Fluorescent ceramic, preparation method thereof and light source device

Abstract

The fluorescent ceramic comprises a matrix ceramic phase, a fluorescent phase, a light scattering phase and air holes, the matrix ceramic phase comprises a plurality of matrix particles, the fluorescent phase comprises a plurality of fluorescent particles, the fluorescent particles are dispersed in the matrix ceramic phase, the light scattering phase comprises a plurality of light scattering particles, the light scattering particles are dispersed in the matrix ceramic phase, and the air holes are formed in the matrix ceramic phase. At least part of the pores are dispersed at the junction of at least one of the matrix particles, the fluorescent particles and the light scattering particles. When the exciting light is propagated in the fluorescent ceramic, the exciting light can be scattered at the interface between the exciting light and the fluorescent ceramic under the conditions that the exciting light enters the fluorescent particles from the light scattering particles or enters the light scattering particles or the fluorescent particles from the air holes and the like. The scattering phenomenon enables the exciting light to be uniformly emitted into the fluorescent particles, the contact area of the exciting light and the fluorescent particles is increased, and then the efficient absorption and conversion of the exciting light are improved. The embodiment of the invention also provides a preparation method of the fluorescent ceramic and a light source device.

Description

Technical Field

[0001] The present application relates to the technical field of light source equipment, and in particular to a fluorescent ceramic and a preparation method thereof, and a light source device. Background Art

[0002] As the application of high-power laser diodes for white light illumination continues to expand, the demand for high-temperature-resistant, thermally stable fluorescent conversion materials is becoming increasingly urgent. As the power density of light sources continues to increase, issues such as heat dissipation and conversion efficiency in fluorescent ceramics have become increasingly prominent. Existing fluorescent ceramics lack thermal conductivity and high transmittance, but lack light scattering, making them difficult to meet the needs of laser illumination, and even more so, high-power lighting. Summary of the Invention

[0003] The embodiments of the present application provide a fluorescent ceramic, a preparation method thereof, and a light source device to at least partially improve the above-mentioned technical problems.

[0004] In a first aspect, an embodiment of the present application provides a fluorescent ceramic, comprising a matrix ceramic phase, a fluorescent phase, a light scattering phase, and pores, wherein the matrix ceramic phase comprises a plurality of matrix particles, the fluorescent phase comprises a plurality of fluorescent particles, the fluorescent particles are dispersed in the matrix ceramic phase, the light scattering phase comprises a plurality of light scattering particles, the light scattering particles are dispersed in the matrix ceramic phase, and at least part of the pores are dispersed at the junction of at least one of the matrix particles, the fluorescent particles, and the light scattering particles, wherein the light scattering phase comprises at least one of the general structural formula A 2-x B2O 7-3x / 2 A compound wherein 0.1≤x≤1, A is selected from at least one of bismuth, indium, tin, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, and B is selected from at least one of manganese, vanadium, lead, titanium, zirconium and hafnium.

[0005] In one embodiment, in the fluorescent ceramic, the refractive index of the light scattering phase at 632.8 nm is 1.9-2.4.

[0006] In one embodiment, in the fluorescent ceramic, the refractive index of the fluorescent particles is greater than the refractive index of the pores and less than the refractive index of the light scattering particles.

[0007] In one embodiment, at least a portion of the light scattering particles are in contact with the fluorescent particles, and at least a portion of the pores are in contact with at least one of the light scattering particles and the fluorescent particles.

[0008] In one embodiment, in the fluorescent ceramic, the particle size of the light scattering particles is 0.4 μm-25 μm, and / or the volume proportion of the light scattering particles is 5%-20%.

[0009] In one embodiment, in the fluorescent ceramic, the particle size of the fluorescent particles is 0.2 μm-30 μm, and / or the volume proportion of the fluorescent particles is 20%-50%.

[0010] In one embodiment, the particle size of the matrix particles is 0.5 μm-20 μm, and / or the volume proportion of the matrix particles is 30%-45%.

[0011] In one embodiment, in the fluorescent ceramic, the pores have a diameter of 0.1 μm to 2 μm, and / or the volume of the pores accounts for 1% to 15%.

[0012] In a second aspect, an embodiment of the present application provides a method for preparing a fluorescent ceramic, comprising:

[0013] Prepare light scattering particle powder, the light scattering particles include at least one structural formula A 2-x B2O 7-3x / 2 A compound of bismuth, indium, tin, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, and B is selected from at least one of manganese, vanadium, lead, titanium, zirconium and hafnium;

[0014] Fluorescent particle powder and matrix particle powder are prepared, and the matrix particle powder, light scattering particle powder and fluorescent particle powder are mixed and calcined to form composite fluorescent ceramic powder. After the composite fluorescent ceramic powder is formed, it is sintered to form fluorescent ceramic.

[0015] In a third aspect, an embodiment of the present application provides a light source device, comprising a light source and a fluorescent ceramic as described in the first aspect above, wherein the light source emits excitation light, the fluorescent ceramic is located in the optical path of the excitation light, and the fluorescent ceramic is used to convert the excitation light into stimulated light.

[0016] The fluorescent ceramics and their preparation methods and light source devices provided in the embodiments of the present application utilize the difference in refractive index between the light scattering phase and the pores and the fluorescent particles. When the excitation light propagates in the fluorescent ceramic, when it enters the fluorescent particles from the light scattering particles or is incident on the light scattering particles or fluorescent particles from the pores, the excitation light will be scattered at the interface between the two. The scattering phenomenon can make the excitation light uniformly emitted into the fluorescent particles, increase the contact area between the excitation light and the fluorescent particles, and thus improve the efficient absorption and conversion of the excitation light, thereby improving the light conversion efficiency and light extraction efficiency of the fluorescent ceramic. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A schematic structural diagram of a light source device proposed in an embodiment of the present application;

[0019] Figure 2 A schematic diagram of the structure of a fluorescent ceramic proposed in an embodiment of the present application;

[0020] Figure 3 This is a schematic flow chart of a method for preparing fluorescent ceramics proposed in an embodiment of the present application.

