Near-infrared luminescent material as well as preparation method and application thereof

Abstract

The invention discloses a near-infrared luminescent material as well as a preparation method and application thereof, and belongs to the field of near-infrared luminescent materials. According to the method, an Al source, H3BO3 and other raw materials are added into a SiO2 matrix to inhibit Sm < 3 + > luminescence, so that Sm < 2 + > near-infrared luminescence is realized, and finally, the near-infrared luminescent material with the Sm < 2 + > luminescence characteristic is obtained. According to the process, orange luminescence of Sm < 3 + > can be inhibited, the color purity is improved, and the luminescence property of Sm < 2 + > can be greatly improved. The chemical composition of the near-infrared luminescent material disclosed by the invention is Si < 1-x > Al < x > B < y > N < z > O < 2-z >: S < mm >, Ln < n >, ln is one or more elements of Yb, Eu, Gd and Ce; 0 < = x < = 0.1, 0 < = y < = 0.5, 0 < = z < = 0.5, 0 < = m < = 0.1, and 0 < = n < = 0.1. The material can be excited by light within the wavelength range of 300-600 nm, so that narrow-band near-infrared light of 683 nm is emitted, and therefore, the luminescent material can convert ultraviolet light, purple blue light and green light into near-infrared light. The near-infrared luminescent material disclosed by the invention is simple and convenient in synthesis method, pollution-free, stable in chemical performance and wide in application field, and can be produced on a large scale.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of inorganic luminescent materials, and realizes near-infrared luminescent materials through gap occupation and a preparation method thereof. BACKGROUND

[0002] In recent years, inorganic luminescent materials have been widely used in many technical fields such as LEDs due to their adjustable emission wavelength, simple synthesis method and excellent stability. In particular, near-infrared luminescent materials with an emission wavelength beyond 650 nm show important application potential in biomedical imaging, night vision technology, food detection, temperature sensing and other aspects [Ref. Non-patent document 1].

[0003] Cr 3+ Doped aluminate systems usually emit wavelengths in the range of 750-1100 nm, which perform well in near-infrared fluorescent conversion devices pc-LEDs, but their quantum efficiency and electro-optical conversion efficiency still need to be improved [Ref. Non-patent document 2]. Therefore, efforts are being made to explore and develop new luminescent centers to expand the diversity of near-infrared luminescent materials and meet the growing application needs in different technical fields. For upconversion systems (such as Er 3+ , Yb 3+ ), their upconversion efficiency is usually low because of the involvement of multi-photon processes and large energy loss. Although their preparation method is reproducible, high-efficiency upconversion luminescence usually requires high excitation power, which largely limits its application in some practical scenarios. Therefore, exploring new near-infrared luminescent centers is of great significance for the development of near-infrared luminescent materials. Sm 2+ has similar f-d transition absorption properties to Eu 2+ , but its emission will exhibit broadband (d-f) or linear (f-f) near-infrared emission due to different environments. It is a great challenge to obtain Sm 2+ host materials with excellent performance and stability. Sm 2+ is unstable and its near-infrared emission is sensitive to the crystal field environment, which restricts the development of near-infrared fluorescent powders.

[0004] For luminescent centers with d-f transition characteristics, the presence of high-valence states usually reduces the luminescent efficiency of the luminescent material, such as the presence of Eu 3+ and Yb 3+ , which usually suppresses the luminescent intensity of Eu 2+ and Yb 2+ , respectively [Ref. Non-patent document 3]. Therefore, reducing the content of high-valence luminescent centers plays an important role in improving the performance of luminescent materials.

[0005] Non-patent literature 1: Liu X, Aidilibike T, Guo J, et al. Upconversionluminescence of Sm 2+ ions[J]. RSC Advance, 2017, 7(23), 14010-14014. Non-patent literature 2: Wei S, Lyu Z, Sun D, ​​et al. A NIR phosphor with ultra-broadband emission enabled by dual energy transfer within two Cr 3+ emitters and Cr 3+ → Yb 3+ . Journal of Materials Chemistry C: Materials, 2024, 12(14):4077-4985. Non-patent literature 3: Li S, Wang L, Tang D, et al. Achieving high quantum efficiency narrow-band β-Sialon:Eu 2+ phosphors for high-brightness LCDbacklights by reducing the Eu 3+ luminescence killer. Chemistry of Materials C, 2018, 30(2):494-505. Summary of the Invention

[0006] Based on the above background, the present invention provides a novel Sm 2+ Near-infrared materials that exhibit near-infrared emission by occupying lattice channels are further optimized by introducing Al sources and H3BO3 to improve their luminescence intensity and their ability to reduce Sm. 3+ The degree of emission is significantly improved. Such unique luminescence behavior plays an important role and has promising applications in enriching the variety of near-infrared luminescent materials.

