Rare earth doped strontium lutetium antimonate up-conversion luminescent material and preparation method thereof

Abstract

The invention relates to the field of fluorescent materials in biomedicine and the like, and particularly discloses a rare earth doped strontium lutetium antimonate up-conversion luminescent material and a preparation method thereof, the material is Sr2Lu1-x-ySbO6: xEr < 3 + > and yYb < 3 + >, x is greater than or equal to 0.01 and less than or equal to 0.04, and y is greater than or equal to 0.05 and less than or equal to 0.35; the preparation method comprises the following steps: weighing strontium carbonate, lutetium oxide, erbium oxide, ytterbium oxide and antimony pentoxide according to a certain ratio as raw materials, adding a proper amount of absolute ethyl alcohol, fully stirring, drying, pressing into sheets, and sintering in a muffle furnace at 1350 DEG C for a period of time. The rare earth doped lutetium strontium antimonate up-conversion luminescent material has the beneficial effects that stronger green light is emitted, when erbium ions and ytterbium ions are at the optimal concentration, the novel luminescent material Sr2Lu0. 73SbO6: 0.02 Er < 3 + > and 0.25 Yb < 3 + > excites stronger green light at 526 nm, has a key effect in optical temperature sensing, and has a huge development prospect as a rare earth doped lutetium strontium antimonate up-conversion luminescent material.

Description

A rare earth-doped lutetium-strontium antimonate upconversion luminescent material and its preparation method Technical Field

[0001] This invention relates to the field of luminescent materials technology, and in particular to a rare-earth-doped lutetium-strontium antimonate upconversion luminescent material and its preparation method. Background Technology

[0002] Against the backdrop of continuous iteration and upgrading of laser and nanotechnology, rare earth-doped upconversion materials have become a research hotspot due to their advantages such as excellent optical stability, low biotoxicity, and resistance to photobleaching, showing great potential in fields such as 3D display and biomedicine. Meanwhile, the research on alkaline earth metals and rare earth oxides has developed for more than half a century. For example, the development and application of crystalline phases in the barium oxide-scandium oxide system has laid the foundation for the research and development of new composite oxide materials.

[0003] Upconversion luminescence has the characteristics of near-infrared excitation, large Stokes shift, long fluorescence lifetime, and good photostability. It has great application potential and good development prospects in fields such as biomedical imaging and detection, anti-counterfeiting and security, solar cells, photocatalysis, and temperature sensing. Rare earth-doped upconversion materials have extremely rich luminescence spectra, but there are some high-energy upconversion photons, which will more or less have some impact on biological cells.

[0004] Against this backdrop, rare-earth-doped lutetium-strontium antimonate-based upconversion luminescent materials have gradually come into the research spotlight. These materials, relying on the unique crystal structure and chemical stability of the lutetium-strontium antimonate matrix, can provide upconversion luminescence for Er... 3+ Yb 3+ Rare earth ions provide a suitable lattice environment, effectively suppressing concentration quenching effects and ensuring luminescence efficiency. By precisely controlling the rare earth ion doping ratio, high-efficiency luminescence at specific wavelengths can also be achieved. This not only continues the core advantages of rare earth upconversion materials but also demonstrates new possibilities in performance control, providing new material options for breakthroughs in related fields.

[0005] Common methods for preparing lutetium-strontium antimonate-based materials include high-temperature solid-state synthesis, co-precipitation, and sol-gel methods. Among these, the high-temperature solid-state synthesis method is the most widely used. This method involves mechanically stirring, drying, and pressing the powder into flakes, followed by high-temperature calcination to obtain the desired product. The high-temperature solid-state synthesis method is widely used in various fields because it offers advantages such as a short synthesis cycle, simple process, and high controllability.

[0006] In fields such as bio-imaging therapy, display lighting, and optoelectronic anti-counterfeiting, it is necessary to use lasers to irradiate the corresponding upconversion luminescent materials to obtain the corresponding colors. The stronger the degree of luminescence and the more identifiable the luminescence, the better the performance.

[0007] Therefore, based on the Sr2LuSbO6 upconversion matrix material, this solution develops and prepares an upconversion luminescent material that can obtain a strong green light of 526nm when irradiated by a 980nm laser, thereby contributing to the technological upgrading and application expansion in fields such as biomedicine. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a rare earth-doped lutetium strontium antimonate upconversion luminescent material and its preparation method, thereby solving the problem that existing upconversion luminescent materials cannot emit strong green light when irradiated by a 980nm laser.