[0021] Reference numerals: light source device 1 , fluorescent ceramic 10 , matrix particles 11 , fluorescent particles 12 , light scattering particles 13 , pores 14 , light source 20 . DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. 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 those skilled in the art without creative work are within the scope of protection of this application.

[0023] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," and "fixed" should be interpreted broadly. For example, these terms may refer to fixed, removable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; internal communication between two components; surface contact only; or surface contact through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0024] In addition, the terms "first", "second", etc. are only used to distinguish descriptions and should not be understood as specific or special structures. The descriptions of the terms "some embodiments", "other embodiments", etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this application, the schematic representations 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. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this application and the features of the different embodiments or examples, unless they are contradictory.

[0025] The present application embodiment provides a light source device 1, see Figure 1 The light source device 1 can be applied to a projection system, a lighting system, etc. The specific setting method and application scenario of the light source device 1 are not limited here.

[0026] The light source device 1 may include a fluorescent ceramic 10 and a light source 20. The light source 20 may be a laser light source 20 or a fluorescent light source 20. The light source 20 emits excitation light (such as Figure 1 The excitation light can be ultraviolet light, visible light or near infrared light of different wavelengths, and this embodiment is not limited thereto. The fluorescent ceramic 10 is located in the optical path of the excitation light, and the fluorescent ceramic 10 can be used to convert the excitation light into stimulated light (such as Figure 1 When the excitation light emitted by the light source 20 strikes the fluorescent ceramic 10, the fluorescent ceramic 10 absorbs the excitation light and converts it into stimulated light. For example, the fluorescent ceramic 10 can be used to convert blue light. When blue light strikes the fluorescent ceramic 10, the fluorescent ceramic 10 absorbs the blue light energy and converts it into yellow, red, or green light energy, thereby achieving light output of a specific color.

[0027] Furthermore, the shape and size of the fluorescent ceramic 10 can be designed according to specific practical needs and are not limited here. For example, the fluorescent ceramic 10 can be made into different shapes such as round, square, or strip, and the thickness of the fluorescent ceramic 10 can be adjusted to suit a specific scene or light source 20.

[0028] See also Figure 2The fluorescent ceramic 10 includes a matrix ceramic phase, a fluorescent phase, a light-scattering phase, and pores 14. The matrix ceramic phase includes a plurality of matrix particles 11. The fluorescent phase includes a plurality of fluorescent particles 12. The fluorescent particles 12 are dispersed within the matrix ceramic phase, that is, the fluorescent particles 12 can be dispersed among the plurality of matrix particles 11. The light-scattering phase can include a plurality of light-scattering particles 13. The plurality of light-scattering particles 13 are dispersed within the matrix ceramic phase, that is, the light-scattering particles 13 can also be distributed among the plurality of matrix particles 11. At least a portion of the pores 14 are dispersed at the interface between at least one of the matrix particles 11, the fluorescent particles 12, and the light-scattering particles 13. The light-scattering phase and the pores 14 can improve the absorption and conversion rate of the excitation light, thereby improving the luminous efficiency of the fluorescent ceramic 10.

[0029] In a more specific embodiment, at least a portion of the light-scattering particles 13 is in contact with the fluorescent particles 12, and at least a portion of the pores 14 is in contact with at least one of the light-scattering particles 13 and the fluorescent particles 12. The excitation light can propagate through the light-scattering particles 13 to the fluorescent particles 12, and / or through the pores 14 to the fluorescent particles 12, and / or through the pores 14 to the light-scattering particles 13 and then to the fluorescent particles 12. Furthermore, the refractive index of the fluorescent particles 12 is greater than the refractive index of the pores 14, and the refractive index of the fluorescent particles 12 is less than the refractive index of the light-scattering particles 13. The refractive indices of the fluorescent particles 12, the pores 14, and the light-scattering particles 13 are different. When the light-scattering particles 13 enter the fluorescent particles 12 or the pores 14 are incident on the light-scattering particles 13 or the fluorescent particles 12, the excitation light will be refracted at the interface between the two. The refraction phenomenon can change the propagation direction of the excitation light, increase the travel distance of the excitation light in the fluorescent ceramic 10 , effectively improve the absorption rate and conversion rate of the fluorescent ceramic 10 to the excitation light, and improve the energy utilization rate of the fluorescent ceramic 10 .

[0030] In one embodiment, the fluorescent particles 12 may be Y3Al5O 12 :Ce 3+ Fluorescent particles or Lu3Al5O 12 :Ce 3+ Phosphor particles or Gd3(Al,Ga)5O 12 :Ce 3+ Fluorescent particles, using Y3Al5O 12 :Ce 3+ The fluorescent ceramic 10 with fluorescent particles exhibits good chemical stability and high emission efficiency, using Lu3Al5O 12 :Ce 3+ The fluorescent ceramic 10 of fluorescent particles has higher quantum efficiency and thermal stability. 12 :Ce 3+The emission spectrum of the fluorescent ceramic 10 of the fluorescent particles is relatively wide. The design and selection of the fluorescent particles 12 can be carried out according to specific implementation requirements and implementation scenarios, and this embodiment does not limit this.

[0031] If the volume percentage of the fluorescent particles 12 in the fluorescent ceramic 10 is too large, the transparency of the fluorescent ceramic 10 may be reduced, and the mechanical strength and thermal stability of the fluorescent ceramic 10 may also be reduced. If the volume percentage of the fluorescent particles 12 in the fluorescent ceramic 10 is too small, the fluorescent effect of the fluorescent ceramic 10 may be affected. In one embodiment of the present application, the volume percentage of the fluorescent particles 12 in the fluorescent ceramic 10 is 20%-50%. This ensures that the fluorescent ceramic 10 has good mechanical strength and thermal stability.

