Near-infrared luminescent material with high quantum efficiency as well as preparation technology and application of near-infrared luminescent material

Abstract

The invention provides a near-infrared luminescent material with high quantum efficiency as well as a preparation technology and application of the near-infrared luminescent material. The near-infrared luminescent material with high quantum efficiency can be represented by a chemical general formula of La2Nb (2-x) Sc (2-x) Cr2xO11-0.5 x (wherein x is greater than or equal to 0.001 and less than or equal to 0.01). The light absorption range of the near-infrared luminescent material is 250 nm to 490 nm; under excitation of 450 nm blue light, the near-infrared luminescent material can emit near-infrared light with the main peak between 1000 nm and 1020 nm and the full width at half maximum between 210 nm and 240 nm, and the quantum efficiency is larger than or equal to 90%. Compared with the prior art, the invention has the following beneficial effects: (1) the luminescent material has high tolerance to defects caused by charge imbalance; (2) the quantum efficiency of the obtained luminescent material is relatively high; and (3) the full width at half maximum of the emission spectrum of the luminescent material is relatively wide, and the luminescent material can absorb blue light, so that the luminescent material can be used for high-power near-infrared devices.

Description

Technical Field

[0001] The present invention relates to the technical field of luminescent materials, and in particular to a near-infrared luminescent material with high quantum efficiency and a preparation technology and application thereof. Background Art

[0002] Broadband near-infrared spectroscopy technology has broad application prospects in the fields of optical scanning, diagnosis and treatment, detection imaging and chemical composition detection. High-performance near-infrared light sources are the prerequisite for manufacturing the above-mentioned technical applications, and the industry has always been in urgent need of high-power near-infrared light sources. In recent years, fluorescence conversion near-infrared light sources based on blue light-emitting diodes and near-infrared luminescent materials have shown tunable, efficient, broadband near-infrared emission, becoming a research hotspot. However, the near-infrared luminescent materials used in fluorescent material conversion near-infrared light sources are subject to the problem of low quantum efficiency, and it is difficult to meet the needs of high-power fluorescent material conversion near-infrared light sources. Therefore, the development of efficient near-infrared inorganic luminescent materials and the realization of high-power broadband near-infrared light output are of great significance to the industrialization process of near-infrared spectroscopy technology.

[0003] At present, a variety of near-infrared fluorescent materials have been reported. For example, reference 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 phosphate-based phosphor material, the chemical expression of which is AB 1-x P2O7:xCr, wherein A is at least one of Li, Na, and K, and 0.01≤x≤0.1. The phosphor material is excited by visible light in the range of 400-520nm and 550-780nm, and emits broadband near-infrared light in the range of 750-1100nm. Comparative Document 2 (Lin Jintian, Du Fu, Chen Lei, Zhao Wen, Cai Yu, Li Jinyue, Near-infrared luminescent material, preparation method thereof, and luminescent device, CN113930243B) discloses a near-infrared luminescent material, characterized in that the chemical formula of the near-infrared luminescent material is A x D y O4:Rm; wherein A is Ga element; D is Nb element; R is Cr and Yb element; O is oxygen element; and 0<x≤1.2, 0<y≤1.2, 0.002≤m≤0.2, (x+m):y:4=1:1:4. In the near-infrared luminescent material, the element corresponding to R (such as Cr) replaces the element corresponding to A (such as Ga, instead of Nb corresponding to D element), and is located in the crystallographic octahedral position of the near-infrared luminescent material, and the molar content ratio of A occupied by it is not more than 20%. That is, as described in non-patent document 1 (Meijuan Zheng, Xiaoling Dong, Dan Wu, Yue Wang, WenpingZhou, Yifan Liu, Liangliang Zhang, Cr3+ and Y 3+ co-doped perovskite-like phosphor with improved thermal stability by efficient energy transfer, AIP Advances, 2024, 14, 055133) believes that: Generally speaking, due to Nb 5+ and Cr 3+ The difference in charge number between Cr 3+ It is difficult to replace Nb in the crystal structure 5+ .

[0004] Non-patent document 2 (You Panli, Li2BaSiO4:Sm 3+ Preparation and Performance Study of Phosphors, Acta Optica Sinica, 2015, 35(5):0516002) believes that defects will form fluorescence quenching centers, converting the absorbed energy into matrix lattice energy and releasing it in a non-radiative transition manner, thereby reducing the emission intensity of the phosphors. Non-patent document 3 (Jiang Mao, Zhang Dongliang, Defect Chemistry Theory and Its Development, Journal of South China Normal University·Natural Science Edition, 1994, 1, 74-79) believes that substitution between ions with different charge numbers will inevitably lead to charge imbalance, and charge imbalance will inevitably lead to defects. Therefore, as shown in non-patent document 4 (Xinmiao Yu, Zhendong Liu, Wentao Zhang, Xinru Xu, Haiying Du, Effect of A + (A=Li, Na and K)co-doping on enhancing the luminescence of Ca5(PO4)2SiO4:Eu 3+ Red-emitting phosphors as charge compensators, Ceramics International, 2021, 47, 3: 3540-3547) believe that the use of charge compensators can significantly reduce defects and improve the luminescence intensity of luminescent materials. Obviously, if the opposite is true, that is, if the defects caused by charge imbalance are artificially increased, it will inevitably cause the defects contained in the luminescent material to increase, reducing the intensity of the luminescent material.

[0005] In summary, the following predictions can be drawn from the currently available literature: (1) Generally speaking, Cr 3+ It is difficult to replace Nb 5+ ; (2). If Cr 3+ Replaced Nb 5+Due to the charge imbalance, the defects inside the material will inevitably increase, which will eventually reduce the luminescence performance of the material. Summary of the invention

[0006] One of the purposes of the present invention is to provide a near-infrared luminescent material with high quantum efficiency. The luminescent material can absorb light in the ultraviolet to blue light band and emit near-infrared light with a main peak between 1000nm and 1020nm, a half-width of the emission spectrum of 210nm to 240nm, and a quantum efficiency of ≥90%, so that the luminescent material can be used in high-power near-infrared light sources.

[0007] To achieve the above object, the present invention adopts the following technical solution:

[0008] A near-infrared luminescent material with high quantum efficiency, the chemical formula of the material is:

[0009] LqCy 2-x Sc 2-x Cr 2x O 11-0.5x , where 0.001≤x≤0.01.

[0010] The high quantum efficiency near-infrared luminescent material can absorb light within the range of 250nm to 490nm. Under the excitation of 450nm blue light, the main peak of the emission spectrum of the high quantum efficiency near-infrared luminescent material is located between 1000nm and 1020nm, the half-width of the emission spectrum is 210nm to 240nm, and the quantum efficiency is ≥90%.

[0011] Preferably, x may be 0.005.

[0012] The second object of the present invention is to provide a method for preparing a near-infrared luminescent material with high quantum efficiency. The preparation method comprises the following steps:

[0013] A) La precursor, Sc precursor and Cr precursor are mixed and subjected to high temperature solid phase reaction under reducing atmosphere to obtain a La2Sc 2-x Cr x Intermediates of O6, where 0.001≤x≤0.01;

[0014] B) Change the nominal composition to La2Sc 2-x Cr x The intermediate of O6, Nb precursor and Cr precursor are mixed and reacted at high temperature in air atmosphere to obtain a chemical formula which can be expressed as La2Nb 2-x Sc 2-x Cr 2x O 11-0.5x A near-infrared luminescent material with high quantum efficiency, wherein 0.001≤x≤0.01.