[0009] The objective of this invention is achieved through the following technical solution: Firstly, a rare-earth-doped lutetium strontium antimonate upconversion luminescent material is provided, wherein the structural formula of the upconversion luminescent material is: Sr₂Lu 1-x-y SbO6:xEr 3+ ,yYb 3+ , where 0.01 ≤ x ≤ 0.04, 0.05 ≤ y ≤ 0.35.

[0010] Secondly, a method for preparing rare-earth-doped lutetium-strontium antimonate upconversion luminescent material is also disclosed. The steps are as follows: S1, strontium carbonate, lutetium oxide, erbium oxide, ytterbium oxide, and antimony pentoxide are weighed as raw materials. The molar ratio of elements Sr, Lu, Er, Yb, and Sb is required to be 2:(1-xy):x:y:1; where 0.01 ≤x≤ 0.04, 0.05 ≤y≤ 0.35; S2, the weighed raw materials are poured into a container, anhydrous ethanol is added, and the mixture is stirred evenly to obtain a suspension; S3, the suspension is allowed to stand until the supernatant and precipitate separate into layers, and then dried until the anhydrous ethanol is completely evaporated to obtain a mixture; S4, the mixture is made into discs; S5, the discs are placed in a high-temperature furnace, heated to 1350℃ and maintained for a period of time; then naturally cooled to room temperature, the sample is taken out, and then ground into powder to obtain the upconversion luminescent material.

[0011] Furthermore, in step S2, the amount of anhydrous ethanol added is such that there is 0.02g to 0.30g of raw material per milliliter of anhydrous ethanol in the suspension.

[0012] Furthermore, in step S3, the drying temperature is 30℃~65℃, and the drying time is 0.5h~3h.

[0013] Furthermore, in S4, the disc made from the mixture has a diameter of 1 cm and a thickness of 2 mm.

[0014] Furthermore, in S5, the temperature is raised to 1350°C and then maintained for 6 hours.

[0015] The present invention has the following advantages: (1) It can emit higher intensity green light, thereby improving the performance of the upconversion material; the emitted strong green light can promote the technological advancement in the corresponding field and has broad prospects; specifically, the present invention prepares a rare earth-doped lutetium strontium antimonate upconversion luminescent material Sr2Lu by doping rare earth ions into the Sr2LuSbO6 upconversion material and controlling the proportion accordingly. 0.73 SbO6: 0.02Er 3+ 0.25Yb 3+ ① Due to the similar radii and high matching degree of ytterbium, erbium, and lutetium ions, they readily enter the lattice of the main matrix Sr₂LuSbO₆ and modulate the crystal field, forming a suitable energy level environment in the material. This environment can improve the energy transfer efficiency from ytterbium to erbium ions, thereby enhancing the sensitization and green light emission energy of erbium ions (thus optimizing the upconversion luminescence performance of the material); ② Furthermore, by controlling the doping concentration of rare earth ions, their sensitization and emission capabilities in the matrix material can be improved, resulting in stronger green light emission, especially when both erbium and ytterbium ions are at their optimal concentrations. This is particularly true for the novel luminescent material (Sr₂LuSbO₆). 0.73 SbO6: 0.02Er 3+ 0.25Yb 3+ (1) Strong green light is excited at 526nm, which plays a key role in optical temperature sensing and has broad development prospects in fields such as biomedical imaging, optoelectronic devices and anti-counterfeiting labels; (2) The upconversion material synthesis method in this invention is simple, has a high yield, is energy-saving and environmentally friendly, and is suitable for industrial production. Attached Figure Description

