Fluorescent ceramic and method for preparing the same, light emitting device

Abstract

This application provides a fluorescent ceramic, its preparation method, and a light-emitting device. The fluorescent ceramic includes a fluorescent ceramic substrate having an incident surface, an emitting surface, and a side surface. The incident surface and the emitting surface are arranged opposite to each other, and the side surface is located between the incident surface and the emitting surface. The emitting surface and at least a portion of the side surface have etched texture structures. Light is significantly scattered by the etched texture structures on the emitting surface and the side surface, and ultimately recombines to form more homogeneous white light emission, thereby significantly improving the "yellow edge effect."

Description

Technical Field

[0001] This invention relates to the field of fluorescent ceramics technology, and in particular to a fluorescent ceramic, its preparation method, and a light-emitting device. Background Technology

[0002] Fluorescent ceramics are functional materials capable of light-to-light conversion when excited by blue LED light sources. Current high-performance white LEDs typically employ a design that uses a blue LED chip to excite a yellow-green oxide transparent fluorescent ceramic. However, fluorescent ceramics have high transmittance and a refractive index greater than that of air, and their internal surface exhibits internal reflection. Under the influence of the optical waveguide, this results in a larger amount of light emitted from the sides, producing a "yellow edge effect," leading to poor uniformity of light emission in the light-emitting device. Summary of the Invention

[0003] Therefore, it is necessary to provide a method for preparing fluorescent ceramics to address the problems mentioned in the background art, so as to improve the "yellow edge effect" in fluorescent ceramics and thereby improve the uniformity of light emission of light-emitting devices.

[0004] According to some embodiments of this application, a fluorescent ceramic is provided, which includes a fluorescent ceramic substrate having a light-incident surface, a light-emitting surface, and a side surface. The light-incident surface and the light-emitting surface are disposed opposite to each other, and the side surface is located between the light-incident surface and the light-emitting surface. The light-emitting surface and at least a portion of the side surface have corrosion texture structures formed by etching.

[0005] In some embodiments of this application, the surface roughness of the etched texture structure is 200nm~500nm.

[0006] In some embodiments of this application, the surface roughness of the light-incident surface is ≤20nm.

[0007] In some embodiments of this application, a functional film is also included, which is stacked on the side of the light-incident surface away from the light-outceasing surface, and the functional film is selected from blue anti-reflection film or anti-reflection film.

[0008] In some embodiments of this application, the material of the fluorescent ceramic substrate includes cerium-doped yttrium aluminum garnet.

[0009] Furthermore, this application also provides a method for preparing fluorescent ceramics, comprising the following steps: etching the light-emitting surface and at least part of the side surfaces of a fluorescent ceramic sheet using an etching solution including phosphoric acid, and forming the fluorescent ceramic substrate based on the fluorescent ceramic sheet.

[0010] In some embodiments of this application, during the step of etching the light-emitting surface and at least part of the side surfaces of the fluorescent ceramic sheet, the temperature of the etching solution is controlled to be 100°C to 300°C; and / or,

[0011] In the step of etching the light-emitting surface and at least part of the side surfaces of the fluorescent ceramic sheet, the etching time is controlled to be 1 min to 60 min.

[0012] In some embodiments of this application, the light transmittance of the fluorescent ceramic sheet is >30% before the light-emitting surface and at least part of the side surfaces of the fluorescent ceramic sheet are etched.

[0013] In some embodiments of this application, a step of polishing the light-incident surface of the fluorescent ceramic sheet is also included, wherein the surface roughness of the light-incident surface is ≤20nm during the polishing process.

[0014] Furthermore, this application also provides a light-emitting device, which includes a light source and an encapsulation layer for encapsulating the light source. The encapsulation layer includes fluorescent ceramic as described in the above embodiments, and the light source is disposed on the side of the fluorescent ceramic substrate away from the light-emitting surface.

[0015] In the fluorescent ceramic of this application, the fluorescent ceramic substrate has an incident surface and an emitting surface disposed opposite to each other, as well as a side surface located between the incident surface and the emitting surface. The emitting surface and at least part of the side surface have an etching texture structure formed by etching the fluorescent ceramic substrate. When the light emitted by the light source enters the fluorescent ceramic substrate from the incident surface, it first undergoes fluorescence conversion inside the fluorescent ceramic substrate, and then undergoes a large amount of scattering under the action of the etching texture structure on the emitting surface and the side surface. Finally, it recombines to form a more homogeneous white light emission, thereby significantly improving the problem of the "yellow edge effect" on the side caused by the waveguide effect and improving the uniformity of light emission of the light-emitting device.

