An ultrawideband InNbTiO6 near-infrared luminescent material, its preparation method, and a near-infrared light source.

Abstract

This invention provides an ultrawideband InNbTiO6 near-infrared luminescent material, its preparation method, and a near-infrared light source. Its chemical formula is In. 1‑x‑y NbTiO6:xCr 3+ ,yGa 3+ In the formula, 0

Description

Technical Field

[0001] This invention belongs to the field of luminescent materials, and specifically relates to an ultrawideband InNbTiO6 near-infrared luminescent material, its preparation method, and a near-infrared light source. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Broadband near-infrared (NIR) spectroscopy offers advantages such as portability, non-destructive testing, and good tissue penetration, leading to a significant increase in its applications in medical imaging, food analysis, and other fields. The characteristic absorption peaks of organic chemical bonds are mostly located after 900 nm. NIR spectra overlap with the characteristic absorption bands of some organic functional groups XH (X = C, N, O), providing rich structural and compositional information, making it highly suitable for measuring the composition and properties of hydrocarbon organic substances. Therefore, the near-infrared light source used for component analysis must have a long wavelength emission and sufficient emission bandwidth to encompass most vibrational overtones and combination frequencies of the analyte's chemical components. Compared to the narrow-band emission of near-infrared light-emitting diodes (NIR LEDs), typical broadband full-spectrum emitting devices such as tungsten filament lamps and halogen lamps can provide broadband near-infrared emission, but their application is severely limited by their inherent large size, low efficiency, and high cost. Near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs), when matched with suitable near-infrared phosphors, effectively overcome the limitations of other light sources. Therefore, developing near-infrared phosphors with long wavelengths (>900 nm) and ultra-wideband emission has become an urgent problem to be solved. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides an ultra-wideband InNbTiO6 near-infrared luminescent material, its preparation method, and a near-infrared light source. The luminescent material absorbs blue-green light in the 450-600 nm range, exhibiting good matching with the spectra of inexpensive blue and green LED chips, and can be effectively excited by them. Under excitation with 520 nm green light, it yields an ultra-wideband long-wavelength near-infrared emission spectrum with an emission peak located at 948-983 nm (the emission peak varies depending on the Ga content), a full width at half maximum (FWHM) greater than 210 nm, and an emission range covering 700-1400 nm.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides an ultrawideband InNbTiO6 near-infrared luminescent material, the chemical formula of which is In 1-x-yNbTiO6:xCr 3+ ,yGa 3+ In the formula, 0 <x≤0.05,0≤y≤0.4。

[0007] The aforementioned ultrawideband wolframite-type near-infrared luminescent material is a transition metal ion Cr 3+ Ion-doped niobates, transition metal ions Cr 3+ The outer electron configuration is 3d 3 Its luminescence properties are closely related to the surrounding crystal field environment, and the emission wavelength can span from the red region to the near-infrared region. In this invention, Cr... 3+ As a luminescent ion, using InNbTiO6 as the luminescent material matrix, through Cr 3+ Replacing the single In in InNbTiO6 3+ The site yielded InNbTiO6:Cr with ultrawideband long-wavelength emission. 3+ Near-infrared phosphor. Based on this, by controlling Ga 3+ Replace In 3+ The increased content of phosphor reduces lattice distortion, enhances structural stiffness, and improves the luminescence intensity and thermal stability of the phosphor. Thanks to its excellent luminescent properties, it has application potential in the field of near-infrared PC-LED light sources.

[0008] In some implementations, 0.005 ≤ x ≤ 0.05, y = 0.

[0009] In some implementations, x = 0.02, 0 ≤ y ≤ 0.4.

[0010] In some embodiments, the emission spectrum of the luminescent material is in the range of 700-1400 nm.

[0011] A second aspect of the present invention provides a method for preparing an ultrawideband InNbTiO6 near-infrared luminescent material, comprising:

[0012] Oxides or corresponding salts containing In, oxides or corresponding salts containing Nb, oxides or corresponding salts containing Ti, oxides or corresponding salts containing Cr, and oxides or corresponding salts containing Ga are mixed with an organic solvent and ground to obtain a mixed powder.

[0013] Sintering the mixed powder yields an ultrawideband InNbTiO6 near-infrared luminescent material.

