Ba3Yb (PO4) 3 crystalline phase glass ceramic, preparation method thereof, luminescent material and application of Ba3Yb (PO4) 3 crystalline phase glass ceramic

Abstract

The invention belongs to the technical field of luminescent materials, and particularly relates to Ba3Yb (PO4) 3 crystalline phase glass ceramic, a preparation method thereof, a luminescent material and application. The Ba3Yb (PO4) 3 crystal phase glass ceramic is prepared from the following raw materials in percentage by mole: 25%-30% of BaCO3, 38%-42% of SiO2, 25%-40% of H3BO3, 3%-6% of P2O5 and 2%-5% of Yb2O3, totaling 100%. The preparation method comprises the following steps: designing a glass ceramic formula, and preparing a precursor glass matrix by adopting a high-temperature melting method; the precursor glass matrix is subjected to crystallization heat treatment to induce Ba3Yb (PO4) 3 crystal phases to be precipitated in situ and uniformly distributed in the precursor glass matrix, so that the preparation of the block transparent glass ceramic material is realized, and the block transparent glass ceramic material has high luminous efficiency of fluorescent powder and mechanical strength of glass.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of luminescent materials, and particularly relates to a Ba3Yb(PO4)3 crystal phase glass ceramic, a preparation method thereof, a luminescent material and application. BACKGROUND

[0002] Upconversion luminescent materials can convert low-energy near-infrared light into high-energy visible light, and have wide application prospects in the fields of solid-state lasers, biological imaging and light-emitting diodes. Orthophosphates have become a research hotspot of luminescent materials due to their stable crystal structure and excellent luminescent performance. Among them, Ba3Yb(PO4)3, as a typical elpasolite-type phosphate, has a unique skeleton-type structure characteristic. Yb 3+ occupies the 16c site, and has the same charge, the same coordination number and extremely close ionic radius as common luminescent ions such as Tm 3+ , Er 3+ and Ho 3+ , thus having extremely high structural compatibility. This makes the doping ions preferentially replace Yb 3+ , ensuring the stability of the crystal structure after doping. At the same time, Yb 3+ as an intrinsic component of the Ba3Yb(PO4)3 matrix can directly act as a sensitizer of the luminescent center, efficiently absorb near-infrared light and transfer energy, and enhance the upconversion luminescent intensity of the luminescent center.

[0003] At present, the research on Ba3Yb(PO4)3 materials mainly focuses on chemical synthesis methods such as high-temperature solid-phase method, and through doping thulium, erbium or holmium or co-doping thulium / erbium / holmium, powder fluorescent materials are prepared. Although upconversion luminescence can be achieved through doping, such powder fluorescent materials have obvious defects in actual application: the fluorescent powder particles need to be coated and packaged with the help of organic adhesives. When mixed with organic adhesives, sedimentation easily occurs due to the density difference, resulting in uneven color temperature and light color distribution between different areas of the LED device, or even in the same device, which seriously affects the consistency of optical performance. Moreover, the organic adhesives are prone to aging, yellowing and even falling off after long-term use, leading to the degradation of the luminescent performance and the decline of the stability of the LED device, which limits its long-term reliability and service life. SUMMARY

[0004] In order to solve the technical problems that the Ba3Yb(PO4)3 powder fluorescent material in the prior art needs to be coated and packaged by means of an organic binder, particle settlement is prone to occur, resulting in poor optical uniformity of the prepared LED device, and the organic binder is prone to aging, thereby limiting the reliability and service life of the LED device, the present application provides a Ba3Yb(PO4)3 crystal phase glass ceramic and a preparation method, a luminescent material and an application thereof. The present application designs a glass ceramic formula, and a precursor glass matrix is prepared by a high-temperature melting method; and the precursor glass matrix is subjected to crystallization heat treatment to induce Ba3Yb(PO4)3 crystal phase to precipitate in situ and uniformly distribute in the precursor glass matrix, so that a uniform bulk transparent glass ceramic material is prepared, the optical properties of the glass ceramic material itself are highly consistent, and excellent color uniformity of the final LED product is ensured. Meanwhile, the glass ceramic has excellent high-temperature resistance and stable structure, and the long-term stability of the LED device is significantly improved.

[0005] The Ba3Yb(PO4)3 crystal phase glass ceramic prepared in the present application has high luminescent efficiency of the fluorescent powder and mechanical strength of the glass.