[0015] Preferably, x=0.005.

[0016] Preferably, in step A), the molar ratio of La, Sc and Cr in the La precursor, the Sc precursor and the Cr precursor is 2:(2-x):x, and the nominal composition of the intermediate is: La2Sc 2-x Cr x O6, where 0.001≤x≤0.01;

[0017] Preferably, in step B), the molar ratio of the intermediate, Nb to Cr in the intermediate, Nb precursor and Cr precursor is 1:(2-x):x, wherein 0.001≤x≤0.01.

[0018] Preferably, in step A), the precursor of La is selected from one or more of La carbonate, La oxide, La oxalate and La nitrate; the precursor of Sc is selected from Sc oxide, i.e. Sc2O3; the body of Cr is selected from one or more of Cr carbonate, Cr oxide, Cr oxalate and Cr nitrate. In step B), the precursor of Nb is selected from Nb oxide, i.e. Nb2O5; the body of Cr is selected from one or more of Cr carbonate, Cr oxide, Cr oxalate and Cr nitrate.

[0019] Preferably, the purity of the La precursor, the Nb precursor, the Sc precursor and the Cr precursor is not less than 99.5%.

[0020] Preferably, in the step A), the reducing atmosphere is ammonia or a nitrogen-hydrogen mixed gas, the temperature of the high-temperature solid phase reaction is 1400-1600° C., and the time of the high-temperature solid phase reaction is between 4 and 10 hours.

[0021] Preferably, in step B), under air atmosphere, the temperature of the high temperature solid phase reaction is between 1500 and 1700° C., and the time of the high temperature solid phase reaction is between 4 and 10 hours.

[0022] The third object of the present invention is to provide a near-infrared light-emitting device, the light-emitting device comprises a light-emitting diode and a light-emitting material, wherein the light-emitting diode can emit light with a wavelength range of 380nm to 480nm, and the light-emitting material at least comprises a chemical formula represented by La2Nb 2-x Sc 2-x Cr 2x O 11-0.5x (where 0.001≤x≤0.01) high quantum efficiency near-infrared luminescent material.

[0023] The specific plan is as follows:

[0024] A) La precursor, Sc precursor and Cr precursor are mixed and subjected to high temperature solid phase reaction under reducing atmosphere to obtain a La2Sc 2-x Cr x Intermediates of O6, where 0.001≤x≤0.01;

[0025] B) Change the nominal composition to La2Sc 2-x Cr x The intermediate of O6, Nb precursor and Cr precursor are mixed and reacted at high temperature in air atmosphere to obtain a chemical formula which can be expressed as La2Nb 2-x Sc 2-x Cr 2x O 11-0.5x A near-infrared luminescent material with high quantum efficiency, wherein 0.001≤x≤0.01.

[0026] Preferably, x=0.005.

[0027] Furthermore, the precursor of La is selected from one or more of La carbonate, La oxide, La oxalate and La nitrate; the precursor of Sc is selected from Sc2O3; the precursor of Nb is selected from Nb2O5; the precursor of Cr is selected from one or more of Cr carbonate, Cr oxide, Cr oxalate and Cr nitrate.

[0028] Furthermore, the nominal composition of the synthesis is La2Sc 2-x Cr x In the step of producing an intermediate of O6 (wherein 0.001≤x≤0.01), the reducing atmosphere is ammonia or a nitrogen-hydrogen mixed gas, the temperature of the high-temperature solid phase reaction is 1400-1600° C., and the time of the high-temperature solid phase reaction is between 4 and 10 hours;

[0029] Furthermore, a chemical formula is obtained which can be expressed as La2Nb 2-x Sc 2-x Cr 2x O 11-0.5x In the step of preparing a near-infrared luminescent material with high quantum efficiency (wherein 0.001≤x≤0.01), the temperature of the high-temperature solid-phase reaction is between 1500 and 1700° C., and the time of the high-temperature solid-phase reaction is between 4 and 10 hours.

[0030] Optionally, the purity of the La precursor, the Nb precursor, the Sc precursor and the Cr precursor is not less than 99.5%.

[0031] The present invention also provides a near-infrared light-emitting device, which comprises a light-emitting diode and a light-emitting material, wherein the light-emitting diode can emit light with a wavelength range of 380nm to 480nm, and the light-emitting material at least comprises a chemical formula which can be expressed as La2Nb 2-x Sc 2-x Cr 2x O 11-0.5x (where 0.001≤x≤0.01) high quantum efficiency near-infrared luminescent material.

[0032] Beneficial Effects

[0033] The present invention provides a near-infrared luminescent material with high quantum efficiency and its preparation technology and application. 2-x Sc 2-x Cr 2x O 11-0.5x The chemical formula of (wherein 0.001≤x≤0.01) represents the near-infrared luminescent material with high quantum efficiency. The light absorption range of the near-infrared luminescent material is 250nm~490nm; under the excitation of 450nm blue light, the near-infrared luminescent material can emit near-infrared light with a main peak between 1000nm~1020nm and a half-width of 210nm~240nm, and a quantum efficiency ≥90%. Compared with the prior art, the beneficial effects of the present invention are: (1). The luminescent material has a high tolerance to defects caused by charge imbalance; (2). The quantum efficiency of the obtained luminescent material is relatively high; (3). The emission spectrum of the luminescent material has a wide half-width and can absorb blue light, so that it can be used in high-power near-infrared devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the spectrum obtained in Comparative Example 1 of the present invention;

[0035] Figure 2 This is the spectrum obtained in Comparative Example 2 of the present invention;

[0036] Figure 3 This is the spectrum obtained in Comparative Example 3 of the present invention;

[0037] Figure 4 This is the spectrum obtained in Comparative Example 4 of the present invention;

[0038] Figure 5 This is the spectrum obtained in Comparative Example 5 of the present invention;

[0039] Figure 6 is the emission spectrum in Example 1 of the present invention;

[0040] Figure 7 is the emission spectrum in Example 5 of the present invention;

[0041] Figure 8 This is a spectrum diagram of the device obtained in Example 11 of the present invention.

[0042] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0043] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only used to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0044] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0045] The present application proposes a near-infrared luminescent material with high quantum efficiency, which can be represented by a general chemical formula:

[0046] LqCy 2-x Sc 2-x Cr 2x O 11-0.5x

[0047] Among them, 0.001≤x≤0.01.

[0048] In some embodiments provided by the present invention, x is preferably 0.001; in some embodiments provided by the present invention, x is preferably 0.002; in some embodiments provided by the present invention, x is preferably 0.003; in some embodiments provided by the present invention, x is preferably 0.004; in some embodiments provided by the present invention, x is preferably 0.005; in some embodiments provided by the present invention, x is preferably 0.006; in some embodiments provided by the present invention, x is preferably 0.007; in some embodiments provided by the present invention, x is preferably 0.008; in some embodiments provided by the present invention, x is preferably 0.009; in other embodiments provided by the present invention, x is preferably 0.01.

