Borate-based near-infrared luminescent material as well as preparation method and application thereof

Abstract

The invention discloses a borate-based near-infrared luminescent material as well as a preparation method and application thereof, and belongs to the technical field of near-infrared luminescent materials. The chemical general formula of the borate-based near-infrared luminescent material disclosed by the invention is Y1-xGa3 (BO3) 4: xEr < 3 + >, and x is more than or equal to 0.05 and less than or equal to 0.25. By regulating the doping proportion of the Er < 3 + > component, the light-emitting peak position and the light-emitting efficiency are finely regulated; a rare earth ion Er < 3 + > is doped in a Y1-xGa3 (BO3) 4: xEr < 3 + > compound to form a luminescent material with a new component, the excitation peak value of the luminescent material is 365 nm ultraviolet light and 980 nm near-infrared light, the emission wavelength is within the range of 1400-1700 nm, the luminescent material can be well matched with an ultraviolet light chip, and the technical problem that the existing fluorescent powder is difficult to realize near-infrared band luminescence is solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of near-infrared luminescent materials, and particularly relates to a borate-based near-infrared luminescent material and a preparation method and application thereof. BACKGROUND

[0002] Near-infrared light is electromagnetic waves between visible light and mid-infrared light, and has a wide range of applications in the fields of optical communication, non-destructive food analysis, plant growth, environmental monitoring, night vision and biomedical imaging due to its low energy, high penetration and non-destructive nature. Current light sources such as halogen lamps, incandescent lamps and near-infrared LEDs have problems such as large size, short service life and narrow spectral coverage, while near-infrared fluorescent powder conversion type light-emitting diodes are attracting attention due to their advantages such as tunable broadband emission spectrum, small size, high efficiency and long service life.

[0003] Near-infrared fluorescent powder is a key component of near-infrared fluorescent powder conversion type LED devices, and plays a key role in adjusting the spectrum, efficiency and service life of near-infrared fluorescent powder conversion type LED devices. Near-infrared fluorescent powder is usually composed of a matrix material and an activating ion, and borate matrix materials have become a research focus in the field of near-infrared fluorescent materials due to their good chemical stability and rich structural diversity. In addition, activating ions can be roughly divided into lanthanide ions and transition metal ions, and currently, many researches focus on near-infrared fluorescent powder doped with transition metal ions, while the research on near-infrared fluorescent powder doped with lanthanide ions has more rich tunability.

[0004] Among lanthanide ions, trivalent erbium ions have a rich energy level structure, which enables them to realize both up-conversion luminescence and down-conversion luminescence. For example, a La 7- x O6(BO3)(PO4)2:Er 3+ fluorescent powder disclosed in Chinese Patent Application No. CN110846035A can be excited by near-ultraviolet light to emit green light. A NaLuF4:Er 3+ / Ho 3+ / Tm 3+ fluorescent powder disclosed in Chinese Patent No. CN109337687B realizes high red / green ratio red up-conversion luminescence through high Er 3+ doping. The above patents confirm that erbium-doped fluorescent powder can realize visible light emission by reasonably controlling excitation conditions and matrix composition. However, the current researches mainly focus on the visible light application direction of erbium-doped fluorescent powder, and there is still a lack of near-infrared band luminescent performance. SUMMARY

[0005] The present application aims to provide a borate-based near-infrared luminescent material, a preparation method and application thereof, so as to solve the technical problem that the existing fluorescent powder is difficult to realize near-infrared band luminescence.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions: The present application discloses a borate-based near-infrared luminescent material, the chemical general formula of the borate-based near-infrared luminescent material is Y 1-x Ga3(BO3)4:xEr 3+ , wherein 0.05<=x<=0.25.

[0007] Further, the borate-based near-infrared luminescent material emits a peak range of 1400-1700 nm under excitation of 365 nm or 980 nm wavelength, and the emission center is located at 1528 nm, belonging to near-infrared 2 area emission.

