A Bi 3+ Doped blue light glass-ceramics, method of making and use thereof

Abstract

The application discloses a kind of Bi 3+ Doped blue light glass ceramic and its preparation method and application, Bi 3+ Doped blue light glass ceramic composition is SiO2-BaO-SrO-Al2O3-B2O3-La2O3-P2O5-Bi2O3, the molar percentage of each component is respectively: SiO2:25~45%, SrO:5~50%, BaO:5~50%, B2O3:5~20%, La2O3:2~8%, Al2O3:1~8%, P2O5:2~10%, Bi2O3:0.1~2.5%.The application is Bi 3+ As activator, P2O5 is crystal nucleus agent, and the prepared Bi 3+ Doped glass ceramic not only has excellent chemical stability and thermal stability, but also has high transmittance and luminous efficiency, Bi 3+ As luminescent center, into the crystallite environment, can occupy the 4f and 6h lattice position of Ba4La6O(SiO4)6 crystal, under the excitation of 325 nm ultraviolet light, blue light emission with center located at 460 nm can be realized, and it has good application prospect in the field of near-ultraviolet light excitation white LED.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of luminescent materials, and particularly relates to a Bi 3+ doped blue light glass ceramic, a preparation method and application thereof. BACKGROUND

[0002] As is known, white light LED, as the fourth generation of illumination light source, has been widely applied to many fields such as illumination and display due to its advantages of energy saving, environmental protection, long service life, small size and the like. At present, the phosphor converted LED based on the combination of chip and phosphor has the advantages of relatively low production cost, simple process and easy mass production, and thus occupies a dominant position in the LED market. Among them, the commercialized scheme is to use a blue light LED chip to excite YAG:Ce phosphor to generate yellow light, and combine the remaining blue light with the yellow light to obtain white light. However, due to the lack of red light in the spectrum of the white light LED, there are problems of low color rendering index and high color temperature. In order to solve this problem, in recent years, researchers tend to use a near-ultraviolet LED chip to excite three-primary-color phosphors, and obtain white light with a desired color temperature by adjusting the proportion of the phosphors. However, the current three-primary-color phosphors mostly use rare earth ions as activators. Since the rare earth ions have a strong absorption band in the visible light region, when the phosphors are mixed for use, visible light reabsorption occurs, which greatly limits the color rendering and luminous efficiency of the device. On the other hand, the rare earth resources are limited and the separation and purification cost is high, so it is necessary to develop new non-rare earth fluorescent materials using transition metal ions such as Bi 3+ as activators, which has attracted extensive attention of researchers. Unlike rare earth ions, the absorption band of Bi 3+ is located in the ultraviolet region, which can avoid the problem of visible light reabsorption. In addition, the 6s electron of Bi 3+ is exposed, which is very sensitive to the crystal field environment, and the parity-allowed transition exhibits broadband strong light emission and can realize tunable emission from ultraviolet to red.

[0003] Oxyapatite structure silicates have excellent physical and chemical stability, and two types of (4f and 6h) sites in the structure can accommodate rare earth and transition metal ions. In recent years, great progress has been made in the research of Bi 3+ doped silicate oxyapatite phosphor, and researchers have synthesized a series of Bi 3+ activated blue-green and blue light phosphors by using high-temperature solid phase method and sol-gel combustion method. Compared with polycrystalline phosphor, fluorescent glass ceramic is a kind of composite material composed of micron or nanoscale fluorescent crystals and glass phase, which shows obvious advantages in LED packaging and can solve the problems such as easy aging and yellowing of organic packaging materials such as silicone. Therefore, transparent glass ceramic containing oxyapatite nanocrystals is prepared by using glass controlled crystallization, and then Bi 3+It is of great significance to develop new blue fluorescent materials with near-ultraviolet excitation for the coordination environment of Bi SUMMARY

[0004] In view of the problems of low color rendering index, high color temperature, poor heat resistance and easy aging and yellowing of organic packaging materials of the existing commercial white light LED, the application provides a Bi 3+ Doped blue light glass ceramic and a preparation method and application thereof, wherein Bi 3+ is used as an activator, and P2O5 is used as a crystal nucleus agent. 3+ The doped glass ceramic has excellent chemical stability and thermal stability, high transmittance and high luminous efficiency, and Bi 3+ as a luminescent center, enters a microcrystalline environment, occupies 4f and 6h lattice positions of Ba4La6O(SiO4)6 crystals, and realizes blue light emission centered at 460 nm under ultraviolet light excitation at 325 nm, and has good application prospects in the field of near-ultraviolet light excitation white light LED.