[0014] The preparation method of broadband near-infrared luminescent materials adopts the traditional high-temperature solid-state method. The product of this invention is synthesized by the high-temperature solid-state method, which has the advantages of high crystallinity, low cost, simple preparation process, and easy mass production.

[0015] In some embodiments, the oxide or corresponding salt containing element In is In2O3;

[0016] In some embodiments, the oxide or corresponding salt containing element Nb is Nb2O5;

[0017] In some embodiments, the oxide or corresponding salt containing element Ti is TiO2;

[0018] In some embodiments, the oxide or corresponding salt containing element Cr is Cr2O3;

[0019] In some embodiments, the oxide or corresponding salt containing element Ga is Ga2O3.

[0020] In some embodiments, the organic solvent is absolute ethanol.

[0021] In some embodiments, the sintering is carried out under air conditions.

[0022] In some embodiments, the sintering temperature is 1400 - 1500 °C.

[0023] In some embodiments, the sintering time is 8 - 10 h of constant temperature.

[0024] More specifically, it is prepared according to the following steps:

[0025] According to the chemical formula In 1-x NbTiO6:xCr 3+ , with an atomic molar ratio of 0 < x ≤ 0.05, using oxides or corresponding salt raw materials containing elements In, Nb, Ti, and Cr, such as In2O3, Nb2O5, TiO2, and Cr2O3, put the weighed raw materials into a mortar and mix with a certain amount of absolute ethanol, and grind thoroughly to finally obtain a mixed powder. Put the obtained mixed powder into an alumina crucible and heat it to 1400 °C under air, and keep it at a constant temperature for 8 hours. After cooling to room temperature, take out the fired sample and grind it evenly.

[0026] It has been verified that the prepared In 1-x NbTiO6:xCr 3+ phosphor emits broadband near-infrared light emission of 700 - 1400 nm under the excitation of 520 nm. Among the series of In 1-x NbTiO6:xCr 3+ products, the product with x = 0.02 has the strongest luminescence intensity.

[0027] Based on the above optimized Cr 3+ ion doping concentration, a series of nominal In 0.98- yNbTiO6:0.02Cr 3+ ,yGa 3+ Phosphors with (0≤y≤0.4) are prepared according to the following steps:

[0028] According to the chemical formula In 0.98-y NbTiO6:0.02Cr 3+ ,yGa 3+ With an atomic molar ratio of (0≤y≤0.4), oxides or corresponding salts of elements In, Nb, Ti, Ga, and Cr, such as In₂O₃, Nb₂O₅, TiO₂, Ga₂O₃, and Cr₂O₃, were used as raw materials. The weighed raw materials were placed in a mortar and mixed with a certain amount of anhydrous ethanol, and then thoroughly ground to obtain a mixed powder. The resulting mixed powder was placed in an alumina crucible and heated to 1400℃ in air, maintaining this temperature for 8 hours. After cooling to room temperature, the calcined sample was removed and ground uniformly.

[0029] Verified In 3+ Be Ga 3+ After replacement, the original phase structure remains unchanged while improving emission intensity and luminescence thermal stability in a series of In 0.98-y NbTiO6:0.02Cr 3+ ,yGa 3+ In the product, y = 0.4 (In) 0.58 NbTiO6:0.02Cr 3+ 0.4Ga 3+ The product has the strongest luminous intensity and is the only one that has not replaced In. 0.98 NbTiO6:0.02Cr 3+ The intensity is 2.3 times that of the standard. Furthermore, the thermal stability increased from 22.33%@400K to 41.25%@400K, and the emission peak shifted from 969nm to 934nm. Although the full width at half maximum (FWHM) decreased from 231nm to 217nm, it is still greater than 200nm, which is considered ultra-wideband near-infrared emission.

[0030] A third aspect of the present invention provides a near-infrared light source, comprising: a light source and a near-infrared phosphor, wherein the near-infrared phosphor is the aforementioned ultra-wideband InNbTiO6 near-infrared luminescent material or an ultra-wideband InNbTiO6 near-infrared luminescent material prepared by the aforementioned method, and the light source is a blue or green LED chip.

