A high-efficiency composite fluorescent glass material and preparation method thereof

Abstract

The present invention discloses a high-efficiency composite fluorescent glass material and its preparation method, which specifically belongs to the technical field of luminescent glass. The composite fluorescent glass material comprises phosphate matrix glass powder and YAG:Ce 3+ Yellow phosphor. The specific preparation method is: phosphate matrix glass powder and YAG: Ce 3+ The phosphor powder is ground and mixed uniformly, then melted to obtain a glass liquid, which is then cast and annealed to obtain a composite fluorescent glass material. The composite fluorescent glass material prepared by the present invention has high transparency, a low melting point, is safe and environmentally friendly, emits uniform light, is easy to process, has high luminous efficiency, good thermal conductivity, and good resistance to laser radiation. When encapsulated on an LD chip, it produces white light with ultra-high luminous efficiency, is conducive to promotion and application, and has broad market prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of luminescent glass, and in particular relates to a high-efficiency composite fluorescent glass material and a preparation method thereof. Background Art

[0002] Solid-state lighting (SSL) technology has undergone significant development and has become increasingly mature in the lighting and display fields. However, a series of drawbacks of traditional light-emitting diodes (LEDs), such as the "efficiency drop" caused by Auger recombination, have become increasingly prominent, severely limiting their application in high-power applications. Laser light sources based on laser diodes (LDs) can maintain high luminous efficiency under high-power excitation, as well as have advantages such as high brightness, small size, and stable output, and have attracted widespread attention from researchers. Compared with the use of pure laser mixing to output white light, the laser phosphor conversion method, which uses phosphors to generate white light output under blue light or near-ultraviolet LD excitation, has no speckle noise, is more cost-effective, and has a broader application space and stronger industrialization potential. Y3Al5O 12 ∶Ce 3+ (YAG∶Ce 3+ ) phosphor can be effectively excited by 450nm blue light, producing a wide luminescence range covering 300-700nm and exhibiting excellent luminescence tunability. This makes it stand out from other phosphors capable of white light emission, becoming one of the most intensively researched and widely used. However, because the power density of LDs is much greater than that of LEDs, the heat generated by excited phosphors increases exponentially. Conventional encapsulation materials, such as organic resins and silicones, have low thermal conductivity and poor heat resistance, resulting in low luminous efficiency and short lifespans for devices made from them.

[0003] Phosphorescent glass (PIG), a novel inorganic phosphor conversion material, utilizes the viscous flow properties of glass to composite phosphors into a glass matrix. This method retains the phosphor's high luminous efficiency while also offering the advantages of glass's excellent thermal conductivity and stable performance. Compared with phosphor single crystals (SCPs) and phosphor ceramics (TCPs), PIGs have generated significant attention due to their more flexible and tunable luminous properties, simpler preparation process, and lower overall cost. For example, Professor Wang Jing et al. composited silicate glass with YAG phosphor, achieving a white light output of 110 lm and 85 lm / W under 445nm blue laser light excitation. Qiu Jianrong's research group used 3D printing technology to produce an all-inorganic YAG:CePiSG with an internal quantum efficiency (IQE) exceeding 90.0%. Xiang Weidong et al. co-fired YAG with an optimized borosilicate glass composition at low temperature, producing a PIG that can withstand 3.15 W / mm 2It can be seen that changes in the glass matrix have a significant impact on the performance of fluorescent glass. However, in the existing technology, most research on fluorescent glass focuses on silicate glass with high thermal and chemical stability, while research on phosphate glass is rare.

[0004] Therefore, it is a technical problem that those skilled in the art urgently need to solve to develop a high-efficiency composite fluorescent glass material with phosphate as the glass matrix, a low transition temperature, and stable thermal properties. Summary of the Invention

[0005] In order to solve the above problems in the prior art, the present invention provides a high-efficiency composite fluorescent glass material and a preparation method thereof.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a high-efficiency composite fluorescent glass material, which comprises a phosphate matrix glass powder and YAG:Ce 3+ Yellow phosphor.

