WO2018170975A1 - High-power fluorescent glass ceramic for illumination and display, preparation method therefor, and application thereof - Google Patents

Abstract

A high-power fluorescent glass ceramic for illumination and display. The fluorescent glass ceramic has a composition of (1-x)A:xB, wherein x is the percentage of B by weight, and x ranges from 1 to 40%; A is glass matrix with a composition of aSiO2-bA2O-cZnO-dMO, wherein a, b, c, and d are all molar percentages, a + b + c + d = 100, A in A2O represents an alkali metal, M in MO represents alkaline-earth metal; and B is a YAG:Ce3+ phosphor. In the fluorescent glass ceramic, the glass matrix has a low remelting temperature and easily available raw materials with low costs, and is green and pollution-free. Combined with the YAG:Ce3+ phosphor, the glass matrix features high light conversion efficiency and excellent heat aging resistance.

Description

Fluorescent glass ceramic for high power illumination and display and preparation method and application thereof Technical field

The invention belongs to the field of high-power illumination and display technology, and more particularly to a high-power illumination and display fluorescent glass ceramic and a preparation method and application thereof.

Background technique

With the improvement of blue LED light efficiency and blue LD as a new excitation light source, high-power illumination and display have important application prospects in indoor and outdoor lighting, theater and home projectors, and automotive headlights. However, the packaging material used in conventional high-power illumination and display is silica gel. Due to its low thermal conductivity and aging characteristics, the long-term use reduces the light efficiency of the illumination and display devices, and the light color drifts. In order to solve this technical problem, it is necessary to develop a novel all-inorganic light conversion material having high thermal conductivity. There are three main types that can meet this requirement at present: single crystal, transparent ceramic and fluorescent glass ceramic. Although single crystal and transparent ceramic have high thermal conductivity and excellent heat aging resistance, the preparation process is complicated, the cost is high, the repeatability is poor, and it is not suitable for mass production. These factors limit the use of all-inorganic light-converting materials in high-power illumination and display.

Fluorescent glass ceramic is a kind of all-inorganic light-converting material which is prepared by mixing phosphor and mother glass powder. It has excellent luminescent properties of phosphor and high thermal conductivity and heat aging resistance of glass. Compared with the conventional fluorescent paste, the thermal conductivity of the all-inorganic fluorescent conversion material is greatly improved and the luminescent property is well maintained. In addition, the fluorescent glass ceramics have a simple synthesis process and strong plasticity, and are expected to replace the traditional "silica gel + phosphor" mode. The fluorescent glass ceramic has both the function of a conventional phosphor and the function of a packaging material, and can be applied to a modular high-power white light illumination and display device.

Summary of the invention

The object of the present invention is to provide a high-power illumination and display fluorescent glass ceramic according to the deficiencies in the prior art.

The invention also provides a method for preparing the above-mentioned high-power illumination and display fluorescent glass ceramic.

The invention also provides the use of the above fluorescent glass ceramic in preparing a modular high power white light illumination and display device.

The object of the invention is achieved by the following technical solutions:

The invention provides a high-power illumination and display fluorescent glass ceramic, the composition of the fluorescent glass ceramic is: (1-x) A: xB, wherein x is the weight percentage of B, and the value of x ranges from 1 ～40%; A is a glass matrix, the composition is: aSiO ₂ -bA ₂ O-cZnO-dMO, a, b, c, d are all mole percentages, a+b+c+d=100, A ₂ O in A Representing an alkali metal, A ₂ O is an oxide or carbonate of an alkali metal, M in the MO represents an alkaline earth metal, MO is an oxide or carbonate of an alkaline earth metal, and B is a YAG:Ce ³⁺ phosphor.

Preferably, a:b:c:d=(40-60):(5-15):(10-30):(5-25).

Preferably, a: b: c: d = (52-55): (7-10): (18-23): (10-22).

Preferably, A is Li, Na or K; M is Ca, Ba or Sr.

The invention simultaneously provides the preparation method of the high-power illumination and display fluorescent glass ceramic, comprising the following steps:

S1. Mixing the constituent materials of the glass matrix A according to the molar percentage, melting at a high temperature, cooling to obtain a glass precursor, and pulverizing;

S2. The pulverized glass precursor in S1 is mixed with YAG:Ce ³⁺ phosphor according to the weight percentage, and pressed;

S3. Sintering the pressed mixture in S2, and polishing to obtain the high-power illumination and display fluorescent glass ceramic.