[0008] The present application also discloses a preparation method of the above-mentioned borate-based near-infrared luminescent material, comprising the following steps: According to the mole ratio of each element in the chemical general formula, the raw materials are weighed and mixed and ground to obtain a mixed powder, the mixed powder is tabletted to obtain a bulk material, and the bulk material is sintered to obtain the borate-based near-infrared luminescent material.

[0009] Further, the raw materials are a Y element-containing precursor, a Ga element-containing precursor, a B element-containing precursor and an Er element-containing precursor.

[0010] Further, the Y element-containing precursor is any one of Y(NO3)3·6H2O, Y2(CO3)3 and Y2O3 or a mixture of two or more thereof in any proportion.

[0011] Further, the Ga element-containing precursor is Ga2O3. The B element-containing precursor is any one of H3BO3 and B2O3 or a mixture of the two in any proportion.

[0012] Further, the Er element-containing precursor is any one of Er(NO3)3·6H2O and Er2O3 or a mixture of the two in any proportion.

[0013] Further, the mixing and grinding time is 15-30 min.

[0014] Further, the sintering temperature is 950-1050 DEG C, and the sintering time is 4-8 h.

[0015] The present invention also discloses the application of the above-mentioned borate-based near-infrared luminescent material in near-infrared phosphor-converted LED devices.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a borate-based near-infrared luminescent material, according to Y 1-x Ga3(BO3)4:xEr 3+ Among them, material innovation can be carried out using the general chemical formula with 0.05 ≤ x ≤ 0.25, which can be achieved by regulating Er. 3+ By adjusting the doping ratio of components, the surrounding crystal field environment is altered, and the internal energy transfer process is modulated, thereby achieving precise control over the emission peak position and luminescence efficiency. For example, with the doping ratio of Er... 3+ As the concentration of Er increases, 3+ -Er 3+ The increased probability of its existence leads to local distortion of the surrounding crystal field, causing Er 3+ The degree of energy level splitting increases, which macroscopically manifests as a slight shift in the emission peak position. Furthermore, when Er... 3+ When the doping concentration is low, Er 3+ The energy transfer between them is relatively weak, resulting in high luminous efficiency. However, with increasing doping concentration, Er... 3+ Enhanced energy transfer between them leads to an increase in non-radiative transitions, thereby reducing the occurrence of radiative transitions and resulting in a decrease in luminescence efficiency; the rare earth ion Er 3+ Doping in Y 1-x Ga3(BO3)4: xEr 3+ The compound forms a new luminescent material with an excitation peak of 365 nm ultraviolet light and 980 nm near-infrared light, and an emission wavelength in the range of 1400-1700 nm. This material can be well matched with ultraviolet light chips, solving the technical problem that existing phosphors are difficult to achieve near-infrared light emission.

[0017] This invention also discloses a method for preparing the above-mentioned borate-based near-infrared luminescent material. The preparation process involves grinding and sintering, requires no special atmosphere, is simple, has a relatively low synthesis temperature, and uses abundant, inexpensive, and readily available raw materials, enabling industrial-scale production.

[0018] This invention also discloses the application of the above-mentioned borate-based near-infrared luminescent material in near-infrared phosphor-converting LED devices. The combination of this infrared luminescent material with an ultraviolet LED chip can be used to make near-infrared phosphor-converting LED devices, which have broad application prospects in fields such as biomedical imaging, anti-counterfeiting, and non-destructive testing. Attached Figure Description

