LED chip and light-emitting device

Abstract

The invention provides an LED chip and a light-emitting device, and relates to the technical field of LEDs. The LED chip comprises: a substrate; the light-emitting functional layer is positioned on one side of the substrate; wherein one side, facing the light-emitting functional layer, of the substrate is provided with a plurality of first bulges; and the side wall of the first bulge is a concave cambered surface. On the basis of the morphology of the first protrusions, the effect of a concave lens can be achieved, the transmission direction of the parallel light is changed, and the parallel light is scattered in the axial direction, so that the axial light emitting efficiency of the LED chip is improved, and the light emitting efficiency of the LED chip is improved.

Description

Technical Field

[0001] This application relates to the field of LED technology, and in particular to an LED chip and a light-emitting device. Background Technology

[0002] With the widespread application of light-emitting diodes (LEDs) in various products such as general lighting, electrical components, and large backlight components, mini-light-emitting diodes (Mini-LEDs) and micro-light-emitting diodes (Micro-LEDs) are particularly favored in the field of display panels due to their advantages such as small size, high light source utilization, and long lifespan.

[0003] With the increasing application of Mini-LED / Micro-LED, improving its axial light output and enhancing product competitiveness has become an important issue in the industry. Summary of the Invention

[0004] In view of the above problems, this application provides an LED chip and a light-emitting device to improve the axial light emission of the LED chip. The specific solution is as follows:

[0005] A first aspect of this application provides an LED chip, the LED chip comprising:

[0006] Substrate;

[0007] A light-emitting functional layer located on one side of the substrate;

[0008] The substrate has a plurality of first protrusions on the side facing the light-emitting functional layer; the sidewalls of the first protrusions are concave arc surfaces.

[0009] Preferably, in the above-mentioned LED chip, the material of the first protrusion is the same as the material of the substrate;

[0010] Alternatively, the material of the first protrusion may be different from the material of the substrate.

[0011] Preferably, in the above-mentioned LED chip, when the material of the first protrusion is the same as the material of the substrate, the first protrusion and the substrate are an integral structure.

[0012] Preferably, in the above-described LED chip, when the material of the first protrusion is different from the material of the substrate, the LED chip further includes: a first bottom protrusion located between the first protrusion and the substrate;

[0013] The first bottom protrusion and the substrate are an integral structure.

[0014] Preferably, in the above-mentioned LED chip, in the first direction, the orthographic projection pattern of the first protrusion includes a first side surface and a second side surface; the first direction is parallel to the plane where the substrate is located;

[0015] The radius of curvature of the first side is R1, and the radius of curvature of the second side is R2;

[0016] Wherein, 0.75μm≤R1≤3μm, 0.75μm≤R2≤3μm.

[0017] Preferably, in the above-mentioned LED chip, the height of the first protrusion is H;

[0018] Where R≤H≤2×R; R is the smaller value between R1 and R2.

[0019] Preferably, in the above-mentioned LED chip, the distance between the bottoms of two adjacent first protrusions is L1, and the focal length of the first protrusion is f;

[0020] Where L1 = 2 × f.

[0021] Preferably, in the above-mentioned LED chip, a second protrusion is present between at least two adjacent first protrusions;

[0022] In a first direction, the orthographic projection pattern of the first protrusion is different from that of the second protrusion; the first direction is parallel to the plane in which the substrate is located.

[0023] Preferably, in the above-described LED chip, the second protrusion includes a first portion and a second portion; the first portion is located between the second portion and the substrate;

[0024] The first part is cylindrical in shape, and the surface of the second part is a convex arc surface.

[0025] Preferably, in the above-mentioned LED chip, the material of the first protrusion and / or the second protrusion is the same as the material of the substrate;

[0026] Alternatively, the materials of the first protrusion and the second protrusion may be different from the material of the substrate.

[0027] Preferably, in the above-described LED chip, when the material of the second protrusion is different from the material of the substrate,

[0028] The LED chip further includes a second bottom protrusion located between the second protrusion and the substrate;

[0029] The second bottom protrusion and the substrate are an integral structure.

