Phosphor for high power applications

Abstract

The present invention provides an improved luminescent composition for high power lighting applications. Provided is a phosphor ceramic including a garnet material having a composition of (A1-x-y-zCexTbyEuz) 3 (Al1-wGaw) 5O12, where A includes at least one selected from the group consisting of Y, Gd, La, Lu, Sc, and Sm; wherein 0 lt; x is less than or equal to 0.03, 0.2 lt; y is less than or equal to 0.9, and 0 lt; z < = 0.05, and x + y + z < = 1, and wherein 0 < = wlt; 1. Also provided is a method of making a phosphor ceramic comprising the steps of: a. Providing a garnet material of composition (A1-x-y-zCexTbyEuz) 3 (Al1-wGaw) 5O12 wherein A comprises at least one selected from the group consisting of Y, Gd, La, Lu, Sc and Sm; wherein 0 lt; x is less than or equal to 0.03, 0.2 lt; y is less than or equal to 0.9, and 0 lt; z < = 0.05, and x + y + z < = 1, and wherein 0 < = wlt; 1; b, forming the blank into a shape; and c. A shape formed by sintering.

Description

Technical Field

[0001] The present invention provides an improved luminescent composition for high-power lighting applications. Background Technology

[0002] For light intensity much higher than 1 W / mm 2 For high-power lighting applications, it is difficult to find suitable color conversion materials.

[0003] Not all materials are suitable for manufacturing the forms required to be compatible with high-power lighting devices. While common white LEDs use green and red phosphors in a resin matrix, resin is not a good thermal conductor and is prone to melting or degradation at high temperatures. Therefore, the heat generated in high-power applications makes this method unsuitable.

[0004] Some phosphor materials are simply not fast enough to handle high luminous flux. Furthermore, many materials may decompose and / or suffer severe temperature quenching due to the heat generated by the high light intensity. The limited number of suitable phosphors available for these devices not only restricts device performance but also slows market penetration for solid-state lighting applications in high-power applications.

[0005] One class of materials suitable for high-power applications is Ce-doped garnet phosphors in ceramic form (such as "YAG:Ce" or "LuAG:Ce"). These phosphors produce broadband yellow / green light emission, which can be used to generate cool white light. Compared to resins, ceramic materials have higher thermal stability and better thermal conductivity. However, while yellow / green light emission is feasible, finding compatible red light emitters has proven much more difficult. In fact, no red light-emitting ceramic materials are currently available, and the most common solution is to utilize the small amount of red light emitted by YAG:Ce. This is a very energy-inefficient method because it requires filtering out unwanted emission.

[0006] Other methods for achieving red light emission include Eu 2+ Doped nitride phosphors. However, under high light intensity, photothermal quenching leads to a very low quantum yield. Furthermore, the material degrades rapidly due to the generated heat. Moreover, Eu... 2+ Doped nitride phosphors cannot bond with YAG:Ce ceramics. To overcome these issues, a phosphor-in-glass approach has been explored, in which powdered phosphors are suspended within a glass matrix. While glass offers higher thermal stability than resin, its thermal conductivity is lower than that of ceramics. Furthermore, this method results in a lower phosphor packing density, leading to weaker emission.

[0007] US2019 / 0367809 discloses a fluorescent powder material and a light-emitting device.

[0008] Therefore, there is still a need for red-emitting phosphor materials for high-power applications. Attached Figure Description

[0009] Figure 1 The emission spectrum of the YAG:Ce,Tb,Eu phosphor discussed in Example 1 is shown. Excitation was performed at 450 nm.

[0010] Figure 2 The emission spectrum of the LuAG:Ce,Tb,Eu phosphor discussed in Example 2 is shown. Excitation was performed at 450 nm.

[0011] Figure 3 The emission spectrum of the YAGG:Ce,Tb,Eu phosphor discussed in Example 3 is shown. Excitation was performed at 450 nm.

[0012] Figure 4 The emission spectrum of the LuAGG:Ce,Tb,Eu phosphor discussed in Example 4 is shown. Excitation was performed at 450 nm.

[0013] Figure 5 The emission spectrum of the YAGG:Ce,Tb,Eu and LuAGG:Ce phosphor mixture discussed in Example 5 is shown. Excitation was performed at 450 nm.

[0014] Figure 6 The simulated emission spectrum of the LuAG:Ce, YAG:Eu and 450 nm pumped LED combination is shown, with a CCT of 6000 K and a CRI of 87, as discussed in Example 7.

[0015] Figure 7 The simulated emission spectrum of the LuAG:Ce, YAG:Eu and 450 nm pumped LED combination is shown, with a CCT of 3000 K and a CRI of 79, as discussed in Example 7.

[0016] Figure 8 The simulated emission spectrum of the YAG:Ce, YAG:Eu and 450 nm pumped LED combination is shown, with a CCT of 3000 K and a CRI of 68, as discussed in Example 7.

[0017] Figure 9 The emission spectrum of Example 8 is shown, with a CCT of 3112 K and a CRI of 66.