[0049] The present application also proposes a preparation technology for a near-infrared luminescent material with high quantum efficiency, the steps of which are as follows:

[0050] A) La precursor, Sc precursor and Cr precursor are mixed and subjected to high temperature solid phase reaction under reducing atmosphere to obtain a La2Sc 2-x Cr x Intermediates of O6, where 0.001≤x≤0.01;

[0051] B) Change the nominal composition to La2Sc 2-x Cr xThe intermediate of O6, Nb precursor and Cr precursor are mixed and reacted at high temperature in air atmosphere to obtain a chemical formula which can be expressed as La2Nb 2-x Sc 2-x Cr 2x O 11-0.5x A near-infrared luminescent material with high quantum efficiency, wherein 0.001≤x≤0.01.

[0052] In the above step A), the molar ratio of La, Sc and Cr in the La precursor, Sc precursor and Cr precursor is 2:(2-x):x, and the nominal composition of the intermediate is: La2Sc 2-x Cr x O6, where 0.001≤x≤0.01.

[0053] In the above step A), the La precursor can be a compound containing La well known in the art, without any special restrictions. In the present invention, the La precursor is preferably selected from one or more of La carbonate, La oxide, La oxalate and La nitrate, more preferably La oxide, i.e. La2O3; the Sc precursor is selected from Sc oxide, i.e. Sc2O3; the Cr precursor can be a compound containing Cr well known in the art, without any special restrictions. In the present invention, it is preferably one or more of Cr carbonate, Cr oxide, Cr oxalate and Cr nitrate, more preferably Cr oxide, i.e. Cr2O3.

[0054] In the above step B), the nominal composition is La2Sc 2-x Cr x The molar ratio of the intermediate of O6, the intermediate of Nb precursor and the intermediate of Cr precursor, Nb and Cr is 1:(2-x):x, wherein 0.001≤x≤0.01.

[0055] In the above step B), the precursor of Nb is selected from Nb oxide, i.e. Nb2O5; in the present invention, it is preferably one or more of Cr carbonate, Cr oxide, Cr oxalate and Cr nitrate, and more preferably Cr oxide, i.e. Cr2O3.

[0056] The purity of the La precursor, Nb precursor, Sc precursor and Cr precursor is not less than 99.5%. The higher the purity, the less impurities in the obtained luminescent material.

[0057] In the above step A), the temperature of the high temperature solid phase reaction is between 1400 and 1600° C., and the time of the high temperature solid phase reaction is between 4 and 10 hours under a reducing atmosphere.

[0058] In the above step B), the temperature of the high temperature solid phase reaction is between 1500 and 1700° C., and the time of the high temperature solid phase reaction is between 4 and 10 hours in an air atmosphere.

[0059] The temperature of the high-temperature solid phase in the above step A) is preferably 1400-1600°C, in a reducing atmosphere; in some embodiments provided by the present invention, the temperature of the high-temperature solid phase is preferably 1500°C.

[0060] The high temperature solid phase time in the above step A) is preferably 4 to 10 hours, more preferably 5 to 8 hours; in some embodiments provided by the present invention, the high temperature solid phase time is preferably 6 hours.

[0061] The temperature of the high-temperature solid phase in the above step B) is preferably 1400-1600°C in air atmosphere; in some embodiments provided by the present invention, the temperature of the high-temperature solid phase is preferably 1600°C.

[0062] The high temperature solid phase time in the above step B) is preferably 4 to 10 hours, more preferably 5 to 8 hours; in some embodiments provided by the present invention, the high temperature solid phase time is preferably 6 hours.

[0063] In the above step A), the reducing atmosphere may be a dry atmosphere well known to those skilled in the art without any particular limitation, and ammonia is preferred in the present invention.

[0064] The high-temperature solid phase reaction is preferably carried out in a high-temperature furnace; after the reaction is carried out in step A) and step B), the furnace is cooled to room temperature to obtain a near-infrared luminescent material with high quantum efficiency.

[0065] The embodiment of the present application uses a high-temperature solid-phase reaction to successfully prepare a near-infrared luminescent material with high quantum efficiency.

[0066] The near-infrared light-emitting device is composed of at least a light-emitting diode and a light-emitting material, and the light-emitting material at least includes a chemical formula represented by La2Nb 2-x Sc 2-x Cr 2x O 11-0.5x (wherein 0.001≤x≤0.01) a near-infrared luminescent material with high quantum efficiency, and an emission wavelength range of the light-emitting diode is 380nm to 480nm.

[0067] The raw materials used in the following comparative examples and embodiments are all commercially available.

[0068] Comparative Example 1

[0069] The raw materials are La2O3, Sc2O3 and Cr2O3. According to the target chemical formula La2Sc 1.995 Cr 0.005The above raw materials were weighed, ground and mixed, and then loaded into a crucible (the molar ratio of La to Sc to Cr was 2:1.995:0.005). After sintering at 1500℃ for 6h in a high-temperature furnace under air atmosphere, the mixture was cooled to room temperature with the furnace to obtain a nominal composition of La2Sc 1.995 Cr 0.005 O6 material.

[0070] The phase composition of the obtained material was measured by X-ray diffractometer, and no obvious impurity phase was found. It is obvious that the raw materials La2O3, Sc2O3 and Cr2O3 have fully reacted at this temperature. The obtained material showed a light green color. The luminescence performance of the obtained material was measured by fluorescence spectrometer, and it was found that under the excitation of 445nm (main peak position of absorption spectrum) blue light, the main peak of the emission spectrum of the material was located at 795nm, and the half-height width of the emission spectrum was 102nm, that is, the material is a luminescent material that can absorb blue light and emit near-infrared light, but the luminescence intensity of the material is low, such as Figure 1 The quantum efficiency of the material was measured using a quantum efficiency tester, and it was determined that the quantum efficiency of the material was 3.5%, which is very low (see Table 1 for details) and has no practical value.

[0071] That is, the material obtained in Comparative Example 1 is a luminescent material that can be excited by blue light to emit near-infrared light, but has no practical value.

[0072] Comparative Example 2

[0073] The raw materials are La2O3, Sc2O3 and Cr2O3. According to the target chemical formula La2Sc 1.995 Cr 0.005 The above raw materials were weighed, ground and mixed, and then loaded into a crucible (the molar ratio of La to Sc to Cr was 2:1.995:0.005). They were sintered at 1500℃ for 6h in a high-temperature furnace under an ammonia atmosphere and then cooled to room temperature to obtain a nominal composition of La2Sc 1.995 Cr 0.005 O6 material.

[0074] The phase composition of the obtained material was measured by X-ray diffractometer, and no obvious impurity phase was found. It is obvious that the raw materials La2O3, Sc2O3 and Cr2O3 have fully reacted at this temperature. The obtained material is light green. The luminescence performance of the obtained material was measured by fluorescence spectrometer, and it was found that under the excitation of 445nm (main peak position of absorption spectrum) blue light, the main peak of the emission spectrum of the material is located at 799nm, and the half-height width of the emission spectrum is 105nm, that is, the material is a luminescent material that can absorb blue light and emit near-infrared, and the luminescence intensity of the material is higher than that of comparative example 1, as shown in FIG. Figure 2 As shown. Obviously, the use of reducing atmosphere can promote Cr 3+The quantum efficiency of the material was measured using a quantum efficiency tester and was determined to be 10.9%, which is still relatively low (see Table 1 for details) and has no practical value.