[0005] The application is achieved by the following technical solutions.

[0006] A Bi 3+ doped blue light glass ceramic, wherein Bi 3+ The composition of the Bi-doped blue light glass ceramic is SiO2-BaO-SrO-Al2O3-B2O3-La2O3-P2O5-Bi2O3, and the molar percentages of the components are as follows: SiO2: 25-45%, SrO: 5-50%, BaO: 5-50%, B2O3: 5-20%, La2O3: 2-8%, Al2O3: 1-8%, P2O5: 2-10%, and Bi2O3: 0.1-2.5%.

[0007] Further, the crystal phase of the Bi 3+ doped blue light glass ceramic is pure-phase oxyapatite Ba4La6O(SiO4)6, and the grain size is 20-30 nm.

[0008] The application further discloses a preparation method of the Bi 3+ doped blue light glass ceramic.

[0009] (1) The raw materials corresponding to the components of the Bi 3+ doped blue light glass ceramic are weighed according to the proportions and uniformly mixed, and then placed in a crucible, and then heated in a high-temperature furnace at 1400-1500 o C for 1-4 h, the homogenized melt is formed on a preheated mold, and then moved to a muffle furnace at 580-650 o C for annealing, and then cooled to room temperature in the furnace after the annealing is completed to obtain a base glass block.

[0010] (2) the base glass block in step (1) is placed in a muffle furnace, and is raised to 720-850 o at a temperature raising rate of 10-20 K / min, and is kept for 4-48 hours, and then is cooled to room temperature, to obtain a Bi 3+ doped blue light glass ceramic.

[0011] Further, in step (1), SrO and BaO are introduced in the form of carbonates, B2O3 is introduced in the form of boric acid, P2O5 is introduced in the form of ammonium dihydrogen phosphate, Bi2O3 is introduced in the form of bismuth-containing oxide or bismuth salt, and SiO2, Al2O3 and La2O3 are introduced in the form of oxides.

[0012] Further, the uniform mixing is grinding and stirring in an agate mortar until uniform.

[0013] Further, in step (1), the preheated mold is a brass mold preheated to 150-220℃.

[0014] Further, in step (1), the annealing time is 1-3h.

[0015] The Bi 3+ doped blue light glass ceramic disclosed in the application has the advantages that:

[0016] The application has the following beneficial effects:

[0017] (1) Blue light fluorescent powder excited by ultraviolet light is mostly realized by doping rare earth (Eu 2+ / Ce 3+ ). These fluorescent powders often have problems of poor stability and visible light reabsorption of rare earth ions; the application uses Bi 3+ as an activator, the absorption band is located in the ultraviolet region, which can be matched with a high-efficiency near-ultraviolet chip, and there is no absorption in the visible region, which can avoid the problem of reabsorption, thereby the luminous efficiency can be significantly improved;

[0018] (2) The Bi 3+ doped blue light glass ceramic disclosed in the application can be excited by ultraviolet light of 275-375 nm, realizes broadband adjustable blue light emission in the range of 375-725 nm, and the strongest emission peak is located at 460 nm;

[0019] (3) The Bi 3+The doped blue light glass ceramic is internally uniformly distributed with a large number of micro-nano scale oxyapatite fluorescent crystals, has high light transmittance, excellent physical and chemical stability and thermal stability, and can solve the problems of aging and yellowing of organic packaging materials, reduction of light transmittance and the like in traditional LED packaging technology, and is a new type of inorganic transparent solid luminescent material which can replace the traditional fluorescent powder packaging type white light LED conversion layer of 'fluorescent powder + epoxy resin / silicone'.

