Red light fluorescent ceramic, method for manufacturing the same, and light source device

Abstract

This application belongs to the field of light source technology and provides a red fluorescent ceramic, comprising: a fluoride ceramic matrix and first fluorescent particles, second fluorescent particles, and third fluorescent particles distributed within the fluoride ceramic matrix. The first fluorescent particle has a first emission peak, the second fluorescent particle has a second emission peak, and the third fluorescent particle has a third emission peak. The red fluorescent ceramic has an emission wavelength range of 600nm-680nm; wherein the first, second, and third emission peaks are all located within the emission wavelength range and do not overlap with each other. This red fluorescent ceramic can achieve red light emission with high color purity, has high fluorescence conversion efficiency and high thermal conductivity, improves the display color gamut, and is expected to further reduce the cost of laser display light sources. In addition, embodiments of this application also provide a method for preparing the red fluorescent ceramic and a light source device.

Description

Technical Field

[0001] This application relates to the field of light source technology, specifically to a red fluorescent ceramic, its preparation method, and a light source device. Background Technology

[0002] Laser light sources, due to their advantages such as high brightness, long illumination distance, higher conversion efficiency, and longer lifespan, are currently widely used in many important fields such as automotive headlights, outdoor lighting, laser TVs, and laser cinemas, and may soon replace current LED lighting on a large scale. Currently, commonly used fluorescent materials for high-power LEDs and laser light sources include fluorescent ceramics, fluorescent glasses, fluorescent thin films, fluorescent single crystals, and quantum wells. Among these, fluorescent ceramics, due to their excellent quantum efficiency, high light extraction efficiency, high thermal conductivity and thermal stability, and easily tunable microstructure, have become the best-performing and most promising fluorescent conversion material for laser lighting.

[0003] Currently, there are two main types of commercially available red fluorescent materials that can be excited by blue light: one is based on CaAlSiN3:Eu 2+ One type is the nitride red powder represented by K2SiF6:Mn. 4+ Fluoride red phosphors are a prime example. Nitride red phosphors, when encapsulated with inorganic adhesives, cannot maintain high luminous efficiency and must be encapsulated with silicone rubber, making them unsuitable for continuous blue laser excitation. Fluoride red phosphors, due to their long fluorescence lifetime, are prone to photo-thermal saturation under laser excitation, leading to a sharp drop in fluorescence conversion efficiency. Neither of these methods meets current application requirements. Summary of the Invention

[0004] This application provides a red fluorescent ceramic, its preparation method, and a light source device to at least partially improve the above-mentioned technical problems.

[0005] In a first aspect, embodiments of this application provide a red fluorescent ceramic, comprising: a fluoride ceramic matrix and a first fluorescent particle, a second fluorescent particle, and a third fluorescent particle distributed within the fluoride ceramic matrix, wherein the first fluorescent particle has a first emission peak, the second fluorescent particle has a second emission peak, and the third fluorescent particle has a third emission peak.

[0006] The red fluorescent ceramic has an emission wavelength range of 600nm-680nm; wherein the first emission peak, the second emission peak and the third emission peak are all located within the emission wavelength range and do not overlap with each other.

[0007] In some embodiments, the first fluorescent particle has a first emission wavelength, the second fluorescent particle has a second emission wavelength, and the third fluorescent particle has a third emission wavelength; wherein any two of the first emission wavelength, the second emission wavelength, and the third emission wavelength at least partially overlap, that is, adjacent portions of any two of the first emission wavelength, the second emission wavelength, and the third emission wavelength overlap, thereby forming a continuous emission wavelength range.

[0008] In some embodiments, the first emission wavelength is 600nm-650nm; the second emission wavelength is 630nm-680nm; and the third emission wavelength is 600nm-650nm.

[0009] In some implementations, the first emission peak is located at 610nm-620nm; the second emission peak is located at 650nm-670nm; and the third emission peak is located at 630nm-640nm.