[0008] Beneficial effects: The present invention uses low-melting-point phosphate as the main glass raw material, which has a lower glass transition temperature, reduces the glass melting temperature, reduces the corrosion effect on the phosphor during the melting process, and is beneficial to improving the luminescent performance of the fluorescent material.

[0009] Furthermore, the phosphate matrix glass powder and YAG:Ce 3+ The mass ratio of the yellow phosphor is (85-100):(0-15).

[0010] Beneficial effect: The present invention combines the melting temperature and luminescence performance of the composite fluorescent glass material, and adopts phosphate matrix glass powder and YAG:Ce 3+ The mass ratio of yellow phosphor is (85-100): (0-15), which reduces the YAG:Ce ratio in the melting process. 3+ The possibility of yellow phosphor being corroded ensures that the luminous performance of the material is at a better level.

[0011] Furthermore, the phosphate matrix glass powder is a halide-modified phosphate glass powder; the raw material components of the phosphate matrix glass powder include, by molar percentage, SnO: 20%; GeO2: 10%; ZnO: 10-25%; ZnCl2: 5-20%; and NH4H2PO4: 40%.

[0012] Beneficial effect: The present invention uses ZnCl2 to partially replace ZnO, which can improve the transmittance of the matrix glass while ensuring that the thermal properties of the glass are not affected, which is beneficial to improving the luminescent properties of the fluorescent material.

[0013] Furthermore, the method for preparing the phosphate-based glass powder comprises the following steps:

[0014] SnO, GeO2, ZnO, ZnCl2 and NH4H2PO4 are ground separately and then mixed evenly, and then preheated and melted to obtain glass liquid, and then the glass liquid is cast, annealed, ground and sieved to obtain the phosphate matrix glass powder.

[0015] Beneficial effects: The present invention adopts a high-temperature melting and cooling method to prepare phosphate-based glass powder, which has a simple process, is conducive to industrial promotion, improves production efficiency, and saves costs.

[0016] Furthermore, the grinding time is 30 minutes; and the preheating is: preheating at 400° C. for 30 minutes.

[0017] Beneficial effect: The present invention preheats the raw materials before melting to decompose NH4H2PO4, allowing the gas to escape and reducing the generation of bubbles during the glass melting process.

[0018] Furthermore, the melting is carried out by melting at a temperature of 1100° C. for 1 hour, and then homogenizing and clarifying to obtain glass liquid.

[0019] Furthermore, the pouring is: pouring the glass liquid into a mold preheated to 350°C; the annealing is: placing the poured mold into a muffle furnace heated to 300°C, keeping it warm for 2-3 hours, closing the muffle furnace, and cooling the temperature to room temperature.

[0020] Furthermore, the sieving is through a 200-mesh sieve.

[0021] The present invention also provides a method for preparing a high-efficiency composite fluorescent glass material, comprising the following steps:

[0022] The phosphate matrix glass powder and YAG:Ce 3+ The phosphor powder is ground and mixed evenly, and then melted to obtain glass liquid. The glass liquid is then cast and annealed to obtain the composite fluorescent glass material.

[0023] Beneficial effects: The present invention adopts a secondary melting method to prepare fluorescent glass, which simplifies the preparation process, shortens the production cycle, facilitates large-scale production, and is beneficial to improving production efficiency and reducing production costs.

[0024] Furthermore, the grinding is performed until the glass passes through a 400-mesh sieve; the melting is performed at 900-1010° C. for 30 minutes; the pouring is performed by pouring the glass liquid into a mold preheated to 350° C.; and the annealing is performed by placing the glass liquid in a muffle furnace heated to 300° C., keeping the temperature for 2-3 hours, closing the muffle furnace, and lowering the temperature to room temperature.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention uses phosphate as the glass matrix. The presence of phosphorus-oxygen double bonds (P=O) in phosphate makes the apex angles of the phosphorus-oxygen tetrahedron [PO4] extremely unstable, making it easy to deform into a layered structure. This enables phosphate glass to have many advantages such as low viscosity, low transition temperature and softening temperature, and is the reason why it has unlimited potential in PIG design and preparation.

