Glass ceramic, preparation method therefor and use thereof

Abstract

The present invention relates to the technical field of solid light-emitting materials, and provides a glass ceramic, a preparation method therefor and a use thereof. The glass ceramic comprises at least one of a Ba2SiO4:Eu2+ single crystal phase, or a Ba2SiO4:Eu2+ and BaSiO3:Eu2+ double crystal phase. The glass ceramic has excellent stability and light-emitting properties, can be widely used to the field of display or lighting, and is particularly applicable to the fields of outdoor display and high-power lighting.

Description

Microcrystalline glass and preparation method and application thereof TECHNICAL FIELD

[0001] The present application belongs to the technical field of solid-state luminescent materials, and particularly relates to a microcrystalline glass and a preparation method and application thereof. BACKGROUND

[0002] At present, solid-state lighting is widely used due to its comprehensive advantages such as energy saving, environmental protection, compactness and long service life. Solid-state lighting refers to a technology in which solid-state electronic components are used as excitation sources, and light emitting diodes (LEDs) and laser diodes (LDs) are taken as representatives. Due to the limitations of the stimulated characteristics of semiconductors and lasers, it is impossible to obtain continuous white light spectrum by simply relying on solid-state electronic components. In order to obtain continuous white light spectrum, it is necessary to couple luminescent materials with LED / LD chips to obtain white light illumination devices. For example, the white light LED (WLED) and LD illumination devices on the market are composed of blue LED / LD chips and yellow YAG:Ce phosphors. 3+

[0003] For high-power lighting, the heat generated due to energy loss (such as photoelectric energy conversion, Stokes shift of luminescent materials) will increase sharply. It has been reported that the cumulative heat dissipation of a high-power LED chip during operation can even exceed 200℃, and under the irradiation of a 10W blue light LD, the internal temperature of the LD device can reach 260℃ within 10 minutes. Under such long-term high-temperature irradiation, the phosphor will face problems such as thermal quenching and decrease in luminous efficiency, and will inevitably bring serious problems such as color shift and decrease in luminous efficiency. In addition, under the irradiation of a high-power chip, the aging and yellowing of organic adhesives such as resins or silicon resins with poor heat resistance will be accelerated, and even ablation will occur. Therefore, the heat dissipation problem has become one of the main bottlenecks restricting the development of high-power solid-state lighting. On the basis of existing LED / LD chip technology, it is a severe challenge to explore luminescent materials with high luminous efficiency and excellent thermal stability.

[0004] Therefore, more and more scientists have begun to focus on solid-state luminescent materials with excellent optical properties. Solid-state luminescent materials mainly include single crystals, ceramics and glasses. Single crystals and ceramics are greatly limited in their wide application in the market due to high manufacturing costs and inability to mass-produce, while glasses have the disadvantage of low luminous efficiency due to the amorphous structure.

[0005] Therefore, it is urgent to provide a new solid-state luminescent material.

[0006] SUMMARY

[0007] ​The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a microcrystalline glass, a preparation method and application thereof. The microcrystalline glass has excellent stability and luminescence performance, and can be widely applied in the field of display or illumination, especially suitable for outdoor display and high-power illumination field.

[0008] The microcrystalline glass is prepared by controlling crystallization of specific component raw materials during heating, and can be prepared into a microcrystalline glass (glass ceramic) containing a large amount of microcrystalline phase (belonging to fluorescent powder crystal) and glass phase. 2+ The rare earth (Eu 2+ ) doped microcrystalline glass combines the advantages of fluorescent powder crystal and glass, has high luminescent efficiency, excellent thermal stability and high transparency, and has the advantages of hard and compact texture, flexible component control, corrosion resistance, easy processing and molding, low cost and large-scale production. The microcrystalline glass has a viscous network structure, so that the microcrystalline is uniformly dispersed. Therefore, the microcrystalline glass has the above advantages and can be applied in outdoor display and high-power illumination field.

[0009] The first aspect of the present application provides a microcrystalline glass.

[0010] Specifically, a microcrystalline glass comprises at least one of Ba2SiO4:Eu 2+ single crystal phase, or Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ double crystal phase.

[0011] Preferably, the Ba2SiO4:Eu 2+ single crystal phase has an elongated morphology.

[0012] Preferably, the Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ double crystal phase has an elongated morphology.

