A microcrystalline glass, a preparation method and application thereof

Abstract

The application belongs to the technical field of solid light-emitting materials, and discloses a kind of microcrystalline glass and its preparation method and application.The microcrystalline glass includes Ba2SiO4:Eu 2+ Single crystal phase, or Ba2SiO4:Eu 2+ And BaSiO3:Eu 2+ At least one of the double crystal phase.The microcrystalline glass of the application has excellent stability and light-emitting performance, and can be widely applied in the field of display or illumination, especially suitable for outdoor display and high-power illumination field.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid luminescent materials, and in particular relates to a microcrystalline glass and a preparation method and application thereof. Background Art

[0002] At present, solid-state lighting is widely used for its comprehensive advantages such as energy saving, environmental protection, compactness and long life. Solid-state lighting refers to the technology of using solid-state electronic components as the excitation source for lighting, represented by light-emitting diodes (LEDs) and laser diodes (LDs). Due to the limitations of the stimulated characteristics of semiconductors and lasers, it is impossible to obtain a continuous white light spectrum by relying solely on solid-state electronic components. In order to obtain a continuous white light spectrum, it is usually necessary to couple the luminescent material with the LED / LD chip to obtain a white light lighting device. For example, the white light LED (WLED) and LD lighting devices on the market are composed of a blue LED / LD chip and a yellow YAG:Ce 3+ Phosphor composition.

[0003] For high-power lighting, the heat generated by energy losses (such as photoelectric energy conversion and Stokes shift of the luminescent material) increases dramatically. Reports indicate that the cumulative heat release of high-power LED chips during operation can even exceed 200°C, and under 10W blue LD irradiation, the internal temperature of the LD device can reach 260°C within 10 minutes. Phosphors exposed to such long-term high-temperature environments will face problems such as thermal quenching and decreased luminous efficiency, inevitably leading to serious issues such as color shift and reduced luminous efficiency. Furthermore, irradiation with high-power chips inevitably accelerates the aging and yellowing of heat-resistant organic binders such as resins and silicones, and even leads to ablation. Therefore, heat dissipation has become a major bottleneck restricting the development of high-power solid-state lighting. Exploring luminescent materials with high luminous efficiency and excellent thermal stability based on existing LED / LD chip technology presents a formidable challenge.

[0004] To this end, a growing number of scientists are turning their attention to solid-state luminescent materials with excellent optical properties. These materials primarily include single crystals, ceramics, and glass. The high manufacturing costs and inability to mass-produce single crystals and ceramics significantly limit their widespread market application. Glass, on the other hand, suffers from low luminous efficiency due to its amorphous structure.

[0005] Therefore, there is an urgent need to provide a new solid luminescent material. Summary of the Invention

[0006] The present invention aims to address at least one of the technical problems existing in the aforementioned prior art. To this end, the present invention provides a glass-ceramic, its preparation method, and its application. The glass-ceramic described in the present invention exhibits excellent stability and luminescence properties and can be widely used in display and lighting applications, particularly in outdoor displays and high-power lighting.

[0007] The glass-ceramic of the present invention is a glass-ceramic containing a large amount of microcrystalline phase (belonging to phosphor crystal) and glass phase, which can be obtained by controlling the crystallization of specific component raw materials during heating. 2+ )-doped glass-ceramics combine the advantages of phosphor crystals and glass, offering high luminous efficiency, excellent thermal stability, and high transparency. They also possess a hard, dense, and uniform texture, flexible composition control, corrosion resistance, ease of processing, and low cost for large-scale production. The glass-ceramics of the present invention also possess a viscous network structure that allows for uniform dispersion of the microcrystals. Therefore, possessing these advantages, the glass-ceramics of the present invention are suitable for outdoor displays and high-power lighting applications.

[0008] A first aspect of the present invention provides a glass-ceramic.

[0009] Specifically, a microcrystalline glass includes Ba2SiO4:Eu 2+ Single crystal phase, or Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ At least one of the twin crystal phases.

[0010] Preferably, the Ba2SiO4:Eu 2+ The single crystal phase has an elongated strip-like morphology.

[0011] Preferably, the Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ The twin crystal phase has an elongated stripe-like morphology.

[0012] Preferably, the Ba2SiO4:Eu 2+ Single crystal phase, Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ The grain length of the twin crystal phase is 50-550 μm, more preferably 100-500 μm.

[0013] Preferably, the glass-ceramics can emit a strong broadband spectrum in the wavelength range of 420 to 650 nm under 365 nm light excitation, and further the main emission peak is located at 508 nm.

[0014] Preferably, the quantum efficiency of the glass-ceramics is not less than 88%, for example, 88-92%.