[0019] Figure 1The XRD patterns of the borate-based near-infrared luminescent material prepared in Example 1 of this invention and the corresponding standard cards are shown. Figure 2 Y, as described in Embodiment 1 of the present invention 0.95 Ga3(BO3)4: 0.05Er 3+ Crystal structure characterization; Figure 3 Y, as described in Embodiment 1 of the present invention 0.95 Ga3(BO3)4: 0.05Er 3+ SEM images and elemental distribution maps of the phosphor; Figure 4 Y, as described in Embodiment 1 of the present invention 0.95 Ga3(BO3)4: 0.05Er 3+ Emission spectrum of phosphor under 365 nm excitation; Figure 5 Y, as described in Embodiment 1 of the present invention 0.95 Ga3(BO3)4: 0.05Er 3+ Emission spectrum of phosphor under 980 nm excitation; Figure 6 Y in Embodiment 2 of the present invention 0.92 Ga3(BO3)4: 0.08Er 3+ Emission spectrum of phosphor under 365 nm excitation; Figure 7 Y, as described in Embodiment 2 of the present invention 0.92 Ga3(BO3)4: 0.08Er 3+ Emission spectrum of phosphor under 980 nm excitation; Figure 8 Y, as described in Embodiment 3 of the present invention 0.88 Ga3(BO3)4: 0.12Er 3+ Emission spectrum of phosphor under 365 nm excitation; Figure 9 Y, as described in Embodiment 3 of the present invention 0.88 Ga3(BO3)4: 0.12Er 3+ Emission spectrum of phosphor under 980 nm excitation; Figure 10 Y, as described in Embodiment 4 of the present invention 0.85 Ga3(BO3)4: 0.15Er 3+ Emission spectrum of phosphor under 365 nm excitation; Figure 11 Y, as described in Embodiment 4 of the present invention 0.85 Ga3(BO3)4: 0.15Er 3+Emission spectrum of phosphor under 980 nm excitation; Figure 12 Y, as described in Embodiment 5 of the present invention 0.82 Ga3(BO3)4: 0.18Er 3+ Emission spectrum of phosphor under 365 nm excitation; Figure 13 Y, as described in Embodiment 5 of the present invention 0.82 Ga3(BO3)4: 0.18Er 3+ Emission spectrum of phosphor under 980 nm excitation; Figure 14 Y, as described in Embodiment 6 of the present invention 0.8 Ga3(BO3)4: 0.2Er 3+ Emission spectrum of phosphor under 365 nm excitation; Figure 15 Y, as described in Embodiment 6 of the present invention 0.8 Ga3(BO3)4: 0.2Er 3+ Emission spectrum of phosphor under 980 nm excitation; Figure 16 Y, as described in Embodiment 7 of the present invention 0.75 Ga3(BO3)4: 0.25Er 3+ Emission spectrum of phosphor under 365 nm excitation; Figure 17 Y in Embodiment 7 of the present invention 0.75 Ga3(BO3)4: 0.25Er 3+ Emission spectrum of phosphor under 980 nm excitation; Figure 18 Y in embodiments 1-7 of the present invention 1-x Ga3(BO3)4: xEr 3+ (0.05≤x≤0.25) XRD patterns of phosphor and standard cards of YGa3(BO3)4; Figure 19 Y in embodiments 1-7 of the present invention 1-x Ga3(BO3)4: xEr 3+ (0.05≤x≤0.25) The fluorescence intensity of the phosphor under 365nm excitation varies with Er 3+ Trend graph of doping content; Figure 20 Y in embodiments 1-7 of the present invention 1-x Ga3(BO3)4: xEr 3+ (0.05≤x≤0.25) The fluorescence intensity of the phosphor under 980nm excitation varies with Er 3+Trend graph of doping content. Detailed Implementation

[0020] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0021] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0022] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0023] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0024] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0025] This invention provides a borate-based near-infrared luminescent material, wherein the general chemical formula of the fluorescent material is Y. 1-x Ga3(BO3)4: xEr 3+ Where 0.05≤x≤0.25.