[0020] (4) The prepared Bi 3+ The doped blue light glass ceramic is prepared by using a whole crystallization method, that is, a base glass is first prepared by using a melting method, and then the glass is nucleated and crystallized under suitable heat treatment conditions to obtain a composite material composed of nano-crystals and glass phase, and the method has low production cost, simple process, is suitable for automatic operation and production of various complex-shaped products. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The prepared Bi 3+ The scanning electron microscope image of the doped glass ceramic;

[0022] Figure 2 The prepared Bi 3+ The XRD spectrum of the doped base glass and glass ceramic;

[0023] Figure 3 The transmission spectrum of the glass ceramic prepared for Examples 2-4 and Comparative Example 1;

[0024] Figure 4 The prepared Bi 3+ The room temperature excitation and visible emission spectrum of the doped glass and glass ceramic sample;

[0025] Figure 5 The prepared Bi 3+ The emission spectrum of the doped glass ceramic sample under excitation of light with different wavelengths; Figure 6 The prepared Bi 3+ The emission spectrum of the doped glass ceramic sample under excitation of light with a wavelength of 325 nm. DETAILED DESCRIPTION

[0026] In order for those skilled in the art to better understand the technical solutions of the present application, the technical solutions of the present application will be clearly and completely described below, and other similar embodiments obtained by those skilled in the art without creative labor based on the embodiments in the present application shall all belong to the scope of protection of the present application.

[0027] Example 1

[0028] A Bi3+ A doped blue light glass ceramic (GCB0.3) with a composition of SiO2-BaO-SrO-Al2O3-B2O3-La2O3-P2O5-Bi2O3, and the molar percentage of each component is: SiO2: 28.8%, SrO: 19.2%, BaO: 28.8%, B2O3: 9.6%, La2O3: 4.8%, Al2O3: 4.8%, P2O5: 3.85%, Bi2O3: 0.15%, and the preparation method is specifically as follows:

[0029] (1) According to the above ratio, 30 g of glass liquid is taken as the calculation basis, and the analytical pure silicon dioxide, barium carbonate, strontium carbonate, aluminum oxide, boric acid, lanthanum oxide, ammonium dihydrogen phosphate, and bismuth oxide are accurately weighed and mixed uniformly in a marquis mortar, and then placed in a 50 ml corundum crucible and placed in a 1400 o C high temperature furnace for 1.5 h, and the homogenized melt is poured into a preheated brass mold to form a transparent bulk glass, and then the base glass is transferred to a 590 o C muffle furnace for annealing for 2 h, and finally cooled to room temperature with the furnace, to obtain a base glass block;

[0030] (2) The base glass block obtained in step (1) is cut into small pieces, ground to 2 mm thick, and the surface is polished, and the two polished bulk glasses are placed in a muffle furnace, and then heated to 720 o C at a heating rate of 20 K / min, and heat treated at this temperature for 48 h, and then cooled to room temperature with the furnace, to obtain Bi 3+ doped blue light glass ceramic (GCB0.3); the cross-sectional morphology of the Bi 3+ doped blue light glass ceramic is observed by field emission scanning electron microscope, and the results are shown in Figure 1 , a large number of fine crystals are precipitated in the glass ceramic, the crystal grains are spherical, the size is nanoscale and the distribution is very uniform, and the grain size is 20-30 nm.

[0031] Example 2

[0032] A Bi 3+ doped blue light glass ceramic (GCB0.6) with a composition of SiO2-BaO-SrO-Al2O3-B2O3-La2O3-P2O5-Bi2O3, and the molar percentage of each component is: SiO2: 28.76%, SrO: 19.18%, BaO: 28.76%, B2O3: 9.59%, La2O3: 4.79%, Al2O3: 4.79%, P2O5: 3.84%, Bi2O3: 0.29%, and the preparation method is specifically as follows:

[0033] (1) According to the above ratio, 30 g of glass liquid is taken as the calculation basis, and accurately weighed analytical pure silicon dioxide, barium carbonate, strontium carbonate, aluminum oxide, boric acid, lanthanum oxide, ammonium dihydrogen phosphate, bismuth oxide are mixed uniformly in a agate mortar, then loaded into a 50 ml corundum crucible, placed in a 1400 o C high temperature furnace for 1.5 h, the homogenized melt is poured into a preheated brass mold to form a transparent bulk glass, then the base glass is transferred to a 590 o C muffle furnace for annealing for 2 hours, and finally cooled to room temperature with the furnace, to obtain a base glass block;

[0034] (2) The base glass block obtained in step (1) is cut into small pieces, ground to 2 mm thick, and the surface is polished, and the bulk glass after polishing on both sides is placed in a muffle furnace, then heated to 720 o C at a heating rate of 20 K / min, and heat treated at this temperature for 48 hours, and then cooled to room temperature with the furnace, to obtain a Bi 3+ doped blue light glass ceramic (GCB0.6).

