A near-infrared luminescent material, a preparation method and application thereof

Abstract

The application relates to the technical field of light-emitting materials, in particular to a near-infrared light-emitting material and a preparation method and application thereof. 3+ The near-infrared light-emitting material can emit near-infrared red light with a wavelength range of 680-1100 nm under the excitation of 450 nm blue light, the excitation spectrum range is wide, the near-infrared light-emitting material can be perfectly matched with a commercial blue light chip, and the near-infrared light-emitting material is a new type of high-efficiency near-infrared light-emitting material which can be effectively excited by blue light, has good chemical thermal stability and good light-emitting performance.

Description

Technical Field

[0001] This invention relates to the field of luminescent materials technology, specifically to a near-infrared luminescent material, its preparation method, and its applications. Background Technology

[0002] Near-infrared (NIR) light sources possess advantages such as strong penetration, high resolution, and high signal-to-noise ratio, and are widely used in fields such as biological detection, infrared phototherapy, non-invasive detection, military reconnaissance, and food analysis. Currently, NIR light sources include halogen tungsten lamps and AlGaAs light-emitting diodes (LEDs). Considering that different organic groups have different absorption bands, a wider-bandwidth NIR light source is beneficial for obtaining more information.

[0003] Current NIR light sources, such as LEDs and OLEDs, use trivalent chromium ions as the luminescent center, providing broad-spectrum emission from the visible to the near-infrared region. Some research focuses on optimizing the luminous efficiency and color purity of trivalent chromium ions in organic or inorganic matrices. However, the challenge for these materials lies in finding suitable host materials and controlling the concentration quenching effect caused by the aggregation of trivalent chromium ions. Although luminescent materials using trivalent chromium ions as activators have shown great potential in many fields, current technologies still have some limitations. For example, the stability and luminous efficiency of trivalent chromium ions in certain host crystals are insufficient, especially under prolonged or high-power excitation, which may lead to a decline in luminescent performance. Furthermore, the modulation of the emission wavelength of trivalent chromium ions is also a challenge, requiring the selection of host crystals or chemical modification. Therefore, inventing an NIR light source with a wide excitation spectrum and good stability is of great significance. Summary of the Invention

[0004] The purpose of this invention is to provide a near-infrared luminescent material, its preparation method, and its application. The near-infrared luminescent material provided by this invention is suitable for blue light excitation, has a wide excitation spectrum, and good chemical stability.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention provides a near-infrared luminescent material with the chemical formula A3Cr. x TiTaM 3-x O 12 Where A is one or more of Ca, Sr and Ba; M is one or more of Al, Ga and In; 0.01≤x≤0.2.

[0007] Preferably, the chemical formula is Ca3Cr 0.03 TiTaGa 2.97 O 12 Ba3Cr 0.03 TiTaGa 2.97 O12 Sr3Cr 0.03 TiTaGa 2.97 O 12 Ca3Cr 0.04 TiTaGa 2.96 O 12 Ca3Cr 0.04 TiTaIn 2.96 O 12 Ca3Cr 0.02 TiTaGa 2.98 O 12 Ca3Cr 0.02 TiTaIn 2.98 O 12 or Ca3Cr 0.02 TiTaAl 2.98 O 12 .

[0008] Preferably, the particle size of the near-infrared luminescent material is 1–10 μm.

[0009] The present invention also provides a method for preparing the near-infrared luminescent material described in the above technical solution, comprising the following steps:

[0010] The near-infrared luminescent material is obtained by mixing an A-containing compound, a Cr-containing compound, a Ti-containing compound, a Ta-containing compound, and an M-containing compound, and then sequentially pre-calcining and calcining it in an oxygen-containing environment; wherein the A in the A-containing compound is one or more of Ca, Sr, and Ba; and the M in the M-containing compound is one or more of Al, Ga, and In.

[0011] Preferably, the A-containing compound includes one or more of A-containing oxides, A-containing hydroxides, and A-containing salts.

[0012] Preferably, the Cr-containing compound includes one or more of Cr-containing oxides, Cr-containing salts, and Cr-containing hydroxides.

[0013] Preferably, the Ti-containing compound includes one or more of Ti-containing oxides, Ti-containing salts, and Ti-containing hydroxides.

[0014] The Ta-containing compounds include Ta-containing oxides.

[0015] Preferably, the M-containing compound includes one or more of M-containing oxides, M-containing hydroxides, and M-containing salts.

