A cr-based short-wave infrared luminescent material, a preparation method and application thereof

Abstract

The application discloses a Cr-based short-wave infrared luminescent material and a preparation method and application thereof, and belongs to the technical field of short-wave infrared luminescent materials.The Cr-based short-wave infrared luminescent material provided by the application has a chemical formula shown in formula (I): CrP3O9:xYb 3+ Formula (I); wherein, 0.001 3+ The Cr-based short-wave infrared luminescent material provided by the application can be effectively excited by blue-violet light (370-535 nm, excitation peak value-450 nm) and deep red light (550-750 nm, excitation peak value-650 nm), and can generate light emission in the short-wave infrared region (900-1200 nm) after excitation, so that the application range of short-wave infrared pc-LED technology can be effectively expanded; meanwhile, the material has the characteristics of excellent crystallinity, good thermal stability, high luminescent intensity and high external quantum yield, and the internal quantum efficiency and the external quantum efficiency can be up to 95.7% and 60.3% respectively; the preparation method is simple and environment-friendly, has low requirements on equipment and does not need atmosphere protection, no by-product is generated in the production process, is suitable for large-scale industrial production, and has a good application prospect.

Description

Technical Field

[0001] This invention relates to the field of short-wave infrared luminescent materials, and in particular to a Cr-based short-wave infrared luminescent material, its preparation method, and its applications. 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] Fluorescent conversion LEDs (pc-LEDs) are hailed as a new generation of light sources due to their advantages of energy saving, environmental friendliness, high efficiency, and long lifespan. Currently, the demand for small, economical, and thermally stable novel short-wave infrared light sources (900–1600 nm) is increasing in fields such as optical anti-counterfeiting, night vision identification, food safety, and biomedicine. There is a growing expectation to develop a pc-LED device capable of achieving efficient short-wave infrared emission.

[0004] With the continuous development of blue light (450-460nm) InGaN chips, exploring fluorescent materials that can be excited by blue light for the fabrication of pc-LEDs has become a research hotspot in the field of luminescent materials. 3+ Ions can produce highly tunable deep red and infrared light (700–1000 nm) under blue light excitation. Because their absorption range matches the emission band of commercial InGaN chips, they are often used to prepare short-wave infrared phosphors. However, their emission spectrum still has significant room for expansion compared to the InGaAs infrared detector range (900–1700 nm). To obtain more comprehensive material analysis capabilities, it is necessary to develop short-wave infrared phosphors with longer wavelengths. To obtain emission peaks above 1000 nm, other ions capable of producing short-wave infrared emission, such as Ni... 2 + 、Nd 3+ Yb 3+ Equal to Cr 3+ Ion co-doping is one of the main design strategies for developing broadband inorganic light-emitting materials. However, many reported light-emitting materials that achieve broadband short-wave infrared emission through the above methods have low external quantum efficiency and absorption efficiency, and the photoelectric conversion efficiency of the encapsulated LED devices needs to be further improved.

[0005] Therefore, developing short-wave infrared luminescent materials with high external quantum efficiency under blue light excitation is an important issue in the development of next-generation short-wave infrared light source technology and its applications. It has significant research significance and application value for the development of short-wave infrared light sources and spectroscopy technology. Summary of the Invention

[0006] In view of this, the present invention provides a Cr-based short-wave infrared luminescent material, its preparation method and application, which solves the problem of low external quantum efficiency and absorption efficiency of existing broadband short-wave infrared luminescent materials. The short-wave infrared luminescent material provided by the present invention has stable chemical properties, can be effectively excited by blue or red light, has an emission peak at around 1000 nm, and has internal and external quantum efficiencies of up to 95.7% and 60.3% respectively, and has broad application value in the field of short-wave infrared light sources.

[0007] In a first aspect, the present invention provides a Cr-based short-wave infrared luminescent material having the chemical formula shown in formula (I):

[0008] CrP3O9:xYb 3+ Formula (I);

[0009] Where 0.001 < x ≤ 0.2, Cr is represented by Cr 3+ The valence state exists.