[0075] That is, the material obtained in Comparative Example 2 is a luminescent material that can be excited by blue light to emit near-infrared light, but has no practical value.

[0076] Comparative Example 3

[0077] Follow the steps below to make it:

[0078] A) The raw materials are La2O3, Sc2O3 and Cr2O3, according to the target chemical formula La2Sc 1.995 Cr 0.005 The above raw materials (the molar ratio of La to Sc to Cr is 2:1.995:0.005) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1500℃ for 6h in a high-temperature furnace under air atmosphere, the mixture is cooled to room temperature with the furnace to obtain a nominal composition of La2Sc 1.995 Cr 0.005 Intermediate of O6.

[0079] B) Nominal composition is La2Sc 1.995 Cr 0.005 O6 intermediates and Nb2O5 and Cr2O3 as raw materials, according to La2Nb 1.995 Sc 1.995 Cr 0.01 O 10.9975 The above raw materials (the molar ratio of the intermediate to Nb and Cr is 1:1.995:0.005) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1600℃ for 6h in a high-temperature furnace under air atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Nb 1.995 Sc 1.995 Cr 0.01 O 10.9975 materials.

[0080] The phase composition of the obtained material was measured using an X-ray diffractometer, and no obvious Nb2O5 and Cr2O3 impurities were found. It is obvious that the intermediate and the Nb2O5 and Cr2O3 raw materials have fully reacted at this temperature. The obtained material exhibits a light purple pink color. The luminescence properties of the obtained material were measured using a fluorescence spectrometer, and it was found that under the excitation of 445nm (main peak position of the absorption spectrum) blue light, the main peak of the emission spectrum of the material was located at 798nm; the half-height width of the emission spectrum of the material was 212nm. That is, after the addition of Nb, the half-height width of the emission spectrum of the material increased significantly (compared with Comparative Examples 1 and 2), such as Figure 3As shown. That is, the material is a luminescent material that can absorb blue light and emit near-infrared light, and the half-width of the emission spectrum is wide. The quantum efficiency of the material was measured using a quantum efficiency tester and determined to be 11.6%, which is still relatively low (see Table 1 for details) and has no practical value. Although it is generally believed that due to the large difference in charge number, Cr 3+ It is difficult to replace Nb 5+ ; and even if the replacement is successful, due to the imbalance of charge number, Cr 3+ Replace Nb 5+ Defects will inevitably form after the sample is exposed, which will lead to a decrease in the luminescence intensity of the sample. Figure 3 It can be seen that the luminescence intensity of the sample (compared with Comparative Example 1 and Comparative Example 2) is higher.

[0081] That is, the material obtained in Comparative Example 3 is a luminescent material that can be excited by blue light to emit near-infrared light, but has no practical value.

[0082] Comparative Example 4

[0083] Follow the steps below to make it:

[0084] A) The raw materials are La2O3, Sc2O3 and Cr2O3, according to the target chemical formula La2Sc 1.995 Cr 0.005 The above raw materials (the molar ratio of La to Sc to Cr is 2:1.995:0.005) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1500℃ for 6h in a high-temperature furnace under an ammonia atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Sc 1.995 Cr 0.005 Intermediate of O6.

[0085] B) Nominal composition is La2Sc 1.995 Cr 0.005 O6 intermediates and Nb2O5 and Cr2O3 as raw materials, according to La2Nb 1.995 Sc 1.995 Cr 0.01 O 10.9975 The above raw materials (the molar ratio of the intermediate to Nb and Cr is 1:1.995:0.005) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1600℃ for 6h in a high-temperature furnace under an ammonia atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Nb 1.995 Sc 1.995 Cr 0.01 O 10.9975 materials.

[0086] The phase composition of the obtained material was measured by X-ray diffractometer, and no obvious Nb2O5 and Cr2O3 impurities were found. It is obvious that the intermediate and the Nb2O5 and Cr2O3 raw materials have fully reacted at this temperature. The obtained material is black-gray. The luminescence properties of the obtained material were measured by fluorescence spectrometer, and it was found that the material did not emit light under the excitation of any wavelength between 250 and 480 nm. Figure 4 As shown. It can be seen that the reducing atmosphere used in step B) of ratio 4 makes Cr 3+ Replace Nb 5+ The post-formation defects play a role, resulting in a decrease in the luminescence intensity of the sample (to no luminescence).

[0087] That is, the material obtained in Comparative Example 4 is not a luminescent material that can emit near-infrared light.

[0088] Comparative Example 5

[0089] Follow the steps below to make it:

[0090] A) The raw materials are La2O3, Sc2O3 and Cr2O3, according to the target chemical formula La2Sc 1.995 Cr 0.005 The above raw materials (the molar ratio of La to Sc to Cr is 2:1.995:0.005) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1500℃ for 6h in a high-temperature furnace under air atmosphere, the mixture is cooled to room temperature with the furnace to obtain a nominal composition of La2Sc 1.995 Cr 0.005 Intermediate of O6.

[0091] B) Nominal composition is La2Sc 1.995 Cr 0.005 O6 intermediates and Nb2O5 and Cr2O3 as raw materials, according to La2Nb 1.995 Sc 1.995 Cr 0.01 O 10.9975 The above raw materials (the molar ratio of the intermediate to Nb and Cr is 1:1.995:0.005) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1600℃ for 6h in a high-temperature furnace under an ammonia atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Nb 1.995 Sc 1.995 Cr 0.01 O 10.9975 materials.

[0092] The phase composition of the obtained material was measured by X-ray diffractometer, and no obvious Nb2O5 and Cr2O3 impurities were found. It is obvious that the intermediate and the Nb2O5 and Cr2O3 raw materials have fully reacted at this temperature. The obtained material is black-gray. The luminescence properties of the obtained material were measured by fluorescence spectrometer, and it was found that the material did not emit light under the excitation of any wavelength between 250 and 480 nm. Figure 5 As shown. It can be seen that the reducing atmosphere used in step B) of comparative example 5 makes Cr 3+ Replace Nb 5+ The post-formation defects play a role, resulting in a decrease in the luminescence intensity of the sample (to no luminescence).

[0093] That is, the material obtained in Comparative Example 5 is not a luminescent material that can emit near-infrared light.

[0094] Example 1

[0095] Follow the steps below to make it:

[0096] A) The raw materials are La2O3, Sc2O3 and Cr2O3, according to the target chemical formula La2Sc 1.999 Cr 0.001 The above raw materials (the molar ratio of La to Sc to Cr is 2:1.999:0.001) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1500℃ for 6h in a high-temperature furnace under an ammonia atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Sc 1.999 Cr 0.001 Intermediate of O6.

[0097] B) Nominal composition is La2Sc 1.999 Cr 0.001 O6 intermediates and Nb2O5 and Cr2O3 as raw materials, according to La2Nb 1.999 Sc 1.999 Cr 0.002 O 10.9995 The above raw materials (the molar ratio of the intermediate to Nb and Cr is 1:1.999:0.001) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1600℃ for 6h in a high-temperature furnace under air atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Nb 1.999 Sc 1.999 Cr 0.002 O 10.9995 materials.