[0030] Preferably, in the above-mentioned LED chip, the distance between the bottom of the adjacent first protrusion and the bottom of the second protrusion is L2, and the focal length of the first protrusion is f;

[0031] Where L2 = 2 × f.

[0032] Preferably, in the above-mentioned LED chip, the height of the second protrusion is greater than the height of the first protrusion.

[0033] Preferably, in the above-mentioned LED chip, the surface of the first protrusion facing away from the substrate is a plane, a concave surface, or a convex surface.

[0034] A second aspect of this application provides a light-emitting device, which includes any of the LED chips described above.

[0035] Preferably, in the above-mentioned light-emitting device, the light-emitting device includes a lighting device and / or a display device.

[0036] By employing the above technical solution, this application provides an LED chip and a light-emitting device. The LED chip includes: a substrate; a light-emitting functional layer located on one side of the substrate; wherein the side of the substrate facing the light-emitting functional layer has a plurality of first protrusions; the sidewalls of the first protrusions are concave arc surfaces. Based on the morphology of the first protrusions, they can act as concave lenses, thereby changing the transmission direction of parallel light and scattering it axially, thus improving the axial light emission of the LED chip and improving the light emission efficiency of the LED chip. Attached Figure Description

[0037] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. Throughout the drawings, the same or similar reference numerals denote the same or similar elements. It should be understood that the drawings are schematic, and the originals and elements are not necessarily drawn to scale.

[0038] Figure 1 This is a schematic diagram of the structure of an LED chip provided in an embodiment of the present invention;

[0039] Figure 2 This is a partial cross-sectional schematic diagram of a substrate in an LED chip provided by an embodiment of the present invention;

[0040] Figure 3 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided in an embodiment of the present invention;

[0041] Figure 4 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0042] Figure 5 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0043] Figure 6 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0044] Figure 7 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0045] Figure 8 This is a schematic diagram of total internal reflection of an LED chip provided in an embodiment of the present invention;

[0046] Figure 9 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0047] Figure 10 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0048] Figure 11 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0049] Figure 12 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0050] Figure 13 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0051] Figure 14 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0052] Figure 15 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0053] Figure 16 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0054] Figure 17 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0055] Figure 18 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0056] Figure 19This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0057] Figure 20 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0058] Figure 21 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0059] Figure 22 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0060] Figure 23 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention;

[0061] Figure 24 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided in an embodiment of the present invention. Detailed Implementation

[0062] The embodiments of this application are described below with reference to the accompanying drawings. The terminology used in the implementation section of this application is only for explaining specific embodiments and is not intended to limit the application. Those skilled in the art will recognize that, with technological advancements and the emergence of new scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0063] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0064] It should be noted that the directional terms appearing in this invention are based on the relative positional relationships shown in the accompanying drawings and should not be taken as absolute limitations on this application.

[0065] Various modifications and variations can be made to this invention without departing from its spirit or scope, as will be apparent to those skilled in the art. Therefore, this invention is intended to cover modifications and variations falling within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the embodiments provided in this invention can be combined with each other without contradiction.

[0066] refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of an LED chip provided in an embodiment of the present invention, with reference to... Figure 2 , Figure 2 This is a partial cross-sectional schematic diagram of a substrate in an LED chip provided by an embodiment of the present invention, with reference to... Figure 3 , Figure 3 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided in an embodiment of the present invention, with reference to... Figure 4 , Figure 4 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention. The LED chip provided by the embodiment of the present invention can be a Mini-LED or a Micro-LED, and the LED chip includes: a substrate 11.

[0067] The light-emitting functional layer 12 is located on one side of the substrate 11.

[0068] The substrate 11 has a plurality of first protrusions 13 on the side facing the light-emitting functional layer 12; the sidewalls of the first protrusions 13 are concave arc surfaces.