[0016] Preferably, the pre-calcination temperature is 1100–1300°C, and the time is 1–9 hours;

[0017] The calcination temperature is 1200–1400℃, and the time is 7–9 hours.

[0018] The present invention also provides the application of the near-infrared luminescent material described in the above technical solution or the near-infrared luminescent material obtained by the preparation method described in the above technical solution in optical conversion devices.

[0019] This invention provides a near-infrared luminescent material with the chemical formula A3Cr. x TiTaM 3-x O 12 Wherein, A is one or more of Ca, Sr, and Ba; M is one or more of Al, Ga, and In; 0.01 ≤ x ≤ 0.2. This invention uses Cr as an activator, utilizing Cr... 3+ As the luminescent center in the phosphor matrix, it generates near-infrared red light. Furthermore, based on the chemically stable and highly efficient perovskite structure, it utilizes elements such as tantalum, aluminum, gallium, indium, titanium, calcium, barium, and strontium to construct a weak crystal field environment to achieve Cr... 3+ The emission peak is red-shifted to the near-infrared region, exhibiting stable chemical properties and excellent temperature characteristics. The near-infrared luminescent material provided by this invention emits near-infrared red light with a wavelength range of 680–1100 nm when excited by 450 nm blue light, and is suitable for effective excitation by light in the 250–500 nm wavelength range (including near-ultraviolet and blue light). Its wide excitation spectrum range allows for perfect matching with commercial blue light chips, making it suitable for blue LED chips. This near-infrared luminescent material is suitable for high-energy blue light excitation, thus exhibiting good stability and luminous efficiency. Under prolonged or high-power excitation, it maintains its near-infrared phosphor luminescent properties. It is a novel, highly efficient near-infrared luminescent material that can be effectively excited by blue light, possesses good chemical and thermal stability, and exhibits excellent luminescent performance. It has significant application prospects in real-time non-destructive testing fields such as food analysis, biomedical detection, and infrared imaging.

[0020] Furthermore, compared with most existing near-infrared luminescent materials that require sintering in a reducing atmosphere, this invention can obtain near-infrared luminescent materials through low-temperature sintering. It has the advantages of simple preparation method, low equipment requirements, no pollution, readily available raw materials, low price, energy saving and environmental protection, and is practical and suitable for large-scale industrial production. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 The image shows the XRD pattern of the near-infrared luminescent material obtained in Example 1.

[0023] Figure 2 The emission spectrum of the near-infrared luminescent material obtained in Example 1 is shown below.

[0024] Figure 3 The excitation spectrum of the near-infrared luminescent material obtained in Example 1;

[0025] Figure 4 The electroluminescence spectrum of the LED device based on near-infrared luminescent material obtained in Example 1 is shown below.

[0026] Figure 5 This is a color mapping diagram of the emission spectrum of the near-infrared luminescent material obtained in Example 1 at different temperatures. Detailed Implementation

[0027] This invention provides a near-infrared luminescent material with the chemical formula A3Cr. x TiTaM 3-x O 12 Where A is one or more of Ca, Sr and Ba; M is one or more of Al, Ga and In; 0.01≤x≤0.2.

[0028] In this invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art.

[0029] In this invention, A is one or more of Ca, Sr and Ba, preferably Ca or Ba; when A is two or more of the above elements, this invention does not impose any special restrictions on the ratio of the elements, as long as the sum of the atoms of each element in A in the chemical formula is 3.

[0030] In this invention, M is one or more of Al, Ga and In, preferably Al or Ga.

[0031] In this invention, 0.01≤x≤0.2, preferably 0.03≤x≤0.1.

[0032] In this invention, the chemical formula of the near-infrared luminescent material is preferably Ca3Cr. 0.03 TiTaGa 2.97 O 12 Ba3Cr 0.03 TiTaGa 2.97 O 12 Sr3Cr 0.03 TiTaGa 2.97 O 12 Ca3Cr 0.04 TiTaGa 2.96 O 12 Ca3Cr 0.04 TiTaIn 2.96O 12 Ca3Cr 0.02 TiTaGa 2.98 O 12 Ca3Cr 0.02 TiTaIn 2.98 O 12 or Ca3Cr 0.02 TiTaAl 2.98 O 12 .

[0033] In this invention, the particle size of the near-infrared luminescent material is preferably 1 to 10 μm, more preferably 3 to 7 μm.