[0010] Preferably, 0.01 < x ≤ 0.1.

[0011] Preferably, the Cr-based short-wave infrared emitting material is selected from CrP3O9:0.01Yb. 3+ CrP3O9:0.03Yb 3+ CrP3O9:0.05Yb 3+ CrP3O9:0.07Yb 3+ Or CrP3O9:0.09Yb 3+ .

[0012] More preferably, the Cr-based short-wave infrared luminescent material is selected from CrP3O9:0.05Yb. 3+ .

[0013] Secondly, the present invention provides a method for preparing the above-mentioned Cr-based short-wave infrared luminescent material, comprising the following steps:

[0014] Yb source, P source and Cr source are mixed evenly in proportion, pre-fired at low temperature, cooled to room temperature and then sintered at high temperature to obtain Cr-based short-wave infrared luminescent material, wherein the amount of P source is 130 to 150% of the theoretical molar amount.

[0015] Preferably, the Yb source is selected from ytterbium oxide or ytterbium nitrate; the P source is selected from ammonium dihydrogen phosphate or diammonium hydrogen phosphate; and the Cr source is selected from chromium nitrate, chromium chloride or chromium oxide.

[0016] Preferably, the temperature of the low-temperature preheating is 500-600°C, and the low-temperature preheating time is 2-5 hours.

[0017] Preferably, the high-temperature sintering temperature is 1000–1400°C, and the high-temperature sintering time is 5–10 hours.

[0018] Preferably, both the low-temperature pre-firing and the high-temperature sintering are carried out in an air atmosphere.

[0019] Thirdly, the present invention provides a fluorescence-converting short-wave infrared LED device, wherein the short-wave infrared LED device includes at least an excitation light source and a phosphor, and the phosphor includes at least the above-mentioned Cr-based short-wave infrared luminescent material.

[0020] Preferably, the excitation light source is a blue light chip with an emission wavelength range of 440–500 nm; the fluorescence conversion type short-wave infrared LED device emits short-wave infrared light in the range of 900–1200 nm.

[0021] Fourthly, the present invention provides applications of the above-mentioned fluorescence-converting short-wave infrared LED device in optical anti-counterfeiting, non-destructive testing, night vision lighting, food safety, or biomedical fields.

[0022] Compared with the prior art, the present invention has achieved the following beneficial effects:

[0023] (1) The Cr-based short-wave infrared luminescent material provided by the present invention can be effectively excited by blue-violet light (370-535nm, excitation peak ~450nm) and deep red light (550-750nm, excitation peak ~650nm). After excitation, it can emit light in the short-wave infrared region (900-1200nm), with emission peaks at 966nm, 1003nm and 1054nm, and a half-peak width of ~58nm, which can effectively expand the application range of short-wave infrared pc-LED technology.

[0024] (2) The short-wave infrared luminescent material provided by the present invention has excellent performance, with excellent crystallinity, good thermal stability, high luminescence intensity and high external quantum yield, and the internal and external quantum efficiencies can reach up to 95.7% and 60.3%, respectively.

[0025] (3) The preparation method of the present invention is simple and environmentally friendly, has low requirements for equipment and does not require atmosphere protection. No by-products are generated in the production process, making it suitable for large-scale industrial production and with good application prospects.

[0026] (4) The fluorescent conversion type short-wave infrared LED device constructed by the present invention can emit short-wave infrared light that matches the current current intensity under different currents. It can be used in optical anti-counterfeiting, non-destructive testing, night vision lighting, food safety and biomedicine, and has broad application prospects. 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 The X-ray diffraction pattern of the Cr-based short-wave infrared luminescent material prepared in Example 1 of this invention;

[0029] Figure 2 The excitation and emission spectra of the Cr-based short-wave infrared luminescent material prepared in Example 1 of this invention are shown.

[0030] Figure 3 The excitation and emission spectra of the Cr-based short-wave infrared luminescent material prepared in Example 2 of this invention are shown.