[0016] Furthermore, in traditional techniques to improve the "yellow edge effect," micro-hole arrays or photonic crystal lattices are typically engraved on the light-emitting surface of the fluorescent ceramic, or further optical design is performed on the overall lamp structure. However, these methods require expensive equipment and relatively complex fabrication processes. In contrast, the etched texture structure on the light-incident surface and side surfaces of the fluorescent ceramic substrate in this application can be obtained simply by etching, significantly reducing equipment requirements and simplifying the manufacturing process. Therefore, the production cost of this fluorescent ceramic is also significantly lower.

[0017] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the cross-sectional structure of a fluorescent ceramic.

[0020] Figure 2 This is a schematic diagram illustrating the steps of a method for preparing fluorescent ceramics.

[0021] Figure 3 This is a schematic diagram of the structure of a light-emitting device;

[0022] Figure 4 The images show the microscopic surface morphology of the fluorescent ceramic substrates prepared in Comparative Example 1 and Examples 1 to 5 under a scanning electron microscope.

[0023] Figure 5 The images show the microscopic surface morphology of the fluorescent ceramic substrates prepared in Examples 6 to 9 under a scanning electron microscope.

[0024] Figure 6 The image shows the light transmittance of the fluorescent ceramic substrates prepared in Comparative Example 1 and Example 8 under the same light source.

[0025] Figure 7 This is a schematic diagram of the angular emission distribution of the light-emitting devices in Example 10 and Comparative Example 1.

[0026] The reference numerals and their meanings in the attached figures are as follows:

[0027] 100, Fluorescent ceramic substrate; 101, Light-emitting surface; 102, Light-incident surface; 103, Side surface; 1001, Etched texture structure; 110, Functional film; 200, Light source. Detailed Implementation

[0028] To facilitate understanding of this document, a more comprehensive description will be provided below. Preferred embodiments are given herein. However, this document can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the content of this document more thorough and comprehensive.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this document belongs. The terminology used herein in the specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the document.

[0030] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or parts, these elements, components, areas, layers, and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or part from another element, component, area, layer, or part.

[0031] Spatial relation terms such as “below,” “under,” “below,” “below,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship of one element or feature to other elements or features. It should be understood that spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figures is flipped, then the element or feature described as “below,” “below,” or “below” other elements or features will be oriented “above” other elements or features. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. Devices may be oriented in other ways (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used will be interpreted accordingly.

[0032] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprise” and / or “comprising,” when used in this specification, identify the presence of features, integers, steps, operations, elements, and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0033] This application provides a fluorescent ceramic, which includes a fluorescent ceramic substrate having a light-incident surface, a light-emitting surface, and a side surface. The light-incident surface and the light-emitting surface are arranged opposite to each other, and the side surface is located between the light-incident surface and the light-emitting surface. The light-emitting surface and at least a portion of the side surface have corrosion texture structures formed by etching.

[0034] In the fluorescent ceramic of this application, the fluorescent ceramic substrate has an incident surface and an emitting surface disposed opposite to each other, as well as a side surface located between the incident surface and the emitting surface. The emitting surface and at least part of the side surface have an etching texture structure formed by etching the fluorescent ceramic substrate. When the light emitted by the light source enters the fluorescent ceramic substrate from the incident surface, it first undergoes fluorescence conversion inside the fluorescent ceramic substrate, and then undergoes a large amount of scattering under the action of the etching texture structure on the emitting surface and the side surface. Finally, it recombines to form a more homogeneous white light emission, thereby significantly improving the problem of the "yellow edge effect" on the side caused by the waveguide effect and improving the uniformity of light emission of the light-emitting device.

[0035] Furthermore, in traditional techniques to improve the "yellow edge effect," micro-hole arrays or photonic crystal lattices are typically engraved on the light-emitting surface of the fluorescent ceramic, or further optical design is performed on the overall lamp structure. However, these methods require expensive equipment and relatively complex fabrication processes. In contrast, the etched texture structure on the light-incident surface and side surfaces of the fluorescent ceramic substrate in this application can be obtained simply by etching, significantly reducing equipment requirements and simplifying the manufacturing process. Therefore, the production cost of this fluorescent ceramic is also significantly lower.

[0036] Figure 1 This is a schematic diagram of the cross-sectional structure of a fluorescent ceramic. (Refer to...) Figure 1 As shown, the fluorescent ceramic includes a fluorescent ceramic substrate 100, which has a light-incident surface 102, a light-emitting surface 101, and a side surface 103. The light-incident surface 102 and the light-emitting surface 101 are arranged opposite to each other, and the side surface 103 is located between the light-incident surface 102 and the light-emitting surface 101. The light-emitting surface 101 and at least a portion of the side surface 103 have corrosion texture structures 1001 formed by etching.

[0037] In this embodiment, the fluorescent ceramic substrate 100 may be planar or curved.