[0016] Figure 1 shows the Sr2Lu under near-infrared 980 nm laser excitation. 0.75-x SbO6:xEr 3+ 0.25Yb 3+ Figure 2 shows the upconversion fluorescence spectra of Sr2Lu under near-infrared 980 nm laser excitation (x = 0.01, 0.02, 0.03, 0.04). 0.98-y SbO6: 0.02Er 3+ ,yYb 3+ Upconversion fluorescence spectra of the series (y = 0.05, 0.15, 0.25, 0.35); Figure 3 shows the Sr2Lu 0.75-x SbO6:xEr 3+ 0.25Yb 3+ Powder X-ray diffraction patterns of the series (x = 0.01, 0.02, 0.03, 0.04); Figure 4 shows the Sr2Lu 0.98-y SbO6: 0.02Er 3+ ,yYb 3+Powder X-ray diffraction patterns of the series (y = 0.05, 0.15, 0.25, 0.35); Figure 5 shows the Sr2Lu obtained in Example 1. 0.74 SbO6: 0.01Er 3+ 0.25Yb 3+ (x=0.01) Powder X-ray diffraction pattern; Figure 6 shows the Sr2Lu obtained in Example 1. 0.74 SbO6: 0.01Er 3+ 0.25Yb 3+ Upconversion fluorescence spectrum under near-infrared 980 nm laser excitation; Figure 7 shows the Sr2Lu obtained in Example 2. 0.73 SbO6: 0.02Er 3+ 0.25Yb 3+ (x=0.02) Powder X-ray diffraction pattern; Figure 8 shows the Sr2Lu obtained in Example 2. 0.73 SbO6: 0.02Er 3+ 0.25Yb 3+ Upconversion fluorescence spectrum under near-infrared 980 nm laser excitation; Figure 9 shows the Sr2Lu obtained in Example 3. 0.72 SbO6: 0.03Er 3+ 0.25Yb 3+ (x=0.03) Powder X-ray diffraction pattern; Figure 10 shows the Sr2Lu obtained in Example 3. 0.72 SbO6: 0.03Er 3+ 0.25Yb 3+ Upconversion fluorescence spectrum under near-infrared 980 nm laser excitation; Figure 11 shows the Sr2Lu obtained in Example 4. 0.83 SbO6: 0.02Er 3+ 0.15Yb 3+ (y = 0.15) Powder X-ray diffraction pattern; Figure 12 shows the Sr2Lu obtained in Example 4. 0.83 SbO6: 0.02Er 3+ 0.15Yb 3+ Upconversion fluorescence spectrum under near-infrared 980 nm laser excitation; Figure 13 shows the Sr2Lu obtained in Example 5. 0.63 SbO6: 0.02Er 3+ 0.35Yb 3+ (y = 0.35) Powder X-ray diffraction pattern; Figure 14 shows the Sr2Lu obtained in Example 5. 0.63 SbO6: 0.02Er 3+ 0.35Yb 3+The upconversion fluorescence spectrum under near-infrared 980 nm laser excitation; Figure 15 is the X-ray diffraction spectrum of Sr2LuSbO6 powder obtained in Example 6. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0019] This solution provides a rare-earth-doped lutetium strontium antimonate upconversion luminescent material with the structural formula: Sr₂Lu. 1-x-y SbO6:xEr 3+ ,yYb 3+ , where 0.01 ≤ x ≤ 0.04, 0.05 ≤ y ≤ 0.35.

[0020] The preparation method of this rare earth-doped lutetium strontium antimonate upconversion luminescent material includes the following steps: S1, strontium carbonate, lutetium oxide, erbium oxide, ytterbium oxide, and antimony pentoxide are weighed as raw materials. The molar ratio of Sr, Lu, Er, Yb, and Sb is required to be 2:(1-xy):x:y:1; where 0.01 ≤x ≤ 0.04, 0.05 ≤y ≤ 0.35; S2, Pour all the raw materials weighed in S1 into a beaker, add anhydrous ethanol, stir evenly to obtain a suspension; wherein, the amount of anhydrous ethanol added is such that there are 0.02g~0.30g of raw materials per milliliter of anhydrous ethanol in the suspension; S3, Let the suspension obtained in S2 stand until the supernatant and precipitate separate into layers, and then dry at 30℃~65℃ for 0.3h~3h to allow the anhydrous ethanol to evaporate completely to obtain a mixture; S4, Make the mixture into discs with a diameter of 1cm and a thickness of 2mm; S5, Place the prepared discs in a high-temperature furnace, heat to 1350℃ and maintain for 6h; then cool naturally to room temperature, take out the sample, and grind it into powder to obtain the upconversion luminescent material.

[0021] The following specific embodiments further illustrate this solution (it should be noted that in the following embodiments, the corresponding parameters do not specifically adopt the endpoint values ​​in the weights, which means that as long as the corresponding parameters are within the parameter range of the weights, they are acceptable).

[0022] (Comparative Example 1) In this embodiment, a rare-earth-doped lutetium strontium antimonate upconversion luminescent material was prepared. This material is Sr2Lu 0.74 SbO6:0.01Er 3+ 0.25Yb 3+ At this point, x = 0.01.

