Phosphors for high-power applications

Abstract

The present invention provides an improved luminance composition for high-power lighting applications. (A 1-x-y-z Ce x Tb y Eu z )3(Al 1-w Ga w )5O 12 A phosphor ceramic comprising a garnet material having a composition of, where A includes at least one selected from the group consisting of Y, Gd, La, Lu, Sc, and Sm; 0 < x ≦ 0.03, 0.2 < y ≦ 0.9, and 0 < z ≦ 0.05, where x + y + z ≦ 1 and 0 ≦ w < 1, is provided. Also, a. (A 1-x-y-z Ce x Tb y Eu z )3(Al 1-w Ga w )5O 12 The step of preparing a garnet material having a composition of, where A includes at least one selected from the group consisting of Y, Gd, La, Lu, Sc, and Sm; 0

Description

Field of Invention

[0001] This invention provides an improved luminescence composition for high-power lighting applications. Background of the Invention

[0002] Light intensity is 1 W / mm 2 For high-power lighting applications far exceeding this level, finding suitable color conversion materials is difficult.

[0003] Not all materials are suitable for production in the required form for high-power lighting devices. Typical white LEDs use green and red phosphors in a resin matrix, but 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 for such applications.

[0004] Some phosphor materials simply cannot process high light fluxes fast enough. Furthermore, due to the heat generated by high light intensity, many materials simply decompose and / or suffer from severe thermal quenching. The very limited amount of suitable phosphors available for these devices not only limits performance but also hinders the market penetration of solid-state lighting applications for high-power uses.

[0005] One class of materials suitable for high-power applications is Ce-doped garnet (e.g., "YAG:Ce" or "LuAG:Ce") phosphors in ceramic form. These phosphors exhibit broadband yellow / green emission, which can be used to generate cool white light. Ceramic materials have better thermal stability and thermal conductivity than resins. However, while yellow / green emission is feasible, finding a suitable red emitter has proven to be far more difficult. In fact, red ceramic materials are currently unavailable, and the most commonly used solution is to use the small amount of red light emitted by YAG:Ce. This is a very energy-inefficient method because unwanted emission must be removed.

[0006] Other methods for providing red light include, Eu 2+ Doped nitride phosphors are one example. However, at high light intensities, the quantum yield becomes very low due to photothermal quenching. This material also degrades rapidly due to the heat generated. Furthermore, Eu 2+ Doped nitride phosphors cannot be combined with YAG:Ce in ceramics. To overcome these problems, glass-encapsulated phosphor methods, in which powdered phosphors are suspended in a glass matrix, are being explored. Glass is more thermally stable than resin, but has lower thermal conductivity than ceramic. Furthermore, this method results in a lower phosphor packing density, leading to weaker luminescence.

[0007] US2019 / 0367809 discloses fluorescent powder materials and light-emitting devices.

[0008] Therefore, there remains a need for red-emitting phosphor materials for high-power applications. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 shows the emission spectra of the YAG:Ce, Tb, and Eu phosphors considered in Example 1. The excitation was at 450 nm. [Figure 2] Figure 2 shows the emission spectra of the LuAG:Ce, Tb, and Eu phosphors considered in Example 2. The excitation was at 450 nm. [Figure 3] Figure 3 shows the emission spectra of the YAGG:Ce, Tb, and Eu phosphors discussed in Example 3. The excitation was at 450 nm. [Figure 4] Figure 4 shows the emission spectra of the LuAGG:Ce, Tb, and Eu phosphors discussed in Example 4. The excitation was at 450 nm. [Figure 5] Figure 5 shows the emission spectra of the YAGG:Ce, Tb, Eu, and LuAGG:Ce phosphor mixtures discussed in Example 5. The excitation was at 450 nm. [Figure 6]Figure 6 shows the simulated emission spectra of a combination of LuAG:Ce, YAG:Eu, and a 450 nm pump LED, which had a CCT of 6000 K and a CRI of 87, as discussed in Example 7. [Figure 7] Figure 7 shows the simulated emission spectra of a combination of LuAG:Ce, YAG:Eu, and a 450 nm pump LED, which had a CCT of 3000 K and a CRI of 79, as discussed in Example 7. [Figure 8] Figure 8 shows the simulated emission spectra of a combination of YAG:Ce, YAG:Eu, and a 450 nm pump LED, which had a CCT of 3000 K and a CRI of 68, as discussed in Example 7. [Figure 9] Figure 9 shows the emission spectrum of Example 8, which had a CCT of 3112 K and a CRI of 66. [Figure 10] Figure 10 shows the emission spectrum of Example 9, which had a CCT of 5575 K and a CRI of 80. SUMMARY OF THE INVENTION