[0007] The material has a simple and efficient synthesis process, making it easy to industrialize and apply to a wide range of fields such as plant growth lighting, white LEDs, bio-imaging, and temperature sensors.

[0008] This invention is the result of a series of studies based on the above understanding, and thus successfully provides a near-infrared luminescent material. Its structure is shown in formula (I): A near-infrared luminescent material, as shown in formula (I): Si 1-x Al x B y N z O 2-z :Sm m ,Ln n (I); Where Ln is one or more elements of Yb, Eu, Gd, Ce; 0≤ x≤0.1, 0≤y≤0.5, 0≤ z≤0.5, 0≤m≤0.1, 0≤n≤0.1.

[0009] The present invention also discloses a method for preparing near-infrared phosphor, which involves mixing Sm precursor, Ln precursor, Al precursor, Si precursor and flux, grinding thoroughly to obtain a mixture and then subjecting it to a high-temperature solid-state reaction to obtain a near-infrared luminescent material. The molar ratios of each element in the Sm precursor, Ln precursor, Al precursor, Si precursor, and flux are as follows: The molar ratio of Si, Al, flux, Sm, and Ln is 1:x:y:m:n; 0≤x≤0.1, 0≤y≤0.5, 0≤m≤0.1, 0≤n≤0.1. The co-solvent includes H3BO3, and the amount used is 1-8% of the total mass of the raw materials.

[0010] Preferably, the purity of the Sm precursor, Ln precursor, Al precursor, Si precursor, and flux is not less than 99.5%.

[0011] Preferably, Sm precursor, Ln precursor, Al precursor, Si precursor and flux are mixed in a certain proportion and then reacted at high temperature in a reducing atmosphere. The final product is obtained by grinding after cooling to room temperature.

[0012] Preferably, the Sm precursor is one or more of the following: Sm carbonate, Sm oxide, Sm sulfide, Sm halide, Sm boride, Sm oxalate, and Sm nitrate. The Ln precursor is one or more of the following: Ln carbonate, Ln oxide, Ln sulfide, Ln chloride, Ln oxalate, and Ln nitrate. The Al precursor is one or more of Al oxides, Al nitrides, Al chlorides, Al nitrates, and Al carbonates; The Si precursor is one or more of Si oxides and Si nitrides.

[0013] Preferably, the reducing atmosphere is one of nitrogen, argon, argon-hydrogen, or a nitrogen-hydrogen mixture.

[0014] Preferably, the high-temperature sintering temperature is 1200~1500℃; the high-temperature sintering time is 1~6h.

[0015] This invention also discloses the application of a near-infrared luminescent material in bioimaging, plant growth lighting, high color rendering index white LEDs, and solar cells.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a method that can make SiO2:Sm 2+ Near-infrared luminescent materials with significantly enhanced luminescence intensity, their preparation methods, and applications can be discussed. The luminescence performance can be greatly improved by introducing an Al source (such as Al₂O₃ or AlN) and a flux containing H₃BO₃. Specifically, this method involves adding Al sources and H₃BO₃ to a SiO₂ matrix to suppress Sm⁻. 3+ The light emission of Sm 2+ Near-infrared emission ultimately yields only Sm 2+ Near-infrared luminescent materials with luminescent properties. This process can not only suppress Sm 3+ The orange glow enhances color purity and can also significantly improve Sm. 2+ Luminescent properties. Attached Figure Description

[0017] Figure 1 The X-ray diffraction patterns of the near-infrared luminescent materials obtained in Examples 1-4 of this invention are shown.

[0018] Figure 2 This is the normalized emission spectrum of the near-infrared luminescent material obtained in Example 1 of the present invention under 365nm excitation.

[0019] Figure 3 The normalized emission spectrum of the near-infrared luminescent material obtained in Example 4 of this invention under excitation at 326 nm and the normalized excitation spectrum monitored at 683 nm are shown.

[0020] Figure 4 This is the normalized emission intensity map measured at different temperatures in Example 4.