[0032] In another embodiment, the particle size of the fluorescent particles 12 is 0.2 μm-30 μm, which can effectively prevent the particle size of the fluorescent particles 12 from affecting the structural performance and sintering performance of the fluorescent ceramic 10, and can not only ensure the absorption rate of the excitation light of the fluorescent ceramic 10, but also improve the sintering performance of the fluorescent ceramic 10.

[0033] To enable the fluorescent ceramic 10 to adapt to a light source 20 with greater illumination power and achieve better illumination effects, the matrix ceramic phase in this embodiment can be made of a highly thermally conductive material. This highly thermally conductive matrix ceramic phase can improve the thermal conductivity of the fluorescent ceramic 10, enabling the fluorescent ceramic 10 to conduct heat quickly and withstand the higher-power light source 20. Exemplarily, the matrix ceramic phase can be selected from at least one of aluminum oxide, magnesium oxide, beryllium oxide, boron nitride, aluminum nitride, MgO-Al2O3, and a diamond / aluminum composite material.

[0034] In one embodiment, the particle size of the matrix particles 11 is 0.5 μm to 20 μm. This prevents the matrix ceramic phase from having an excessively large particle size, which would reduce the material's density and thus affect the mechanical strength and durability of the fluorescent ceramic 10. It also prevents the matrix ceramic phase from having an excessively small particle size, which would reduce the thermal conductivity and sintering properties of the fluorescent ceramic 10.

[0035] In another embodiment, in the fluorescent ceramic 10 , the volume proportion of the matrix particles 11 is 30%-45%. The mechanical strength and thermal stability of the fluorescent ceramic 10 can be ensured by controlling the volume proportion of the matrix particles 11 , thereby improving the mechanical strength of the fluorescent ceramic 10 .

[0036] The light scattering phase may include at least one structural formula A 2-x B2O 7-3x / 2 Compounds, for example, the light scattering phase may include Gd 1.2 Zr2O 5.8 、La 1.2 Zr2O 5.8 、Y 1.8Hf2O 6.7 and at least one of Lu2Ti2O7, etc. For example, the light scattering phase can be Gd 1.2 Zr2O 5.8 and La 1.2 Zr2O 5.8 A mixture of the two. The composition of the light scattering phase can be adjusted to achieve 2-x B2O 7-3x / 2 The refractive index of the light scattering phase is adjusted to achieve control of the light scattering performance of the light scattering phase. Compared with a single oxide, the light scattering phase in this embodiment can have a higher refractive index and phase stability at high temperatures, thereby ensuring the refractive effect of the excitation light in the fluorescent ceramic 10, so as to improve the absorption conversion rate of the fluorescent ceramic 10 for the excitation light. Wherein, 0.1≤x≤1, such as 0.1, 0.2, 0.3, 0.5, 0.6, 0.7, 0.8, 0.9, 1; A is selected from at least one of bismuth, indium, tin, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium; B is selected from at least one of manganese, vanadium, lead, titanium, zirconium and hafnium.

[0037] It is understandable that the light scattering phase may also include other compounds to improve its own structural properties and sintering properties and the refractive index of the fluorescent ceramic 10 .

[0038] In one embodiment, the light-scattering phase in the fluorescent ceramic 10 has a refractive index of 1.9-2.4 at 632.8 nm. The light-scattering phase has a high refractive index. Light scattering by the light-scattering phase allows the excitation light to be scattered throughout the fluorescent ceramic 10, allowing it to be fully converted, thereby improving the conversion efficiency of the fluorescent ceramic 10.

[0039] In one embodiment, in the fluorescent ceramic 10, the volume proportion of the light scattering phase is 5%-20%, which can avoid the light scattering phase from having too large a volume proportion affecting the thermal conductivity of the fluorescent ceramic 10, and can also avoid the light scattering phase from having too small a volume proportion affecting the absorption conversion rate of the fluorescent ceramic 10.

[0040] In one embodiment, the particle size of the light-scattering particles is 0.4 μm to 25 μm, and the volume fraction of the light-scattering particles in the fluorescent ceramic 10 is 5% to 20%. This ensures the sintering performance and conversion efficiency of the fluorescent ceramic 10 while also improving the scattering effect of the excitation light and ensuring the conversion rate of the fluorescent ceramic 10 to light.

[0041] The fluorescent ceramic 10 in this embodiment has pores 14 therein, and at least part of the pores 14 are dispersed at the junction of at least one of the matrix particles 11, the fluorescent particles 12, and the light scattering particles 13. The porous structure of the fluorescent ceramic 10 improves the absorption rate and conversion rate of the excitation light, further improving the light utilization rate of the fluorescent ceramic 10. In one embodiment, the matrix ceramic phase, the fluorescent phase, and the light scattering phase are not fully densified during the co-sintering process, and a plurality of pores 14 are formed in and between the matrix ceramic phase, the fluorescent phase, and the light scattering phase. In another embodiment, a pore-forming agent is added to the fluorescent ceramic 10. During the sintering process of the fluorescent ceramic 10, the pore-forming agent is decomposed by heat to form gas, which eventually leads to the formation of pores 14 inside the fluorescent ceramic 10.

[0042] In one embodiment, the pores 14 may have a diameter of 0.1 μm to 2 μm. This is to avoid the pores 14 being too large, which may affect the structural and heat dissipation properties of the fluorescent ceramic 10, and to avoid the pores 14 being too small, which may affect the light scattering effect of the fluorescent ceramic 10 and the absorption conversion rate of the excitation light.

[0043] In another embodiment, the volume of the pores 14 in the fluorescent ceramic 10 is 1%-15%, which can prevent the pores 14 from affecting the structural strength of the fluorescent ceramic 10 when the volume is too large, and can also prevent the pores 14 from affecting the scattering effect of the excitation light in the fluorescent ceramic 10 when the volume is too small.

[0044] The fluorescent ceramic 10 can be prepared as follows: Figure 3 Shown, including:

[0045] Step S210: preparing light scattering particle powder, the light scattering particles including at least one structural formula A 2- x B2O 7-3x / 2 of compounds.