[0038] It can be understood that the corrosion texture structure 1001 refers to the uneven, undulating surface structure formed after corrosion. This corrosion texture structure 1001 has a diffuse reflection effect on light, and light shining on this corrosion texture structure 1001 in the same direction will be reflected in different directions.

[0039] In some examples of this embodiment, the surface roughness of the etched texture structure 1001 is 200nm to 500nm. For example, the surface roughness of the etched texture structure 1001 can be 200nm, 230nm, 250nm, 270nm, 300nm, 330nm, 350nm, 370nm, 400nm, 430nm, 450nm, 470nm, or 500nm, or the surface roughness of the etched texture structure 1001 can be between any two of the above roughnesses. Controlling the surface roughness of the etched texture structure 1001 within this range enables the etched texture structure to have a strong diffuse reflection effect on light.

[0040] In some examples of this embodiment, the erosion texture structure 1001 may include multiple protrusions.

[0041] In some examples of this embodiment, in the etched texture structure 1001, more than 90% of the protrusions have a maximum radial width of 10 μm to 100 μm. Here, "maximum radial width" refers to the distance between the two furthest points on the edge of the protrusion.

[0042] It is understood that the etched texture structure 1001 can be formed through etching. The etchant can be selected corresponding to the fluorescent ceramic substrate 100. For example, in some examples of this embodiment, the material of the fluorescent ceramic substrate 100 may include cerium-doped yttrium aluminum garnet (Ce:YAG). Cerium-doped yttrium aluminum garnet can produce yellow-green fluorescence when irradiated with blue light, so encapsulating a blue light source with it can ultimately obtain white emitted light. Accordingly, the etchant may contain phosphoric acid.

[0043] In this embodiment, the light-emitting surface 101 and at least a portion of the side surface 103 have an etched texture structure 1001. The side surface 103 with the etched texture structure 1001 works in conjunction with the light-emitting surface 101 to significantly improve the "yellow edge effect" problem on the side surface 103 with the etched texture structure 1001. (Refer to...) Figure 1 As shown, in some examples of this embodiment, the entire side surface 103 of the fluorescent ceramic substrate 100 is provided with an etched texture structure 1001. It can be understood that providing an etched texture structure 1001 on the entire side surface 103 can significantly improve the overall "yellow edge effect" of the fluorescent ceramic.

[0044] In some examples of this embodiment, the surface roughness of the light-incident surface 102 is ≤20nm. For example, the surface roughness of the light-incident surface 102 can be 20nm, 18nm, 16nm, 15nm, 13nm, 10nm, 9nm, 8nm, 7nm, 6nm, 5nm, 4nm, 3nm, 2nm, or 1nm, or the surface roughness of the light-incident surface 102 can be between any two of the above roughness ranges. Controlling the surface roughness of the light-incident surface 102 to be low can minimize the scattering of light when it enters the fluorescent ceramic, thereby increasing the amount of light received by the fluorescent ceramic.

[0045] Reference Figure 1 As shown, in some examples of this embodiment, the fluorescent ceramic may further include a functional film 110. The functional film 110 is stacked on the side of the light-incident surface 102 away from the light-emitting surface 101, and the functional film 110 may be selected from a blue anti-reflection film or an anti-reflection film. Providing a blue anti-reflection film or an anti-reflection film on the light-incident surface 102 of the fluorescent ceramic substrate 100 can further increase the amount of light incident on the fluorescent ceramic.

[0046] In some examples of this embodiment, the blue antireflective film can reduce the reflection of light in the wavelength range of 440nm to 460nm.

[0047] Furthermore, this application also provides a method for preparing fluorescent ceramics, which includes the following steps: etching the light-emitting surface and at least part of the side surfaces of a fluorescent ceramic sheet using an etching solution including phosphoric acid to form a fluorescent ceramic substrate 100.

[0048] Figure 2 This is a schematic diagram illustrating the steps of a method for preparing fluorescent ceramics. (Refer to...) Figure 2 As shown, the preparation method of this fluorescent ceramic includes steps S1 to S3, as detailed below.

[0049] Step S1: The light-emitting surface and at least part of the side surfaces of the fluorescent ceramic sheet are etched using an etching solution containing phosphoric acid.

[0050] In some examples of this embodiment, the material of the fluorescent ceramic sheet may include cerium-doped yttrium aluminum garnet. Phosphoric acid in the etching solution has a good etching effect on the surface of cerium-doped yttrium aluminum garnet, and can form an etching texture structure 1001 with diffuse reflection on its surface.

[0051] In some examples of this embodiment, a pre-cleaning step of the fluorescent ceramic sheet is included before etching the light-emitting surface and at least part of the side surfaces of the fluorescent ceramic sheet.