[0023] The preparation steps of the luminescent material in this embodiment are as follows: S1. Calculate the required amount of each raw material according to the molar ratio of Sr, Lu, Sb, Er, and Yb of 2:0.74:1:0.01:0.25, and weigh out 0.00371 mol of strontium carbonate, 0.00069 mol of lutetium oxide, 0.00093 mol of antimony pentoxide, 0.00001 mol of erbium oxide, and 0.00023 mol of ytterbium oxide; S2. Pour all the raw materials weighed in step 1 into a 25 mL beaker, add 20 mL of anhydrous ethanol, and stir thoroughly with a glass rod to mix the raw materials evenly, obtaining a suspension; S3. After the suspension obtained in step 2 has stood for 25 min, place it in a drying oven and dry it at 60 ℃ for 1 h. After the anhydrous ethanol in the beaker has completely evaporated, obtain the dried mixed raw material; S4. Press the mixed raw material obtained in step 3 into tablets with a thickness of 2 mm and a diameter of approximately 1 mm using a tablet press. The sample is in the form of a 1 cm disc and should be pressed at 20 MPa for 25 min to ensure close contact. S5. After pressing the disc in step 4, place it in a crucible and then in a muffle furnace. Heat the muffle furnace to 1350℃ and hold for 6 h. After completion, allow it to cool naturally to room temperature. Remove the sample and grind it thoroughly into a fine powder using an agate grinding cup to obtain the rare-earth-doped lutetium strontium antimonate upconversion luminescent material Sr2Lu. 0.74 SbO6: 0.01Er 3+ 0.25Yb 3+ .

[0024] The X-ray diffraction (XRD) spectrum of this embodiment is shown in Figure 5: It can be seen that the obtained Sr2Lu 0.74 SbO6:0.01Er 3+ 0.25Yb 3+ The phase conforms to the Sr2LuSbO6 crystal structure (PDF card number 76-0133), indicating that the Sr2Lu in this embodiment... 0.74 SbO6: 0.01Er 3+ 0.25Yb 3+ It is also a single-phase Sr2LuSbO6 with the target crystalline phase, indicating that the mole fraction of Er is 0.01. 3+ With Yb of 0.25 3+ Successfully incorporated into Sr2LuSbO6 crystals without altering the crystal structure.

[0025] The product in this embodiment (Sr2Lu) 0.74 SbO6: 0.01Er 3+ 0.25Yb 3+ The fluorescence spectrum of is shown in Figure 6.

[0026] (Comparative Example 2) In this example, rare earth-doped lutetium strontium antimonate upconversion luminescent material Sr2Lu was prepared according to the method described in Example 1 above. 0.73 SbO6: 0.02Er 3+ 0.25Yb 3+ At this point, x = 0.02. The only difference is the mass of lutetium oxide and erbium oxide weighed. Specifically, 0.00068 mol of lutetium oxide, 0.00002 mol of erbium oxide, 0.00371 mol of strontium carbonate, 0.00093 mol of antimony pentoxide, and 0.00023 mol of ytterbium oxide are weighed; all other steps remain unchanged. Finally, the rare-earth-doped lutetium-strontium antimony upconversion luminescent material Sr₂Lu is obtained. 0.73 SbO6: 0.02Er 3+ 0.25Yb 3+ The aim is to further increase the doping ratio of erbium ions, with the expectation of obtaining the optimal doping ratio of erbium ions to ytterbium ions.

[0027] The XRD pattern of this embodiment is shown in Figure 7: It can be seen that the obtained Sr2Lu 0.73 SbO6: 0.02Er 3+ 0.25Yb 3+ The phase conforms to the Sr2LuSbO6 crystal structure (PDF card number 76-0133), indicating that the product is a single-phase Sr2LuSbO6 that also has the target crystal phase.

[0028] The fluorescence spectrum of this embodiment is shown in Figure 8: It can be seen that under 980 nm near-infrared laser excitation, the obtained Sr2Lu 0.73 SbO6: 0.02Er 3+ 0.25Yb 3+ It has the highest green light emission intensity at a green light wavelength of 526 nm.

[0029] It should be noted that, compared with Example 1 (as shown by the comparison of Figures 8 and 6), the green light emission intensity of this embodiment is 3.6 times higher than that of Example 1.

