Upconversion luminescence glass-ceramics and preparation method and device thereof

Abstract

The application discloses up-conversion luminescence glass-ceramics and a preparation method and device thereof. The up-conversion luminescence glass-ceramics comprises 40-80 mole parts of TeO2, 10-40 mole parts of ZnO, 5-60 mole parts of GeO2, 0.01-5 mole parts of ErF3, 3-15 mole parts of PbF2 and 0.01-10 mole parts of Li2CO3. The up-conversion luminescence glass-ceramics can generate red light with high brightness and high purity under the excitation of near-infrared long-wave 1550nm laser, and has high luminous efficiency, and has wide application prospects in the fields of three-dimensional display, optical data storage, optical switch, solar cell and the like.

Description

Technical Field

[0001] This invention belongs to the field of optics, and more specifically, relates to upconversion luminescent microcrystalline glass and its preparation method and apparatus. Background Technology

[0002] Upconversion luminescent materials can emit visible light, and even ultraviolet light, under long-wavelength (such as infrared) radiation excitation, which is an anti-Stokes process. Rare-earth ion-doped luminescent materials have the advantages of excellent luminescence stability, significant peak positions, and long fluorescence lifetimes, and have broad application prospects in fields such as three-dimensional displays, optical data storage, optical switches, and solar cells. Summary of the Invention

[0003] This invention is primarily based on the following problems and findings:

[0004] Er 3+ Due to its abundant 4f-4f transition energy levels, it is considered the most ideal near-infrared upconversion luminescent ion and has been extensively studied by researchers. Currently, in Er... 3+ In doped glass-ceramics, research often focuses on upconversion emission of green and red light using near-infrared short-wave excitation such as 808nm and 980nm. For example, Er... 3+ Single-doped TeO2-TiO2-ZnO glass exhibits strong green upconversion luminescence under excitation at 808 nm and 975 nm, corresponding to... 2 H 11 / 2 , 4 S 3 / 2 → 4 I 15 / 2 Transition, and the corresponding 4 F 9 / 2 → 4 I 15 / 2 The weaker red emission during the transition; for example, there are reports of Er in aluminosilicate glasses prepared by laser levitation zone technology through directional solidification. 3+ The spectral properties and upconversion from near-infrared to visible light can be observed under 800 nm excitation. 2 H 11 / 2 → 4 I 15 / 2 and 4 S 3 / 2 → 4 I 15 / 2 Transitions, green upconversion emission induced by two-photon processes at 525 nm and 550 nm; and, for example, the preparation of TeO2-PbCl2-WO3:Er by melt quenching method has been disclosed. 3+Glass, under 980 nm excitation, exhibits strong infrared-visible upconversion luminescence. The green, red, and near-infrared upconversion 4f-4f emission bands observed at 530, 550, 660, and 850 nm are attributed to two-photon absorption processes. However, the above-mentioned effects on Er... 3+ The excitation source used for ion upconversion luminescence is generally near-infrared lasers such as 808nm and 980nm, and there is very little research on luminescence using 1550nm excitation.

[0005] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, one objective of this invention is to propose an upconversion luminescent microcrystalline glass, its preparation method, and its luminescence. This upconversion luminescent microcrystalline glass can generate high-brightness and high-purity red light under excitation by a near-infrared long-wavelength 1550nm laser, exhibiting high luminous efficiency and showing broad application prospects in fields such as three-dimensional displays, optical data storage, optical switches, and solar cells.

[0006] In one aspect of the invention, an upconversion luminescent glass-ceramic is provided. According to an embodiment of the invention, the glass-ceramic comprises: 40 to 80 mol parts of TeO2, 10 to 40 mol parts of ZnO, 5 to 60 mol parts of GeO2, 0.01 to 5 mol parts of ErF3, 3 to 15 mol parts of PbF2, and 0.01 to 10 mol parts of Li2CO3.