[0018] Figure 10 The emission spectrum of Example 9 is shown, with a CCT of 5575 K and a CRI of 80. Summary of the Invention

[0019] There is provided a phosphor ceramic comprising a garnet material having the composition (A 1-x-y-z Ce x Tb y Eu z )3(Al 1-w Ga w )5O 12 , wherein A comprises at least one selected from Y, Gd, La, Lu, Sc, and Sm; wherein 0 < x ≤ 0.03, 0.2 < y ≤ 0.9, and 0 < z ≤ 0.05, and x + y + z ≤ 1, and wherein 0 ≤ w < 1.

[0020] It has been found that phosphor ceramics are particularly suitable for high-power applications requiring high-quality (color rendering index higher than 70) white light due to the combination of yellow / green and red emitters. In addition, due to the doping ions being in a single material, the phosphors are more evenly dispersed. The ceramic form is a good thermal conductor, thus preventing thermal quenching and degradation of the phosphors. The combination of efficient light conversion and reduced thermal quenching results in higher energy efficiency of the phosphor ceramics.

[0021] There is also provided a method for manufacturing such phosphor ceramics, which comprises the steps of a phosphor ceramic manufacturing method, including the following steps: a. Providing a garnet material having the composition (A 1-x-y-z Ce x Tb y Eu z )3(Al 1-w Ga w )5O 12 , wherein A comprises at least one selected from Y, Gd, La, Lu, Sc, and Sm; wherein 0 < x ≤ 0.03, 0.2 < y ≤ 0.9, and 0 < z ≤ 0.05, and x + y + z ≤ 1; and wherein 0 ≤ w < 1; b. Shaping it into a shape; and c. Sintering the shaped shape.

[0022] This method can manufacture high-quality phosphor ceramics in a simple manner. Detailed Description

[0023] The term "phosphor" according to the present invention particularly refers to or includes the following materials: which emit light upon appropriate excitation, preferably upon excitation in the blue, violet, UV-A, or UV-B range (i.e., especially 280 - 490 nm), especially light in the wavelength range of 400 - 2500 nm (visible and infrared spectra).

[0024] The term "phosphor ceramic" according to the present invention particularly refers to a ceramic substantially composed of a luminescent material.

[0025] The term "ceramic" according to the present invention particularly refers to and / or includes a dense crystalline or polycrystalline material, which includes a controllable amount of pores or is pore-free.

[0026] The term "polycrystalline material" according to the present invention particularly refers to and / or includes the following materials: the bulk density of its main component is greater than 90%, it is composed of more than 80% of individual crystal domains, the diameter of each crystal domain is 0.01 - 150 µm, and it has different crystallographic orientations. The individual crystal domains can be combined with each other, or diluted by an amorphous or vitreous material or by an additional crystal phase.

[0027] There is provided a phosphor ceramic, which includes a garnet material having the composition (A 1-x-y-z Ce x Tb y Eu z )3(Al 1-w Ga w )5O 12 , where 0 < x ≤ 0.03, 0.2 < y ≤ 0.9, and 0 < z ≤ 0.05, and x + y + z ≤ 1; and where 0 ≤ w < 1. A includes at least one selected from Y, Gd, La, Lu, Sc, and Sm. Therefore, the composition of the garnet material is A3Al5O 12 garnet, where A is partially replaced by Ce, Tb, and Eu; and Al can be partially replaced by Ga.

[0028] Preferably, A is Y and / or Lu.

[0029] The doping amount x of Ce is greater than 0 and equal to or less than 0.03. Low Ce doping may result in insufficient Ce emission to absorb the required proportion of excitation light, so preferably x is greater than or equal to 0.0005. High Ce doping may result in metal-to-metal charge transfer quenching between Ce and Eu, thus reducing the quantum yield. High Ce doping may also result in back transfer from Tb to Ce. Therefore, x is preferably less than or equal to 0.003. Preferably, 0.0005 ≤ x ≤ 0.003.

[0030] The doping amount y of Tb is greater than 0.2 and equal to or less than 0.9. In addition to exhibiting good emission properties of the desired color, Tb also enhances the energy transfer from Ce to Eu. Therefore, y is preferably greater than or equal to 0.3. Too much Tb can lead to reverse transfer from Tb to Ce and reduce the quantum yield due to concentration quenching. Therefore, it is preferred that y is less than or equal to 0.85. Preferably, 0.3 ≤ y ≤ 0.85.

[0031] The doping amount z of Eu is greater than 0 and equal to or less than 0.05. Eu emits red light and is thus crucial for generating warm white light. Therefore, z is preferably equal to or greater than 0.001. High Eu doping can lead to metal-metal charge transfer quenching between Ce and Eu, thereby reducing the quantum yield. Therefore, it is preferred that z is equal to or less than 0.01. Preferably, 0.001 ≤ z ≤ 0.01.

[0032] The total doping amount cannot exceed 1. It has been found that using these dopants in these ratios can achieve good conversion rates and good color properties in high-power applications.

[0033] The doping amount w of Ga is equal to or greater than 0 and less than 1. It has been found that the introduction of Ga can increase the emission of Eu and reduce the emission of Ce by reducing the reverse transfer from Tb to Ce, which can improve the color properties. Preferably, 0.2 ≤ w ≤ 0.6.

