Ultraviolet-excited blue-violet fluorescent powder and LED white light device

Abstract

The invention relates to the technical field of fluorescent powder and LED white light devices, in particular to ultraviolet-excited blue-violet fluorescent powder and an LED white light device, the fluorescent powder is an inorganic compound with the molecular formula of Li5Am-xSrLnB12O24: xBi < 3 + >, the element A is one or more of Mg and Zn, and the element B is one or more of Mg and Zn; the element L is one or more of Al, Ga and In; 0.9 < = m < = 1.1, 0.9 < = n < = 1.1, and 0 < x < = 0.2. According to the ultraviolet-excited blue-violet fluorescent powder and the LED white light device, compared with the prior art, the fluorescent powder provided by the invention is higher in luminous intensity, from embodiment data, when the doping concentration of Bi is 0.05 (for example, Li5Mg0. 95SrAlB12O24: 0.05 Bi < 3 + > in an embodiment 5), the relative luminous intensity reaches 100, while the relative luminous intensity of Sr2B5O9Cl: Eu < 2 + > in a contrast ratio 1 is only 81, and meanwhile, the relative luminous intensity of Sr2B5O9Cl: Eu < 2 + > in a contrast ratio 1 is not less than 81. The peak wavelength of the emission spectrum of the fluorescent powder is adjustable, and the peak wavelength can be accurately adjusted to 400-430nm by doping different elements and controlling the content of the elements, so that the deficiency of the existing blue fluorescent powder in the wave band is effectively made up, and the requirements of a full-spectrum white light LED (Light Emitting Diode) are met.

Description

Technical Field

[0001] The present invention relates to the technical field of fluorescent powder and LED white light devices, in particular to ultraviolet-excited blue-violet fluorescent powder and LED white light devices. Background Art

[0002] In recent years, high-efficiency, high-color-rendering blue light full-spectrum LED lighting technology has developed rapidly, but it has obvious shortcomings compared to the sunlight spectrum. On the one hand, the short-wave blue light in the spectrum is seriously missing, and long-term use may have an impact on human physiology. On the other hand, when the color temperature is greater than 5000K, there is a risk of "blue light leakage". In the European and American markets, which have strict requirements on light quality, consumers prefer near-natural light sources. The purple full-spectrum LED white light lighting products launched by Seoul Semiconductor in South Korea can effectively solve some of the problems of blue full-spectrum LEDs, making purple full-spectrum LED lighting one of the important directions for the healthy development of the LED lighting industry. In addition, at this stage, the ultraviolet / near-ultraviolet excited phosphor system has more yellow, green, and red phosphors, while blue phosphors are relatively scarce. The emission spectrum of existing blue phosphors is mainly located at 450nm, and is seriously lacking in the 400-430nm range compared to the sunlight spectrum, which cannot meet the demand of full-spectrum white light LEDs for short-wave blue-violet light. Summary of the Invention

[0003] (1) Technical problems solved In view of the deficiencies of the prior art, the present invention provides ultraviolet-excited blue-violet phosphors and LED white light devices.

[0004] (2) Technical solution To achieve the above object, the present invention provides the following technical solutions: ultraviolet excited blue-violet light phosphor and LED white light device, including phosphor with molecular formula Li5A m-x SrL n B 12 O 24 :xBi 3+ An inorganic compound, wherein the element A is one or more of Mg and Zn; the element L is one or more of Al, Ga, and In; and 0.9≤m≤1.1, 0.9≤n≤1.1, and 0<x≤0.2.

[0005] The present invention has the following improvements: m=1, n=1, and x=0.05.

[0006] The present invention has the following improvements: A is Mg, and L is Al.

[0007] The present invention has the following improvements: the matrix composition is regulated by introducing Zn, Ga and In elements, thereby regulating the crystal field environment around Bi, so that the peak wavelength of the emission spectrum is adjustable within the range of 400-430 nm.

[0008] The present invention is improved in that the peak wavelength range of the chip is 350-370nm, and the white light LED device comprises the phosphor according to any one of claims 1-3 and the blue phosphor BaMgAl 10 O 17 :Eu 2+ 、Green phosphor (Ca, Sr) 2SiO 4: Eu 2+ and red phosphor (Ca, Sr)AlSiN3:Eu 2+ .

