A broadband near-infrared luminescent material, its preparation method, and a near-infrared LED light source

Abstract

The present invention discloses a broadband near-infrared luminescent material, a preparation method thereof, and a near-infrared LED light source, belonging to the technical field of near-infrared luminescent materials. The broadband near-infrared luminescent material provided by the present invention has a structure shown in formula (I), Ca 4‑x Zn x HfGe3O 12 :yCr 3+ Formula (I), wherein 0 < x ≤ 1, 0.01 ≤ y ≤ 0.10. By substituting Zn 2+ for Ca 2+ , the problem of lattice mismatch is solved, and the luminous intensity and thermal stability are simultaneously improved. The method is simple and "brings three benefits at one stroke"; it can absorb blue light in the range of 400-550 nm and obtain a broadband near-infrared emission with an emission peak range of 650-1200 nm under the excitation of 470 nm; it has a long emission wavelength (>800 nm), high efficiency (high IQE, EQE and AE values), and high thermal stability. The integrated intensity can still maintain more than 80% of room temperature at a high temperature of 400 K, and has great application potential in night vision, biological imaging, rapid recognition and other aspects.

Description

Technical Field

[0001] This invention relates to the field of near-infrared luminescent materials technology, and in particular to a broadband near-infrared luminescent material, its preparation method, and a near-infrared LED light source. Background Technology

[0002] The information disclosed in the background section of this invention is intended only to enhance the understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Near-infrared (NIR) luminescent materials are playing an increasingly important role in agriculture, industry, retail, and biomedical health. Traditional infrared light sources such as halogen tungsten lamps and continuous-wave lasers suffer from drawbacks such as large size and low efficiency, failing to meet the demands of integrated, portable commercial applications. Inspired by white light-emitting diode (LED) technology, near-infrared phosphor-converted LEDs (NIR pc-LEDs) have a broader application prospect due to their advantages such as small size, high efficiency, and tunable emission peak position, allowing for easy integration into smartphones and wearable electronic devices. Near-infrared luminescent materials, as an essential component of NIR pc-LEDs, play a crucial role in the performance of the device. Therefore, developing near-infrared luminescent materials with high efficiency and high thermal stability has become an urgent problem to be solved.

[0004] Cr 3+ Activated garnet-structured near-infrared luminescent materials have attracted considerable attention due to their unique luminescent properties and abundant cation sites. Ideal garnet belongs to the Ia-3d space group of the cubic crystal system and has the chemical formula A3B2C3O. 12 However, a large number of reported Cr 3+ Activated garnet-type near-infrared luminescent materials exhibit unsatisfactory internal quantum efficiency (IQE) and thermal stability, or emit extremely short wavelengths, typically less than 760 nm, limiting their applications. Furthermore, the three-dimensional rigid structure of garnet exacerbates the degradation of Cr... 3+ The dd-forbidden transitions in garnet-type near-infrared luminescent materials result in generally low absorption efficiency (AE), leading to a widespread problem of low external quantum yield (EQE). Therefore, there is an urgent need to develop highly efficient (high IQE and EQE) and thermally stable garnet-type near-infrared luminescent materials with long emission wavelengths (>800 nm).

[0005] Sheng Xingxing et al. (Journal of Inorganic Chemistry, February 2024, Vol. 40, No. 2) reported a broadband near-infrared Ca4HfGe3O 12 :xCr 3+ (0≤x≤0.09) phosphors were studied, and their luminescent properties and thermal stability were investigated. However, the inventors discovered that, due to... and The significant mismatch between ions at the B site results in unsatisfactory luminescence intensity and thermal stability. Therefore, how to further improve the luminescence intensity and thermal stability of Ca4HfGe3O through structural design is a key challenge. 12 :xCr 3+ The luminescence intensity and thermal stability of phosphors (0≤x≤0.09) are problems that urgently need to be solved. Summary of the Invention

[0006] In view of this, the present invention provides a broadband near-infrared luminescent material, its preparation method, and a near-infrared LED light source, solving the problem of Ca4HfGe3O in the prior art. 12 :xCr 3+ (0≤x≤0.09) The problem of unsatisfactory luminescence intensity and thermal stability of phosphors is addressed by providing broadband near-infrared luminescent materials with excellent luminescence intensity and thermal stability, as well as high internal and external quantum yields.

