Broadband near-infrared fluorescent powder of Al < 3 + > substituted and modified Fe < 3 + > doped germanate, preparation method of broadband near-infrared fluorescent powder and near-infrared light source
By replacing Fe3+ with Al3+ to modify germanate phosphors, the problems of low efficiency and poor thermal stability of existing near-infrared phosphors are solved, achieving high-efficiency near-infrared light emission and biosafety, making them suitable for night vision and bioimaging.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-15
- Publication Date
- 2026-04-03
AI Technical Summary
Existing Fe3+-doped near-infrared phosphors suffer from low internal quantum efficiency, insufficient external quantum efficiency, and poor thermal stability, making it difficult to balance broadband emission and biosafety, thus limiting their application in the near-infrared field.
Broadband near-infrared phosphors using Al3+-substituted modified Fe3+-doped germanate were prepared by a high-temperature solid-state method. Their chemical composition and crystal structure were optimized to enable them to emit near-infrared light of 700–740 nm under excitation of 200–500 nm, with an internal quantum efficiency of over 90% and a luminescence intensity retention rate of over 85% at 150 °C.
It achieves efficient near-infrared light emission, possesses excellent thermal stability and biosafety, and is suitable for night vision and bioimaging, especially demonstrating excellent tissue penetration ability in vascular visualization and night vision imaging.
Smart Images
Figure CN121780158A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of luminescent materials technology, specifically to an Al 3+ Replacement modified Fe 3+ Broadband near-infrared phosphors doped with germanates, their preparation methods, and near-infrared light sources. Background Technology
[0002] The unique properties of near-infrared light, including minimal biological damage and strong tissue penetration, make it indispensable for applications in biomedical imaging, materials analysis, and night vision systems. The application of near-infrared light fundamentally relies on the interaction of light and matter at the molecular level, enabling non-destructive analysis of various material systems. In recent years, to address the limitations of traditional near-infrared light sources, such as large size, short lifespan, low energy efficiency, and high operating temperature, priority has been given to developing high-efficiency broadband near-infrared light sources, particularly near-infrared phosphorescent light-emitting diodes (LEDs).
[0003] Near-infrared phosphors are the core component of near-infrared PC-LEDs. To date, many rare-earth and transition metal ions (such as Eu) have been used in this process. 2+ Er 3+ ,Yb 3+ ,Cr 3+ ,Fe 3+ Eu has been studied as a luminescent center in inorganic matrices to achieve broadband near-infrared emission. However, Eu... 2+ Activated phosphors primarily emit light in the visible region and have limited near-infrared properties. Lanthanide ions (Er 3+ ,Yb 3+ Cr emits near-infrared light through 4f-4f transitions, but due to parity limitations, absorption is weak and the emission band is narrow. In recent years, Cr... 3+ It is considered the most promising activator because it can provide an absorption band that matches commercial chips and tunable broadband near-infrared emission. Despite these advantages, Cr 3+ Oxidation converts it into toxic Cr. 6+ It poses significant safety risks to biological and environmental applications.
[0004] Therefore, providing a green and safe synthesis method to prepare broadband near-infrared fluorescent materials with high energy efficiency and excellent thermal stability to expand their application in the near-infrared field is of great significance. Summary of the Invention
[0005] The purpose of this invention is to provide an Al 3+ Replacement modified Fe 3+ Broadband near-infrared phosphors doped with germanates, their preparation methods, and near-infrared light sources, targeting existing Fe... 3+Due to the technical drawbacks of low internal quantum efficiency, insufficient external quantum efficiency, poor thermal stability, and difficulty in balancing broadband emission and biosafety, NIRpc-LEDs based on this phosphor can be used in multiple fields such as night vision, bioimaging, and non-destructive testing, and exhibit excellent tissue penetration capabilities, especially in vascular visualization and night vision imaging.
[0006] In a first aspect, the present invention discloses a broadband near-infrared phosphor with the chemical formula: A3Ga 2-y Al y GeO8:xFe 3+ Where A is one or more of Mg, Ca, Sr, and Ba, and x and y represent Fe. 3+ Al 3+ The mole fraction of y is in the range of 0.1 ≤ y ≤ 2.0 and 0.001 ≤ x ≤ 0.018.