[0009] The present invention further provides an ultraviolet-excited blue-violet phosphor and an LED white light device, comprising the above-mentioned ultraviolet-excited blue-violet phosphor and the LED white light device, and comprising the following steps: Step 1: According to the chemical formula Li5A m-x SrL n B 12 O 24 :xBi 3+ The oxides, carbonates or borates of the corresponding elements are accurately weighed in a stoichiometric ratio as raw materials, and the purity of the raw materials is not less than 99.9%; Step 2: Place the weighed raw materials into a grinder and grind for 20 minutes to ensure that the raw materials are fully mixed; Step 3: The mixed raw materials were transferred into an alumina crucible, placed in a high-temperature tube furnace, and sintered at 650° C. for 7 h in a nitrogen sintering atmosphere; Step 4: Cooling the calcined product to room temperature in the furnace, crushing and grinding the calcined product to obtain the luminescent material.

[0010] (3) Beneficial effects Compared with the prior art, the present invention provides ultraviolet-excited blue-violet phosphors and LED white light devices, which have the following beneficial effects: The ultraviolet excited blue-violet phosphor and LED white light device are configured to provide a higher luminous intensity of the phosphor than the prior art. According to the data of the embodiment, when the Bi³⁺ doping concentration is 0.05 (such as Li5Mg in Example 5), 0.95 SrAlB 12 O 24 :0.05Bi 3+ ), the relative luminous intensity reaches 100, while in Comparative Example 1, Sr2B5O9Cl:Eu 2+ The relative luminous intensity is only 81. At the same time, the peak wavelength of the emission spectrum of the phosphor of the present invention is adjustable. By doping different elements and controlling their content, the peak wavelength can be accurately adjusted to 400-430nm, effectively making up for the lack of existing blue phosphors in this band and meeting the needs of full-spectrum white light LEDs.

[0011] The ultraviolet excited blue-violet fluorescent powder and LED white light device are provided by setting the Li5MgSrAlB 12 O 24 As a new luminescent matrix material, it expands the selection range of phosphor matrix materials. The matrix material has a stable crystal structure, providing a good foundation for the high-performance luminescence of the phosphor, and is expected to promote the development of the ultraviolet / near-ultraviolet excited phosphor field.

[0012] The ultraviolet-excited blue-violet phosphor and LED white light device can be widely used in indoor lighting, outdoor lighting, display screen backlight sources, automotive lighting and other fields through the blue-violet phosphor and LED white light device containing the phosphor of the present invention. In indoor lighting, they can provide comfortable light close to natural light to protect eyesight. In display screen backlight applications, they can enhance the authenticity and vividness of displayed colors. In the field of automotive lighting, they help improve lighting effects and ensure driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0014] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0015] See also Figure 1 , a UV-excited blue-violet phosphor and LED white light device, including phosphor with molecular formula Li5A m-x SrL n B 12 O 24 :xBi 3+ An inorganic compound, wherein the element A is one or more of Mg and Zn, the element L is one or more of Al, Ga, and In, and the parameters m, n, and x satisfy: 0.9≤m≤1.1, 0.9≤n≤1.1, and 0<x≤0.2.

[0016] The raw materials are mainly oxides, carbonates, borates, etc. of the corresponding elements, and the purity of the raw materials is required to be no less than 99.9%. For example, the synthesis of Li5A m-x SrL n B 12 O 24 :xBi 3+When making phosphors, raw materials such as Li2CO3, H3BO3, MgO, Al2O3, SrCO3, and Bi2O3 are used.

[0017] The raw materials were accurately weighed according to the stoichiometric ratio of the chemical formula, placed in a grinder and ground for 20 minutes to ensure that the raw materials were fully mixed. The mixed raw materials were then transferred into an alumina crucible and placed in a high-temperature tube furnace. They were sintered at 650°C for 7 hours in a nitrogen sintering atmosphere, and then cooled to room temperature with the furnace. Finally, the calcined product was crushed and ground to obtain a luminescent material with good morphology.

[0018] In this embodiment, m=1, n=1, and x=0.05.