[0034] The near-infrared luminescent material provided by this invention possesses a broad emission spectrum, covering a wide range from 680 nm to 1100 nm; its effective excitation range is 280–380 nm and 400–470 nm, making it suitable for commercial blue LED chips and highly practical; under 450 nm blue light excitation, it efficiently emits near-infrared light with a peak wavelength of approximately 800 nm and a full width at half maximum (FWHM) of 188 nm, making it suitable as a broadband fluorescent material for near-infrared LEDs with fluorescence conversion; the raw materials for the near-infrared luminescent material provided by this invention are inexpensive and readily available, requiring minimal equipment, and the preparation method and production process are simple, requiring no special reaction equipment, thus facilitating industrial production.

[0035] The present invention also provides a method for preparing the near-infrared luminescent material described in the above technical solution, comprising the following steps:

[0036] The near-infrared luminescent material is obtained by mixing an A-containing compound, a Cr-containing compound, a Ti-containing compound, a Ta-containing compound, and an M-containing compound, and then sequentially pre-calcining and calcining it in an oxygen-containing environment; wherein the A in the A-containing compound is one or more of Ca, Sr, and Ba; and the M in the M-containing compound is one or more of Al, Ga, and In.

[0037] In this invention, the A-containing compound preferably includes one or more of A-containing oxides, A-containing hydroxides, and A-containing salts, more preferably one or more of A-containing oxides, A-containing nitrates, A-containing hydroxides, A-containing oxalates, A-containing halides, and A-containing carbonates, and most preferably A-containing oxides, A-containing hydroxides, or A-containing carbonates; the A-containing oxide is preferably CaO, SrO, or BaO; the A-containing nitrate is preferably Ca(NO3)2, Sr(NO3)2, or Ba(NO3)2; the A-containing hydroxide is preferably Ca(OH)2, Sr(OH)2, or Ba(OH)2; the A-containing halide is preferably CaCl2, SrCl2, or BaCl2; and the A-containing carbonate is preferably CaCO3, SrCO3, or BaCO3.

[0038] In this invention, the Cr-containing compound preferably includes one or more of Cr-containing oxides, Cr-containing salts, and Cr-containing hydroxides, more preferably one or more of Cr-containing oxides, Cr-containing nitrates, Cr-containing carbonates, Cr-containing halides, and Cr-containing hydroxides, and most preferably Cr-containing oxides, Cr-containing hydroxides, or Cr-containing carbonates; the Cr-containing oxide is preferably Cr₂O₃; the Cr-containing nitrate is preferably Cr(NO₃)₃; the Cr-containing carbonate is preferably Cr₂(CO₃)₃; the Cr-containing halide is preferably CrCl₃; the Cr-containing hydroxide is preferably Cr(OH)₃; the molar ratio of Cr in the Cr-containing compound to A in the A-containing compound is preferably 0.01–0.2:3, more preferably 0.03–0.1:3.

[0039] In this invention, the Ti-containing compound preferably includes one or more of Ti-containing oxides, Ti-containing salts, and Ti-containing hydroxides, more preferably one or more of Ti-containing oxides, Ti-containing nitrates, Ti-containing carbonates, Ti-containing halides, and Ti-containing hydroxides, and most preferably Ti-containing oxides, Ti-containing hydroxides, or Ti-containing carbonates; the Ti-containing oxide is preferably TiO2; the Ti-containing nitrate is preferably Ti(NO3)4; the Ti-containing hydroxide is preferably Ti(OH)4; the Ti-containing halide is preferably TiCl2 or TiCl4; the Ti-containing carbonate is preferably TiCO3; the molar ratio of Ti in the Ti-containing compound to A in the A-containing compound is preferably 0.5–2:3, more preferably 0.9–1.2:3.

[0040] In this invention, the Ta-containing compound preferably includes Ta-containing oxides, more preferably tantalum pentoxide and / or tantalum dioxide, and most preferably tantalum pentoxide; the molar ratio of Ta in the Ta-containing compound to A in the A-containing compound is preferably 0.5 to 2:3, more preferably 0.9 to 1.2:3.