[0007] In a first aspect, the present invention provides a broadband near-infrared luminescent material having the structure shown in formula (I), Ca 4- x Zn x HfGe3O 12 :yCr 3+ Equation (I), where 0 <x≤1,0.01≤y≤0.10。

[0008] This invention is achieved through Replace Ca4HfGe3O 12 :xCr 3+ Ca in (0≤x≤0.09) 2+ Site reconstruction was performed to make Ca4HfGe3O 12 :Cr 3+ To Ca3ZnHfGe3O 12 :Cr 3+ Transformation, thereby promoting Cr 3+ It is easier for Zn to enter the crystal lattice. 2+ The introduction of ions transforms the B site from CaO6 to Zn / CaO6, increasing atomic disorder and lattice distortion, promoting the disruption of dd-forbidden transitions, and thus improving luminescence efficiency; simultaneously, it also affects the chromium content. 3+ -O 2- The reduced bond length improves the structural stiffness and thermal stability.

[0009] The broadband near-infrared luminescent material provided by this invention absorbs blue light in the range of 400-550nm and emits broadband near-infrared light with an emission peak range of 650-1200nm, exhibiting excellent luminescent performance.

[0010] For the atomic ratio of elements in formula (I), preferably, 0.4 ≤ x ≤ 1, and further, x is 0.8. When x = 0.8, the broadband near-infrared luminescent material has the optimal luminescence intensity and excellent thermal stability. At 400K, the integrated intensity of the material is more than 85% of that at room temperature, and the emission wavelength remains at 800nm, exhibiting a long emission wavelength.

[0011] For the atomic ratio of elements in formula (I), preferably, 0.03 ≤ y ≤ 0.10, and further, y is 0.07. The material exhibits optimal luminescence intensity at y = 0.07.

[0012] Preferably, the near-infrared luminescent material has the structural formula Ca3Zn. 0.8 HfGe3O 12 0.07Cr 3+ This broadband near-infrared luminescent material exhibits excellent performance, with high luminescence intensity, high internal quantum yield, high external quantum yield, and high absorption efficiency (IQE = 92%, AE = 31%, EQE = 29%).

[0013] Secondly, the present invention provides a method for preparing the above-mentioned broadband near-infrared luminescent material, comprising the following steps:

[0014] The Ca-source compound, Zn-source compound, Hf-source compound, Ge-source compound, and Cr-source compound were mixed to obtain a mixture;

[0015] The mixture is then sintered to obtain the final product.

[0016] Preferably, the Ca source compound is a compound containing the element Ca, selected from one or more of Ca carbonates, nitrates, phosphates, oxides, fluorides, and chlorides; in a preferred embodiment, the Ca source compound is CaCO3.

[0017] Preferably, the Zn source compound is a compound containing Zn, selected from one or more of Zn oxides, hydroxides, acetates, carbonates, phosphates, and nitrates; in a preferred embodiment, the Zn source compound is ZnO.

[0018] Preferably, the Hf source compound is a compound containing the Hf element, selected from one or more of Hf nitrates, phosphates, oxides, and fluorides; in a preferred embodiment, the Hf source compound is HfO2.

[0019] Preferably, the Ge source compound is a compound containing the element Ge, selected from one or more of Ge nitrates, phosphates, oxides, and fluorides; in a preferred embodiment, the Ge source compound is GeO2.

[0020] Preferably, the Cr source compound is a Cr-containing compound selected from one or more of Cr nitrates, phosphates, oxides, and chlorides; in a preferred embodiment, the Cr source compound is Cr2O3.

[0021] Preferably, the mixture of the present invention further includes boric acid, and the amount of boric acid added is 0.5 to 2 wt% of the total mass of the Ca source compound, Zn source compound, Hf source compound, Ge source compound, and Cr source compound. Boric acid acts as a flux, improving the crystallinity of the product and facilitating the preparation of a pure phase. The preferred method for mixing the above raw materials in the present invention is grinding and mixing, that is, placing the weighed raw materials into a mortar and mixing them with a certain amount of anhydrous ethanol, and grinding thoroughly to obtain a powdered mixture.