[0007] The upconversion luminescent glass crystal according to the above embodiments of the present invention has at least the following beneficial effects: 1) the telluride germanate glass crystal prepared using TeO2 and GeO2 as network forging bodies has lower phonon energy, which can effectively improve the luminescence efficiency of the luminescent center; 2) by simultaneously introducing rare earth ions Er into the glass crystal... 3+ Together with PbF2, they can form microcrystals that promote the absorption of 1550nm photons, thus increasing the Er in the glass-ceramic. 3+ It can be excited by a near-infrared long-wavelength 1550nm laser, by 4 F 9 / 2 Energy level radiative transition to 4 I 15 / 2 This technology enables the emission of 660nm red light at specific energy levels, while also improving the purity of the red light emission. Furthermore, PbF2 has low phonon energy; introducing PbF2 into tellurium germanate glass crystals can reduce Er... 3+ The probability of multiphonon-assisted nonradiative transitions between energy levels is reduced, decreasing Er 3+The symmetry of the surrounding area is beneficial to improving the upconversion luminescence efficiency of the glass-ceramic; 3) By adding Li2CO3, the oxygen provided by Li2CO3 can increase the amount of oxygen in the glass-ceramic, causing some of the original tellurium-oxygen bonds to break, forming non-bridging oxygen, destroying the three-dimensional structure. At the same time, due to the symmetry of the surrounding area, the oxygen provided by Li2CO3 can increase the amount of oxygen in the glass-ceramic, causing some of the original tellurium-oxygen bonds to break, forming non-bridging oxygen, destroying the three-dimensional structure. + Its small ionic radius allows it to enter the [TeO4] bitrigonal pyramid, [TeO3] and [TeO3] ions. +1 The gaps between the triangular pyramids, which form the basic structural units, facilitate movement, thereby helping to lower the firing temperature of the glass-ceramic, reducing the difficulty of preparation and processing costs. In summary, the upconversion luminescent glass-ceramic according to the above embodiments of the present invention can generate high-brightness and high-purity red light under excitation by a near-infrared long-wavelength 1550nm laser, exhibiting high luminous efficiency. It has broad application prospects in fields such as three-dimensional displays, optical data storage, optical switches, and solar cells.

[0008] In addition, the upconversion luminescent microcrystalline glass according to the above embodiments of the present invention may also have the following additional technical features:

[0009] In some embodiments of the present invention, the upconversion luminescent glass crystal comprises: 50 to 70 moles of the TeO2, 10 to 30 moles of the ZnO, 5 to 30 moles of the GeO2, 0.01 to 3 moles of the ErF3, 5 to 10 moles of the PbF2, and 1 to 5 moles of the Li2CO3.

[0010] In some embodiments of the present invention, the molar ratio of TeO2 to GeO2 is (4-7):1.

[0011] In another aspect of the present invention, a method for preparing the above-mentioned upconversion luminescent glass-ceramic is provided. According to an embodiment of the present invention, the method includes: (1) mixing TeO2, ZnO, GeO2, ErF3, PbF2, and Li2CO3 in a certain proportion and drying them to obtain a mixed raw material; (2) melting the mixed raw material in an air atmosphere to obtain a mixed glass melt; and (3) shaping the mixed glass melt to obtain an upconversion luminescent glass-ceramic. This method is not only simple and easy to implement for large-scale industrial production, but the obtained upconversion luminescent glass-ceramic can generate red light with high brightness and purity under the excitation of near-infrared long-wavelength 1550nm laser, and has high luminous efficiency, which has broad application prospects in the fields of three-dimensional display, optical data storage, optical switches, and solar cells.

[0012] In some embodiments of the present invention, step (1) includes grinding and mixing.

[0013] In some embodiments of the present invention, in step (1), the mixing process is carried out in an agate mortar.

[0014] In some embodiments of the present invention, in step (1), the drying temperature is 100℃~400℃ and the time is 1h~5h.

[0015] In some embodiments of the present invention, in step (2), the melting process is carried out at a temperature of 800°C to 1100°C for a time of 10 min to 80 min.

[0016] In some embodiments of the invention, the melting process is carried out in a platinum crucible.

[0017] In some embodiments of the present invention, step (3) includes the molding process of pouring the molten glass into a mold, annealing it at 240°C to 310°C for 2 to 6 hours, and then performing microcrystallization at 330°C to 410°C.

[0018] In another aspect, the present invention provides an apparatus comprising the aforementioned upconversion luminescent microcrystalline glass, or an upconversion luminescent microcrystalline glass prepared by the aforementioned method. This apparatus possesses all the features and effects of the aforementioned upconversion luminescent microcrystalline glass and the aforementioned method, which will not be elaborated further here. In general, this apparatus can generate red light with high brightness and purity under excitation by a near-infrared long-wavelength 1550nm laser, exhibiting high luminous efficiency.