[0026] This invention also discloses a method for preparing the above-mentioned borate-based near-infrared luminescent material, comprising the following steps: S1: Based on the general chemical formula Y 1-x Ga3(BO3)4: xEr 3+The raw materials are weighed according to the molar ratio of each element in the raw materials Y: Ga: B: Er=1-x: 3: 4: x, wherein the raw materials include precursors containing Y, Ga, B and Er respectively; the weighed raw materials are placed in a mortar and ground for a period of time to obtain a uniformly mixed powder; a certain amount of the ground powder is weighed and placed into a mold, and then placed into a powder tableting machine for tableting. S2: Transfer the compressed block to a crucible, then place it in a muffle furnace and heat it to 950-1050 ℃ for 4-8 h at a heating rate of 5-10 ℃ / min. Then slowly cool it to room temperature to obtain the borate-based near-infrared fluorescent material.

[0027] Preferably, the precursor containing Y element is any one or a mixture of two or more of Y(NO3)3·6H2O, Y2(CO3)3 and Y2O3 in any proportion.

[0028] Preferably, the precursor containing Ga is Ga2O3.

[0029] Preferably, the precursor containing element B is any one of H3BO3 and B2O3 or a mixture of both in any proportion.

[0030] Preferably, the precursor containing Er element is any one of Er(NO3)3·6H2O and Er2O3 or a mixture of both in any proportion.

[0031] Preferably, the grinding time in step S1 is 15-30 min.

[0032] The borate-based near-infrared luminescent material disclosed in this invention has an emission peak range of 1400-1700 nm under excitation at wavelengths of 365 nm or 980 nm, with the emission center located at 1528 nm.

[0033] The present invention also discloses the application of the above-mentioned borate-based near-infrared fluorescent material in near-infrared phosphor conversion LED devices.

[0034] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0035] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0036] Example 1 A method for preparing a borate-based near-infrared luminescent material includes the following steps: According to the elemental stoichiometry of Y:Ga:B:Er, weigh out the raw materials as follows: 0.4043 g Y(NO3)3·6H2O, 0.2916 g Ga2O3, 0.2748 g H3BO3, and 0.0256 g Er(NO3)3·6H2O. Grind the above raw materials in a mortar for 15 minutes to make them uniformly mixed. Put the mixed powder into a mold and then put it into a powder tablet press for tableting to obtain the bulk material. The bulk material was transferred to a crucible, which was then placed in a muffle furnace. The crucible was heated to 1000 °C at a heating rate of 10 °C / min under air atmosphere and sintered for 4 h. Afterward, it was slowly cooled to room temperature to obtain Y. 0.95 Ga3(BO3)4: 0.05Er 3+ Near-infrared phosphor (borate-based near-infrared luminescent material).

[0037] Figure 1 The XRD patterns of the borate-based near-infrared luminescent material prepared in Example 1 of this invention and the corresponding standard cards are shown below. Figure 1 It can be known that Y 3+ (r=1.011Å) and Er 3+ (r=1.004Å) have the same valence state and similar ionic radii, Er 3+ They will tend to occupy Y 3+ The position of the diffraction peaks of the obtained sample is basically consistent with that of the YGa3(BO3)4 standard card (PDF#04-002-9354), indicating that the YGa3(BO3)4 phase has been successfully synthesized. Figure 2 Y, as described in Embodiment 1 of the present invention 0.95 Ga3(BO3) 40.05Er 3+ Crystal structure characterization, from Figure 2 It can be known that Y 3+ and Ga 3+ Both coordinate with six oxygen atoms to form [YO6] octahedrons and [GaO6] octahedrons, respectively. 3+The [BO3] octahedron coordinates with three oxygen atoms to form a [BO3] planar triangle. The [YO6] octahedron exhibits a slight triangular prism distortion, while the [GaO6] octahedron approximates an ideal octahedron. Adjacent [YO6] octahedrons are connected to the [BO3] planar triangle by sharing vertex oxygen atoms, while adjacent [GaO6] octahedrons are connected by sharing edges, collectively forming a stable structure. Figure 3 Y, as described in Embodiment 1 of the present invention 0.95 Ga3(BO3)4: 0.05Er 3+ SEM images and elemental distribution maps of the phosphor, from Figure 3 The sample exhibits an irregular blocky shape with an average size of 2.5 μm. Furthermore, EDS results show that Y, Ga, B, O, and Er elements are uniformly distributed on the particle surface, further confirming the presence of Er. 3+ Successfully incorporated into the crystal lattice. Figure 4 and Figure 5 Y, as described in Embodiment 1 of the present invention 0.95 Ga3(BO3)4: 0.05Er 3+ Emission spectra of phosphors under excitation at 365 nm and 980 nm, from Figure 4 and Figure 5 It can be seen that the samples exhibit narrow-band near-infrared emission of 1528 nm under excitation at 365 nm or 980 nm.