[0034] In one embodiment, the phosphor ceramic comprises a second garnet material having the composition ((Y,Lu) 1-a (Ce) a )3(Al (1-b) Ga b )5O 12 , where 0 < a ≤ 0.02; and 0 ≤ b < 1. Therefore, the composition of the second garnet material is (Y,Lu)3Al5O 12 garnet, partially doped with cerium at the Y, Lu positions, and where aluminum can be partially replaced by Ga. The second garnet material includes only Ce as its emitting ion, which allows adjustment of the cerium emission intensity of the final phosphor ceramic. Since the properties of the first garnet material and the second garnet material are similar, they can be easily combined into a single ceramic.

[0035] The doping amount a of Ce in the second garnet material is greater than 0 and equal to or less than 0.02. Preferably, 0.0005 ≤ a ≤ 0.01. The doping amount b of Ga is equal to or greater than 0 and less than 1. Preferably, 0 ≤ b ≤ 0.6.

[0036] The phosphor ceramic is preferably a translucent ceramic, and the percentage in-line transmittance of a 0.2 mm ceramic sample measured using a two-beam spectrophotometer in visible light (e.g., 420-700 nm) is less than about 50%. Preferably, for a 0.2 mm ceramic sample, the in-line transmittance is about 0%-20%. This translucency originates from scattering within the ceramic.

[0037] Furthermore, phosphor ceramics showed performance at 1 W / mm² for ceramic samples with a thickness of 0.2 mm. 2 The quantum yield measured under 450 nm light irradiation is at least 60%, preferably greater than 70%, and more preferably greater than 80%.

[0038] Phosphorescent ceramics may also include any optical ceramic additives known in the art. Preferably, the additives are selected from scattering aids, thermal conductivity enhancers, or fluxes. More preferably, the additives are selected from alumina, silica, and magnesium oxide. These additives have extremely high thermal conductivity, thus improving the overall thermal conductivity of the ceramic. High thermal conductivity allows the ceramic to operate at lower temperatures under device conditions, resulting in better conversion efficiency. Furthermore, they can also act as fluxes during ceramic sintering. Preferably, the phosphorescent ceramic includes about 0.5 wt% or less silica. At this content, silica helps achieve higher densification in conventional garnet ceramics. Alumina can also improve scattering, thus functioning as a scattering aid.

[0039] The bulk density of phosphor ceramics is preferably greater than 90% of the theoretical maximum density, as measured at room temperature using an electronic densitometer (MD-300s) equipped with an Alfa Mirage balance, utilizing Archimedes' principle and water as the buoyant liquid. High density is desirable for both thermal conductivity and ceramic strength.

[0040] Preferably, the phosphor ceramic has a thickness of ≥0.1 mm to ≤2.0 mm. Thickness is defined as the shortest distance through the phosphor ceramic. These dimensions are suitable for use in light-emitting devices because this is typically the thickness required to achieve the desired wavelength conversion ratio. Within this dimension, the phosphor ceramic exhibits good optical properties. In one embodiment, the phosphor ceramic is a flat plate shape with a diameter-to-thickness ratio greater than 5:1.

[0041] Preferably, the phosphor ceramic is a polycrystalline material composed of more than 80% by weight of single crystal domains, each with a diameter of less than about 150 μm and greater than about 10 nm.

[0042] Preparation method A method for manufacturing phosphor ceramics is provided, comprising the following steps: a. Provides a composition of (A)1-x-y-z Ce x Tb y Eu z )3(Al 1-w Ga w )5O 12 A garnet material, where A includes at least one selected from Y, Gd, La, Lu, Sc, and Sm; where 0 < x ≤ 0.03, 0.2 < y ≤ 0.9, and 0 < z ≤ 0.05, and x + y + z ≤ 1; and where 0 ≤ w < 1; b. Shaping the garnet material into a shape; and c. Sintering the shaped shape.

[0043] This method can prepare the phosphor ceramics of the present invention.

[0044] Step a. includes providing a composition of (A 1-x-y-z Ce x Tb y Eu z )3(Al 1-w Ga w )5O 12 A garnet material, where A includes at least one selected from Y, Gd, La, Lu, Sc, and Sm; where 0 < x ≤ 0.03, 0.2 < y ≤ 0.9, and 0 < z ≤ 0.05, and x + y + z ≤ 1; and where 0 ≤ w < 1.

[0045] In one embodiment, step a. includes providing a composition of ((Y,Lu) 1-a (Ce) a )3(Al (1-b) Ga b )5O 12 Another garnet material, where 0 < a ≤ 0.02, preferably 0.0005 ≤ a ≤ 0.01; and 0 ≤ b < 1, preferably 0 ≤ b < 0.6.

[0046] In one embodiment, the garnet material is in the form of particles with a diameter less than about 10 microns and greater than about 100 nm; and / or the other garnet material is in the form of particles with a diameter less than about 10 microns and greater than about 100 nm. Such particles are easy to obtain and allow for the desired grain size and opacity.