[0015] Preferably, after the glass-ceramics is immersed in water for 60 days, the luminous intensity decreases by no more than 3%, for example, the luminous intensity decreases by 1-3%.

[0016] A second aspect of the present invention provides a method for preparing glass-ceramics.

[0017] Specifically, a method for preparing glass-ceramics includes the following steps:

[0018] Weighing SiO2, BaO, and Eu2O3 raw materials, then mixing them, heating and melting them under a reducing atmosphere, and then cooling them to obtain the microcrystalline glass;

[0019] In the raw materials, the molar percentage of SiO2 is 40-60%, the molar percentage of BaO is 40-60%, and the molar percentage of BaO is greater than the molar percentage of SiO2;

[0020] The heating and melting temperature exceeds 1500°C.

[0021] Preferably, in the raw material, the molar percentage of Eu2O3 is 0.01-2%, more preferably 0.1-0.2%.

[0022] Preferably, in the raw materials, the molar percentage of SiO2 is 40-60%, the molar percentage of BaO is 40-60%, the molar percentage of Eu2O3 is 0.01-2%, and the molar percentage of BaO is greater than the molar percentage of SiO2.

[0023] Further preferably, in the raw materials, the molar percentage of SiO2 is 45%, the molar percentage of BaO is 54.8%, and the molar percentage of Eu2O3 is 0.2%.

[0024] Preferably, the heating and melting temperature is 1580-1650°C, more preferably 1580-1600°C.

[0025] Preferably, the heating and melting temperature is 1580-1650° C. and maintained for 0.8-6 hours, more preferably for 1-6 hours.

[0026] Preferably, the reducing atmosphere is selected from at least one of H2, CO or carbon powder.

[0027] Preferably, the mixing process is performed by grinding, for example, for 20-30 minutes.

[0028] Preferably, the cooling is natural cooling to room temperature, for example, cooling to room temperature in a muffle furnace.

[0029] Preferably, the cooling time is 8-10 hours.

[0030] A third aspect of the present invention provides an application of glass-ceramics.

[0031] A display or lighting device comprises the above-mentioned glass-ceramics.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The present invention adopts specific preparation conditions (raw material ratio and heating melting temperature) to prepare transparent fluorescent Ba2SiO4:Eu with long crystal morphology. 2+ Single crystal phase or Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ The double-crystal phase microcrystalline glass has a hard, dense and uniform texture, stable physical and chemical properties (after immersion in water for 60 days, the luminescence intensity does not drop by more than 3%), and can emit strong green light under ultraviolet light excitation (quantum efficiency is not less than 88%).

[0034] (2) The present invention economically and affordably uses SiO2, BaO and Eu2O3 as raw materials to prepare glass-ceramics, and the preparation cost is low.

[0035] (3) The present invention prepares a transparent fluorescent microcrystalline glass with adjustable structure and long crystal morphology. The crystal phase in the microcrystalline glass can be selected from Ba2SiO4:Eu 2+ Single crystal phase modulation into Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ Twin crystal phase.

[0036] (4) The microcrystalline glass of the present invention is prepared in a one-step process, which has simple process, low cost, non-toxicity and pollution-free. The microcrystalline glass material has excellent luminescence performance and can be developed as a green fluorescent solid luminescent material and applied in laser lighting. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is the XRD pattern of the glass-ceramics prepared in Example 1 of the present invention;

[0038] Figure 2 This is a digital photograph of the glass-ceramics prepared in Example 1 of the present invention;

[0039] Figure 3 This is a morphology image of the glass-ceramics prepared in Example 1 of the present invention taken under an optical microscope;

[0040] Figure 4 This is a morphology image of the glass-ceramics prepared in Example 1 of the present invention taken under a scanning electron microscope (SEM);

[0041] Figure 5 1 is a normalized excitation and emission spectrum of the glass-ceramics prepared in Example 1 of the present invention;

[0042] Figure 6 1 is a comparison of the spectral intensities of the glass-ceramics prepared in Example 1 of the present invention after 0 days and 60 days in water;

[0043] Figure 7 1 is a normalized excitation and emission spectrum of the glass-ceramics prepared in Example 2 of the present invention;

[0044] Figure 8 1 is a normalized excitation and emission spectrum of the glass-ceramics prepared in Example 3 of the present invention;

[0045] Figure 9 1 is a normalized excitation and emission spectrum of the glass-ceramics prepared in Example 4 of the present invention;

[0046] Figure 10 1 is the XRD pattern of the amorphous glass prepared in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0047] In order to make the technical solution of the present invention more clearly understood by those skilled in the art, the following examples are given for illustration. It should be noted that the following examples do not limit the scope of protection claimed by the present invention.

