阅读说明：本技术 一种陶瓷-玻璃复合结构荧光色轮及其制备方法和在激光显示源中的应用 (Ceramic-glass composite structure fluorescent color wheel, preparation method thereof and application thereof in laser display source ) 是由 邾强强 殷召敏 王乐 翟玥 张宏 于 2021-07-20 设计创作，主要内容包括：本发明提供一种陶瓷-玻璃复合结构荧光色轮及其制备方法和在激光显示源中的应用。该陶瓷-玻璃复合结构荧光色轮由连续相多孔绿色发光荧光陶瓷基质及分布于其气孔中的红色发光荧光玻璃组成。在蓝色激光光源的激发下,连续相高导热荧光陶瓷会产生绿色发光,并保证荧光色轮优良的散热性能,而分布于气孔中的红色荧光玻璃则不仅可以提供红光波段的发光,还可以在保证红色氮化物荧光粉发光性能的前提下将其分散到陶瓷基质中。通过蓝色激光激发该陶瓷-玻璃复合结构荧光色轮,可实现高亮度红、绿、蓝三基色发光,满足激光显示对广色域、高亮度光源的应用需求。(The invention provides a ceramic-glass composite structure fluorescent color wheel, a preparation method thereof and application thereof in a laser display source. The ceramic-glass composite structure fluorescent color wheel consists of a continuous phase porous green luminous fluorescent ceramic matrix and red luminous fluorescent glass distributed in pores of the matrix. Under the excitation of a blue laser light source, the continuous phase high-heat-conductivity fluorescent ceramic can generate green luminescence and ensure the excellent heat dissipation performance of the fluorescent color wheel, and the red fluorescent glass distributed in the air holes can not only provide luminescence of a red light wave band, but also disperse the red nitride fluorescent powder into a ceramic substrate on the premise of ensuring the luminescence performance of the red nitride fluorescent powder. The ceramic-glass composite structure fluorescent color wheel is excited by blue laser, so that high-brightness red, green and blue three-primary-color luminescence can be realized, and the application requirements of laser display on a wide-color-gamut and high-brightness light source are met.)

1. The ceramic-glass composite structure fluorescent color wheel is characterized by comprising a continuous phase porous green luminous fluorescent ceramic matrix and red luminous fluorescent glass distributed in pores of the matrix.

2. The ceramic-glass composite structure fluorescent color wheel of claim 1, wherein the porous green luminescent fluorescent ceramic matrix has a porosity of 5-40% and a pore diameter of 5-30 μm.

3. The ceramic-glass composite structure fluorescent color wheel according to claim 1 or 2, wherein the porous green luminescent ceramic matrix is a green luminescent phosphor single phase structure or a green luminescent phosphor and Al₂O₃A complex phase structure;

the green luminescent phosphor is YAGG to Ce or LuAG to Ce.

4. The ceramic-glass composite structure fluorescent color wheel as claimed in claim 3, wherein the mass percentage of the green emitting phosphor in the composite structure is 20-40%.

5. The ceramic-glass composite structure fluorescent color wheel as claimed in claim 1, wherein the red luminescent glass is a mixed phase of red luminescent phosphor and glass powder.

6. The ceramic-glass composite fluorescent color wheel of claim 5, wherein the red-emitting phosphor is Ca_1-xEu_xAlSiN₃Phosphor powder, 0<x≤0.5, wherein the mass percent of the red luminescent fluorescent powder in the red luminescent fluorescent glass is 40-60%.

7. The method for preparing a ceramic-glass composite structure fluorescent color wheel according to any of claims 1-6, characterized by comprising the steps of:

a) mixing green emitting phosphor and Al₂O₃Mixing the powder, performing dry pressing to obtain a ceramic blank, and sintering the ceramic blank at a high temperature to obtain a porous green luminescent fluorescent ceramic matrix;

b) mixing red luminescent fluorescent powder and glass powder in absolute ethyl alcohol through ball milling to obtain fluorescent glass slurry, then putting the porous green luminescent fluorescent ceramic substrate obtained in the step a) into the fluorescent glass slurry for soaking, and sintering the fluorescent ceramic substrate absorbed with the red luminescent fluorescent powder and the glass powder at low temperature after the absolute ethyl alcohol is completely volatilized to obtain the ceramic-glass composite structure fluorescent color wheel.

8. The preparation method according to claim 7, wherein in the step a), the sintering of the ceramic body is a reducing atmosphere normal pressure sintering, the sintering temperature is 1200-1600 ℃, the holding time is 1-5 hours, and the sintering atmosphere is nitrogen or nitrogen/hydrogen mixed gas.