[0022] Preferably, the sintering temperature is 1200–1500°C, and the sintering time is 5–8 hours. After the above sintering, the present invention preferably further performs a grinding post-processing to grind the sample into powder to obtain a broadband near-infrared luminescent material product having the structure shown in formula (I).

[0023] The present invention obtains a broadband near-infrared luminescent material by performing appropriate powder processing to obtain a phosphor that meets the requirements of LED packaging (uniform particle size and excellent luminous intensity). The present invention does not impose any special restrictions on the powder processing method, and any conventional processing method for preparing packaged LED phosphors in the field is acceptable, such as wet ball milling (crushing), particle size monitoring, and post-processing such as passing through a screen.

[0024] The present invention also provides a near-infrared LED light source, comprising a blue light chip and a light-emitting material for LED packaging; the light-emitting material is the broadband near-infrared light-emitting material described above.

[0025] Compared with the prior art, the present invention has achieved the following beneficial effects:

[0026] This invention provides a broadband near-infrared luminescent material having the structure shown in formula (I), using Zn 2+ For Ca 2+ This invention replaces the lattice mismatch, simultaneously improving luminescence intensity and thermal stability in a simple, "three-in-one" manner. It can absorb blue light in the 400–550 nm range and, under 470 nm excitation, achieves broadband near-infrared emission with an emission peak range of 650–1200 nm. It possesses long emission wavelengths (>800 nm), high efficiency (high IQE, EQE, and AE values), and high thermal stability; even at 400 K, its integrated intensity remains above 80% of its room temperature value, demonstrating significant application potential in night vision, bioimaging, and rapid identification. The broadband near-infrared luminescent material of this invention is prepared using a traditional solid-state method, thus offering advantages such as high product crystallinity and ease of mass production. Attached Figure Description

[0027] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation thereof. Obviously, those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0028] Figure 1 These are X-ray diffraction patterns obtained from the broadband near-infrared luminescent materials obtained in Examples 1-5 and Comparative Example 1 of this invention;

[0029] Figure 2 These are the emission spectra of the broadband near-infrared luminescent materials of Examples 1-5 and Comparative Example 1 of the present invention at an excitation wavelength of 470 nm;

[0030] Figure 3 These are the curves showing the relative integral intensity versus temperature of the broadband near-infrared luminescent materials obtained in Examples 1-5 and Comparative Example 1 of this invention.

[0031] Figure 4 These are the emission spectra of the broadband near-infrared luminescent materials obtained in Examples 4, 6-9 of this invention under 470 nm excitation;

[0032] Figure 5 Figure A shows the quantum yield test results of Embodiment 4 of the present invention. Figure B shows the obtained quantum yield test curve and the specific values ​​of IQE, AE, and EQE. Detailed Implementation

[0033] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0034] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0035] Example 1

[0036] This embodiment provides Ca 3.8 Zn 0.2 HfGe3O 12 0.03Cr 3+ The preparation method (i.e., x = 0.2, y = 0.03).

[0037] To prepare 1.5 mmol of the target product, weigh 0.5705 g of CaCO3, 0.0244 g of ZnO, 0.3157 g of HfO2, 0.4709 g of GeO2, and 0.0034 g of Cr2O3, with a total mass of 1.384 g for the mixed compounds. Then add 0.0138 g of H3BO3. 3， The mixture was placed in a mortar and mixed with 15 mL of anhydrous ethanol, and then ground thoroughly until dry to obtain a powder. The resulting powder was placed in an alumina crucible and heated in air to 1350 °C, maintaining this temperature for 6 hours. After cooling to room temperature, the calcined sample was removed and ground to obtain the product with the chemical formula Ca. 3.8 Zn 0.2 HfGe3O 12 0.03Cr 3+ Broadband near-infrared luminescent materials.

[0038] Example 2

[0039] This embodiment provides Ca 3.6 Zn 0.4 HfGe3O 12 0.03Cr 3+ The preparation method (i.e., x = 0.4, y = 0.03).