Preferably, the high temperature melting temperature in the step S1 is 1300 ° C to 1500 ° C, and the high temperature melting time is 0.5 to 2 h.

Preferably, the pressing time in step S2 is 10 to 30 minutes, and the pressing pressure is 10 to 30 MPa.

Preferably, the temperature of sintering in step S3 is 600 to 750 °C.

The invention simultaneously protects the use of the high-power illumination and display fluorescent glass ceramics in the preparation of high-power white light illumination and display materials.

Further, the high power illumination and display fluorescent glass ceramic of the present invention is excited under a high power semiconductor light source to produce high brightness white light.

The fluorescent glass ceramic provided by the invention is prepared into a high-power white light device, and the luminous efficacy thereof can reach 100 lm/W or more.

Compared with the prior art, the present invention has the following advantages and benefits:

Compared with the conventional packaged white LED and white LD, the glass mother of the present invention has a lower body temperature melting temperature, and better maintains the YAG:Ce ³⁺ luminescence when mixed with YAG:Ce ³⁺ remelting sintering. Efficiency, and the glass matrix has almost no absorption of blue light; in addition, the glass matrix itself has a high thermal conductivity, which can effectively dissipate the heat generated by the semiconductor excitation source (blue LED and blue LD); compared to conventional silica materials, Fluorescent glass ceramics excel in heat resistance, and there is substantially no transmission loss for long-term aging. At the same time, the fluorescent glass ceramic is simple in preparation process, low in cost, non-toxic and non-polluting, and mechanically and physically and chemically stable.

DRAWINGS

Figure 1 is a photograph of a glass substrate (left) and a YAG:Ce ³⁺ -PiG sample (right) in Example 1;

2 is an SEM spectrum of the matrix glass and YAG:Ce ³⁺ -PiG in Example 1;

Figure 3 is an XRD pattern of the glass precursor powder, YAG:Ce ³⁺ -PiG powder, YAG:Ce ³⁺ powder of Example 2;

4 is an application of YAG:Ce ³⁺ -PiG fluorescent glass ceramic in Example 3 in a high power white LED;

5 is an application of YAG:Ce ³⁺ -PiG fluorescent glass ceramics in Example 5 in a high power white light LD;

6 is a graph showing the lumen change with the driving current of the laser illumination device based on YAG:Ce ³⁺ -PiG in Example 6;

7 is an emission spectrum and an excitation spectrum of YAG:Ce ³⁺ -PiG fluorescent glass ceramics and YAG:Ce ³⁺ phosphors in Example 7;

detailed description

The invention is further illustrated by the following examples and the accompanying drawings, but the examples are not intended to limit the invention. Unless otherwise indicated, the reagents, methods, and devices employed in the present invention are routine reagents, methods, and devices in the art.

Unless otherwise stated, the reagents and materials used in the present invention are commercially available.

Example 1:

Synthesis of Glass Matrix 55SiO ₂ -10A ₂ O-20ZnO-15MO and Preparation of YAG:Ce ³⁺ -PiG Fluorescent Glass Ceramics

Table 1: Raw material composition of the glass precursor of Example 1

raw material	SiO 2	Na 2 CO 3	ZnO	CaCO 3
Quality (g)	33.046	15.898	16.282	10.009

Pure silica (SiO ₂ ), sodium carbonate (Na ₂ CO ₃ ), zinc oxide (ZnO), and calcium carbonate (CaCO ₃ ) were accurately weighed according to Table 1. The accurately weighed raw materials are ground in a ball mill for 6-8 hours, poured into an alumina crucible, and then melted in a 1350 ° C box furnace for 1 h, and the molten glass liquid is poured into distilled water to be cooled, dried and ground to a powder. According to the phosphor YAG:Ce ³⁺ (commercially available, the composition is Y ₃ Al ₅ O ₁₂ :Ce ³⁺ ) and the glass powder mass fraction of 5:95, after accurate weighing, it is ground in an agate mortar for 0.5 h. The rubber molds of different sizes are selected, and the mixed powder is pressed by a cold isostatic pressing tableting machine (with a pressing condition of 20 MPa for 30 minutes), and then held in a 700 ° C box furnace for 0.5 h to obtain YAG:Ce. ³⁺ -PiG fluorescent glass ceramic. The YAG:Ce ³⁺ -PiG fluorescent glass ceramic sheets of different thicknesses can be obtained by cutting and polishing the synthesized YAG:Ce ³⁺ -PiG ceramics. The glass substrate obtained by this method and a 5% YAG:Ce ³⁺ -PiG physical photograph are shown in Fig. 1. Its distribution in the glass matrix is shown in Figure 2. a, c, e, g are SEM photographs of the glass matrix at different magnifications, b, d, f, h are YAG: Ce ^{3+ -} PiG are different The SEM photograph at magnification shows that the phosphor is uniformly dispersed in the glass matrix.

