Niobium-based near-infrared fluorescent material with ultra-wide spectrum

Abstract

The invention relates to a niobium-based near-infrared fluorescent material with an ultra-wide spectrum, which belongs to the field of near-infrared fluorescent materials and can be represented by a chemical formula shown in the specification, and x is more than 0 and less than or equal to 0.1. When the niobium-based near-infrared fluorescent material with the ultra-wide spectrum is excited by blue light with the wavelength of 455 nm, the main peak of the emission spectrum is located at 940-970 nm, the full width at half maximum of the emission spectrum ranges from 350 nm to 380 nm, and the internal quantum efficiency ranges from 50% to 75%, so that the fluorescent material can be applied to packaging of near-infrared LED devices.

Description

Technical Field

[0001] This invention relates to the field of near-infrared fluorescent materials, and more particularly to a niobium-based near-infrared fluorescent material with an ultra-wide spectrum, its preparation method, and its applications. Background Technology

[0002] Near-infrared spectroscopy equipment has been widely used in non-destructive food testing, non-invasive medical diagnosis, and bioimaging technologies. In recent years, near-infrared spectroscopy equipment has been developing towards portability, and developing compact, efficient, and high-output-power near-infrared light sources is a prerequisite for achieving this goal. Fluorescent material conversion near-infrared LEDs are currently considered ideal near-infrared light sources due to their small size and tunable emission spectrum. In this type of near-infrared LED device, near-infrared fluorescent materials are mixed with silicone resin and then coated onto the LED chip. The LED chip acts as the excitation source, exciting the near-infrared fluorescent material to achieve emission in the near-infrared region.

[0003] Fluorescent materials, including near-infrared fluorescent materials, are most commonly synthesized using high-temperature solid-state reactions. This involves subjecting a uniformly mixed powdered raw material to high-temperature heat treatment under a specific atmosphere. Near-infrared fluorescent materials consist of a matrix and luminescent centers. For example, patent document 1 (Shao Qiyue, Xu Xiaoxue, Yao Leqi, Dong Yan, Jiang Jianqing, A phosphate-based phosphor material and its preparation method and application, CN110862821B) discloses a material with the chemical formula... Phosphate-based near-infrared fluorescent materials, wherein A is at least one of Li, Na, and K, and B is at least one of Al, Ga, In, and Sc, with 0.01 ≤ x ≤ 0.1. ABP₂O₇ is the so-called matrix, specifically LiAlP₂O₇, NaInP₂O₇, or KScP₂O₇, etc., are examples of matrices, while Cr... 3+ It is the light-emitting center.

[0004] In the high-temperature solid-state synthesis of near-infrared fluorescent materials, the atmosphere must be considered. Atmospheres are generally classified as oxidizing or reducing atmospheres. The most common oxidizing atmosphere is air; reducing atmospheres include ammonia and nitrogen / hydrogen mixtures. For Cr... 3+For near-infrared fluorescent materials with luminescent centers, the following factors are typically considered when selecting the sintering atmosphere during high-temperature solid-state sintering: If the elements in the matrix material do not exhibit significant valence changes (e.g., Al is typically +3, Ca is typically +2, and K is typically +1), then either a reducing or oxidizing atmosphere can be chosen for sintering. This is because, regardless of whether a reducing or oxidizing atmosphere is used, the valence of the elements in the matrix does not change significantly during the sintering process of the near-infrared fluorescent material. Unchanged valence means unchanged optical properties (band gap) of the matrix, making luminescence (from the doped luminescent centers) possible. (Non-patent literature 1 (Zhenwei Jia, Chenxu Yuan, Yongfu Liu, Xiao-Jun Wang, Peng Sun, Lei Wang, Haochuan Jiang, Jun Jiang, Strategies to approach high performance in Cr...) 3+ (The paper "-doped phosphors for high-power NIR-LED lightsources, Light: Science & Applications, 2020, 9: 86" suggests that sintering samples in a reducing atmosphere can enhance the luminescence intensity of near-infrared fluorescent materials, provided that the valence of the elements in the matrix is ​​stable and there is no significant change in valence.)