[0047] In one embodiment, the garnet material is in the form of particles with a diameter less than about 100 nm and greater than about 2 nm; and / or the other garnet material is in the form of particles with a diameter less than about 100 nm and greater than about 2 nm. Using nanoparticles allows the garnet material to be more easily mixed, reduces the sintering temperature, and obtains a higher density.

[0048] Step b. includes shaping the garnet material into a form. Step b. can include any known method of shaping the garnet material into a form. For example, step b. can include axial and / or cold isostatic pressing, tape casting, slot die molding, and / or thermoplastic processes (e.g., injection molding, hot casting (low or medium pressure injection molding), and / or extrusion). Preferably, step b. is carried out such that the compression process is performed at a pressure >20 and <200 MPa.

[0049] Step c. includes sintering to form the desired shape. This step allows ceramics to be formed from garnet material. Preferably, the sintering involves heating at a temperature of 1200-1800°C for 4-6 hours. When the garnet material and / or another garnet material is in the form of particles with a diameter less than about 10 micrometers and greater than about 100 nanometers, the sintering preferably includes heating at a temperature of 1400-1800°C for 4-6 hours, more preferably at about 1600°C for about 4 hours. When the garnet material and / or another garnet material is in the form of particles with a diameter less than about 100 nm and greater than about 2 nm, the sintering preferably includes heating at a temperature of 1200-1600°C for 4-6 hours, more preferably at about 1500°C for about 4 hours. Preferably, the sintering is carried out at 10... -3 It is carried out in a low-pressure atmosphere of mbar or lower.

[0050] The method may also include recompressing the sintered ceramic by hot isostatic pressing, and / or reprocessing the sintered ceramic, particularly by ion beam preparation processes or by machining or fine grinding processes using specific or non-specific cutting edges. When hot isostatic pressing is performed, it is preferably carried out such that the recompression is carried out at a pressure >120 and <180 MPa, preferably >140 and <160 MPa.

[0051] The method preferably also includes heating and sintering the ceramic in an air atmosphere at 1000°C-1300°C. This post-annealing prevents the sintered body from becoming too dark.

[0052] This method has proven useful because it allows for the easy fabrication of suitable phosphor ceramics in most applications.

[0053] A light-emitting device is also provided. The light-emitting device includes the phosphor ceramic of the present invention.

[0054] Preferably, the light-emitting device further includes an emission intensity of at least 1 W / mm². 2 Light-emitting diodes or laser diodes. It has been found that the phosphor ceramics of this invention perform well under such high-power conditions.

[0055] Preferably, the light-emitting diode or laser diode emits UV-A, violet, or blue light. These wavelengths are suitable for exciting Ce in the phosphor ceramic. 3+ More preferably, the light-emitting diode or laser diode emits blue light, which allows for a combination of blue light emission and converted light emission, thereby achieving good color rendering in a highly efficient manner.

[0056] The phosphor ceramics according to the present invention can be used in various specific topologies or applications, including but not limited to the following: 1. "Directly deposited phosphorescent ceramics": Phosphor ceramics are applied directly onto LED chips (dice) in thin sheets, sometimes using intermediate bonding materials such as silicone, sol-gel, or glass.

[0057] 2. "Remote Phosphorescent" System: A "remote phosphor" system specifically refers to a device in which the phosphor is positioned away from a light source emitting a narrow wavelength range. The phosphor is typically embedded in or attached to a polymer, glass, or ceramic matrix. Therefore, a remote phosphor system differs fundamentally from a system where the phosphor is directly applied to or at the light source, such as an LED light source where the phosphor is directly applied to the LED chip. Generally, there are two basic structures, from which many variations are derived: a) "Remote phosphor in transmission applications": The phosphor matrix is ​​placed on a reflective cavity in which the LED is located. Light can escape only through the phosphor matrix (transmission); b) "Remote phosphor in reflective applications": The phosphor matrix is ​​applied to a reflective carrier or coated with a reflective material on its back. The LED light source is located inside or slightly off-center in the emission direction and illuminates the phosphor matrix. The converted light is re-emitted in the direction of the light source or the illumination direction. The light passing through the phosphor matrix passes through the back reflective layer again in the emission direction through the phosphor matrix. Therefore, light can escape only in the reflection direction. According to a preferred embodiment of the invention, in the light-emitting system of the present invention, the ceramic phosphor can be optically coupled to the LED chip. These types of LED chips can be based on III-V nitride material systems. For example, an LED chip may include a GaInN-based active region located between n-type and p-type GaN layers, the GaN layers being deposited on a suitable substrate (e.g., sapphire, silicon carbide, silicon, Ga2O3, or GaN itself) using known methods such as metal-organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). Optical coupling from the LED active region to the ceramic phosphor can be achieved via the substrate (in the case of a transparent substrate and flip-chip mounting structure) or an epitaxial layer (in the case of substrate-down mounting, or in the case where the substrate has been removed in a thin-film flip-chip LED architecture). The ceramic phosphor can be physically attached to the LED chip, typically using a transparent adhesive such as silicone.