[0013] Preferably, the Ba2SiO4:Eu 2+ single crystal phase, Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ double crystal phase has a grain length of 50-550 μm, and further preferably 100-500 μm.

[0014] Preferably, the microcrystalline glass can emit strong broadband light spectrum in the range of 420 to 650 nm under 365 nm light excitation, and further the main emission peak is at 508 nm.

[0015] Preferably, the quantum efficiency of the microcrystalline glass is not less than 88%, for example, 88-92%.

[0016] Preferably, the intensity of the luminescence of the glass-ceramics does not decrease more than 3% after 60 days of immersion in water. For example, the intensity of the luminescence decreases 1-3%.

[0017] The second aspect of the present application provides a method for preparing the glass-ceramics.

[0018] Specifically, the method for preparing the glass-ceramics comprises the following steps:

[0019] Weighing SiO2, BaO and Eu2O3 raw materials, then mixing, heating and melting under a reducing atmosphere, and then cooling to obtain the glass-ceramics.

[0020] 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.

[0021] The temperature of the heating and melting is more than 1500℃.

[0022] Preferably, in the raw materials, the molar percentage of Eu2O3 is 0.01-2%, and further preferably 0.1-0.2%.

[0023] 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.

[0024] 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%.

[0025] Preferably, the temperature of the heating and melting is 1580-1650℃, and further preferably 1580-1600℃.

[0026] Preferably, the heating and melting temperature is 1580-1650℃, and further preferably the heating and melting temperature is 1580-1600℃.

[0027] Preferably, the reducing atmosphere is selected from at least one of H2, CO or carbon powder.

[0028] Preferably, the mixing process is carried out by grinding. For example, grinding for 20-30 minutes.

[0029] Preferably, the cooling is natural cooling to room temperature, for example, cooling to room temperature with a muffle furnace.

[0030] Preferably, the cooling time is 8-10 hours.

[0031] The third aspect of the present application provides a use of the glass-ceramics.

[0032] A display or lighting device comprising the glass-ceramics.

[0033] Compared with the prior art, the present application has the following advantages:

[0034] (1) The present application adopts specific preparation conditions (raw material ratio and heating and melting temperature) to prepare the transparent fluorescent Ba2SiO4:Eu 2+ monocrystal phase or Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ bimorph crystal phase glass-ceramics, which is hard, compact and uniform in texture, has stable physical and chemical properties (after being immersed in water for 60 days, the luminescence intensity decreases by no more than 3%), and can emit strong green light under ultraviolet excitation (quantum efficiency is not less than 88%).

[0035] (2) The present application is economical and practical, and uses SiO2, BaO and Eu2O3 as raw materials to prepare the glass-ceramics, which has low preparation cost.

[0036] (3) The present application prepares a transparent fluorescent glass-ceramics containing long strip-shaped crystal morphology with adjustable structure, and the crystal phase in the glass-ceramics can be adjusted from Ba2SiO4:Eu 2+ monocrystal phase to Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ bimorph crystal phase.

[0037] (4) The glass-ceramics of the present application is prepared by one-step method, which has simple process, low cost, no toxicity and no pollution, and excellent luminescence performance, and can be developed and applied as green fluorescent solid luminescence material in laser lighting. BRIEF DESCRIPTION OF DRAWINGS

[0038] Fig. 1 is an XRD pattern of the glass-ceramics prepared in Example 1 of the present application;

[0039] Fig. 2 is a digital photograph of the glass-ceramics prepared in Example 1 of the present application;

[0040] Fig. 3 is a morphology photograph taken under an optical microscope of the glass-ceramics prepared in Example 1 of the present application;

[0041] Fig. 4 is a morphology photograph taken under a scanning electron microscope (SEM) of the glass-ceramics prepared in Example 1 of the present application;

[0042] Figure 5 is a normalized excitation and emission spectrum of the microcrystalline glass prepared in Example 1 of the present application;

[0043] Figure 6 is a comparison of the spectral intensity of the microcrystalline glass prepared in Example 1 of the present application at 0 day and 60 days in water, respectively;

[0044] Figure 7 is a normalized excitation and emission spectrum of the microcrystalline glass prepared in Example 2 of the present application;

[0045] Figure 8 is a normalized excitation and emission spectrum of the microcrystalline glass prepared in Example 3 of the present application;

[0046] Figure 9 is a normalized excitation and emission spectrum of the microcrystalline glass prepared in Example 4 of the present application;

[0047] Figure 10 is an XRD pattern of the amorphous glass prepared in Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0048] In order to make the skilled in the art more clearly understand the technical solutions described in the present application, the following examples are listed for illustration. It should be pointed out that the following examples do not constitute a limitation on the scope of protection required by the present application.