[0035] Example 3

[0036] A Bi 3+ doped blue light glass ceramic (GCB0.9) with a composition of SiO2-BaO-SrO-Al2O3-B2O3-La2O3-P2O5-Bi2O3, and the molar percentage of each component is: SiO2: 28.72%, SrO: 19.15%, BaO: 28.72%, B2O3: 9.57%, La2O3: 4.79%, Al2O3: 4.79%, P2O5: 3.83%, Bi2O3: 0.43%, and the preparation method is specifically as follows:

[0037] (1) According to the above ratio, 30 g of glass liquid is taken as the calculation basis, and accurately weighed analytical pure silicon dioxide, barium carbonate, strontium carbonate, aluminum oxide, boric acid, lanthanum oxide, ammonium dihydrogen phosphate, bismuth oxide are mixed uniformly in a agate mortar, then loaded into a 50 ml corundum crucible, placed in a 1400 o C high temperature furnace for 1.5 h, the homogenized melt is poured into a preheated brass mold to form a transparent bulk glass, then the base glass is transferred to a 590 o C muffle furnace for annealing for 2 hours, and finally cooled to room temperature with the furnace, to obtain a base glass block;

[0038] (2) The base glass block obtained in step (1) is cut into small test samples, ground to 2 mm thick, and the surface is polished. The block glass polished on both sides is placed in a muffle furnace, and then heated to 720 o C at a heating rate of 20 K / min, and heat treated at this temperature for 48 hours, and then cooled to room temperature with the furnace, to obtain Bi 3+ doped blue light glass ceramic (GCB0.9).

[0039] Example 4

[0040] A Bi 3+ doped blue light glass ceramic (GCB1.2) with a composition of SiO2-BaO-SrO-Al2O3-B2O3-La2O3-P2O5-Bi2O3, and the molar percentage of each component is: SiO2: 28.68%, SrO: 19.12%, BaO: 28.68%, B2O3: 9.56%, La2O3: 4.78%, Al2O3: 4.78%, P2O5: 3.83%, Bi2O3: 0.57%, and the preparation method is specifically as follows:

[0041] (1) According to the above ratio, 30 g of glass liquid is taken as the calculation basis, and the analytical pure silicon dioxide, barium carbonate, strontium carbonate, aluminum oxide, boric acid, lanthanum oxide, ammonium dihydrogen phosphate, and bismuth oxide are accurately weighed in a maroon mortar and mixed uniformly, then placed in a 50 ml corundum crucible, and placed in a high-temperature furnace at 1400 o C for 1.5 h, and the homogenized melt is poured into a preheated brass mold to form a transparent block glass, and then the base glass is transferred to a muffle furnace at 590 o C for annealing for 2 hours, and finally cooled to room temperature with the furnace, to obtain a base glass block;

[0042] (2) The base glass block obtained in step (1) is cut into small test samples, ground to 2 mm thick, and the surface is polished. The block glass polished on both sides is placed in a muffle furnace, and then heated to 720 o C at a heating rate of 20 K / min, and heat treated at this temperature for 48 hours, and then cooled to room temperature with the furnace, to obtain Bi 3+ doped blue light glass ceramic (GCB1.2).

[0043] Example 5

[0044] A Bi 3+A doped blue light glass-ceramics (GCB2) has a composition of SiO2-BaO-SrO-Al2O3-B2O3-La2O3-P2O5-Bi2O3, and the molar percentage of each component is: SiO2: 28.57%, SrO: 19.06%, BaO: 28.57%, B2O3: 9.52%, La2O3: 4.76%, Al2O3: 4.76%, P2O5: 3.81%, Bi2O3: 0.95%, and the preparation method is specifically as follows:

[0045] (1) According to the above ratio, 30 g of glass liquid is taken as the calculation basis, and the analytical pure silicon dioxide, barium carbonate, strontium carbonate, aluminum oxide, boric acid, lanthanum oxide, ammonium dihydrogen phosphate and bismuth oxide are accurately weighed, mixed and uniformly ground in an agate mortar, then loaded into a 50 ml corundum crucible, and placed in a 1400 o C high temperature furnace for 1.5 h, and the homogenized melt is poured into a preheated brass mold to form a transparent bulk glass, and then the base glass is transferred to a 590 o C muffle furnace for annealing for 2 hours, and finally cooled to room temperature with the furnace, to obtain a base glass block;

[0046] (2) The base glass block obtained in step (1) is cut into small pieces, ground to 2 mm thick, and the surface is polished, and the bulk glass after polishing on both sides is placed in a muffle furnace, and then heated to 720 o C at a heating rate of 20 K / min, and heat treated at this temperature for 48 hours, and then cooled to room temperature with the furnace, to obtain Bi 3+ doped blue light glass-ceramics (GCB2).