[0052] In some examples of this embodiment, the pre-cleaning step of the fluorescent ceramic sheet may include: ultrasonically cleaning the fluorescent ceramic sheet sequentially with a surfactant, deionized water, acetone, and anhydrous ethanol. Each ultrasonic cleaning session may last from 5 to 15 minutes.

[0053] In some examples of this embodiment, after pre-cleaning the fluorescent ceramic sheet, a step of drying the fluorescent ceramic sheet is also included.

[0054] In some examples of this embodiment, when etching the fluorescent ceramic sheet, the entire sheet can be immersed in the etching solution. It is understood that in other examples, the light-emitting surface and at least some of the side surfaces of the fluorescent ceramic sheet can also be selectively etched. However, immersing the entire fluorescent ceramic sheet in the etching solution reduces process complexity and improves production efficiency.

[0055] In some examples of this embodiment, the corrosive solution may be an aqueous solution of phosphoric acid.

[0056] In some examples of this embodiment, a boiling etchant can be used to etch the fluorescent ceramic sheet.

[0057] In some examples of this embodiment, during the step of etching the light-emitting surface and at least part of the side surfaces of the fluorescent ceramic sheet, the temperature of the etching solution can be controlled to be between 100°C and 300°C. For example, the temperature of the etching solution can be controlled to be 100°C, 120°C, 150°C, 180°C, 200°C, 220°C, 250°C, 280°C, or 300°C, or the temperature of the etching solution can be controlled within any two of the above temperatures.

[0058] Furthermore, in the step of etching the light-emitting surface and at least part of the side surface of the fluorescent ceramic sheet, the temperature of the etching solution can be controlled above 150°C to obtain an etching texture structure 1001 with a large surface roughness, thereby improving the effect of the etching texture structure 1001 on the "yellow edge effect".

[0059] In some examples of this embodiment, the etching time is controlled to be 1 min to 60 min during the step of etching the light-emitting surface and at least part of the side surface of the fluorescent ceramic sheet. For example, the etching time can be controlled to be 1 min, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min, or 60 min, or the etching time can be controlled to be between any two of the above durations.

[0060] Furthermore, in the step of etching the light-emitting surface and at least part of the side surfaces of the fluorescent ceramic sheet, the etching time can be controlled to be 10 min to 30 min, so as to improve the production rate while obtaining a better diffuse reflection effect.

[0061] In some examples of this embodiment, the transmittance of the fluorescent ceramic sheet is >30% before the light-emitting surface and at least part of the side surface of the fluorescent ceramic sheet are etched.

[0062] In some examples of this embodiment, after etching the light-emitting surface and at least part of the side surfaces of the fluorescent ceramic sheet, a post-cleaning step of the fluorescent ceramic sheet is also included.

[0063] In some examples of this embodiment, the post-cleaning step of the fluorescent ceramic sheet may include: ultrasonically cleaning the fluorescent ceramic sheet sequentially with deionized water, acetone, and anhydrous ethanol. Each ultrasonic cleaning session may last from 5 to 15 minutes.

[0064] In some examples of this embodiment, after post-cleaning the fluorescent ceramic sheet, a step of drying the fluorescent ceramic sheet is also included.

[0065] Step S2: Polish the light-incident surface of the fluorescent ceramic sheet.

[0066] The polishing process for the light-incident surface of the fluorescent ceramic sheet can be performed using known polishing methods, such as placing the fluorescent ceramic sheet in a polishing machine and adding polishing fluid for polishing. Polishing can significantly reduce the surface roughness of the light-incident surface of the fluorescent ceramic sheet and obtain a smooth light-incident surface 102.

[0067] In some examples of this embodiment, the light-incident surface of the fluorescent ceramic sheet can be polished using a fine polishing method.

[0068] In some examples of this embodiment, the surface roughness of the incident surface 102 is ≤20nm during the polishing process.

[0069] It is understandable that, by combining steps S1 to S2, the following can be formed: Figure 1 The fluorescent ceramic substrate 100 in the middle.

[0070] Step S3: Deposit a functional film 110 on the light-incident surface 102 of the fluorescent ceramic substrate 100.

[0071] In some examples of this embodiment, the functional film 110 is stacked on the side of the light-incident surface 102 away from the light-emitting surface 101. The functional film 110 can be selected from blue anti-reflection film or anti-reflection film. Depositing a blue anti-reflection film or anti-reflection film on the light-incident surface 102 of the fluorescent ceramic substrate 100 can further increase the amount of light incident on the fluorescent ceramic.

[0072] In some examples of this embodiment, the blue antireflective film can reduce the reflection of light in the wavelength range of 440nm to 460nm.

[0073] It is understandable that through steps S1 to S3, the following can be prepared: Figure 1 The fluorescent ceramic shown.