[0007] Preferably, the matrix lattice of the broadband near-infrared phosphor is orthorhombic, and the space group is Imma (number 74).
[0008] Preferably, the value of x is in the range of 0.004≤x≤0.008, and more preferably, x is 0.006; the value of y is in the range of 1.2≤y≤1.8, and more preferably, y is 1.6; under these preferred parameters, the quantum efficiency of the broadband near-infrared phosphor exceeds 90%, and the luminescence intensity at 150℃ remains above 85% of that at room temperature.
[0009] Preferably, the broadband near-infrared phosphor has an excitation wavelength range of 200–500 nm and an emission wavelength range of 650–850 nm.
[0010] An Al according to any one of claims 1 to 4 3+ Replacement modified Fe 3+ A method for preparing broadband near-infrared phosphors doped with germanate, characterized in that the preparation method includes the following steps:
[0011] Step 1: Sinter a mixture containing A source, Ga source, Al source, Ge source, and Fe source to obtain a sintered body; wherein:
[0012] The A source is selected from oxides or nitrates of A (A is one or more of Mg, Ca, Sr, and Ba); the Ga source is selected from oxides or nitrates of Ga; the Al source is selected from oxides or nitrates of Al; the Ge source is selected from oxides of Ge; and the Fe source is selected from oxides of Fe.
[0013] Step 2: Grind the sintered body thoroughly to obtain the broadband near-infrared phosphor.
[0014] A second aspect of the present invention discloses an Al 3+ Replacement modified Fe 3+ A method for preparing broadband near-infrared phosphors doped with germanate, characterized in that the preparation method includes the following steps:
[0015] Step 1: Sinter a mixture containing A source, Ga source, Al source, Ge source, and Fe source to obtain a sintered body; wherein:
[0016] The A source is selected from oxides or nitrates of A (A is one or more of Mg, Ca, Sr, and Ba); the Ga source is selected from oxides or nitrates of Ga; the Al source is selected from oxides or nitrates of Al; the Ge source is selected from oxides of Ge; and the Fe source is selected from oxides of Fe.
[0017] Step 2: Grind the sintered body thoroughly to obtain the broadband near-infrared phosphor.
[0018] Preferably, the molar ratio of A, Ga, Al, Ge, and Fe in the A source, Ga source, Al source, Ge source, and Fe source is 3:(2-y):y:1:x.
[0019] Preferably, the purity of the oxide or nitrate of A, the oxide or nitrate of Ga, the oxide or nitrate of Al, the oxide of Ge, and the oxide of Fe is not less than 99.9%.
[0020] Preferably, the sintering temperature is 800–1600℃, the holding time is 3–8h, and the heating rate is 5–15℃ / min.
[0021] Preferably, the grinding particle size of the sintered body is 200-600 mesh.
[0022] A third aspect of the present invention discloses an Al 3+ Replacement modified Fe 3+ Application of germanate-doped broadband near-infrared phosphors in near-infrared light sources.
[0023] The beneficial effects of this invention are:
[0024] This invention utilizes Al 3+ Replacement optimization Fe 3+ Germanate phosphors are doped to emit near-infrared light at 700–740 nm under 200–500 nm excitation, exhibiting an internal quantum efficiency exceeding 90% and a luminescence intensity retention rate exceeding 85% at 150 °C, thus solving the problems of low efficiency and poor thermal stability in existing products; Fe 3+It is non-toxic to organisms, and the near-infrared light source prepared based on it can achieve night vision and vein imaging. It is prepared by high-temperature solid-state method, which is simple and the raw materials are readily available, making it suitable for industrial production. Attached Figure Description
[0025] Figure 1 Figure 1 These are comparison images of the X-ray diffraction patterns of the samples described in Examples 1-5 and the standard card PDF#79–0265;
[0026] Figure 2 These are the emission spectra of the samples described in Examples 1 to 5;
[0027] Figure 3 This is the temperature-dependent emission spectrum of the sample described in Example 3 when excited by near-ultraviolet light at 290 nm;
[0028] Figure 4 These are the emission spectra of Examples 3 and 6-5;
[0029] Figure 5 This is a comparative bar chart of the internal quantum efficiency, absorption efficiency, and external quantum efficiency of Examples 3 and 9;
[0030] Figure 6 These are the temperature-varying luminescence intensity curves of Examples 3 and 9 under near-ultraviolet light excitation at 290 nm. Detailed Implementation
[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.