[0005] Niobium (Nb) is located in group VB of the periodic table, and its common oxidation states are 2, 3, 4, and 5. The ion containing the highest oxidation state is Nb. 5+ If the compound is treated with a reducing atmosphere, Nb 5+ The oxidation state can easily change, becoming Nb. 4+ 、Nb 3+ 、Nb 2+ Even Nb, Nb in the matrix 5+ Changes in the valence of Nb will alter the optical band gap of the matrix, resulting in sintered fluorescent powders that are typically gray or grayish-black in color. These materials exhibit no or extremely weak luminescence under photoexcitation, essentially lacking the potential to function as fluorescent materials. Therefore, for Nb-containing... 5+ Near-infrared fluorescent materials are typically sintered in an air atmosphere. For example, Non-Patent Literature 2 (Xin Ding, Yu Min, Chang Wang, Qiang Zhang, Chromium doped broad-band near-infrared emission Mg4Ta2O9:Cr) 3+phosphor excitedby blue light for NIR-LEDs, Infrared Physics&Technology, 2023, 131, 104697) and chemical engineering 3 (Qingyang Ding, Jincheng Wu, Dechao Yu, Xinxin Han, Yayun Zhou,TiantianShen,Yunfeng Ma,Songlin Zhuang,Dawei Zhang,Broadband short-wave infraredMg4Nb2O9:Cr 3+ Li + phosphor for nondestructive safety detection and biomedical imaging,J. Mater. Chem. C, 2024, 12, 2184-2193) and 4(Kuangnan Lyu,Gaochao Liu,Maxim S. Molokeev,Zhiguo Xia,Double-Site Occupation TriggeredBroadband and Tunable NIR-I and NIR-II Luminescence in AlNbO4:Cr 3+Phosphors, Adv. Physics Res., 2023, 2, 2200056) and Non-Patent Literature 5 (Zixin Pan, Sisi Liang, Zihao Wang, Wendong Nie, Chenyang Zhan, Le Liu, Jinhao Chang, Fulin Lin, Haomiao Zhu, Broadband NIR phosphor with high external quantum yield and application of smoke penetration imaging, Journal of Luminescence, 2025, 283:121275) and Non-Patent Literature 6 (Peipei Niu, Li Li, Haoliang Yang, Yongjie Wang, Xianju Zhou, Zhongmin Cao, ShaJiang, Guangxin Xie, Guotao Xiang, Yongbin Hua, Highly Efficient Broadband NIRPhosphor Ca3ZrNbGa3O) 12 :Cr 3+ Yb 3+ (in pc-LED Applications, Carbon Neutralization, 2025, 4:e70032) and non-patent literature 7 (Lulu Lou, Shuang Zhao, Shuwen Yuan, Daoyun Zhu, Fugen Wu, Zhongfei Mu, Efficient broadband near-infrared emission induced by Nb 5+ substitution for Ta 5+ in GaTa 1-y Nb y O4:Cr 3+ The Nb-containing phosphorus (Inorganic Chemistry Frontiers, 2022, 9:3522-3531) and other publications disclose Nb-containing phosphorus. 5+ When using solid-state sintering methods, near-infrared fluorescent materials based on the matrix are all produced in an oxidizing atmosphere (air atmosphere) to ensure the Nb content. 5+ The oxidation state of Cr was stabilized, ultimately resulting in a high-performance compound with Cr... 3+ Niobium-based near-infrared fluorescent materials with luminescent centers.

[0006] In addition, existing Cr 3+ In near-infrared fluorescent materials with a (single) luminescent center, the half-width at half maximum (WHM) of the emission spectrum is usually difficult to reach 350 nm or higher. However, the larger the WHM of the emission spectrum of a near-infrared fluorescent material, the wider the detection range and the higher the detection accuracy of the encapsulated near-infrared LED device.

[0007] In summary, the existing technology lacks a method using Cr 3+ As a near-infrared luminescent center, it can produce Nb-containing compounds with superior luminescence properties under a reducing atmosphere. 5+ The compound is a near-infrared fluorescent material with a matrix structure and an emission spectrum with a full width at half maximum (FWHM) of over 350 nm. Regarding Ba6Ga under blue light excitation... 1-x Cr x Nb9O 30 The efficient and ultra-wide spectrum near-infrared luminescence behavior (0 < x ≤ 0.1) is disclosed for the first time in this invention. Summary of the Invention

[0008] The purpose of this invention is to solve the aforementioned problems in the prior art and provide a niobium-based near-infrared fluorescent material with an ultra-broad spectrum. Under blue light excitation at 455 nm, the main peak of the emission spectrum of this ultra-broad spectrum niobium-based near-infrared fluorescent material is located at 940–970 nm, the full width at half maximum (FWHM) of the emission spectrum is 350–380 nm, and the internal quantum efficiency ranges from 50% to 75%.

[0009] Therefore, the first objective of this invention is to provide a niobium-based near-infrared fluorescent material with an ultra-wide spectrum.

[0010] A niobium-based near-infrared fluorescent material with an ultra-broad spectrum can be represented by the following chemical formula:

[0011]

[0012] Where 0 < x ≤ 0.1.

[0013] Preferably, x can be 0.04.

[0014] A second objective of this invention is to provide a method for preparing a niobium-based near-infrared fluorescent material with an ultra-broad spectrum. The preparation method comprises the following steps: mixing precursors of Ba, Ga, Cr, and Nb, and carrying out a high-temperature solid-state reaction under a reducing atmosphere to obtain the aforementioned niobium-based near-infrared fluorescent material with an ultra-broad spectrum.

[0015] Preferably, the precursor of Ba is selected from BaCO3, the precursor of Ga is selected from Ga2O3, the precursor of Cr is selected from Cr2O3, and the precursor of Nb is selected from Nb2O5.

[0016] Preferably, the molar ratio of Ba, Ga, Cr and Nb in the precursors of Ba, Ga, Cr and Nb is 6:(1-x):x:9, where 0 < x ≤ 0.1.