9. The preparation method according to claim 7, wherein in the step b), the low-temperature sintering is a reducing atmosphere normal-pressure sintering, the sintering temperature is 400-800 ℃, the holding time is 5-30 minutes, and the sintering atmosphere is nitrogen or a nitrogen/hydrogen mixed gas.

10. Use of the ceramic-glass composite fluorescent color wheel according to any of claims 1-6 in a laser display source.

Technical Field

The invention relates to the field of novel display light source materials, in particular to a fluorescent color wheel with a ceramic-glass composite structure for laser display application and a preparation method thereof.

Background

Compared with the traditional LCD liquid crystal display, the laser display shows remarkable potential advantages in a series of performance indexes. In a laser display system, the most important core component is a light source portion in addition to an imaging system. At present, a laser display light source is mainly realized by combining three primary colors of lasers (namely red, green and blue lasers), but the method has the problems of high cost, difficult speckle elimination, difficult performance matching of lasers with different colors and the like (T.T.K.tran, et al., App.optics,2016,55(6): 1267-. In order to avoid the bottleneck problem caused by three primary colors laser, another technical scheme of adopting blue laser to excite a fluorescent material (blue laser and fluorescent material) is provided, namely fluorescent laser display, because only blue laser is used in the scheme, the cost is obviously reduced, the matching problem between lasers with different colors is avoided, decoherence is not needed, and the fluorescent laser display light source becomes the best alternative scheme for realizing the laser display light source at present.

In the above-mentioned fluorescent laser display technology, the core technology of the laser display light source is a fluorescent color wheel, which is a core factor determining the key performance of the laser display terminal, such as brightness, color gamut, and lifetime. Because a strong thermal effect is generated when the high-energy laser is excited, in order to ensure the luminous efficiency and the working stability of the laser display light source, the fluorescent color wheel is required to have excellent heat dissipation performance and high-temperature stability. The conventional solid-state lighting packaging material (such as organic resin) not only has low thermal conductivity, but also has yellowing phenomenon under long-time and high-power excitation light irradiation, thereby causing the deterioration of the performance of the whole lighting device. The fluorescent ceramic material has excellent thermal conductivity and high-temperature stabilityThe fields of light display and illumination show good application advantages. Until now, white light sources for laser displays (based on fluorescent color wheels) have been excited, like white LED sources, mainly by blue light, to yellow YAG: Ce³⁺Fluorescent ceramics, but the lack of red and green light components in the light source causes the problem of low color rendering/gamut of the final laser light source (c.cozzan, et al., ACS appl.mater.inter.,2018(10): 5673-.

In the conventional LED white light source technology, a nitride red phosphor (CaAlSiN) is usually added₃:Eu²⁺) The method of (3) realizes the improvement of the red light component of the light source. But the nitride fluorescent material uses Si₃N₄As a raw material, and Si₃N₄The diffusion coefficient of the nitride fluorescent ceramic material is low, so that the nitride fluorescent ceramic material with good performance is difficult to directly prepare by using raw materials. Meanwhile, because the high temperature stability of the nitride fluorescent material is poor, the nitride fluorescent powder is difficult to disperse into a corresponding ceramic matrix by using a complex phase ceramic synthesis technology on the premise of ensuring the luminescent performance of the nitride fluorescent powder [ Li S, et al, J.Mater.chem.C,2016,4(35):8197-8205 ].]. Currently, in order to realize the application of red luminescent nitride fluorescent material in the laser display and illumination fields, the red luminescent nitride fluorescent material is usually compounded with a glass matrix to prepare a fluorescent glass material [ Zhu Q, et al, J.Alloy.Compd.,2017,702:193-]Or prepared into a fluorescent glass film [ Jianan Xu, et. J. Eur. Ceram. Soc.,2020,40(13):4704-]. But due to the low thermal conductivity of the glass matrix (1 Wm)^-1K^-1) And heat generated during high-power laser excitation is difficult to dissipate quickly, so that the luminous efficiency of the red luminous nitride fluorescent glass is low, and the current red nitride fluorescent material is difficult to meet the application requirement of laser display on a high-brightness light source.

Disclosure of Invention

In order to solve the problems, the invention provides a fluorescent color wheel with a ceramic-glass composite structure, a preparation method thereof and application thereof in a laser display source.