[0019] In some embodiments of the present invention, the laser wavelength used to excite the upconversion luminescent microcrystalline glass to emit light is 1550 nm.

[0020] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0022] Figure 1 This is a flowchart of the preparation of upconversion luminescent glass crystal according to an embodiment of the present invention;

[0023] Figure 2 The emission spectra of the microcrystalline glass of Examples 1-4 and Comparative Examples 1-3 according to the present invention under laser excitation at a wavelength of 1550 nm are shown.

[0024] Figure 3 This is a light-emitting image displayed within the microcrystalline glass body according to Embodiment 1 of the present invention;

[0025] Figure 4 This is a light-emitting image displayed within the microcrystalline glass body according to Embodiment 2 of the present invention;

[0026] Figure 5 This is a light-emitting image displayed within the microcrystalline glass body according to Embodiment 3 of the present invention;

[0027] Figure 6 This is a light-emitting image displayed within the microcrystalline glass body according to Embodiment 4 of the present invention;

[0028] Figure 7 The image is a light-emitting image displayed within the microcrystalline glass body according to Comparative Example 2 of the present invention;

[0029] Figure 8 The image is a light-emitting image displayed within the microcrystalline glass body according to Comparative Example 3 of the present invention. Detailed Implementation

[0030] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0031] In one aspect of the present invention, an upconversion luminescent glass-ceramic is provided. According to an embodiment of the present invention, the upconversion luminescent glass-ceramic comprises: 40 to 80 mol parts of TeO2, 10 to 40 mol parts of ZnO, 5 to 60 mol parts of GeO2, 0.01 to 5 mol parts of ErF3, 3 to 15 mol parts of PbF2, and 0.01 to 10 mol parts of Li2CO3. Specifically, the content of TeO2 can be 45 mol parts, 55 mol parts, 65 mol parts, or 75 mol parts, etc.; the content of ZnO can be 15 mol parts, 20 mol parts, 25 mol parts, 30 mol parts, or 35 mol parts. The content of GeO2 can be 10 moles, 20 moles, 30 moles, 40 moles, or 50 moles, etc.; the content of ErF3 can be 0.05 moles, 0.1 moles, 1 mole, 2 moles, 3 moles, or 4 moles, etc.; the content of PbF2 can be 3.5 moles, 5 moles, 7 moles, 9 moles, 11 moles, 13 moles, or 14 moles, etc.; the content of Li2CO3 can be 0.05 moles, 0.1 moles, 0.5 moles, 1 mole, 3 moles, 5 moles, 7 moles, or 9 moles, etc.

[0032] According to the above embodiments of the present invention, the upconversion luminescent microcrystalline glass, by adding the above-mentioned amount of TeO2, forms a tellurate glass as the upconversion luminescent material matrix. It has low phonon energy, excellent chemical stability, low melting point and good rare earth solubility, which can effectively overcome the shortcomings of traditional silicate glass or phosphate glass, such as low rare earth doping luminescence efficiency. It is not only beneficial to improve the luminescence efficiency of the upconversion luminescent microcrystalline glass, but also beneficial to simplify the preparation process of the microcrystalline glass, and improve the solubility and dispersion of rare earth ions in the glass matrix. In addition, by adding the above-mentioned amount of metal oxides ZnO and GeO2 as network intermediates, it is not only beneficial to improve the thermal stability of the tellurate glass matrix, but also to improve the asymmetry around the ion luminescence center and improve the luminescence efficiency of the luminescence center. The inventors discovered that in the microcrystalline glass of the above embodiments of the present invention, if the relative content of TeO2 is too low, it is difficult to obtain a luminescent material based on tellurate glass. If the relative content of TeO2 is too high, it will limit the content of other components (such as ZnO, GeO2, etc.) and affect the thermal stability of the microcrystalline glass. If the relative content of ZnO and GeO2 is too low, it will not improve the thermal stability of the microcrystalline glass sufficiently. If the relative content of ZnO and GeO2 is too high, it will be difficult to form a stable tellurate glass. The present invention, by controlling the content of TeO2, ZnO and GeO2 within the above range, is beneficial to balance the luminous efficiency and thermal stability of the microcrystalline glass.

