A blue light-excited garnet-structured near-infrared luminescent material, its preparation method and application

Abstract

This invention discloses a blue light-excited garnet-structured near-infrared luminescent material, its preparation method, and its applications. The molecular formula of the near-infrared luminescent material is Re. 3‑x B x A2B 3‑y C y O 12 :zCr 3+ , of which 0

Description

Technical Field

[0001] This application belongs to the field of inorganic luminescent materials technology, and more specifically, relates to a blue light-excited garnet-structured near-infrared luminescent material, its preparation method, and its application. Background Technology

[0002] Near-infrared spectroscopy, particularly the near-infrared I region within the "biological tissue optical window" ranging from 650 nm to 900 nm, shows immense promise in biomedical imaging, non-destructive testing, security monitoring, and food quality analysis due to its low absorption, low scattering, and high penetration depth in biological tissues. Light sources in this band are the core components for realizing these applications. Longer emission wavelengths offer unique advantages: deeper tissue penetration and a higher signal-to-noise ratio. Furthermore, the vicinity of 900 nm can excite second-order harmonics and combination frequencies of stretching vibrations such as C–H, N–H, and O–H, doubling the variety of chemical bonds that can be identified compared to the shorter wavelength region, providing a richer spectral fingerprint for quantitative analysis of deep components and identification of concealed substances.

[0003] Currently, the main methods for obtaining near-infrared light sources include traditional halogen tungsten filament lamps, LEDs, and laser diodes. However, halogen lamps have low lamp efficacy, large size, and generate significant heat; while high-performance near-infrared LEDs and laser diodes are expensive and have limitations in applications requiring large-area, uniform illumination. Therefore, developing a fluorescent conversion material that can be effectively excited by low-cost, high-efficiency, and miniaturized commercial blue LEDs to emit high-intensity near-infrared light has become a research hotspot in academia and industry.

[0004] Among numerous near-infrared luminescent materials, garnet-structured materials are considered ideal matrix materials due to their stable crystal structure, excellent physicochemical properties, and tunable luminescence characteristics. Existing Cr... 3+ Although doped garnet materials (such as gallium garnet) have emission wavelengths in the range of 650-1300 nm, their main emission peak is usually located in the range of 650-800 nm. This band is at the short-wavelength edge of the biological optical window, and its tissue penetration ability is relatively limited. It is also easy to interfere with the autofluorescence background of organisms, resulting in a decrease in signal-to-noise ratio.

[0005] Therefore, it is particularly important to develop a near-infrared luminescent material with a garnet configuration that can be efficiently excited by commercial blue LEDs and has a longer wavelength of emission peak. This is not only an important supplement to the existing near-infrared fluorescent material system, but also a key to promoting the development of next-generation high-sensitivity bioimaging, high signal-to-noise ratio nondestructive testing, and high-performance night vision technologies, and has significant scientific research value and broad market application value. Summary of the Invention

[0006] The primary objective of the present invention is to overcome the defects or deficiencies of existing garnet-structured near-infrared luminescent materials excited by blue light, and to provide a near-infrared luminescent material. The emission peak of this near-infrared luminescent material is at 900 - 910 nm, and the full width at half maximum is 180 - 190 nm.

[0007] Another objective of the present invention is to provide a preparation method for the above-mentioned near-infrared luminescent material.

[0008] Another objective of the present invention is to provide the application of the above-mentioned near-infrared luminescent material in the preparation of near-infrared LED light sources.

[0009] In order to achieve the above objectives, the present invention is realized through the following technical solutions: A garnet-structured near-infrared luminescent material excited by blue light, the molecular formula of the near-infrared luminescent material is Re 3-x B x A2B 3-y C y O 12 :zCr 3+ , where 0 < x < 0.2, 0 < y < 0.2, 0.01 < z ≤ 0.1; the Re is at least one of Lu, Gd or Yb; the A is at least one of Te, W or Mo; the B is at least one of Li or Na; the C is at least one of Al or Ga.