[0017] Preferably, the purity of the precursors of Ba, Ga, Cr and Nb is not less than 99.5%.

[0018] Preferably, the temperature of the high-temperature solid-phase reaction is 1300-1400℃, the reducing atmosphere is a nitrogen / hydrogen mixture with a volume ratio of 75:25, and the reaction time is 3-5 hours.

[0019] Another object of the present invention is to provide a near-infrared LED device. The near-infrared LED device comprises a niobium-based near-infrared fluorescent material (chemical formula Ba6Ga) with an ultra-broad spectrum. 1-x Cr x Nb9O 30 (where 0 < x ≤ 0.1) and a blue LED chip capable of producing 425–480 nm light.

[0020] Compared with the prior art, the beneficial effects achieved by the technical solution of this invention are:

[0021] This invention provides a niobium-based near-infrared fluorescent material with an ultra-broad spectrum that can be obtained by sintering under a reducing atmosphere, such as Ba6Ga 1-x Cr x Nb9O 30 The chemical formula represents the near-infrared fluorescent material, where 0 < x ≤ 0.1. This ultra-broad-spectrum niobium-based near-infrared fluorescent material, under 455 nm blue light excitation, exhibits a main emission peak at 940–970 nm, a full width at half maximum (FWHM) of 350–380 nm, and an internal quantum efficiency ranging from 50% to 75%, thus enabling its application in the packaging of near-infrared LED devices. Attached Figure Description

[0022] Figure 1 The emission spectrum of the material obtained in Comparative Example 1 under blue light excitation at a wavelength of 455 nm is shown.

[0023] Figure 2 The image shows the X-ray diffraction pattern of the material obtained in Example 1.

[0024] Figure 3 This is a crystal structure diagram of the material obtained in Example 1.

[0025] Figure 4 The image shows the ESR of the material obtained in Example 1.

[0026] Figure 5 The emission spectrum of the material obtained in Example 1 under blue light excitation at a wavelength of 455 nm is shown.

[0027] Figure 6 The image shows the reflection absorption spectrum of the material obtained in Example 1. Detailed Implementation

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention.

[0029] To facilitate understanding of the present invention, embodiments are provided below. Those skilled in the art should understand that these embodiments are merely illustrative and should not be considered as specific limitations of the invention. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0030] This invention provides a niobium-based near-infrared fluorescent material with an ultra-broad spectrum, the chemical formula of which can be represented as follows:

[0031] Ba6Ga 1-x Cr x Nb9O 30

[0032] Where 0 < x ≤ 0.1.

[0033] In Embodiment 1 of the present invention, x is preferably 0.005; in Embodiment 2 of the present invention, x is preferably 0.01; in Embodiment 3 of the present invention, x is preferably 0.02; in Embodiment 4 of the present invention, x is preferably 0.03; in Embodiment 5 of the present invention, x is preferably 0.04; in Embodiment 6 of the present invention, x is preferably 0.05; in Embodiment 7 of the present invention, x is preferably 0.06; in Embodiment 8 of the present invention, x is preferably 0.07; in Embodiment 9 of the present invention, x is preferably 0.08; in Embodiment 10 of the present invention, x is preferably 0.09; and in Embodiment 11 of the present invention, x is preferably 0.1.

[0034] The present invention also provides a method for preparing a niobium-based near-infrared fluorescent material with an ultra-wide spectrum, the steps of which are as follows: Ba precursor, Ga precursor, Cr precursor and Nb precursor are mixed and subjected to high-temperature solid-phase reaction in a nitrogen / hydrogen mixed (reducing) atmosphere with a volume ratio of 75:25 to obtain a niobium-based near-infrared fluorescent material with an ultra-wide spectrum.

[0035] In the above steps, the molar ratio of Ba, Ga, Cr and Nb in the precursors of Ba, Ga, Cr and Nb is 6:(1-x):x:9, where 0<x≤0.1.

[0036] In the above steps, the precursor of Ba is selected from BaCO3, the precursor of Ga is selected from Ga2O3, the precursor of Cr is selected from Cr2O3, and the precursor of Nb is selected from Nb2O5.

[0037] The purity of the precursors of Ba, Ga, Cr and Nb is not less than 99.5%. The higher the purity, the fewer impurities are obtained in the phosphor.

[0038] In the above steps, the temperature of the high-temperature solid phase is preferably 1300-1400°C, and the atmosphere is a nitrogen / hydrogen mixture (reducing atmosphere) with a volume ratio of 75:25; in some embodiments provided by the present invention, the temperature of the high-temperature solid phase is preferably 1350°C.

[0039] In the above steps, the time for the high-temperature solid phase is preferably 3 to 5 hours, more preferably 3.5 to 4.5 hours; in some embodiments provided by the present invention, the time for the high-temperature solid phase is preferably 4 hours.