Example 2: Synthesis of Glass Matrix 55SiO ₂ -8A ₂ O-20ZnO-22MO and Preparation of YAG:Ce ³⁺ -PiG Fluorescent Glass Ceramics

Table 2 Example 2 raw material composition of the glass matrix

raw material	SiO 2	Na 2 CO 3	ZnO	CaO
Quality (g)	33.046	8.479	16.282	12.34

Pure silica (SiO ₂ ), sodium carbonate (Na ₂ CO ₃ ), zinc oxide (ZnO), and calcium oxide (CaO) were accurately weighed according to Table 2. The accurately weighed raw materials are ground in a ball mill for 10 to 12 hours, poured into an alumina crucible, and then melted in a box furnace at 1400 ° C for 1.5 h. The molten glass liquid is poured into distilled water to be cooled, dried and ground into powder. . According to the phosphor and glass powder mass fraction of 7:93, after accurate weighing, grind in an agate mortar for 0.5h, select different size rubber molds, and press the mixed powder through cold isostatic pressing tablet press (The pressing condition was 30 minutes at 10 MPa), and the YAG:Ce ³⁺ -PiG fluorescent glass ceramic was obtained by holding in a box furnace at 720 ° C for 0.5 h. The synthesized YAG:Ce ³⁺ -PiG ceramics are cut and polished to obtain PiG fluorescent glass ceramic sheets of different thicknesses. The 7wt% YAG:Ce ³⁺ -PiG was ground into a powder, and the XRD was tested as shown in Fig. 3. Compared with the XRD patterns of the matrix glass and the YAG:Ce ³⁺ phosphor, it was found that in the process of preparing YAG:Ce ³⁺ -PiG The crystallization of the glass did not occur, and the crystal in the fluorescent glass ceramic was YAG:Ce ³⁺ phosphor.

Example 3: Synthesis of glass matrix 55SiO ₂ -10A ₂ O-23ZnO-12MO and preparation of YAG:Ce ³⁺ -PiG fluorescent glass ceramic

Table 3 Example 3 raw material composition of the glass matrix

raw material	SiO 2	Li 2 CO 3	ZnO	CaCO 3
Quality (g)	33.046	7.389	18.724	10.009

Pure silica (SiO ₂ ), lithium carbonate (Li ₂ CO ₃ ), zinc oxide (ZnO), and calcium carbonate (CaCO ₃ ) were accurately weighed according to Table 3. The accurately weighed raw materials are ground in a ball mill for 6-8 hours, poured into an alumina crucible, and then melted in a 1350 ° C box furnace for 1.5 h. The molten glass liquid is poured into distilled water to be cooled, dried and ground into a powder. . According to the phosphor and glass powder mass fraction of 6:94, after accurate weighing, grind in an agate mortar for 0.5h, select different size rubber molds, and press the mixed powder through cold isostatic pressing tablet press (The pressing condition was 10 minutes at 30 MPa), and the YAG:Ce ³⁺ -PiG fluorescent glass ceramic was obtained by holding in a box furnace at 680 ° C for 0.5 h. The YAG:Ce ³⁺ -PiG fluorescent glass ceramic sheets of different thicknesses can be obtained by cutting and polishing the synthesized YAG:Ce ³⁺ -PiG ceramics. A white LED device is prepared by combining YAG:Ce ³⁺ -PiG fluorescent glass ceramic piece and blue light COB chip (12W), and the illuminating photograph, electroluminescence spectrum and color coordinate are shown in Fig. 4, wherein Fig. 4a is the original part of the device. 4b is a illuminating photograph, 4c is an electro-spectral spectrum, 4d is a color coordinate, and the high-power white light device has a luminous efficacy of up to 100 lm/W.