[0098] The phase composition of the obtained material was measured using an X-ray diffractometer, and no obvious Nb2O5 and Cr2O3 impurities were found. It is obvious that the intermediate and the Nb2O5 and Cr2O3 raw materials have fully reacted at this temperature. The obtained material is purple-pink. The luminescence properties of the obtained material were measured using a fluorescence spectrometer, and it was found that under the excitation of 445nm (main peak position of the absorption spectrum) blue light, the main peak of the emission spectrum of the material is located at 1001nm; the half-height width of the emission spectrum of the material is 214nm. That is, after the addition of Nb, the half-height width of the emission spectrum of the material is significantly increased (compared with Comparative Examples 1 and 2), such as Figure 6 As shown. That is, the material is a luminescent material that can absorb blue light and emit near-infrared light, and the half-width of the emission spectrum is wide. The quantum efficiency of the material was measured using a quantum efficiency tester and determined to be 90.3%, which is high (see Table 1 for details) and has great practical value. Although it is generally believed that due to the large difference in charge number, Cr 3+ It is difficult to replace Nb 5+ ; and even if the replacement is successful, due to the imbalance of charge number, Cr 3+ Replace Nb 5+ Defects will inevitably form after the sample is exposed, which will lead to a decrease in the luminescence intensity of the sample. Figure 6 It can be seen that the luminescence intensity of the sample (compared with Comparative Example 1 and Comparative Example 2) is higher.

[0099] It can be seen that the material obtained in Example 1 is a luminescent material that can be excited by blue light to emit near-infrared light and has a high quantum efficiency, so that it can be used in high-power near-infrared devices.

[0100] Example 2

[0101] Follow the steps below to make it:

[0102] A) The raw materials are La2O3, Sc2O3 and Cr2O3, according to the target chemical formula La2Sc 1.998 Cr 0.002 The above raw materials (the molar ratio of La to Sc to Cr is 2:1.998:0.002) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1500℃ for 6h in a high-temperature furnace under an ammonia atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Sc 1.998 Cr 0.002 Intermediate of O6.

[0103] B) Nominal composition is La2Sc 1.998 Cr 0.002 O6 intermediates and Nb2O5 and Cr2O3 as raw materials, according to La2Nb 1.998 Sc 1.998 Cr 0.004 O 10.999The above raw materials (the molar ratio of the intermediate to Nb and Cr is 1:1.998:0.002) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1600℃ for 6h in a high-temperature furnace under air atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Nb 1.998 Sc 1.998 Cr 0.004 O 10.999 materials.

[0104] The phase composition of the obtained material was measured using an X-ray diffractometer, and no obvious Nb2O5 and Cr2O3 impurities were found. Obviously, at this temperature, the intermediate and the Nb2O5 and Cr2O3 raw materials have fully reacted. The obtained material is purple-pink. The luminescence properties of the obtained material were measured using a fluorescence spectrometer, and it was found that under the excitation of blue light at 445nm (main peak position of the absorption spectrum), the main peak of the emission spectrum of the material was located at 1003nm; the half-width of the emission spectrum of the material was 216nm. That is, after the addition of Nb, the half-width of the emission spectrum of the material increased significantly (compared with Comparative Examples 1 and 2). That is, the material is a luminescent material that can absorb blue light and emit near-infrared, and the half-width of the emission spectrum is wide. The quantum efficiency of the material was measured using a quantum efficiency tester, and it was determined that the quantum efficiency of the material was 91.6%, which is relatively high (see Table 1 for details), and is very practical. Although it is generally believed that due to the large difference in charge number, Cr 3+ It is difficult to replace Nb 5+ ; and even if the replacement is successful, due to the imbalance of charge number, Cr 3+ Replace Nb 5+ Defects will inevitably be formed, resulting in a decrease in the luminescence intensity of the sample. However, as can be seen from Table 1, the quantum efficiency of the sample obtained in Example 2 is higher (compared to Comparative Examples 1 and 2).

[0105] It can be seen that the material obtained in Example 2 is a luminescent material that can be excited by blue light to emit near-infrared light and has a high quantum efficiency, so that it can be used in high-power near-infrared devices.

[0106] Example 3

[0107] Follow the steps below to make it:

[0108] A) The raw materials are La2O3, Sc2O3 and Cr2O3, according to the target chemical formula La2Sc 1.997 Cr 0.003 The above raw materials (the molar ratio of La to Sc to Cr is 2:1.997:0.003) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1500℃ for 6h in a high-temperature furnace under an ammonia atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Sc 1.997 Cr 0.003Intermediate of O6.

[0109] B) Nominal composition is La2Sc 1.997 Cr 0.003 O6 intermediates and Nb2O5 and Cr2O3 as raw materials, according to La2Nb 1.997 Sc 1.997 Cr 0.006 O 10.9985 The above raw materials (the molar ratio of the intermediate to Nb and Cr is 1:1.997:0.003) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1600℃ for 6h in a high-temperature furnace under air atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Nb 1.997 Sc 1.997 Cr 0.006 O 10.9985 materials.

[0110] The phase composition of the obtained material was measured using an X-ray diffractometer, and no obvious Nb2O5 and Cr2O3 impurities were found. Obviously, at this temperature, the intermediate and the Nb2O5 and Cr2O3 raw materials have fully reacted. The obtained material is purple-pink. The luminescence properties of the obtained material were measured using a fluorescence spectrometer, and it was found that under the excitation of blue light at 445nm (main peak position of the absorption spectrum), the main peak of the emission spectrum of the material was located at 1006nm; the half-width of the emission spectrum of the material was 219nm. That is, after the addition of Nb, the half-width of the emission spectrum of the material increased significantly (compared with Comparative Examples 1 and 2). That is, the material is a luminescent material that can absorb blue light and emit near-infrared, and the half-width of the emission spectrum is wide. The quantum efficiency of the material was measured using a quantum efficiency tester, and it was determined that the quantum efficiency of the material was 92.1%, which is relatively high (see Table 1 for details), and is very practical. Although it is generally believed that due to the large difference in charge number, Cr 3+ It is difficult to replace Nb 5+ ; and even if the replacement is successful, due to the imbalance of charge number, Cr 3+ Replace Nb 5+ Defects will inevitably be formed, resulting in a decrease in the luminescence intensity of the sample. However, it can be seen from Table 1 that the quantum efficiency of the sample obtained in Example 3 (compared with Comparative Examples 1 and 2) is higher.

[0111] It can be seen that the material obtained in Example 3 is a luminescent material that can be excited by blue light to emit near-infrared light and has a high quantum efficiency, so it can be used in high-power near-infrared devices.

[0112] Example 4

[0113] Follow the steps below to make it:

[0114] A) The raw materials are La2O3, Sc2O3 and Cr2O3, according to the target chemical formula La2Sc 1.996 Cr 0.004 The above raw materials (the molar ratio of La to Sc to Cr is 2:1.996:0.004) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1500℃ for 6h in a high-temperature furnace under an ammonia atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Sc 1.996 Cr 0.004 Intermediate of O6.

[0115] B) Nominal composition is La2Sc 1.996 Cr 0.004 O6 intermediates and Nb2O5 and Cr2O3 as raw materials, according to La2Nb 1.996 Sc 1.996 Cr 0.008 O 10.998 The above raw materials (the molar ratio of the intermediate to Nb and Cr is 1:1.996:0.004) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1600℃ for 6h in a high-temperature furnace under air atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Nb 1.996 Sc 1.996 Cr 0.008 O 10.998 materials.