[0038] Example 2 A method for preparing a borate-based near-infrared luminescent material includes the following steps: According to the elemental stoichiometry of Y:Ga:B:Er, weigh out the raw materials as follows: 0.3915 g Y(NO3)3·6H2O, 0.2916 g Ga2O3, 0.2748 g H3BO3, and 0.0410 g Er(NO3)3·6H2O. Grind the above raw materials in a mortar for 15 minutes to make them uniformly mixed. Put the mixed powder into a mold and then put it into a powder tablet press for tableting to obtain the bulk material. The bulk material was transferred to a crucible, which was then placed in a muffle furnace. The crucible was heated to 950 °C at a heating rate of 10 °C / min in air and sintered for 4 h. Afterward, it was slowly cooled to room temperature to obtain Y. 0.92 Ga3(BO3)4: 0.08Er 3+ Near-infrared phosphor (borate-based near-infrared luminescent material).

[0039] Figure 6 and Figure 7 Y, as described in Embodiment 2 of the present invention 0.92 Ga3(BO3)4: 0.08Er3+ Emission spectra of phosphors under excitation at 365 nm and 980 nm, from Figure 6 and Figure 7 It can be seen that the samples exhibit narrow-band near-infrared emission of 1528 nm under excitation at 365 nm or 980 nm.

[0040] Example 3 A method for preparing a borate-based near-infrared luminescent material includes the following steps: According to the elemental stoichiometry of Y:Ga:B:Er, weigh out the raw materials as follows: 0.3745 g Y(NO3)3·6H2O, 0.2916 g Ga2O3, 0.2748 g H3BO3, and 0.0615 g Er(NO3)3·6H2O. Grind the above raw materials in a mortar for 15 minutes to make them uniformly mixed. Put the mixed powder into a mold and then put it into a powder tablet press for tableting to obtain the bulk material. The bulk material was transferred to a crucible, which was then placed in a muffle furnace. The crucible was heated to 970 °C at a heating rate of 10 °C / min in air and sintered for 4 h. Afterward, it was slowly cooled to room temperature to obtain Y. 0.88 Ga3(BO3)4: 0.12Er 3+ Near-infrared phosphor (borate-based near-infrared luminescent material).

[0041] Figure 8 and Figure 9 Y, as described in Embodiment 3 of the present invention 0.88 Ga3(BO3)4: 0.12Er 3+ Emission spectra of phosphors under excitation at 365 nm and 980 nm, from Figure 8 and Figure 9 It can be seen that the samples exhibit narrow-band near-infrared emission of 1528 nm under excitation at 365 nm or 980 nm.

[0042] Example 4 A method for preparing a borate-based near-infrared luminescent material includes the following steps: According to the elemental stoichiometry of Y:Ga:B:Er, weigh out the raw materials as follows: 0.3617 g Y(NO3)3·6H2O, 0.2916 g Ga2O3, 0.2748 g H3BO3, and 0.0769 g Er(NO3)3·6H2O. Grind the above raw materials in a mortar for 15 minutes to make them uniformly mixed. Put the mixed powder into a mold and then put it into a powder tablet press for tableting to obtain the bulk material. The bulk material was transferred to a crucible, which was then placed in a muffle furnace. The crucible was heated to 1000 °C at a heating rate of 10 °C / min under air atmosphere and sintered for 6 h. Afterward, it was slowly cooled to room temperature to obtain Y. 0.85 Ga3(BO3)4: 0.15Er 3+ Near-infrared phosphor (borate-based near-infrared luminescent material).