[0046] Provide light scattering particle powder, according to the general formula A of light scattering particles 2-x B2O 7-3x / 2 , the molar fractions of each component are proportioned. Wherein, 0.1≤x≤1, A is selected from at least one of bismuth, indium, tin, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium or lutetium, and B is selected from at least one of manganese, vanadium, lead, titanium, zirconium or hafnium. Exemplarily, the compound in the light scattering particles can be La 1.2 Zr2O 5.8, the molar fractions of La2O3 and ZrO2 can be proportioned. And each component is dissolved to form a solution. Stir evenly to prepare a metal salt solution with a metal ion concentration of 0.5mol / L-8mol / L, and control the pH value of the solution to 7-10. Add fuel to the solution, wherein the fuel can be at least one of ethanol, glycine, urea, citric acid, ethylene glycol, etc., and continue to stir evenly. Then heat the solution to 70℃-100℃ in a water bath until it evaporates into a viscous state. Then transfer it to a microwave heating device for further heat treatment. The microwave heating temperature can be 100℃-110℃, and the heating time is 5min-10min. The resulting product is post-treated to obtain light scattering particle powder. The post-treatment here may include grinding, sieving, and calcination at 500℃-800℃.

[0047] Step S220: preparing fluorescent particle powder and matrix particle powder, mixing the matrix particle powder, light scattering particle powder and fluorescent particle powder, and calcining them to form composite fluorescent ceramic powder.

[0048] Prepare fluorescent particle powder and matrix particle powder. Fluorescent particle powder can be selected from Y3Al5O 12 :Ce 3+ Phosphor particles or Lu3Al5O 12 :Ce 3+ Phosphor particles or Gd3(Al,Ga)5O 12 :Ce 3+ One of the fluorescent particle powders.

[0049] The light scattering particle powder and the matrix particle powder are weighed in the required proportion, and the light scattering particle powder and the matrix particle powder are placed in a mixer and stirred thoroughly to form a fluorescent ceramic slurry. The residual organic components in the fluorescent ceramic slurry are then removed by low-temperature calcination, that is, the fluorescent ceramic slurry is subjected to low-temperature calcination. The low-temperature calcination time can be 0.5h-3h, and the low-temperature calcination temperature is 600℃-900℃. Removing the residual organic components in the fluorescent ceramic slurry can avoid the organic components from interfering with subsequent sintering. The mixed powder can be sieved with 100-120 mesh, preferably 120 mesh, to ensure that there are no larger particles or impurities in the powder. After sieving, the powder is collected for later use.

[0050] Add fluorescent particle powder, and mix the fluorescent particle powder, light scattering particle powder and matrix particle powder evenly to form a mixed powder. And according to the measurement of light scattering particle powder and matrix particle powder, prepare appropriate amounts of sintering aid, adhesive and pore-forming agent. For example, the sintering aid can be selected from one of magnesium fluoride, calcium fluoride, magnesium oxide, calcium carbonate, lithium fluoride, lanthanum trioxide, silicon dioxide and tetraethoxysilane, the adhesive can be polyvinyl butyral (PVB) and the like, and the pore-forming agent can be selected from one of polymethyl methacrylate (PMMA) or starch or carbon black, etc. The specific sintering aid, adhesive and pore-forming agent should be selected according to the specific components of the fluorescent ceramic and the proportion of each component, and this embodiment does not limit it. During the mixing process, the sintering aid, adhesive and pore-forming agent are added. For example, the mass fraction of the sintering aid in the mixed powder is 0.5%-3%, the mass fraction of the binder is 0.5%-3%, and the mass fraction of the pore-forming agent is 2%-15%. The mixed powder is then dried and sieved, for example, through a 100-120 mesh sieve to ensure that there are no large particles or impurities in the powder. After sieving, the powder is collected for later use.

[0051] The sieved powder is placed in a calcining furnace for calcination at a temperature of 700°C to 900°C for 2 to 3 hours. The powder is sieved again to obtain a composite fluorescent ceramic powder.

[0052] Step S230: After forming the composite fluorescent ceramic powder, sintering it to form fluorescent ceramics.

[0053] After the composite fluorescent ceramic powder is formed, the composite fluorescent ceramic powder can be formed by dry pressing or static pressing, and a pressure value of 10MPa-100MPa is used to obtain a semi-finished product of the fluorescent ceramic. The specific pressure value is determined according to factors such as the particle size of the fluorescent ceramic powder and the forming method, and this embodiment does not limit it.

[0054] The pre-sintered fluorescent ceramic semi-finished product is placed in a vacuum or protective atmosphere for hot pressing or spark plasma sintering. Sintering the fluorescent ceramic under a certain pressure can control the grain size within the fluorescent ceramic, refine the grains, and improve the mechanical strength of the fluorescent ceramic. The fluorescent ceramic semi-finished product is placed in a vacuum furnace or a protective atmosphere furnace. More specifically, sintering can be performed in a variety of atmospheres, such as vacuum, nitrogen, and argon, under pressureless, hot pressing, or spark plasma conditions.

[0055] During the sintering process, the temperature in the furnace gradually increases, reaching a maximum sintering temperature of 1400°C to 1700°C. The pore-forming agent in the semi-finished fluorescent ceramic product generates gas upon heating, which forms pores within the fluorescent ceramic. For example, the pore-forming agent can be PMMA, which decomposes during sintering, generating gas that ultimately leads to pores within the fluorescent ceramic. Furthermore, the sintering hold time can be 2 to 10 hours.

[0056] The fluorescent ceramic is annealed in air at a temperature of 900°C-1250°C for 2-80 hours to eliminate the internal stress generated during the sintering process and improve the stability of the fluorescent ceramic. The fluorescent ceramic in this embodiment can also be ground, polished, cut and other processes.

[0057] The solution of this application is described in more detail below with reference to specific embodiments.

[0058] Example 1

[0059] This embodiment provides a fluorescent ceramic, the general formula of the light scattering phase is Gd 1.2 Zr2O 5.8 The matrix ceramic phase can be alumina, and the fluorescent particle powder can be Y3Al5O 12 :Ce 3+ Fluorescent particles.

