.

By the present embodiment, the yellow fluorescent powder that can obtain different emission by the doping content that changes Eu can be described.

Embodiment 2

The Ca that embodiment 1 is obtained _0.98Si ₉Al ₃ON ₁₅: Eu _0.02Yellow fluorescent powder and nano-oxide (SiO ₂, Al ₂O ₃, B ₂O ₃) in one or more evenly mix by certain mass ratio, concrete mass ratio is as shown in table 2; Material after mixing is put into boron nitride crucible, processes 45 minutes in 1200 ℃ under nitrogen protection atmosphere in high frequency furnace.After naturally cooling, namely obtain the direct white fluorescence material of ultraviolet excitation.

Table 2

Sequence number	Ca _0.98Si ₉Al ₃ON ₁₅:Eu _0.02(g)	SiO ₂(g)	Al ₂O ₃(g)	B ₂O ₃(g)
					1	0.200	0	0	0
2	0.200	0	0	0.065
					3	0.200	0	0.075	0
4	0.200	0.075	0	0
					5	0.200	0	0.075	0.065
6	0.200	0.075	0.065	0
					7	0.200	0	0.040	0.052
8	0.200	0.075	0.075	0.065

Fig. 2 is the utilizing emitted light spectrogram of the direct white fluorescence material of the prepared difference composition of the present embodiment, as seen from Figure 2: do not add the sample of nano-oxide, show the luminosity of yellow fluorescent powder; But added the sample of nano-oxide, blue emission peak in various degree occurred in 400～480nm zone, with Ca _0.98Si ₉Al ₃ON ₁₅: Eu _0.02Yellow emission mix, and then obtain direct white light.

Can be illustrated by the present embodiment, the fluorescent material that the present invention obtains can be launched blue light and gold-tinted simultaneously under the exciting of UV-light, and then mixes the acquisition white light, is direct white fluorescence material.

Embodiment 3

Take 0.60 gram Ca _0.98Si ₉Al ₃ON ₁₅: Eu _0.02Yellow fluorescent powder and 0.225 gram nanometer SiO ₂Be divided into 3 parts after evenly mixing and put into 3 boron nitride crucibles, processed 45 minutes respectively at 1200 ℃, 1300 ℃, 1400 ℃ under nitrogen protection atmosphere in high frequency furnace, after naturally cooling, obtain direct white fluorescence material.

Fig. 3 is the XRD diffracting spectrum that the present embodiment yellow fluorescent powder used reaches the direct white fluorescence material for preparing at the different heat treatment temperature; As seen from Figure 3: Ca _0.98Si ₉Al ₃ON ₁₅: Eu _0.02Yellow fluorescent powder is typical Ca-SiAlON structure, and the direct white fluorescence material that obtains under subzero treatment still keeps the Ca-SiAlON structure,, along with the increase of thermal treatment temp, a small amount of Si occurred ₂N ₂The diffraction peak of O impurity phase.The intensity step-down of the diffraction peak of the sample after all are processed, the degree of crystallinity of interpret sample reduces, and has in other words occurred the amorphous glass phase in sample, has formed yellow Ca-SiAlON fluorescent material and amorphous glass phase composite materials.

Fig. 4 is the TEM of the direct white fluorescence material for preparing of the present embodiment, HRTEM photo and EDS ultimate analysis collection of illustrative plates.Can be found out by HRTEM, coat the obvious amorphous glass phase of one deck on the crystal grain surface, the electron diffraction analysis result shows that crystal grain is Ca-SiAlON crystalline phase (being the yellow fluorescent powder that we prepare).Find by the crystal grain of inside and the constituency EDS ultimate analysis of surface coated amorphous glass layer, their composition is all Ca-Si-Al-O-N, and this explanation amorphous glass is not by nanometer SiO mutually ₂Simply be coated on the particle surface of fluorescent material, but form after the phase mutual diffusion with the fluorescent powder grain surface is incorporated into.In addition, the Si-O composition of amorphous glass phase will be higher than composition corresponding to the crystalline phase of inside, and this formation that amorphous glass phase just has been described is due to SiO ₂Incorporate into and cause.

Fig. 5 is excitation spectrum and the utilizing emitted light spectrogram that the present embodiment yellow fluorescent powder used reaches the direct white fluorescence material for preparing at the different heat treatment temperature; As seen from Figure 5: along with the rising of thermal treatment temp, the direct white fluorescence material for preparing strengthens at the blue-light-emitting peak of 400～480nm, at the Yellow luminous peak of 480～600nm, reduces.When thermal treatment temp was 1400 ℃, the blue emission peak of the direct white fluorescence material for preparing accounted for leading; From excitation spectrum, the excitation spectrum of blue emission and the excitation spectrum of yellow emission have well overlapping in 250～400nm UV-light zone, illustrate that the material of preparation can be launched blue light and gold-tinted simultaneously with ultraviolet excitation, and then mix the acquisition white light.