[0040] The above-mentioned high-temperature solid-state reaction is preferably carried out in a high-temperature furnace; after the reaction is carried out, the furnace is cooled to room temperature to obtain a niobium-based near-infrared fluorescent material with an ultra-wide spectrum.

[0041] The present invention employs a high-temperature solid-state reaction under a reducing atmosphere to successfully prepare a niobium-based near-infrared fluorescent material with an ultra-wide spectrum.

[0042] The present invention also provides a near-infrared LED device. This near-infrared LED device contains at least one chemical formula that can be represented as Ba6Ga. 1-x Cr x Nb9O 30 Niobium-based near-infrared fluorescent materials (where 0 < x ≤ 0.1) and blue LED chips with emission peak wavelengths in the range of 425–480 nm.

[0043] The specific manufacturing steps include: mixing a niobium-based near-infrared fluorescent material with an ultra-wide spectrum with epoxy resin, coating it onto the surface of a blue LED chip with an emission peak wavelength of 425–480 nm, and then curing it at 150°C for 2 hours to obtain a near-infrared LED device.

[0044] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, provides a niobium-based near-infrared fluorescent material with an ultra-broad spectrum and its preparation method. All reagents used in the following comparative examples and embodiments are commercially available.

[0045] Comparative Example 1

[0046] The raw materials were 0.06 mol BaCO3, 0.0048 mol Ga2O3, 0.0002 mol Cr2O3, and 0.045 mol Nb2O5. After grinding and mixing the raw materials, the mixture was placed in a crucible and sintered at 1350°C for 4 hours in a high-temperature furnace under air atmosphere. The mixture was then cooled to room temperature with the furnace to obtain a product with the theoretical chemical composition Ba6Ga 0.96 Cr 0.04 Nb9O 30 Materials.

[0047] The luminescence properties of the material corresponding to Comparative Example 1 were analyzed using a fluorescence spectrometer. Under 455 nm excitation, its emission spectrum is as follows: Figure 1 As shown, its emission spectrum has a main peak at 942 nm and a full width at half maximum (FWHM) of approximately 315 nm. Figure 1 As can be seen, the luminescence intensity of the sample obtained in Comparative Example 1 is extremely low. Generally speaking, Nb-containing... 5+ Materials containing Nb 5+ Sintering of the matrix (in order to avoid Nb) 5+ To prevent the change in oxidation state of Nb, an oxidizing atmosphere (air) is usually chosen to avoid it. 5+ Reduced to Nb 4 + 、Nb 3+ 、Nb 2+ Even Nb. Considering general understanding, based on the material corresponding to Comparative Example 1, despite using a suitable sintering temperature and atmosphere, the material's luminescence performance was poor. Therefore, it can be concluded that the material corresponding to Comparative Example 1 is not suitable as a near-infrared fluorescent material; furthermore, it would be unthinkable to change the sintering atmosphere, transforming it from an oxidizing atmosphere to a reducing atmosphere. This is because it is generally believed that Nb... 5+ It will be restored to Nb 4+ 、Nb 3+ 、Nb 2+ Even Nb, Nb in the matrix 5+ Changes in the oxidation state of the matrix will cause changes in the optical band gap, which means that the color of the sintered fluorescent material powder is usually gray or grayish-black. The material does not emit light at all or emits very little light when excited by light, and basically has no possibility of being used as a fluorescent material.

[0048] The quantum efficiency of the sample obtained in Comparative Example 1 was measured using a quantum efficiency tester, and it was found that its quantum efficiency was only 1.2%. Obviously, the sample obtained in Comparative Example 1 is not worth packaging into a near-infrared LED device.

[0049] That is, the data given in Comparative Example 1 shows that, based on the data containing Nb 5+ Materials containing Nb 5+Based on the general understanding of the matrix, under suitable temperature and a suitable (oxidizing) atmosphere, the synthesized sample exhibits extremely poor luminescence properties, which basically indicates that the matrix corresponding to Comparative Example 1 is Cr-doped. 3+ This is not suitable for use as a near-infrared fluorescent material, and those in the art have no intention of changing the oxidizing atmosphere to a reducing atmosphere for sintering the sample. This is because it is generally believed that for Nb-containing materials... 5+ Materials containing Nb 5+ The matrix is ​​not suitable for sintering in a reducing atmosphere; after sintering in a reducing atmosphere, it contains Nb. 5+ Near-infrared fluorescent materials often do not emit light.

[0050] Example 1

[0051] The raw materials were 0.06 mol BaCO3, 0.004975 mol Ga2O3, 0.000025 mol Cr2O3, and 0.045 mol Nb2O5. After grinding and mixing the raw materials, the mixture was placed in a crucible and sintered at 1350℃ for 4 hours in a high-temperature furnace under a nitrogen / hydrogen mixture (reducing) atmosphere with a volume ratio of 75:25. The mixture was then cooled to room temperature with the furnace to obtain a product with the theoretical chemical composition Ba6Ga 0.995 Cr 0.005 Nb9O 30 Materials.