[0010] In some embodiments, the first emission peak is located near 620 nm, that is, the first emission peak can be 620 nm or (620±a) nm; the second emission peak is located near 650 nm, that is, the second emission peak can be 650 nm or (650±a) nm; the third emission peak is located near 630 nm, that is, the third emission peak can be 630 nm or (630±a) nm, where a can be, for example, 0.1-3 nm, and this embodiment does not limit it.

[0011] In some embodiments, the first fluorescent particle is CaAlSiN3:Eu 2+ The phosphor and the secondary fluorescent particles are selected from (Ca,Sr)AlSiN3:Eu 2+ Phosphor, (Ca,Ba)AlSiN3:Eu 2+ Phosphor, (Ca,Sr,Ba)AlSiN3:Eu 2+ At least one of the phosphors, wherein the third fluorescent particle is K2SiF6:Mn 4+ Fluorescent powder.

[0012] In some embodiments, the volume content of the first fluorescent particle is 32%-40%, the volume content of the second fluorescent particle is 8%-10%, the volume content of the third fluorescent particle is 10%-30%, and the volume content of the fluoride ceramic matrix is ​​20%-50%.

[0013] In some embodiments, the fluoride ceramic matrix includes calcium fluoride, and the fluoride ceramic matrix also includes at least one of magnesium fluoride, strontium fluoride, and barium fluoride.

[0014] In some embodiments, the diameter of the first fluorescent particle is 8-16 μm, the diameter of the second fluorescent particle is 18-22 μm, and the diameter of the third fluorescent particle is 23-30 μm.

[0015] In some embodiments, the first fluorescent particle, the second fluorescent particle, and the third fluorescent particle are configured in at least two of the following shapes: rod-shaped, spherical, and polyhedral.

[0016] Secondly, embodiments of this application also provide a light source device, including a light source and a wavelength conversion device, wherein the wavelength conversion device includes the aforementioned red fluorescent ceramic.

[0017] Thirdly, the embodiments of this application also provide a method for preparing the above-mentioned red fluorescent ceramic, including: mixing fluoride powder with first fluorescent particles, second fluorescent particles and third fluorescent particles, dispersing in an organic solvent, ball milling and adding sintering aid to mix to obtain ceramic powder, sintering the ceramic powder to obtain composite ceramic, and annealing to form red fluorescent ceramic.

[0018] The red fluorescent ceramic, its preparation method, and the light source device provided in this application embodiment can achieve red light emission with high color purity, while also having high fluorescence conversion efficiency and high thermal conductivity. It is expected to obtain a broad-spectrum red fluorescent material, providing a solution for realizing a high color purity red light source, improving the display color gamut, and potentially further reducing the cost of laser display light sources. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a red fluorescent ceramic according to an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of the structure of a light source device proposed in an embodiment of this application. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without inventive effort are within the scope of protection of the present application.

[0023] In this application, unless otherwise expressly specified or limited, the terms "installation," "connection," "fixation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components; they can refer to mere surface contact; or they can refer to surface contact connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] Furthermore, the terms "first," "second," etc., are used only for distinguishing descriptions and should not be construed as referring to specific or particular structures. The terms "some embodiments," "other embodiments," 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 this application. In this application, 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 can be combined in a suitable manner in any 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 application, as well as the features of different embodiments or examples.

[0025] like Figure 1 As shown, this application provides a red fluorescent ceramic 10, including: a fluoride ceramic matrix 100 and a first fluorescent particle 201, a second fluorescent particle 301 and a third fluorescent particle 401 distributed in the fluoride ceramic matrix 100. The first fluorescent particle 201, the second fluorescent particle 301 and the third fluorescent particle 401 are uniformly distributed in the fluoride ceramic matrix 100.