[0032] Unless otherwise specified, the experimental methods described in the following examples are generally performed under conventional conditions in the art or as recommended by the manufacturer; the raw materials and reagents used are all commercially available from the conventional market unless otherwise specified.
[0033] Any non-substantial changes and substitutions made by those skilled in the art based on this invention shall fall within the scope of protection claimed by this invention.
[0034] Example 1
[0035] This embodiment prepares a broadband near-infrared fluorescent material, and the specific process is as follows:
[0036] Based on the following chemical composition: Mg3Ga2GeO8:0.001Fe 3+MgO, Ga2O3, Ge2O3, and Fe2O3 were weighed separately and thoroughly mixed and ground in an agate mortar. The resulting homogeneous mixture was then transferred to an alumina crucible and sintered in a box furnace at 1300℃ for 5 hours, with a heating rate of 10℃ per minute. After naturally cooling to room temperature in the furnace, the sample was removed and ground again to obtain the final product.
[0037] Example 2
[0038] This embodiment prepares a broadband near-infrared fluorescent material, and the specific process is as follows:
[0039] Based on the following chemical composition: Mg3Ga2GeO8:0.003Fe 3+ MgO, Ga2O3, Ge2O3, and Fe2O3 were weighed separately and thoroughly mixed and ground in an agate mortar. The resulting homogeneous mixture was then transferred to an alumina crucible and sintered in a box furnace at 1300℃ for 5 hours, with a heating rate of 10℃ per minute. After naturally cooling to room temperature in the furnace, the sample was removed and ground again to obtain the final product.
[0040] Example 3
[0041] This embodiment prepares a broadband near-infrared fluorescent material, and the specific process is as follows:
[0042] Based on the following chemical composition: Mg3Ga2GeO8:0.006Fe 3+ MgO, Ga2O3, Ge2O3, and Fe2O3 were weighed separately and thoroughly mixed and ground in an agate mortar. The resulting homogeneous mixture was then transferred to an alumina crucible and sintered in a box furnace at 1300℃ for 5 hours, with a heating rate of 10℃ per minute. After naturally cooling to room temperature in the furnace, the sample was removed and ground again to obtain the final product.
[0043] Example 4
[0044] This embodiment prepares a broadband near-infrared fluorescent material, and the specific process is as follows:
[0045] Based on the following chemical composition: Mg3Ga2GeO8:0.009Fe 3+ MgO, Ga2O3, Ge2O3, and Fe2O3 were weighed separately and thoroughly mixed and ground in an agate mortar. The resulting homogeneous mixture was then transferred to an alumina crucible and sintered in a box furnace at 1300℃ for 5 hours, with a heating rate of 10℃ per minute. After naturally cooling to room temperature in the furnace, the sample was removed and ground again to obtain the final product.
[0046] Example 5
[0047] This embodiment prepares a broadband near-infrared fluorescent material, and the specific process is as follows:
[0048] Based on the following chemical composition: Mg3Ga2GeO8:0.018Fe 3+ MgO, Ga2O3, Ge2O3, and Fe2O3 were weighed separately and thoroughly mixed and ground in an agate mortar. The resulting homogeneous mixture was then transferred to an alumina crucible and sintered in a box furnace at 1300℃ for 5 hours, with a heating rate of 10℃ per minute. After naturally cooling to room temperature in the furnace, the sample was removed and ground again to obtain the final product.
[0049] Example 6
[0050] This embodiment prepares a broadband near-infrared fluorescent material, and the specific process is as follows:
[0051] According to the following chemical composition: Mg3Ga 1.6 Al 0.4 GeO8:0.006Fe 3+ MgO, Ga2O3, Ge2O3, Al2O3, and Fe2O3 were weighed separately and thoroughly mixed and ground in an agate mortar. The resulting homogeneous mixture was then transferred to an alumina crucible and sintered in a box furnace at 1300℃ for 5 hours, with a heating rate of 10℃ per minute. After naturally cooling to room temperature in the furnace, the sample was removed and ground again to obtain the final product.