[0060] The fluorescent ceramics are prepared as follows:

[0061] According to the general formula of the light scattering phase Gd 1.2 Zr2O 5.8 , proportion the molar fractions of Gd2O3 and ZrO2, and dissolve the components to form a solution. Stir evenly to prepare a metal salt solution with a metal ion concentration of 0.5 mol / L, and control the pH value of the solution to 7. Add ethanol or other fuel to the solution and continue to stir evenly. Then heat the solution to 70°C in a water bath until it evaporates into a viscous state. Then transfer it to a microwave heating device for further heat treatment. The microwave heating temperature can be 100°C and the heating time is 5 minutes. The resulting product is post-treated to obtain light scattering particle powder.

[0062] Gd 1.2 Zr2O 5.8 The powder of Gd and alumina powder were weighed in a volume ratio of 1:9. 1.2 Zr2O 5.8The powder and alumina powder are placed in a mixer and stirred thoroughly to form a slurry. The fluorescent ceramic slurry is then calcined at a low temperature for 0.5 hours at a temperature of 600°C. The mixed powder can be sieved through a 100-mesh sieve and collected for later use.

[0063] Add appropriate amount of commercially available Y3Al5O 12 :Ce 3+ Fluorescent particle powder, the volume ratio of fluorescent particle powder to alumina powder is 1:1, and Y3Al5O 12 :Ce 3+ Fluorescent particle powder, Gd 1.2 Zr2O 5.8 The powder and alumina powder are evenly mixed to form a mixed powder. According to the measurement of light scattering particle powder and matrix particle powder, prepare appropriate amounts of polyvinyl butyral, magnesium fluoride, and polymethyl methacrylate. During the mixing process, gradually add a small amount of polyvinyl butyral, magnesium fluoride, and polymethyl methacrylate to promote the uniform distribution of the powder and the subsequent sintering process. For example, the mass fraction of polyvinyl butyral in the mixed powder is 0.5%, the mass fraction of magnesium fluoride in the mixed powder is 0.5%, and the mass fraction of polymethyl methacrylate in the mixed powder is 2%. The mixed powder is then dried and sieved to ensure that there are no large particles or impurities in the powder. After sieving, the powder is collected for later use.

[0064] The sieved powder is placed in a high-temperature furnace for calcination at 700°C for 2 hours. The powder is sieved again to obtain a composite fluorescent ceramic powder.

[0065] The calcined powder is sieved twice to obtain fluorescent ceramic powder.

[0066] The fluorescent ceramic powder is dry-pressed at a pressure of 10 MPa to produce a semi-finished fluorescent ceramic product. The semi-finished fluorescent ceramic product is then placed in a vacuum and hot-pressed to form the finished fluorescent ceramic product. During the sintering process, the temperature in the furnace gradually increases, reaching a maximum temperature of 1400°C, and the sintering temperature is maintained for 10 hours.

[0067] The fluorescent ceramic block is annealed in air at 900°C for 2 hours to eliminate the internal stress generated during the sintering process and improve the stability of the fluorescent ceramic. The fluorescent ceramic in this embodiment can also be ground, polished, cut, and other processes.

[0068] Example 2

[0069] This embodiment provides a fluorescent ceramic, the general formula of the light scattering phase is La 1.2 Zr2O5.8 The matrix ceramic phase can be magnesium oxide, and the fluorescent particle powder can be Lu3Al5O 12 :Ce 3+ Fluorescent particles.

[0070] The fluorescent ceramics are prepared as follows:

[0071] According to the general formula of the light scattering phase La 1.2 Zr2O 5.8 , proportion the molar fractions of La2O3 and ZrO2, and dissolve the components to form a solution. Stir evenly to prepare a metal salt solution with a metal ion concentration of 8 mol / L, and control the pH value of the solution to 10. Add ethanol or other fuel to the solution and continue to stir evenly. Then heat the solution to 100°C in a water bath until it evaporates into a viscous state. Then transfer it to a microwave heating device for further heat treatment. The microwave heating temperature can be 110°C and the heating time is 10 minutes. The resulting product is post-treated to obtain light scattering particle powder.

[0072] La 1.2 Zr2O 5.8 The powder of La and the powder of magnesium oxide are weighed in a volume ratio of 2:3. 1.2 Zr2O 5.8 The powder of the phosphor and magnesium oxide are placed in a mixer and stirred thoroughly to form a slurry. The fluorescent ceramic slurry is then calcined at a low temperature of 900°C for 3 hours. The mixed powder can be sieved through a 120-mesh sieve and then collected for later use.

[0073] Add appropriate amount of commercially available Lu3Al5O 12 :Ce 3+ The volume ratio of fluorescent particle powder to magnesium oxide powder is 7:6. Lu3Al5O 12 :Ce 3+ Fluorescent particle powder, La 1.2 Zr2O 5.8 The powder and alumina powder are evenly mixed to form a mixed powder. According to the measurement of light scattering particle powder and matrix particle powder, prepare appropriate amounts of calcium fluoride, polyvinyl butyral ester, starch, etc. During the mixing process, gradually add a small amount of calcium fluoride, polyvinyl butyral ester, and starch to promote the uniform distribution of the powder and the subsequent sintering process. For example, the mass fraction of calcium fluoride in the mixed powder is 3%, the mass fraction of polyvinyl butyral ester in the mixed powder is 3%, and the mass fraction of starch in the mixed powder is 15%. The mixed powder is then dried and sieved to ensure that there are no large particles or impurities in the powder. After sieving, the powder is collected for later use.

[0074] The sieved powder is placed in a high-temperature furnace for calcination at 900°C for 3 hours. During the calcination process, ensure that the powder is fully heated and does not sinter poorly. The powder is sieved again to obtain the composite fluorescent ceramic powder.

[0075] The calcined powder is screened twice to remove any particulate impurities that may be present and ensure the purity and uniformity of the powder. After the second screening, fluorescent ceramic powder is obtained.