[0043] Figure 10 and Figure 11 Y, as described in Embodiment 4 of the present invention 0.85 Ga3(BO3)4: 0.15Er 3+ Emission spectra of phosphors under excitation at 365 nm and 980 nm, from Figure 10 and Figure 11 It can be seen that the samples exhibit narrow-band near-infrared emission of 1528 nm under excitation at 365 nm or 980 nm.

[0044] Example 5 A method for preparing a borate-based near-infrared luminescent material includes the following steps: According to the elemental stoichiometry ratio of Y:Ga:B:Er 0.82:3:4:0.18, the raw materials were weighed as follows: 0.1834 g Y2(CO3)3, 0.3515 g Ga2O3, 0.3092 g H3BO3, and 0.1038 g Er(NO3)3·6H2O. The above raw materials were placed in a mortar and ground for 15 min to make them uniformly mixed. The mixed powder was placed in a mold and then placed in a powder tablet press for tableting to obtain the bulk material. The bulk material was transferred to a crucible, which was then placed in a muffle furnace. The crucible was heated to 1020 °C at a heating rate of 10 °C / min under air atmosphere and sintered for 6 h. Afterward, it was slowly cooled to room temperature to obtain Y. 0.82 Ga3(BO3)4: 0.18Er 3+ Near-infrared phosphor (borate-based near-infrared luminescent material).

[0045] Figure 12 and Figure 13 Y, as described in Embodiment 5 of the present invention 0.82 Ga3(BO3)4: 0.18Er 3+ Emission spectra of phosphors under excitation at 365 nm and 980 nm, from Figure 12 and Figure 13 It can be seen that the samples exhibit narrow-band near-infrared emission of 1528 nm under excitation at 365 nm or 980 nm.

[0046] Example 6 A method for preparing a borate-based near-infrared luminescent material includes the following steps: According to the elemental stoichiometry ratio of Y:Ga:B:Er 0.8:3:4:0.2, weigh out the raw materials respectively: 0.2863 g Y2(CO3)3, 0.5623 g Ga2O3, 0.2785 g B2O3, and 0.0765 g Er2O3. Place the above raw materials in a mortar and grind for 30 minutes to make them uniformly mixed. Put the mixed powder into a mold, and then put it into a powder tablet press for tableting to obtain the bulk material. The bulk material was transferred to a crucible, which was then placed in a muffle furnace and heated to 1050 °C at a heating rate of 5 °C / min in air for 6 h. The mixture was then slowly cooled to room temperature to obtain Y. 0.8 Ga3(BO3)4: 0.2Er 3+ Near-infrared phosphor (borate-based near-infrared luminescent material).

[0047] Figure 14 and Figure 15 Y, as described in Embodiment 6 of the present invention 0.8 Ga3(BO3)4: 0.2Er 3+ Emission spectra of phosphors under excitation at 365 nm and 980 nm, from Figure 14 and Figure 15 It can be seen that the samples exhibit narrow-band near-infrared emission of 1528 nm under excitation at 365 nm or 980 nm.

[0048] Example 7 A method for preparing a borate-based near-infrared luminescent material includes the following steps: According to the elemental stoichiometry ratio of Y:Ga:B:Er 0.75: 3: 4: 0.25, the raw materials are weighed as follows: 0.2237 g Y2(CO3)3, 0.4686 g Ga2O3, 0.2321 g B2O3, and 0.0797 g Er2O3. The above raw materials are placed in a mortar and ground for 30 minutes to make them uniformly mixed. The mixed powder is placed in a mold and then placed in a powder tablet press for tableting to obtain the bulk material. The bulk material was transferred to a crucible, which was then placed in a muffle furnace and heated to 1050 °C at a heating rate of 5 °C / min in air for 6 h. The mixture was then slowly cooled to room temperature to obtain Y. 0.75 Ga3(BO3)4: 0.25Er 3+ Near-infrared phosphor (borate-based near-infrared luminescent material).