[0030] (Comparative Example 3) In this example, rare earth-doped lutetium strontium antimonate upconversion luminescent material Sr2Lu was prepared according to the method described in Example 1 above. 0.72 SbO6: 0.03Er 3+0.25Yb 3+ At this point, x = 0.03. The only difference is the mass of lutetium oxide and erbium oxide weighed. Specifically, 0.00067 mol of lutetium oxide, 0.00003 mol of erbium oxide, 0.00371 mol of strontium carbonate, 0.00093 mol of antimony pentoxide, and 0.00023 mol of ytterbium oxide are weighed; all other steps remain unchanged. Finally, the rare-earth-doped lutetium-strontium antimony upconversion luminescent material Sr₂Lu is obtained. 0.72 SbO6: 0.03Er 3+ 0.25Yb 3+ The purpose is to verify, compared with Example 2, whether there is a maximum value for the erbium ion doping ratio.

[0031] The XRD pattern of this embodiment is shown in Figure 9: It can be seen that the obtained Sr2Lu 0.72 SbO6: 0.03Er 3+ 0.25Yb 3+ Its crystal structure conforms to the Sr2LuSbO6 crystal structure (PDF card number 76-0133).

[0032] The fluorescence spectrum of this embodiment is shown in Figure 10.

[0033] Comparing the XRD patterns of this embodiment with those of Embodiment 2, it can be seen that: under 980 nm infrared laser excitation, the obtained Sr2Lu 0.72 SbO6: 0.03Er 3+ 0.25Yb 3+ The green light emission intensity at 526 nm is compared to that of Sr2Lu obtained in Example 2. 0.73 SbO6: 0.02Er 3+ 0.25Yb 3+ The fluorescence quenching phenomenon was significantly reduced; this indicates (verifies) that the excessive erbium ion doping in this embodiment, although the phase remains unchanged, leads to fluorescence quenching due to the high concentration of doping.

[0034] (Comparative Example 4) In this example, rare earth-doped lutetium strontium antimonate upconversion luminescent material Sr2Lu was prepared according to the method of Example 2 above. 0.83 SbO6: 0.02Er 3+ 0.15Yb 3+At this point, y = 0.15. The only difference is the mass of lutetium oxide and ytterbium oxide weighed. Specifically, 0.00077 mol of lutetium oxide, 0.00014 mol of ytterbium oxide, 0.00371 mol of strontium carbonate, 0.00093 mol of antimony pentoxide, and 0.00002 mol of erbium oxide are weighed; other steps remain unchanged. Finally, the rare-earth-doped lutetium-strontium antimony upconversion luminescent material Sr₂Lu is obtained. 0.83 SbO6: 0.02Er 3+ 0.15Yb 3+ The purpose is to verify, compared with Example 2, whether there is a maximum value for the ytterbium ion doping ratio.

[0035] The XRD pattern of this embodiment is shown in Figure 11: It can be seen that the obtained Sr2Lu 0.83 SbO6: 0.02Er 3+ 0.15Yb 3+ Its crystal structure conforms to the Sr2LuSbO6 crystal structure (PDF card number 76-0133).

[0036] The fluorescence spectrum of this embodiment is shown in Figure 12.

[0037] Comparing the XRD patterns of this embodiment with those of Embodiment 2, it can be seen that: under 980nm infrared laser excitation, the obtained Sr2Lu 0.83 SbO6: 0.02Er 3+ 0.15Yb 3+ The green light emission intensity at 526 nm is compared to that of Sr2Lu obtained in Example 2. 0.73 SbO6: 0.02Er 3+ 0.25Yb 3+ The fluorescence intensity decreased significantly, which indicates (verifies) that the ytterbium ion doping in this embodiment was too low. Although the phase remained unchanged, the low concentration of doping resulted in a low fluorescence intensity.

[0038] (Comparative Example 5) In this example, rare earth-doped lutetium strontium antimonate upconversion luminescent material Sr2Lu was prepared according to the method of Example 2 above. 0.63 SbO6: 0.02Er 3+ 0.35Yb 3+At this point, y = 0.35. The only difference is the mass of lutetium oxide and ytterbium oxide weighed. Specifically, 0.00058 mol of lutetium oxide, 0.00032 mol of ytterbium oxide, 0.00371 mol of strontium carbonate, 0.00093 mol of antimony pentoxide, and 0.00002 mol of erbium oxide are weighed; all other steps remain unchanged. Finally, the rare-earth-doped lutetium-strontium antimony upconversion luminescent material Sr₂Lu is obtained. 0.63 SbO6: 0.02Er 3+ 0.35Yb 3+ The purpose is to verify, compared with Example 2, whether there is a maximum value for the ytterbium ion doping ratio.