[0049] The raw materials, reagents or devices used in the following examples, if not specifically stated, can be obtained from conventional commercial channels, or can be obtained by existing known methods.

[0050] In Figure 1, "Intensity" represents intensity, 2θ represents diffraction angle, "degree" represents degree, "PDF#70-2113" represents the standard card of Ba2SiO4, and "PDF#70-2112" represents the standard card of BaSiO3.

[0051] In Figures 5 to 9, "Intensity" represents intensity, and "Wavelength" represents wavelength.

[0052] In Figure 6, "day" represents day.

[0053] In Figure 10, "Intensity" represents intensity, 2θ represents diffraction angle, and "degree" represents degree.

[0054] Example 1

[0055] A microcrystalline glass comprising Ba2SiO4:Eu 2+ Single crystal phase.

[0056] A method for preparing a microcrystalline glass, comprising the following steps:

[0057] S1, the required raw materials SiO2, BaO, Eu2O3 are weighed according to the molar fractions of 45 mol% SiO2, 54.8 mol% BaO and 0.2 mol% Eu2O3, and mixed and ground for 30 min, and the mixed and ground raw materials are placed in a crucible;

[0058] S2, the crucible containing the raw materials is placed in a covered large crucible filled with activated carbon powder as a reducing atmosphere, and is kept at 1600°C in a muffle furnace for 1 h to melt, and after melting, the muffle furnace is slowly cooled from 1600°C to room temperature over 9 h to obtain a bulk Ba2SiO4:Eu containing glass-ceramic 2+ Monocrystalline phase glass-ceramic.

[0059] Fig. 1 is an XRD pattern of the glass-ceramic prepared in Example 1 of the present application; Fig. 2 is a digital photograph of the glass-ceramic prepared in Example 1 of the present application; Fig. 3 is a morphology photograph taken under an optical microscope of the glass-ceramic prepared in Example 1 of the present application; Fig. 4 is a morphology photograph taken under a scanning electron microscope (SEM) of the glass-ceramic prepared in Example 1 of the present application; Fig. 5 is a normalized excitation and emission spectrum of the glass-ceramic prepared in Example 1 of the present application; and Fig. 6 is a comparison of the spectral intensity of the glass-ceramic prepared in Example 1 of the present application at 0 days and 60 days in water, respectively.

[0060] As can be seen from the X-ray diffraction peaks in Fig. 1, in the prepared glass-ceramic, Ba2SiO4:Eu 2+ Monocrystalline phase.

[0061] The prepared glass-ceramic still has certain transparency when the thickness is 2 mm, and the crystals with long strip morphology are embedded in the glass (see Fig. 2).

[0062] The successfully prepared glass-ceramic with long strip morphology is clearly observed under an optical microscope (see Fig. 3).

[0063] The crystals with long strip morphology are further observed under a scanning electron microscope (SEM), and the grain length thereof is about 100-500 μm (see Fig. 4).

[0064] Under 365 nm wavelength violet light excitation, the glass-ceramic prepared in the present example exhibits bright green light emission, and the normalized excitation and emission spectrum thereof at room temperature is shown in Fig. 5 measured by an Edinburgh FS980 fluorescence spectrometer; from the emission spectrum, it can be observed that the Eu 2+ ions 4f 6 5d 1 -4f 7The transition is a typical wide peak emission, the center wavelength of which is located at 508 nm, the excitation spectrum covers a wide band of 250-480 nm, and importantly, the excitation peak is located at 365 nm, which can effectively match the widely used 365 nm ultraviolet chip on the market, and is conducive to market application.

[0065] As can be seen from FIG. 6, the microcrystalline glass prepared in the embodiment has excellent stability, and after being soaked in water at room temperature for 60 days, the luminous intensity only decreases by 3% compared with that without being soaked in water (i.e., 0 day); in addition, the microcrystalline glass prepared in the embodiment has excellent luminous performance, and the quantum efficiency reaches 90%.