[0027] The composite fluorescent glass material prepared by the present invention has high transparency, low melting point, safety and environmental protection, uniform luminescence, easy processing, high luminescence efficiency, good thermal conductivity, good resistance to laser radiation, and can be packaged on an LD chip to obtain white light with ultra-high luminescence efficiency, which is conducive to promotion and application and has broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 This is a visible light transmittance graph of the phosphate-based glass prepared in Examples 1-4 of the present invention;

[0030] Figure 2 This is a differential thermal curve of the phosphate-based glass prepared in Example 4 of the present invention;

[0031] Figure 3 XRD and YAG:Ce composite fluorescent glass prepared in Examples 5-8 of the present invention 3+ Phosphor PDF standard card comparison chart;

[0032] Figure 4 The excitation spectra of the composite fluorescent glass prepared in Examples 6-8 of the present invention in the 300-540 nm band at an emission wavelength of 560 nm, and the emission spectra in the 480-740 nm band at an excitation wavelength of 450 nm;

[0033] Figure 5 This is the color coordinate diagram of the composite fluorescent glass prepared in Examples 6-8 of the present invention. DETAILED DESCRIPTION

[0034] Various exemplary embodiments of the present invention are now described in detail. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention.

[0035] In addition, for numerical ranges in the present invention, it is understood that each intervening value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated value or intervening value in the stated range is also included in the present invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

[0036] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0037] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0038] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0039] The raw materials used in the embodiments of the present invention can be purchased commercially.

[0040] The room temperature in the embodiments of the present invention is 25±2°C.

[0041] Example 1

[0042] A method for preparing phosphate-based glass comprises the following steps:

[0043] The raw materials were weighed according to the molar percentage of 20% SnO, 10% GeO2, 25% ZnO, 5% ZnCl2 and 40% NH4H2PO4, and each raw material was ground for 30 minutes and then mixed to obtain a mixture. The mixture was then placed in a platinum crucible and preheated in a 400°C muffle furnace for 30 minutes. After the preheating, the platinum crucible was immediately transferred to a 1100°C silicon carbon rod electric furnace for melting for 1 hour. After homogenization and clarification, a uniform bubble-free glass liquid was obtained, which was then quickly poured into a brass mold preheated to 350°C to form. Finally, the cast mold was placed in a muffle furnace heated to 300°C. After keeping warm for 2 hours, the muffle furnace was closed and the temperature was lowered to room temperature to obtain phosphate matrix glass.

[0044] Example 2

[0045] A method for preparing phosphate-based glass, which differs from Example 1 only in that the molar percentages of the raw materials used in preparing the phosphate-based glass are 20% SnO, 10% GeO2, 20% ZnO, 10% ZnCl2, and 40% NH4H2PO4. The remaining steps are the same as those in Example 1.

[0046] Example 3

[0047] A method for preparing phosphate-based glass, which differs from Example 1 only in that the molar percentages of the raw materials used in preparing the phosphate-based glass are 20% SnO, 10% GeO2, 15% ZnO, 15% ZnCl2, and 40% NH4H2PO4. The remaining steps are the same as those in Example 1.

[0048] Example 4

[0049] A method for preparing phosphate-based glass, which differs from Example 1 only in that the molar percentages of the raw materials used in preparing the phosphate-based glass are 20% SnO, 10% GeO2, 10% ZnO, 20% ZnCl2, and 40% NH4H2PO4. The remaining steps are the same as those in Example 1.