The ceramic-glass composite structure fluorescent color wheel comprises a continuous phase porous green luminous fluorescent ceramic matrix and red luminous fluorescent glass distributed in pores of the matrix.

The porosity of the fluorescent ceramic matrix in the ceramic-glass composite structure fluorescent color wheel provided by the invention is 5-40%, preferably 10-20%, and the diameter of the pores is 5-30 micrometers, preferably 10-20 micrometers; the fluorescent ceramic matrix is Y_{3- x}Ce_xAl_5-yGa_yO₁₂(0<x is less than or equal to 0.5, preferably less than or equal to 0.05 and less than or equal to 0.14 and 0<y<5, preferably 1. ltoreq. y. ltoreq.3) or Lu_3-xCe_xAl₅O₁₂(0<x is less than or equal to 0.5, preferably 0.05 is less than or equal to 0.14) single-phase structure or corresponding fluorescent powder and Al₂O₃The composite structure is preferably fluorescent powder and Al₂O₃The fluorescent powder has a complex phase structure, and the mass percentage of the fluorescent powder is 10-50%, preferably 20-40%.

The red luminous fluorescent glass in the ceramic-glass composite structure fluorescent color wheel provided by the invention is CaAlSiN₃:Eu(Ca_1-xEu_xAlSiN₃，0<x is less than or equal to 0.5, preferably 0.05 is less than or equal to 0.14) and the mixed phase of the fluorescent powder and the glass powder, wherein the mass percent of the fluorescent powder is between 30 and 70 percent, preferably between 40 and 60 percent.

The invention also provides a preparation method of the ceramic-glass composite structure fluorescent color wheel, which comprises the following steps:

a) mixing green emitting phosphor and Al₂O₃Mixing the powder, performing dry pressing to obtain a ceramic blank, and sintering the ceramic blank at a high temperature to obtain a porous green luminescent fluorescent ceramic matrix;

b) the red luminous fluorescent powder and the glass powder are mixed in absolute ethyl alcohol through ball milling to obtain fluorescent glass slurry, then the fluorescent ceramic substrate is placed in the fluorescent glass slurry for soaking, and after the absolute ethyl alcohol is completely volatilized, the fluorescent ceramic substrate absorbed with the red luminous fluorescent powder and the glass powder is sintered at low temperature to obtain the fluorescent color wheel with the ceramic-glass composite structure.

In the step a), the sintering of the ceramic blank is a reducing atmosphere normal pressure sintering, the sintering temperature is 1200-1600 ℃, the preferable sintering temperature is 1300-1400 ℃, the heat preservation time is 1-5 hours, the preferable sintering time is 2-3 hours, and the sintering atmosphere is nitrogen or nitrogen/hydrogen mixed gas, and the preferable nitrogen/hydrogen mixed gas. Further preferably, the sintering temperature is 1300-1400 ℃, the heat preservation time is 3-4 hours, and the sintering atmosphere is nitrogen or nitrogen/hydrogen mixed gas.

The solid content of the fluorescent glass slurry in the step b) is between 5 and 50 vol%, preferably between 20 and 30 vol%.

The low-temperature sintering in the step b) is a reducing atmosphere normal-pressure sintering, the sintering temperature is 400-800 ℃, the sintering temperature is optimized according to the softening temperature of the glass powder, the heat preservation time is 5-30 minutes, preferably 10-15 minutes, and the sintering atmosphere is nitrogen or a nitrogen/hydrogen mixed gas, preferably a nitrogen/hydrogen mixed gas. Further preferably, the sintering temperature is 650-700 ℃, the heat preservation time is 5-10 minutes, and the sintering atmosphere is nitrogen or nitrogen/hydrogen mixed gas.

The ceramic-glass composite structure fluorescent color wheel can realize high-brightness red, green and blue three-primary-color luminescence under the excitation of blue laser, and the color rendering index and the color gamut of obtained white light are improved.

Compared with the prior art, the invention has the following advantages:

according to the ceramic-glass composite structure fluorescent color wheel obtained by the invention, the continuous phase green luminous fluorescent ceramic structure is used as the matrix, so that the heat dissipation performance of the fluorescent color wheel can be effectively improved; the red luminescent fluorescent glass structure distributed in the ceramic substrate can provide luminescence in a red light wave band, and can be dispersed in the ceramic substrate on the premise of ensuring the luminescent performance of the red nitride fluorescent powder, so that the ceramic-glass composite structure is very suitable for a laser display light source. Under the excitation of a blue laser light source, the continuous phase high-heat-conductivity fluorescent ceramic can generate green luminescence, the excellent heat dissipation performance of the fluorescent color wheel is ensured, and the red fluorescent glass distributed in the air holes can provide luminescence of a red light wave band. The fluorescent color wheel with the glass-ceramic composite structure is excited by blue laser, so that high-brightness red, green and blue three-primary-color luminescence can be realized, and the application requirements of laser display on a wide-color-gamut and high-brightness light source are met.