Fig. 6 is the chromaticity coordinates figure that the present embodiment yellow fluorescent powder used reaches the direct white fluorescence material for preparing at the different heat treatment temperature; As seen from Figure 6: Ca _0.98Si ₉Al ₃ON ₁₅: Eu _0.02The chromaticity coordinates of yellow fluorescent powder drops on the gold-tinted zone, and along with the rising of thermal treatment temp, directly the chromaticity coordinates of white fluorescence material moves toward white light field.When thermal treatment temp is 1300 ℃, the chromaticity coordinates of the direct white fluorescence material for preparing is (0.33,0.36), near equal-energy white luminous point (0.33,0.33), and when thermal treatment temp was 1400 ℃, the chromaticity coordinates of the direct white fluorescence material for preparing had moved to blue white light field, illustrated that the blue light ingredient of this moment is too much.

Can be illustrated by regulating thermal treatment temp by the present embodiment, can obtain to have the direct white fluorescence material of different Photochromic Properties.

Embodiment 4

Take 0.60 gram Ca _0.98Si ₉Al ₃ON ₁₅: Eu _0.02Yellow fluorescent powder and 0.225 gram nanometer SiO ₂, be divided into 3 parts after evenly mixing and put into 3 boron nitride crucibles, processed respectively 30 minutes, 45 minutes, 60 minutes in 1300 ℃ under nitrogen protection atmosphere in high frequency furnace, after naturally cooling, obtain direct white fluorescence material.

Fig. 7 is the utilizing emitted light spectrogram that the present embodiment yellow fluorescent powder used reaches the direct white fluorescence material for preparing under the time in different heat treatment, as seen from Figure 7: along with the increase of heat treatment time, the blue emission peak of the direct white fluorescence material for preparing strengthens, and the yellow emission peak weakens, and the color quality that can change white light emission by regulating heat treatment time is described.

Embodiment 5

Take 0.20 gram Ca _0.98Si ₉Al ₃ON ₁₅: Eu _0.02Yellow fluorescent powder and 0.07 gram nanometer B ₂O ₃, evenly mix and be placed in boron nitride crucible,, in 1400 ℃ of processing 30 minutes, after naturally cooling, obtain direct white fluorescence material under the high frequency furnace nitrogen protection atmosphere.

Fig. 8 is the SEM photo of the present embodiment yellow fluorescent powder used (a) and the direct white fluorescence material (b) for preparing, as seen from Figure 8: Ca _0.98Si ₉Al ₃ON ₁₅: Eu _0.02The yellow fluorescent powder grain diameter is 2～3 micron left and right, and about 5 microns left and right of the grain diameter of the direct white fluorescence material for preparing, this is that to be coated on mutually the yellow fluorescent powder particle surface caused due to the phase mutual diffusion between nano-oxide and yellow fluorescent powder surface and the amorphous glass of incorporating formation into.

Claims

1. A direct white light fluorescent material excited by ultraviolet light, characterized in that: it is a composite material composed of a yellow phosphor powder and an amorphous glass phase, and the amorphous glass phase is coated on the particle surface of the yellow phosphor powder , which is formed by heat treatment of nano-oxide and yellow phosphor; the general formula of the yellow phosphor is Ca _1-x Si ₉ Al ₃ ON ₁₅ : _Eux , where 0.005≤x≤0.2; the The nano-oxide is any one or a mixture of nano-SiO ₂ , nano-Al ₂ O ₃ , and nano-B ₂ O ₃ ; the mass ratio of yellow phosphor to nano-oxide is 1:0.1 to 1:1; The heat treatment conditions described above are 30-100 minutes at 1200-1500°C.

2. A method for preparing a direct white light fluorescent material excited by ultraviolet light according to claim 1, characterized in that it comprises the steps of: taking yellow phosphor powder and nano-oxide in proportion, placing them in boron nitride after uniform mixing Crucible, heat treatment in nitrogen atmosphere, cooling, grinding.

3. The application of the direct white light fluorescent material excited by ultraviolet light in claim 1 in ultraviolet-based white light LED.

4. The application of the ultraviolet-light-excited direct white-light fluorescent material of claim 1 in a mercury-discharge ultraviolet-light-excited white light-emitting device.