[0076] The fluorescent ceramic powder is statically pressed to form a semi-finished fluorescent ceramic product at a pressure of 100 MPa. The semi-finished fluorescent ceramic product is then placed in a protective atmosphere such as nitrogen for ion sintering, resulting in the finished fluorescent ceramic product. During the sintering process, the temperature in the furnace gradually increases, reaching a maximum temperature of 1700°C, and the sintering temperature is maintained for 2 hours.

[0077] The fluorescent ceramic block is annealed in air at a temperature of 1250° C. for 80 hours to eliminate the internal stress generated during the sintering process and improve the stability of the fluorescent ceramic. The fluorescent ceramic in this embodiment can also be ground, polished, cut, and other processes.

[0078] Example 3

[0079] This embodiment provides a fluorescent ceramic, the light scattering phase of the general formula Y 1.8 Hf2O 6.7 The matrix ceramic phase can be alumina, and the fluorescent particle powder can be Gd3(Al,Ga)5O 12 (GAGG:Ce 3+ ) fluorescent particles.

[0080] The fluorescent ceramics are prepared as follows:

[0081] According to the general formula Y of the light scattering phase 1.8 Hf2O 6.7 , proportion the molar fractions of Y2O3 and HfO2, and dissolve the components to form a solution. Stir evenly to prepare a metal salt solution with a metal ion concentration of 6 mol / L, and control the pH value of the solution to 8. Add urea or other fuel to the solution and continue stirring evenly. Then heat the solution to 80°C in a water bath until it evaporates into a viscous state. Then transfer it to a microwave heating device for further heat treatment. The microwave heating temperature can be 105°C and the heating time is 8 minutes. The resulting product is post-treated to obtain light scattering particle powder.

[0082] Y 1.8 Hf2O 6.7 The powder of Y and the powder of aluminum oxide are weighed in a volume ratio of 1:8.1.8 Hf2O 6.7 The powder of the fluorescent ceramic and the powder of the alumina are placed in a mixer and stirred thoroughly to form a slurry. The fluorescent ceramic slurry is then calcined at a low temperature of 800°C for 2 hours. The mixed powder can be sieved through a 110-mesh sieve and then collected for later use.

[0083] Add an appropriate amount of commercially available Gd3(Al,Ga)5O 12 (GAGG:Ce 3+ ) fluorescent particle powder, the volume ratio of fluorescent particle powder to alumina powder is 5:4, Gd3(Al,Ga)5O 12 (GAGG:Ce 3+ ) Fluorescent particle powder, Y 1.8 Hf2O 6.7 The powder of light scattering particles and alumina powder are mixed evenly to form a mixed powder. According to the measurement of light scattering particle powder and matrix particle powder, prepare appropriate amounts of magnesium oxide, polyvinyl butyral ester, carbon black, etc. During the mixing process, gradually add a small amount of magnesium oxide, polyvinyl butyral ester, carbon black, etc. to promote the uniform distribution of the powder and the subsequent sintering process. For example, the mass fraction of magnesium oxide in the mixed powder is 2%, the mass fraction of polyvinyl butyral ester in the mixed powder is 2%, and the mass fraction of carbon black in the mixed powder is 10%. The mixed powder is then dried and sieved to ensure that there are no large particles or impurities in the powder. After sieving, the powder is collected for later use.

[0084] The sieved powder is placed in a high-temperature furnace for calcination at 800°C for 2.5 hours. During the calcination process, ensure that the powder is fully heated and does not sinter poorly. The powder is sieved again to obtain the composite fluorescent ceramic powder.

[0085] The calcined powder is screened twice to remove any particulate impurities that may be present and ensure the purity and uniformity of the powder. After the second screening, fluorescent ceramic powder is obtained.

[0086] The fluorescent ceramic powder is statically pressed to form a semi-finished fluorescent ceramic product at a pressure of 50 MPa. The semi-finished fluorescent ceramic product is then placed in a protective atmosphere such as argon and hot-pressed to form the finished fluorescent ceramic product. During the sintering process, the temperature in the furnace gradually increases, reaching a maximum temperature of 1600°C, and the sintering temperature is maintained for 5 hours.

[0087] The fluorescent ceramic block is annealed in air at a temperature of 1000°C for 50 hours to eliminate the internal stress generated during the sintering process and improve the stability of the fluorescent ceramic. The fluorescent ceramic in this embodiment can also be ground, polished, cut and other processes.

[0088] Example 4

[0089] This embodiment provides a fluorescent ceramic, wherein the general formula of the light scattering phase is Lu2Ti2O7, the matrix ceramic phase can be MgO-Al2O3, and the fluorescent particle powder can be Y3Al5O 12 :Ce 3+ Fluorescent particles.

[0090] The fluorescent ceramics are prepared as follows:

[0091] According to the general formula of the light-scattering phase, Lu₂Ti₂Oₐ, the molar fractions of La₂O₃ and TiO₂ are proportioned and dissolved to form a solution. Stirring is then performed to obtain a metal salt solution with a metal ion concentration of 6 mol / L, and the pH of the solution is controlled at 8. A fuel such as urea is added to the solution and stirring is continued. The solution is then heated in a water bath to 80°C until it evaporates and becomes viscous. The solution is then transferred to a microwave heating device for further heat treatment at a temperature of 105°C for 8 minutes. The resulting product undergoes post-processing to obtain a light-scattering particle powder.

[0092] Weigh Lu₂Ti₂Oₐ powder and MgO-Al₂O₃ powder in a volume ratio of 4:9. Place the powders in a mixer and stir thoroughly to form a slurry. The fluorescent ceramic slurry is then calcined at 800°C for 2 hours. The mixed powders can be sieved through a 110-mesh sieve and collected for later use.