Drawings

Fig. 1 is a schematic structural view of a ceramic-glass composite structure fluorescent color wheel in the invention, wherein in fig. 1, 1 is a porous green luminescent fluorescent ceramic substrate, 2 is a glass substrate, 3 is red luminescent fluorescent powder, and 4 is an internal pore;

FIG. 2 is a microstructure of a porous green-emitting fluorescent ceramic substrate according to example 1 of the present invention;

FIG. 3 is a light emission spectrum of a laser white light source in example 1 of the present invention;

fig. 4 is a light emission spectrum of a laser white light source in example 2 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The fluorescent ceramic substrate in the ceramic-glass composite structure fluorescent color wheel provided by the invention is YAGG: Ce (Y)_{3- x}Ce_xAl_5-yGa_yO₁₂，0<x≤0.5，0<y<5) Or LuAG: Ce (Lu)_3-xCe_xAl₅O₁₂，0<x is less than or equal to 0.5) single-phase structure or corresponding fluorescent powder and Al₂O₃The composite structure is formed by preferentially selecting fluorescent powder and Al₂O₃Mixing to form a complex phase structure, wherein the mass percent of the fluorescent powder is between 20 and 40 percent; the red luminous fluorescent glass in the ceramic-glass composite structure fluorescent color wheel is CaAlSiN₃:Eu(Ca_1-xEu_xAlSiN₃，0<x is less than or equal to 0.5) mixed phase of fluorescent powder and glass powder, wherein the mass percent of the fluorescent powder is between 40 and 60 percent. Green and red luminescent phosphor and Al₂O₃The powder and glass powder raw materials can be prepared by self or can be products purchased from commercial sources, wherein the glass powder raw materials are preferably low-melting-point glass powder.

The invention also provides a preparation method of the transparent complex phase fluorescent ceramic, which comprises the following steps:

a) the green luminescent phosphor YAGG is Ce or LuAG is Ce and Al₂O₃Mixing the powder, performing dry pressing to obtain a ceramic blank, and sintering the ceramic blank at a high temperature to obtain a porous green luminescent fluorescent ceramic matrix; phosphor and Al₂O₃The powder can be mixed by a mortar or an alumina ball milling tank and ball milled and mixed by alumina balls; the dry pressing pressure of the mixed powder is 10-40 Mpa, and the pressure maintaining time is 10-60 seconds; the sintering of the ceramic blank is a reducing atmosphere normal pressure sintering, the sintering temperature is 1200-1600 ℃, the heat preservation time is 1-5 hours, and the sintering atmosphere is nitrogen or nitrogen/hydrogen mixed gas.

b) Mixing red luminescent fluorescent powder and glass powder in absolute ethyl alcohol through ball milling to obtain fluorescent glass slurry, then putting the fluorescent ceramic substrate into the fluorescent glass slurry for soaking, adsorbing the fluorescent glass slurry by utilizing the adsorption characteristic of porous ceramic, and sintering the fluorescent ceramic substrate adsorbed with the red luminescent fluorescent powder and the glass powder at low temperature after the absolute ethyl alcohol is completely volatilized to obtain the fluorescent color wheel with a ceramic-glass composite structure; the red luminescent fluorescent powder and the glass powder are subjected to ball milling and mixing in absolute ethyl alcohol by preferably selecting a silicon nitride ball milling tank and a grinding ball, wherein the ball milling time is 1-10 hours; the solid content of the fluorescent glass slurry is 5-50 vol%; and low-temperature sintering selects a reducing atmosphere to sinter at normal pressure, the sintering temperature is 400-800 ℃, the sintering temperature is optimized according to the softening temperature of the glass powder, the heat preservation time is 5-30 minutes, and the sintering atmosphere is nitrogen or nitrogen/hydrogen mixed gas.

To further illustrate the technical solutions of the present invention, the following preferred embodiments of the present invention are described with reference to examples, but it should be understood that the descriptions are only for further illustrating the features and advantages of the present invention and are not to be construed as limiting the claims of the present invention.