[0006] The first object of the present application is to provide a preparation method of a Ba3Yb(PO4)3 crystal phase glass ceramic, comprising the following steps: The Ba3Yb(PO4)3 crystal phase glass ceramic is prepared from the following raw materials in terms of mole percentage: BaCO3 25%-30%, SiO2 38%-42%, H3BO3 25%-40%, P2O5 3%-6% and Yb2O3 2%-5%, and the total is 100%; the raw materials are melted, solidified and formed, and annealed to obtain a precursor glass matrix according to the raw material ratio of the Ba3Yb(PO4)3 crystal phase glass ceramic; the precursor glass matrix is subjected to crystallization heat treatment to induce Ba3Yb(PO4)3 nanocrystals to precipitate in situ from the precursor glass matrix, and the Ba3Yb(PO4)3 crystal phase glass ceramic is obtained; the temperature of the crystallization heat treatment is 780-810 DEG C.

[0007] Preferably, the Ba3Yb(PO4)3 crystal phase glass ceramic is prepared from the following raw materials in terms of mole percentage: BaCO3 27%, SiO2 40%, H3BO3 28%, P2O5 3% and Yb2O3 2%, and the total is 100%.

[0008] Preferably, the temperature of the crystallization heat treatment is 780 DEG C. When the temperature of the crystallization heat treatment is lower than 780 DEG C, the Ba3Yb(PO4)3 crystal phase cannot be precipitated in the glass matrix; when the temperature of the crystallization heat treatment is high, although the Ba3Yb(PO4)3 crystal phase is precipitated, the Ba3Yb(PO4)3 crystal phase will appear agglomeration phenomenon, light scattering is serious, and the luminescent efficiency of the glass ceramic is reduced.

[0009] Preferably, the temperature rising rate of the crystallization heat treatment is 5-10℃ / min, and the holding time is 1-3h.

[0010] Preferably, the melting temperature is 1400-1500℃, and the time is 1-2h.

[0011] Preferably, the annealing temperature is 450-500℃, and the time is 1-4h.

[0012] The second object of the present application is to provide a Ba3Yb(PO4)3 crystal phase glass ceramic prepared by the above preparation method.

[0013] Preferably, the grain size of the Ba3Yb(PO4)3 crystal phase glass ceramic is not more than 100nm.

[0014] Preferably, the transmittance of the Ba3Yb(PO4)3 crystal phase glass ceramic in the visible light region is more than 70%.

[0015] The third object of the present application is to provide a luminescent material prepared by doping a rare earth element in a Ba3Yb(PO4)3 crystal phase glass ceramic matrix.

[0016] Preferably, the rare earth element is at least one of thulium, erbium and holmium.

[0017] Preferably, the specific preparation method of the luminescent material is as follows: In terms of mole percentage, BaCO3 25-30%, SiO2 38-42%, H3BO3 25-40%, P2O5 3-6%, Yb2O3 2-5% and a rare earth element source 0.2-0.5%, totaling 100%; the raw materials are melted, solidified and formed and annealed to obtain a precursor glass matrix; the precursor glass matrix is subjected to a crystallization heat treatment to induce Ba3Yb(PO4)3 nanocrystals to be in-situ precipitated from the precursor glass matrix to obtain the luminescent material; and the rare earth element source is at least one of Er2O3, Tm2O3 and Ho2O3.

[0018] The fourth object of the present application is to provide an application of the luminescent material in the preparation of a luminescent device.

[0019] Compared with the prior art, the present application has the following technical effects: The Ba3Yb(PO4)3 crystal phase glass ceramic of the present application is prepared from the following raw materials in terms of mole percentage: BaCO3 25%-30%, SiO2 38%-42%, H3BO3 25%-40%, P2O5 3%-6%, and Yb2O3 2%-5%, totaling 100%. According to the raw material ratio of the Ba3Yb(PO4)3 crystal phase glass ceramic, a precursor glass matrix with a stable glass network structure is prepared; by growing Ba3Yb(PO4)3 crystal particles uniformly distributed in the precursor glass matrix in situ, a uniform bulk transparent glass ceramic is prepared, so that the optical properties of the glass ceramic material itself are highly consistent, ensuring excellent color uniformity of the final LED product. At the same time, the glass ceramic material has excellent high-temperature resistance and stable structure, significantly improving the long-term stability of the LED device. The problem of uneven color temperature and light color distribution caused by sedimentation of the powder material is avoided, ensuring excellent color uniformity of the device.

[0020] The Ba3Yb(PO4)3 crystal phase glass ceramic of the present application is a bulk body with good mechanical strength, does not need to be coated and packaged with adhesives such as resin, and can be directly processed such as cutting and polishing to adapt to different device shapes, simplifying the process flow. Moreover, the glass ceramic material has a stable structure, prolonging the service life and reliability of the light-emitting device.