[0010] The present invention selects at least one of Lu, Gd or Yb as the rare earth element, at least one of Te, W or Mo as the hexavalent metal element, at least one of Li or Na as the alkali metal element, and at least one of Al or Ga as the trivalent metal element, and constructs a new garnet-structured matrix material according to a specific stoichiometric ratio. By doping trivalent chromium ions, a new garnet-structured near-infrared luminescent material is prepared. Compared with the existing garnet-structured matrix materials, the new garnet-structured matrix material prepared by the present invention can achieve a more uniform energy distribution, concentrate the energy on a single luminescence center, significantly improve the energy transfer efficiency, and further improve the penetration ability of near-infrared light, so that the prepared near-infrared luminescent material emits long-wavelength (emission peak greater than 900 nm), broadband near-infrared light under blue light excitation.

[0011] Preferably, the emission peak of the near-infrared luminescent material is at 900 - 910 nm, and the full width at half maximum is 180 - 190 nm.

[0012] The preparation method of the above-mentioned near-infrared luminescent material is also within the protection scope of the present invention, and includes the following steps: S1. Weigh out the Re-containing compound, the A-containing compound, the B-containing compound, the C-containing compound, and the chromium-containing compound according to the stoichiometric ratio, mix and grind them until homogeneous, and then pre-calcine them to obtain the mixture; S2. Cool the mixture, grind it evenly, and then calcine it to obtain the near-infrared luminescent material.

[0013] Preferably, the Re-containing compound is at least one of a Re-containing carbonate, a Re-containing nitrate, or a Re-containing oxide.

[0014] Preferably, the A-containing compound is at least one of an A-containing nitrate or an A-containing oxide.

[0015] Preferably, the B-containing compound is at least one of a B-containing carbonate, a B-containing oxide, or a B-containing hydroxide.

[0016] Preferably, the C-containing compound is at least one of a C-containing carbonate or a C-containing oxide.

[0017] Preferably, the chromium-containing compound is at least one of a chromium-containing nitrate or a chromium-containing oxide.

[0018] Preferably, the pre-firing temperature is 650~750℃.

[0019] Preferably, the preheating rate is 1~3℃ / min.

[0020] The heating rate is a key parameter controlling crystal nucleation and growth kinetics. Excessive heating can lead to premature decomposition of local components, hindering the development of a complete crystal structure and ultimately affecting the phase purity and crystal quality of the material. More preferably, the heating rate for pre-firing is 1~2℃ / min. Most preferably, the heating rate for pre-firing is 1℃ / min.

[0021] Preferably, the pre-firing time is 5-7 hours.

[0022] Preferably, the pre-firing is carried out in a tube furnace or a muffle furnace.

[0023] Preferably, the heating atmosphere for preheating is air.

[0024] Preferably, the cooling is natural cooling to room temperature.

[0025] Preferably, the calcination temperature is 800~900℃.

[0026] Preferably, the heating rate of the calcination is 1~3℃ / min.

[0027] More preferably, the calcination heating rate is first increased to 650-750°C at a rate of 1-2°C / min, and then increased to 800-900°C at a rate of 2-3°C / min. This segmented heating method effectively controls energy consumption while ensuring the quality of material crystallization, making it more suitable for large-scale production.

[0028] Preferably, the calcination time is 9-11 hours.

[0029] Preferably, the calcination is carried out in a tube furnace or a muffle furnace.

[0030] Preferably, the heating atmosphere for calcination is air.

[0031] Preferably, the calcination process further includes steps of natural cooling to room temperature and grinding evenly.

[0032] The application of the aforementioned near-infrared luminescent materials in the preparation of near-infrared LED light sources is also within the scope of protection of this invention.

[0033] Compared with the prior art, the beneficial effects of the present invention include: The near-infrared luminescent material provided by this invention can be effectively excited by blue light (400~470nm) to emit broadband near-infrared light, with its main emission peak located at 900~910nm and a half-maximum width at half-maximum of 180~190nm. Furthermore, the preparation process of the near-infrared luminescent material provided by this invention is simple, the synthesis conditions are easily achievable and controllable, making it suitable for large-scale production and allowing for wide application in near-infrared LED light sources. Attached Figure Description

[0034] Figure 1 This is the X-ray diffraction pattern of the luminescent material prepared in Example 1.

[0035] Figure 2 This is the excitation and emission spectrum of the luminescent material prepared in Example 1.

[0036] Figure 3 This is the excitation and emission spectrum of the luminescent material prepared in Example 2.