[0074] In this embodiment, the fluorescent ceramic sheet is first placed in an etching solution containing phosphoric acid. The etching solution etches depressions and multiple protrusions on the surface of the fluorescent ceramic sheet, thereby obtaining an etching texture structure 1001. The surface roughness of the fluorescent ceramic sheet after etching is significantly increased, resulting in a stronger diffuse reflection effect for light. Furthermore, the light-incident surface 102 of the fluorescent ceramic sheet is polished after etching to make it a flat surface, which further reduces the equipment requirements for the fluorescent ceramic sheet, simplifies the production process, and improves production efficiency. In addition, compared with other processes in traditional technologies to improve the "yellow edge effect," this method for preparing fluorescent ceramics is simple and easy to implement, reduces production costs, and is suitable for large-scale production.

[0075] This application also provides a light-emitting device. Figure 3 This is a schematic diagram of the structure of a light-emitting device according to this application. (Refer to...) Figure 3 As shown, the light-emitting device includes a light source 200 and an encapsulation layer for encapsulating the light source 200. The encapsulation layer includes fluorescent ceramic as described in the above embodiment. The light source 200 is disposed on the side of the light incident surface 102 of the fluorescent ceramic substrate 100 away from the light emitting surface 101.

[0076] In some examples of this embodiment, the light source 200 may be an LED lamp. Further, the LED lamp may be an LED lamp capable of emitting blue light.

[0077] To more clearly illustrate the implementation and advantages of this application, more specific embodiments and comparative examples are provided below. Through the description of these embodiments and comparative examples, the implementation and advantages of this application will become more apparent.

[0078] Example 1

[0079] Cerium-doped yttrium aluminum garnet (Ce:YAG) is provided as a fluorescent ceramic sheet, wherein the atomic percentage of Ce is 0.02%.

[0080] The fluorescent ceramic sheet was ultrasonically cleaned for 10 minutes each with dish soap, deionized water, acetone, and anhydrous ethanol, and then dried in an oven at 50°C.

[0081] The pre-cleaned fluorescent ceramic sheet was immersed in a phosphoric acid solution for etching, with the temperature of the phosphoric acid solution controlled at 100℃. After etching for 1 hour, the fluorescent ceramic sheet was removed and ultrasonically cleaned for 5 minutes each with deionized water, acetone, and anhydrous ethanol. Then it was dried in an oven at 50℃ to serve as a fluorescent ceramic substrate.

[0082] The light-incident surface of the fluorescent ceramic sheet is finely polished.

[0083] Example 2

[0084] Cerium-doped yttrium aluminum garnet (Ce:YAG) is provided as a fluorescent ceramic sheet, wherein the atomic percentage of Ce is 0.02%.

[0085] The fluorescent ceramic sheet was ultrasonically cleaned for 10 minutes each with dish soap, deionized water, acetone, and anhydrous ethanol, and then dried in an oven at 50°C.

[0086] The pre-cleaned fluorescent ceramic sheet was immersed in a phosphoric acid solution for etching, with the temperature of the phosphoric acid solution controlled at 150℃. After etching for 1 hour, the fluorescent ceramic sheet was removed and ultrasonically cleaned for 5 minutes each with deionized water, acetone, and anhydrous ethanol. Then it was dried in an oven at 50℃ to serve as a fluorescent ceramic substrate.

[0087] The light-incident surface of the fluorescent ceramic sheet is finely polished.

[0088] Example 3

[0089] Cerium-doped yttrium aluminum garnet (Ce:YAG) is provided as a fluorescent ceramic sheet, wherein the atomic percentage of Ce is 0.02%.

[0090] The fluorescent ceramic sheet was ultrasonically cleaned for 10 minutes each with dish soap, deionized water, acetone, and anhydrous ethanol, and then dried in an oven at 50°C.

[0091] The pre-cleaned fluorescent ceramic sheet was immersed in a phosphoric acid solution for etching, with the temperature of the phosphoric acid solution controlled at 200℃. After etching for 1 hour, the fluorescent ceramic sheet was removed and ultrasonically cleaned for 5 minutes each with deionized water, acetone, and anhydrous ethanol. Then it was dried in an oven at 50℃ to serve as a fluorescent ceramic substrate.

[0092] The light-incident surface of the fluorescent ceramic sheet is finely polished.

[0093] Example 4

[0094] Cerium-doped yttrium aluminum garnet (Ce:YAG) is provided as a fluorescent ceramic sheet, wherein the atomic percentage of Ce is 0.02%.

[0095] The fluorescent ceramic sheet was ultrasonically cleaned for 10 minutes each with dish soap, deionized water, acetone, and anhydrous ethanol, and then dried in an oven at 50°C.