[0031] Figure 4 The X-ray diffraction pattern of the Cr-based short-wave infrared luminescent material prepared in Example 3 of this invention;

[0032] Figure 5 The excitation and emission spectra of the Cr-based short-wave infrared luminescent material prepared in Example 3 of this invention are shown.

[0033] Figure 6 The fluorescence quantum yield of the Cr-based short-wave infrared luminescent material prepared in Example 3 of this invention is measured using a BaSO4 standard sample as a reference.

[0034] Figure 7 The short-wave infrared LED device prepared in this embodiment 3 is shown in (a) when no power is applied and (b) when power is applied.

[0035] Figure 8 The excitation and emission spectra of the short-wave infrared LED device prepared in Example 3 of this invention under different currents;

[0036] Figure 9 This is a schematic diagram illustrating the application of the short-wave infrared LED device prepared in Embodiment 3 of the present invention in the field of information hiding and reading.

[0037] Figure 10 The X-ray diffraction pattern of the Cr-based short-wave infrared luminescent material prepared in Example 4 of this invention;

[0038] Figure 11 The excitation and emission spectra of the Cr-based short-wave infrared luminescent material prepared in Example 4 of this invention are shown.

[0039] Figure 12 The X-ray diffraction pattern of the Cr-based short-wave infrared luminescent material prepared in Example 5 of this invention;

[0040] Figure 13 The excitation and emission spectra of the Cr-based short-wave infrared luminescent material prepared in Example 5 of this invention are shown. Detailed Implementation

[0041] 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.

[0042] This invention provides a Cr-based short-wave infrared luminescent material having the chemical formula shown in formula (I):

[0043] CrP3O9:xYb 3+ Formula (I);

[0044] Where 0.001 < x ≤ 0.2, Cr is represented by Cr 3+ The valence state exists.

[0045] In this invention, x is Yb 3+ The molar percentage of doping amount relative to CrP3O9. When the types or contents of elements Cr, P, O, and Yb vary or exceed the range or ratio specified in this invention, the prepared material will have low phase purity, weak luminescence intensity, poor thermal stability, and weakened short-wave infrared luminescence performance, thus lacking economic and practical value.

[0046] Preferably, in this invention, 0.01 < x ≤ 0.1. For example, the Cr-based short-wave infrared emitting material can be selected from CrP3O9:0.01Yb. 3+ CrP3O9:0.03Yb 3+ CrP3O9:0.05Yb 3+ CrP3O9:0.07Yb 3+ Or CrP3O9:0.09Yb 3+ Etc. Most preferably, the Cr-based short-wave infrared emitting material is CrP3O9:0.05Yb. 3+ .

[0047] This invention also provides a method for preparing the above-mentioned Cr-based short-wave infrared luminescent material, comprising the following steps:

[0048] Yb, P, and Cr sources are mixed uniformly in a specific ratio, pre-fired at a low temperature, cooled to room temperature, and then sintered at a high temperature to obtain a Cr-based short-wave infrared luminescent material. The amount of P source used is 130–150% of the theoretical molar amount, more preferably 140–145%, to reduce residual Cr-containing compound impurities due to incomplete reaction of the raw materials. The amounts of Yb and Cr sources need to be determined based on the molar ratio of each element in the chemical formula of the short-wave infrared luminescent material.

[0049] The present invention does not impose any special restrictions on the mixing process of Yb source, P source and Cr source in proportion to achieve uniform mixing. Grinding, ball milling, stirring or other common mixing methods can be used for mixing. The present invention prefers grinding mixing, with a grinding time of 10 to 25 minutes, more preferably 15 to 25 minutes.

[0050] In this invention, the Yb source is selected from ytterbium oxide or ytterbium nitrate. To reduce the shrinkage rate of the material and improve its purity, thereby enhancing its luminescence performance, the Yb source is more preferably ytterbium oxide. The P source is selected from ammonium dihydrogen phosphate or diammonium hydrogen phosphate. To reduce the shrinkage rate of the material and improve its crystallinity, thereby enhancing its luminescence performance, the P source is more preferably ammonium dihydrogen phosphate. The Cr source is selected from chromium nitrate, chromium chloride, or chromium oxide. To reduce the shrinkage rate of the material and enhance its luminescence performance, the Cr source is more preferably chromium oxide.