[0037] Figure 4 This is the excitation and emission spectrum of the luminescent material prepared in Example 3.

[0038] Figure 5 This is the emission spectrum of the luminescent material prepared in Example 4.

[0039] Figure 6 This is the emission spectrum of the luminescent material prepared in Example 5.

[0040] Figure 7 This is the emission spectrum of the luminescent material prepared in Example 6.

[0041] Figure 8 This is the emission spectrum of the luminescent material prepared in Example 7.

[0042] Figure 9 This is the emission spectrum of the luminescent material prepared in Example 8.

[0043] Figure 10 This is the emission spectrum of the luminescent material prepared in Example 9.

[0044] Figure 11 This is the emission spectrum of the luminescent material prepared in Example 10.

[0045] Figure 12 This is the emission spectrum of the luminescent material prepared in Example 11.

[0046] Figure 13 This is the emission spectrum of the luminescent material prepared in Example 12.

[0047] Figure 14 This is the emission spectrum of the luminescent material prepared in Comparative Example 1.

[0048] Figure 15 This is the X-ray diffraction pattern of the luminescent material prepared in Comparative Example 2.

[0049] Figure 16 This is the X-ray diffraction pattern of the luminescent material prepared in Comparative Example 3.

[0050] Figure 17 The emission spectra of the luminescent material prepared in Example 1 at different alcohol concentrations are shown.

[0051] Figure 18 The emission spectra of the luminescent material prepared in Comparative Example 1 at different alcohol concentrations are shown. Detailed Implementation

[0052] The present invention will be further described below with reference to embodiments and comparative examples. These embodiments are merely typical descriptions of the present invention, but the present invention is not limited thereto. Unless otherwise specified, the test methods used in the following embodiments and comparative examples are conventional methods, and the raw materials and reagents used are commercially available from conventional commercial sources.

[0053] Example 1 This embodiment provides a blue light-excited garnet-structured near-infrared luminescent material with the molecular formula Lu. 2.9 Li 0.1 Te2Li 2.9 Ga 0.1 O 12 0.02Cr 3+The preparation method of the near-infrared luminescent material includes the following steps: S1. Weigh out lutetium oxide (0.0906 mol), tellurium dioxide (0.125 mol), lithium carbonate (0.0938 mol), gallium oxide (0.0031 mol), and chromium trioxide (0.0006 mol) according to the stoichiometric ratio. Mix and grind them thoroughly until homogeneous, then place them in an alumina crucible and put them in a high-temperature tube furnace. Pre-calcine them at 700°C for 6 hours under air conditions with a heating rate of 1°C / min to obtain the mixture. S2. After the mixture is naturally cooled to room temperature, it is ground uniformly again and placed in a high-temperature tube furnace. Under air conditions, the temperature is increased to 700°C at a heating rate of 1°C / min, and then increased to 850°C at a heating rate of 2.5°C / min for calcination for 10 hours. After naturally cooling to room temperature, it is taken out and ground uniformly again to obtain the near-infrared luminescent material.

[0054] The near-infrared luminescent material prepared in this embodiment was characterized by X-ray diffraction pattern, and the results are as follows: Figure 1 As shown in the figure. The results indicate that the near-infrared luminescent material prepared in this embodiment is a pure phase.

[0055] The excitation and emission spectra of the near-infrared luminescent material prepared in this embodiment were measured at a wavelength of 456 nm. The results are as follows: Figure 2 As shown. Figure 2 The corresponding data is shown in Table 1.

[0056] Example 2 This embodiment provides a blue light-excited garnet-structured near-infrared luminescent material with the molecular formula Lu. 2.9 Na 0.1 Te2Na 2.9 Ga 0.1 O 12 0.04Cr 3+ The preparation method of the near-infrared luminescent material includes the following steps: S1. Weigh out lutetium oxide (0.0906 mol), tellurium dioxide (0.125 mol), sodium carbonate (0.0938 mol), gallium oxide (0.0031 mol), and chromium trioxide (0.0012 mol) according to the stoichiometric ratio. Mix and grind them thoroughly until homogeneous, then place them in an alumina crucible and put them in a high-temperature tube furnace. Pre-calcine them at 700°C for 6 hours under air conditions with a heating rate of 1°C / min to obtain the mixture. S2. After the mixture is naturally cooled to room temperature, it is ground uniformly again and placed in a high-temperature tube furnace. Under air conditions, the temperature is increased to 700°C at a heating rate of 1°C / min, and then increased to 850°C at a heating rate of 2.5°C / min for calcination for 10 hours. After naturally cooling to room temperature, it is taken out and ground uniformly again to obtain the near-infrared luminescent material.