[0010] (A 1-x-y-z Ce x Tb y Eu z )3(Al 1-w Ga w )5O 12 A phosphor ceramic comprising a garnet material having a composition of, wherein A includes at least one selected from the group consisting of Y, Gd, La, Lu, Sc, and Sm; 0 < x ≦ 0.03, 0.2 < y ≦ 0.9, and 0 < z ≦ 0.05, where x + y + z ≦ 1 and 0 ≦ w < 1, is provided.

[0011] The phosphor ceramic has been found to be particularly suitable for high-power applications where high-quality (color rendering index over 70) white light is desired, by virtue of a combination of yellow / green, and red phosphors. Further, since the dopant ions are within a single material, the phosphors are more uniformly dispersed. The ceramic form is a good thermal conductor, preventing thermal quenching and degradation of the phosphors. A combination of effective light conversion and reduction of thermal quenching results in a more energy-efficient phosphor ceramic.

[0012] Also, a. Preparing 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 where A includes at least one selected from the group consisting of Y, Gd, La, Lu, Sc, and Sm; 0 < x ≦ 0.03, 0.2 < y ≦ 0.9, and 0 < z ≦ 0.05, with x + y + z ≦ 1; and 0 ≦ w < 1; b. Shaping it; and c. Sintering the formed shape A method for producing such a phosphor ceramic is provided, which includes the steps of a method for producing a phosphor ceramic.

[0013] By the method, high-quality phosphor ceramics can be easily produced. Detailed description

[0014] The term "phosphor" according to the present invention particularly refers to or encompasses a material that emits light, particularly within a wavelength range of 400 - 2500 nm (visible and infrared spectra), upon suitable excitation, particularly in the range of blue, violet, UV-A or UV-B (i.e., particularly 280 - 490 nm).

[0015] The term "phosphor ceramic" according to the present invention particularly refers to a ceramic consisting essentially of a luminescent material.

[0016] As used herein, the term "ceramic" according to the present invention refers to and / or includes a compact crystalline or polycrystalline material that contains a controlled amount of pores or is non-porous.

[0017] As used herein, the term "polycrystalline material" according to the present invention refers to and / or includes a material having a bulk density of more than 90% of the main component, consisting of more than 80% of individual crystal domains, each crystal domain having a diameter of 0.01 - 150 μm and different crystal orientations. The individual crystal domains may be bonded to each other or diluted via an amorphous or vitreous material or by a further crystal phase.

[0018] (A 1-x-y-z Ce x Tb y Eu z )3(Al 1-w Ga w )5O 12 A phosphor ceramic comprising a garnet material having a composition of, where 0 < x ≤ 0.03, 0.2 < y ≤ 0.9, and 0 < z ≤ 0.05, and x + y + z ≤ 1; 0 ≤ w < 1. A phosphor ceramic is provided, where A includes at least one selected from the group consisting of Y, Gd, La, Lu, Sc, and Sm. Thus, the garnet material has a composition of A3Al5O 12 garnet, where A is partially substituted with Ce, Tb, and Eu; and Al may be partially substituted with Ga.

[0019] Preferably, A is Y and / or Lu.

[0020] The Ce doping amount x is greater than 0 and less than or equal to 0.03. Since low Ce doping may result in insufficient Ce emission to absorb the desired proportion of excitation light, x is preferably 0.0005 or greater. High Ce doping can cause intermetallic charge transfer quenching between Ce and Eu, potentially reducing the quantum yield. High Ce doping can also cause reverse transfer from Tb to Ce. Therefore, x is preferably 0.003 or less. Preferably, 0.0005 ≤ x ≤ 0.003.

[0021] The Tb doping amount y is greater than 0.2 and less than or equal to 0.9. In addition to showing good luminescence for the desired color properties, Tb increases energy transfer from Ce to Eu. Therefore, y is preferably 0.3 or greater. Too much Tb can cause reverse transfer from Tb to Ce, potentially reducing the quantum yield due to concentration quenching. Therefore, y is preferably 0.85 or less. Preferably, 0.3 ≤ y ≤ 0.85.

