KR102391310B1 - Near-infrared fluorescent powder and light-emitting device containing the fluorescent powder - Google Patents

Abstract

The present invention belongs to the field of light emitting material technology, and more particularly relates to a near-infrared fluorescent powder, and a method for manufacturing the same and a light emitting device containing the fluorescent powder are further disclosed. The near-infrared fluorescent powder of the present invention includes an inorganic compound having a constitutional formula of A _x R _p O _r , the compound has an A _x R _p O _r structure as a substrate, and a specified rare earth ion or transition metal ion is mixed. Through this, the excitation peak of the prepared fluorescent powder is located at 350 to 750 nm, realizes wide emission under excitation of ultraviolet light, blue-ray or red light, and the emission main peak is located at 700 to 1600 nm. By constructing a solid solution through ion substitution, etc., and due to the effect of crystal electric field splitting, it is possible to prepare near-infrared fluorescent powder materials with different emission wavelengths, and not only to improve the emission intensity of the fluorescent powder, but also to increase the controllability of the spectrum. It has been realized, and the scope of its application has been further expanded.

Description

Near-infrared fluorescent powder and light-emitting device containing the fluorescent powder

The present invention is filed based on a Chinese patent with an application number of 201810969498.0 and an application date of August 23, 2018, requesting priority to the Chinese patent application, and all contents of the Chinese patent application are cited in the present invention for reference do.

BACKGROUND OF THE INVENTION Field of the Invention [0001] The present invention relates to the field of luminescent material technology, and more particularly to near-infrared fluorescent powder, and further discloses a method for producing the same, and a light emitting device containing the fluorescent powder.

In recent years, near-infrared spectrum technology has developed rapidly in applications such as face recognition, iris recognition, crime prevention monitor, laser radar, medical examination, and 3D sensor. It has established itself as an international research focus with a series of advantages such as small back.

Currently, the main implementation method of near-infrared LED is a method of using a near-infrared semiconductor chip. The core technology of near-infrared chip technology has already been monopolized by foreign countries, and there are problems such as high cost and immature technology. Therefore, a near-infrared LED of a Blu-ray chip composite near-infrared light emitting material has been released, and the implementation method of the complex packaging has advantages such as a simple manufacturing process, low cost, and high luminous efficiency, and has received wide international attention. Therefore, it is very important to develop a new type of near-infrared light emitting material of different breakage for infrared LEDs in realizing the diversified application demands.

Near-infrared fluorescent powder with a peak wavelength of 780 to 1700 nm can be applied in many fields such as food inspection, face recognition, iris recognition, crime prevention monitor, laser radar, medical examination and 3D sensor, etc., and has the widest practical application value, different It can satisfy application demands. The titanium dioxide type composite oxide has a stable crystal structure and is replaced by other ionic moieties with approximate radii, so that the crystal structure is basically unchanged. Therefore, a titanium dioxide system in which rare earth ions and transition metal ions are mixed, replaced through ions, to establish a solid solution, and a broadband or multi-spectrum near-infrared fluorescent powder having an emission main peak of 780 to 1700 nm is prepared, It is adjustable and controllable, and by obtaining well-formed and controllable grains through improving the reaction conditions, the application standard is achieved, and has a relatively wide application prospect.

For example, Chinese Patent ^CN107573937A discloses a borate fluorescent powder having the same structure as MBO ₃ :Cr ³⁺ , among which M is Sc, Al, Lu, Gd or Y element, and the fluorescent powder is blue-ray (420-520 nm) It can be effectively excited by the light and emit near-infrared light in the range of 700 to 920 nm. When M is Al, Lu, Gd or Y, the emission spectra are all similar to those in which M is Sc. In addition, the above patent mainly studied the method for preparing MBO ₃ :Cr ^{3 +} , and studied and discussed the effect of reaction temperature and reaction time, but did not discuss the spectral performance.

Also, for example, in the non-patent literature "Photoluminescence Properties of a ScBO ₃ :Cr ^{3 +} Phosphor and Its Applications for Broadband Near-infrared LEDs" [J]. RSC Adv, 2018, 8, 12035-12042. disclosed a near-infrared fluorescent powder ^ScBO ₃ :Cr ³⁺ , which realizes near-infrared wide emission with a main peak located at 800 nm under excitation of a Blu-ray chip, and quantum The efficiency is 65%. The packaging uses the near-infrared fluorescent powder and the Blu-ray chip, the output power of the near-infrared light is 26mW, and the energy conversion efficiency thereof is relatively low, only 7%.