[0047] Comparative Example 1

[0048] A kind of undoped blank glass-ceramics has a composition of SiO2-BaO-SrO-Al2O3-B2O3-La2O3-P2O5-Bi2O3, and the molar percentage of each component is: SiO2: 28.85%, SrO: 19.21%, BaO: 28.85%, B2O3: 9.62%, La2O3: 4.81%, Al2O3: 4.81%, P2O5: 3.85%, and the preparation method is specifically as follows:

[0049] (1) According to the above ratio, 30 g of glass liquid is taken as the calculation basis, and the analytical pure silicon dioxide, barium carbonate, strontium carbonate, aluminum oxide, boric acid, lanthanum oxide, ammonium dihydrogen phosphate are accurately weighed, mixed and uniformly ground in an agate mortar, then loaded into a 50 ml corundum crucible, and placed in a 1400 oThe homogenized melt was poured into a preheated brass mold to form a transparent bulk glass after 1.5 h of heat preservation in a high-temperature furnace at C. Subsequently, the base glass was transferred to a furnace at 590 o C for annealing for 2 h and finally cooled to room temperature in the furnace to obtain a base glass block;

[0050] (2) The base glass block obtained in step (1) was cut into small pieces, ground to a thickness of 2 mm, and the surface was polished. The bulk glass after polishing on both sides was placed in a furnace, and then heated to 720 o C at a heating rate of 20 K / min, and heat treated at this temperature for 48 h, and then cooled to room temperature in the furnace to obtain a Bi 3+ doped blue light glass-ceramics (GCB2).

[0051] The Bi 3+ doped blue light glass-ceramics prepared in Examples 1-5 and the undoped blank glass-ceramics prepared in Comparative Example 1 were crushed and ground, and X-ray diffraction analysis was performed, and the results are shown in Figure 2 From the results, it can be seen that pure-phase oxyapatite (Ba4La6O(SiO4)6, JCPDS No. 00-027-0037) crystals were precipitated in the heat-treated glass-ceramics GCB2.

[0052] The Bi 3+ doped blue light glass-ceramics prepared in Examples 2-4 and the undoped blank glass-ceramics prepared in Comparative Example 1 were subjected to spectral performance analysis, and the results are shown in Figure 3 From the results, it can be seen that the transmittance of the Bi 3+ doped blue light glass-ceramics prepared in Examples 2-4 in the range of 450-800 nm was as high as 80%, compared with the undoped glass-ceramics (Comparative Example 1, the transmittance in the range of 450-800 nm was as high as 80%, and the sample was tested for luminescent performance, and no fluorescence was detected), and the Bi 3+ doped glass-ceramics slightly shifted the transmittance spectrum curve to the long wavelength direction, which was caused by the Bi 3+ : 1 S0→ 3 P1 absorption transition.

[0053] The base glass block (GB0.6) obtained in Example 2 and the Bi 3+ doped blue light glass-ceramics (GCB0.6) were subjected to spectral performance testing using a fluorescence spectrometer with a xenon lamp as the excitation light source, and the results are shown in Figure 4 The base glass block GB0.6 and the Bi 3+ doped blue light glass-ceramics GCB0.6 were excited with 325 nm light, and Bi3+ The blue light exhibits broadband emission, with the strongest emission peaks located at 480 and 460 nm. Monitoring the corresponding emission peaks revealed an excitation spectrum exhibiting Bi0.05 in the 275–375 nm range. 3+ Typical excitation peaks, with optimal excitation wavelengths at 331 and 325 nm, corresponding to Bi 3+ : 1 S0→ 3 P1 transition. Bi 3+ The Stokes displacement in the microcrystalline glass is smaller than that in the glass sample, which may be related to Bi. 3+ Substitution of La in Ba4La6O(SiO4)6 lattice 3+ This is related to the priority of occupying the 4f lattice position of the 9-coordinate system.

[0054] The microcrystalline glass sample GCB0.6 obtained in Example 2 exhibits tunable luminescence. For example... Figure 5 As shown, as the excitation wavelength increases from 295 nm to 355 nm, the emission wavelength redshifts from 440 nm to 478 nm.