[0040] To prepare 1.5 mmol of the target product, 0.5405 g of CaCO3, 0.0488 g of ZnO, 0.3157 g of HfO2, 0.4709 g of GeO2, and 0.0034 g of Cr2O3 were weighed, with a total mass of 1.379 g. 0.0138 g of H3BO3 was then added and placed in a mortar with 15 mL of anhydrous ethanol. The mixture was thoroughly ground until dry to obtain a powder. The resulting powder was placed in an alumina crucible and heated in air to 1350 °C for 6 hours. After cooling to room temperature, the calcined sample was removed and ground to obtain the product with the chemical formula Ca. 3.6 Zn 0.4 HfGe3O 12 0.03Cr 3+ Broadband near-infrared luminescent materials.

[0041] Example 3

[0042] This embodiment provides Ca 3.4 Zn 0.6 HfGe3O 12 0.03Cr 3+ The preparation method (i.e., x = 0.6, y = 0.03).

[0043] To prepare 1.5 mmol of the target product, 0.5105 g of CaCO3, 0.0733 g of ZnO, 0.3157 g of HfO2, 0.4709 g of GeO2, and 0.0034 g of Cr2O3 were weighed, with a total mass of 1.374 g. Then, 0.0137 g of H3BO3 was added and placed in a mortar with 15 mL of anhydrous ethanol. The mixture was thoroughly ground until dry to obtain a powder. The resulting powder was placed in an alumina crucible and heated in air to 1350 °C for 6 hours. After cooling to room temperature, the calcined sample was removed and ground to obtain the product with the chemical formula Ca. 3.4 Zn 0.6 HfGe3O 12 0.03Cr 3+ Broadband near-infrared luminescent materials.

[0044] Example 4

[0045] This embodiment provides Ca 3.2 Zn 0.8 HfGe3O 12 0.03Cr 3+ The preparation method (i.e., x = 0.8, y = 0.03).

[0046] To prepare 1.5 mmol of the target product, 0.4804 g of CaCO3, 0.0977 g of ZnO, 0.3157 g of HfO2, 0.4709 g of GeO2, and 0.0034 g of Cr2O3 were weighed, with a total mass of 1.368 g. 0.0137 g of H3BO3 was then added and placed in a mortar with 15 mL of anhydrous ethanol. The mixture was thoroughly ground until dry to obtain a powder. The resulting powder was placed in an alumina crucible and heated in air to 1350 °C for 6 hours. After cooling to room temperature, the calcined sample was removed and ground to obtain the product with the chemical formula Ca. 3.2 Zn 0.8 HfGe3O 12 0.03Cr 3+ Broadband near-infrared luminescent materials.

[0047] Example 5

[0048] This embodiment provides Ca3ZnHfGe3O 12 0.03Cr 3+ The preparation method (i.e., x = 1, y = 0.03).

[0049] To prepare 1.5 mmol of the target product, 0.4504 g of CaCO3, 0.1221 g of ZnO, 0.3157 g of HfO2, 0.4709 g of GeO2, and 0.0034 g of Cr2O3 were weighed, with a total mass of 1.363 g. Then, 0.0136 g of H3BO3 was added and placed in a mortar with 15 mL of anhydrous ethanol. The mixture was thoroughly ground until dry to obtain a powder. The resulting powder was placed in an alumina crucible and heated to 1350 °C in air for 6 hours. After cooling to room temperature, the calcined sample was removed and ground to obtain the product with the chemical formula Ca3ZnHfGe3O. 12 0.03Cr 3+ Broadband near-infrared luminescent materials.

[0050] Example 6

[0051] This embodiment provides Ca 3.2 Zn 0.8 HfGe3O 12 0.01Cr 3+ The preparation method (i.e., x = 0.8, y = 0.01).

[0052] To prepare 1.5 mmol of the target product, 0.4804 g of CaCO3, 0.0977 g of ZnO, 0.3157 g of HfO2, 0.4709 g of GeO2, and 0.0011 g of Cr2O3 were weighed, with a total mass of 1.366 g. Then, 0.0137 g of H3BO3 was added and placed in a mortar with 15 mL of anhydrous ethanol. The mixture was thoroughly ground until dry to obtain a powder. The resulting powder was placed in an alumina crucible and heated in air to 1350 °C for 6 hours. After cooling to room temperature, the calcined sample was removed and ground to obtain the product with the chemical formula Ca. 3.2 Zn 0.8 HfGe3O 12 0.01Cr 3+ Broadband near-infrared luminescent materials.