Example 4: Synthesis of Glass Matrix 52SiO ₂ -10A ₂ O-22ZnO-16MO and Preparation of YAG:Ce ³⁺ -PiG Fluorescent Glass Ceramics

Table 4 Example 4 raw material composition of the glass matrix

raw material	SiO 2	K 2 O	ZnO	CaO
Quality (g)	31.244	11.30	17.910	8.97

Pure silica (SiO ₂ ), potassium oxide (K ₂ O), zinc oxide (ZnO), and calcium oxide (CaO) were accurately weighed according to Table 4. The accurately weighed raw materials are ground in a ball mill for 16 to 48 hours, poured into an alumina crucible, and then melted in a 1450 ° C box furnace for 0.5 h, and the molten glass liquid is poured into distilled water to be cooled, dried and ground into a powder. . According to the phosphor and glass powder mass fraction of 6:94, after accurate weighing, grind in an agate mortar for 0.5h, select different size rubber molds, and press the mixed powder through cold isostatic pressing tablet press (The pressing condition was 20 minutes at 25 MPa), and the YAG:Ce ³⁺ -PiG fluorescent glass ceramic was obtained by holding in a box furnace at 680 ° C for 0.5 h. The YAG:Ce ³⁺ -PiG fluorescent glass ceramic sheets of different thicknesses can be obtained by cutting and polishing the synthesized YAG:Ce ³⁺ -PiG ceramics.

Example 5: ₂ O-20ZnO-10MO glass matrix synthesis and YAG 53SiO ₂ -7A: Preparation of Ce ³⁺ -PiG fluorescent glass ceramic

Table 5 Example 5 raw material composition of the glass matrix

raw material	SiO 2	Na 2 CO 3	ZnO	BaCO 3
Quality (g)	31.845	7.419	16.282	19.734

Pure silica (SiO ₂ ), sodium carbonate (Na ₂ CO ₃ ), zinc oxide (ZnO), and barium carbonate (BaCO ₃ ) were analyzed by exact weighing according to Table 5. The accurately weighed raw materials were ground in a ball mill for 24 to 48 hours, poured into an alumina crucible, and then melted in a 1500 ° C box furnace for 1 h, and the molten glass liquid was poured into distilled water to be cooled, dried and ground to a powder. According to the phosphor and glass powder mass fraction of 15:85, after accurate weighing, grind in an agate mortar for 0.5h, select different sizes of rubber molds, and press the mixed powder through cold isostatic pressing tablet press (The pressing condition was 30 minutes at 30 MPa), and the YAG:Ce ³⁺ -PiG fluorescent glass ceramic was obtained by holding in a box furnace at 750 ° C for 1 h. The YAG:Ce ³⁺ -PiG fluorescent glass ceramic sheets of different thicknesses can be obtained by cutting and polishing the synthesized YAG:Ce ³⁺ -PiG ceramics. The fluorescent glass ceramic sheet is combined with the laser LD to prepare white light LD devices of different light colors, and one of the white light LD devices has an electroluminescence spectrum as shown in FIG. 5.

Example 6: Synthesis of glass precursor 54SiO ₂ -8A ₂ O-18ZnO-20MO and preparation of YAG:Ce ³⁺ --PiG fluorescent glass ceramic

Table 6 Example 6 raw material composition of the glass matrix

raw material	SiO 2	Na 2 O	ZnO	CaCO 3
Quality (g)	32.446	16.585	14.654	20.017

Pure silica (SiO ₂ ), sodium carbonate (Na ₂ CO ₃ ), zinc oxide (ZnO), and calcium carbonate (CaCO ₃ ) were accurately weighed according to Table 6. The accurately weighed raw materials are ground in a ball mill for 6 to 18 hours, poured into an alumina crucible, and then melted in a 1450 ° C box furnace for 0.5 h. The molten glass liquid is poured into distilled water to be cooled, dried and ground into a powder. . According to the phosphor and glass powder mass fraction of 20:80, after accurate weighing, grind in an agate mortar for 0.5h, select different sizes of rubber molds, and then mix the mixed powder by cold isostatic pressing tablet press (The pressing condition was 30 minutes at 25 MPa), and the YAG:Ce ³⁺ -PiG fluorescent glass ceramic was obtained by keeping it in a box furnace at 600 ° C for 0.5 h. The YAG:Ce ³⁺ -PiG fluorescent glass ceramic sheets of different thicknesses can be obtained by cutting and polishing the synthesized YAG:Ce ³⁺ -PiG ceramics. The obtained YAG:Ce ³⁺ -PiG fluorescent glass ceramic sheet performs well under different currents (alternating current) driven by the blue laser. As shown in Fig. 6, as the driving current of the laser increases, the lumen of the device gradually increases, and at 1.4A. When the time is optimal.