[0052] The structure of the material obtained in Example 1 was analyzed by X-ray diffraction using an X-ray diffractometer, and its diffraction pattern is shown below. Figure 2 As shown. By comparing with a powder structure database, its diffraction data is similar to that of Ba6GaNb9O. 30 The diffraction patterns of the two materials are similar, indicating that the material obtained in Example 1 is a Cr-doped niobium-based fluorescent material. Single-crystal diffraction analysis, combined with data from powder structure refinement, shows that Cr... 3+ Indeed occupying Ga 3+ The crystallographic position. Figure 3 The crystal structure diagram of this material is given. Electron paramagnetic resonance (ESR) measurements were performed on this material, and the resulting spectra are shown below. Figure 4 As shown, Cr can be clearly observed. 3+ The ESR signal occupying the six-coordinate octahedron further illustrates that Cr 3+ Indeed occupied Ga 3+ The crystallographic lattice sites. The luminescence properties of the material corresponding to Example 1 were analyzed using fluorescence spectroscopy. Under 455 nm excitation, its emission spectrum is as follows: Figure 5 As shown. Contrary to common knowledge in the art, after employing a reducing atmosphere, the Nb corresponding to Example 1... 5+The material exhibits high emission intensity, producing near-infrared emission with a main peak wavelength of approximately 940 nm and a full width at half maximum (FWHM) of approximately 350 nm. The quantum efficiency of the sample obtained in Example 1 was measured using a quantum efficiency meter, revealing a quantum efficiency of 52.5%, as shown in Table 1. The sample obtained in this example is predominantly light pink. Figure 6 The reflection absorption spectrum of the sample was obtained using a reflection absorption spectrometer, and it can be seen that the obtained sample has a strong absorption of blue light.

[0053] That is, the data given in Example 1 shows that the near-infrared luminescence properties of the material corresponding to Example 1 have counterintuitive characteristics, that is, for the Nb-containing material... 5+ Materials containing Nb 5+ Under suitable temperature and reducing atmosphere, the luminescence properties of the synthesized sample were enhanced, corresponding to the matrix doped with Cr. 3+ It is very suitable for use as a near-infrared fluorescent material.

[0054] Example 2

[0055] The raw materials were 0.06 mol BaCO3, 0.00495 mol Ga2O3, 0.00005 mol Cr2O3, and 0.045 mol Nb2O5. After grinding and mixing the raw materials, the mixture was placed in a crucible and sintered at 1350℃ for 4 hours in a high-temperature furnace under a nitrogen / hydrogen mixture (reducing) atmosphere with a volume ratio of 75:25. The mixture was then cooled to room temperature with the furnace to obtain a product with the theoretical chemical composition Ba6Ga 0.99 Cr 0.01 Nb9O 30 Materials.

[0056] The luminescence properties of the material in Example 2 were analyzed using a fluorescence spectrometer. Under 455 nm excitation, the intensity of its emission spectrum was high. The quantum efficiency of the obtained sample was measured using a quantum efficiency tester, and it was found that the quantum efficiency was high. The specific values ​​of the main peak data of the emission spectrum, luminescence intensity and quantum efficiency of the material can be seen in Table 1.

[0057] That is, the data given in Example 2 shows that the near-infrared luminescence properties of the material corresponding to Example 2 have counterintuitive characteristics, that is, for the Nb-containing material... 5+ Materials containing Nb 5+ Under suitable temperature and reducing atmosphere, the luminescence properties of the synthesized sample were enhanced, corresponding to the matrix doped with Cr. 3+ It is very suitable for use as a near-infrared fluorescent material.

[0058] Example 3

[0059] The raw materials were 0.06 mol BaCO3, 0.0049 mol Ga2O3, 0.0001 mol Cr2O3, and 0.045 mol Nb2O5. After grinding and mixing the raw materials, the mixture was placed in a crucible and sintered at 1350 °C for 4 hours in a high-temperature furnace under a nitrogen / hydrogen mixture (reducing) atmosphere with a volume ratio of 75:25. The mixture was then cooled to room temperature with the furnace to obtain a product with the theoretical chemical composition Ba6Ga 0.98 Cr 0.02 Nb9O 30 Materials.

[0060] The luminescence properties of the material in Example 3 were analyzed using a fluorescence spectrometer. Under 455 nm excitation, the intensity of its emission spectrum was high. The quantum efficiency of the obtained sample was measured using a quantum efficiency tester, and it was found that the quantum efficiency was high. The specific values ​​of the main peak data of the emission spectrum, luminescence intensity and quantum efficiency of the material can be seen in Table 1.

[0061] That is, the data given in Example 3 shows that the near-infrared luminescence properties of the material corresponding to Example 3 have counterintuitive characteristics, that is, for the Nb-containing material... 5+ Materials containing Nb 5+ Under suitable temperature and reducing atmosphere, the luminescence properties of the synthesized sample were enhanced, corresponding to the matrix doped with Cr. 3+ It is very suitable for use as a near-infrared fluorescent material.