[0093] Add appropriate amount of commercially available Y3Al5O 12 :Ce 3+ The volume ratio of fluorescent particle powder to MgO-Al2O3 powder is 4:9. 12 :Ce 3+Fluorescent particle powder, Lu2Ti2O7 powder, and alumina powder are uniformly mixed to form a mixed powder. Based on the metering of the light-scattering particle powder and the matrix particle powder, appropriate amounts of lanthanum trioxide, polyvinyl butyral, carbon black, etc. are prepared. During the mixing process, small amounts of lanthanum trioxide, polyvinyl butyral, carbon black, etc. are gradually added to promote uniform distribution of the powders and the subsequent sintering process. For example, the mass fraction of lanthanum trioxide in the mixed powder is 2%, the mass fraction of polyvinyl butyral in the mixed powder is 2%, and the mass fraction of carbon black in the mixed powder is 10%. The mixed powder is then dried and sieved to ensure that there are no large particles or impurities in the powder. After sieving, the powder is collected for later use.

[0094] The sieved powder is placed in a high-temperature furnace for calcination at 800°C for 2.5 hours. During the calcination process, ensure that the powder is fully heated and does not sinter poorly. The powder is sieved again to obtain the composite fluorescent ceramic powder.

[0095] The calcined powder is screened twice to remove any particulate impurities that may be present and ensure the purity and uniformity of the powder. After the second screening, fluorescent ceramic powder is obtained.

[0096] The fluorescent ceramic powder is statically pressed to form a semi-finished fluorescent ceramic product at a pressure of 50 MPa. The semi-finished fluorescent ceramic product is then placed in a vacuum and subjected to spark plasma sintering to form the finished fluorescent ceramic product. During the sintering process, the temperature in the furnace gradually increases, reaching a maximum sintering temperature of 1600°C, and the sintering temperature is maintained for 5 hours.

[0097] The fluorescent ceramic block is annealed in air at a temperature of 1000°C for 50 hours to eliminate the internal stress generated during the sintering process and improve the stability of the fluorescent ceramic. The fluorescent ceramic in this embodiment can also be ground, polished, cut and other processes.

[0098] Comparative Example 1

[0099] Comparative Example 1 provides a pure phase fluorescent ceramic with the general formula Y3Al5O 12 :Ce 3+ .

[0100] The above-mentioned pure phase fluorescent ceramic is prepared in the following manner:

[0101] According to Y3Al5O 12 :Ce 3+ The Y2O3 powder, Al2O3 powder and CeO2 powder were weighed in a stoichiometric ratio, which was the same as the commercially available Y3Al5O 12 :Ce 3+The phosphor particles remain consistent, for example, the Y:Al:Ce ratio can be 2.97:5:0.03. Y2O3 powder, Al2O3 powder, and CeO2 powder are mixed uniformly to form a mixed powder. During the mixing process, polyvinyl butyral and magnesium fluoride are added to promote uniform distribution of the powder and subsequent sintering. For example, the mass fraction of polyvinyl butyral in the mixed powder is 0.5%, and the mass fraction of magnesium fluoride in the mixed powder is 0.5%. The mixed powder is then dried and sieved to ensure that there are no large particles or impurities in the powder. After sieving, the powder is collected and set aside.

[0102] The sieved powder was placed in a high-temperature furnace for calcination at 700°C for 2 hours. The powder was sieved again to obtain a composite fluorescent ceramic powder.

[0103] The calcined powder is sieved twice to obtain fluorescent ceramic powder.

[0104] The fluorescent ceramic powder is dry-pressed at a pressure of 10 MPa to produce a semi-finished fluorescent ceramic product. The semi-finished fluorescent ceramic product is then placed in a vacuum and hot-pressed to form the finished fluorescent ceramic product. During the sintering process, the temperature in the furnace gradually increases, reaching a maximum temperature of 1400°C, and the sintering temperature is maintained for 10 hours.

[0105] The fluorescent ceramic block is annealed in air at 900°C for 2 hours to eliminate the internal stress generated during the sintering process and improve the stability of the fluorescent ceramic. The fluorescent ceramic in this embodiment can also be ground, polished, cut, and other processes.

[0106] Comparative Example 2

[0107] Comparative Example 2 provides a dual-phase fluorescent ceramic, the matrix ceramic phase can be alumina, and the fluorescent particle powder can be selected as Y3Al5O 12 :Ce 3+ Fluorescent particles.

[0108] The fluorescent ceramics are prepared as follows:

[0109] Weigh the commercially available Y3Al5O 12 :Ce 3+ Fluorescent particle powder and alumina powder, the volume ratio of fluorescent particle powder to alumina powder is 1:1, and Y3Al5O 12 :Ce 3+The fluorescent particle powder and alumina powder are evenly mixed to form a mixed powder. Appropriate amounts of polyvinyl butyral, magnesium fluoride, and polymethyl methacrylate are prepared. During the mixing process, polyvinyl butyral and magnesium fluoride are added to promote uniform distribution of the powders and facilitate subsequent sintering. For example, the mass fraction of polyvinyl butyral in the mixed powder is 0.5%, the mass fraction of magnesium fluoride is 0.5%, and the mass fraction of polymethyl methacrylate is 2%. The mixed powder is then dried and sieved to ensure that there are no large particles or impurities. After sieving, the powder is collected for later use.

[0110] The sieved powder is placed in a high-temperature furnace for calcination at 700°C for 2 hours. The powder is sieved again to obtain a composite fluorescent ceramic powder.

[0111] The calcined powder is sieved twice to obtain fluorescent ceramic powder.

[0112] The fluorescent ceramic powder is dry-pressed at a pressure of 10 MPa to produce a semi-finished fluorescent ceramic product. The semi-finished fluorescent ceramic product is then placed in a vacuum and hot-pressed to form the finished fluorescent ceramic product. During the sintering process, the temperature in the furnace gradually increases, reaching a maximum temperature of 1400°C, and the sintering temperature is maintained for 10 hours.

[0113] The fluorescent ceramic block is annealed in air at 900°C for 2 hours to eliminate the internal stress generated during the sintering process and improve the stability of the fluorescent ceramic. The fluorescent ceramic in this embodiment can also be ground, polished, cut, and other processes.