[0051] In this invention, low-temperature pre-calcination can effectively remove volatile components from the raw materials, such as surface-absorbed moisture or NH3 produced by the decomposition of ammonium dihydrogen phosphate. Simultaneously, precursor reactions can occur during low-temperature pre-calcination, allowing components that are volatile or decompose at high temperatures to decompose uniformly or react completely at low temperatures. Therefore, combining low-temperature pre-calcination with high-temperature sintering is beneficial for obtaining the desired compound and improving the luminescent properties of the material.

[0052] In this invention, the temperature of the low-temperature preheating is 500-600℃, more preferably 530-570℃, further preferably 540-560℃, and most preferably 550℃; the low-temperature preheating time is 2-5h, more preferably 3-5h, and most preferably 4h.

[0053] In this invention, the high-temperature sintering temperature is 1000-1400℃, more preferably 1100-1300℃, and most preferably 1200℃; the high-temperature sintering time is 5-10h, more preferably 7-9h, and most preferably 8h.

[0054] The low-temperature pre-firing and high-temperature sintering described in this invention are both carried out in an air atmosphere, without the need for inert gas protection or in a vacuum.

[0055] The present invention also provides a fluorescence-converting short-wave infrared LED device, wherein the short-wave infrared LED device includes at least an excitation light source and a phosphor, and the phosphor includes at least the above-mentioned Cr-based short-wave infrared luminescent material.

[0056] In this invention, the excitation light source is a blue light chip with an emission wavelength range of 440–500 nm; the fluorescence-converting short-wave infrared LED device emits short-wave infrared light in the range of 900–1200 nm. The Cr-based short-wave infrared luminescent material prepared in this invention can produce strong emission in the short-wave infrared region (900–1300 nm) under excitation by a 450 nm blue light LED chip, with emission peaks located at ~966 nm, ~1003 nm, and ~1054 nm, and a full width at half maximum (FWHM) of ~58 nm. Therefore, the material prepared in this invention is suitable for use in blue light chips.

[0057] This invention does not impose any special limitations on the assembly method of the fluorescence-converting short-wave infrared LED device; any assembly method commonly used by those skilled in the art for fluorescence-converting short-wave infrared LED devices can be employed. Preferably, in this invention, phosphor containing Cr-based short-wave infrared luminescent material is uniformly dispersed in transparent silicone, and the blue light chip is then combined with the phosphor-containing silicone to obtain the final product.

[0058] This invention also provides applications of the above-mentioned fluorescence-converting short-wave infrared LED device in optical anti-counterfeiting, non-destructive testing, night vision lighting, food safety, or biomedical fields.

[0059] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0060] Example 1

[0061] This embodiment provides a Cr-based short-wave infrared luminescent material CrP3O9:0.01Yb. 3+ Preparation method of .

[0062] According to the following composition: short-wave infrared emitting material CrP3O9:0.01Yb 3+ Using CrP3O9 as the matrix and Yb 3+ As dopant ions to broaden the emission spectrum, the doping amount was 1 mol%. Accurately weigh 0.0047 g (0.0119 mmol) of ytterbium oxide (Yb₂O₃), 1.1895 g (10.3407 mmol) of ammonium dihydrogen phosphate (NH₄H₂PO₄), and 0.1815 g (1.1943 mmol) of chromium oxide (Cr₂O₃). Grind the above raw materials in an agate mortar for approximately 20 minutes to ensure thorough mixing. Then transfer the mixture to a corundum crucible and pre-calcine at 550°C for 4 hours. After pre-calcination, the powder was re-ground and then sintered in the corundum crucible at 1200°C for 8 hours to obtain blue light-excited CrP₃O₉:0.01Yb₂O₃.3+ Short-wave infrared luminescent materials.

[0063] The samples prepared in this embodiment were tested.