[0062] Example 4

[0063] The raw materials were 0.06 mol BaCO3, 0.00485 mol Ga2O3, 0.00015 mol Cr2O3, and 0.045 mol Nb2O5. After grinding and mixing the raw materials, the mixture was placed in a crucible and sintered at 1350 °C for 4 hours in a high-temperature furnace under a nitrogen / hydrogen mixture (reducing) atmosphere with a volume ratio of 75:25. The mixture was then cooled to room temperature with the furnace to obtain a product with the theoretical chemical composition Ba6Ga 0.97 Cr 0.03 Nb9O 30 Materials.

[0064] The luminescence properties of the material in Example 4 were analyzed using a fluorescence spectrometer. Under 455 nm excitation, the intensity of its emission spectrum was high. The quantum efficiency of the obtained sample was measured using a quantum efficiency tester, and it was found that the quantum efficiency was high. The specific values ​​of the main peak data of the emission spectrum, luminescence intensity and quantum efficiency of the material can be seen in Table 1.

[0065] That is, the data given in Example 4 shows that the near-infrared luminescence properties of the material corresponding to Example 4 have counterintuitive characteristics, that is, for the Nb-containing material... 5+ Materials containing Nb 5+Under suitable temperature and reducing atmosphere, the luminescence properties of the synthesized sample were enhanced, corresponding to the matrix doped with Cr. 3+ It is very suitable for use as a near-infrared fluorescent material.

[0066] Example 5

[0067] The raw materials were 0.06 mol BaCO3, 0.0048 mol Ga2O3, 0.0002 mol Cr2O3, and 0.045 mol Nb2O5. After grinding and mixing the raw materials, the mixture was placed in a crucible and sintered at 1350 °C for 4 hours in a high-temperature furnace under a nitrogen / hydrogen mixture (reducing) atmosphere with a volume ratio of 75:25. The mixture was then cooled to room temperature with the furnace to obtain a product with the theoretical chemical composition Ba6Ga 0.96 Cr 0.04 Nb9O 30 Materials.

[0068] The luminescence properties of the material in Example 5 were analyzed using a fluorescence spectrometer. Under 455 nm excitation, the intensity of its emission spectrum was high. The quantum efficiency of the obtained sample was measured using a quantum efficiency tester, and it was found that the quantum efficiency was high. The specific values ​​of the main peak data of the emission spectrum, luminescence intensity and quantum efficiency of the material can be seen in Table 1.

[0069] That is, the data given in Example 5 shows that the near-infrared luminescence properties of the material corresponding to Example 5 have counterintuitive characteristics, that is, for the Nb-containing material... 5+ Materials containing Nb 5+ Under suitable temperature and reducing atmosphere, the luminescence properties of the synthesized sample were enhanced, corresponding to the matrix doped with Cr. 3+ It is very suitable for use as a near-infrared fluorescent material.

[0070] Example 6

[0071] The raw materials were 0.06 mol BaCO3, 0.00475 mol Ga2O3, 0.00025 mol Cr2O3, and 0.045 mol Nb2O5. After grinding and mixing the raw materials, the mixture was placed in a crucible and sintered at 1350 °C for 4 hours in a high-temperature furnace under a nitrogen / hydrogen mixture (reducing) atmosphere with a volume ratio of 75:25. The mixture was then cooled to room temperature with the furnace to obtain a product with the theoretical chemical composition Ba6Ga 0.95 Cr 0.05 Nb9O 30 Materials.

[0072] The luminescence properties of the material corresponding to Example 6 were analyzed using a fluorescence spectrometer. Under 455 nm excitation, the intensity of its emission spectrum was high. The quantum efficiency of the obtained sample was measured using a quantum efficiency tester, and it was found that the quantum efficiency was high. The specific values ​​of the main peak data of the emission spectrum, luminescence intensity and quantum efficiency of the material can be seen in Table 1.

[0073] That is, the data given in Example 6 shows that the near-infrared luminescence properties of the material corresponding to Example 6 have counterintuitive characteristics, that is, for the Nb-containing material... 5+ Materials containing Nb 5+ Under suitable temperature and reducing atmosphere, the luminescence properties of the synthesized sample were enhanced, corresponding to the matrix doped with Cr. 3+ It is very suitable for use as a near-infrared fluorescent material.

[0074] Example 7

[0075] The raw materials were 0.06 mol BaCO3, 0.0047 mol Ga2O3, 0.0003 mol Cr2O3, and 0.045 mol Nb2O5. After grinding and mixing the raw materials, the mixture was placed in a crucible and sintered at 1350°C for 4 hours in a high-temperature furnace under a nitrogen / hydrogen mixture (reducing) atmosphere with a volume ratio of 75:25. The mixture was then cooled to room temperature with the furnace to obtain a product with the theoretical chemical composition Ba6Ga 0.94 Cr 0.06 Nb9O 30 Materials.

[0076] The luminescence properties of the material in Example 7 were analyzed using a fluorescence spectrometer. Under 455 nm excitation, the intensity of its emission spectrum was high. The quantum efficiency of the obtained sample was measured using a quantum efficiency tester, and it was found that the quantum efficiency was high. The specific values ​​of the main peak data of the emission spectrum, luminescence intensity and quantum efficiency of the material can be seen in Table 1.