[0055] Using a xenon lamp as the excitation source, the spectral properties of the microcrystalline glass samples obtained in Examples 2-5 were tested using a fluorescence spectrometer. The results are as follows: Figure 6 As shown. The microcrystalline glass sample Bi was excited with 325 nm light. 3+ Bi can be observed in the doped blue light-emitting glass-ceramic in the range of 375–725 nm. 3+ Broadband blue light emission, with the strongest emission peak at 460 nm. Monitoring the corresponding emission peak, the measured excitation spectrum showed Bi0.05 in the 275–375 nm range. 3+ Typical excitation peaks, with optimal excitation wavelengths located at 325 nm, corresponding to Bi 3+ : 1 S0→ 3 P1 transition. Bi 3+ The Stokes displacement in the microcrystalline glass is smaller than that in the glass sample, which may be related to Bi. 3+ Substitution of La in Ba4La6O(SiO4)6 lattice 3+ This is related to the priority of occupying the 4f lattice position of the 9-coordinate system.

Claims

1. A Bi 3+ Doped blue light-emitting microcrystalline glass, characterized in that, Bi 3+ The doped blue light-emitting glass-ceramic has the following composition: SiO2-BaO-SrO-Al2O3-B2O3-La2O3-P2O5-Bi2O3. The molar percentages of each component are as follows: SiO2: 25~45%, SrO: 5~50%, BaO: 5~50%, B2O3: 5~20%, La2O3: 2~8%, Al2O3: 1~8%, P2O5: 2~10%, Bi2O3: 0.1~2.5%. Among them, Bi 3+ P2O5 acts as an activator and a nucleating agent. When the blue light-emitting microcrystalline glass is excited by ultraviolet light with a wavelength of 275-375nm, it emits blue light in a broadband range of 375-725nm, with the strongest emission peak located at 460nm; and as the excitation wavelength increases from 295nm to 355nm, the emission wavelength of the blue light-emitting microcrystalline glass redshifts from 440nm to 478nm.

2. The Bi according to claim 1 3+ Doped blue light-emitting microcrystalline glass, characterized in that, The Bi 3+ The crystal phase of the doped blue light microcrystalline glass is pure phase oxyapatite Ba4La6O(SiO4)6, and the grain size is 20~30 nm.

3. A Bi as described in claim 1 or 2 3+ A method for preparing doped blue light-emitting microcrystalline glass, characterized in that, Includes the following steps: (1) According to Bi 3+ Weigh the corresponding raw materials according to the proportion of each component of the doped blue light microcrystalline glass and mix them evenly. Place them in a crucible and keep them in a high-temperature furnace at 1400~1500℃ for 1~4 hours. Place the homogenized melt on a preheated mold to form it, and then transfer it to a muffle furnace at 580~650℃ for annealing. After annealing, cool it to room temperature with the furnace to obtain the base glass block. (2) The base glass block from step (1) is placed in a muffle furnace and heated to 720-850°C at a rate of 10-20 K / min, and held at that temperature for 4-48 hours. After that, it is cooled to room temperature with the furnace to obtain Bi. 3+ Doped blue light microcrystalline glass.

4. The Bi according to claim 3 3+ A method for preparing doped blue light-emitting microcrystalline glass, characterized in that, In step (1), SrO and BaO are introduced in the form of carbonates, B2O3 is introduced in the form of boric acid, P2O5 is introduced in the form of ammonium dihydrogen phosphate, and the bismuth element in Bi2O3 is introduced in the form of a bismuth source, wherein the bismuth source is selected from bismuth-containing oxides and / or bismuth salts, and SiO2, Al2O3 and La2O3 are introduced in the form of oxides.

5. The Bi according to claim 3 3+ A method for preparing doped blue light-emitting microcrystalline glass, characterized in that, The term "mixed evenly" refers to grinding and stirring the mixture in an agate mortar until it is uniform.

6. The Bi according to claim 3 3+ A method for preparing doped blue light-emitting microcrystalline glass, characterized in that, The mold preheated in step (1) is a brass mold preheated to 150~220℃.

7. The Bi according to claim 3 3+ A method for preparing doped blue light-emitting microcrystalline glass, characterized in that, The annealing time in step (1) is 1 to 3 hours.

8. A Bi as described in claim 1 or 2 3+ Application of doped blue light-emitting microcrystalline glass in near-ultraviolet light-excited white LEDs.

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