[0033] Furthermore, by simultaneously introducing rare earth ions Er into the glass-ceramic... 3+ Adding PbF2 can form microcrystals that promote the absorption of 1550nm photons, thereby achieving multiphoton upconversion red light emission and improving the purity of red light emission. By adding the aforementioned amount of PbF2, microcrystals that promote the absorption of 1550nm photons can be formed, increasing the Er content in the glass-ceramic. 3+ It can be excited by a near-infrared long-wavelength 1550nm laser, by 4 F 9 / 2 Energy level radiative transition to 4 I 15 / 2 This technology enables the emission of 660nm red light at specific energy levels, while also improving the purity of the red light emission. Furthermore, PbF2 has low phonon energy; introducing PbF2 into tellurium germanate glass crystals can reduce Er... 3+ The probability of multiphonon-assisted nonradiative transitions between energy levels is reduced, decreasing Er 3+ The symmetry of the surrounding area is beneficial to improving the upconversion luminescence efficiency of glass-ceramics.

[0034] The inventors discovered that in the microcrystalline glass of the above embodiments of the present invention, if the relative content of ErF3 is too low, the luminescence intensity of the microcrystalline glass under near-infrared long-wavelength 1550nm laser excitation will be low; if the relative content of ErF3 is too high, the Er in the microcrystalline glass will be high. 3+ The concentration is high, Er 3+ The interionic spacing is small, Er 3+ Energy transfer between components can easily occur, causing concentration quenching and affecting the luminous efficiency of the glass-ceramic. This invention, by controlling the ErF3 content in the glass-ceramic within the aforementioned range, facilitates the production of upconversion luminescent glass-ceramics with both high luminous efficiency and intensity. If the relative content of PbF2 is too low, it is difficult to obtain microcrystals that promote the absorption of 1550nm photons, easily affecting the intensity and purity of the red light emitted by the glass-ceramic. If the relative content of PbF2 is too high, it not only easily leads to a decrease in the transparency of the glass-ceramic, affecting its luminous effect, but may also affect the purity of the red light emitted by the glass-ceramic under near-infrared long-wavelength 1550nm laser excitation. This invention, by controlling the PbF2 content in the glass-ceramic within the aforementioned range, helps to balance the transparency and red light emission effect of the glass-ceramic.

[0035] According to some embodiments of the present invention, the microcrystalline glass may include: 50 to 70 molar parts of TeO2, 10 to 30 molar parts of ZnO, 5 to 30 molar parts of GeO2, 0.01 to 3 molar parts of ErF3, and 5 to 10 molar parts of PbF2. Specifically, the content of TeO2 can be 52 mol, 55 mol, 60 mol, 65 mol, or 68 mol, etc.; the content of ZnO can be 12 mol, 18 mol, 24 mol, or 28 mol, etc.; the content of GeO2 can be 6 mol, 12 mol, 18 mol, 24 mol, or 28 mol, etc.; the content of ErF3 can be 0.02 mol, 0.2 mol, 0.8 mol, 1.2 mol, 1.8 mol, 2.4 mol, or 2.8 mol, etc.; and the content of PbF2 can be 5.2 mol, 6 mol, 6.5 mol, 7 mol, 7.5 mol, 8 mol, 8.5 mol, 9 mol, or 9.5 mol, etc. This can further improve the luminous efficiency and red light stability of the glass-ceramic.

[0036] According to some embodiments of the present invention, in glass-ceramics, the molar ratio of TeO2 to GeO2 can be (4-7):1, for example, 4.5 / 1, 5 / 1, 5.5 / 1, 6 / 1 or 6.5 / 1, etc. The inventors have found that if the molar ratio of TeO2 to GeO2 is too low, the relative content of GeO2 is too high, which will increase the difficulty of firing glass-ceramics on the one hand, and affect the formation of tellurate glass on the other hand; if the molar ratio of TeO2 to GeO2 is too high, the relative content of GeO2 is too low, which will not be enough to improve the thermal stability and luminous efficiency of glass-ceramics. The present invention, by controlling the molar ratio of TeO2 to GeO2 within the above range, is beneficial to further improve the luminous efficiency of glass-ceramics while reducing the firing difficulty and processing stability of glass-ceramics.