[0053] Example 7

[0054] This embodiment provides Ca 3.2 Zn 0.8 HfGe3O 12 0.05Cr 3+ The preparation method (i.e., x = 0.8, y = 0.05).

[0055] To prepare 1.5 mmol of the target product, 0.4804 g of CaCO3, 0.0977 g of ZnO, 0.3157 g of HfO2, 0.4709 g of GeO2, and 0.0057 g of Cr2O3 were weighed, with a total mass of 1.370 g. Then, 0.0137 g of H3BO3 was added and placed in a mortar with 15 mL of anhydrous ethanol. The mixture was thoroughly ground until dry to obtain a powder. The resulting powder was placed in an alumina crucible and heated in air to 1350 °C for 6 hours. After cooling to room temperature, the calcined sample was removed and ground to obtain the product with the chemical formula Ca. 3.2 Zn 0.8 HfGe3O 12 0.05Cr 3+ Broadband near-infrared luminescent materials.

[0056] Example 8

[0057] This embodiment provides Ca 3.2 Zn 0.8 HfGe3O 12 0.07Cr 3+ The preparation method (i.e., x = 0.8, y = 0.07).

[0058] To prepare 1.5 mmol of the target product, 0.4804 g of CaCO3, 0.0977 g of ZnO, 0.3157 g of HfO2, 0.4709 g of GeO2, and 0.0079 g of Cr2O3 were weighed, with a total mass of 1.373 g. Then, 0.0137 g of H3BO3 was added and placed in a mortar with 15 mL of anhydrous ethanol. The mixture was thoroughly ground until dry to obtain a powder. The resulting powder was placed in an alumina crucible and heated in air to 1350 °C for 6 hours. After cooling to room temperature, the calcined sample was removed and ground to obtain the product with the chemical formula Ca. 3.2 Zn 0.8 HfGe3O 12 0.07Cr 3+ Broadband near-infrared luminescent materials.

[0059] Example 9

[0060] This embodiment provides Ca 3.2 Zn 0.8 HfGe3O 12 0.1Cr 3+ The preparation method (i.e., x = 0.8, y = 0.1).

[0061] To prepare 1.5 mmol of the target product, a mixture of 0.4804 g CaCO3, 0.0977 g ZnO, 0.3157 g HfO2, 0.4709 g GeO2, and 0.0110 g Cr2O3 (total mass 1.376 g) was weighed. 0.0138 g H3BO3 was added and placed in a mortar with 15 mL of anhydrous ethanol. The mixture was then thoroughly ground until dry to obtain a powder. The resulting powder was placed in an alumina crucible and heated in air to 1350 °C for 6 hours. After cooling to room temperature, the calcined sample was removed and ground to obtain the product with the chemical formula Ca2O3. 3.2 Zn 0.8 HfGe3O 12 0.1Cr 3+ Broadband near-infrared luminescent materials.

[0062] Comparative Example 1

[0063] This comparative example provides Ca4HfGe3O 12 0.03Cr 3+ The preparation method (i.e., x = 0, y = 0.03).

[0064] To prepare 1.5 mmol of the target product, 0.5999 g of CaCO3, 0.3157 g of HfO2, 0.4709 g of GeO2, and 0.0034 g of Cr2O3 were weighed, with a total mass of 1.3899 g. Then, 0.0139 g of H3BO3 was added and placed in a mortar with 15 mL of anhydrous ethanol. The mixture was thoroughly ground until dry to obtain a powder. The resulting powder was placed in an alumina crucible and heated to 1350 °C in air for 6 hours. After cooling to room temperature, the calcined sample was removed and ground to obtain the product with the chemical formula Ca4HfGe3O. 12 0.03Cr 3+ Broadband near-infrared luminescent materials.