[0096] The pre-cleaned fluorescent ceramic sheet was immersed in a phosphoric acid solution for etching, with the temperature of the phosphoric acid solution controlled at 250℃. After etching for 1 hour, the fluorescent ceramic sheet was removed and ultrasonically cleaned for 5 minutes each with deionized water, acetone, and anhydrous ethanol. Then it was dried in an oven at 50℃ to serve as a fluorescent ceramic substrate.

[0097] The light-incident surface of the fluorescent ceramic sheet is finely polished.

[0098] Example 5

[0099] Cerium-doped yttrium aluminum garnet (Ce:YAG) is provided as a fluorescent ceramic sheet, wherein the atomic percentage of Ce is 0.02%.

[0100] The fluorescent ceramic sheet was ultrasonically cleaned for 10 minutes each with dish soap, deionized water, acetone, and anhydrous ethanol, and then dried in an oven at 50°C.

[0101] The pre-cleaned fluorescent ceramic sheet was immersed in a phosphoric acid solution for etching, with the temperature of the phosphoric acid solution controlled at 300℃. After etching for 1 hour, the fluorescent ceramic sheet was removed and ultrasonically cleaned for 5 minutes each with deionized water, acetone, and anhydrous ethanol. Then it was dried in an oven at 50℃ to serve as a fluorescent ceramic substrate.

[0102] The light-incident surface of the fluorescent ceramic sheet is finely polished.

[0103] Example 6

[0104] Cerium-doped yttrium aluminum garnet (Ce:YAG) is provided as a fluorescent ceramic sheet, wherein the atomic percentage of Ce is 0.02%.

[0105] The fluorescent ceramic sheet was ultrasonically cleaned for 10 minutes each with dish soap, deionized water, acetone, and anhydrous ethanol, and then dried in an oven at 50°C.

[0106] The pre-cleaned fluorescent ceramic sheet was immersed in a phosphoric acid solution for etching, with the temperature of the phosphoric acid solution controlled at 200℃. After etching for 5 minutes, the fluorescent ceramic sheet was removed and ultrasonically cleaned for 5 minutes each with deionized water, acetone, and anhydrous ethanol. Then it was dried in an oven at 50℃ to serve as a fluorescent ceramic substrate.

[0107] The light-incident surface of the fluorescent ceramic sheet is finely polished.

[0108] Example 7

[0109] Cerium-doped yttrium aluminum garnet (Ce:YAG) is provided as a fluorescent ceramic sheet, wherein the atomic percentage of Ce is 0.02%.

[0110] The fluorescent ceramic sheet was ultrasonically cleaned for 10 minutes each with dish soap, deionized water, acetone, and anhydrous ethanol, and then dried in an oven at 50°C.

[0111] The pre-cleaned fluorescent ceramic sheet was immersed in a phosphoric acid solution for etching. The temperature of the phosphoric acid solution was controlled at 200℃. After etching for 10 minutes, the fluorescent ceramic sheet was removed and ultrasonically cleaned for 5 minutes each with deionized water, acetone, and anhydrous ethanol. Then it was dried in an oven at 50℃ to serve as a fluorescent ceramic substrate.

[0112] The light-incident surface of the fluorescent ceramic sheet is finely polished.

[0113] Example 8

[0114] Cerium-doped yttrium aluminum garnet (Ce:YAG) is provided as a fluorescent ceramic sheet, wherein the atomic percentage of Ce is 0.02%.

[0115] The fluorescent ceramic sheet was ultrasonically cleaned for 10 minutes each with dish soap, deionized water, acetone, and anhydrous ethanol, and then dried in an oven at 50°C.

[0116] The pre-cleaned fluorescent ceramic sheet was immersed in a phosphoric acid solution for etching. The temperature of the phosphoric acid solution was controlled at 200℃. After etching for 30 minutes, the fluorescent ceramic sheet was removed and ultrasonically cleaned for 5 minutes each with deionized water, acetone, and anhydrous ethanol. Then it was dried in an oven at 50℃ to serve as a fluorescent ceramic substrate.

[0117] The light-incident surface of the fluorescent ceramic sheet is finely polished.

[0118] Example 9

[0119] Cerium-doped yttrium aluminum garnet (Ce:YAG) is provided as a fluorescent ceramic sheet, wherein the atomic percentage of Ce is 0.02%.

[0120] The fluorescent ceramic sheet was ultrasonically cleaned for 10 minutes each with dish soap, deionized water, acetone, and anhydrous ethanol, and then dried in an oven at 50°C.

[0121] The pre-cleaned fluorescent ceramic sheet was immersed in a phosphoric acid solution for etching. The temperature of the phosphoric acid solution was controlled at 200℃. After etching for 50 minutes, the fluorescent ceramic sheet was removed and ultrasonically cleaned for 5 minutes each with deionized water, acetone, and anhydrous ethanol. Then it was dried in an oven at 50℃ to serve as a fluorescent ceramic substrate.