[0021] Figure 5 These are emission intensity diagrams for Examples 1-4.

[0022] Figure 6 These are the normalized emission spectra of Examples 1-4.

[0023] Figure 7 Sm is from Examples 1-4 2+ Comparison of luminous intensity. Detailed Implementation

[0024] The technical solutions of the present invention will be described in detail below with reference to the embodiments of the present invention. However, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] Example 1 According to the molar ratio of SiO2 (analytical grade) and Sm2O3 (analytical grade) of 1:0.005, the above raw materials were ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, in a H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100 mL / min), the mixture was first calcined at 450℃ for 1 hour, and then sintered at 1500℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0026] X-ray diffraction tests were performed on the material using an X-ray diffractometer, and no significant difference was found compared to the standard card PDF#39-1425. (See...) Figure 1 ) The optical properties of the near-infrared luminescent material obtained in Example 1 were analyzed using fluorescence spectroscopy. A narrow-band emission peak at 689 nm was observed under 365 nm ultraviolet light excitation (see [reference]). Figure 2 However, the peak intensity is weak, and Sm is present. 3+ luminescence (Sm) 3+ It is not the target emission color; it is orange light emission, which will affect Sm 2+ (luminous intensity).

[0027] Example 2 According to the molar ratio of SiO2 (analytical grade), Sm2O3 (analytical grade), and H3BO3 (analytical grade) of 1:0.005:0.03, the above raw materials were taken separately, ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, in an H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100 mL / min), the mixture was first calcined at 450℃ for 1 hour, and then sintered at 1500℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0028] X-ray diffraction tests were performed on the material using an X-ray diffractometer, and no significant difference was found compared to the standard card PDF#39-1425 (see...). Figure 1 ).

[0029] The fluorescent material obtained in Example 2 was analyzed using a fluorescence spectrometer. Under 365 nm ultraviolet light excitation, its emission spectrum showed an increase in intensity of the narrow-band emission peak at 685 nm compared to Example 1 (see [link to sample image]). Figure 5 , Figure 6 and Figure 7 This indicates that adding flux H3BO3 can improve luminescence performance.

[0030] Example 3 According to the molar ratio of SiO2 (analytical grade), Al2O3 (analytical grade), and Sm2O3 (analytical grade) of 0.94:0.06:0.005, the raw materials were taken separately and thoroughly ground and mixed in an agate mortar. After drying, they were placed into an Al2O3 crucible and calcined at 450℃ for 1 hour in a high-temperature furnace with a H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100 mL / min). Then, they were sintered at 1500℃ for 6 hours. After the reaction was completed, the furnace was cooled to room temperature and ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0031] X-ray diffraction tests were performed on the material using an X-ray diffractometer, and no significant difference was found compared to the standard card PDF#39-1425 (see...). Figure 1 ).

[0032] The luminescent material obtained in Example 3 was analyzed using fluorescence spectroscopy. The emission peak under 365 nm ultraviolet light excitation was located at 683 nm, showing an increase in intensity compared to the samples in Examples 1 and 2. This indicates that the addition of Al₂O₃ can improve the luminescent performance, and the luminescent material can be excited by ultraviolet light to emit red light (see...). Figure 5 , Figure 6 and Figure 7 ).

[0033] Example 4 According to the molar ratio of SiO2 (analytical grade), Al2O3 (analytical grade), Sm2O3 (analytical grade), and H3BO3 (analytical grade) of 0.94:0.06:0.005:0.03, the raw materials were taken separately and thoroughly ground and mixed in an agate mortar. After drying, they were placed into an Al2O3 crucible and calcined at 450℃ for 1 hour in a high-temperature furnace in an H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100mL / min). Then, they were sintered at 1500℃ for 6 hours. After the reaction was completed, the furnace was cooled to room temperature and ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0034] X-ray diffraction tests were performed on the material using an X-ray diffractometer, and no significant difference was found compared to the standard card PDF#39-1425. (See...) Figure 1 ) The luminescent material obtained in Example 4 was analyzed using a fluorescence spectrometer. The emission peak under ultraviolet light excitation was located at 683 nm. Figure 3 Compared with the samples in Examples 1-3, its intensity was significantly improved, and it also exhibited better thermal stability, maintaining 67.1% of its luminescence intensity at 150°C. Figure 4 Comparing the luminescence intensity with Examples 1-3, it can be seen that the combined introduction of Al2O3 and flux H3BO3 can synergistically and significantly enhance the luminescence intensity through changes in the crystal structure environment and the influence of the crystal field on the activation center. (See...) Figure 5 , Figure 6 and Figure 7 ), among which, from Figure 6 It can be clearly seen that Al2O3 and flux H3BO3 synergistically significantly inhibit Sm 3+ The orange glow significantly improves Sm 2+ The near-infrared luminescence intensity.