Example 7: Synthesis of glass precursor 54SiO ₂ -8A ₂ O-18ZnO-20MO and preparation of YAG:Ce ³⁺ -PiG fluorescent glass ceramic

Table 7 Example 7 raw material composition of the glass matrix

raw material	SiO 2	Na 2 CO 3	ZnO	SrO
Quality (g)	3.2446	1.6585	1.4654	20.72

Pure silica (SiO ₂ ), sodium carbonate (Na ₂ CO ₃ ), zinc oxide (ZnO), and strontium oxide (SrO) were analyzed by exact weighing according to Table 7. The accurately weighed raw materials are ground in a ball mill for 12 to 36 hours, poured into an alumina crucible, and then melted in a box furnace at 1300 ° C for 2 hours, and the molten glass liquid is poured into distilled water to be cooled, dried and ground to a powder. According to the phosphor and glass powder mass fraction of 40:60, after accurate weighing, grind in an agate mortar for 0.5h, select different sizes of rubber molds, and press the mixed powder through cold isostatic pressing tablet press (The pressing condition was 20 minutes at 20 MPa), and the YAG:Ce ³⁺ -PiG fluorescent glass ceramic was obtained by holding in a box furnace at 710 ° C for 1 h. The YAG:Ce ³⁺ -PiG fluorescent glass ceramic sheets of different thicknesses can be obtained by cutting and polishing the synthesized YAG:Ce ³⁺ -PiG ceramics. The excitation and emission spectra of the prepared YAG:Ce ³⁺ -PiG fluorescent glass ceramic sheets are shown in Fig. 7.

Claims (10)

1. A high-power illumination and display fluorescent glass ceramic, characterized in that the composition of the fluorescent glass ceramic is: (1-x) A: xB, wherein x is a weight percentage of B, and x has a value range of 1 ～40%; A is a glass matrix, the composition is: aSiO ₂ -bA ₂ O-cZnO-dMO, a, b, c, d are all mole percentages, a+b+c+d=100, A ₂ O in A Representing an alkali metal, A ₂ O is an oxide or carbonate of an alkali metal, M in the MO represents an alkaline earth metal, MO is an oxide or carbonate of an alkaline earth metal, and B is a YAG:Ce ³⁺ phosphor.
2. The high-power illumination and display fluorescent glass ceramic according to claim 1, wherein a:b:c:d=(40-60):(5-15):(10-30):(5- 25).
3. A high-power illumination and display fluorescent glass ceramic according to claim 2, wherein a:b:c:d=(52-55):(7-10):(18-23):(10- twenty two).
4. The fluorescent glass ceramic for high power illumination and display according to claim 1, wherein A is Li, Na or K; and M is Ca, Ba or Sr.
5. A method for preparing a high-power illumination and display fluorescent glass ceramic according to claim 1, comprising the steps of:

   S1. Mixing the constituent materials of the glass matrix A according to the molar percentage, melting at a high temperature, cooling to obtain a glass precursor, and pulverizing;

   S2. The pulverized glass precursor in S1 is mixed with YAG:Ce ³⁺ phosphor according to the weight percentage, and pressed;

   S3. Sintering the pressed mixture in S2, and polishing to obtain the high-power illumination and display fluorescent glass ceramic.
6. The preparation method according to claim 5, wherein the high temperature melting temperature in the step S1 is 1300 ° C to 1500 ° C, and the high temperature melting time is 0.5 to 2 h.
7. The preparation method according to claim 5, wherein the pressing time in the step S2 is 10 to 30 minutes, and the pressing pressure is 10 to 30 MPa.
8. The production method according to claim 5, wherein the temperature of sintering in the step S3 is 600 to 750 °C.
9. The use of the high power illumination and display fluorescent glass ceramic of any of claims 1 to 5 for the preparation of high power white light illumination and display materials.
10. The use of claim 9 wherein said high power illumination and display fluorescent glass ceramic are excited to produce high brightness white light under a high power semiconductor light source.

Images