[0066] Embodiment 2

[0067] A microcrystalline glass, comprising Ba2SiO4:Eu 2+ Single crystal phase.

[0068] A preparation method of a microcrystalline glass, comprising the following steps:

[0069] S1, the required raw materials SiO2, BaO and Eu2O3 are weighed according to the molar fractions of 45 mol% SiO2, 54.95 mol% BaO and 0.05 mol% Eu2O3, and mixed and ground for 30 min, and the mixed and ground uniform raw materials are placed in a crucible;

[0070] S2, the crucible containing the raw materials is placed in a covered large crucible filled with activated carbon powder as a reducing atmosphere, and is kept at 1600 DEG C for 1 h to melt, and after melting, the muffle furnace is slowly cooled from 1600 DEG C to room temperature for 9 h, to obtain a block-shaped Ba2SiO4:Eu 2+ Single crystal phase microcrystalline glass.

[0071] FIG. 7 is a normalized excitation and emission spectrum diagram of the microcrystalline glass prepared in Embodiment 2 of the application.

[0072] As can be seen from the X-ray diffraction peaks in FIG. 1, in the microcrystalline glass prepared in the embodiment, Ba2SiO4:Eu 2+ Single crystal phase.

[0073] Under the excitation of 365 nm wavelength violet light, the microcrystalline glass prepared in the embodiment exhibits bright green light emission, and the normalized excitation and emission spectrum thereof at room temperature is measured by Edinburgh FS980 fluorescence spectrometer and shown in FIG. 7; the emission spectrum can observe the 4f 2+ ions of Eu 6 5d 1 -4f 7 transition, which is a typical wide peak emission, the center wavelength of which is located at 508 nm, the excitation spectrum covers a wide band of 250-480 nm, and the excitation peak is located at 365 nm.

[0074] Example 3

[0075] A microcrystalline glass comprising Ba2SiO4:Eu 2+ monocrystal phase.

[0076] A method for preparing a microcrystalline glass, comprising the following steps:

[0077] S1, weighing 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, and mixing and grinding for 30 min, and placing the mixed and ground raw materials in a crucible;

[0078] S2, placing the crucible containing the raw materials in a covered large crucible filled with activated carbon powder as a reducing atmosphere, and slowly cooling from 1600℃ to room temperature for 9 hours in a muffle furnace under the condition of 1600℃ for 1 h to make it melt, and obtaining a blocky Ba2SiO4:Eu 2+ monocrystal phase.

[0079] Figure 8 is a normalized excitation and emission spectrum diagram of the microcrystalline glass prepared in Example 3 of the present application.

[0080] As can be seen from the X-ray diffraction peaks in Figure 1, in the microcrystalline glass prepared in this embodiment, Ba2SiO4:Eu 2+ monocrystal phase.

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

[0082] Example 4

[0083] A microcrystalline glass comprising Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ bimorphous phase.

[0084] A method for preparing a microcrystalline glass, comprising the following steps:

[0085] S1, the required raw materials SiO2, BaO and Eu2O3 are weighed according to the molar fractions of 45 mol% SiO2, 54 mol% BaO and 1 mol% Eu2O3, and mixed and ground for 30 min, and the mixed and ground raw materials are placed in a crucible;

[0086] S2, the crucible containing the raw materials is placed in a large crucible covered with activated carbon powder as a reducing atmosphere, and is kept at 1600°C in a muffle furnace for 1 h to melt, and after melting, the muffle furnace is slowly cooled from 1600°C to room temperature over 8 h to obtain a block-shaped Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ double crystal phase glass.

[0087] Figure 9 is a normalized excitation and emission spectrum of the glass-ceramic prepared in Example 4 of the present application.

[0088] As can be seen from the X-ray diffraction peaks in Figure 1, in the glass-ceramic prepared in this example, Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ double crystal phase have been precipitated.

[0089] Under 365 nm wavelength violet light excitation, the glass-ceramic prepared in this example exhibits bright green luminescence, and the normalized excitation and emission spectra thereof at room temperature measured with an Edinburgh FS980 fluorescence spectrometer are shown in Figure 9; the emission spectrum can observe the 4f 2+ -4f 6 5d 1 transition of Eu 7 ion, which is a typical broad peak emission with a center wavelength of 508 nm, and the excitation spectrum covers a wide wavelength range of 250-480 nm with an excitation peak at 365 nm.