[0048] Unless otherwise specified, the raw materials, reagents, or devices used in the following examples can be obtained from conventional commercial sources or by existing known methods.

[0049] Figure 1 In the table, “Intensity” indicates intensity, 2θ indicates diffraction angle, “degree” indicates degree, “PDF#70-2113” indicates the standard card of Ba2SiO4, and “PDF#70-2112” indicates the standard card of BaSiO3.

[0050] Figures 5 to 9 "Intensity" here means intensity, and "Wavelength" means wavelength.

[0051] Figure 6 The “day” in means day.

[0052] Figure 10 In the figure, “Intensity” represents intensity, 2θ represents diffraction angle, and “degree” represents degree.

[0053] Example 1

[0054] A glass-ceramic comprising Ba2SiO4:Eu 2+ Single crystal phase.

[0055] A method for preparing glass-ceramics comprises the following steps:

[0056] S1. Weigh the required raw materials SiO2, BaO, and Eu2O3 according to the molar fractions of 45 mol% SiO2, 54.8 mol% BaO, and 0.2 mol% Eu2O3, mix and grind them for 30 minutes, and place the mixed and ground raw materials in a crucible;

[0057] S2. Place the crucible with the raw materials in a large crucible with a lid covered with activated carbon powder as a reducing atmosphere, keep it in a muffle furnace at 1600℃ for 1 hour to melt it, and then slowly cool it from 1600℃ to room temperature over 9 hours in the muffle furnace to obtain a block of Ba2SiO4:Eu 2+ Single crystal phase glass-ceramics.

[0058] Figure 1 is the XRD pattern of the glass-ceramics prepared in Example 1 of the present invention; Figure 2 This is a digital photograph of the glass-ceramics prepared in Example 1 of the present invention; Figure 3 This is a morphology image of the glass-ceramics prepared in Example 1 of the present invention taken under an optical microscope;

[0059] Figure 4 This is a morphology image of the glass-ceramics prepared in Example 1 of the present invention taken under a scanning electron microscope (SEM); Figure 5 1 is a normalized excitation and emission spectrum of the glass-ceramics prepared in Example 1 of the present invention; Figure 6 1 is a comparison of the spectral intensities of the glass-ceramics prepared in Example 1 of the present invention after 0 days and 60 days in water;

[0060] from Figure 1 It can be seen from the X-ray diffraction peak that Ba2SiO4:Eu has been precipitated in the prepared microcrystalline glass. 2+ Single crystal phase.

[0061] The prepared glass-ceramics still has a certain degree of transparency when the thickness is 2mm, and there are long strips of crystals visible to the naked eye embedded in the glass on the surface of the glass-ceramics (see Figure 2 ).

[0062] Under an optical microscope, it was clearly observed that a long strip-shaped glass-ceramic was successfully prepared (see Figure 3 ).

[0063] Further observation under the scanning electron microscope (SEM) revealed that the crystals were clearly strip-shaped, with a grain length of approximately 100-500 μm (see Figure 4 ).

[0064] Under the excitation of 365nm wavelength violet light, the glass-ceramics prepared in this example exhibited bright green luminescence. The normalized excitation and emission spectra at room temperature were measured using an Edinburgh FS980 fluorescence spectrometer. Figure 5 As shown; Eu can be observed from the emission spectrum 2+ 4f of ions 6 5d 1 -4f 7 The transition is a typical broad-peak emission with a central wavelength of 508nm. The excitation spectrum covers a wide band of 250-480nm. What is important is that the excitation peak is at 365nm, which can effectively match the 365nm ultraviolet chip widely used on the market, which is conducive to market application.

[0065] from Figure 6 It can be seen that the microcrystalline glass prepared in this embodiment has excellent stability. After being soaked in water for 60 days (60 days) at room temperature, the luminescence intensity only decreases by 3% compared with not soaking in water (i.e., 0 days). In addition, the microcrystalline glass prepared in this embodiment has excellent luminescence performance, and the quantum efficiency reaches 90%.

[0066] Example 2

[0067] A glass-ceramic comprising Ba2SiO4:Eu 2+ Single crystal phase.

[0068] A method for preparing glass-ceramics comprises the following steps:

[0069] S1. Weigh the required raw materials SiO2, BaO, and Eu2O3 according to the molar fractions of 45 mol% SiO2, 54.95 mol% BaO, and 0.05 mol% Eu2O3, mix and grind them for 30 minutes, and place the mixed and ground raw materials into a crucible;

[0070] S2. Place the crucible with the raw materials in a large crucible with a lid covered with activated carbon powder as a reducing atmosphere, keep it in a muffle furnace at 1600℃ for 1 hour to melt it, and then slowly cool it from 1600℃ to room temperature over 9 hours in the muffle furnace to obtain a block of Ba2SiO4:Eu 2+ Single crystal phase glass-ceramics.