[0058] Alternatively, the ceramic phosphor can be mounted away from the LED chip. Optical materials are provided to help direct and / or mix the primary light from the LED chip and the light emitted by the ceramic phosphor. For example, a reflective material (such as titanium dioxide) can be loaded onto silicone and applied around the sides of the LED chip and the ceramic phosphor, such that almost all light emission passes through the top surface of the ceramic phosphor. This improves brightness and homogenizes color uniformity.

[0059] LED chips can be mounted in packages, such as ceramic packages or leadframe-based packages, to provide mechanical stability and / or handling capability, as well as heat dissipation. Furthermore, the package can provide a platform for the application of lenses surrounding the LED chip, which includes a ceramic phosphor. Such lenses can be made of transparent silicone and have a dome-shaped form, facilitating light output coupling from the ceramic phosphor. Current is supplied to the LED chip through electrodes within the package, which are electrically connected to ohmic contact materials applied to the n-type and p-type layers within the LED chip. A portion of this current is converted into light generation within the LED's active region. Depending on the detailed design of the LED's active region, the primary emission wavelength range can be tuned. For example, for GaInN, this range, with tenability, can be from UV-A to the entire visible spectrum. Specifically, the primary emission wavelength can be selected to interact with the ceramic phosphor in a desirable manner, for example, providing emitted light with a certain chromaticity and certain color rendering properties.

[0060] One or more LEDs in the aforementioned package, comprising an LED chip and a ceramic phosphor, can be used as part of a lighting system. Such a lighting system can be a lighting module, a lamp, or a luminaire. A lighting module may include multiple packaged LEDs and additional means for light modulation (optics) and thermal management (passive or active cooling). Optionally, the module may also include an electrical drive for supplying target current and voltage levels to the LEDs from a primary mains or battery power source. Lamps are typically molded in a standard housing and, in addition to the LEDs, typically include an electrical drive for connection to the mains power source via a standard socket interface. Similarly, luminaires have a housing and, in addition to the LEDs, typically include an electrical drive for connection to the mains power source. Furthermore, sensing and / or communication devices may be included in the lighting system.

[0061] The use of the phosphor ceramics of the present invention in high-power applications is also provided. It has been found that the phosphor ceramics of the present invention benefit from improved Eu... 3+ Its emission and thermal conductivity are good for these high-power applications.

[0062] This invention may also be defined in the following clauses: 1. A phosphorescent ceramic comprising (A) 1-x-y-z Ce x Tb y Eu z )3(Al 1-w Ga w )5O 12a garnet material, wherein A comprises at least one selected from Y, Gd, La, Lu, Sc, and Sm; where 0 < x ≤ 0.03, 0.2 < y ≤ 0.9, and 0 < z ≤ 0.05, and x + y + z ≤ 1, where 0 ≤ w < 1.

[0063] 2. The phosphor ceramic in any of the preceding clauses, wherein 0.0005 ≤ x ≤ 0.003, 0.3 ≤ y ≤ 0.85, and / or 0.001 ≤ z ≤ 0.01.

[0064] 3. The phosphor ceramic in any of the preceding clauses, wherein A comprises Y and / or Lu.

[0065] 4. The phosphor ceramic in any of the preceding clauses, which further comprises a second garnet material having the composition ((Y,Lu) 1-a (Ce) a )3(Al( 1-b )Ga b )5O 12 ) where 0 < a ≤ 0.02, preferably 0.0005 ≤ a ≤ 0.01; and 0 ≤ b < 1.

[0066] 5. The phosphor ceramic in any of the preceding clauses, wherein 0.2 ≤ w ≤ 0.6, and / or wherein 0 ≤ b ≤ 0.6.

[0067] 6. The phosphor ceramic in any of the preceding clauses, which: - is a translucent ceramic, and its linear transmittance %T at a thickness of 0.2 mm is less than about 50%, preferably about 0 to about 20%; - its quantum yield measured under 450 nm light irradiation at 1 W / mm 2 for a ceramic sample with a thickness of 0.2 mm is at least 60%, preferably greater than 70%, more preferably greater than 80%; - its volume density is greater than 90% of the theoretical maximum density; and / or - further contains one or more additives selected from scattering aids, thermal conductivity enhancers, and fluxes, preferably, wherein the additives are selected from alumina, silica, or magnesia.

[0068] 7. The phosphor ceramic according to clause 6, having a thickness of ≥ 0.1 mm to ≤ 2.0 mm.

[0069] 8. The phosphor ceramic in any of the preceding clauses, which is a polycrystalline material composed of more than 80 wt% of a single crystal domain, and the diameter of each domain is less than about 150 µm and greater than about 10 nm.

[0070] 9. A method for manufacturing a phosphor ceramic, comprising the following steps: a. Providing a garnet material having a composition of (A 1-x-y-z Ce x Tb y Eu z )3(Al 1-w Ga w )5O 12 , wherein A comprises at least one selected from Y, Gd, La, Lu, Sc, and Sm; wherein 0 < x ≤ 0.03, 0.2 < y ≤ 0.9, and 0 < z ≤ 0.05, and x + y + z ≤ 1; and wherein 0 ≤ w < 1; b. Shaping it into a shape; and c. Sintering the shaped shape.