[0031] Beneficial effects of the present invention

[0032] (1) In this invention, InNbTiO6 is selected as the matrix, and Cr 3+ As activator ions, a series of In ions were prepared using a traditional high-temperature solid-state method. 1-x NbTiO6:xCr 3+Ultra-wideband long-wavelength near-infrared light emitting phosphor with an emission peak of up to 965nm and a half-peak width of over 200nm.

[0033] (2) This invention utilizes concentration optimization to obtain the optimal phosphor In 0.98 NbTiO6:0.02Cr 3+ Through Ga 3+ Occupy In 3+ The cation substitution strategy at the site provides a stable coordination environment, reduces lattice distortion, and improves luminescence intensity and thermal stability. At the same time, it can still obtain ultra-wideband long-wavelength near-infrared phosphors (peak value > 930 nm, full width at half maximum > 210 nm). Attached Figure Description

[0034] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. Exemplary embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0035] Figure 1 .In 1-x NbTiO6:xCr 3+ The X-ray diffraction pattern was compared with that of the standard card, where 0.005 ≤ x ≤ 0.05;

[0036] Figure 2 .In 1-x NbTiO6:xCr 3+ The emission spectrum, where 0.005 ≤ x ≤ 0.05;

[0037] Figure 3 .In 0.98-y NbTiO6:0.02Cr 3+ ,yGa 3+ The X-ray diffraction pattern is compared with the standard card, where 0≤y≤1;

[0038] Figure 4 .In 0.98-y NbTiO6:0.02Cr 3+ ,yGa 3+ The emission spectrum and the changes in peak value and half-maximum width, where y = 0, 0.05, 0.1, 0.2, 0.4;

[0039] Figure 5 .In 0.98-y NbTiO6:0.02Cr 3+ ,yGa 3+ The emission spectrum varies with temperature from 100K to 450K, where y = 0, 0.2, 0.4. Detailed Implementation

[0040] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of the present invention.

[0041] Terminology Explanation:

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

[0043] In refers to indium, a metallic element.

[0044] Nb refers to niobium, a metallic element.

[0045] Ti refers to titanium, a metallic element.

[0046] O stands for oxygen, a nonmetallic element.

[0047] Cr refers to chromium, a metallic element.

[0048] Ga refers to gallium, a metallic element.

[0049] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention and not limitations thereof.

[0050] Example 1: In 1-x-y NbTiO6:xCr 3+ ,yGa 3+ Let x = 0.005, 0.01, 0.02, 0.03, 0.05, and y = 0.

[0051] Weigh out 0.5553 g of In₂O₃, 0.5316 g of Nb₂O₅, 0.3195 g of TiO₂, and 0.0015 g (x = 0.005), 0.0030 g (x = 0.01), 0.0061 g (x = 0.02), 0.0091 g (x = 0.03), and 0.0152 g (x = 0.05) of Cr₂O₃. Place these ingredients in a mortar and mix with a certain amount of anhydrous ethanol. Grind thoroughly to obtain a mixed powder. Place the resulting mixed powder into an alumina crucible and heat to 1400 °C in air, maintaining this temperature for 8 hours. After cooling to room temperature, remove the calcined sample and grind it evenly to obtain an ultrawideband near-infrared emitting phosphor. Figure 1 The X-ray powder diffraction pattern of the material sample prepared according to the technical solution of this embodiment is compared with the standard card PDF#83-1780. The results show that there is no TiO2 impurity phase, and the prepared material is a pure phase InNbTiO6. The emission spectrum obtained under 520nm excitation according to the technical solution of Example 1 is as follows. Figure 2The near-infrared emitting material exhibits the strongest luminescence in the embodiment with x=0.02; the emission peak covers an ultra-wide range of 700-1400nm, with a peak emission value reaching 965nm and a half-maximum width at half-maximum of 231nm.

[0052] Example 2: In 1-x-y NbTiO6:xCr 3+ ,yGa 3+ Let x = 0.02, y = 0, 0.05, 0.1, 0.2, 0.4.