[0035] Example 5 According to the molar ratio of SiO2 (analytical grade) and Sm2O3 (analytical grade) of 1:0.005, the above raw materials were taken separately, ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, in a H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100 mL / min), the mixture was first calcined at 450℃ for 1 hour, and then sintered at 1400℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0036] The material was subjected to X-ray diffraction tests using an X-ray diffractometer, and no significant difference was found compared with the standard card PDF#39-1425.

[0037] The optical properties of the near-infrared luminescent material obtained in Example 5 were analyzed using a fluorescence spectrometer. Under ultraviolet light excitation at 365 nm, it showed a narrow-band emission peak at 683 nm. Compared with Example 3, there were no other significant changes except for the change in luminescence intensity.

[0038] Example 6 According to the molar ratio of SiO2 (analytical grade), Sm2O3 (analytical grade), and H3BO3 (analytical grade) of 1:0.005:0.03, the raw materials were ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, the mixture was first calcined at 450℃ for 1 hour in an H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100 mL / min), and then sintered at 1400℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0039] The material was subjected to X-ray diffraction tests using an X-ray diffractometer, and no significant difference was found compared with the standard card PDF#39-1425.

[0040] The fluorescent material obtained in Example 6 was analyzed using a fluorescence spectrometer. Under 365 nm ultraviolet light excitation, its emission spectrum showed that the intensity of the narrow band emission peak at 683 nm was increased compared with that in Example 5.

[0041] Example 7 According to the molar ratio of SiO2 (analytical grade), Al2O3 (analytical grade), and Sm2O3 (analytical grade) of 0.94:0.06:0.005, the raw materials were ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, the mixture was first calcined at 450℃ for 1 hour in a H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100 mL / min), and then sintered at 1400℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0042] The material was subjected to X-ray diffraction tests using an X-ray diffractometer, and no significant difference was found compared with the standard card PDF#39-1425.

[0043] The fluorescent material obtained in Example 7 was analyzed using a fluorescence spectroscopy instrument. Compared with the samples in Examples 5 and 6, the intensity of the narrow-band emission peak at 683 nm was improved under 365 nm ultraviolet light excitation. This indicates that the luminescent material can be excited by ultraviolet light to emit red light.

[0044] Example 8 According to the molar ratio of SiO2 (analytical grade), Al2O3 (analytical grade), Sm2O3 (analytical grade), and H3BO3 (analytical grade) of 0.94:0.06:0.005:0.03, the raw materials were separately taken, ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, under a H2 / N2 mixed gas (gas content volume ratio H2:N2=20:80, gas flow rate 100 mL / min), the mixture was first calcined at 450℃ for 1 hour, then sintered at 1400℃ for 6 hours. After the reaction was complete, the mixture was cooled to room temperature in the furnace and thoroughly ground in an agate mortar to obtain the desired Sm2O3. 2+ Doped with near-infrared luminescent materials.

[0045] The material was subjected to X-ray diffraction tests using an X-ray diffractometer, and no significant difference was found compared with the standard card PDF#39-1425.

[0046] The fluorescent material obtained in Example 8 was analyzed using a fluorescence spectrometer. The emission peak under 365 nm ultraviolet light excitation was located at 683 nm, a significant increase in intensity compared to the samples in Examples 5-7. This indicates that the luminescent material can be excited by ultraviolet light to emit red light.

[0047] Example 9 According to the molar ratio of SiO2 (analytical grade) and Sm2O3 (analytical grade) of 1:0.005, the above raw materials were ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, the mixture was first calcined at 450℃ for 1 hour in a H2 / N2 mixed gas (gas content ratio of H2:N2=20:80, gas flow rate of 100 mL / min), and then sintered at 1300℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0048] The material was subjected to X-ray diffraction tests using an X-ray diffractometer, and no significant difference was found compared with the standard card PDF#39-1425.

[0049] The fluorescent material obtained in Example 9 was analyzed using a fluorescence spectrometer. Under 365 nm ultraviolet light excitation, its emission spectrum showed no significant change in emission peak compared to Example 1.