[0052] Example 7
[0053] This embodiment prepares a broadband near-infrared fluorescent material, and the specific process is as follows:
[0054] According to the following chemical composition: Mg3Ga 1.2 Al 0.8 GeO8:0.006Fe 3+ MgO, Ga2O3, Ge2O3, Al2O3, and Fe2O3 were weighed separately and thoroughly mixed and ground in an agate mortar. The resulting homogeneous mixture was then transferred to an alumina crucible and sintered in a box furnace at 1300℃ for 5 hours, with a heating rate of 10℃ per minute. After naturally cooling to room temperature in the furnace, the sample was removed and ground again to obtain the final product.
[0055] Example 8
[0056] This embodiment prepares a broadband near-infrared fluorescent material, and the specific process is as follows:
[0057] According to the following chemical composition: Mg3Ga 0.8 Al 1.2 GeO8:0.006Fe 3+MgO, Ga2O3, Ge2O3, Al2O3, and Fe2O3 were weighed separately and thoroughly mixed and ground in an agate mortar. The resulting homogeneous mixture was then transferred to an alumina crucible and sintered in a box furnace at 1300℃ for 5 hours, with a heating rate of 10℃ per minute. After naturally cooling to room temperature in the furnace, the sample was removed and ground again to obtain the final product.
[0058] Example 9
[0059] This embodiment prepares a broadband near-infrared fluorescent material, and the specific process is as follows:
[0060] According to the following chemical composition: Mg3Ga 0.4 Al 1.6 GeO8:0.006Fe 3+ MgO, Ga2O3, Ge2O3, Al2O3, and Fe2O3 were weighed separately and thoroughly mixed and ground in an agate mortar. The resulting homogeneous mixture was then transferred to an alumina crucible and sintered in a box furnace at 1300℃ for 5 hours, with a heating rate of 10℃ per minute. After naturally cooling to room temperature in the furnace, the sample was removed and ground again to obtain the final product.
[0061] Example 10
[0062] This embodiment prepares a broadband near-infrared fluorescent material, and the specific process is as follows:
[0063] Based on the following chemical composition: Mg3Al2GeO8:0.006Fe 3+ MgO, Ge2O3, Al2O3, and Fe2O3 were weighed separately and thoroughly mixed and ground in an agate mortar. The resulting homogeneous mixture was then transferred to an alumina crucible and sintered in a box furnace at 1300℃ for 5 hours, with a heating rate of 10℃ per minute. After naturally cooling to room temperature in the furnace, the sample was removed and ground again to obtain the final product.
[0064] Test characterization
[0065] Figure 1 These are comparison images of the X-ray diffraction patterns of the samples described in Examples 1-5 with the standard card PDF#79–0265. The images show that when a very small amount of Fe is incorporated into the germanate matrix... 3+ At that time, the diffraction peak positions of the sample corresponded well with those of the standard card PDF#79–0265, and no impurity phases were generated, indicating that the obtained sample was a pure phase and its crystal structure had not changed.
[0066] Figure 2These are the emission spectra of the samples described in Examples 1-5. As can be seen from the above figures, the phosphor, when excited by near-ultraviolet light at 290 nm, can emit broadband near-infrared light with a wavelength range of 650–850 nm. Among them, Example 3 exhibits the highest luminescence intensity.
[0067] Figure 3 This is the temperature-dependent emission spectrum of the sample described in Example 3 when excited by near-ultraviolet light at 290 nm.
[0068] The sample's luminescence intensity remained at 88.4% of that at room temperature even at 150°C, demonstrating excellent thermal stability.
[0069] Figure 4 These are the emission spectra of Examples 3 and 6-5. As can be seen from the above figures, the phosphor, when excited by near-ultraviolet light at 290 nm, can emit broadband near-infrared light with a wavelength range of 650-850 nm. Among them, Example 9 exhibits the highest luminescence intensity.
[0070] Figure 5 This is a bar chart comparing the internal quantum efficiency, absorption efficiency, and external quantum efficiency of Examples 3 and 9. As can be seen from the chart, the internal quantum efficiency of the broadband near-infrared phosphor in Example 9 increased from 16.4% to 92.6% compared to Example 3, and the external quantum efficiency increased from 7.33% to 29.3%.