Example 1

Weighing 2g of YAGG to Ce green luminescent phosphor (Y)_2.9Ce_0.1Al_4.0Ga_1.0O₁₂Lanboguang, Suzhou CityElectric science and technology limited) and 8gAl₂O₃Uniformly mixing the powder in an agate mortar; weighing 5g of mixed powder raw materials, pressing the mixed powder raw materials on a tablet press to form a wafer ceramic blank body with the diameter of 15 mm, wherein the pressure of the tablet press is 15Mpa, and the pressure maintaining time is 30 s; and calcining the ceramic blank in a box-type atmosphere furnace (the sintering atmosphere is nitrogen) at 1400 ℃ for 3 hours to obtain the porous green luminescent fluorescent ceramic matrix.

Weighing 4g of CaAlSiN₃Eu Red emitting phosphor (Ca)_0.9Eu_0.1AlSiN₃Suzhou Lanbo photoelectric technology Co., Ltd.), 6gZnO-B₂O₃-BaO-Al₂O₃Putting the glass powder and 15g of absolute ethyl alcohol into a silicon nitride ball milling tank for ball milling for 5 hours to obtain fluorescent glass slurry; and (3) putting the porous green luminous fluorescent ceramic substrate into the fluorescent glass slurry, soaking for 10 hours, taking out, and then putting into a tubular atmosphere furnace (the sintering atmosphere is nitrogen) to calcine for 10 minutes at 650 ℃ to obtain the final ceramic-glass composite structure fluorescent color wheel.

The microstructure of the porous green luminescent fluorescent ceramic matrix in example 1 of the invention is shown in fig. 2, and a dense structure of glass distributed in the ceramic matrix can be seen; the light emission spectrum of the laser white light source in the embodiment 1 of the invention is shown in fig. 3, and it can be seen that the red light and green light components in the white light obtained by the ceramic-glass composite structure are significantly improved, thereby improving the color rendering index and color gamut of the obtained white light.

Example 2

Weighing 3g of LuAG: Ce green luminescent phosphor (Lu)_2.9Ce_0.1Al₅O₁₂Suzhou Lanbo opto-electronic technology Co., Ltd.) and 7g Al₂O₃Uniformly mixing the powder in an agate mortar; weighing 5g of mixed powder raw materials, pressing the mixed powder raw materials on a tablet press to form a wafer ceramic blank body with the diameter of 15 mm, wherein the pressure of the tablet press is 10Mpa, and the pressure maintaining time is 10 s; and calcining the ceramic blank in a box-type atmosphere furnace (the sintering atmosphere is nitrogen) at 1300 ℃ for 3 hours to obtain the porous green luminescent fluorescent ceramic matrix.

Weighing 5g of CaAlSiN₃Eu Red emitting phosphor (Ca)_0.9Eu_0.1AlSiN₃Suzhou Lanbo opto-electronic technology Co., Ltd.), 5gK₂O-Na₂O-Al₂O₃-SiO₂Putting the glass powder and 20g of absolute ethyl alcohol into a silicon nitride ball milling tank for ball milling for 5 hours to obtain fluorescent glass slurry; and (3) putting the porous green luminous fluorescent ceramic substrate into the fluorescent glass slurry, soaking for 10 hours, taking out, and then putting into a tubular atmosphere furnace (the sintering atmosphere is nitrogen) to calcine for 5 minutes at 700 ℃ to obtain the final ceramic-glass composite structure fluorescent color wheel. The emission spectrum of the laser white light source in the embodiment 2 of the invention is shown in fig. 4, and it can be seen that the green light component in the white light obtained by the ceramic-glass composite structure is not as high as that in the embodiment 1, but the red light component is higher, and the color rendering index and the color gamut of the white light are improved as a whole.

The color rendering index CRI and the lumen efficiency (lm/W) of the ceramic-glass composite structure fluorescent color wheel prepared in the examples 1-2 are shown in Table 1.

TABLE 1

Examples	Color rendering index CRI	Lumen efficiency (lm/W)
			1	91	213
2	93	197

As can be seen from the data in Table 1, the ceramic-glass composite structure fluorescent color wheel provided by the invention can remarkably improve the color rendering index of the obtained white light to more than 90, and remarkably improve the lumen efficiency to 213lm/W at most. Therefore, the ceramic-glass composite structure fluorescent color wheel provided by the invention is very suitable for laser display light sources, and meets the application requirements of laser display on light sources with wide color gamut, high color rendering index and high brightness.