As you can see, the near ^- infrared powder MBO ₃ :Cr ³⁺ developed in the prior art has an emission main peak located at most 800 nm, and the emission wavelength range is narrow, and the emission intensity is relatively low, and the emission wavelength is not adjustable. Accordingly, the application range and application effect of the fluorescent powder were limited.

To this end, the technical problem to be solved in the present invention is to provide a near-infrared fluorescent powder, the near-infrared fluorescent powder has broadband or multi-spectral emission, the spectrum is adjustable, has the advantage of high luminous efficiency, and It can meet the material performance requirements of fields such as recognition, iris recognition, crime prevention monitor, laser radar, medical examination, and 3D sensor.

The second technical problem to be solved in the present invention is to provide a light emitting device capable of realizing high-efficiency near-infrared light emission under excitation of Blu-ray or red light, thereby solving the problem of low stability and low luminous efficiency of existing near-infrared light emitting materials and light emitting devices. will be.

In order to solve the above technical problem, in the near-infrared fluorescent powder of the present invention, the fluorescent powder includes an inorganic compound having the chemical formula A _x R _p O _r :D _y ,

the element A is selected from one or two of Sc, Y, La, Lu or Gd;

The R element includes Ga element, and one of Al, B, and In elements may be selectively added;

The element D includes element Cr, and one of Ce, Eu, Tb, Bi, Dy, Yb, Pr, Nd, and Er elements may be selectively added;

The parameters x, p , r and y satisfy the following conditions: 0.8≤x≤1.2, 0.8≤p≤1.2 , 2≤r≤4, and 0.0001≤y≤0.25.

Preferably, when the element A is different from the element R, it is a Ga element.

Preferably, the parameters x, p, r and y satisfy the following condition, ( x + y ): p : r =1: 1: 3:

More preferably, in the R element, the molar ratio of the Ga element to the R element is greater than or equal to 30%.

More preferably, the element A is an element Sc.

More preferably, the element D is element Cr.

The present invention further discloses a method for producing the near-infrared fluorescent powder, including the following steps.

Using a compound corresponding to the selected A, R and D elements as a raw material, and uniformly mixing in a selected chemical metering ratio; obtaining a mixture (1);

sintering the obtained mixture at 1200 to 1500° C. for 2 to 10 h in air or a protective atmosphere to obtain a roasting product; The obtained roasting product is subjected to post-treatment such as crushing, grinding, grading, and selective washing, to obtain a necessary near-infrared fluorescent powder (2).

Additionally, the compounds corresponding to the elements A, R and D include oxides, carbonates and/or nitrates.

The present invention further discloses a light emitting device, comprising a light source and a light emitting material, wherein the light emitting material includes the near-infrared fluorescent powder.

The light source is a semiconductor chip having an emission peak wavelength range of 350 to 500 nm.

The near-infrared fluorescent powder of the present invention includes an inorganic compound having a constitutional formula of A _x R _p O _r , the compound has an A _x R _p O _r structure of the grayish-titanium type as a substrate, and a selected rare earth ion or transition metal ion Through mixing, the excitation wavelength of the prepared fluorescent powder is located at 350 to 750 nm, and realizes wide or multi-spectral emission under ultraviolet light, Blu-ray or red light excitation, and the emission main peak is located at 780 to 1600 nm. By constructing a solid solution through ion substitution, etc., and due to the effect of crystal electric field splitting, it is possible to prepare near-infrared fluorescent powder materials with different emission wavelengths, and not only to improve the emission intensity of the fluorescent powder, but also to increase the controllability of the spectrum. It has been realized, and the scope of its application has been further expanded. The near-infrared fluorescent powder of the present invention promotes high-efficiency emission of mixed ions through ion co-doping, as a method of energy transfer, to further improve the emission intensity of the near-infrared fluorescent powder, and achieve more excellent application effects. there is.

The near-infrared light emitting material obtained in the present invention can be applied to the manufacture of a light emitting device, the light emitting device can emit wide near-infrared light under excitation of a Blu-ray chip, an ultraviolet chip, and through combining various fluorescent powders, the spectrum of adjustable and controllable effects. The light emitting device of the present invention can satisfy the demands of various fields such as optical fiber communication face and iris recognition, crime prevention monitor, anti-counterfeiting, laser radar, food inspection, digital medical care, 3D sensor, etc., and has a high cost and low stability, near-infrared chip It has become a new means of generating near-infrared light by preventing the negative effects of using it directly.

In order to better understand the content of the present invention, the present invention will be described in more detail with reference to specific examples and drawings of the present invention below, where:
1 is an excitation and emission spectrum diagram of a fluorescent powder sample prepared in Comparative Example 1 of the present invention, the detection wavelength of the left curve is 810 nm, and the excitation wavelength of the right curve is 460 nm.
2 is an excitation and emission spectrum diagram of the fluorescent powder sample prepared in Example 1 of the present invention, the detection wavelength of the left curve is 835 nm, and the excitation wavelength of the right curve is 460 nm.

comparative example

In the near-infrared fluorescent powder of this embodiment, the composition formula of the compound contained therein is Sc _0.98 BO ₃ :Cr _0.02 .