[0021] The present application uses 980nm light as an excitation source to convert into visible light for illumination, which not only helps to reduce energy consumption, but also improves the efficiency and service life of the lighting equipment. By 980nm light excitation, warm white light or other visible light is emitted, and high-energy blue light is eliminated from the light source itself, which is expected to achieve truly "blue light hazard-free" healthy lighting, especially suitable for night lighting and children's places. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 X-ray diffraction spectrum of the Ba3Yb(PO4)3 crystal phase glass ceramic prepared in Example 1.

[0023] Figure 2 Er 3+ Upconversion emission spectrum of the Ba3Yb(PO4)3 crystal phase glass ceramic doped with Er

[0024] Figure 3 Tm 3+ Upconversion emission spectrum of the Ba3Yb(PO4)3 crystal phase glass ceramic doped with Tm

[0025] Figure 4 Er 3+ Light transmittance of the Ba3Yb(PO4)3 crystal phase glass ceramic doped with Er

[0026] Figure 5 Scanning electron microscope photograph of Ba3Yb(PO4)3 crystalline glass ceramic prepared in Example 1.

[0027] Figure 6 Scanning electron microscope photograph of Ba3Yb(PO4)3 crystalline glass ceramic prepared in Example 2. DETAILED DESCRIPTION

[0028] In order to make the skilled in the art better understand the technical solutions of the present application can be implemented, the following specific examples of the present application is further described.

[0029] In the description of the present application, if not special, the reagents used are commercially available, the methods used are conventional techniques in the art.

[0030] Example 1 A method for preparing a Ba3Yb(PO4)3 crystalline glass ceramic, comprising the following steps: According to the mole percentage, 27% BaCO3, 40% SiO2, 28% BO3, 3% P2O5 and 2% Yb2O3 are mixed uniformly, placed in a corundum crucible, put into a silicon molybdenum furnace, heated to 1100℃, and kept for 1 hour; continue to heat to 1400℃, and keep for 1 hour, then melt the raw materials into a liquid state to obtain a molten liquid. Pour the molten liquid in the crucible on the preheated stainless steel mold to solidify and form, quickly put it into a 450℃ muffle furnace to anneal, keep for 2 hours, and then reduce to room temperature with the furnace, to prepare a precursor glass matrix.

[0031] Put the precursor glass matrix into a box-type resistance furnace, use one-step crystallization method, heat to 780℃ at a rate of 5℃ / min, keep for 3 hours, to obtain a Ba3Yb(PO4)3 crystalline glass ceramic.

[0032] Example 2 A method for preparing a Ba3Yb(PO4)3 crystalline glass ceramic, comprising the following steps: According to the mole percentage, 27% BaCO3, 40% SiO2, 28% BO3, 3% P2O5 and 2% Yb2O3 are mixed uniformly, placed in a corundum crucible, put into a silicon molybdenum furnace, heated to 1100℃, and kept for 1 hour; continue to heat to 1400℃, and keep for 1 hour, then melt the raw materials into a liquid state to obtain a molten liquid. Pour the molten liquid in the crucible on the preheated stainless steel mold to solidify and form, quickly put it into a 450℃ muffle furnace to anneal, keep for 2 hours, and then reduce to room temperature with the furnace, to prepare a precursor glass matrix.

[0033] The precursor glass matrix is placed into a box-type resistance furnace, a one-step crystallization method is adopted, and the temperature is raised to 800℃ at a temperature raising rate of 5℃ / min, and the temperature is kept for 3 hours, so as to obtain Ba3Yb(PO4)3 crystal phase glass ceramic.

[0034] Application Example 1 An Er 3+ A preparation method of the doped Ba3Yb(PO4)3 crystal phase glass ceramic comprises the following steps: According to the molar percentage, 27% BaCO3, 40% SiO2, 27.5% H3BO3, 3% P2O5, 2% Yb2O3 and 0.5% Er2O3 are uniformly mixed, placed in a corundum crucible, placed into a silicon molybdenum furnace, and heated to 1100℃, and kept for 1 hour; the temperature is continuously raised to 1400℃, and kept for 1 hour, so that the raw materials are melted into a liquid state to obtain a molten liquid. The molten liquid in the crucible is poured onto a preheated stainless steel mold to solidify and form, quickly placed into a 450℃ muffle furnace for annealing, kept for 2 hours, and the furnace is cooled to room temperature, so as to obtain the precursor glass matrix.