[0019] In this embodiment, A is Mg, L is Al, and Li5A m-x SrL n B 12 O 24 :xBi 3+ system, this is because the pure matrix Li5MgSrAlB 12 O 24 The crystal structure has good symmetry and high stability. The phosphor based on this matrix has strong luminous intensity. When combined with the blue phosphor BaMgAl 10 O 17 :Eu 2+ 、Green phosphor (Ca, Sr) 2SiO 4: Eu 2+ and red phosphor (Ca, Sr)AlSiN3:Eu 2+ When combined with UV / near-UV chip LEDs, it can produce white light with high luminous efficiency, strong spectral continuity, high color rendering index and low color temperature. In this embodiment, the matrix composition is regulated by introducing Zn, Ga, and In elements, thereby regulating the crystal field environment around Bi, so that the peak wavelength of the emission spectrum is adjustable in the range of 400-430nm. m-x SrL n B 12 O 24 :xBi 3+By introducing a certain proportion of Zn, Ga, In and other elements of the same family or with similar ionic radius and the same valence state into the matrix, the matrix composition can be controlled, and then the crystal field environment around Bi can be controlled to achieve controllable adjustment of the peak wavelength of the emission spectrum, and its peak wavelength range is 400-430nm. Taking Zn doping as an example, when Zn with a small ionic radius replaces part of Mg, the volume of the polyhedron occupied by the cationic Mg decreases and shrinks, and the volume of the polyhedron occupied by Bi also decreases, the covalent bond length decreases, the symmetry of the crystal structure decreases, the lattice distortion increases, and the Bi ion energy level splitting increases, resulting in a red shift in the spectrum. Similarly, when Ga or In with a large ionic radius replaces Al, the polyhedron connected to the polyhedron occupied by Bi expands, which reduces the volume of the polyhedron occupied by Bi, and also causes the spectrum to red shift.

[0020] In this embodiment, the peak wavelength range of the chip is 350-370nm, and the white light LED device comprises the phosphor according to any one of claims 1 to 3, and the blue phosphor BaMgAl 10 O 17 :Eu 2+ 、Green phosphor (Ca, Sr) 2SiO 4: Eu 2+ and red phosphor (Ca, Sr)AlSiN3:Eu 2+ , to achieve full-spectrum white light emission.

[0021] The present invention further provides an ultraviolet-excited blue-violet phosphor and an LED white light device, comprising the above-mentioned ultraviolet-excited blue-violet phosphor and the LED white light device, and comprising the following steps: Step 1: According to the chemical formula Li5A m-x SrL n B 12 O 24 :xBi 3+ The oxides, carbonates or borates of the corresponding elements are accurately weighed in a stoichiometric ratio as raw materials, and the purity of the raw materials is not less than 99.9%; Step 2: Place the weighed raw materials into a grinder and grind for 20 minutes to ensure that the raw materials are fully mixed; Step 3: The mixed raw materials were transferred into an alumina crucible, placed in a high-temperature tube furnace, and sintered at 650° C. for 7 h in a nitrogen sintering atmosphere; Step 4: Cooling the calcined product to room temperature in the furnace, crushing and grinding the calcined product to obtain the luminescent material.

[0022] Example 1: Preparation of Li5Mg 0.99 SrAlB 12 O 24 :0.01Bi 3+Phosphor powder, accurately weigh the raw materials of Li2CO3, H3BO3, ZnO, MgO, Al2O3, SrCO3, and Bi2O3, place them in a grinder and grind them for 20 minutes, transfer the ground raw materials to an alumina crucible, put them into a high-temperature tube furnace, sinter them at 650°C for 7 hours under a nitrogen atmosphere, cool them to room temperature with the furnace, and then crush and grind the products to obtain a luminescent material with good morphology. After testing, its relative luminescence intensity is 62, the color rendering index is 96.0, and the peak wavelength is 410nm.

[0023] Example 2-7: Example 2 (Li5Mg 0.98 SrAlB 12 O 24 :0.02Bi 3+ ) as an example, accurately weigh Li2CO3, H3BO3, ZnO, MgO, Al2O3, SrCO3, and Bi2O3 raw materials, and repeat the grinding, sintering, cooling, crushing, and grinding steps of Example 1. The only difference between the examples is the Bi³⁺ doping concentration, while the other conditions are the same. For specific parameters, see Figure 1 .

[0024] Example 8: Preparation of Li5Mg 0.93 Zn 0.02 SrAlB 12 O 24 :0.05Bi 3+ Phosphor, accurately weigh Li2CO3, H3BO3, ZnO, MgO, Al2O3, SrCO3, Bi2O3 raw materials according to the stoichiometric ratio, and the subsequent operations are the same as those in Example 1. In this embodiment, due to the doping of Zn, the luminescence spectrum is red-shifted and the luminescence intensity is improved. The relative luminous intensity is 98, the color rendering index is 97.0, and the peak wavelength is 410nm.

[0025] Example 9-13: Example 9 (Li5Mg 0.91 Zn 0.04 SrAlB 12 O 24 :0.05Bi 3+ ) as an example, the content of Zn doped in Mg was changed, the corresponding raw materials were accurately weighed, and the phosphor was prepared according to the same process. The parameters of each embodiment are shown in FIG. Figure 1 .