[0022] The amount of Eu doping z is greater than 0 and less than or equal to 0.05. Since Eu emits red light, it is important for generating warm white light. Therefore, z is preferably 0.001 or greater. If the Eu doping is too high, intermetallic charge transfer quenching may occur between Ce and Eu, potentially reducing the quantum yield. Therefore, z is preferably 0.01 or less. Preferably, 0.001 ≤ z ≤ 0.01.

[0023] The total amount of doping must not exceed 1. It has been found that using these dopants in this ratio enables good conversion rates and good color characteristics in high-power applications.

[0024] The amount of Ga doping w is between 0 and 1. It has been found that including Ga can increase Eu emission and decrease Ce emission by reducing the reverse migration from Tb to Ce, which may improve color properties. Preferably, w is 0.2 ≤ w ≤ 0.6.

[0025] In one embodiment, the phosphor ceramic includes 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; 0 ≤ b < 1. Thus, the second garnet material is a (Y,Lu)3Al5O 12 garnet in which cerium is partially doped at the positions of Y and Lu, and Al may be partially substituted with Ga. The second garnet material contains only Ce as its luminescent ion, whereby the cerium emission intensity of the final phosphor ceramic can be adjusted. Since the first garnet material and the second garnet material have similar properties, they can be easily combined into a single ceramic. 12 The Ce doping amount a of the second garnet material is greater than 0 and not more than 0.02. Preferably, 0.0005 ≤ a ≤ 0.01. The Ga doping amount b is 0 or more and less than 1. Preferably, 0 ≤ b ≤ 0.6.

[0026]

[0027] The phosphor ceramic is preferably a translucent ceramic, and the in-line transmittance percentage measured using a double-beam spectrophotometer in the visible range (e.g., 420 - 700 nm) for a 0.2 mm ceramic sample is less than about 50%. Preferably, for a 0.2 mm ceramic sample, the in-line transmittance is about 0% - 20%. The translucency is obtained from scattering within the ceramic.

[0028] The phosphor ceramic further has a quantum yield of at least 60% when irradiated with light of 450 nm at 1 W / mm 2 and measured for a 0.2 mm thick ceramic sample, preferably higher than 70%, more preferably higher than 80%.

[0029] The phosphor ceramic may further contain any optical ceramic additives known in the art. Preferably, the additives are selected from the group consisting of scattering aids, thermal conductivity enhancers, or fluxes. More preferably, the additives are selected from the group consisting of alumina, silica, and magnesia. These additives have very high thermal conductivity and may improve the overall thermal conductivity of the ceramic. High thermal conductivity provides a ceramic that operates at a lower temperature under the operating conditions of the device, thereby resulting in better conversion efficiency. Furthermore, these may be added as fluxes during ceramic sintering. Preferably, the phosphor ceramic contains about 0.5% by weight or less of silica. At this amount, silica helps achieve higher densification in conventional garnet ceramics. Alumina also improves scattering and may therefore function as a scattering aid.

[0030] The phosphorescent ceramic has a volume density greater than 90 percent of the theoretical maximum density, as measured at room temperature using an electron densimeter (MD-300s) attached to an Alfa Mirage balance, preferably by using Archimedes' principle and water as a buoyant fluid. High density is desirable for thermal conductivity and the strength of the ceramic.

[0031] Preferably, the phosphor ceramic has a thickness of ≥0.1 mm to ≤2.0 mm. The thickness is defined as the shortest distance through the phosphor ceramic. These dimensions are suitable for use in light-emitting devices because they are generally the thickness required to achieve a desired rate of wavelength conversion. The phosphor ceramic exhibits good optical properties within these dimensions. In one embodiment, the phosphor ceramic is in the form of a plate with a diameter-to-thickness ratio greater than 5:1.

[0032] Preferably, the phosphorescent ceramic is a polycrystalline material consisting of more than 80 weight percent single-crystal domains, each domain having a diameter of less than approximately 150 μm and greater than approximately 10 nm.

[0033] Preparation method a.(A 1-x-y-z Cex Tb y Eu z )3(Al 1-w Ga w )5O 12 A step of preparing a garnet material having a composition of: A includes at least one selected from the group consisting of Y, Gd, La, Lu, Sc, and Sm; 0 < x ≤ 0.03, 0.2 < y ≤ 0.9, and 0 < z ≤ 0.05, where x + y + z ≤ 1; and 0 ≤ w < 1. b. A step of shaping the garnet material; and c. A step of sintering the formed shape A method for producing a phosphor ceramic is provided, which includes the above steps.

[0034] The phosphor ceramic of the present invention can be prepared by this method.