[0026] The fluoride ceramic matrix 100 is mainly composed of fluorides, which typically have high melting points, boiling points, and decomposition temperatures. Therefore, the fluoride ceramic matrix 100 generally exhibits excellent thermal and chemical stability. Furthermore, the fluoride ceramic matrix 100 also possesses high ion conductivity, a wide operating temperature range, and low polarization loss. The fluorides can be calcium fluoride (CaF2), barium fluoride (BaF2), magnesium fluoride (MgF2), and strontium fluoride (SrF2), among others.

[0027] In some embodiments, the volume content of the fluoride ceramic matrix 100 can be 20%-50%, for example, 20%-30%, 30%-40%, 40%-50%, 30%-50%, etc. A suitable volume content ensures both good transmittance of the entire red fluorescent ceramic 10 and the conversion efficiency of the fluorescent particles.

[0028] In some embodiments, the fluoride ceramic matrix 100 may include calcium fluoride, and the fluoride ceramic matrix 100 may also include at least one of magnesium fluoride, strontium fluoride, and barium fluoride. That is, the fluoride ceramic matrix 100 may include a mixture of calcium fluoride and at least one other fluoride. This is merely an example. Figure 1 In the illustrated embodiment, the fluoride ceramic matrix 100 includes calcium fluoride 101 and magnesium fluoride 102.

[0029] Calcium fluoride exhibits low absorption coefficients in the ultraviolet and visible light bands, which helps reduce light loss during transmission and improves the efficiency of optical systems. Simultaneously, calcium fluoride remains stable at high temperatures, resisting decomposition or phase transitions, which helps maintain the performance stability of ceramics under high-temperature conditions, ensuring the stability of red-light ceramic materials during long-term use. In some embodiments, the volume percentage of calcium fluoride in the fluoride ceramic matrix 100 can be, for example, 60%-95%, 70%-90%, 60%-80%, etc.

[0030] Using calcium fluoride-based ceramics as the matrix enables the low-temperature sintering preparation of red composite fluorescent ceramics, avoiding carbon contamination introduced by high-temperature sintering. This also ensures high luminous efficiency and morphological structure of the phosphor particles, facilitating high fluorescence conversion efficiency. Furthermore, using fluoride as the matrix material promotes better heat dissipation during the luminescence process, maintaining stable luminous efficiency. This breakthrough overcomes the technical challenges in the preparation of red fluorescent ceramics, meeting the requirements of high-power LEDs and laser light sources, and providing a solution for achieving high-color-purity red light sources.

[0031] Red fluorescent ceramics have an emission wavelength range of 600nm-680nm. The first fluorescent particle has a first emission peak, the second fluorescent particle has a second emission peak, and the third fluorescent particle has a third emission peak. The first, second, and third emission peaks are all located within the emission wavelength range and do not overlap with each other. That is, the first, second, and third fluorescent particles have different emission peaks, which are located within the emission wavelength range of 600nm-680nm.

[0032] The first fluorescent particle has a first emission wavelength, the second fluorescent particle has a second emission wavelength, and the third fluorescent particle has a third emission wavelength; the first, second, and third emission wavelengths can all be a portion of the range of 600nm-680nm. Any two of the first, second, and third emission wavelengths may have adjacent overlaps, meaning that the emission wavelengths of the first, second, and third fluorescent particles can be partially the same, or their emission wavelengths may partially overlap. This embodiment does not impose any limitations on this.

[0033] In one embodiment, the first fluorescent particle 201 can be CaAlSiN3:Eu 2+ Phosphor, CaAlSiN3:Eu 2+ The phosphor is a high-performance nitride phosphor. CaAlSiN3 has a stable crystal structure, providing a favorable luminescent environment for Eu2+ ions. CaAlSiN3:Eu 2+ The first emission wavelength range of the phosphor can be 600-650nm, and the first emission peak can be located at 610nm-620nm. Furthermore, the first emission peak can be located approximately around 620nm.

[0034] The particle size of the first fluorescent particle 201 can be controlled within the range of 8-16 μm, and the particle morphology can be, for example, long rod-shaped. The volume content of the first fluorescent particle 201 can be 32%-40%, for example, 32%-35% or 35%-40%. Within this volume percentage range, the distribution density of the first fluorescent particle 201 in the fluoride ceramic matrix 100 is relatively moderate, and it can cooperate with the second fluorescent particle 301 and the third fluorescent particle 401 to achieve higher red light conversion efficiency.