[0064] See the X-ray diffraction pattern of the sample. Figure 1 The results were consistent with the standard diffraction pattern of CrP3O9, indicating that the synthesized sample was a pure phase with no other impurities generated.

[0065] See the excitation and emission spectra of the sample. Figure 2 The emission at 1003 nm was monitored. The excitation wavelength range of the sample was between 270 and 750 nm, with excitation peaks at 300 nm, 450 nm and 660 nm, respectively. Under 450 nm blue light excitation, the short-wave infrared emission of the sample was located between 900 and 1200 nm, with emission peaks at 966 nm, 1003 nm and 1054 nm, respectively.

[0066] Example 2

[0067] This embodiment provides a Cr-based short-wave infrared luminescent material CrP3O9:0.03Yb 3+ Preparation method of .

[0068] According to the following composition: short-wave infrared emitting material CrP3O9:0.03Yb 3+ Using CrP3O9 as the matrix and Yb 3+ As dopant ions to broaden the emission spectrum, the doping amount was 3 mol%. Accurately weigh 0.01415 g (0.0359 mmol) of ytterbium oxide (Yb₂O₃), 1.1796 g (10.2547 mmol) of ammonium dihydrogen phosphate (NH₄H₂PO₄), and 0.1764 g (1.1606 mmol) of chromium oxide (Cr₂O₃). Grind the above raw materials in an agate mortar for approximately 20 minutes to ensure thorough mixing. Then transfer the mixture to a corundum crucible and pre-calcine at 550°C for 4 hours. After pre-calcination, the powder was re-ground and then sintered in the corundum crucible at 1200°C for 8 hours to obtain blue light-excited CrP₃O₉:0.03Yb₂O₃. 3+ Short-wave infrared luminescent materials.

[0069] The samples prepared in this embodiment were tested.

[0070] See the excitation and emission spectra of the sample. Figure 3 The emission at 1003 nm was monitored. The excitation wavelength range of the sample was between 270 and 750 nm, with excitation peaks at 300 nm, 450 nm and 660 nm, respectively. Under 450 nm blue light excitation, the short-wave infrared emission of the sample was between 900 and 1200 nm, with emission peaks at 966 nm, 1003 nm and 1052 nm, respectively.

[0071] Example 3

[0072] This embodiment provides a Cr-based short-wave infrared luminescent material CrP3O9:0.05Yb. 3+ Preparation method of .

[0073] According to the following composition: short-wave infrared emitting material CrP3O9:0.05Yb 3+ Using CrP3O9 as the matrix and Yb 3+ As dopant ions to broaden the emission spectrum, the doping amount was 5 mol%. Accurately weigh 0.0234 g (0.0594 mmol) of ytterbium oxide (Yb₂O₃), 1.1700 g (10.1709 mmol) of ammonium dihydrogen phosphate (NH₄H₂PO₄), and 0.1713 g (1.1271 mmol) of chromium oxide (Cr₂O₃). Grind the above raw materials in an agate mortar for approximately 20 minutes to ensure thorough mixing. Then transfer the mixture to a corundum crucible and pre-calcine at 550°C for 4 hours. After pre-calcination, the powder was re-ground and then sintered in the corundum crucible at 1200°C for 8 hours to obtain blue light-excited CrP₃O₉:0.05Yb₂O₃. 3+ Short-wave infrared luminescent materials.

[0074] The samples prepared in this embodiment were tested.

[0075] See the X-ray diffraction pattern of the sample. Figure 4 The results were consistent with the standard diffraction pattern of CrP3O9, indicating that the synthesized sample was a pure phase with no other impurities generated.

[0076] See the excitation and emission spectra of the sample. Figure 5 The emission at 1003 nm was monitored. The excitation wavelength range of the sample was between 270 and 750 nm, with excitation peaks at 300 nm, 450 nm and 660 nm, respectively. Under 450 nm blue light excitation, the short-wave infrared emission of the sample was located between 900 and 1200 nm, with emission peaks at 966 nm, 1003 nm and 1054 nm, respectively.