[0049] Figure 16 and Figure 17Y, as described in Embodiment 7 of the present invention 0.75 Ga3(BO3)4: 0.25Er 3+ Emission spectra of phosphors under excitation at 365 nm and 980 nm, from Figure 16 and Figure 17 It can be seen that the samples exhibit narrow-band near-infrared emission of 1528 nm under excitation at 365 nm or 980 nm.

[0050] Figure 18 Y in Examples 1-7 1-x Ga3(BO3)4: xEr 3+ XRD patterns of (0.05≤x≤0.25) phosphors and standard YGa3(BO3)4 cards, from Figure 18 It can be known that Y 3+ (r=1.011Å) and Er 3+ (r=1.004Å) have the same valence state and similar ionic radii, Er 3+ They will tend to occupy Y 3+ The position of the diffraction peaks of the obtained sample is basically consistent with that of the YGa3(BO3)4 standard card (PDF#04-002-9354), indicating that the YGa3(BO3)4 phase has been successfully synthesized.

[0051] Figure 19 Y in embodiments 1-7 of the present invention 1-x Ga3(BO3)4: xEr 3+ (0.05≤x≤0.25) The fluorescence intensity of the phosphor under 365nm excitation varies with Er 3+ The trend graph of doping content changes, from Figure 19 It can be seen that under 365 nm excitation, all samples exhibit narrow-band near-infrared emission at 1528 nm. With Er... 3+ With increasing doping content, the emission intensity of the sample first increases and then decreases. 3+ When the doping concentration is 20%, the emission intensity reaches its maximum value, and then decreases due to the concentration quenching effect.

[0052] Figure 20 Y in embodiments 1-7 of the present invention 1-x Ga3(BO3)4: xEr 3+ (0.05≤x≤0.25) The fluorescence intensity of the phosphor under 980nm excitation varies with Er 3+ The trend graph of doping content changes, from Figure 20 It can be seen that under 980 nm excitation, all samples exhibit narrow-band near-infrared emission at 1528 nm. With Er... 3+With increasing doping content, the emission intensity of the sample generally shows a trend of first increasing and then decreasing. When Er 3+ The emission intensity reaches its maximum value when the doping concentration is 20%.

[0053] Example 8 Since Ga2O3 impurity phases exist in Examples 1 to 7, the amount of Ga2O3 added will be reduced in this example in order to avoid the formation of Ga2O3 impurity phases. A method for preparing a borate-based near-infrared fluorescent material includes the following steps: According to the elemental stoichiometry of Y:Ga:B:Er, weigh out the raw materials as follows: 0.2681 g Y2O3, 0.3515 g Ga2O3, 0.3481 g B2O3, and 0.0239 g Er2O3. Place the raw materials in a mortar and grind them for 30 minutes to make them uniformly mixed. Put the mixed powder into a mold and then put it into a powder tablet press for tableting to obtain the bulk material. The bulk material was transferred to a crucible, which was then placed in a muffle furnace and heated to 1000 °C at a heating rate of 5 °C / min for 8 h in air. After sintering, the material was slowly cooled to room temperature to obtain Y. 0.95 Ga3(BO3)4: 0.05Er 3+ Near-infrared phosphor (borate-based near-infrared luminescent material).

[0054] Example 9 Since Ga2O3 impurity phases exist in Examples 1 to 7, the amount of Ga2O3 added will be reduced in this example in order to avoid the formation of Ga2O3 impurity phases. A method for preparing a borate-based near-infrared fluorescent material includes the following steps: According to the elemental stoichiometry ratio of Y:Ga:B:Er 0.95: 1.1: 4: 0.05, the raw materials are weighed separately: 0.2145 g Y2O3, 0.4124 g Ga2O3, 0.2785 g B2O3, and 0.0191 g Er2O3. The above raw materials are placed in a mortar and ground for 30 minutes to make them uniformly mixed. The mixed powder is placed in a mold and then placed in a powder tablet press for tableting to obtain the bulk material. The bulk material was transferred to a crucible, which was then placed in a muffle furnace and heated to 1000 °C at a heating rate of 5 °C / min for 8 h in air. After sintering, the material was slowly cooled to room temperature to obtain Y. 0.95 Ga3(BO3)4: 0.05Er 3+ Near-infrared phosphor (borate-based near-infrared luminescent material).