[0035] The second fluorescent particle 301 is selected from (Ca,Sr)AlSiN3:Eu 2+ Phosphor, (Ca,Ba)AlSiN3:Eu 2+ Phosphor, (Ca,Sr,Ba)AlSiN3:Eu 2+ At least one of the phosphors. (Ca,Sr)AlSiN3:Eu2+ Phosphor is an important nitride phosphor with an orthorhombic CaAlSiN3 crystal structure and no impurity phases. Its emission wavelength is in the red light range of 615 nm to 640 nm, making it an effective red component in the spectrum for the fabrication of high color rendering white LED light sources. This phosphor exhibits high fluorescence intensity and emission time, along with good heat resistance, moisture resistance, and light resistance.

[0036] (Ca,Ba)AlSiN3:Eu 2+ Phosphor is a high-performance fluorescent material that uses Eu to... 2+ This phosphor is prepared by ion doping into a (Ca,Ba)AlSiN3 matrix. It possesses advantages such as high quantum efficiency, rich spectral density, and good thermal stability. (Ca,Sr,Ba)AlSiN3:Eu 2+ Phosphor is an important nitride phosphor, among which Eu 2+ As activator ions, they are doped into the matrix (Ca, Sr, Ba)AlSiN3. This matrix structure is stable and can provide Eu... 2+ Ions provide a favorable crystal field environment, thereby enabling them to exhibit excellent luminescence properties.

[0037] The second emission wavelength range of the second fluorescent particle 301 can be 630-680 nm, and the second emission peak can be located at 650 nm-670 nm. Further, the second emission peak can be located near 650 nm. The particle size of the second fluorescent particle 301 can be controlled between 18-22 μm, and the particle morphology can be, for example, spherical. The volume content of the second fluorescent particle 301 can be 8%-10%, for example, 9%-10% or 8%-9%. Within this volume percentage range, the distribution density of the second fluorescent particle 301 in the fluoride ceramic matrix 100 is relatively moderate, and it can cooperate with the first fluorescent particle 201 and the third fluorescent particle 401 to achieve higher red light conversion efficiency.

[0038] The third fluorescent particle, 401, is K2SiF6:Mn. 4+ Phosphor, K2SiF6:Mn 4+ Phosphors are composed of elements such as potassium (K), silicon (Si), fluorine (F), and manganese (Mn), among which Mn... 4+ As the luminescent center, the third fluorescent particle 401 has a third emission wavelength range of 600-650 nm. In a preferred embodiment, any two of the first, second, and third emission wavelengths at least partially overlap, so that the emission wavelength range of the entire red fluorescent ceramic can completely cover the 600 nm-680 nm range.

[0039] The third emission peak of the third fluorescent particle 401 can be located in the 630nm-640nm range. More specifically, the third emission peak can be located near 630nm. The particle size of the third fluorescent particle 401 can be controlled within 23-30μm, and the particle morphology can be, for example, polyhedral. The volume fraction of the third fluorescent particle 301 can be 10%-30%, for example, 10%-20%, 20%-30%, 15%-25%, etc. Within this volume fraction range, the distribution density of the third fluorescent particle 401 in the fluoride ceramic matrix 100 is relatively moderate, allowing it to cooperate with the first fluorescent particle 201 and the second fluorescent particle 301, resulting in higher red light conversion efficiency.

[0040] In this application, the emission peak refers to the highest peak value in the fluorescence spectrum emitted by the fluorescent particle after excitation. This highest peak value often corresponds to the main color emitted by the fluorescent particle. Therefore, the main purpose of this application is to obtain fluorescence with three different emission peak positions within the emission wavelength range of 600nm-680nm for red light, wherein the first emission peak, the second emission peak, and the third emission peak are all located within the emission wavelength range and do not overlap with each other, thereby obtaining three different red fluorescences. This broadens the spectrum, provides a solution for realizing a high color purity red light source, and improves the display color gamut.