[0035] Step a. includes preparing 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 where A includes at least one selected from the group consisting of Y, Gd, La, Lu, Sc, and Sm; 0 < x ≤ 0.03, 0.2 < y ≤ 0.9, and 0 < z ≤ 0.05, where x + y + z ≤ 1; and 0 ≤ w < 1.

[0036] In one embodiment, step a. includes preparing a further 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.

[0037] In one embodiment, the garnet material is in the form of particles having a diameter of less than about 10 micrometers and greater than about 100 nm; and / or further, the garnet material is in the form of particles having a diameter of less than about 10 micrometers and greater than about 100 nm. Such particles are readily available and can be obtained with desired particle size and opacity.

[0038] In one embodiment, the garnet material is in the form of particles having a diameter of less than about 100 nm and greater than about 2 nm; and / or further, the garnet material is in the form of particles having a diameter of less than about 100 nm and greater than about 2 nm. The use of nanoparticles facilitates the mixing of the garnet material, lowers the sintering temperature, and increases the density.

[0039] Step b. includes shaping the garnet material. Step b. may include any known method for shaping the garnet material. For example, step b. includes axial and / or cold isostatic pressing, tape casting, slot die process, and / or thermoplastic process (e.g., injection molding, hot casting (low-pressure or medium-pressure injection molding), and / or extrusion). Preferably, step b. is carried out such that the compression process is performed at a pressure of >20 to <200 MPa.

[0040] Step c includes sintering the formed shape. This step allows a ceramic to be formed from the garnet material. Preferably, the sintering includes heating at a temperature of 1200-1800°C for 4-6 hours. If the garnet material and / or further garnet material is in the form of particles having a diameter of less than about 10 micrometers and greater than about 100 nm, the sintering preferably includes heating at a temperature of 1400-1800°C for 4-6 hours, or more preferably at about 1600°C for about 4 hours. If the garnet material and / or further garnet material is in the form of particles having a diameter of 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 10 -3 The procedure is carried out in a low-pressure atmosphere below mbar.

[0041] The method may further include recompressing the sintered ceramic by hot isostatic pressing and / or reworking the sintered ceramic by an ion beam preparation process in particular, or by mechanical machining or grinding processes using specified or unspecified cutting edges. In the case of hot isostatic pressing, this is preferably carried out so that the recompression is performed at a pressure of >120 to <180 MPa, preferably >140 to <160 MPa.

[0042] The method preferably further includes heating the sintered ceramic in an air atmosphere at 1000°C to 1300°C. Such post-annealing prevents blackening of the sintered body.

[0043] In this way, the phosphorescent ceramics suitable for most applications can be easily produced, and this method has proven to be useful.

[0044] Furthermore, a light-emitting device is provided. The light-emitting device includes the phosphor ceramic of the present invention.

[0045] Preferably, the light-emitting device has a power output of at least 1 W / mm². 2 The present invention further includes light-emitting diodes or laser diodes having a light emission intensity of . The phosphor ceramics of the present invention have been found to function well under such high-power conditions.

[0046] Preferably, the light-emitting diode or laser diode emits UV-A, violet, or blue light. These wavelengths are used in Ce in phosphor ceramics. 3+ This allows for suitable excitation. More preferably, the light-emitting diode or laser diode emits blue light, thereby allowing the blue light emission to be combined with the converted light emission, and good color rendering can be obtained in an efficient manner.

[0047] The phosphorescent ceramics according to the present invention can be used in a variety of specific topological structures or applications, including but not limited to the following:

[0048] 1. "Directly deposited phosphor ceramics": In some cases, the phosphorescent ceramic is applied directly onto the LED die as a thin sheet, using an intermediate binding material such as silicone, sol-gel, or glass.