[0071] 10. The method according to clause 7, wherein step a comprises providing another garnet material having a composition of ((Y,Lu) 1-a (Ce) a )3(Al( 1-b )Ga b )5O 12 ), wherein 0 < a ≤ 0.02, preferably 0.0005 ≤ a ≤ 0.01; and 0 ≤ b < 1, preferably 0 ≤ b < 0.6.

[0072] 11. The method according to clause 9 or 10, wherein the garnet material is in the form of particles having a diameter less than about 10 microns and greater than about 100 nm; and / or the another garnet material is in the form of particles having a diameter less than about 10 microns and greater than about 100 nm.

[0073] 12. The method according to clause 9 or 10, wherein the garnet material is in the form of particles having a diameter less than about 100 nm and greater than about 2 nm; and / or the another garnet material is in the form of particles having a diameter less than about 100 nm and greater than about 2 nm.

[0074] 13. The method according to any one of clauses 9 - 12, wherein step b. comprises axial and / or cold isostatic pressing, tape casting, slit die pressing process, and / or thermoplastic process (such as injection molding, hot casting (low pressure or medium pressure injection molding), and / or extrusion), wherein preferably step b. is carried out such that the compression process is carried out at a pressure greater than 20 and less than 200 MPa.

[0075] 14. The method according to any one of clauses 9 - 13, wherein c. comprises heating at a temperature of 1200 - 1800 °C for 4 - 6 hours, preferably at 10 -3It is carried out in a low-pressure atmosphere of mbar or lower.

[0076] 15. The method according to Clause 14, wherein the garnet material and / or another garnet material are in the form of particles with a diameter less than about 10 micrometers and greater than about 100 nm, and the sintering comprises heating at a temperature of 1400-1800°C for 4-6 hours, preferably heating at about 1600°C for about 4 hours.

[0077] 16. The method according to Clause 14, wherein the garnet material and / or another garnet material are in the form of particles with a diameter less than about 100 nm and greater than about 2 nm, and the sintering preferably includes heating at a temperature of 1200-1600°C for 4-6 hours, preferably heating at about 1500°C for about 4 hours.

[0078] 17. The method according to any one of clauses 9-16 further includes ceramics sintered by heating in an air atmosphere at 1000°C-1300°C.

[0079] 18. A light-emitting device comprising the phosphor ceramic of items 1-8, preferably further comprising an emission intensity of at least 1 W / mm². 2 Light-emitting diodes or laser diodes.

[0080] 19. The light-emitting device according to Clause 18, wherein the light-emitting diode or laser diode emits UV-A or blue light.

[0081] 20. Use of phosphor ceramic materials in high-power applications as described in Clauses 1-8.

[0082] Example Comparative Example A: Ce 3+ , Tb 3+ Co-doped YAG Weigh 0.27 g of yttrium nitrate hydrate, 1.875 g of aluminum nitrate hydrate, 0.0013 g of cerium nitrate hydrate, 1.00 g of terbium nitrate hydrate, and 0.6 g of urea to prepare a YAG:0.1%Ce, 76.8%Tb phosphorescent powder. Dissolve all chemicals in 5 mL of deionized water. Then heat the solution to boiling until a foamy substance is obtained. Grind the foam and transfer it to an alumina crucible. Bake in air at 1000°C for 2 hours. Grind the sample again and bake in air at 1500°C for 4 hours. A yellow powder sample is obtained.

[0083] Ce, Tb co-doped YAG exhibits broad Ce emission under 450 nm excitation. Due to Tb... 3+ →Ce 3+ The energy was reversed, and the emission did not show any Tb peak.

[0084] Example 1: Ce 3+ , Tb 3+ Eu 3+ Co-doped YAG Weigh 0.265 g of yttrium nitrate hydrate, 1.875 g of aluminum nitrate hydrate, 0.0013 g of cerium nitrate hydrate, 1.00 g of terbium nitrate hydrate, 0.0027 g of europium nitrate hydrate, and 0.6 g of urea to prepare a YAG:0.1%Ce, 76.8%Tb, 0.2%Eu phosphorescent powder. Dissolve all chemicals in 5 mL of deionized water. Then heat the solution to boiling until a foamy substance is obtained. Grind the foam and transfer it to an alumina crucible. Bake in air at 1000°C for 2 hours. Grind the sample again and bake in air at 1500°C for 4 hours. A yellow powder sample is obtained.

[0085] Ce, Tb, Eu co-doped YAG exhibits broad Ce emission combined with strong Eu line emission under 450 nm excitation. Figure 1 ).