[0077] That is, the data given in Example 7 shows that the near-infrared luminescence properties of the material corresponding to Example 7 have counterintuitive characteristics, that is, for the Nb-containing material... 5+ Materials containing Nb 5+ Under suitable temperature and reducing atmosphere, the luminescence properties of the synthesized sample were enhanced, corresponding to the matrix doped with Cr. 3+ It is very suitable for use as a near-infrared fluorescent material.

[0078] Example 8

[0079] The raw materials were 0.06 mol BaCO3, 0.00465 mol Ga2O3, 0.00035 mol Cr2O3, and 0.045 mol Nb2O5. After grinding and mixing the raw materials, the mixture was placed in a crucible and sintered at 1350 °C for 4 hours in a high-temperature furnace under a nitrogen / hydrogen mixture (reducing) atmosphere with a volume ratio of 75:25. The mixture was then cooled to room temperature with the furnace to obtain a product with the theoretical chemical composition Ba6Ga 0.93 Cr 0.07 Nb9O 30 Materials.

[0080] The luminescence properties of the material corresponding to Example 8 were analyzed using a fluorescence spectrometer. Under 455 nm excitation, the intensity of its emission spectrum was high. The quantum efficiency of the obtained sample was measured using a quantum efficiency tester, and it was found that the quantum efficiency was high. The specific values ​​of the main peak data of the emission spectrum, luminescence intensity and quantum efficiency of the material can be seen in Table 1.

[0081] That is, the data given in Example 8 shows that the near-infrared luminescence properties of the material corresponding to Example 8 have counterintuitive characteristics, that is, for the Nb-containing material... 5+ Materials containing Nb 5+ Under suitable temperature and reducing atmosphere, the luminescence properties of the synthesized sample were enhanced, corresponding to the matrix doped with Cr. 3+ It is very suitable for use as a near-infrared fluorescent material.

[0082] Example 9

[0083] The raw materials were 0.06 mol BaCO3, 0.0046 mol Ga2O3, 0.0004 mol Cr2O3, and 0.045 mol Nb2O5. After grinding and mixing the raw materials, the mixture was placed in a crucible and sintered at 1350 °C for 4 hours in a high-temperature furnace under a nitrogen / hydrogen mixture (reducing) atmosphere with a volume ratio of 75:25. The mixture was then cooled to room temperature with the furnace to obtain a product with the theoretical chemical composition Ba6Ga 0.92 Cr 0.08 Nb9O 30 Materials.

[0084] The luminescence properties of the material corresponding to Example 9 were analyzed using a fluorescence spectrometer. Under 455 nm excitation, the intensity of its emission spectrum was high. The quantum efficiency of the obtained sample was measured using a quantum efficiency tester, and it was found that the quantum efficiency was high. The specific values ​​of the main peak data of the emission spectrum, luminescence intensity and quantum efficiency of the material can be seen in Table 1.

[0085] That is, the data given in Example 9 shows that the near-infrared luminescence properties of the material corresponding to Example 9 have counterintuitive characteristics, that is, for the Nb-containing material... 5+ Materials containing Nb 5+Under suitable temperature and reducing atmosphere, the luminescence properties of the synthesized sample were enhanced, corresponding to the matrix doped with Cr. 3+ It is very suitable for use as a near-infrared fluorescent material.

[0086] Example 10

[0087] The raw materials were 0.06 mol BaCO3, 0.00455 mol Ga2O3, 0.00045 mol Cr2O3, and 0.045 mol Nb2O5. After grinding and mixing the raw materials, the mixture was placed in a crucible and sintered at 1350℃ for 4 hours in a high-temperature furnace under a nitrogen / hydrogen mixture (reducing) atmosphere with a volume ratio of 75:25. The mixture was then cooled to room temperature with the furnace to obtain a product with the theoretical chemical composition Ba6Ga 0.91 Cr 0.09 Nb9O 30 Materials.

[0088] The luminescence properties of the material corresponding to Example 10 were analyzed using a fluorescence spectrometer. Under 455 nm excitation, the intensity of its emission spectrum was high. The quantum efficiency of the obtained sample was measured using a quantum efficiency tester, and it was found that the quantum efficiency was high. The specific values ​​of the main peak data of the emission spectrum, luminescence intensity and quantum efficiency of the material can be seen in Table 1.

[0089] That is, the data given in Example 10 shows that the near-infrared luminescence properties of the material corresponding to Example 10 have counterintuitive characteristics, that is, for the Nb-containing material... 5+ Materials containing Nb 5+ Under suitable temperature and reducing atmosphere, the luminescence properties of the synthesized sample were enhanced, corresponding to the matrix doped with Cr. 3+ It is very suitable for use as a near-infrared fluorescent material.