[0071] Figure 6 These are the temperature-dependent luminescence intensity curves of Examples 3 and 9 under near-ultraviolet light excitation at 290 nm. As can be seen from the above figures, the thermal stability of the broadband near-infrared phosphor in Example 9 at 150 °C increased from 88.4% to 89.4% compared to Example 3.
[0072] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0073] The accompanying drawings of the embodiments disclosed in this invention only involve structures relevant to the embodiments disclosed in this invention. Other structures can be referred to with common designs. Unless otherwise specified, the same embodiment and different embodiments of this invention can be combined with each other.
[0074] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. An Al 3+ Replacement modified Fe 3+ Broadband near-infrared phosphors doped with germanates, characterized in that: The chemical formula of the broadband near-infrared phosphor is: A3Ga 2-y Al y GeO8:xFe 3+ Where A is one or more of Mg, Ca, Sr, and Ba, and x and y represent Fe. 3+ Al 3+ The mole fraction of y is in the range of 0.1 ≤ y ≤ 2.0 and 0.001 ≤ x ≤ 0.
018.
2. The Al according to claim 1 3+ Replacement modified Fe 3+ Broadband near-infrared phosphors doped with germanates, characterized in that: The matrix lattice of the broadband near-infrared phosphor is orthorhombic, and the space group is Imma (number 74).
3. The Al according to claim 1 3+ Replacement modified Fe 3+ Broadband near-infrared phosphors doped with germanates, characterized in that: The value of x is in the range of 0.004≤x≤0.008, preferably x is 0.006; the value of y is in the range of 1.2≤y≤1.8, preferably y is 1.6; under these preferred parameters, the quantum efficiency of the broadband near-infrared phosphor exceeds 90%, and the luminescence intensity at 150℃ remains above 85% of that at room temperature.
4. The Al according to claim 1 3+ Replacement modified Fe 3+ Broadband near-infrared phosphors doped with germanates, characterized in that: The broadband near-infrared phosphor has an excitation wavelength range of 200–500 nm and an emission wavelength range of 650–850 nm.
5. An Al according to any one of claims 1 to 4 3+ Replacement modified Fe 3+ A method for preparing broadband near-infrared phosphors doped with germanates, characterized in that, The preparation method includes the following steps: Step 1: Sinter a mixture containing A source, Ga source, Al source, Ge source, and Fe source to obtain a sintered body; wherein: The A source is selected from oxides or nitrates of A (A is one or more of Mg, Ca, Sr, and Ba); the Ga source is selected from oxides or nitrates of Ga; the Al source is selected from oxides or nitrates of Al; the Ge source is selected from oxides of Ge; and the Fe source is selected from oxides of Fe. Step 2: Grind the sintered body thoroughly to obtain the broadband near-infrared phosphor.
6. The Al according to claim 5 3+ Replacement modified Fe 3+ A method for preparing broadband near-infrared phosphors doped with germanates, characterized in that: The molar ratio of A, Ga, Al, Ge, and Fe in the A source, Ga source, Al source, Ge source, and Fe source is 3:(2-y):y:1:x.
7. The Al according to claim 5 3+ Replacement modified Fe 3+ A method for preparing broadband near-infrared phosphors doped with germanates, characterized in that: The purity of the oxide or nitrate of A, the oxide or nitrate of Ga, the oxide or nitrate of Al, the oxide of Ge, and the oxide of Fe is not less than 99.9%.
8. The Al according to claim 5 3+ Replacement modified Fe 3+ A method for preparing broadband near-infrared phosphors doped with germanates, characterized in that: The sintering temperature is 800–1600℃, the holding time is 3–8h, and the heating rate is 5–15℃ / min.
9. The Al according to claim 5 3+ Replacement modified Fe 3+ A method for preparing broadband near-infrared phosphors doped with germanates, characterized in that: The grinding particle size of the sintered body is 200-600 mesh.
10. The broadband near-infrared phosphor according to any one of claims 1 to 3, and the Al prepared by any one of claims 4 to 9. 3+ Replacement modified Fe 3+ Application of germanate-doped broadband near-infrared phosphors in near-infrared light sources.