[0116] The phase composition of the obtained material was measured using an X-ray diffractometer, and no obvious Nb2O5 and Cr2O3 impurities were found. Obviously, at this temperature, the intermediate and the Nb2O5 and Cr2O3 raw materials have fully reacted. The obtained material is purple-pink. The luminescence properties of the obtained material were measured using a fluorescence spectrometer, and it was found that under the excitation of blue light at 445nm (main peak position of the absorption spectrum), the main peak of the emission spectrum of the material was located at 1010nm; the half-width of the emission spectrum of the material was 225nm. That is, after the addition of Nb, the half-width of the emission spectrum of the material increased significantly (compared with Comparative Examples 1 and 2). That is, the material is a luminescent material that can absorb blue light and emit near-infrared, and the half-width of the emission spectrum is wide. The quantum efficiency of the material was measured using a quantum efficiency tester, and it was determined that the quantum efficiency of the material was 92.5%, which is relatively high (see Table 1 for details), and is very practical. Although it is generally believed that due to the large difference in charge number, Cr 3+ It is difficult to replace Nb 5+ ; and even if the replacement is successful, due to the imbalance of charge number, Cr 3+ Replace Nb 5+ Defects will inevitably be formed, resulting in a decrease in the luminescence intensity of the sample. However, it can be seen from Table 1 that the quantum efficiency of the sample obtained in Example 4 is higher (compared to Comparative Examples 1 and 2).

[0117] It can be seen that the material obtained in Example 4 is a luminescent material that can be excited by blue light to emit near-infrared light and has a high quantum efficiency, so it can be used in high-power near-infrared devices.

[0118] Example 5

[0119] Follow the steps below to make it:

[0120] A) The raw materials are La2O3, Sc2O3 and Cr2O3, according to the target chemical formula La2Sc 1.995 Cr 0.005 The above raw materials (the molar ratio of La to Sc to Cr is 2:1.995:0.005) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1500℃ for 6h in a high-temperature furnace under an ammonia atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Sc 1.995 Cr 0.005 Intermediate of O6.

[0121] B) Nominal composition is La2Sc 1.995 Cr 0.005 O6 intermediates and Nb2O5 and Cr2O3 as raw materials, according to La2Nb 1.995 Sc 1.995 Cr 0.01 O 10.9975 The above raw materials (the molar ratio of the intermediate to Nb and Cr is 1:1.995:0.005) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1600℃ for 6h in a high-temperature furnace under air atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Nb 1.995 Sc 1.995 Cr 0.01 O 10.9975 materials.

[0122] The phase composition of the obtained material was measured using an X-ray diffractometer, and no obvious Nb2O5 and Cr2O3 impurities were found. It is obvious that the intermediate and the Nb2O5 and Cr2O3 raw materials have fully reacted at this temperature. The obtained material is purple-pink. The luminescence properties of the obtained material were measured using a fluorescence spectrometer, and it was found that under the excitation of 445nm (main peak position of the absorption spectrum) blue light, the main peak of the emission spectrum of the material is located at 1012nm; the half-height width of the emission spectrum of the material is 228nm. That is, after the addition of Nb, the half-height width of the emission spectrum of the material is significantly increased (compared with Comparative Examples 1 and 2), such as Figure 7As shown. That is, the material is a luminescent material that can absorb blue light and emit near-infrared light, and the half-width of the emission spectrum is wide. The quantum efficiency of the material was measured using a quantum efficiency tester and determined to be 93.3%, which is high (see Table 1 for details) and has great practical value. Although it is generally believed that due to the large difference in charge number, Cr 3+ It is difficult to replace Nb 5+ ; and even if the replacement is successful, due to the imbalance of charge number, Cr 3+ Replace Nb 5+ Defects will inevitably form after the sample is exposed, which will lead to a decrease in the luminescence intensity of the sample. Figure 7 It can be seen that the luminescence intensity of the sample obtained in Example 5 is higher (compared with Comparative Examples 1 and 2).

[0123] It can be seen that the material obtained in Example 5 is a luminescent material that can be excited by blue light to emit near-infrared light and has a high quantum efficiency, so it can be used in high-power near-infrared devices.

[0124] Example 6

[0125] Follow the steps below to make it:

[0126] A) The raw materials are La2O3, Sc2O3 and Cr2O3, according to the target chemical formula La2Sc 1.994 Cr 0.006 The above raw materials (the molar ratio of La to Sc to Cr is 2:1.994:0.006) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1500℃ for 6h in a high-temperature furnace under an ammonia atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Sc 1.994 Cr 0.006 Intermediate of O6.

[0127] B) Nominal composition is La2Sc 1.994 Cr 0.006 O6 intermediates and Nb2O5 and Cr2O3 as raw materials, according to La2Nb 1.994 Sc 1.994 Cr 0.012 O 10.997 The above raw materials (the molar ratio of the intermediate to Nb and Cr is 1:1.994:0.006) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1600℃ for 6h in a high-temperature furnace under air atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Nb 1.994 Sc 1.994 Cr 0.012 O 10.997 materials.

[0128] The phase composition of the obtained material was measured using an X-ray diffractometer, and no obvious Nb2O5 and Cr2O3 impurities were found. Obviously, at this temperature, the intermediate and the Nb2O5 and Cr2O3 raw materials have fully reacted. The obtained material is purple-pink. The luminescence properties of the obtained material were measured using a fluorescence spectrometer, and it was found that under the excitation of blue light at 445nm (main peak position of the absorption spectrum), the main peak of the emission spectrum of the material was located at 1014nm; the half-width of the emission spectrum of the material was 230nm. That is, after the addition of Nb, the half-width of the emission spectrum of the material increased significantly (compared with Comparative Examples 1 and 2). That is, the material is a luminescent material that can absorb blue light and emit near-infrared, and the half-width of the emission spectrum is wide. The quantum efficiency of the material was measured using a quantum efficiency tester, and it was determined that the quantum efficiency of the material was 93.2%, which is relatively high (see Table 1 for details), and is very practical. Although it is generally believed that due to the large difference in charge number, Cr 3+ It is difficult to replace Nb 5+ ; and even if the replacement is successful, due to the imbalance of charge number, Cr 3+ Replace Nb 5+ Defects will inevitably be formed, resulting in a decrease in the luminescence intensity of the sample. However, it can be seen from Table 1 that the quantum efficiency of the sample obtained in Example 6 is higher (compared to Comparative Examples 1 and 2).

[0129] It can be seen that the material obtained in Example 6 is a luminescent material that can be excited by blue light to emit near-infrared light and has a high quantum efficiency, so it can be used in high-power near-infrared devices.

[0130] Example 7

[0131] Follow the steps below to make it:

[0132] A) The raw materials are La2O3, Sc2O3 and Cr2O3, according to the target chemical formula La2Sc 1.993 Cr 0.007 The above raw materials (the molar ratio of La to Sc to Cr is 2:1.993:0.007) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1500℃ for 6h in a high-temperature furnace under an ammonia atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Sc 1.993 Cr 0.007 Intermediate of O6.

[0133] B) Nominal composition is La2Sc 1.993 Cr 0.007 O6 intermediates and Nb2O5 and Cr2O3 as raw materials, according to La2Nb 1.993 Sc 1.993 Cr 0.014 O 10.9965The above raw materials (the molar ratio of the intermediate to Nb and Cr is 1:1.993:0.007) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1600℃ for 6h in a high-temperature furnace under air atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Nb 1.993 Sc 1.993 Cr 0.014 O 10.9965 materials.