[0090] Example 11

[0091] The raw materials were 0.06 mol BaCO3, 0.0045 mol Ga2O3, 0.0005 mol Cr2O3, and 0.045 mol Nb2O5. After grinding and mixing the raw materials, the mixture was placed in a crucible and sintered at 1350°C for 4 hours in a high-temperature furnace under a nitrogen / hydrogen mixture (reducing) atmosphere with a volume ratio of 75:25. The mixture was then cooled to room temperature with the furnace to obtain a product with the theoretical chemical composition Ba6Ga 0.9 Cr 0.1 Nb9O 30 Materials.

[0092] The luminescence properties of the material corresponding to Example 11 were analyzed using a fluorescence spectrometer. Under 455 nm excitation, the intensity of its emission spectrum was high. The quantum efficiency of the obtained sample was measured using a quantum efficiency tester, and it was found that the quantum efficiency was high. The specific values ​​of the main peak data of the emission spectrum, luminescence intensity and quantum efficiency of the material can be seen in Table 1.

[0093] That is, the data given in Example 11 shows that the near-infrared luminescence properties of the material corresponding to Example 11 have counterintuitive characteristics, that is, for the Nb-containing material... 5+ Materials containing Nb 5+ Under suitable temperature and reducing atmosphere, the luminescence properties of the synthesized sample were enhanced, corresponding to the matrix doped with Cr. 3+ It is very suitable for use as a near-infrared fluorescent material.

[0094] Table 1. Luminescent properties of the materials corresponding to the comparative examples and embodiments.

[0095]

[0096] Example 12

[0097] The Ba6Ga synthesized in Example 5 was selected. 0.96 Cr 0.04 Nb9O 30 Near-infrared fluorescent material is mixed with epoxy resin at a mass ratio of 1:3.5. The mixture is then coated onto a blue LED with the main emission peak located at 450 nm, encapsulated, and cured at 150°C for 2 hours to obtain a near-infrared LED device.

[0098] The above embodiments are merely illustrative of the implementation methods of the present invention and to explain the technical features of the present invention, and are not intended to limit the scope of protection of the present invention. Any changes or equivalent arrangements that can be easily made by those skilled in the art are within the scope of the present invention, and the scope of protection of the present invention should be determined by the claims.

Claims

1. A niobium-based near-infrared fluorescent material with an ultra-broad spectrum, characterized in that: The general chemical formula is Where 0 < x ≤ 0.1; under blue light excitation at 455 nm, the main peak of the emission spectrum of the niobium-based near-infrared fluorescent material with ultra-wide spectrum is located at 940–970 nm, the half-width at half-maximum is 350–380 nm, and the internal quantum efficiency is in the range of 50%–75%.

2. The niobium-based near-infrared fluorescent material with an ultra-broad spectrum as described in claim 1, characterized in that: The value of x is 0.

04.

3. A method for preparing a niobium-based near-infrared fluorescent material with an ultra-broad spectrum as described in any one of claims 1 to 2, characterized in that: The precursors of Ba, Ga, Cr and Nb were mixed and subjected to a high-temperature solid-state reaction under a reducing atmosphere to obtain the niobium-based near-infrared fluorescent material with an ultra-wide spectrum.

4. The method for preparing a niobium-based near-infrared fluorescent material with an ultra-wide spectrum as described in claim 3, characterized in that: The precursor of Ba is selected from BaCO3, the precursor of Ga is selected from Ga2O3, the precursor of Cr is selected from Cr2O3, and the precursor of Nb is selected from Nb2O5; the purity of the precursors of Ba, Ga, Cr and Nb is not less than 99.5%.

5. The method for preparing a niobium-based near-infrared fluorescent material with an ultra-wide spectrum as described in claim 3, characterized in that: The molar ratio of Ba, Ga, Cr, and Nb in the precursors of Ba, Ga, Cr, and Nb is 6:(1-x):x:9, where 0 < x ≤ 0.

1.

6. The method for preparing a niobium-based near-infrared fluorescent material with an ultra-wide spectrum as described in claim 3, characterized in that: The reducing atmosphere is a nitrogen / hydrogen mixture with a volume ratio of 75:

25.

7. The method for preparing a niobium-based near-infrared fluorescent material with an ultra-wide spectrum as described in claim 3, characterized in that: The high-temperature solid-phase reaction is carried out at a temperature of 1300–1400°C for 3–5 hours.

8. The application of a niobium-based near-infrared fluorescent material with an ultra-broad spectrum as described in any one of claims 1 to 2, or a niobium-based near-infrared fluorescent material with an ultra-broad spectrum obtained by the preparation method of any one of claims 3 to 7, characterized in that: Packaging for near-infrared LED devices.

9. A near-infrared LED device, characterized in that: This includes a niobium-based near-infrared fluorescent material with an ultra-broad spectrum as described in any one of claims 1 to 2, or a niobium-based near-infrared fluorescent material with an ultra-broad spectrum obtained by any one of claims 3 to 7.

10. A near-infrared LED device as described in claim 9, characterized in that: It also includes blue LED chips with emission peak wavelengths in the range of 425–480 nm.

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