[0122] The light-incident surface of the fluorescent ceramic sheet is finely polished.

[0123] Example 10

[0124] The fluorescent ceramic substrate prepared in Example 8 was coated with a blue anti-reflection film on its light-incident surface to form a fluorescent ceramic. The fluorescent ceramic was then encapsulated on a blue LED chip to form a light-emitting device.

[0125] Example 11

[0126] The fluorescent ceramic substrate prepared in Example 1 was coated with a blue anti-reflection film on its light-incident surface to form a fluorescent ceramic. The fluorescent ceramic was then encapsulated on a blue LED chip to form a light-emitting device.

[0127] Example 12

[0128] The fluorescent ceramic substrate prepared in Example 6 was coated with a blue antireflective film on its light-incident surface to form a fluorescent ceramic. The fluorescent ceramic was then encapsulated on a blue LED chip to form a light-emitting device.

[0129] Comparative Example 1

[0130] Cerium-doped yttrium aluminum garnet (Ce:YAG) is provided as a fluorescent ceramic sheet, wherein the atomic percentage of Ce is 0.02%.

[0131] The fluorescent ceramic sheet was ultrasonically cleaned sequentially with detergent, deionized water, acetone, and anhydrous ethanol for 10 minutes each, then dried in an oven at 50°C. The light-incident surface of the fluorescent ceramic sheet was then finely polished to serve as the fluorescent ceramic substrate. A blue anti-reflective coating was deposited on its light-incident surface to form the fluorescent ceramic. This fluorescent ceramic was then encapsulated onto a blue LED chip to form a light-emitting device.

[0132] Experiment 1: The fluorescent ceramic substrates prepared in Comparative Example 1 and Examples 1-5 were used to observe their surface microstructure using scanning electron microscopy. The results can be seen in... Figure 4 The fluorescent ceramic substrates prepared in Examples 6-9 were examined using scanning electron microscopy to observe their surface microstructure. The results are shown in [the table / document / etc.]. Figure 5 .

[0133] Experiment 2: The transmittance of fluorescent ceramic substrates prepared using Comparative Example 1 and Example 8 under the same light source. The results can be seen in... Figure 6 .

[0134] Experiment 3: The surface roughness of the etched surfaces as described in Examples 1, 6, and 8 was tested, and the results are shown in Table 1. Additionally, the surface roughness of the incident surface after fine polishing was 13 nm.

[0135] Experiment 4: The luminous flux, correlated color temperature (CCT), and emission angle of the light-emitting devices prepared in Examples 10-12 and Comparative Example 1 were tested. The results are shown in Table 2. The 75% emission angle in Table 1 represents the angular range in which 75% of the luminous flux in the emitted light is located. A schematic diagram of the emission angle distribution of the light-emitting devices in Example 10 and Comparative Example 1 can be found in... Figure 7 .

[0136] Table 1

[0137]

[0138] Table 2

[0139]

[0140] Reference Figure 4 As shown, the surface of the fluorescent ceramic substrate in Comparative Example 1 is flat and without obvious depressions. From Example 1 to Example 3, the etching temperature during the preparation of the fluorescent ceramic substrate increased from 100℃ to 200℃, and the surface etching degree of the fluorescent ceramic substrate gradually increased. The density of the protrusions in the formed etching texture structure also gradually increased, but the distribution of the maximum radial width of the protrusions did not change much. In Examples 4 and 5, the etching temperatures during the preparation of the fluorescent ceramic substrate were 250℃ and 300℃, respectively, and the difference between the formed etching texture structure and that of Example 3 was relatively small.

[0141] Reference Figure 5 As shown, from Examples 6 to 8, the etching time for preparing the fluorescent ceramic substrate increased from 5 min to 30 min. The surface etching degree of the fluorescent ceramic substrate gradually increased, and the density of the protrusions in the formed etching texture structure also gradually increased, but the distribution of the maximum radial width of the protrusions did not change much. In Example 9, the etching time for preparing the fluorescent ceramic substrate was 50 min, and the difference between the formed etching texture structure and that of Example 8 was relatively small.

[0142] Reference Figure 6 As shown, the text in the left figure is located below the fluorescent ceramic substrate of Comparative Example 1. The text visible from below the fluorescent ceramic substrate of Comparative Example 1 is clearer. The text in the right figure is located below the fluorescent ceramic substrate of Example 8. The text visible from below the fluorescent ceramic substrate of Example 8 has slightly blurred edges and relatively low transmittance. This indicates that the surface roughness of the fluorescent ceramic substrate increases after etching, resulting in enhanced diffuse reflection of light and thus a decrease in transmittance.