[0057] The excitation and emission spectra of the near-infrared luminescent material prepared in this embodiment were measured at a wavelength of 456 nm. The results are as follows: Figure 3 As shown. Figure 3 The corresponding data is shown in Table 1.

[0058] Example 3 This embodiment provides a blue light-excited garnet-structured near-infrared luminescent material with the molecular formula Lu. 2.9 Li 0.1 Te2Li 2.9 Al 0.1 O 12 0.06Cr 3+ The preparation method of the near-infrared luminescent material includes the following steps: S1. Weigh out lutetium oxide (0.0906 mol), tellurium dioxide (0.125 mol), lithium carbonate (0.0938 mol), aluminum oxide (0.0031 mol), and chromium trioxide (0.0018 mol) according to the stoichiometric ratio. Mix and grind them thoroughly until homogeneous, then place them in a corundum crucible and put them in a high-temperature tube furnace. Pre-calcine them at 700°C for 6 hours under air conditions with a heating rate of 1°C / min to obtain the mixture. S2. After the mixture is naturally cooled to room temperature, it is ground uniformly again and placed in a high-temperature tube furnace. Under air conditions, the temperature is increased to 700°C at a heating rate of 1°C / min, and then increased to 850°C at a heating rate of 2.5°C / min for calcination for 10 hours. After naturally cooling to room temperature, it is taken out and ground uniformly again to obtain the near-infrared luminescent material.

[0059] The excitation and emission spectra of the near-infrared luminescent material prepared in this embodiment were measured at a wavelength of 456 nm. The results are as follows: Figure 4 As shown. Figure 4 The corresponding data is shown in Table 1.

[0060] Example 4 This embodiment provides a blue light-excited garnet-structured near-infrared luminescent material with the molecular formula Lu. 2.9 Na 0.1 Te2Na 2.9 Al 0.1 O 12 0.08Cr3+ The preparation method of the near-infrared luminescent material includes the following steps: S1. Weigh out lutetium oxide (0.0906 mol), tellurium dioxide (0.125 mol), sodium carbonate (0.0938 mol), aluminum oxide (0.0031 mol), and chromium trioxide (0.0024 mol) according to the stoichiometric ratio. Mix and grind them thoroughly until homogeneous, then place them in an alumina crucible and put them in a high-temperature tube furnace. Pre-calcine them at 700°C for 6 hours under air conditions with a heating rate of 1°C / min to obtain the mixture. S2. After the mixture is naturally cooled to room temperature, it is ground uniformly again and placed in a high-temperature tube furnace. Under air conditions, the temperature is increased to 700°C at a heating rate of 1°C / min, and then increased to 850°C at a heating rate of 2.5°C / min for calcination for 10 hours. After naturally cooling to room temperature, it is taken out and ground uniformly again to obtain the near-infrared luminescent material.

[0061] The near-infrared luminescent material prepared in this embodiment was subjected to emission spectroscopy testing at a wavelength of 456 nm, and the results are as follows: Figure 5 As shown. Figure 5 The corresponding data is shown in Table 1.

[0062] Example 5 This embodiment provides a blue light-excited garnet-structured near-infrared luminescent material with the molecular formula Lu. 2.9 Na 0.1 Te2Na 2.9 Al 0.1 O 12 0.1Cr 3+ The preparation method of the near-infrared luminescent material includes the following steps: S1. Weigh out lutetium oxide (0.0906 mol), tellurium dioxide (0.125 mol), sodium carbonate (0.0938 mol), aluminum oxide (0.0031 mol), and chromium trioxide (0.003 mol) according to the stoichiometric ratio. Mix and grind them thoroughly until homogeneous, then place them in a corundum crucible and put them in a high-temperature tube furnace. Pre-calcine them at 700°C for 6 hours under air conditions with a heating rate of 1°C / min to obtain the mixture. S2. After the mixture is naturally cooled to room temperature, it is ground uniformly again and placed in a high-temperature tube furnace. Under air conditions, the temperature is increased to 700°C at a heating rate of 1°C / min, and then increased to 850°C at a heating rate of 2.5°C / min for calcination for 10 hours. After naturally cooling to room temperature, it is taken out and ground uniformly again to obtain the near-infrared luminescent material.