[0077] See the fluorescence quantum yield detection graph of the sample. Figure 6 Under 450 nm blue light excitation, the sample exhibits an internal quantum yield of 95.7%, an absorption efficiency of 63.0%, and an external quantum yield of 60.3%.

[0078] See the sample and the short-wave infrared LED device fabricated by packaging a 450nm blue light chip. Figure 7 When the current is turned on, the device can generate short-wave infrared light emission.

[0079] The emission spectra of the fabricated short-wave infrared LED device under different currents are shown in [reference]. Figure 8 The intensity of the emission spectrum increases with increasing current.

[0080] See the schematic diagram for information hiding and reading of short-wave infrared LED devices and their application in non-destructive testing. Figure 9 .like Figure 9 As shown, when the short-wave infrared LED is turned on and a short-wave infrared camera is used for imaging, the text printed with ink containing a higher carbon black content completely absorbs the short-wave infrared light and does not produce any short-wave infrared light reflection, thus exhibiting a very low grayscale value. Other patterns, printed with ink containing less carbon black, exhibit a grayscale value similar to the background. Therefore, a short-wave infrared camera can be used to photograph content printed with different types of ink to obtain the true information, which can be applied in the fields of information hiding and retrieval.

[0081] Example 4

[0082] This embodiment provides a Cr-based short-wave infrared luminescent material CrP3O9:0.07Yb. 3+ Preparation method of .

[0083] According to the following composition: short-wave infrared emitting material CrP3O9:0.07Yb 3+ Using CrP3O9 as the matrix and Yb 3+ As dopant ions to broaden the emission spectrum, the doping amount was 7 mol%. Accurately weigh 0.0325 g (0.0824 mmol) of ytterbium oxide (Yb₂O₃), 1.1604 g (10.0881 mmol) of ammonium dihydrogen phosphate (NH₄H₂PO₄), and 0.1664 g (1.0948 mmol) of chromium oxide (Cr₂O₃). Grind the above raw materials in an agate mortar for approximately 20 minutes to ensure thorough mixing. Then transfer the mixture to a corundum crucible and pre-calcine at 550°C for 4 hours. After pre-calcination, the powder was re-ground and then sintered in the corundum crucible at 1200°C for 8 hours to obtain blue light-excited CrP₃O₉:0.07Yb₂O₃. 3+ Short-wave infrared luminescent materials.

[0084] The samples prepared in this embodiment were tested.

[0085] See the X-ray diffraction pattern of the sample. Figure 10 The main phase has a standard diffraction pattern consistent with CrP3O9, and the impurity phase YbP3O9 is present. However, the infrared luminescence intensity of the material is not weaker than that of the samples in the aforementioned examples, and it still has practical value.

[0086] See the excitation and emission spectra of the sample. Figure 11The emission at 1003 nm was monitored. The excitation wavelength range of the sample was between 270 and 750 nm, with excitation peaks at 300 nm, 450 nm and 660 nm, respectively. Under 450 nm blue light excitation, the short-wave infrared emission of the sample was between 900 and 1200 nm, with emission peaks at 967 nm, 1003 nm and 1054 nm, respectively.

[0087] Example 5

[0088] This embodiment provides a Cr-based short-wave infrared luminescent material CrP3O9:0.09Yb. 3+ Preparation method of .

[0089] According to the following composition: short-wave infrared emitting material CrP3O9:0.09Yb 3+ Using CrP3O9 as the matrix and Yb 3+ As dopant ions to broaden the emission spectrum, the doping amount was 9 mol%. Accurately weigh 0.0414 g (0.1051 mmol) of ytterbium oxide (Yb₂O₃), 1.1511 g (10.0067 mmol) of ammonium dihydrogen phosphate (NH₄H₂PO₄), and 0.1615 g (1.0624 mmol) of chromium oxide (Cr₂O₃). Grind the above raw materials in an agate mortar for approximately 20 minutes to ensure thorough mixing. Then transfer the mixture to a corundum crucible and pre-calcine at 550°C for 4 hours. After pre-calcination, the powder was re-ground and then sintered in the corundum crucible at 1200°C for 8 hours to obtain blue light-excited CrP₃O₉:0.09Yb₂O₃. 3+ Short-wave infrared luminescent materials.