Formula Sc _{0 . 98} BO ₃ :According to the stoichiometric ratio of Cr _0.02 , Sc _{2 O 3} , H ₃ BO ₃ and Cr ₂ O ₃ are accurately weighed and taken and mixed uniformly to obtain a mixture; The obtained mixture is calcined in an air atmosphere at 1300° C. for 8 h, and after the temperature is lowered, a roasting product is obtained; The roasting product is post-processed such as crushing, grinding, grading, selective washing, etc. to obtain a near-infrared light emitting material sample.

The obtained near-infrared light emitting material sample was subjected to an excitation test, and excitation and emission spectral diagrams of the obtained sample are as shown in FIG. 1 . As can be seen, the emission peak of the fluorescent powder is located at 810 nm, and the relative emission intensity is 100.

Example 1

The composition formula of the near-infrared fluorescent powder of this embodiment and the compound contained therein is Sc _0.98 GaO ₃ :Cr _0.02 .

Formula Sc _{0 . 98} According to the stoichiometric ratio of _{GaO 3} :Cr _0.02 , accurately measure and take Sc ₂ O ₃ , Ga ₂ O ₃ and Cr ₂ O ₃ and mix uniformly to obtain a mixture; calcining the obtained mixture at 1400° C. for 8 h in a reducing atmosphere, and after the temperature is lowered, a roasting product is obtained; The roasted product is post-processed such as crushing, grinding, grading, and selective washing to obtain a near-infrared fluorescent powder sample.

An excitation test was performed on the obtained near-infrared light emitting material sample, and excitation and emission spectrum diagrams of the obtained sample are as shown in FIG. 2 . As can be seen, the emission peak of the fluorescent powder is 835 nm, and the relative emission intensity is 130.

Example 2

The composition formula of the near-infrared fluorescent powder of this embodiment and the compound included therein is Sc _0.98 Ga _0.3 B _0.7 O ₃ :Cr _0.02 .

Formula Sc _{0 . 98} Ga _{0 . 3} B _{0 .} According to the chemical metering ratio of _{7 O 3} :Cr _0.02 , Sc ₂ O ₃ , Ga ₂ O ₃ and Cr ₂ O ₃ are accurately weighed and taken and mixed uniformly; calcining the obtained mixture at 1400° C. for 8 h in a reducing atmosphere to obtain a roasting product after the temperature is lowered; The roasted product is post-processed such as crushing, grinding, grading, and selective washing to obtain a near-infrared fluorescent powder sample. Through the measurement, the emission peak of the fluorescent powder is 826 nm, and the relative emission intensity is 150.

Examples 3 to 26

Examples 3 to 26 As for the near-infrared fluorescent powder and the light-emitting device containing the fluorescent powder, the chemical formulas of the compounds are listed in Table 1, respectively. , only by selecting, mixing, grinding, and roasting an appropriate amount of a compound according to the chemical composition of the target compound in each example, to obtain a necessary near-infrared light emitting material.

When the performance of the light emitting material prepared in each Example was detected, the test results are shown in Table 1.