[0069] Specifically, in the embodiments of the present invention, the material of the substrate 11 includes, but is not limited to, sapphire, silicon, silicon carbide, gallium nitride, or zinc oxide.

[0070] The light-emitting functional layer 12 includes, but is not limited to, an N-type semiconductor layer 121, a multiple quantum well layer 122, and a P-type semiconductor layer 123 stacked sequentially, wherein the N-type semiconductor layer 121 includes, but is not limited to, an N-type GaN layer, and the P-type semiconductor layer 123 includes, but is not limited to, a P-type GaN layer.

[0071] The first protrusion 13 has a concave arc surface on its sidewall. Based on the shape of the first protrusion 13, it can function as a concave lens, such as... Figure 2 As shown, this can change the direction of light transmission of parallel light, causing it to scatter axially, thereby improving the axial light output of the LED chip and thus increasing the light output efficiency of the LED chip.

[0072] In an optional embodiment of the present invention, the material of the first protrusion 13 is the same as the material of the substrate 11.

[0073] Specifically, in embodiments of the present invention, when the material of the first protrusion 13 is the same as the material of the substrate 11, the methods for forming the first protrusion 13 include at least the following two:

[0074] Method 1: A photoresist layer is formed on the substrate 11; this includes, but is not limited to, using nanoimprint lithography or photolithography to form a photoresist mask; this includes, but is not limited to, using a dry etching process to etch the substrate 11 using the photoresist mask to form a substrate 11 with a first protrusion 13, where the first protrusion 13 and the substrate 11 are an integral structure and there is no interface between the first protrusion 13 and the substrate 11. Figures 2-4 As shown.

[0075] Method 2: A dielectric layer of the same material as the substrate 11 is formed on the substrate 11, and a photoresist layer is formed on the side of the dielectric layer away from the substrate 11; including but not limited to using nanoimprinting technology or photolithography to form a photoresist mask; including but not limited to using a dry etching process to etch the dielectric layer using the photoresist mask to form a substrate 11 with a first protrusion 13, wherein the first protrusion 13 is made of the dielectric layer and is not an integral structure with the substrate 11, and there is an interface between the first protrusion 13 and the substrate 11.

[0076] In an optional embodiment of the present invention, reference is made to... Figure 5 , Figure 5 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention, with reference to... Figure 6 , Figure 6 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention, with reference to... Figure 7 , Figure 7 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention. The material of the first protrusion 13 is different from the material of the substrate 11.

[0077] It should be noted that, Figures 5-7 The different shapes are filled in to represent the different materials.

[0078] Specifically, in embodiments of the present invention, when the material of the first protrusion 13 is different from the material of the substrate 11, the first protrusion 13 can be formed in the following ways:

[0079] A heterogeneous layer of a different material from the substrate 11 is formed on the substrate 11, and a photoresist layer is formed on the side of the heterogeneous layer away from the substrate 11; including but not limited to using nanoimprinting technology or photolithography to form a photoresist mask from the photoresist layer; including but not limited to using a dry etching process to etch the heterogeneous layer using the photoresist mask to form a substrate 11 with a first protrusion 13, wherein the first protrusion 13 is made of the heterogeneous layer and is not an integral structure with the substrate 11, and there is an interface between the first protrusion 13 and the substrate 11.

[0080] The principle of total internal reflection is introduced below. The basic condition for total internal reflection is that light enters from an optically denser medium and then from an optically less dense medium. Based on a standard LED chip, when the material of the first protrusion 13 is different from the material of the substrate 11, it is necessary to ensure that the refractive index of the material of the first protrusion 13 is less than the refractive index of the semiconductor layer in the light-emitting functional layer 12. For example, when the semiconductor layer in the light-emitting functional layer 12 is a GaN layer, the material of the first protrusion 13 can be SiO2. When the material of the first protrusion 13 is the same as the material of the substrate 11, it is necessary to ensure that the refractive index of the material of the substrate 11 is less than the refractive index of the semiconductor layer in the light-emitting functional layer 12. For example, when the semiconductor layer in the light-emitting functional layer 12 is a GaN layer, the material of the substrate 11 can be sapphire.