[0041] In this invention, the M-containing compound preferably includes one or more of M-containing oxides, M-containing hydroxides, and M-containing salts, more preferably one or more of M-containing oxides, M-containing nitrates, M-containing hydroxides, M-containing oxalates, M-containing halides, and M-containing carbonates, and most preferably M-containing oxides, M-containing hydroxides, or M-containing carbonates; the M-containing oxide is preferably Ga2O3, Al2O3, or In2O3; the M-containing nitrate is preferably Ga(NO3)3, Al(NO3)3, or In(NO3)3; the M-containing hydroxide is preferably Ga(OH)3, Al(OH)3, or In(OH)3; the M-containing halide is preferably GaCl3, AlCl3, or InCl3; the M-containing carbonate is preferably Ga2(CO3)3, Al2(CO3)3, or Al2(CO3)3; the molar ratio of M in the M-containing compound to A in the A-containing compound is preferably 2.8–2.99:3, more preferably 2.9–2.97:3.

[0042] In this invention, the mixing is preferably grinding and mixing; this invention does not have a special limitation on the grinding and mixing process, and the materials can be mixed evenly in a manner known in the art.

[0043] In this invention, the oxygen-containing environment is preferably air; the pre-calcination temperature is preferably 1100-1300℃, more preferably 1150-1250℃; the time is preferably 1-9h, more preferably 1-5h; and the pre-calcination is preferably carried out in a box-type high-temperature furnace.

[0044] In this invention, the process of grinding and mixing is preferably included before calcination; the present invention does not have any special limitations on the grinding and mixing process, and the materials can be mixed evenly in a manner known in the art.

[0045] In this invention, the calcination temperature is preferably 1200-1400℃, more preferably 1300-1350℃; the time is preferably 7-9h, more preferably 7.5-8.5h; and the calcination is preferably carried out in a box-type high-temperature furnace.

[0046] In this invention, the calcination process preferably includes grinding and dispersion; the present invention does not have a special limitation on the grinding and dispersion process, and a uniformly dispersed product can be obtained by means of methods known in the art.

[0047] The preparation method provided by this invention can obtain near-infrared luminescent materials through low-temperature sintering. It has the advantages of simple preparation method, low equipment requirements, no pollution, easy availability of raw materials, low price, energy saving and environmental protection. It is practical and suitable for large-scale industrial production.

[0048] The present invention also provides the application of the near-infrared luminescent material described in the above technical solution or the near-infrared luminescent material obtained by the preparation method described in the above technical solution in optical conversion devices.

[0049] In this invention, the light conversion device is preferably an LED device; the LED device is preferably a near-infrared LED device; the near-infrared LED device preferably includes a near-infrared luminescent material and a blue LED chip; the near-infrared luminescent material is the near-infrared luminescent material described in the above technical solution or the near-infrared luminescent material obtained by the preparation method described in the above technical solution.

[0050] The present invention does not impose any special limitations on the application process, and any method known to those skilled in the art can be used.

[0051] To further illustrate the present invention, the near-infrared luminescent materials, their preparation methods, and applications provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0052] Example 1

[0053] Using calcium carbonate, titanium dioxide, chromium trioxide, gallium trioxide, and tantalum pentoxide as starting materials, and according to the molar ratio of each element Ca:Ti:Cr:Ga:Ta = 3:1:0.03:2.97:1, corresponding to x = 0.03, five raw materials were weighed out, and the total weight of the raw material mixture was 20g. The mixture was thoroughly ground and mixed, then placed in a box-type high-temperature furnace. The mixture was calcined in air at a temperature of 1200℃ for 1 hour. After cooling to room temperature, it was thoroughly ground and mixed evenly, and then calcined again in air at a temperature of 1360℃ for 8 hours. After cooling, it was ground to obtain the near-infrared luminescent material Ca3Cr. 0.03 TiTaGa 2.97 O 12 The X-ray diffraction pattern, excitation spectrum, and emission spectrum of the obtained near-infrared luminescent material are shown in [reference needed]. Figures 1-3 .

[0054] Depend on Figure 1 As can be seen, the X-ray powder diffraction pattern of the prepared near-infrared luminescent material shows that the prepared sample is a single pure phase with high crystallinity.

[0055] Depend on Figure 2 As can be seen, the excitation spectrum test results of the near-infrared luminescent material obtained at a monitoring wavelength of 800 nm show that the sample can be well excited under ultraviolet light at 450 nm.

[0056] Depend on Figure 3As can be seen, the emission spectrum of the prepared near-infrared luminescent material at an excitation wavelength of 450 nm shows that the sample can emit near-infrared light with wavelengths in the range of 690–1100 nm.