[0090] Comparative Example 1

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

[0092] S1, the required raw materials SiO2, BaO and Eu2O3 are weighed according to the molar fractions of 45 mol% SiO2, 54.8 mol% BaO and 0.2 mol% Eu2O3, and mixed and ground for 30 min, and the mixed and ground raw materials are placed in a crucible;

[0093] S2, the crucible containing the raw materials is placed in a large crucible covered with activated carbon powder as a reducing atmosphere, and is kept at 1400°C in a muffle furnace for 1 h, and then slowly cooled from 1400°C to room temperature over 9 h with the muffle furnace to obtain the product.

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

[0095] The comparative example cannot obtain bulk microcrystalline glass due to the low temperature of melting, and only bulk amorphous glass can be obtained (see Figure 10).

[0096] Comparative Example 2

[0097] A preparation method of a microcrystalline glass, comprising the following steps:

[0098] S1, the required raw materials SiO2, BaO and Eu2O3 are weighed according to the molar fractions of 50 mol% SiO2, 49.5 mol% BaO and 0.5 mol% Eu2O3, and mixed and ground for 30 min, and the mixed and ground uniform raw materials are placed in a crucible;

[0099] S2, the crucible containing the raw materials is placed in a large crucible covered with activated carbon powder as a reducing atmosphere, and is kept at 1600℃ for 1 h to melt in a muffle furnace, and after melting, the muffle furnace is slowly cooled from 1600℃ to room temperature for 9 h, to obtain bulk BaSiO3:Eu containing glass. 2+ Monocrystalline phase microcrystalline glass.

[0100] Comparative Example 3

[0101] A preparation method of a glass, comprising the following steps:

[0102] S1, the required raw materials SiO2, BaO and Eu2O3 are weighed according to the molar fractions of 70 mol% SiO2, 29.5 mol% BaO and 0.5 mol% Eu2O3, and mixed and ground for 30 min, and the mixed and ground uniform raw materials are placed in a crucible;

[0103] S2, the crucible containing the raw materials is placed in a large crucible covered with activated carbon powder as a reducing atmosphere, and is kept at 1600℃ for 1 h to melt in a muffle furnace, and after melting, the muffle furnace is slowly cooled from 1600℃ to room temperature for 9 h, to obtain bulk amorphous glass.

[0104] A display device comprising the microcrystalline glass of Example 1.

[0105] A lighting device comprising the microcrystalline glass of Example 2.

[0106] On the basis of the above examples, and within the scope of protection claimed by the present application, the technical solutions of the present application are changed, for example, the amount of raw materials, temperature and time of the present application are changed without the need for creative labor improvements, which all belong to the protection scope of the present application.

Claims

1. A microcrystalline glass characterized in that, including Ba2Si04:Eu 2+ single crystal phase, or Ba2Si04:Eu 2+ and BaSi03:Eu 2+ at least one of a double crystal phase.

2. The glass-ceramic according to claim 1, characterized in that, The Ba2SiO4:Eu 2+ The single crystal phase has an elongated morphology; and / or, the Ba2SiO4:Eu 2+ and BaSiO3:Eu 2+ The double crystal phase has an elongated morphology.

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

4. The glass-ceramic according to claim 1, characterized in that, The microcrystalline glass can emit a broadband spectrum of light in the 420-650 nm band under excitation by 365 nm light.

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

6. The glass-ceramic according to claim 1, characterized in that, The luminous intensity of the microcrystalline glass decreases by not more than 3% after being soaked in water for 60 days.

7. The method of manufacturing the microcrystalline glass according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: The SiO2, BaO and Eu2O3 raw materials are weighed and then mixed, and then melted under a reducing atmosphere, and then cooled 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%, and the molar percentage of BaO is greater than the molar percentage of SiO2. The melting temperature is higher than 1500 DEG C.

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

9. The preparation method according to claim 7, characterized in that, The melting temperature is 1580-1650 DEG C, and the temperature is maintained for 0.8-6 hours at the melting temperature of 1580-1650 DEG C; and / or the reducing atmosphere is selected from at least one of H2, CO or carbon powder.

10. A display or illumination device, characterized in that The microcrystalline glass according to any one of claims 1-6.

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