[0035] The precursor glass matrix is placed into a box-type resistance furnace, a one-step crystallization method is adopted, and the temperature is raised to 780℃ at a temperature raising rate of 5℃ / min, and the temperature is kept for 3 hours, so as to obtain Er 3+ The doped Ba3Yb(PO4)3 crystal phase glass ceramic is used as a luminescent material.

[0036] Application Example 2 A Tm 3+ A preparation method of the doped Ba3Yb(PO4)3 crystal phase glass ceramic comprises the following steps: According to the molar percentage, 27% BaCO3, 40% SiO2, 27.8% H3BO3, 3% P2O5, 2% Yb2O3 and 0.2% Tm2O3 are uniformly mixed, placed in a corundum crucible, placed into a silicon molybdenum furnace, and heated to 1100℃, and kept for 1 hour; the temperature is continuously raised to 1400℃, and kept for 1 hour, so that the raw materials are melted into a liquid state to obtain a molten liquid. The molten liquid in the crucible is poured onto a preheated stainless steel mold to solidify and form, quickly placed into a 450℃ muffle furnace for annealing, kept for 2 hours, and the furnace is cooled to room temperature, so as to obtain the precursor glass matrix.

[0037] The precursor glass matrix is placed into a box-type resistance furnace, a one-step crystallization method is adopted, and the temperature is raised to 780℃ at a temperature raising rate of 5℃ / min, and the temperature is kept for 3 hours, so as to obtain Tm 3+ The doped Ba3Yb(PO4)3 crystal phase glass ceramic is used as a luminescent material.

[0038] Further, the Er 3+ / Tm 3+Co-doped in Ba3Yb(PO4)3 nanocrystal glass ceramics, and adjust the doping ratio of rare earth ions Er 3+ / Tm 3+ , or adjust the pump light source power, is expected to make white light emitting LED device, white light display.

[0039] Experimental test: The Ba3Yb(PO4)3 crystal phase glass ceramic prepared in example 1~example 2 is cut, and then double side grinding, polishing, to obtain the thickness of 2mm glass ceramic sample. The main crystal phase of Ba3Yb(PO4)3 crystal phase glass ceramic is determined by X-ray diffraction analysis; the microstructure of glass ceramic is observed by scanning electron microscope; the light transmittance of Er 3+ doped Ba3Yb(PO4)3 crystal phase glass ceramic with thickness of 2mm is measured by ultraviolet-visible-near infrared spectrophotometer; the upconversion luminescence spectrum of erbium or thulium doped Ba3Yb(PO4)3 crystal phase glass ceramic is measured by fluorescence spectrometer.

[0040] As Figure 1 shown, the XRD diffraction pattern is compared with the standard card, and the crystal phase precipitated in the glass matrix is Ba3Yb(PO4)3 (JCPDS #00-043-0211), which shows that the crystal phase of Ba3Yb(PO4)3 crystal phase glass ceramic is Ba3Yb(PO4)3.

[0041] The upconversion emission spectrum of Er 3+ doped, Tm 3+ doped Ba3Yb(PO4)3 crystal phase glass ceramic and precursor glass is measured by fluorescence spectrometer, under the excitation of 980nm semiconductor laser, the upconversion emission spectrum of Er 3+ doped Ba3Yb(PO4)3 crystal phase glass ceramic is shown in Figure 2 , the sample appears three spectral bands between 400nm and 700nm, which are blue spectral band of 470nm~490nm, green spectral band of 520nm~565nm and red spectral band of 640nm~680nm. The green spectral band has two strongest peaks, which are 527nm and 550nm, corresponding to the transition of Er 3+ 2 H 11 / 2 → 4 I 15 / 2 and 4 S 3 / 2 → 4 I 15 / 2 ; the strongest peak of red spectral band is 655nm, corresponding to the transition of Er 3+ 4 F 9 / 2 → 4 I​​15 / 2 Transition; and the luminescence intensity of the glass-ceramic sample is obviously higher than that of the precursor glass sample. In addition, when the transmittance of the sample is low, the light emitted by the luminescence center is absorbed or scattered by the material in large amount.

[0042] Under the excitation of a 980 nm semiconductor laser, the Tm 3+ The up-conversion emission spectrum of the Ba3Yb(PO4)3 nanocrystal glass-ceramic doped with Tm is shown in Figure 3 The spectral band of the sample between 450 nm and 500 nm is a blue spectral band.