[0134] The phase composition of the obtained material was measured using an X-ray diffractometer, and no obvious Nb2O5 and Cr2O3 impurities were found. Obviously, at this temperature, the intermediate and the Nb2O5 and Cr2O3 raw materials have fully reacted. The obtained material is purple-pink. The luminescence properties of the obtained material were measured using a fluorescence spectrometer, and it was found that under the excitation of blue light at 445nm (main peak position of the absorption spectrum), the main peak of the emission spectrum of the material was located at 1015nm; the half-width of the emission spectrum of the material was 233nm. That is, after the addition of Nb, the half-width of the emission spectrum of the material increased significantly (compared with Comparative Examples 1 and 2). That is, the material is a luminescent material that can absorb blue light and emit near-infrared, and the half-width of the emission spectrum is wide. The quantum efficiency of the material was measured using a quantum efficiency tester, and it was determined that the quantum efficiency of the material was 92.6%, which is relatively high (see Table 1 for details), and is very practical. Although it is generally believed that due to the large difference in charge number, Cr 3+ It is difficult to replace Nb 5+ ; and even if the replacement is successful, due to the imbalance of charge number, Cr 3+ Replace Nb 5+ Defects will inevitably be formed, resulting in a decrease in the luminescence intensity of the sample. However, it can be seen from Table 1 that the quantum efficiency of the sample obtained in Example 7 is higher (compared to Comparative Examples 1 and 2).

[0135] It can be seen that the material obtained in Example 7 is a luminescent material that can be excited by blue light to emit near-infrared light and has a high quantum efficiency, so it can be used in high-power near-infrared devices.

[0136] Example 8

[0137] Follow the steps below to make it:

[0138] A) The raw materials are La2O3, Sc2O3 and Cr2O3, according to the target chemical formula La2Sc 1.992 Cr 0.008 The above raw materials (the molar ratio of La to Sc to Cr is 2:1.992:0.008) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1500℃ for 6h in a high-temperature furnace under an ammonia atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Sc 1.992 Cr 0.008Intermediate of O6.

[0139] B) Nominal composition is La2Sc 1.992 Cr 0.008 O6 intermediates and Nb2O5 and Cr2O3 as raw materials, according to La2Nb 1.992 Sc 1.992 Cr 0.016 O 10.996 The above raw materials (the molar ratio of the intermediate to Nb and Cr is 1:1.992:0.008) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1600℃ for 6h in a high-temperature furnace under air atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Nb 1.992 Sc 1.992 Cr 0.016 O 10.996 materials.

[0140] The phase composition of the obtained material was measured using an X-ray diffractometer, and no obvious Nb2O5 and Cr2O3 impurities were found. Obviously, at this temperature, the intermediate and the Nb2O5 and Cr2O3 raw materials have fully reacted. The obtained material is purple-pink. The luminescence properties of the obtained material were measured using a fluorescence spectrometer, and it was found that under the excitation of blue light at 445nm (main peak position of the absorption spectrum), the main peak of the emission spectrum of the material was located at 1016nm; the half-width of the emission spectrum of the material was 234nm. That is, after the addition of Nb, the half-width of the emission spectrum of the material increased significantly (compared with Comparative Examples 1 and 2). That is, the material is a luminescent material that can absorb blue light and emit near-infrared, and the half-width of the emission spectrum is wide. The quantum efficiency of the material was measured using a quantum efficiency tester, and it was determined that the quantum efficiency of the material was 90.8%, which is relatively high (see Table 1 for details), and is very practical. Although it is generally believed that due to the large difference in charge number, Cr 3+ It is difficult to replace Nb 5+ ; and even if the replacement is successful, due to the imbalance of charge number, Cr 3+ Replace Nb 5+ Defects will inevitably be formed, resulting in a decrease in the luminescence intensity of the sample. However, it can be seen from Table 1 that the quantum efficiency of the sample obtained in Example 8 is higher (compared to Comparative Examples 1 and 2).

[0141] It can be seen that the material obtained in Example 8 is a luminescent material that can be excited by blue light to emit near-infrared light and has a high quantum efficiency, so it can be used in high-power near-infrared devices.

[0142] Example 9

[0143] Follow the steps below to make it:

[0144] A) The raw materials are La2O3, Sc2O3 and Cr2O3, according to the target chemical formula La2Sc 1.991 Cr 0.009 The above raw materials (the molar ratio of La to Sc to Cr is 2:1.991:0.009) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1500℃ for 6h in a high-temperature furnace under an ammonia atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Sc 1.991 Cr 0.009 Intermediate of O6.

[0145] B) Nominal composition is La2Sc 1.991 Cr 0.009 O6 intermediates and Nb2O5 and Cr2O3 as raw materials, according to La2Nb 1.991 Sc 1.991 Cr 0.018 O 10.9955 The above raw materials (the molar ratio of the intermediate to Nb and Cr is 1:1.991:0.009) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1600℃ for 6h in a high-temperature furnace under air atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Nb 1.991 Sc 1.991 Cr 0.018 O 10.9955 materials.

[0146] The phase composition of the obtained material was measured using an X-ray diffractometer, and no obvious Nb2O5 and Cr2O3 impurities were found. Obviously, at this temperature, the intermediate and the Nb2O5 and Cr2O3 raw materials have fully reacted. The obtained material is purple-pink. The luminescence properties of the obtained material were measured using a fluorescence spectrometer, and it was found that under the excitation of blue light at 445nm (main peak position of the absorption spectrum), the main peak of the emission spectrum of the material was located at 1018nm; the half-width of the emission spectrum of the material was 237nm. That is, after the addition of Nb, the half-width of the emission spectrum of the material increased significantly (compared with Comparative Examples 1 and 2). That is, the material is a luminescent material that can absorb blue light and emit near-infrared, and the half-width of the emission spectrum is wide. The quantum efficiency of the material was measured using a quantum efficiency tester, and it was determined that the quantum efficiency of the material was 90.1%, which is relatively high (see Table 1 for details), and is very practical. Although it is generally believed that due to the large difference in charge number, Cr 3+ It is difficult to replace Nb 5+ ; and even if the replacement is successful, due to the imbalance of charge number, Cr 3+ Replace Nb 5+ Defects will inevitably be formed, resulting in a decrease in the luminescence intensity of the sample. However, it can be seen from Table 1 that the quantum efficiency of the sample obtained in Example 9 is higher (compared to Comparative Examples 1 and 2).

[0147] It can be seen that the material obtained in Example 9 is a luminescent material that can be excited by blue light to emit near-infrared light and has a high quantum efficiency, so it can be used in high-power near-infrared devices.

[0148] Example 10

[0149] Follow the steps below to make it:

[0150] A) The raw materials are La2O3, Sc2O3 and Cr2O3, according to the target chemical formula La2Sc 1.99 Cr 0.01 The above raw materials (the molar ratio of La to Sc to Cr is 2:1.99:0.01) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1500℃ for 6h in a high-temperature furnace under an ammonia atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Sc 1.99 Cr 0.01 Intermediate of O6.