[0039] The XRD pattern of this embodiment is shown in Figure 13: It can be seen that the obtained Sr2Lu 0.63 SbO6: 0.02Er 3+ 0.35Yb 3+ Its crystal structure conforms to the Sr2LuSbO6 crystal structure (PDF card number 76-0133).

[0040] The fluorescence pattern of this embodiment is shown in Figure 14.

[0041] Comparing the fluorescence images of this embodiment with those of Embodiment 2, it can be seen that under 980nm infrared laser excitation, the obtained Sr2Lu 0.63 SbO6: 0.02Er 3+ 0.35Yb 3+ The green light emission intensity at 526 nm is compared to that of Sr2Lu obtained in Example 2. 0.73 SbO6: 0.02Er 3+ 0.25Yb 3+ The fluorescence quenching phenomenon was significantly reduced; this demonstrates (verifies) that the excessive ytterbium ion doping in this embodiment, although the phase remains unchanged, leads to fluorescence quenching due to the high concentration of doping.

[0042] (Comparative Example 6) aims to verify the feasibility of the present invention under different time and temperature conditions through repeated experiments.

[0043] In this comparative example, the rare earth-doped lutetium-strontium antimonate upconversion luminescent matrix material Sr₂LuSbO₆ was prepared according to the method described in Example 2 above. Specifically, 0.00371 mol of strontium carbonate, 0.00093 mol of antimony pentoxide, and 0.00093 mol of lutetium oxide were weighed. However, the sintering step in Example 2, which involved heating the muffle furnace to 1350 °C and holding for 6 h, was changed to heating the muffle furnace to 1400 °C and holding for 8 h; all other steps remained unchanged. Finally, the rare earth-doped lutetium-strontium antimonate upconversion luminescent material Sr₂LuSbO₆ was obtained.

[0044] The XRD pattern of this comparative example is shown in Figure 15. It can be seen that the crystal structure of Sr₂LuSbO₆ obtained in this comparative example has more diffraction peaks compared to the standard Sr₂LuSbO₆ crystal structure (PDF card number 76-0133). The areas marked with asterisks represent the diffraction peaks of the second phase, indicating that the sample is not pure. This confirms that a pure phase can only be obtained by maintaining the sample at 1350℃ for 6 hours.

[0045] The above embodiments only illustrate preferred implementation methods, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this invention, and these all fall within the protection scope of this invention.

Claims

1. A rare-earth-doped lutetium-strontium antimonate upconversion luminescent material, characterized in that: The structural formula of the upconversion luminescent material is: Sr2Lu 1-x-y SbO6:xEr 3+ ,yYb 3+ , where 0.01 ≤ x ≤ 0.04, 0.05 ≤ y ≤ 0.

35.

2. A method for preparing a rare-earth-doped lutetium-strontium antimonate upconversion luminescent material, characterized in that... The steps are as follows: S1. Weigh strontium carbonate, lutetium oxide, erbium oxide, ytterbium oxide, and antimony pentoxide as raw materials. The molar ratio of elements Sr, Lu, Er, Yb, and Sb should be 2:(1-xy):x:y:1, where 0.01 ≤x≤0.04 and 0.05 ≤y≤0.

35. S2. Pour the weighed raw materials into a container, add anhydrous ethanol, and stir evenly to obtain a suspension. S3. Let the suspension stand until the supernatant and precipitate separate into layers, and then dry until the anhydrous ethanol is completely evaporated to obtain a mixture. S4. Make the mixture into discs. S5. Place the discs in a high-temperature furnace, heat to 1350℃ and maintain for a period of time. Then cool naturally to room temperature, remove the sample, and grind it into powder to obtain the upconversion luminescent material.

3. The preparation method of a rare earth-doped lutetium strontium antimonate upconversion luminescent material according to claim 2, characterized in that: In step S2, the amount of anhydrous ethanol added is such that there is 0.02g to 0.30g of raw material per milliliter of anhydrous ethanol in the suspension.

4. The method for preparing a rare-earth-doped lutetium-strontium antimonate upconversion luminescent material according to claim 3, characterized in that: In step S3, the drying temperature is 30℃~65℃ and the drying time is 0.5h~3h.

5. The preparation method of a rare-earth-doped lutetium-strontium antimonate upconversion luminescent material according to claim 3, characterized in that: In S4, the diameter of the disc supporting the mixture is 1 cm and the thickness is 2 mm.

6. A method for preparing a rare-earth-doped lutetium-strontium antimonate upconversion luminescent material according to claim 3 or 5, characterized in that: In S5, the temperature is raised to 1350℃ and then maintained for 6 hours.

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