[0057] The near-infrared luminescent material obtained in this embodiment was excited under a 450nm blue LED chip, and the fluorescence spectrum was measured. The detection results are as follows: Figure 4 As shown in the figure, the results reveal that various current spectra indicate increased intensity and a wider emission bandwidth with increasing current. These results highlight the robustness of the phosphor under stress thermal conditions and its promising future applications in NIR-LEDs. NIR-LEDs are widely used to solve challenging night vision and bioimaging tasks.

[0058] The color mapping of the emission spectrum of the near-infrared luminescent material obtained in this embodiment at different temperatures was tested, and the detection results are as follows: Figure 5 As shown in the figure. The results indicate that the PL intensity generally decreases with increasing temperature in this embodiment. At 150°C, the PL intensity is retained by 41.3% compared to 25°C, indicating that the near-infrared luminescent material obtained in this embodiment has good thermal stability in practical applications.

[0059] Example 2

[0060] Using barium carbonate, titanium dioxide, chromium trioxide, gallium trioxide, and tantalum pentoxide as starting materials, and according to the molar ratio of Ba:Ti:Cr:Ga:Ta = 3:1:0.03:2.97:1 (corresponding to x = 0.03), five raw materials were weighed out, and the total weight of the raw material mixture was 20g. The mixture was thoroughly ground and mixed, then placed in a box-type high-temperature furnace. The mixture was calcined in air at 1200℃ for 1 hour. After cooling to room temperature, it was thoroughly ground and mixed evenly, and then calcined again in air at 1360℃ for 8 hours. After cooling, it was ground to obtain the near-infrared luminescent material Ba3Cr. 0.03 TiTaGa 2.97 O 12 .

[0061] Example 3

[0062] Using strontium carbonate, titanium dioxide, chromium trioxide, gallium trioxide, and tantalum pentoxide as starting materials, and according to the molar ratio of each element Sr:Ti:Cr:Ga:Ta = 3:1:0.03:2.97:1 (corresponding to x = 0.03), five raw materials were weighed out, and the total weight of the raw material mixture was 20g. The mixture was thoroughly ground and mixed, then placed in a box-type high-temperature furnace. The mixture was calcined in air at a temperature of 1200℃ for 1 hour. After cooling to room temperature, it was thoroughly ground and mixed evenly, and then calcined again in air at a temperature of 1360℃ for 8 hours. After cooling, it was ground to obtain the near-infrared luminescent material Sr3Cr.0.03 TiTaGa 2.97 O 12 .

[0063] Example 4

[0064] Starting with calcium carbonate, titanium dioxide, chromium trioxide, gallium trioxide, and tantalum pentoxide, and according to the molar ratio of each element Ca:Ti:Cr:Ga:Ta = 3:1:0.04:2.96:1 (corresponding to x = 0.04), five raw materials were weighed out, and the total weight of the mixture was 20g. The mixture was thoroughly ground and mixed, then placed in a box-type high-temperature furnace. The mixture was calcined in air at 1200℃ for 1 hour. After cooling to room temperature, it was thoroughly ground and mixed evenly, and then calcined again in air at 1360℃ for 8 hours. After cooling, it was ground to obtain the near-infrared luminescent material Ca3Cr. 0.04 TiTaGa 2.96 O 12 .

[0065] Example 5

[0066] Starting with calcium carbonate, titanium dioxide, chromium trioxide, indium trioxide, and tantalum pentoxide, and according to the molar ratio of each element Ca:Ti:Cr:In:Ta = 3:1:0.04:2.96:1 (corresponding to x = 0.04), five raw materials were weighed out, and the total weight of the mixture was 20g. The mixture was thoroughly ground and mixed, then placed in a box-type high-temperature furnace. The mixture was calcined in air at 1200℃ for 1 hour. After cooling to room temperature, it was thoroughly ground and mixed evenly, and then calcined again in air at 1360℃ for 8 hours. After cooling, it was ground to obtain the near-infrared luminescent material Ca3Cr. 0.04 TiTaIn 2.96 O 12 .