[0049] 2. "Remote Phosphor" System: A "remote phosphor" system refers to a device in which phosphors are arranged away from a light source, particularly one that emits light in a narrow wavelength range, and are typically embedded in or bonded to a polymer, glass, or ceramic matrix. Therefore, remote phosphor systems are fundamentally different from systems in which phosphors are applied on or directly to a light source, such as in LED light sources where the phosphors are applied directly to the light-emitting die. They are generally distinguished into two basic structures from which many variations can be derived: a) "Remote phosphor in transmission applications": The phosphor matrix is ​​placed on a reflective chamber in which the LED is installed. Light can only escape through the phosphor matrix (transmission). b) "Remote phosphor in reflective mode applications": The phosphor matrix is ​​applied on a reflective carrier or coated with a reflective material on the back surface, and the LED light source is placed in or slightly to the side of the emission direction and irradiates the phosphor matrix. The converted light is re-emitted in the direction of the light source or the irradiation direction, and the light that has passed through the phosphor matrix is ​​directed again through the phosphor matrix in the emission direction by the back surface reflective layer. Therefore, light can only escape in the reflection direction. According to a preferred embodiment of the present invention, the ceramic phosphor may be optically coupled to an LED chip within the light-emitting system of the present invention. Such an LED chip may be based on a III-V nitride material system. For example, the LED chip may include a GalnN-based active region between an n-type GaN layer and a p-type GaN layer deposited on a suitable substrate (e.g., sapphire, silicon carbide, silicon, Ga2O3, or GaN itself) by a known method, such as metal-organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). Optical coupling from the LED active region to the ceramic phosphor may be performed via the substrate (in the case of a transparent substrate and flip-chip mounting configuration) or an epitaxial layer (in the case of substrate-down mounting, or when the substrate is removed, as in the case of a thin-film flip-chip LED architecture). The ceramic phosphor may also be physically attached to the LED chip, typically by a transparent adhesive, such as a silicone adhesive.

[0050] Alternatively, the ceramic phosphor may be mounted separately from the LED chip. Optical materials are provided to assist in the direction and / or mixing of the primary light from the LED chip and the light emitted by the ceramic phosphor. For example, silicone may be loaded with a reflective material (e.g., titania) and applied to surround the LED chip and the sides of the ceramic phosphor so that substantially all of the light passes through the top surface of the ceramic phosphor. This has the advantage of not only increasing brightness but also homogenizing color uniformity.

[0051] The LED chip may be mounted in a package, such as a ceramic package or a leadframe-based package, to provide mechanical stability and / or handling capabilities, as well as means of heat dissipation. Furthermore, the package may provide a stage for applying a lens surrounding the LED chip containing a ceramic phosphor. Such a lens may be fabricated from transparent silicone and molded in the form of a dome to assist in light extraction from the ceramic phosphor. Current is supplied to the LED chip via electrodes in the package that are electrically connected to ohmic contact material 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 active region of the LED. Depending on the detailed design of the LED active region, the primary emission wavelength range may be tuned. For example, in the case of GalnN, this range of protection may extend from UV-A to the entire visible spectrum. In particular, the primary emission wavelength may be selected to interact with the ceramic phosphor in a desired manner to provide a specific chromaticity of emission having, for example, specific color rendering properties.

[0052] One or more packaged LEDs, including LED chips and ceramic phosphors, as described above, may be used as part of a lighting system. Such a lighting system may be a lighting module, a lamp, or a luminaire. A lighting module may include multiple packaged LEDs and may include additional means for light adjustment (optics) and thermal management (passive or active heat sink means). Optionally, the module may further include electric drive means for supplying target current and voltage levels to the LEDs from a mains power supply or battery power supply. A lamp is typically formed in a standard housing configuration and typically includes, in addition to the LEDs, electric drive means for coupling to a mains power supply via a standard socket interface. Similarly, a luminaire has a housing and typically includes, in addition to the LEDs, electric drive means for coupling to a mains power supply. Furthermore, the lighting system may include sensing and / or communication electronics.

[0053] Furthermore, the use of the phosphor ceramic of the present invention in high-power applications is provided. The phosphor ceramic of the present invention is an improved Eu 3+ Due to their luminescence and thermal conductivity, they have been found to function well under such high-power applications.

[0054] The present invention may be further defined by the following clauses:

[0055] 1. (A 1-x-y-z Ce x Tb y EU z )3(Al 1-w Ga w )5O 12 A phosphor ceramic comprising a garnet material having the following composition, wherein A comprises at least one selected from the group consisting of Y, Gd, La, Lu, Sc, and Sm; 0 <x≦0.03、0.2<y≦0.9、および0<z≦0.05であり、x+y+z≦1であり、 A phosphorescent ceramic where 0 ≤ w < 1.

[0056] The phosphor ceramic according to any one of the preceding clauses, wherein 2.0.0005 ≦ x ≦ 0.003, 0.3 ≦ y ≦ 0.85, and / or 0.001 ≦ z ≦ 0.01.

[0057] 3. The phosphor ceramic according to any one of the preceding clauses, wherein A contains Y and / or Lu.

[0058] 4. The phosphor ceramic according to any one of the preceding clauses, 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.