[0037] In another aspect of the invention, a method for preparing the above-described upconversion luminescent microcrystalline glass is provided. According to embodiments of the invention, combined with... Figure 1 Understanding, the method includes:

[0038] S100: TeO2, ZnO, GeO2, ErF3, PbF2, and Li2CO3 are mixed and dried according to the specified ratio to obtain a mixed raw material.

[0039] According to some embodiments of the present invention, the above-mentioned components can be added to a mixing device in a specified ratio for grinding and mixing. Grinding is beneficial to improving the uniformity of the mixture. Furthermore, a solvent can be added after grinding to form a slurry, further improving the dispersion of the components. The present invention does not impose any particular limitation on the specific type of solvent used in the mixing process; those skilled in the art can choose flexibly according to actual conditions, such as ethanol. After the above-mentioned components are mixed uniformly, the mixed raw materials are dried. The drying temperature can be 100℃~400℃, and the time can be 1h~5h. This effectively removes impurities such as water vapor or hydroxyl groups from the mixture, which helps to ensure the purity and luminescence effect of the microcrystalline glass. It should be noted that the present invention does not impose any particular limitation on the mixing device used for the mixing process; for example, the mixing process can be carried out in an agate mortar.

[0040] S200: The mixed raw materials are melted in an air atmosphere to obtain a mixed glass melt.

[0041] According to an embodiment of the present invention, the mixed raw materials obtained in S100 are melted in an air atmosphere. The melting temperature can be 800°C to 1100°C and the time can be 10 min to 80 min, thereby allowing the components to be fully melted to obtain a mixed glass melt. It should be noted that there are no particular restrictions on the material of the specific melting device in the present invention. Those skilled in the art can choose flexibly according to the actual situation. For example, the melting process can be carried out in a platinum crucible.

[0042] S300: The mixed glass melt is shaped to obtain upconversion luminescent microcrystalline glass.

[0043] According to an embodiment of the present invention, the mixed glass liquid obtained in S200 is subjected to molding treatment. The specific method of molding treatment is not particularly limited in the present invention; those skilled in the art can choose flexibly according to the actual situation. For example, the above-mentioned glass liquid can be poured into a mold for cooling and molding, and then the molding material can be annealed at 240℃~310℃ for 2h~6h to eliminate internal stress in the molding material. The inventors have found that if the annealing temperature is too low, the elimination of internal stress is incomplete; if the annealing temperature is too high, the molded material is prone to softening, affecting the molding effect. Then, the annealed material is subjected to microcrystallization treatment at 330℃~410℃ to form lead fluoride vitrified microcrystals. The purpose of forming lead fluoride vitrified microcrystals has been described in detail in the foregoing section and will not be repeated here.

[0044] In summary, the method for preparing upconversion luminescent organic glass is not only simple and easy to implement for large-scale industrial production, but also produces upconversion luminescent microcrystalline glass that can generate high brightness and purity red light under the excitation of near-infrared long-wavelength 1550nm laser, with high luminous efficiency. It has broad application prospects in fields such as three-dimensional display, optical data storage, optical switches, and solar cells.

[0045] In another aspect, the present invention provides an apparatus comprising the aforementioned upconversion luminescent microcrystalline glass, or upconversion luminescent microcrystalline glass prepared by the aforementioned method. This apparatus can generate red light with high brightness and purity under excitation by a near-infrared long-wavelength 1550nm laser, exhibiting high luminous efficiency. It should be noted that the apparatus includes, but is not limited to: light-emitting devices, display devices, battery devices, switching devices, or products or equipment comprising at least one of the aforementioned devices, such as display substrates, displays, lasers, laser memories, optical switches, solar cell modules, solar cell packs, electrical devices powered by solar cell modules or solar cell packs, etc.

[0046] The embodiments of the present invention are described in detail below. These embodiments are exemplary and are only used to explain the present invention, and should not be construed as limiting the invention. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0047] Example 1

[0048] (1) Calculate the weight of each component according to the molar percentage of glass composition in Table 1, weigh each raw material component into an agate mortar, grind for 15 minutes, add appropriate ethanol and continue grinding for 15 minutes to ensure that the materials are fully mixed and dried.

[0049] (2) The above-mentioned uniformly mixed and dried material is placed into a covered platinum crucible and melted in a box furnace at 930°C for 50 minutes. A uniform, bubble-free glass melt is obtained.