[0053] Weigh out 0.5553 g (y=0), 0.5275 g (y=0.05), 0.4997 g (y=0.1), 0.4442 g (y=0.2), 0.3332 g (y=0.4) of In₂O₃, 0.5316 g of Nb₂O₅, 0.3195 g of TiO₂, 0.0061 g (x=0.02) of Cr₂O₃, and 0 g (y=0), 0.0187 g (y=0.05), 0.0375 g (y=0.1), 0.0750 g (y=0.2), and 0.1500 g (y=0.4) of Ga₂O₃ and place them in a mortar. Mix with a certain amount of anhydrous ethanol and grind thoroughly to obtain a mixed powder. Place the obtained mixed powder in an alumina crucible and heat it to 1400 °C in air, and maintain the temperature for 8 hours. After cooling to room temperature, the calcined sample is removed and ground evenly to obtain the optimized ultrawideband near-infrared emitting phosphor. Figure 3 The X-ray powder diffraction pattern of the material sample prepared according to the technical solution of this embodiment is compared with the standard card PDF#83-1780. The diffraction peaks are shifted to larger angles, indicating that the smaller Ga radius... 3+ Successfully replaced the larger radius In 3+ , enters the crystal lattice; when Ga 3+ When the content exceeds 0.4, a phase transition occurs. Therefore, to maintain the original structure, the value of y is ≤0.4. The emission spectrum under 520nm green light excitation was obtained according to the technical solution of Example 2 (see...). Figure 4 ), with Ga 3+ With increasing content, the emission peak position of this ultrawideband long-wavelength near-infrared emitting phosphor gradually blue-shifted from 969 nm to 934 nm, the full width at half maximum (FWHM) decreased from 231 nm to 217 nm, and the emission intensity increased by 2.3 times. See also Figure 5 Ga 3+ The introduction of [a specific ingredient] improved the luminescence thermal stability of the phosphor, increasing it from 22.33%@400K (y=0) to 41.25%@400K (y=0.4).

[0054] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An ultrawideband InNbTiO6 near-infrared luminescent material, characterized in that, Its chemical formula is In 1-x-y NbTiO6:xCr 3+ ,yGa 3+ In the formula, 0 < x ≤ 0.05, 0 ≤ y ≤ 0.

4.

2. The ultra-wideband InNbTiO6 near-infrared luminescent material as described in claim 1, characterized in that, 0.005≤x ≤0.05, y = 0.

3. The ultra-wideband InNbTiO6 near-infrared luminescent material as described in claim 1, characterized in that, x = 0.02, 0 ≤ y ≤ 0.

4.

4. The ultrawideband InNbTiO6 near-infrared luminescent material as described in claim 1, characterized in that, The emission spectrum of the luminescent material is in the range of 700-1400 nm.

5. A method for preparing the ultrawideband InNbTiO6 near-infrared luminescent material as described in any one of claims 1-4, characterized in that, include: Oxides or corresponding salts containing In, oxides or corresponding salts containing Nb, oxides or corresponding salts containing Ti, oxides or corresponding salts containing Cr, and oxides or corresponding salts containing Ga are mixed with an organic solvent and ground to obtain a mixed powder. Sintering the mixed powder yields an ultrawideband InNbTiO6 near-infrared luminescent material.

6. The preparation method of the ultrawideband InNbTiO6 near-infrared luminescent material as described in claim 5, characterized in that, The oxide or corresponding salt containing element In is In2O3; Alternatively, the oxide or corresponding salt containing element Nb is Nb₂O₅; Alternatively, the oxide or corresponding salt containing element Ti is TiO2; Alternatively, the oxide or corresponding salt containing element Cr, Cr2O3; Alternatively, the oxide or corresponding salt containing element Ga is Ga2O3.

7. The preparation method of the ultrawideband InNbTiO6 near-infrared luminescent material as described in claim 5, characterized in that, The organic solvent is anhydrous ethanol.

8. The preparation method of the ultrawideband InNbTiO6 near-infrared luminescent material as described in claim 5, characterized in that, The sintering is carried out under air conditions.

9. The preparation method of the ultrawideband InNbTiO6 near-infrared luminescent material as described in claim 5, characterized in that, The sintering temperature is maintained at 1400-1500 ℃ for 8-10 h.

10. A near-infrared light source, characterized in that, include: The light source and the near-infrared phosphor, wherein the near-infrared phosphor is the ultra-wideband InNbTiO6 near-infrared luminescent material according to any one of claims 1-4 or the ultra-wideband InNbTiO6 near-infrared luminescent material prepared by the preparation method according to any one of claims 5-9, and the light source is a blue or green LED chip.

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