[0050] The phosphate matrix glasses prepared in Examples 1-4 were cut and ground, and the glass sheets were processed and polished. The transmittance spectra of the visible light band were tested respectively. The transmittance of the visible light band is shown in the figure below. Figure 1 As shown, the test results show that the phosphate-based glasses prepared in Examples 1-3 are transparent and free of crystallization. The transmittance of the phosphate-based glass prepared in Example 1 in the visible light band is basically the same at around 68%; the transmittance of the phosphate-based glass prepared in Example 2 in the visible light band is basically the same at around 75%; and the transmittance of the phosphate-based glass prepared in Example 3 in the visible light band is basically the same at around 78%. In summary, Examples 1-3 need to be further improved to increase the transmittance so as to be suitable for the preparation and application of composite fluorescent glass materials.

[0051] The phosphate-based glass prepared in Example 4 is transparent and free of crystallization. Its transmittance in the visible light band is approximately 85%, making it suitable for the preparation and application of composite fluorescent glass materials. Furthermore, another phosphate-based glass prepared in Example 4 was ground into a fine powder using an agate mortar and subjected to differential thermal analysis. Figure 2 As shown in the test results, the melting point of the matrix glass is T g At around 346℃, it has good thermal stability ΔT(T x -T g )=130℃, a secondary heat treatment can be performed to prepare a composite fluorescent glass material.

[0052] Example 5

[0053] A method for preparing a high-efficiency composite fluorescent glass material comprises the following steps:

[0054] The phosphate-based glass prepared in Example 4 was placed in an agate mortar and ground, passed through a 200-mesh sieve to obtain a phosphate-based glass powder, which was then further ground until it passed through a 400-mesh sieve, placed in a platinum crucible, and melted in a 900° C. silicon-carbon rod electric furnace for 30 minutes. After homogenization and clarification, a uniform, bubble-free glass liquid was obtained. The glass liquid was then poured into a mold preheated to 350° C. and finally placed in a muffle furnace heated to 300° C. and kept warm for 3 hours. The muffle furnace was then closed and the temperature was cooled to room temperature to obtain a composite fluorescent glass material.

[0055] Example 6

[0056] A method for preparing a high-efficiency composite fluorescent glass material comprises the following steps:

[0057] The phosphate matrix glass prepared in Example 4 was put into an agate mortar for grinding and passed through a 200-mesh sieve to obtain phosphate matrix glass powder. Then, the phosphate matrix glass powder and phosphor YAG:Ce were weighed in a mass ratio of 95:5. 3+ , grind them respectively until they pass through a 400-mesh sieve and then mix them evenly to obtain a mixture, put them into a platinum crucible, and place them in a 900°C silicon carbon rod electric furnace for melting for 30 minutes. After homogenization and clarification, a uniform bubble-free glass liquid is obtained. The glass liquid is then poured into a mold that has been preheated to 350°C, and finally placed in a muffle furnace that has been heated to 300°C. After keeping warm for 3 hours, the muffle furnace is closed and the temperature is reduced to room temperature to obtain a composite fluorescent glass material.

[0058] Example 7

[0059] A method for preparing a high-efficiency composite fluorescent glass material, which differs from Example 6 only in that phosphate matrix glass powder and phosphor YAG:Ce are weighed in a mass ratio of 90:10.3+ , the remaining steps are the same as in Example 6.

[0060] Example 8

[0061] A method for preparing a high-efficiency composite fluorescent glass material, which differs from Example 6 only in that the phosphate matrix glass powder and the fluorescent powder YAG:Ce are weighed in a mass ratio of 85:15. 3+ , the remaining steps are the same as in Example 6.