[0071] Figure 7 1 is a normalized excitation and emission spectrum of the glass-ceramics prepared in Example 2 of the present invention.

[0072] from Figure 1 It can be seen from the X-ray diffraction peaks that Ba2SiO4:Eu 2+ Single crystal phase.

[0073] Under the excitation of 365nm wavelength violet light, the glass-ceramics prepared in this embodiment exhibits bright green luminescence. The normalized excitation and emission spectra at room temperature are measured using an Edinburgh FS980 fluorescence spectrometer. Figure 7As shown; the emission spectrum can be observed Eu 2+ 4f of ions 6 5d 1 -4f 7 The transition is a typical broad-peak emission with a central wavelength of 508 nm. The excitation spectrum covers a wide band of 250-480 nm, and the excitation peak is at 365 nm.

[0074] Example 3

[0075] A glass-ceramic comprising Ba2SiO4:Eu 2+ Single crystal phase.

[0076] A method for preparing glass-ceramics comprises the following steps:

[0077] S1. Weigh the required raw materials SiO2, BaO, and Eu2O3 according to the molar fractions of 45 mol% SiO2, 54.5 mol% BaO, and 0.5 mol% Eu2O3, mix and grind them for 30 minutes, and place the mixed and ground raw materials into a crucible;

[0078] S2. Place the crucible with the raw materials in a large crucible with a lid covered with activated carbon powder as a reducing atmosphere, keep it in a muffle furnace at 1600℃ for 1 hour to melt it, and then slowly cool it from 1600℃ to room temperature over 9 hours in the muffle furnace to obtain a block of Ba2SiO4:Eu 2+ Single crystal phase glass-ceramics.

[0079] Figure 8 3 are normalized excitation and emission spectra of the glass-ceramics prepared in Example 3 of the present invention.

[0080] from Figure 1 It can be seen from the X-ray diffraction peaks that Ba2SiO4:Eu 2+ Single crystal phase.

[0081] Under the excitation of 365nm wavelength violet light, the glass-ceramics prepared in this embodiment exhibits bright green luminescence. The normalized excitation and emission spectra at room temperature are measured using an Edinburgh FS980 fluorescence spectrometer. Figure 8 As shown; the emission spectrum can be observed Eu 2+ 4f of ions 6 5d 1 -4f 7 The transition is a typical broad-peak emission with a central wavelength of 508 nm. The excitation spectrum covers a wide band of 250-480 nm, and the excitation peak is at 365 nm.

[0082] Example 4

[0083] A glass-ceramic comprising Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ Twin crystal phase.

[0084] A method for preparing glass-ceramics comprises the following steps:

[0085] S1. Weigh the required raw materials SiO2, BaO, and Eu2O3 according to the molar fractions of 45 mol% SiO2, 54 mol% BaO, and 1 mol% Eu2O3, mix and grind them for 30 minutes, and place the mixed and ground raw materials in a crucible;

[0086] S2. Place the crucible with the raw materials in a large crucible with a lid covered with activated carbon powder as a reducing atmosphere, keep it in a muffle furnace at 1600℃ for 1 hour to melt it, and then slowly cool it from 1600℃ to room temperature over 8 hours to obtain a block of Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ Glass-ceramics with twin crystal phases.

[0087] Figure 9 Graphs 4 and 5 are normalized excitation and emission spectra of the glass-ceramics prepared in Example 4 of the present invention.

[0088] from Figure 1 It can be seen from the X-ray diffraction peaks that Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ Twin crystal phase.

[0089] Under the excitation of 365nm wavelength violet light, the glass-ceramics prepared in this embodiment exhibits bright green luminescence. The normalized excitation and emission spectra at room temperature are measured using an Edinburgh FS980 fluorescence spectrometer. Figure 9 As shown; the emission spectrum can be observed Eu 2+ 4f of ions 6 5d 1 -4f 7 The transition is a typical broad-peak emission with a central wavelength of 508 nm. The excitation spectrum covers a wide band of 250-480 nm, and the excitation peak is at 365 nm.