[0063] The near-infrared luminescent material prepared in this embodiment was subjected to emission spectroscopy testing at a wavelength of 456 nm, and the results are as follows: Figure 6 As shown. Figure 6 The corresponding data is shown in Table 1.

[0064] Example 6 This embodiment provides a blue light-excited garnet-structured near-infrared luminescent material with the molecular formula Gd. 2.9 Li 0.1 W2Li 2.9 Al 0.1 O 12 0.02Cr 3+ The preparation method of the near-infrared luminescent material includes the following steps: S1. Weigh out gadolinium oxide (0.0906 mol), tungsten trioxide (0.125 mol), lithium carbonate (0.0938 mol), aluminum oxide (0.0031 mol), and chromium trioxide (0.0006 mol) according to the stoichiometric ratio. Mix and grind them thoroughly until homogeneous, then place them in an alumina crucible and put them in a high-temperature tube furnace. Pre-calcine them at 700°C for 6 hours under air conditions with a heating rate of 1°C / min to obtain the mixture. S2. After the mixture is naturally cooled to room temperature, it is ground uniformly again and placed in a high-temperature tube furnace. Under air conditions, the temperature is increased to 700°C at a heating rate of 1°C / min, and then increased to 850°C at a heating rate of 2.5°C / min for calcination for 10 hours. After naturally cooling to room temperature, it is taken out and ground uniformly again to obtain the near-infrared luminescent material.

[0065] The near-infrared luminescent material prepared in this embodiment was subjected to emission spectroscopy testing at a wavelength of 456 nm, and the results are as follows: Figure 7 As shown. Figure 7 The corresponding data is shown in Table 1.

[0066] Example 7 This embodiment provides a blue light-excited garnet-structured near-infrared luminescent material with the molecular formula Gd. 2.9 Na 0.1 W2Na 2.9 Al 0.1 O 12 0.04Cr 3+ The preparation method of the near-infrared luminescent material includes the following steps: S1. Weigh out gadolinium oxide (0.0906 mol), tungsten trioxide (0.125 mol), sodium carbonate (0.0938 mol), aluminum oxide (0.0031 mol), and chromium trioxide (0.0012 mol) according to the stoichiometric ratio. Mix and grind them thoroughly until homogeneous, then place them in an alumina crucible and put them in a high-temperature tube furnace. Pre-calcine them at 700°C for 6 hours under air conditions with a heating rate of 1°C / min to obtain the mixture. S2. After the mixture is naturally cooled to room temperature, it is ground uniformly again and placed in a high-temperature tube furnace. Under air conditions, the temperature is increased to 700°C at a heating rate of 1°C / min, and then increased to 850°C at a heating rate of 2.5°C / min for calcination for 10 hours. After naturally cooling to room temperature, it is taken out and ground uniformly again to obtain the near-infrared luminescent material.

[0067] The near-infrared luminescent material prepared in this embodiment was subjected to emission spectroscopy testing at a wavelength of 456 nm, and the results are as follows: Figure 8 As shown. Figure 8 The corresponding data is shown in Table 1.

[0068] Example 8 This embodiment provides a blue light-excited garnet-structured near-infrared luminescent material with the molecular formula Gd. 2.9 Li 0.1 W2Li 2.9 Ga 0.1 O 12 0.06Cr 3+ The preparation method of the near-infrared luminescent material includes the following steps: S1. Weigh out gadolinium oxide (0.0906 mol), tungsten trioxide (0.125 mol), lithium carbonate (0.0938 mol), gallium oxide (0.0031 mol), and chromium trioxide (0.0018 mol) according to the stoichiometric ratio. Mix and grind them thoroughly until homogeneous, then place them in an alumina crucible and put them in a high-temperature tube furnace. Pre-calcine them at 700°C for 6 hours under air conditions with a heating rate of 1°C / min to obtain the mixture. S2. After the mixture is naturally cooled to room temperature, it is ground uniformly again and placed in a high-temperature tube furnace. Under air conditions, the temperature is increased to 700°C at a heating rate of 1°C / min, and then increased to 850°C at a heating rate of 2.5°C / min for calcination for 10 hours. After naturally cooling to room temperature, it is taken out and ground uniformly again to obtain the near-infrared luminescent material.