[0062] The composite fluorescent glass material prepared in Example 5-8 was ground into fine powder using an agate mortar and subjected to XRD test. The XRD pattern was similar to that of YAG:Ce 3+ Comparison chart of phosphor standard cards Figure 3 As shown, the test results show that the fluorescent glass phosphor YAG: Ce prepared in Example 5 3+ The addition amount of 0, its XRD spectrum shows a large broad peak, which means that there is no crystallization after the secondary melting treatment, and it is suitable for the secondary melting of the composite phosphor to prepare the fluorescent glass material; the XRD characteristic peaks of the composite fluorescent glass material prepared in Examples 6-8 are similar to those of YAG: Ce 3+ The phosphor standard card is consistent when compared with the standard card, and no impurities are produced.

[0063] The composite fluorescent glass materials prepared in Examples 6-8 were cut, ground, processed, and polished, and the luminescence properties were tested. The excitation spectrum in the 300-540 nm band at an emission wavelength of 560 nm and the emission spectrum in the 480-740 nm band under 450 nm laser diode pumping were as follows: Figure 4 As shown, the results show that with the increase of YAG∶Ce 3+ With the increase of phosphor doping concentration, the spectral intensity gradually increases, indicating that the luminescence performance of the fluorescent material has been improved.

[0064] According to the emission spectrum of 380-780nm band under the excitation of 450nm blue laser light source, the color coordinate calculation results of Examples 6-8 are as follows Figure 5 As shown in the test results, the examples 6-8 can obtain excellent 560nm YAG:Ce 3+ Yellow light is emitted and a blue laser light source is mixed. In Example 6, the color coordinates are (0.244, 0.1991), which is biased towards blue light. The yellow light emission needs to be further enhanced to obtain high-efficiency white light output. The color coordinates of Example 7 are (0.3178, 0.3306), which can achieve white light output that is slightly biased towards blue-green. The color coordinates of Example 8 are (0.3326, 0.3406), which are close to the ideal white light color coordinates (0.33, 0.33), and can achieve high-efficiency white light output.

[0065] In summary, the composite fluorescent glass material prepared by the present invention has high transparency, low melting point, safety and environmental protection, uniform luminescence, easy processing, high luminescence efficiency, and good thermal conductivity and laser radiation resistance.

[0066] The above description is only a preferred specific embodiment of the present invention, and the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention within the technical scope disclosed in the present invention, and these changes should be covered by the scope of protection of the present invention.

Claims

1. A high-efficiency composite fluorescent glass material, characterized in that: The composite fluorescent glass material comprises phosphate matrix glass powder and YAG:Ce 3+ Yellow phosphor; The phosphate matrix glass powder and YAG:Ce 3+ The mass ratio of yellow phosphor is (85-100): (0-15); The phosphate matrix glass powder is a halide-modified phosphate glass powder; the raw material components of the phosphate matrix glass powder include SnO: 20% by molar percentage; GeO2: 10%; ZnO: 10%; ZnCl2: 20%; NH4H2PO4: 40%; The preparation method of the phosphate-based glass powder comprises the following steps: grinding SnO, GeO2, ZnO, ZnCl2 and NH4H2PO4 for 30 minutes respectively and then uniformly mixing them, then preheating them at 400°C for 30 minutes, melting them at 1100°C for 1 hour, homogenizing and clarifying them to obtain glass liquid, pouring the glass liquid into a mold preheated to 350°C, placing the poured mold into a muffle furnace heated to 300°C, keeping the temperature for 2-3 hours, closing the muffle furnace, cooling the temperature to room temperature, and then grinding the mixture through a 200-mesh sieve to obtain the phosphate-based glass powder; The method for preparing the high-efficiency composite fluorescent glass material comprises the following steps: mixing the phosphate matrix glass powder with YAG:Ce 3+ The phosphor powder is ground until it passes through a 400-mesh sieve and then mixed evenly. The mixture is then melted at 900-1010° C. for 30 minutes to obtain a glass liquid. The glass liquid is then poured into a mold preheated to 350° C. and placed in a muffle furnace heated to 300° C. After being kept warm for 2-3 hours, the muffle furnace is closed and the temperature is lowered to room temperature to obtain the composite fluorescent glass material.

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