[0059] 5. The phosphor ceramic according to any one of the preceding clauses, wherein 0.2 ≦ w ≦ 0.6 and / or 0 ≦ b ≦ 0.6.

[0060] 6. - A translucent ceramic with an in-line transmittance %T for a thickness of - 0.2 mm less than about 50%, preferably about 0 to about 20%; - A quantum yield measured by irradiating a ceramic sample with a thickness of 0.2 mm with light of 450 nm at 1 W / mm 2 and being at least 60%, preferably higher than 70%, more preferably higher than 80%; - A bulk density greater than 90 percent of the theoretical maximum density; and / or - Further comprising one or more additives selected from a scattering aid, a thermal conductivity improver, and a flux, preferably the additive is selected from alumina, silica, or magnesia, The phosphor ceramic according to any one of the preceding clauses.

[0061] 7. The phosphor ceramic according to clause 6, having a thickness of ≧ 0.1 mm to ≦ 2.0 mm.

[0062] A polycrystalline material composed of more than 8.80 weight percent of single crystal domains, wherein the diameter of each domain is less than about 150 μm and greater than about 10 nm, the phosphor ceramic according to any of the preceding clauses.

[0063] 9. a. A step of preparing 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 where A includes at least one selected from the group consisting of Y, Gd, La, Lu, Sc, and Sm; 0 < x ≦ 0.03, 0.2 < y ≦ 0.9, and 0 < z ≦ 0.05, and x + y + z ≦ 1; 0 ≦ w < 1; b. A step of shaping it; and c. A step of sintering the formed shape A method for producing a phosphor ceramic, comprising.

[0064] 10. The method according to clause 7, wherein step a. includes preparing a further 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; 0 ≦ b < 1, preferably 0 ≦ b < 0.6.

[0065] 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 micrometers and greater than about 100 nm; and / or The further garnet material is in the form of particles having a diameter less than about 10 micrometers and greater than about 100 nm.

[0066] 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 method according to clause 9 or 10, wherein the further garnet material is in the form of particles having a diameter of less than approximately 100 nm and greater than approximately 2 nm.

[0067] 13. The method according to any one of the clauses 9 to 12, wherein step b. includes axial and / or cold isostatic pressing, tape casting, slot die process and / or thermoplastic process (e.g., injection molding, hot casting (low-pressure or medium-pressure injection molding) and / or extrusion), preferably step b. is carried out such that the compression process is performed at a pressure of >20 to <200 MPa.

[0068] 14.c. is heated at a temperature of 1200~1800℃ for 4~6 hours, preferably 10 -3 The method according to any one of the provisions of 9 to 13, which includes heating in a low-pressure atmosphere of mbar or less.

[0069] 15. The method according to Clause 14, wherein the garnet material and / or further garnet material is in the form of particles having a diameter of less than about 10 micrometers and greater than about 100 nm, and the sintering comprises heating at a temperature of 1400 to 1800°C for 4 to 6 hours, preferably at about 1600°C for about 4 hours.

[0070] 16. The method according to Clause 14, wherein the garnet material and / or further garnet material is in the form of particles having a diameter less than about 100 nm and greater than about 2 nm, and the sintering comprises heating at a temperature of 1200 to 1600°C for 4 to 6 hours, preferably at about 1500°C for about 4 hours.

[0071] 17. The method according to any one of the clauses 9 to 16, further comprising heating the sintered ceramic in an air atmosphere at 1000°C to 1300°C.

[0072] 18. Preferably at least 1 W / mm 2 A light-emitting device comprising a phosphor ceramic according to Clauses 1 to 8, further comprising a light-emitting diode or laser diode having a light-emitting intensity.

[0073] 19. A light-emitting device as described in Clause 18, wherein the light-emitting diode or laser diode emits light in UV-A or blue light.

[0074] 20. Use of phosphorescent ceramic materials as described in Clauses 1 to 8 for high-power applications.

[0075] [example] Comparative example A: Ce 3+ , Tb 3+ Co-doped YAG A YAG:0.1%Ce, 76.8%Tb phosphor powder was prepared by weighing 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. All chemicals were dissolved in 5 ml of deionized water. The solution was heated and boiled until a foamy substance was achieved. The foam was crushed and the mixture was transferred to an alumina crucible. The mixture was calcined in air at 1000°C for 2 hours. The sample was crushed again and calcined in air at 1500°C for 4 hours. A yellow powder sample was obtained.