[0143] Referring to Table 1, due to different specific corrosion conditions, the corrosion temperature of Example 1 was significantly lower, resulting in a milder corrosion effect. Consequently, the surface roughness of Example 1 was lower, at 215 nm. The surface roughness of Example 6 was relatively higher, at 262 nm. The surface roughness of Example 8 was significantly higher, reaching 310 nm.

[0144] Furthermore, referring to Table 2, the 75% emission angle of Comparative Example 1 reached 132.5°, which is significantly larger. Compared to Comparative Example 1, the emission angle of the light-emitting device prepared in Example 10 is only 125.3°, indicating that the light is more concentrated and emitted from the light-emitting surface. Moreover, Example 10 shows a significant increase in luminous flux and a significant decrease in color temperature, indicating that the "yellow edge effect" of Example 10 is significantly improved. Compared to Comparative Example 1, the "yellow edge effect" of Examples 11 and 12 is also improved, but the improvement is significantly less than that of Example 10. As can be seen from Table 1, this is mainly because the surface roughness of the ceramic substrate used in Example 10 is significantly higher, resulting in stronger diffuse reflection and a more significant improvement in the "yellow edge effect."

[0145] Reference Figure 7 As shown, Comparative Example 1 exhibits the highest relative emitted light intensity at approximately 53°, denoted as 1, while the relative emitted light intensity at 0° (i.e., perpendicular to the light-emitting surface) is only about 0.72, indicating that the light emission of the light-emitting device in Comparative Example 1 is relatively uneven. In contrast, Example 10 maintains a near-maximum relative emitted light intensity within the range of approximately 0° to ±40°. As the angle further increases, the relative emitted light intensity significantly decreases, indicating that the light from the light-emitting device in Example 10 is primarily concentrated on the light-emitting surface, with relatively low luminous flux emitted from the sides.

[0146] Please note that the above embodiments are for illustrative purposes only and are not intended to limit the scope of this document.

[0147] It should be understood that, unless otherwise expressly stated herein, there is no strict order in which the steps are performed, and these steps may be performed in other orders. Moreover, at least some steps in the preparation process may include multiple sub-steps or multiple stages, which are not necessarily completed at the same time, but may be performed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but may be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0148] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0149] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A fluorescent ceramic, characterized by, The invention includes a fluorescent ceramic substrate having an incident surface, an emitting surface, and a side surface. The incident surface and the emitting surface are disposed opposite to each other, and the side surface is located between the incident surface and the emitting surface. The emitting surface and at least a portion of the side surface have an etched texture structure formed by etching. The etched texture structure has a diffuse reflection effect on light. The surface roughness of the etched texture structure is 200 nm to 500 nm. The surface roughness of the incident surface is ≤20 nm.

2. The fluorescent ceramic according to claim 1, characterized in that, It also includes a functional film, which is stacked on the side of the light-incident surface away from the light-outceasing surface. The functional film is selected from blue anti-reflection film or anti-reflection film.

3. The fluorescent ceramic according to any one of claims 1 to 2, characterized in that, The fluorescent ceramic substrate is made of cerium-doped yttrium aluminum garnet.

4. A method for preparing fluorescent ceramics as described in any one of claims 1 to 3, characterized in that, The process includes the following steps: etching the light-emitting surface and at least part of the side surfaces of a fluorescent ceramic sheet using an etching solution containing phosphoric acid, and forming the fluorescent ceramic substrate based on the fluorescent ceramic sheet.

5. The method for preparing fluorescent ceramics according to claim 4, characterized in that, In the step of etching the light-emitting surface and at least part of the side surfaces of the fluorescent ceramic sheet, the temperature of the etching solution is controlled to be 100°C to 300°C; and / or, In the step of etching the light-emitting surface and at least part of the side surfaces of the fluorescent ceramic sheet, the etching time is controlled to be 1 min to 60 min.

6. The method for preparing fluorescent ceramics according to any one of claims 4 to 5, characterized in that, Before etching the light-emitting surface and at least part of the side surfaces of the fluorescent ceramic sheet, the light transmittance of the fluorescent ceramic sheet is >30%.

7. The method for preparing fluorescent ceramics according to any one of claims 4 to 5, characterized in that, It also includes a step of polishing the light-incident surface of the fluorescent ceramic sheet, wherein the surface roughness of the light-incident surface is ≤20nm during the polishing process.

8. A light-emitting device, characterized in that, The light-emitting device includes a light source and an encapsulation layer for encapsulating the light source. The encapsulation layer includes fluorescent ceramic as described in any one of claims 1 to 3, and the light source is disposed on the side of the fluorescent ceramic substrate away from the light-emitting surface.

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