[0069] The near-infrared luminescent material prepared in this embodiment was subjected to emission spectroscopy testing at a wavelength of 456 nm, and the results are as follows: Figure 9 As shown. Figure 9 The corresponding data is shown in Table 1.

[0070] Example 9 This embodiment provides a blue light-excited garnet-structured near-infrared luminescent material with the molecular formula Gd. 2.9 Na 0.1 W2Na 2.9 Ga 0.1 O 12 0.02Cr3+ The preparation method of the near-infrared luminescent material includes the following steps: S1. Weigh out gadolinium oxide (0.0906 mol), tungsten trioxide (0.125 mol), sodium carbonate (0.0938 mol), gallium oxide (0.0031 mol), and chromium trioxide (0.0006 mol) according to the stoichiometric ratio. Mix and grind them thoroughly until homogeneous, then place them in an alumina crucible and put them in a high-temperature tube furnace. Pre-calcine them at 700°C for 6 hours under air conditions with a heating rate of 1°C / min to obtain the mixture. S2. After the mixture is naturally cooled to room temperature, it is ground uniformly again and placed in a high-temperature tube furnace. Under air conditions, the temperature is increased to 700°C at a heating rate of 1°C / min, and then increased to 850°C at a heating rate of 2.5°C / min for calcination for 10 hours. After naturally cooling to room temperature, it is taken out and ground uniformly again to obtain the near-infrared luminescent material.

[0071] The near-infrared luminescent material prepared in this embodiment was subjected to emission spectroscopy testing at a wavelength of 456 nm, and the results are as follows: Figure 10 As shown. Figure 10 The corresponding data is shown in Table 1.

[0072] Example 10 This embodiment provides a blue light-excited garnet-structured near-infrared luminescent material with the molecular formula Yb. 2.9 Na 0.1 Mo2Na 2.9 Ga 0.1 O 12 0.02Cr 3+ The preparation method of the near-infrared luminescent material includes the following steps: S1. Weigh out ytterbium oxide (0.0906 mol), molybdenum trioxide (0.125 mol), sodium carbonate (0.0938 mol), gallium oxide (0.0031 mol), and chromium trioxide (0.0006 mol) according to the stoichiometric ratio. Mix and grind them thoroughly until homogeneous, then place them in an alumina crucible and put them into a high-temperature tube furnace. Pre-calcine them at 700°C for 6 hours under air conditions with a heating rate of 1°C / min to obtain the mixture. S2. After the mixture is naturally cooled to room temperature, it is ground uniformly again and placed in a high-temperature tube furnace. Under air conditions, the temperature is increased to 700°C at a heating rate of 1°C / min, and then increased to 850°C at a heating rate of 2.5°C / min for calcination for 10 hours. After naturally cooling to room temperature, it is taken out and ground uniformly again to obtain the near-infrared luminescent material.

[0073] The near-infrared luminescent material prepared in this embodiment was subjected to emission spectroscopy testing at a wavelength of 456 nm, and the results are as follows: Figure 11 As shown. Figure 11 The corresponding data is shown in Table 1.

[0074] Example 11 This embodiment provides a blue light-excited garnet-structured near-infrared luminescent material with the molecular formula Yb. 2.9 Li 0.1 Mo2Li 2.9 Ga 0.1 O 12 0.06Cr 3+ The preparation method of the near-infrared luminescent material includes the following steps: S1. Weigh out ytterbium oxide (0.0906 mol), molybdenum trioxide (0.125 mol), lithium carbonate (0.0938 mol), gallium oxide (0.0031 mol), and chromium trioxide (0.0018 mol) according to the stoichiometric ratio. Mix and grind them thoroughly until homogeneous, then place them in a corundum crucible and put them into a high-temperature tube furnace. Preheat the furnace to 700°C for 6 hours under air conditions at a heating rate of 1°C / min. After naturally cooling to room temperature, remove the furnace and grind it again until homogeneous to obtain the mixture. S2. After the mixture is naturally cooled to room temperature, it is ground uniformly again and placed in a high-temperature tube furnace. Under air conditions, the temperature is increased to 700°C at a heating rate of 1°C / min, and then increased to 850°C at a heating rate of 2.5°C / min for calcination for 10 hours. After naturally cooling to room temperature, it is taken out and ground uniformly again to obtain the near-infrared luminescent material.