[0067] Example 6

[0068] Using calcium carbonate, titanium dioxide, chromium trioxide, gallium trioxide, and tantalum pentoxide as starting materials, and according to the molar ratio of each element Ca:Ti:Cr:Ga:Ta = 3:1:0.02:2.98:1, corresponding to x = 0.02, five raw materials were weighed out, and the total weight of the raw material mixture was 20g. The mixture was thoroughly ground and mixed, then placed in a box-type high-temperature furnace. The mixture was calcined in air at a temperature of 1200℃ for 1 hour. After cooling to room temperature, it was thoroughly ground and mixed evenly, and then calcined again in air at a temperature of 1360℃ for 8 hours. After cooling, it was ground to obtain the near-infrared luminescent material Ca3Cr. 0.02 TiTaGa 2.98 O12 .

[0069] Example 7

[0070] Using calcium carbonate, titanium dioxide, chromium trioxide, indium trioxide, and tantalum pentoxide as starting materials, and according to the molar ratio of each element Ca:Ti:Cr:In:Ta = 3:1:0.02:2.98:1, corresponding to x = 0.02, five raw materials were weighed out, and the total weight of the raw material mixture was 20g. The mixture was thoroughly ground and mixed, then placed in a box-type high-temperature furnace. The mixture was calcined in air at a temperature of 1200℃ for 1 hour. After cooling to room temperature, it was thoroughly ground and mixed evenly, and then calcined again in air at a temperature of 1360℃ for 8 hours. After cooling, it was ground to obtain the near-infrared luminescent material Ca3Cr. 0.02 TiTaIn 2.98 O 12 .

[0071] Example 8

[0072] Using calcium carbonate, titanium dioxide, chromium trioxide, aluminum trioxide, and tantalum pentoxide as starting materials, and according to the molar ratio of each element Ca:Ti:Cr:Al:Ta = 3:1:0.02:2.98:1, corresponding to x = 0.02, five raw materials were weighed out, and the total weight of the raw material mixture was 20g. The mixture was thoroughly ground and mixed, then placed in a box-type high-temperature furnace. The mixture was calcined in air at a temperature of 1200℃ for 1 hour. After cooling to room temperature, it was thoroughly ground and mixed evenly, and then calcined again in air at a temperature of 1360℃ for 8 hours. After cooling, it was ground to obtain the near-infrared luminescent material Ca3Cr. 0.02 TiTaAl 2.98 O 12 .

[0073] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A near-infrared luminescent material, characterized in that, The chemical formula is A3Cr x TiTaM 3-x O 12 Where A is one or more of Ca, Sr and Ba; M is Ga; 0.01≤x≤0.

2.

2. The near-infrared luminescent material according to claim 1, characterized in that, Chemistry is Ca3Cr 0.03 TiTaGa 2.97 SHE 12 、Ba3Cr 0.03 TiTaGa 2.97 SHE 12 、Sr3Cr 0.03 TiTaGa 2.97 SHE 12 、Ca3Cr 0.04 TiTaGa 2.96 SHE 12 Or Ca3Cr 0.02 TiTaGa 2.98 SHE 12 。 3. The near-infrared luminescent material according to claim 1, characterized in that, The particle size of the near-infrared luminescent material is 1~10μm.

4. A method for preparing the near-infrared luminescent material according to any one of claims 1 to 3, characterized in that, Includes the following steps: The near-infrared luminescent material is obtained by mixing compounds containing A, Cr, Ti, Ta, and M, and then sequentially pre-calcining and calcining them in an oxygen-containing environment. The A in the A-containing compound is one or more of Ca, Sr, and Ba; the M in the M-containing compound is Ga.

5. The preparation method according to claim 4, characterized in that, The A-containing compound includes one or more of A-containing oxides, A-containing hydroxides, and A-containing salts.

6. The preparation method according to claim 4, characterized in that, The Cr-containing compounds include one or more of Cr-containing oxides, Cr-containing salts, and Cr-containing hydroxides.

7. The preparation method according to claim 4, characterized in that, The Ti-containing compound includes one or more of Ti-containing oxides, Ti-containing salts, and Ti-containing hydroxides; The Ta-containing compounds include Ta-containing oxides.

8. The preparation method according to claim 4, characterized in that, The M-containing compound includes one or more of M-containing oxides, M-containing hydroxides, and M-containing salts.

9. The preparation method according to claim 4, characterized in that, The pre-calcination temperature is 1100~1300℃, and the time is 1~9h; The calcination temperature is 1200~1400℃, and the time is 7~9h.

10. The application of the near-infrared luminescent material according to claim 1 or 2 or the near-infrared luminescent material obtained by the preparation method according to any one of claims 3 to 9 in optical conversion devices.

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