[0086] Example 2: Ce 3+ , Tb 3+ Eu 3+ Co-doped LuAG Weigh 0.30 g of lutetium nitrate hydrate, 1.875 g of aluminum nitrate hydrate, 0.0013 g of cerium nitrate hydrate, 1.00 g of terbium nitrate hydrate, 0.0027 g of europium nitrate hydrate, and 0.6 g of urea to prepare a LuAG:0.1%Ce, 76.8%Tb, 0.2%Eu phosphorescent powder. Dissolve all chemicals in 5 mL of deionized water. Then heat the solution to boiling until a foamy substance is obtained. Grind the foam and transfer it to an alumina crucible. Bake in air at 1000°C for 2 hours. Grind the sample again and bake in air at 1500°C for 4 hours. A yellow powder sample is obtained.

[0087] Ce, Tb, Eu co-doped LuAG exhibits broad Ce emission combined with strong Eu line emission under 450 nm excitation. Figure 2 ).

[0088] Example 3: Ce 3+ , Tb 3+ Eu 3+ Co-doped YAGG Weigh 0.265 g of yttrium nitrate hydrate, 1.032 g of aluminum nitrate hydrate, 0.94 g of gallium nitrate hydrate, 0.0013 g of cerium nitrate hydrate, 1.00 g of terbium nitrate hydrate, 0.0027 g of europium nitrate hydrate, and 0.6 g of urea to prepare a YAGG:0.1%Ce, 76.8%Tb, 0.2%Eu phosphorescent powder with 45% gallium at aluminum sites. Dissolve all chemicals in 5 mL of deionized water. Then heat the solution to boiling until a foamy substance is obtained. Grind the foam and transfer it to an alumina crucible. Bake in air at 1000°C for 2 hours. Grind the sample again and bake in air at 1500°C for 4 hours. Obtain a yellow powder sample.

[0089] Ce, Tb, Eu co-doped YAGG exhibits strong Eu line emission under 450 nm excitation. Figure 3 Since most of the energy is transferred to Eu through the Tb intermediate, the broad Ce emission is very weak.

[0090] Example 4: Ce 3+ , Tb 3+ Eu 3+ Co-doped LuAGG Weigh 0.30 g of yttrium nitrate hydrate, 1.032 g of aluminum nitrate hydrate, 0.94 g of gallium nitrate hydrate, 0.0013 g of cerium nitrate hydrate, 1.00 g of terbium nitrate hydrate, 0.0027 g of europium nitrate hydrate, and 0.6 g of urea to prepare a LuAGG:0.1%Ce, 76.8%Tb, 0.2%Eu phosphorescent powder with 45% gallium at aluminum sites. Dissolve all chemicals in 5 mL of deionized water. Then heat the solution to boiling until a foamy substance is obtained. Grind the foam and transfer it to an alumina crucible. Bake in air at 1000°C for 2 hours. Grind the sample again and bake in air at 1500°C for 4 hours. Obtain a yellow powder sample.

[0091] Ce, Tb, Eu co-doped LuAGG exhibits strong Eu line emission under 450 nm excitation ( Figure 4 Since all energy is transferred to Eu through the Tb intermediate, the broad Ce emission disappears.

[0092] Example 5: Ce 3+ , Tb 3+ Eu 3+ Co-doped YAGG-Ce 3+ LuAGG-doped mixed phosphors Following the above process, a YAGG:0.1%Ce, 60%Tb, 0.2% Eu phosphor powder with 20% gallium at aluminum sites was prepared. Similarly, a LuAGG:0.5%Ce phosphor powder with 20% gallium at aluminum sites was prepared. The Ce, Tb, Eu co-doped YAGG exhibited broad Ce emission and strong Eu line emission under 450 nm excitation. The Ce-doped LuAGG exhibited broad blue-green light emission under 450 nm excitation. The Ce, Tb, Eu co-doped YAGG and Ce-doped LuAGG phosphors were mixed in a 5:1 ratio. The emission of the mixed phosphors covered the wide spectral range required to achieve high CRI white LED emission. Figure 5 ).

[0093] Example 6: Hybrid Phosphorite Ceramics The Ce, Tb, Eu co-doped YAGG and Ce-doped LuAGG phosphor mixture prepared in Example 5 was mixed with TEOS to achieve a final silica content of approximately 1%. The powder was uniaxially pressed under a 10-ton load to form sheets (thickness ~0.5 mm). The sheets were then annealed at 1400°C for 4 hours in a nitrogen atmosphere to obtain a mixed phosphor ceramic. The emission spectrum of the sheets obtained in this example exhibits similar spectral profiles to the phosphor powder described in Example 5. Figure 5 ).

[0094] Example 7: Simulated Spectrum The emission spectrum obtained in Example 4 was combined with the emission spectra of LuAGG:Ce and YAG:Ce from Example 5 (obtained by measuring a commercially available YAG:Ce (3%) sample) and the emission spectrum of a 450 nm LED to obtain a simulated spectrum.

[0095] In the first simulation, the spectrum of Example 4, the emission spectrum of LuAG:Ce, and the emission spectrum of a 450 nm LED were combined to achieve a CCT of 6000 K. The combined simulated spectrum showed a CRI of 87 (…). Figure 6 ).

[0096] In the second simulation, the spectrum from Example 4, the emission spectrum of LuAG:Ce, and the emission spectrum of a 450 nm LED were combined to achieve a CCT of 3000 K. The combined simulated spectrum showed a CRI of 79 (…). Figure 7 ).