[0075] The near-infrared luminescent material prepared in this embodiment was subjected to emission spectroscopy testing at a wavelength of 456 nm, and the results are as follows: Figure 12 As shown. Figure 12 The corresponding data is shown in Table 1.

[0076] Example 12 This embodiment provides a blue light-excited garnet-structured near-infrared luminescent material with the molecular formula Yb. 2.9 Li 0.1 Mo2Li 2.9 Al 0.1 O 12 0.02Cr 3+ The preparation method of the near-infrared luminescent material includes the following steps: S1. Weigh out ytterbium oxide (0.0906 mol), molybdenum trioxide (0.125 mol), lithium carbonate (0.0938 mol), aluminum oxide (0.0031 mol), and chromium trioxide (0.0006 mol) according to the stoichiometric ratio. Mix and grind them thoroughly until homogeneous, then place them in a corundum crucible and put them in a high-temperature tube furnace. Pre-calcine them at 700°C for 6 hours under air conditions with a heating rate of 1°C / min to obtain the mixture. S2. After the mixture is naturally cooled to room temperature, it is ground uniformly again and placed in a high-temperature tube furnace. Under air conditions, the temperature is increased to 700°C at a heating rate of 1°C / min, and then increased to 850°C at a heating rate of 2.5°C / min for calcination for 10 hours. After naturally cooling to room temperature, it is taken out and ground uniformly again to obtain the near-infrared luminescent material.

[0077] The near-infrared luminescent material prepared in this embodiment was subjected to emission spectroscopy testing at a wavelength of 456 nm, and the results are as follows: Figure 13 As shown. Figure 13 The corresponding data is shown in Table 1.

[0078] Comparative Example 1 This comparative example provides a blue light-excited garnet-structured near-infrared luminescent material with the molecular formula Y3Al5O. 12 0.02Cr 3+ The preparation method of the near-infrared luminescent material includes the following steps: S1. Weigh out yttrium oxide (0.0938 mol), aluminum oxide (0.1563 mol), and chromium trioxide (0.0006 mol) according to the stoichiometric ratio. Mix and grind them thoroughly until uniform, then place them in a corundum crucible and put them in a high-temperature tube furnace. Calcinate them at 1550°C for 5 hours under air conditions with a heating rate of 5°C / min. After naturally cooling to room temperature, remove them and grind them uniformly again to obtain the near-infrared luminescent material.

[0079] The near-infrared luminescent material prepared in this embodiment was subjected to emission spectroscopy testing at a wavelength of 456 nm, and the results are as follows: Figure 14 As shown. Figure 14 The corresponding data is shown in Table 1.

[0080] Comparative Example 2 This comparative example provides a blue light-excited garnet-structured near-infrared luminescent material, which differs from Example 1 only in step S2, specifically: S2. After the mixture is naturally cooled to room temperature, it is ground uniformly again and placed in a high-temperature tube furnace. Under air conditions, the temperature is increased to 700°C at a heating rate of 1°C / min, and then increased to 1350°C at a heating rate of 2.5°C / min for calcination for 10 hours. After naturally cooling to room temperature, it is taken out and ground uniformly again to obtain the near-infrared luminescent material.

[0081] The near-infrared luminescent material prepared in this embodiment was characterized by X-ray diffraction pattern, and the results are as follows: Figure 15 As shown. The results indicate that the near-infrared luminescent material prepared in this embodiment is not a pure phase.