[0041] Because the first fluorescent particle 201, the second fluorescent particle 301, and the third fluorescent particle 401 have different particle sizes and morphologies, they facilitate good filling during subsequent sintering, resulting in a denser structure. In a more preferred embodiment, the particle shapes of the first, second, and third fluorescent particles are configured as at least two of the following: rod-shaped, spherical, and polyhedral. In this embodiment, because the configurations of the first, second, and third fluorescent particles are not completely identical, their emission wavelengths do not completely overlap, and the entire emission wavelength range of the red fluorescent ceramic can completely cover the 600nm-680nm range.

[0042] The red fluorescent ceramic 10 provided in this application features a first, second, and third fluorescent particle whose spectra complement each other during red light conversion, enabling high-purity red light emission with a spectrum covering the range from orange-red to deep red. It also exhibits high fluorescence conversion efficiency and high thermal conductivity, potentially yielding a broad-spectrum red fluorescent material. This provides a solution for achieving high-purity red light sources, improving the display color gamut, and potentially further reducing the cost of laser display light sources.

[0043] The aforementioned red fluorescent ceramic 10 can be prepared by the following method:

[0044] First, a fluoride ceramic matrix is ​​prepared using chlorides and ammonium fluoride as raw materials. The appropriate chloride is selected as the raw material based on the composition of the fluoride ceramic matrix. Taking the preparation of calcium fluoride as an example:

[0045] Calcium chloride and ammonium fluoride were used as raw materials, weighed according to an elemental ratio of calcium ions to fluoride ions of 1:2. First, the calcium chloride raw material was dissolved in deionized water, continuously stirred to ensure uniform dispersion, resulting in solution a. Then, the ammonium fluoride raw material was dissolved in deionized water, resulting in solution b. Solution b was added dropwise to solution a, with rapid stirring during addition, until the reaction was complete, resulting in reaction solution c. Reaction solution c was allowed to stand at room temperature for 0.5-2 hours. The aged reaction solution c was centrifuged, and the middle portion of the precipitate was collected to obtain calcium fluoride gel. The obtained calcium fluoride gel was washed 2-3 times with deionized water, dried, and then the resulting calcium fluoride powder was calcined under vacuum to obtain high-purity calcium fluoride powder. The prepared calcium fluoride powder was mixed for later use.

[0046] Fluoride powder is weighed and mixed with first fluorescent particles, second fluorescent particles and third fluorescent particles in a predetermined ratio, and then dispersed in an organic solvent, such as ethanol. Agate balls are added as the ball milling medium for ball milling. After ball milling, a low-temperature sintering aid and a dispersant are added and mixed to obtain ceramic powder. By introducing the low-temperature sintering aid, the sintering temperature can be reduced in the subsequent sintering process, thereby avoiding the introduction of carbon pollution.

[0047] The stirring rate during mixing can be 100 r / min. After mixing, the powder is dried, further ground to reduce the particle size, and then sieved to obtain composite ceramic powder.

[0048] Composite ceramics are obtained by sintering ceramic powder. Sintering can be carried out in a vacuum environment. Sintering can be carried out by hot pressing or SPS sintering. The sintering temperature can be 600-900℃, preferably 650-800℃, the pressure is 40-100Mpa, the holding time is 2-10h, and the vacuum degree is less than 10-2Pa.

[0049] After sintering, the ceramic is annealed at a temperature of 300–500°C for 1–10 hours. Then it is ground, polished, and cut to form red fluorescent ceramic.

[0050] The present application will be further described below with reference to specific embodiments:

[0051] Example 1

[0052] This embodiment provides a red fluorescent ceramic, a fluoride ceramic matrix, and first fluorescent particles, second fluorescent particles, and third fluorescent particles distributed within the fluoride ceramic matrix. The fluoride ceramic matrix comprises calcium fluoride and magnesium fluoride. The volume content of calcium fluoride is 45%, and the volume content of magnesium fluoride is 5%.