[0026] Example 14: Preparation of Li5Mg 0.95 SrAl 0.98 Ga 0.02 B 12 O 24 :0.05Bi 3+Phosphor powder, accurately weighing raw materials such as Li2CO3, H3BO3, ZnO, MgO, Al2O3, SrCO3, Bi2O3, etc., and obtaining the product through steps such as grinding and sintering. In this embodiment, Ga is doped at the Al position to achieve spectral regulation, with a relative luminous intensity of 97, a color rendering index of 97.0, and a peak wavelength of 414nm.

[0027] Example 15-20: Example 15 (Li5Mg 0.95 SrAl 0.96 Ga 0.04 B 12 O 24 :0.05Bi 3+ ) as an example, the content of Ga or In doped in Al position was changed, and the above preparation process was repeated. The parameters of each embodiment are shown in FIG. Figure 1 .

[0028] Comparative Example 1: Preparation of Sr 2 B5O9Cl:Eu 2+ Blue-violet phosphor, SrCO3, H3BO3, SrCl2, Eu2O3 raw materials are accurately weighed according to the stoichiometric ratio, placed in a grinder and ground for 20 minutes, the raw materials are transferred to an alumina crucible, placed in a high-temperature tube furnace, and sintered at 800°C for 6 hours in a reducing atmosphere of a mixed gas of 5% H2 and 95% N2. After cooling to room temperature with the furnace, the product is crushed and ground to obtain a luminescent material with relatively uniform particle size, with a relative luminous intensity of 81, a color rendering index of 95, and a peak wavelength of 420nm. Compared with the embodiments of the present invention, there are deficiencies in luminous intensity and spectral adjustment flexibility.

[0029] References to "embodiments" herein mean that the specific features, structures, or characteristics described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the word "embodiment" in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or relevance to other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the various technical features mentioned in the embodiments can be combined in any manner to form a corresponding implementable technical solution.

[0030] Unless otherwise defined, the technical terms used herein have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms herein is only for describing specific embodiments and is not intended to limit this application.

[0031] While the embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that various changes, modifications, substitutions, and alterations can be made to the embodiments without departing from the principles and spirit of the invention.

Claims

1. A UV-excited blue-violet phosphor and a LED white light device, characterized by: The phosphor has the molecular formula Li5A m-x SrL n B 12 O 24 :xBi 3+ An inorganic compound, wherein the element A is one or more of Mg and Zn; the element L is one or more of Al, Ga, and In; and 0.9≤m≤1.1, 0.9≤n≤1.1, and 0<x≤0.

2.

2. The ultraviolet-excited blue-violet phosphor and LED white light device according to claim 1, characterized in that: Said m=1, n=1, x=0.

05.

3. The ultraviolet-excited blue-violet phosphor and LED white light device according to claim 1, characterized in that: A is Mg, and L is Al.

4. The ultraviolet-excited blue-violet phosphor and LED white light device according to claim 1, characterized in that: The matrix composition is regulated by introducing Zn, Ga and In elements, thereby regulating the crystal field environment around Bi, so that the peak wavelength of the emission spectrum is adjustable within the range of 400-430 nm.

5. The ultraviolet-excited blue-violet phosphor and LED white light device according to claim 1, characterized in that: The chip has a peak wavelength range of 350-370 nm, and the white light LED device comprises the phosphor according to any one of claims 1 to 3, and the blue phosphor BaMgAl 10 O 17 :Eu 2+ 、Green phosphor (Ca, Sr) 2SiO 4: Eu 2+ and red phosphor (Ca, Sr)AlSiN3:Eu 2+ .

6. A UV-excited blue-violet phosphor and an LED white light device, comprising the UV-excited blue-violet phosphor and the LED white light device according to any one of claims 1 to 9, characterized in that: The steps include: Step 1: According to the chemical formula Li5A m-x SrL n B 12 O 24 :xBi 3+ The oxides, carbonates or borates of the corresponding elements are accurately weighed in a stoichiometric ratio as raw materials, and the purity of the raw materials is not less than 99.9%; Step 2: Place the weighed raw materials into a grinder and grind for 20 minutes to ensure that the raw materials are fully mixed; Step 3: The mixed raw materials were transferred into an alumina crucible, placed in a high-temperature tube furnace, and sintered at 650° C. for 7 h in a nitrogen sintering atmosphere; Step 4: Cooling the calcined product to room temperature in the furnace, crushing and grinding the calcined product to obtain the luminescent material.

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