[0050] Example 10 According to the molar ratio of SiO2 (analytical grade), Sm2O3 (analytical grade), and H3BO3 (analytical grade) of 1:0.005:0.03, the above raw materials were taken separately, ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, in an H2 / N2 mixed gas (gas content ratio of H2:N2=20:80, gas flow rate of 100 mL / min), the mixture was first calcined at 450℃ for 1 hour, and then sintered at 1300℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0051] The material was subjected to X-ray diffraction tests using an X-ray diffractometer, and no significant difference was found compared with the standard card PDF#39-1425.

[0052] The fluorescent material obtained in Example 10 was analyzed using a fluorescence spectrometer. Under 365 nm ultraviolet light excitation, its emission spectrum showed that the intensity of the narrow band emission peak at 683 nm was increased compared with that in Example 9.

[0053] Example 11 According to the molar ratio of SiO2 (analytical grade), Al2O3 (analytical grade), and Sm2O3 (analytical grade) of 0.94:0.06:0.005, the raw materials were ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, the mixture was first calcined at 450℃ for 1 hour in a H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100 mL / min), and then sintered at 1300℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0054] The material was subjected to X-ray diffraction tests using an X-ray diffractometer, and no significant difference was found compared with the standard card PDF#39-1425.

[0055] The fluorescent material obtained in Example 11 was analyzed using a fluorescence spectrometer. The emission peak under 365 nm ultraviolet light excitation was located at 685 nm, showing an increase in intensity compared to samples from Examples 9 and 10. This indicates that the luminescent material can be excited by ultraviolet light to emit red light.

[0056] Example 12 According to the molar ratio of SiO2 (analytical grade), Al2O3 (analytical grade), Sm2O3 (analytical grade), and H3BO3 (analytical grade) of 0.94:0.06:0.005:0.03, the raw materials were separately taken, ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, under a H2 / N2 mixed gas (gas content volume ratio H2:N2=20:80, gas flow rate 100 mL / min), the mixture was first calcined at 450℃ for 1 hour, then sintered at 1300℃ for 6 hours. After the reaction was complete, the mixture was cooled to room temperature in the furnace and thoroughly ground in an agate mortar to obtain the desired Sm2O3. 2+ Doped with near-infrared luminescent materials.

[0057] The material was subjected to X-ray diffraction tests using an X-ray diffractometer, and no significant difference was found compared with the standard card PDF#39-1425.

[0058] The fluorescent material obtained in Example 4 was analyzed using a fluorescence spectrometer. The emission peak under 365 nm ultraviolet light excitation was located at 683 nm, a significant increase in intensity compared to the samples in Examples 9-11. This indicates that the luminescent material can be excited by ultraviolet light to emit red light.

[0059] Example 13 According to the molar ratio of SiO2 (analytical grade) and Sm2O3 (analytical grade) of 1:0.005, the above raw materials were ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, in a H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100 mL / min), the mixture was first calcined at 450℃ for 1 hour, and then sintered at 1200℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0060] The material was subjected to X-ray diffraction tests using an X-ray diffractometer, and no significant difference was found compared with the standard card PDF#39-1425.

[0061] The fluorescent material obtained in Example 13 was analyzed using a fluorescence spectrometer. Under 365 nm ultraviolet light excitation, its emission spectrum showed no significant change in peak position compared to Example 1.

[0062] Example 14 According to the molar ratio of SiO2 (analytical grade), Sm2O3 (analytical grade), and H3BO3 (analytical grade) of 1:0.005:0.03, the above raw materials were ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, the mixture was first calcined at 450℃ for 1 hour in an H2 / N2 mixed gas (gas content ratio of H2:N2=20:80, gas flow rate of 100 mL / min), and then sintered at 1200℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0063] The fluorescent material obtained in Example 14 was analyzed using a fluorescence spectrometer. Under 365 nm ultraviolet light excitation, its emission spectrum showed that the intensity of the narrow band emission peak at 688 nm was increased compared with that in Example 13.

[0064] Example 15 According to the molar ratio of SiO2 (analytical grade), Al2O3 (analytical grade), and Sm2O3 (analytical grade) of 0.94:0.06:0.005, the raw materials were ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, the mixture was first calcined at 450℃ for 1 hour in a H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100 mL / min), and then sintered at 1200℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0065] The fluorescent material obtained in Example 15 was analyzed using a fluorescence spectrometer. Compared with the samples in Examples 13 and 14, the intensity of the narrow-band emission peak at 688 nm was improved under 365 nm ultraviolet light excitation. This indicates that the luminescent material can be excited by ultraviolet light to emit red light.