[0055] Example 10 Since Ga2O3 impurity phases exist in Examples 1 to 7, the amount of Ga2O3 added will be reduced in this example in order to avoid the formation of Ga2O3 impurity phases. A method for preparing a borate-based near-infrared fluorescent material includes the following steps: According to the elemental stoichiometry ratio of Y:Ga:B:Er 0.95: 1.1: 4: 0.05, the raw materials are weighed separately: 0.2145 g Y2O3, 0.5623 g Ga2O3, 0.2785 g B2O3, and 0.0191 g Er2O3. The above raw materials are placed in a mortar and ground for 30 minutes to make them uniformly mixed. The mixed powder is placed in a mold and then placed in a powder tablet press for tableting to obtain the bulk material. The bulk material was transferred to a crucible, which was then placed in a muffle furnace and heated to 1000 °C at a heating rate of 5 °C / min for 8 h in air. After sintering, the material was slowly cooled to room temperature to obtain Y. 0.95 Ga3(BO3)4: 0.05Er 3+ Near-infrared phosphor (borate-based near-infrared luminescent material).

[0056] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A borate-based near-infrared luminescent material, characterized by, The chemical general formula of the borate-based near-infrared luminescent material is Y 1-x Ga3(BO3)4:xEr 3+ wherein 0.05≤x≤0.

25.

2. The borate-based near-infrared luminescent material according to claim 1, characterized in that, The borate-based near-infrared luminescent material emits a peak in the range of 1400-1700 nm under excitation at a wavelength of 365 nm or 980 nm, and the emission center is at 1528 nm, belonging to the near-infrared 2 region emission.

3. The method for preparing a borate-based near-infrared luminescent material according to claim 1 or 2, characterized in that, The method comprises the following steps: The raw materials are weighed according to the molar ratio of each element in the chemical formula, mixed and ground to obtain a mixed powder, the mixed powder is pressed into a tablet to obtain a bulk material, and the bulk material is subjected to sintering treatment to obtain the borate-based near-infrared luminescent material.

4. The method for preparing a borate-based near-infrared luminescent material according to claim 3, characterized in that, The raw materials are a Y-containing precursor, a Ga-containing precursor, a B-containing precursor and an Er-containing precursor.

5. The method for preparing a borate-based near-infrared luminescent material according to claim 4, characterized in that, The Y-containing precursor is any one of Y(NO3)3·6H2O, Y2(CO3)3 and Y2O3 or a mixture of two or more thereof in any ratio.

6. The method for preparing a borate-based near-infrared luminescent material according to claim 4, characterized in that, The Ga-containing precursor is Ga2O3. The B-containing precursor is a mixture of any one of H3BO3 and B2O3 or both in any ratio.

7. The method for preparing a borate-based near-infrared luminescent material according to claim 4, characterized in that, The Er-containing precursor is a mixture of any one of Er(NO3)3·6H2O and Er2O3 or both in any ratio.

8. A method for preparing a borate-based near-infrared luminescent material according to claim 3, characterized in that, The mixing and grinding time is 15-30 min.

9. A method for preparing a borate-based near-infrared luminescent material according to claim 3, characterized in that, The sintering treatment has a heating rate of 5-10 ℃ / min, a sintering temperature of 950-1050 ℃ and a sintering time of 4-8 h.

10. Use of the borate-based near-infrared luminescent material according to claim 1 or 2 in a near-infrared fluorescent powder conversion type LED device.

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