[0065] X-ray diffraction patterns of the broadband near-infrared luminescent materials obtained in Examples 1-5 and Comparative Example 1 are shown below. Figure 1 Introducing Zn 2+ The large-angle shift of the X-ray diffraction peaks of the ionic material samples (Examples 1-4) proves that Zn 2+ The ions were successfully incorporated and eventually replaced the final product Ca3ZnHfGe3O. 12 0.03Cr 3+ (Example 5) is a pure phase garnet structure. Figure 2 The emission spectra of the broadband near-infrared luminescent materials in Examples 1-5 and Comparative Example 1 were obtained at an excitation wavelength of 470 nm. Figure 2 From this, we can know that Zn 2+The introduction of ions caused a slight blue shift in the emission peak from 834 nm to 806 nm. The material in Example 4 (x = 0.8) had the strongest luminescence intensity, which was 1.8 times the integrated intensity of Comparative Example 1 (x = 0). Figure 3 The curves showing the relative integrated intensity versus temperature of the broadband near-infrared luminescent materials obtained in Examples 1-5 and Comparative Example 1 are shown. Figure 3 It can be seen that Zn 2+ The gradual introduction of ions compared to the absence of Zn 2+ The ionic material improved the thermal stability of the broadband near-infrared luminescent material. With increasing substitution, the stability increased from 59%@425K (Comparative Example 1, x = 0) to 81%@425K (Example 4, x = 0.8) and 88%@425K (Example 5, x = 1). Note: 88%@425K indicates that the integrated intensity of the material at 425K is 88% of the integrated intensity at room temperature.

[0066] The emission spectra of the broadband near-infrared luminescent materials obtained in Examples 4, 6-9 under 470 nm excitation are as follows: Figure 4 As shown, it can be seen that the strongest luminescence is observed in Example 8 (y = 0.07); Figure 5 As shown, the material Ca in Example 8 3.2 Zn 0.8 HfGe3O 12 0.07Cr 3+ It has an internal quantum yield (IQE) of 92%, an absorption efficiency (AE) of 31%, and an external quantum yield (EQE) of 29%, exhibiting excellent luminescence properties.

[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A broadband near-infrared luminescent material, characterized in that, It has the chemical formula shown in formula (I). Ca 4-x Zn x HfGe3O 12 :yCr 3+ Equation (I), where 0 <x≤1,0.01≤y≤0.10。 2. The broadband near-infrared luminescent material as described in claim 1, characterized in that, 0.4≤x≤1。 3. The broadband near-infrared luminescent material as described in claim 1, characterized in that, 0.03≤y≤0.10。 4. The broadband near-infrared luminescent material as described in claim 1, characterized in that, x is 0.8 and y is 0.

07.

5. The method for preparing the broadband near-infrared luminescent material according to any one of claims 1 to 4, characterized in that, Includes the following steps: The Ca-source compound, Zn-source compound, Hf-source compound, Ge-source compound, and Cr-source compound were mixed to obtain a mixture; The mixture is then sintered to obtain the final product.

6. The preparation method according to claim 5, characterized in that, The Ca source compound is a compound containing the element Ca, selected from one or more of Ca carbonates, nitrates, phosphates, oxides, fluorides, and chlorides; The Zn source compound is a compound containing Zn, selected from one or more of Zn oxides, hydroxides, acetates, carbonates, phosphates, and nitrates; The Hf source compound is a compound containing the Hf element, selected from one or more of Hf nitrates, phosphates, oxides, and fluorides; The Ge source compound is a compound containing the element Ge, selected from one or more of Ge nitrates, phosphates, oxides, and fluorides. The Cr source compound is a compound containing the element Cr, selected from one or more of Cr nitrates, phosphates, oxides, and chlorides.

7. The preparation method according to claim 6, characterized in that, The Ca source compound is CaCO3, the Zn source compound is ZnO, the Hf source compound is HfO2, the Ge source compound is GeO2, and the Cr source compound is Cr2O3.

8. The preparation method according to claim 5, characterized in that, The mixture also includes boric acid, and the amount of boric acid added is 0.5 to 2 wt% of the total mass of the Ca source compound, Zn source compound, Hf source compound, Ge source compound and Cr source compound.

9. The preparation method according to claim 5, characterized in that, The sintering temperature is 1200~1500℃, and the sintering time is 5~8h.

10. A near-infrared LED light source, characterized in that, It includes a blue light chip and a light-emitting material for LED packaging; the light-emitting material is the broadband near-infrared light-emitting material according to any one of claims 1 to 4.

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