[0090] Comparative Example 1

[0091] A method for preparing glass, comprising the following steps:

[0092] S1. Weigh the required raw materials SiO2, BaO, and Eu2O3 according to the molar fractions of 45 mol% SiO2, 54.8 mol% BaO, and 0.2 mol% Eu2O3, mix and grind them for 30 minutes, and place the mixed and ground raw materials in a crucible;

[0093] S2. Place the crucible containing the raw materials in a large crucible with a lid covered with activated carbon powder as a reducing atmosphere, keep the crucible at 1400°C in a muffle furnace for 1 hour, and then slowly cool the crucible from 1400°C to room temperature over 9 hours to obtain the product.

[0094] Figure 10 1 is the XRD pattern of the amorphous glass prepared in Comparative Example 1 of the present invention.

[0095] In this comparative example, due to the low melting temperature, bulk glass-ceramics could not be obtained, and only bulk amorphous glass could be obtained (see Figure 10 ).

[0096] Comparative Example 2

[0097] A method for preparing glass-ceramics comprises the following steps:

[0098] S1. Weigh the required raw materials SiO2, BaO, and Eu2O3 according to the molar fractions of 50 mol% SiO2, 49.5 mol% BaO, and 0.5 mol% Eu2O3, mix and grind them for 30 minutes, and place the mixed and ground raw materials into a crucible;

[0099] S2. Place the crucible with the raw materials in a large crucible with a lid covered with activated carbon powder as a reducing atmosphere, keep it in a muffle furnace at 1600℃ for 1 hour to melt it, and then slowly cool it from 1600℃ to room temperature over 9 hours in the muffle furnace to obtain a block containing BaSiO3:Eu 2+ Single crystal phase glass-ceramics.

[0100] Comparative Example 3

[0101] A method for preparing glass, comprising the following steps:

[0102] S1. Weigh the required raw materials SiO2, BaO, and Eu2O3 according to the molar fractions of 70 mol% SiO2, 29.5 mol% BaO, and 0.5 mol% Eu2O3, mix and grind them for 30 minutes, and place the mixed and ground raw materials into a crucible;

[0103] S2. Place the crucible containing the raw materials in a large crucible with a lid covered with activated carbon powder as a reducing atmosphere, and keep it warm in a muffle furnace at 1600°C for 1 hour to melt it. After melting, slowly cool it from 1600°C to room temperature in the muffle furnace over 9 hours to obtain a block of amorphous glass.

[0104] A display device includes the microcrystalline glass of embodiment 1.

[0105] A lighting device comprises the glass-ceramic of embodiment 2.

[0106] On the basis of the above embodiments and within the scope of protection requested by the present invention, changes to the technical solutions of the present invention, such as changes in the amount of raw materials of the present invention, temperature and time, etc., which do not require creative labor, all fall within the scope of protection of the present invention.

Claims

1. A glass-ceramic, characterized in that: Including Ba2SiO4:Eu 2+ Single crystal phase, or Ba2SiO4:Eu 2+ and BaSiO3:Eu 2 + at least one of the twin crystal phases; The Ba2SiO4:Eu 2+ The single crystal phase has a long strip morphology, and the Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ The twin crystal phase has an elongated stripe-like morphology.

2. The glass-ceramic according to claim 1, characterized in that The Ba2SiO4:Eu 2+ Single crystal phase, Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ The grain length of the twin crystal phase is 50-550 μm.

3. The glass-ceramic according to claim 1, characterized in that The microcrystalline glass can emit a broadband spectrum in the 420 to 650 nm wavelength range under 365 nm light excitation.

4. The glass-ceramic according to claim 1, characterized in that The quantum efficiency of the microcrystalline glass is not less than 88%.

5. The glass-ceramic according to claim 1, characterized in that: After the microcrystalline glass is immersed in water for 60 days, the luminous intensity decreases by no more than 3%.

6. The method for preparing glass-ceramics according to any one of claims 1 to 5, characterized in that: The following steps are involved: Weighing SiO2, BaO, and Eu2O3 raw materials, then mixing them, heating and melting them under a reducing atmosphere, and then cooling them to obtain the microcrystalline glass; In the raw materials, the molar percentage of SiO2 is 40-60%, the molar percentage of BaO is 40-60%, the molar percentage of BaO is greater than the molar percentage of SiO2, and the sum of the raw material components is 100%; The heating and melting temperature exceeds 1500°C.

7. The preparation method according to claim 6, characterized in that In the raw materials, the molar percentage of Eu2O3 is 0.01-2%.

8. The preparation method according to claim 6, characterized in that The heating and melting temperature is 1580-1650° C., and the heating and melting temperature of 1580-1650° C. is kept at this temperature for 0.8-6 hours; and / or, the reducing atmosphere is selected from at least one of H 2 , CO or carbon powder.

9. A display or lighting device, characterized in that: The invention comprises the glass-ceramics as described in any one of claims 1 to 5.

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