[0053] The first fluorescent particle is CaAlSiN3:Eu 2+ The phosphor, with a volume content of 32%, has an average particle size of approximately 15 μm and a long rod-shaped appearance. The second fluorescent particle is selected from (Ca,Sr)AlSiN3:Eu 2+ The phosphor has a volume content of 8%, an average particle size of approximately 20 μm, and a near-spherical shape. The third fluorescent particle is K₂SiF₆:Mn. 4+ The phosphor has a volume content of 10%, an average particle size of about 27 μm, and a polyhedral shape.

[0054] Example 2

[0055] This embodiment provides a red fluorescent ceramic, a fluoride ceramic matrix, and first fluorescent particles, second fluorescent particles, and third fluorescent particles distributed within the fluoride ceramic matrix. The fluoride ceramic matrix comprises calcium fluoride and strontium fluoride. The volume content of calcium fluoride is 32%, and the volume content of strontium fluoride is 8%.

[0056] The first fluorescent particle is CaAlSiN3:Eu 2+ The phosphor, with a volume content of 40%, has an average particle size of approximately 15 μm and a long rod-shaped appearance. The second fluorescent particle is selected from (Ca,Sr)AlSiN3:Eu 2+ The phosphor, with a volume content of approximately 10%, has an average particle size of about 20 μm and a near-spherical shape. The third fluorescent particle is K₂SiF₆:Mn. 4+ The phosphor has a volume content of 10%, an average particle size of about 27 μm, and a polyhedral shape.

[0057] Example 3

[0058] This embodiment provides a red fluorescent ceramic, a fluoride ceramic matrix, and first fluorescent particles, second fluorescent particles, and third fluorescent particles distributed within the fluoride ceramic matrix. The fluoride ceramic matrix comprises calcium fluoride and barium fluoride. The volume content of calcium fluoride is 35%, and the volume content of barium fluoride is 5%.

[0059] The first fluorescent particle is CaAlSiN3:Eu 2+The phosphor, with a volume content of 37%, has an average particle size of approximately 15 μm and a long rod-shaped appearance. The second fluorescent particle is selected from (Ca,Ba)AlSiN3:Eu 2+ The phosphor has a volume content of 8%, an average particle size of approximately 20 μm, and a near-spherical shape. The third fluorescent particle is K₂SiF₆:Mn. 4+ The phosphor has a volume content of 15%, an average particle size of about 27 μm, and a polyhedral shape.

[0060] Example 4

[0061] This embodiment provides a red fluorescent ceramic, a fluoride ceramic matrix, and first fluorescent particles, second fluorescent particles, and third fluorescent particles distributed within the fluoride ceramic matrix. The fluoride ceramic matrix comprises calcium fluoride and magnesium fluoride. The volume content of calcium fluoride is 35%, and the volume content of strontium fluoride is 15%.

[0062] The first fluorescent particle is CaAlSiN3:Eu 2+ The phosphor, with a volume content of 35%, has an average particle size of approximately 15 μm and a long rod-shaped appearance. The second fluorescent particle is selected from (Ca,Sr,Ba)AlSiN3:Eu 2+ The phosphor, with a volume content of approximately 10%, has an average particle size of about 20 μm and a near-spherical shape. The third fluorescent particle is K₂SiF₆:Mn. 4+ The phosphor has a volume content of 15%, an average particle size of about 27 μm, and a polyhedral shape.

[0063] See Figure 2 This embodiment also provides a light source device 1, including a light source 30 and a wavelength conversion device 20. In this embodiment, the wavelength conversion device 20 includes the red fluorescent ceramic 10 of any of the above embodiments. It is understood that the wavelength conversion device 20 may also include fluorescent ceramics of other colors, and this embodiment does not limit this.