[0076] Ce and Tb-doped YAG showed broad Ce emission when excited at 450 nm. 3+ →Ce 3+ It did not show a Tb peak due to reverse energy transfer.

[0077] Example 1: Ce 3+ , Tb 3+ ,EU 3+ Co-doped YAG 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 were weighed to prepare YAG: 0.1% Ce, 76.8% Tb, 0.2% Eu phosphor powder. All the chemicals were dissolved in 5 ml of deionized water. The solution was heated and boiled until a foamy substance was achieved. The foam was crushed and transferred to an alumina crucible. Calcination was performed at 1000 °C for 2 hours in air. The sample was crushed again and calcined at 1500 °C for 4 hours in air. A yellow powder sample was achieved.

[0078] Ce, Tb, Eu co-doped YAG showed a broad Ce emission along with strong Eu line emission under 450 nm excitation (Figure 1).

[0079] Example 2: Ce 3+ , Tb 3+ ,EU 3+ Co-doping LuAG 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 were weighed to prepare LuAG: 0.1% Ce, 76.8% Tb, 0.2% Eu phosphor powder. All the chemicals were dissolved in 5 ml of deionized water. The solution was heated and boiled until a foamy substance was achieved. The foam was crushed and transferred to an alumina crucible. Calcination was performed at 1000 °C for 2 hours in air. The sample was crushed again and calcined at 1500 °C for 4 hours in air. A yellow powder sample was achieved.

[0080] Ce, Tb, Eu co-doped LuAG showed a broad Ce emission along with strong Eu line emission under 450 nm excitation (Figure 2).

[0081] Example 3: Ce 3+ , Tb 3+ ,EU 3+ Co-dope YAGG 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 were weighed to prepare YAGG:0.1%Ce, 76.8%Tb, 0.2%Eu phosphor powder containing 45% gallium at the aluminum site. All the chemical substances were dissolved in 5 ml of deionized water. The solution was heated and boiled until a foamy substance was achieved. The foam was crushed and transferred to an alumina crucible. Calcination was carried out at 1000 °C for 2 hours in air. The sample was crushed again and calcined at 1500 °C for 4 hours in air. A yellow powder sample was achieved.

[0082] Ce, Tb, Eu co-doped YAGG showed strong Eu line emission under 450 nm excitation (Figure 3). Since most of the energy was transferred to Eu via the Tb intermediate, the broad Ce emission was very weak.

[0083] Example 4: Ce 3+ , Tb 3+ ,EU 3+ Co-dope LuAGG 0.30 g of lutetium 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 were weighed to prepare LuAGG:0.1%Ce, 76.8%Tb, 0.2%Eu phosphor powder containing 45% gallium at the aluminum site. All the chemical substances were dissolved in 5 ml of deionized water. The solution was heated and boiled until a foamy substance was achieved. The foam was crushed and transferred to an alumina crucible. Calcination was carried out at 1000 °C for 2 hours in air. The sample was crushed again and calcined at 1500 °C for 4 hours in air. A yellow powder sample was achieved.

[0084] Ce, Tb, and Eu-doped LuAGG exhibited strong Eu-line emission under 450 nm excitation (Figure 4). Broad Ce emission disappeared because all energy was transferred to Eu via the Tb intermediate.

[0085] Example 5: Ce 3+ , Tb 3+ ,EU 3+ Co-dope YAGG-Ce 3+ Doped LuAGG mixed phosphor By following the procedure described above, YAGG:0.1%Ce, 60%Tb, 0.2%Eu phosphor powder containing 20% ​​gallium at the aluminum site was prepared. Similarly, LuAGG:0.5%Ce phosphor powder containing 20% ​​gallium at the aluminum site was prepared. Ce, Tb, and Eu co-doped YAGG exhibited broad Ce emission and strong Eu line emission under 450 nm excitation. Ce-doped LuAGG exhibited broad blue-green emission under 450 nm excitation. The Ce, Tb, and Eu co-doped YAGG and Ce-doped LuAGG phosphors were mixed in a 5:1 ratio. The emission of the mixed phosphors covered the broad spectral range necessary to achieve high CRI white LED emission (Figure 5).

[0086] Example 6: Mixed phosphor ceramic The Ce, Tb, and Eu co-doped YAGG and Ce-doped LuAGG phosphor mixtures prepared in Example 5 were mixed with TEOS to achieve a final silica content of approximately 1%. The powder was uniaxially pressed under a 10-ton load to form thin pellets (approximately 0.5 mm thick). The pellets were annealed in a nitrogen atmosphere at 1400°C for 4 hours to obtain a mixed phosphor ceramic. The emission spectrum of the pellets prepared in this example shows a spectral profile similar to that of the phosphor powder described in Example 5 (Figure 5).