[0114] The relationship between the thermal conductivity, blue light absorption rate and fluorescence conversion rate of the fluorescent ceramic of Example 1 of the present application and Comparative Examples 1 and 2 is shown in Table 1:

[0115] Table 1 Comparison of fluorescent ceramic parameters of Example 1 and Comparative Examples 1 and 2

[0116]

[0117] As can be seen from Table 1, compared with the pure phase structure of comparative example 1 and the two-phase structure of comparative example 2, the thermal conductivity of the fluorescent ceramic of the ternary structure of Example 1 of the present application is higher. This is because compared with the pure phase fluorescent ceramic of comparative example 1, the high thermal conductivity of the matrix ceramic phase of the ternary structure fluorescent ceramic can further improve the heat dissipation performance of the fluorescent ceramic, thereby ensuring that the fluorescent ceramic can withstand higher power laser lighting. Compared with the two-phase fluorescent ceramic of comparative example 2, the ternary structure fluorescent ceramic adds the light scattering phase Gd 1.2 Zr2O 5.8Because the sintering temperature of the light-scattering phase is lower than that of the matrix ceramic phase, it aids sintering, thereby reducing the content of existing pores in the matrix ceramic phase and shrinking the size of the pores. This helps increase the density of the fluorescent ceramic and achieve higher thermal conductivity. The existing pores in the matrix ceramic phase refer to those existing due to the inability of the ceramic to fully densify, in addition to those introduced by the pore-forming agent. Furthermore, the increased thermal conductivity can enhance the thermal stability of the fluorescent particles, thereby achieving a higher excitation light power density threshold. The ternary structure fluorescent ceramic can exhibit higher reliability under high-power-density laser excitation.

[0118] At the same time, it can also be seen from Table 1 that the blue light absorption rate of the fluorescent ceramic of Example 1 of the present application is the same as that of Comparative Example 2, but higher than that of Comparative Example 1. In addition, the fluorescence extraction efficiency of the fluorescent ceramic of Example 1 of the present application is significantly higher than that of Comparative Examples 1 and 2. Therefore, the pores and light-scattering phases in the fluorescent ceramic of Example 1 can enhance blue light absorption and promote fluorescence conversion, thereby improving energy utilization.

[0119] The fluorescent ceramics, preparation methods, and light source devices provided in the embodiments of the present application utilize the difference in refractive index between the light-scattering phase and the pores and the fluorescent particles. When the excitation light propagates within the fluorescent ceramic, it will scatter at the interface between the light-scattering particles and the fluorescent particles, or when it enters the light-scattering particles or the fluorescent particles through the pores. The scattering phenomenon can change the path of the excitation light, increase the contact area between the excitation light and the fluorescent particles, and thus improve the efficient absorption and conversion of the excitation light, thereby improving the light conversion efficiency and light extraction efficiency of the fluorescent ceramic.

[0120] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A fluorescent ceramic, characterized in that: include: a matrix ceramic phase comprising a plurality of matrix particles; a fluorescent phase comprising a plurality of fluorescent particles dispersed in the matrix ceramic phase; a light scattering phase, the light scattering phase comprising a plurality of light scattering particles, the light scattering particles being dispersed in the matrix ceramic phase; Pores, at least some of which are dispersed at the interface of at least one of the matrix particles, the fluorescent particles, and the light scattering particles; as well as Wherein, the light scattering phase includes at least one structural formula A 2-x B2O 7-3x / 2 A compound wherein 0.1≤x≤1, A is selected from at least one of bismuth, indium, tin, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, and B is selected from at least one of manganese, vanadium, lead, titanium, zirconium and hafnium.

2. The fluorescent ceramic according to claim 1, characterized in that In the fluorescent ceramic, the refractive index of the light scattering phase at 632.8 nm is 1.9-2.

4.

3. The fluorescent ceramic according to claim 1, characterized in that: In the fluorescent ceramic, the refractive index of the fluorescent particles is greater than the refractive index of the pores and less than the refractive index of the light scattering particles.

4. The fluorescent ceramic according to claim 1, characterized in that At least a portion of the light scattering particles is in contact with the fluorescent particles, and at least a portion of the pores is in contact with at least one of the light scattering particles and the fluorescent particles.

5. The fluorescent ceramic according to any one of claims 1 to 4, characterized in that: In the fluorescent ceramic, the particle size of the light scattering particles is 0.4 μm-25 μm, and / or the volume proportion of the light scattering particles is 5%-20%.

6. The fluorescent ceramic according to any one of claims 1 to 4, characterized in that: In the fluorescent ceramic, the particle size of the fluorescent particles is 0.2 μm-30 μm, and / or the volume proportion of the fluorescent particles is 20%-50%.

7. The fluorescent ceramic according to any one of claims 1 to 4, characterized in that: The particle size of the matrix particles is 0.5 μm-20 μm, and / or the volume proportion of the matrix particles is 30%-45%.

8. The fluorescent ceramic according to any one of claims 1 to 4, characterized in that: In the fluorescent ceramic, the pores have a pore diameter of 0.1 μm-2 μm, and / or the volume of the pores accounts for 1%-15%.

9. A method for preparing fluorescent ceramics, characterized in that: include: Prepare light scattering particle powder, the light scattering particles include at least one structural formula A 2-x B2O 7-3x / 2 A compound of bismuth, indium, tin, yttrium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, and B is selected from at least one of manganese, vanadium, lead, titanium, zirconium and hafnium; Fluorescent particle powder and matrix particle powder are prepared, and the matrix particle powder, light scattering particle powder and fluorescent particle powder are mixed and calcined to form composite fluorescent ceramic powder. After the composite fluorescent ceramic powder is formed, it is sintered to form fluorescent ceramic.

10. A light source device, characterized in that: include: a light source, the light source emitting excitation light; as well as The fluorescent ceramic according to any one of claims 1 to 8, wherein the fluorescent ceramic is located in the optical path of the excitation light, and the fluorescent ceramic is used to convert the excitation light into converted light.

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