[0064] The light source 30 is used to emit excitation light, such as blue light. The wavelength conversion device 20 is used to receive the excitation light and convert it into laser light for emission. The wavelength of the emitted laser light is different from the wavelength of the incident excitation light. More specifically, when the excitation light is incident on a red fluorescent material, it is converted into red light.

[0065] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A red fluorescent ceramic, characterized in that, include: The fluoride ceramic matrix and the first fluorescent particles, the second fluorescent particles and the third fluorescent particles distributed in the fluoride ceramic matrix, wherein the first fluorescent particles have a first emission peak, the second fluorescent particles have a second emission peak, and the third fluorescent particles have a third emission peak. The red fluorescent ceramic has an emission wavelength range of 600nm-680nm; wherein the first emission peak, the second emission peak and the third emission peak are all located within the emission wavelength range and do not overlap with each other.

2. The red fluorescent ceramic according to claim 1, characterized in that, The first fluorescent particle has a first emission wavelength, the second fluorescent particle has a second emission wavelength, and the third fluorescent particle has a third emission wavelength; wherein any two of the first emission wavelength, the second emission wavelength, and the third emission wavelength at least partially overlap.

3. The red fluorescent ceramic according to claim 2, characterized in that, The first emission wavelength is 600nm-650nm; the second emission wavelength is 630nm-680nm; and the third emission wavelength is 600nm-650nm.

4. The red fluorescent ceramic according to claim 1, characterized in that, The first emission peak is located at 610nm-620nm; the second emission peak is located at 650nm-670nm; and the third emission peak is located at 630nm-640nm.

5. The red fluorescent ceramic according to claim 4, characterized in that, The first emission peak is located at 620 nm; the second emission peak is located at 650 nm; and the third emission peak is located at 630 nm.

6. The red fluorescent ceramic according to any one of claims 1-5, characterized in that, The first fluorescent particle is CaAlSiN3:Eu 2+ The phosphor and the second fluorescent particle are selected from (Ca,Sr)AlSiN3:Eu 2+ Phosphor, (Ca,Ba)AlSiN3:Eu 2+ Phosphor, (Ca,Sr,Ba)AlSiN3:Eu 2+ At least one of the phosphors, wherein the third fluorescent particle is K2SiF6:Mn 4+ Fluorescent powder.

7. The red fluorescent ceramic according to any one of claims 1-5, characterized in that, The fluoride ceramic matrix includes calcium fluoride, and the fluoride ceramic matrix also includes at least one of magnesium fluoride, strontium fluoride, and barium fluoride.

8. The red fluorescent ceramic according to any one of claims 1-5, characterized in that, The volume content of the first fluorescent particle is 32%-40%; the volume content of the second fluorescent particle is 8%-10%; the volume content of the third fluorescent particle is 10%-30%; and the volume content of the fluoride ceramic matrix is ​​20%-50%.

9. The red fluorescent ceramic according to any one of claims 1-5, characterized in that, The diameter of the first fluorescent particle is 8-16 μm; the diameter of the second fluorescent particle is 18-22 μm; and the diameter of the third fluorescent particle is 23-30 μm.

10. The red fluorescent ceramic according to claim 9, characterized in that, The first fluorescent particle, the second fluorescent particle, and the third fluorescent particle are configured to have a particle shape of at least two of the following: rod-shaped, spherical, and polyhedral.

11. A light source device, characterized in that, It includes a light source and a wavelength conversion device, wherein the wavelength conversion device includes red fluorescent ceramic as described in any one of claims 1-10.

12. The method for preparing red fluorescent ceramics according to any one of claims 1-10, characterized in that, The process includes: mixing fluoride powder with first fluorescent particles, second fluorescent particles and third fluorescent particles, dispersing the mixture in an organic solvent, ball milling the mixture, adding a sintering aid to obtain ceramic powder, sintering the ceramic powder to obtain composite ceramic, and then annealing the composite ceramic to form the red fluorescent ceramic.

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