[0082] Comparative Example 3 This comparative example provides a blue light-excited garnet-structured near-infrared luminescent material, which differs from Example 1 only in step S2, specifically: S2. After the mixture is naturally cooled to room temperature, it is ground uniformly again and placed in a high-temperature tube furnace. Under air conditions, the temperature is increased to 850°C at a heating rate of 5°C / min and calcined for 10 hours. After naturally cooling to room temperature, it is taken out and ground uniformly again to obtain the near-infrared luminescent material.

[0083] The near-infrared luminescent material prepared in this embodiment was characterized by X-ray diffraction pattern, and the results are as follows: Figure 16 As shown. The results indicate that the near-infrared luminescent material prepared in this embodiment is not a pure phase.

[0084] Performance testing The near-infrared luminescent materials prepared in the above embodiments and comparative examples were subjected to excitation spectroscopy tests at a wavelength of 456 nm. The specific test results are shown in Table 1.

[0085] Table 1 Performance results of the near-infrared luminescent materials prepared in each embodiment and comparative example

[0086] As shown in Table 1, the near-infrared luminescent materials provided by the present invention can all be effectively excited by blue light and emit broadband near-infrared light, with their main emission peaks all above 900 nm and their half-width at half-maximum emission peaks above 180 nm.

[0087] Application testing The near-infrared luminescent materials prepared in Example 1 and Comparative Example 1 were tested for application in detecting alcohol solution concentration. The test results are as follows: Figure 17 and Figure 18 As shown. The specific test method is as follows: two near-infrared luminescent materials are irradiated with 456nm excitation light, and the near-infrared light emitted by them is irradiated onto a cuvette containing an alcohol solution, and their transmission spectra are collected using a spectrometer.

[0088] from Figure 17 It can be seen that the near-infrared luminescent material prepared in Example 1 shows a spectral intensity change at 965 nm due to the change in OH bond concentration, while the near-infrared luminescent material prepared in Comparative Example 1 shows almost no spectral intensity change at 965 nm. This indicates that the near-infrared luminescent material prepared in this invention has advantages over near-infrared luminescent materials with emission peaks below 900 nm in terms of solution composition or concentration detection.

[0089] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A near-infrared luminescent material with a garnet configuration excited by blue light, characterized in that, The molecular formula of the near-infrared luminescent material is Re 3-x B x A2B 3-y C y O 12 :zCr 3+ , where 0 < x < 0.2, 0 < y < 0.2, 0.01 < z ≤ 0.1; the Re is at least one of Lu, Gd or Yb; the A is at least one of Te, W or Mo; the B is at least one of Li or Na; the C is at least one of Al or Ga; the emission peak of the near-infrared luminescent material is located at 900 - 910 nm, and the full width at half maximum is 180 - 190 nm.

2. The method for preparing the near-infrared luminescent material according to claim 1, characterized in that, Includes the following steps: S1. Weigh out the Re-containing compound, the A-containing compound, the B-containing compound, the C-containing compound, and the chromium-containing compound according to the stoichiometric ratio, mix and grind them until homogeneous, and then pre-calcine them to obtain the mixture; S2. Cool the mixture, grind it evenly, and then calcine it to obtain the near-infrared luminescent material.

3. The preparation method according to claim 2, characterized in that, The Re-containing compound is at least one of a Re-containing carbonate, a Re-containing nitrate, or a Re-containing oxide; And / or, the A-containing compound is at least one of an A-containing nitrate or an A-containing oxide; And / or, the B-containing compound is at least one of a B-containing carbonate, a B-containing oxide, or a B-containing hydroxide; And / or, the C-containing compound is at least one of a C-containing carbonate or a C-containing oxide; And / or, the chromium-containing compound is at least one of a chromium-containing nitrate or a chromium-containing oxide.

4. The preparation method according to claim 2, characterized in that, The pre-firing temperature is 650~750℃, and the pre-firing heating rate is 1~3℃ / min.

5. The preparation method according to claim 2, characterized in that, The calcination temperature is 800~900℃, and the calcination heating rate is 1~3℃ / min.

6. The preparation method according to claim 2, characterized in that, The preheating time is 5-7 hours.

7. The preparation method according to claim 2, characterized in that, The calcination time is 9-11 hours.

8. The preparation method according to claim 2, characterized in that, The heating atmosphere for the pre-firing or calcination is air.

9. The application of the near-infrared luminescent material of claim 1 in the preparation of near-infrared LED light sources.

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