[0066] Example 16 According to the molar ratio of SiO2 (analytical grade), Al2O3 (analytical grade), Sm2O3 (analytical grade), and H3BO3 (analytical grade) of 0.94:0.06:0.005:0.03, the above raw materials were ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, in an H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100 mL / min), the mixture was first calcined at 450℃ for 1 hour, and then sintered at 1200℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0067] The luminescent material obtained in Example 16 was analyzed using a fluorescence spectrometer. The emission peak under 365 nm ultraviolet light excitation was located at 683 nm, a significant increase in intensity compared to the samples in Examples 13-15. This indicates that the luminescent material can be excited by ultraviolet light to emit red light.

[0068] Example 17 According to the molar ratio of SiO2 (analytical grade) and Sm2O3 (analytical grade) of 1:0.008, the above raw materials were ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, in a H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100 mL / min), the mixture was first calcined at 450℃ for 1 hour, and then sintered at 1500℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0069] The luminescent material obtained in Example 17 was analyzed using a fluorescence spectrometer. Under 365 nm ultraviolet light excitation, its emission spectrum was found to be similar to that of Example 1, except for a slight increase in intensity.

[0070] Example 18 According to the molar ratio of SiO2 (analytical grade), Sm2O3 (analytical grade), and H3BO3 (analytical grade) of 1:0.008:0.05, the raw materials were taken separately, ground and mixed in an agate mortar, dried, and then placed in an Al2O3 crucible. In a high-temperature furnace, in a H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100 mL / min), the mixture was first calcined at 450℃ for 1 hour, and then sintered at 1500℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0071] The luminescent material obtained in Example 18 was analyzed using a fluorescence spectrometer. Under 365 nm ultraviolet light excitation, its emission spectrum showed that the intensity of the narrow band emission peak at 688 nm was increased compared with that of Example 1.

[0072] Example 19 According to the molar ratio of SiO2 (analytical grade), Al2O3 (analytical grade), and Sm2O3 (analytical grade) of 0.94:0.06:0.008, the raw materials were ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, the mixture was first calcined at 450℃ for 1 hour in a H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100 mL / min), and then sintered at 1500℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0073] The fluorescent material obtained in Example 19 was analyzed using a fluorescence spectrometer. Compared with the samples in Examples 17-18, the intensity of the narrow-band emission peak at 688 nm was improved under 365 nm ultraviolet light excitation. This indicates that the luminescent material can be excited by ultraviolet light to emit red light.

[0074] Example 20 According to the molar ratio of SiO2 (analytical grade), Al2O3 (analytical grade), Sm2O3 (analytical grade), and H3BO3 (analytical grade) of 0.94:0.06:0.008:0.05, the raw materials were ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, the mixture was first calcined at 450℃ for 1 hour in an H2 / N2 mixed gas (gas content ratio of H2:N2=20:80, gas flow rate of 100 mL / min), and then sintered at 1500℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0075] The fluorescent material obtained in Example 20 was analyzed using a fluorescence spectrometer. Under 365 nm ultraviolet light excitation, its intensity was significantly increased compared to the samples in Examples 17-19. This indicates that the luminescent material can be excited by ultraviolet light to emit red light.

[0076] Example 21 According to the molar ratio of SiO2 (analytical grade), Al2O3 (analytical grade), Sm2O3 (analytical grade), and H3BO3 (analytical grade) of 0.98:0.02:0.005:0.03, the raw materials were ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, the mixture was first calcined at 450℃ for 1 hour in an H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100 mL / min), and then sintered at 1500℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0077] The luminescent material obtained in Example 21 was analyzed using a fluorescence spectrometer, and a narrow-band emission peak at 683 nm was observed under 365 nm ultraviolet light excitation. Compared with Example 4, there were no significant changes except for the change in luminescence intensity. This indicates that the luminescent material can be excited by ultraviolet light to emit red light.

[0078] Example 22 According to the molar ratio of SiO2 (analytical grade), Al2O3 (analytical grade), Sm2O3 (analytical grade), and H3BO3 (analytical grade) of 0.96:0.04:0.005:0.03, the raw materials were ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, the mixture was first calcined at 450℃ for 1 hour in an H2 / N2 mixed gas (gas content volume ratio of H2:N2=20:80, gas flow rate of 100 mL / min), and then sintered at 1500℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature in the furnace and then thoroughly ground in an agate mortar to obtain the desired near-infrared luminescent material.