[0090] The samples prepared in this embodiment were tested.

[0091] See the X-ray diffraction pattern of the sample. Figure 12 The main phase is consistent with the standard diffraction pattern of CrP3O9, and the impurity phase YbP3O9 is generated. The infrared luminescence intensity of the material is only slightly reduced compared with the aforementioned embodiments, and it still has practical value.

[0092] See the excitation and emission spectra of the sample. Figure 13 The emission at 1003 nm was monitored. The excitation wavelength range of the sample was between 250 and 750 nm, with excitation peaks at 300 nm, 450 nm and 662 nm, respectively. Under 450 nm blue light excitation, the short-wave infrared emission of the sample was located between 900 and 1200 nm, with emission peaks at 966 nm, 1003 nm and 1054 nm, respectively.

[0093] 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 Cr-based short-wave infrared luminescent material, characterized in that, The Cr-based short-wave infrared luminescent material has the chemical formula shown in formula (I): CrP3O9: x Yb 3+ Formula (I); Where, 0.001 < x ≤0.2, Cr as Cr 3+ Price states exist; The Cr-based short-wave infrared luminescent material can be effectively excited by blue-violet light and deep red light. After excitation, it can emit light in the short-wave infrared region, with emission peaks at 966 nm, 1003 nm and 1054 nm. The Cr-based short-wave infrared luminescent material has an internal and external quantum efficiency of up to 95.7% and 60.3%, respectively.

2. The Cr-based short-wave infrared luminescent material as described in claim 1, characterized in that, 0.01＜x≤0.1。 3. The Cr-based short-wave infrared luminescent material as described in claim 2, characterized in that, The Cr-based short-wave infrared luminescent material is selected from CrP3O9:0.03Yb. 3+ CrP3O9:0.05Yb 3+ CrP3O9:0.07Yb 3+ Or CrP3O9:0.09Yb 3+ .

4. The method for preparing the Cr-based short-wave infrared luminescent material according to any one of claims 1 to 3, characterized in that, Includes the following steps: Yb source, P source and Cr source are mixed evenly in proportion, pre-fired at low temperature, cooled to room temperature and then sintered at high temperature to obtain Cr-based short-wave infrared luminescent material, wherein the amount of P source is 130~150% of the theoretical molar amount.

5. The preparation method according to claim 4, characterized in that, The Yb source is selected from ytterbium oxide or ytterbium nitrate; the P source is selected from ammonium dihydrogen phosphate or diammonium hydrogen phosphate; and the Cr source is selected from chromium nitrate, chromium chloride or chromium oxide.

6. The preparation method according to claim 4, characterized in that, The low-temperature pre-firing temperature is 500~600℃, and the low-temperature pre-firing time is 2~5h; the high-temperature sintering temperature is 1000~1400℃, and the high-temperature sintering time is 5~10h.

7. The preparation method according to claim 4, characterized in that, Both the low-temperature pre-firing and high-temperature sintering are carried out in an air atmosphere.

8. A fluorescence-converting short-wave infrared LED device, characterized in that, The short-wave infrared LED device includes at least an excitation light source and a phosphor, wherein the phosphor includes at least the Cr-based short-wave infrared luminescent material as described in any one of claims 1 to 3.

9. The fluorescent conversion type short-wave infrared LED device as described in claim 8, characterized in that, The excitation light source is a blue light chip with an emission wavelength range of 440~500 nm; the fluorescence conversion type short-wave infrared LED device emits short-wave infrared light in the range of 900~1200 nm.

10. The application of the Cr-based short-wave infrared luminescent material as described in any one of claims 1 to 3 or the fluorescence-converting short-wave infrared LED device as described in any one of claims 8 to 9 in the fields of optical anti-counterfeiting, non-destructive testing, night vision lighting, food safety, or biomedicine.

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