Examples and Comparative Examples Molecular formula and luminescence performance, excitation wavelength is 460 nm number molecular formula Peak position (nm) Relative luminous intensity comparative example Sc _{0 . 98} BO ₃ :Cr _{0 .02} 810 100 Example 1 Sc _{0 . 98 GaO 3} :Cr _0.02 835 130 Example 2 Sc _0.98 Ga _0.3 B _0.7 O ₃ :Cr _0.02 826 150 Example 3 Sc _0.95 Ga _0.3 B _0.7 O ₃ :Cr _0.02, Pr _0.03 844 218 Example 4 Y _0.98 Ga _0.6 B _0.4 O ₃ :Cr _0.02 831 141 Example 5 La _0.98 Ga _0.3 B _0.7 O ₃ :Cr _0.02 823 138 Example 6 Lu _0.96 Ga _0.8 B _0.2 O ₃ :Cr _0.04 827 142 Example 7 Gd _0.96 Ga _0.8 B _0.2 O ₃ :Cr _0.04 827 139 Example 8 Sc _0.97 Ga _0.6 Al _0.4 O ₃ :Cr _0.03 843 185 Example 9 Sc _0.97 Ga _0.6 In _0.4 O ₃ :Cr _0.03 837 162 Example 10 Sc _0.75 Ga _0.3 B _0.7 O _2.7 :Cr _0.05 845 176 Example 11 Sc _1.15 Ga _0.7 Al _0.1 O _2.97 :Cr _0.03 830 149 Example 12 Sc _1.2 Ga _0.7 B _0.35 O _3.42 :Cr _0.03 839 155 Example 13 Sc _0.85 Ga _0.7 B _0.5 O _3.12 :Cr _0.03 842 162 Example 14 Sc _0.97 Ga _0.9 B _0.1 O _3.33 :Cr _0.25 837 158 Example 15 Sc _0.97 Ga _0.3 B _0.7 O _2.96 :Cr _0.0001 843 129 Example 16 Sc _0.8 Ga _0.4 B _0.4 O _2.415 :Cr _0.01 829 166 Example 17 Sc _0.7 Y _0.2 Ga _0.7 B _0.3 O _2.865 :Cr _0.01 827 145 Example 18 Sc _1.2 Ga _0.6 B _0.6 O ₄ :Cr _0.25 845 168 Example 19 Sc _0.97 Ga _0.6 B _0.5 O _3.18 :Cr _0.03, Ce _0.02 840 200 Example 20 Sc _0.97 Ga _0.6 B _0.5 O _3.18 :Cr _0.03, Eu _0.02 829 205 Example 21 Sc _0.97 Ga _0.6 B _0.5 O _3.18 :Cr _0.03, Tb _0.02 826 191 Example 22 Sc _0.95 Ga _0.5 B _0.5 O ₃ :Cr _0.03, Bi _0.02 825 177 Example 23 Sc _0.95 Ga _0.5 B _0.5 O ₃ :Cr _0.03, Dy _0.02 831 176 Example 24 Sc _0.95 Ga _0.5 B _0.5 O ₃ :Cr _0.03, Yb _0.02 970, 1026 215 (1026 nm) Example 25 Sc _0.95 Ga _0.5 B _0.5 O ₃ :Cr _0.03, Nd _0.02 944, 1063,1075 221 (1063 nm) Example 26 Sc _0.95 Ga _0.5 B _0.5 O ₃ :Cr _0.03, Er _0.02 1538,1557 205 (1538 nm)

It is clear that the above examples are only for clearly explaining the enumerated examples, and do not limit the examples. A person skilled in the art can proceed with other different types of changes or variations on the basis of the above description. It is not necessary to enumerate all examples here. Obvious changes or variations derived therefrom still fall within the protection scope of the present invention.

Claims (10)

In the near-infrared fluorescent powder,
The fluorescent powder includes an inorganic compound whose chemical formula is AxRpOr:Dy,
The compound has an A _x R _p O _r structure of the gray titanite type as a substrate,
Among them, the A element is selected from one or two of Sc, Y, La, Lu and Gd elements;
The R element includes Ga element, and one of Al, B, and In elements may be selectively added;
Among them, the molar ratio of the Ga element to the R element is greater than or equal to 30%;
The element D includes element Cr, and one of Ce, Eu, Tb, Bi, Dy, Yb, Pr, Nd, and Er elements may be selectively added;
wherein the parameters x, p, r and y satisfy the following conditions, and 0.8≤x≤1.2, 0.8≤p≤1.2, 2≤r≤4, 0.0001≤y≤0.25.
The method of claim 1,
The parameters x, p, r and y satisfy the following conditions, and ( x + y ): p : r =1: 1: 3, wherein the near-infrared fluorescent powder.
3. The method of claim 1 or 2,
The element A is a near-infrared fluorescent powder, characterized in that the element Sc.
3. The method of claim 1 or 2,
The near-infrared fluorescent powder, characterized in that the element D is element Cr.
Using a compound corresponding to the selected A, R and D elements as a raw material, and uniformly mixing in a selected chemical metering ratio; obtaining a mixture (1);
sintering the obtained mixture at 1200 to 1500° C. for 2 to 10 h in air or a protective atmosphere to obtain a roasting product; The obtained roasting product is subjected to crushing, grinding, grading, and selective washing and post-treatment to obtain a necessary near-infrared fluorescent powder (2); The method for producing a near-infrared fluorescent powder according to claim 1 or 2, characterized in that it comprises a.
6. The method of claim 5,
The compound corresponding to the elements A, R and D includes an oxide, carbonate and/or nitrate.
A light emitting device comprising a light source and a light emitting material, the light emitting device comprising:
The light emitting material is a light emitting device comprising the near-infrared fluorescent powder according to claim 1 or 2.
8. The method of claim 7,
The light source is a light emitting device, characterized in that the emission peak wavelength range is a semiconductor chip of 350 to 500nm.
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