[0079] The fluorescent material obtained in Example 22 was analyzed using a fluorescence spectrometer, and a narrow emission peak at 683 nm was observed under 365 nm ultraviolet light excitation. Compared with Example 4, there were no significant changes except for the change in luminescence intensity. This indicates that the luminescent material can be excited by ultraviolet light to emit red light.

[0080] Example 23 According to the molar ratio of SiO2 (analytical grade), AlN (analytical grade), Sm2O3 (analytical grade), and H3BO3 (analytical grade) of 0.96:0.04:0.005:0.03, the raw materials were separately taken, ground and mixed in an agate mortar, dried, and then placed into an Al2O3 crucible. In a high-temperature furnace, under a H2 / N2 mixed gas (gas content volume ratio H2:N2=20:80, gas flow rate 100 mL / min), the mixture was first calcined at 450℃ for 1 hour, then sintered at 1500℃ for 6 hours. After the reaction was complete, the mixture was cooled to room temperature in the furnace and thoroughly ground in an agate mortar to obtain the desired Sm2O3. 2+ Doped with near-infrared luminescent materials.

[0081] The fluorescent material obtained in Example 23 was analyzed using a fluorescence spectrometer, and a narrow emission peak at 683 nm was observed under 365 nm ultraviolet light excitation. Compared with Example 4, there were no significant changes except for the change in luminescence intensity. This indicates that the luminescent material can be excited by ultraviolet light to emit red light.

[0082] The embodiments described above are merely preferred embodiments of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various other corresponding changes and modifications based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of the present invention.

Claims

1. A near-infrared luminescent material, as shown in formula (I): Si 1-x Al x B y N z O 2-z : Sm m , Ln n (I); in, Ln is one or more elements from Yb, Eu, Gd, Ce; 0≤x≤0.1, 0≤y≤0.5, 0≤z≤0.5, 0≤m≤0.1, 0≤n≤0.

1.

2. A method for preparing a near-infrared luminescent material, characterized in that, Near-infrared luminescent materials are obtained by mixing Sm precursor, Ln precursor, Al precursor, Si precursor with flux, grinding thoroughly to obtain a mixture, and then carrying out a high-temperature solid-state reaction. The molar ratios of each element in the Sm precursor, Ln precursor, Al precursor, Si precursor, and flux are as follows: The molar ratio of Si, Al, flux, Sm, and Ln is 1-x:x:y:m:n; 0≤x≤0.1, 0≤y≤0.5, 0≤m≤0.1, 0≤n≤0.1; The co-solvent includes H3BO3, and its mass amount is 1-8% of the total mass of the raw materials.

3. The preparation method according to claim 2, characterized in that, The purity of the Sm precursor, Ln precursor, Al precursor, Si precursor, and flux is not less than 99.5%.

4. The preparation method according to claim 2, characterized in that, Sm precursor, Ln precursor, Al precursor, Si precursor and flux are mixed in a certain proportion and reacted at high temperature in a reducing atmosphere. The final product is obtained by grinding after cooling to room temperature.

5. The preparation method according to claim 4, characterized in that, The Sm precursor is one or more of the following: Sm carbonate, Sm oxide, Sm sulfide, Sm halide, Sm boride, Sm oxalate, and Sm nitrate. The Ln precursor is one or more of the following: Ln carbonate, Ln oxide, Ln sulfide, Ln chloride, Ln oxalate, and Ln nitrate. The Al precursor is one or more of Al oxides, Al nitrides, Al chlorides, Al nitrates, and Al carbonates; The Si precursor is one or more of Si oxides and Si nitrides.

6. The preparation method according to claim 4, characterized in that, The reducing atmosphere is one of nitrogen, argon, argon-hydrogen, or a mixture of nitrogen and hydrogen.

7. The preparation method according to claim 4, characterized in that, The high-temperature sintering temperature is 1200~1500℃; the high-temperature sintering time is 1~6h.

8. The application of a near-infrared luminescent material as described in claim 1 or a near-infrared luminescent material prepared by any of the preparation methods described in claims 2-7 in bioimaging, plant growth lighting, high color rendering index white LEDs, and solar cells.

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