[0151] B) Nominal composition is La2Sc 1.99 Cr 0.01 O6 intermediates and Nb2O5 and Cr2O3 as raw materials, according to La2Nb 1.99 Sc 1.99 Cr 0.02 O 10.995 The above raw materials (the molar ratio of intermediate, Nb and Cr is 1:1.99:0.01) are weighed, ground and mixed, and then loaded into a crucible. After sintering at 1600℃ for 6h in a high-temperature furnace under air atmosphere, the furnace is cooled to room temperature to obtain a nominal composition of La2Nb 1.99 Sc 1.99 Cr 0.02 O 10.995 materials.

[0152] The phase composition of the obtained material was measured using an X-ray diffractometer, and no obvious Nb2O5 and Cr2O3 impurities were found. Obviously, at this temperature, the intermediate and the Nb2O5 and Cr2O3 raw materials have fully reacted. The obtained material is purple-pink. The luminescence properties of the obtained material were measured using a fluorescence spectrometer, and it was found that under the excitation of blue light at 445nm (main peak position of the absorption spectrum), the main peak of the emission spectrum of the material was located at 1019nm; the half-width of the emission spectrum of the material was 239nm. That is, after the addition of Nb, the half-width of the emission spectrum of the material increased significantly (compared with Comparative Examples 1 and 2). That is, the material is a luminescent material that can absorb blue light and emit near-infrared, and the half-width of the emission spectrum is wide. The quantum efficiency of the material was measured using a quantum efficiency tester, and it was determined that the quantum efficiency of the material was 91.6%, which is relatively high (see Table 1 for details), and is very practical. Although it is generally believed that due to the large difference in charge number, Cr3+ It is difficult to replace Nb 5+ ; and even if the replacement is successful, due to the imbalance of charge number, Cr 3+ Replace Nb 5+ Defects will inevitably be formed, resulting in a decrease in the luminescence intensity of the sample. However, it can be seen from Table 1 that the quantum efficiency of the sample obtained in Example 10 (compared with Comparative Examples 1 and 2) is higher.

[0153] It can be seen that the material obtained in Example 10 is a luminescent material that can be excited by blue light to emit near-infrared light and has a high quantum efficiency, so it can be used in high-power near-infrared devices.

[0154] Embodiment 11

[0155] The luminescent material obtained in Example 5 is packaged with a blue light LED having an emission wavelength of 450 nm. Figure 8 The spectrum of the device obtained in Example 11 is given. It is obvious that a near-infrared device can be prepared after packaging Example 5 and a blue light LED.

[0156] Table 1 Luminescence performance data of near-infrared luminescent materials with high quantum efficiency

[0157] Serial number Emission spectrum main peak position (nm) Half-width (nm) Quantum efficiency (%) Comparative Example 1 795 102 3.5 Comparative Example 2 799 105 10.9 Comparative Example 3 798 212 11.6 Comparative Example 4 / / / Comparative Example 5 / / / Example 1 1001 214 90.3 Example 2 1003 216 91.6 Example 3 1006 219 92.1 Example 4 1010 225 92.5 Example 5 1012 228 93.3 Example 6 1014 230 93.2 Example 7 1015 233 92.6 Example 8 1016 234 90.8 Example 9 1018 237 90.1 Example 10 1019 239 91.6

[0158] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0159] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0160] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A near-infrared luminescent material with high quantum efficiency, characterized in that: The chemical formula of the near-infrared luminescent material with high quantum efficiency can be expressed as: La2Nb 2-x Sc 2-x Cr 2x O 11-0.5x , wherein 0.001≤x≤0.01; the near-infrared luminescent material with high quantum efficiency can absorb light in the range of 250nm to 490nm; under the excitation of 450nm blue light, the main peak of the emission spectrum of the near-infrared luminescent material with high quantum efficiency is located between 1000nm and 1020nm, the half-width of the emission spectrum is 210nm to 240nm, and the quantum efficiency is ≥90%.

2. The near-infrared luminescent material with high quantum efficiency according to claim 1, characterized in that: Said x=0.

005.

3. A near-infrared luminescent material with high quantum efficiency according to any one of claims 1 to 2, wherein the preparation method thereof comprises the following steps: A) La precursor, Sc precursor and Cr precursor are mixed and subjected to high temperature solid phase reaction under reducing atmosphere to obtain a La2Sc 2-x Cr x O6 intermediates, among which 0.001≤x≤0.01； B) Change the nominal composition to La2Sc 2-x Cr x The intermediate of O6, Nb precursor and Cr precursor are mixed and reacted at high temperature in air atmosphere to obtain a chemical formula which can be expressed as La2Nb 2-x Sc 2-x Cr 2x O 11-0.5x A near-infrared luminescent material with high quantum efficiency, wherein 0.001≤x≤0.

01.

4. The method for preparing a near-infrared luminescent material with high quantum efficiency as claimed in claim 3, characterized in that: In the step A), the molar ratio of La, Sc and Cr in the La precursor, Sc precursor and Cr precursor is 2:(2-x):x, and the nominal composition of the intermediate is: La2Sc 2-x Cr x O6, wherein 0.001≤x≤0.01; in the step B), the molar ratio of the intermediate, Nb and Cr in the intermediate, Nb precursor and Cr precursor is 1:(2-x):x, wherein 0.001≤x≤0.

01.

5. The method for preparing a near-infrared luminescent material with high quantum efficiency as claimed in claim 3, characterized in that: The purity of the La precursor, the Nb precursor, the Sc precursor and the Cr precursor is not less than 99.5%.

6. The method for preparing a near-infrared luminescent material with high quantum efficiency as claimed in claim 3, characterized in that: In the step A), the reducing atmosphere is ammonia or a nitrogen-hydrogen mixed gas, the temperature of the high-temperature solid phase reaction is 1400-1600° C., and the time of the high-temperature solid phase reaction is between 4 and 10 hours; in the step B), under an air atmosphere, the temperature of the high-temperature solid phase reaction is between 1500-1700° C., and the time of the high-temperature solid phase reaction is between 4 and 10 hours.

7. The method for preparing a near-infrared luminescent material with high quantum efficiency as claimed in claim 3, characterized in that: In the step A), the precursor of La is selected from one or more of La carbonate, La oxide, La oxalate and La nitrate; the precursor of Sc is selected from Sc oxide, i.e. Sc2O3; the body of Cr is selected from one or more of Cr carbonate, Cr oxide, Cr oxalate and Cr nitrate. In the step B), the precursor of Nb is selected from Nb oxide, i.e. Nb2O5; the body of Cr is selected from one or more of Cr carbonate, Cr oxide, Cr oxalate and Cr nitrate.

8. A near-infrared light-emitting device, comprising: A light emitting diode and a light emitting material, the light emitting material comprising the chemical formula as described in any one of claims 1 and / or 2, which can be represented by La2Nb 2-x Sc 2-x Cr 2-x O 11-0.5x (in, 0.001≤x≤0.01) with high quantum efficiency near-infrared luminescent materials.

9. The near-infrared light-emitting device according to claim 8, wherein: The luminescent material also includes a material different from the general chemical formula La2Nb 2-x Sc 2-x Cr 2-x O 11-0.5x (in, 0.001≤x≤0.01) of an inorganic fluorescent material or an organic fluorescent material with high quantum efficiency near-infrared luminescent material.

10. The near-infrared light emitting device according to claim 8, characterized in that: The emission wavelength range of the light emitting diode is 380nm-490nm.

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