[0097] In the third simulation, the spectrum from Example 4, the emission spectrum of YAG:Ce, and the emission spectrum of a 450 nm LED were combined to achieve a CCT of 3000 K. The combined simulated spectrum showed a CRI of 68 (…). Figure 8 ).

[0098] Example 8: LED Spectrum The material from Example 4 was mixed with LuAG:Ce and incorporated into silica gel. Then, droplets were placed on a 450 nm LED chip, and their thickness was adjusted until the spectrum fell on the blackbody line of the CIE 1931 xy chromaticity diagram. This spectrum showed a correlated color temperature of 3112 K and a CRI of 66 (…). Figure 9 ).

[0099] Example 9: LED Spectrum The mixed phosphor material from Example 5 was incorporated into silica gel. Then, droplets were placed on a 450 nm LED chip, and their thickness was adjusted until the spectrum fell on the blackbody line of the CIE 1931 xy chromaticity diagram. This spectrum showed a correlated color temperature of 5575 K and a CRI of 80 (…). Figure 10 ).

Claims

1. A phosphor ceramic comprising (A) 1-x-y-z Ce x Tb y Eu z )3(Al 1-w Ga w )5O 12 Garnet material, wherein A includes at least one selected from Y, Gd, La, Lu, Sc and Sm; where 0 < x ≤ 0.03, 0.2 < y ≤ 0.9, and 0 < z ≤ 0.05, and x + y + z ≤ 1, where 0 ≤ w < 1.

2. The phosphor ceramic according to any one of the preceding claims, where 0.0005 ≤ x ≤ 0.003, 0.3 ≤ y ≤ 0.85, and / or 0.001 ≤ z ≤ 0.

01.

3. The phosphor ceramic according to any one of the preceding claims, where A comprises Y and / or Lu.

4. The phosphor ceramic according to any one of the preceding claims, further comprising a second garnet material having a composition of ((Y,Lu) 1-a (Ce) a )3(Al( 1-b )Ga b )5O 12 ), where 0 < a ≤ 0.02, preferably 0.0005 ≤ a ≤ 0.01; and 0 ≤ b < 1.

5. The phosphor ceramic according to any one of the preceding claims, where 0.2 ≤ w ≤ 0.6, and / or where 0 ≤ b ≤ 0.

6.

6. The phosphor ceramic according to any one of the preceding claims, which: - is a translucent ceramic with a linear transmittance %T of less than about 50%, preferably about 0 to about 20%, when the thickness is 0.2 mm; - Its performance on ceramic samples with a thickness of 0.2 mm at 1 W / mm 2 The quantum yield measured under 450 nm light irradiation is at least 60%, preferably greater than 70%, and more preferably greater than 80%; - has a bulk density greater than 90% of the theoretical maximum density; and / or - further comprises one or more additives selected from scattering aids, thermal conductivity enhancers, and fluxes, preferably where the additives are selected from alumina, silica, or magnesia.

7. The phosphor ceramic according to claim 6, having a thickness of ≥ 0.1 mm to ≤ 2.0 mm.

8. The phosphor ceramic according to any one of the preceding claims, which is a polycrystalline material composed of more than 80% by weight of a single crystal domain, with the diameter of each crystal domain being less than about 150 µm and greater than about 10 nm.

9. A method for manufacturing a phosphor ceramic, which comprises the following steps: a. Provide a garnet material having a composition of (A 1-x-y-z Ce x Tb y Eu z )3(Al 1-w Ga w )5O 12 , wherein A comprises at least one selected from Y, Gd, La, Lu, Sc, and Sm; wherein 0 < x ≤ 0.03, 0.2 < y ≤ 0.9, and 0 < z ≤ 0.05, and x + y + z ≤ 1; and wherein 0 ≤ w < 1; b. shaping it into a shape; and c. sintering the shaped form.

10. The method according to claim 7, wherein step a comprises providing another garnet material having a composition of ((Y, Lu) 1-a (Ce) a )3(Al( 1-b )Ga b )5O 12 ), where 0 < a ≤ 0.02, preferably 0.0005 ≤ a ≤ 0.01; and 0 ≤ b < 1, preferably 0 ≤ b < 0.

6.

11. The method according to claim 9 or 10, where the garnet material is in the form of particles with a diameter less than about 10 microns and greater than about 100 nm; and / or the other garnet material is in the form of particles with a diameter less than about 10 microns and greater than about 100 nm.

12. The method according to claim 9 or 10, where the garnet material is in the form of particles with a diameter less than about 100 nm and greater than about 2 nm; and / or the other garnet material is in the form of particles with a diameter less than about 100 nm and greater than about 2 nm.

13. A light-emitting device comprising the phosphor ceramic of claims 1-8, preferably further comprising an emission intensity of at least 1 W / mm². 2 Light-emitting diodes or laser diodes.

14. The light-emitting device according to claim 12, where the light-emitting diode or laser diode emits UV-A or blue light.

15. Use of the phosphor ceramic material according to claims 1-8 in high-power applications.

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