[0043] As shown in Figure 4 Fig. 1, the Er 3+ The light transmittance of the Ba3Yb(PO4)3 crystal phase glass-ceramic doped with Tm can reach 75% in the visible light region.

[0044] As shown in Figure 5 Fig. 4, the Ba3Yb(PO4)3 crystal phase glass-ceramic prepared in Example 1 has a uniform grain distribution, and the grain size is about 100 nm.

[0045] As shown in Figure 6 Fig. 5, the Ba3Yb(PO4)3 crystal phase glass-ceramic prepared in Example 2 has the Ba3Yb(PO4)3 crystal phase precipitated, but the crystal phase has a clustering phenomenon, and the light scattering is serious, resulting in a reduced luminescence efficiency.

[0046] It should be noted that when the numerical range is involved in the present application, both endpoints of each numerical range and any number between the two endpoints can be selected. Since the same steps and examples are adopted, the preferred examples are described in the present application in order to prevent redundancy. Although the preferred examples of the present application have been described, those skilled in the art can make additional changes and modifications to the examples once the basic creative concept is known, and these changes and modifications all fall within the scope of the present application.

[0047] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. If these modifications and variations of the present application fall within the scope of the equivalent technology of the present application, the present application also intends to include these modifications and variations.

Claims

1. A method for preparing Ba3Yb(PO4)3 crystalline phase glass-ceramics, characterized in that, Includes the following steps: According to molar percentage, Ba3Yb(PO4)3 crystalline glass-ceramics are made from the following raw materials: BaCO3 25%–30%, SiO2 38%–42%, H3BO3 25%–40%, P2O5 3%–6%, and Yb2O3 2%–5%, totaling 100%; According to the raw material ratio of Ba3Yb(PO4)3 crystalline glass ceramic, the raw materials are melted, solidified and annealed to obtain the precursor glass matrix; The precursor glass matrix was subjected to crystallization heat treatment to induce the in-situ precipitation of Ba3Yb(PO4)3 nanocrystals from the precursor glass matrix, thus obtaining Ba3Yb(PO4)3 crystalline phase glass ceramic. The temperature for crystallization heat treatment is 780℃~810℃.

2. The method for preparing Ba3Yb(PO4)3 crystalline glass-ceramic according to claim 1, characterized in that, According to molar percentage, Ba3Yb(PO4)3 crystalline glass-ceramics are made from the following raw materials: BaCO3 27%, SiO2 40%, H3BO3 28%, P2O5 3%, and Yb2O3 2%, totaling 100%.

3. The method for preparing Ba3Yb(PO4)3 crystalline glass-ceramic according to claim 1, characterized in that, The melting temperature is 1400℃~1500℃; the annealing temperature is 450℃~500℃.

4. A Ba3Yb(PO4)3 crystalline phase glass-ceramic, characterized in that, The Ba3Yb(PO4)3 crystalline glass-ceramic is prepared by the method described in any one of claims 1 to 3.

5. The Ba3Yb(PO4)3 crystalline glass-ceramic according to claim 4, characterized in that, The grain size of Ba3Yb(PO4)3 crystalline phase glass ceramics is no greater than 100nm.

6. The Ba3Yb(PO4)3 crystalline glass-ceramic according to claim 4, characterized in that, Ba3Yb(PO4)3 crystalline glass-ceramics have a transmittance of more than 70% in the visible light region.

7. A luminescent material, characterized in that, The luminescent material is prepared by doping rare earth elements into a Ba3Yb(PO4)3 crystalline glass-ceramic matrix; the Ba3Yb(PO4)3 crystalline glass-ceramic is the Ba3Yb(PO4)3 crystalline glass-ceramic as described in claim 4.

8. The luminescent material according to claim 7, characterized in that, The rare earth element is at least one of thulium, erbium, and holmium.

9. The luminescent material according to claim 7, characterized in that, The specific preparation method of the luminescent material is as follows: Based on molar percentages, BaCO3 25%–30%, SiO2 38%–42%, H3BO3 25%–40%, P2O5 3%–6%, Yb2O3 2%–5%, and rare earth element source 0.2%–0.5%, totaling 100%; The raw materials are melted, solidified, and annealed to obtain the precursor glass matrix. The precursor glass matrix was subjected to crystallization heat treatment to induce the in-situ precipitation of Ba3Yb(PO4)3 nanocrystals from the precursor glass matrix to obtain the luminescent material. The rare earth element source is at least one of Er2O3, Tm2O3 and Ho2O3.

10. The application of a luminescent material in the fabrication of a light-emitting device, characterized in that, The luminescent material is the luminescent material as described in claim 7.

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