[0050] (3) The above-mentioned glass liquid was poured into a preheated graphite mold to obtain transparent tellurium germanate glass. The glass was quickly transferred into a muffle furnace and kept at 280°C for 4 hours. After cooling to room temperature with the furnace, the glass sample was taken out. The muffle furnace was then heated to 390°C at a heating rate of 3°C / min and kept at 390°C for 2 hours to perform annealing and microcrystallization treatment to obtain upconversion luminescent microcrystalline glass.

[0051] Examples 2-4

[0052] The differences from Example 1 are shown in Table 1.

[0053] Comparative Examples 1-3

[0054] The differences from Example 1 are shown in Table 1.

[0055] Table 1 shows the content of each component in Examples 1-4 and Comparative Examples 1-3.

[0056]

[0057] Results and Discussion

[0058] Under the same conditions, the upconversion luminescent glass crystals prepared in Examples 1-4 and Comparative Examples 1-3 were ground and polished, and then tested with 1550nm laser excitation. The emission spectra are shown below. Figure 2 As shown, the light emission conditions displayed in Examples 1-4 and Comparative Examples 2-3 are as follows: Figures 3-8As shown, the upconversion luminescent microcrystalline glass of the above embodiments of this application can generate red light with high brightness and purity under the excitation of near-infrared long-wavelength 1550nm laser, and has high luminous efficiency. Specifically, in Comparative Example 1, without the addition of PbF2, it is almost impossible to emit red light under the excitation of near-infrared long-wavelength 1550nm laser; in Comparative Example 2, the PbF2 content is too low, resulting in insufficient intensity of red light emitted by the microcrystalline glass; in Comparative Example 2, the PbF2 content is too high, resulting in poor transparency of the microcrystalline glass, and the energy of the laser is easily absorbed or lost through scattering when passing through the microcrystalline glass. In summary, the upconversion luminescent microcrystalline glass of the above embodiments of the present invention can generate red light with high brightness and purity under the excitation of near-infrared long-wavelength 1550nm laser, and has broad application prospects in the fields of three-dimensional display, optical data storage, optical switches, and solar cells.

[0059] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0060] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An upconversion luminescent microcrystalline glass, characterized in that, include: The composition comprises 40 to 80 moles of TeO2, 10 to 40 moles of ZnO, 5 to 30 moles of GeO2, 0.01 to 5 moles of ErF3, 3 to 15 moles of PbF2, and 0.01 to 10 moles of Li2CO3; wherein the molar ratio of TeO2 to GeO2 is (4 to 7):

1.

2. The microcrystalline glass according to claim 1, characterized in that, include: 50 to 70 moles of the TeO2, 10 to 30 moles of the ZnO, 0.01 to 3 moles of the ErF3, 5 to 10 moles of the PbF2, and 1 to 5 moles of the Li2CO3.

3. A method for preparing upconversion luminescent glass crystals according to any one of claims 1 to 2, characterized in that, include: (1) TeO2, ZnO, GeO2, ErF3, PbF2 and Li2CO3 were mixed and dried according to the formula to obtain mixed raw materials; (2) The mixed raw materials are melted in air to obtain a mixed glass melt; (3) The mixed glass liquid is subjected to molding treatment to obtain upconversion luminescent microcrystalline glass.

4. The method according to claim 3, characterized in that, In step (1), at least one of the following conditions must be met: The mixing process includes grinding and mixing; The mixing process was carried out in an agate mortar; The drying temperature is 100℃~400℃ and the time is 1h~5h.

5. The method according to claim 3, characterized in that, In step (2), the melting process is carried out at a temperature of 800℃~1100℃ for a time of 10min~80min; and / or the melting process is carried out in a platinum crucible.

6. The method according to claim 3, characterized in that, In step (3), the forming process includes: pouring the molten glass into a mold, annealing it at 240℃~310℃ for 2h~6h, and then performing microcrystallization treatment at 330℃~410℃.

7. An apparatus comprising an upconversion luminescent glass crystal according to any one of claims 1 to 2, or an upconversion luminescent glass crystal prepared by any one of claims 3 to 6.

8. The apparatus according to claim 7, characterized in that, The laser wavelength used to excite the upconversion luminescent microcrystalline glass to emit light is 1550 nm.

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