[0087] Example 7: Simulated Spectrum The emission spectrum obtained from Example 4 was combined with the LuAGG:Ce spectrum from Example 5, the YAG:Ce emission spectrum obtained by measuring a commercially available YAG:Ce (3%) sample, and the emission spectrum of a 450nm LED to obtain a simulated spectrum.

[0088] In the first simulated experiment, the spectrum from Example 4, the emission spectrum of LuAG:Ce, and the emission spectrum of a 450nm LED were combined to achieve a CCT of 6000K. The combined simulated spectrum showed a CRI of 87 (Figure 6).

[0089] In the second simulation experiment, the spectrum from Example 4, the emission spectrum of LuAG:Ce, and the emission spectrum of a 450nm LED were combined to achieve a CCT of 3000K. The combined simulated spectrum showed a CRI of 79 (Figure 7).

[0090] In the third simulation experiment, the spectra from Example 4, YAG:Ce, and a 450nm LED were combined to achieve a CCT of 3000K. The combined simulated spectra showed 68 CRIs (Figure 8).

[0091] Example 8: LED spectrum The material from Example 4 was mixed with LuAG:Ce and then mixed into silicone. Next, a droplet was placed on a 450 nm LED chip, and the thickness was adjusted until the spectrum lay on the blackbody line of the CIE 1931 xy chromaticity diagram. The spectrum showed a correlated color temperature of 3112 K and a CRI of 66 (Figure 9).

[0092] Example 9: LED spectrum The mixed phosphor material from Example 5 was mixed in silicone. Next, a droplet was placed on a 450 nm LED chip, and the thickness was adjusted until the spectrum lay on the blackbody line of the CIE 1931 xy chromaticity diagram. The spectrum showed a correlated color temperature of 5575 K and a CRI of 80 (Figure 10).

Claims

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

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

01.

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

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

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

6.

6. - A translucent ceramic having an in-line transmittance %T of less than about 50% for a thickness of 0.2 mm, preferably about 0 to about 20%; - A 0.2 mm thick ceramic sample is exposed to 450 nm light at 1 W / mm². ２ The quantum yield measured by irradiation is at least 60%, preferably higher than 70%, and more preferably higher than 80%; - Volume density is greater than 90 percent of the theoretical maximum density; and / or - Further comprising one or more additives selected from scattering aids, thermal conductivity enhancers, and fluxes, preferably the additive being selected from alumina, silica, or magnesia. A phosphor ceramic according to any of the preceding claims.

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

8. A phosphor ceramic according to any of the preceding claims, which is a polycrystalline material comprising more than 80 weight percent of single-crystal domains, wherein the diameter of each domain is less than about 150 μm and greater than about 10 nm.

9. a. (A １－ｘ－ｙ－ｚ Ce ｘ Tb ｙ Eu ｚ ) ３ (Al １－ｗ Ga ｗ ) ５ O １２ A step of preparing a garnet material having the following composition, wherein A comprises at least one selected from the group consisting of Y, Gd, La, Lu, Sc, and Sm; 0 < x ≤ 0.03, 0.2 < y ≤ 0.9, and 0 < z ≤ 0.05, x + y + z ≤ 1; 0 ≤ w < 1; b. The process of forming it into shape; and c. A process of sintering the formed shape. A method for producing phosphorescent ceramics, including the above.

10. Process a. is ((Y, Lu) １－ａ (Ce) ａ ) ３ (Al （１－ｂ） Ga ｂ ) ５ O １２ The method according to claim 7, comprising preparing a further garnet material having the composition of 0 < a ≤ 0.02, preferably 0.0005 ≤ a ≤ 0.01; and 0 ≤ b < 1, preferably 0 ≤ b < 0.

6.

11. The garnet material is in the form of particles having a diameter of less than about 10 micrometers and greater than about 100 nm; and / or The method according to claim 9 or 10, wherein the further garnet material is in the form of particles having a diameter of less than about 10 micrometers and greater than about 100 nm.

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

13. Preferably at least 1 W / mm ２ A light-emitting device comprising a phosphor ceramic according to claims 1 to 8, further comprising a light-emitting diode or laser diode having a light-emitting intensity.

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

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

Images