[0081] The following comparison will provide further explanation:

[0082] refer to Figure 8 , Figure 8 This is a schematic diagram of total internal reflection of an LED chip provided in an embodiment of the present invention.

[0083] by Figures 2-4 Taking the substrate structure shown as an example, the first protrusion 13 and the substrate 11 are made of the same material, sapphire, with a refractive index of 1.76; the semiconductor layer of the LED chip is made of GaN.

[0084] by Figures 5-7 Taking the substrate structure shown as an example, the materials of the first protrusion 13 and the substrate 11 are different. The material of the first protrusion 13 is SiO2 material, and the refractive index of SiO2 material is less than that of sapphire material; the material of the semiconductor layer of the LED chip is GaN material.

[0085] As described above, the basic condition for total internal reflection is that light travels from an optically denser medium to an optically less dense medium. Figure 8 As shown, there exists n GaN ×sinθ c =n1×sinθ t The relationship between n GaN n represents the refractive index of the GaN material, and n1 represents the refractive index of the material of the first protrusion 13.

[0086] Calculations show that, with Figures 2-4 The critical angle θ of the LED chip fabricated using the substrate structure shown is... c ≈47.1°, with Figures 5-7 The critical angle θ of the LED chip fabricated using the substrate structure shown is... c ≈37.5°.

[0087] Therefore, it can be concluded that, with Figures 5-7The LED chip fabricated using the substrate structure shown has a larger angle for total internal reflection and a stronger reflection effect.

[0088] Since the material of the first protrusion 13 is different from that of the substrate 11, the material of the first protrusion 13 can be flexibly selected and is not limited by the material of the substrate 11. Therefore, a material with a smaller refractive index than the substrate 11 can be selected to prepare the first protrusion 13, thereby making the angle of total internal reflection larger and the reflection effect stronger.

[0089] From the perspective of reflectivity, for a standard LED chip, it is desirable for the substrate 11 to have a higher reflectivity. This is achieved by appropriately selecting the material of the substrate 11 or the material of the first protrusion 13, ensuring that the refractive index of the material is lower than that of the semiconductor layer material, and based on the reflectivity relationship (n2-n1) / (n2+n1), maximizing this value as much as possible. Here, n2 represents the refractive index of the semiconductor layer material of the LED chip.

[0090] For flip-chip LEDs, by reasonably selecting the material of substrate 11 or the material of the first protrusion 13, and on the premise that the refractive index of the material is greater than the refractive index of the semiconductor layer material, the reflectivity (n2-n1) / (n2+n1) is minimized as much as possible.

[0091] In an optional embodiment of the present invention, reference is made to... Figure 9 , Figure 9 This is a partial cross-sectional schematic diagram of a substrate in an LED chip according to another embodiment of the present invention. The LED chip further includes: a first bottom protrusion 14 located between the first protrusion 13 and the substrate 11; the first bottom protrusion 14 and the substrate 11 are an integral structure.

[0092] Specifically, in the embodiment of the present invention, when the materials of the first protrusion 13 and the substrate 11 are different, the substrate 11 can be over-etched during the preparation of the first protrusion 13 to form the first bottom protrusion 14, so as to ensure that the area between two adjacent first protrusions 13 can effectively expose part of the surface of the substrate 11, thereby improving the epitaxial stability of the light-emitting functional layer 12.

[0093] It should be noted that whether the LED chip has a first bottom protrusion 14 depends mainly on the stability of the manufacturing process. If it is desired that no material used to prepare the first protrusion 13 remains in the corresponding area of ​​the substrate 11, forming the first bottom protrusion 14 will be more stable. However, due to the light reflection capability, the larger the surface area of ​​the first protrusion 13, the higher the reflectivity.

[0094] Furthermore, since the material of the first protrusion 13 is different from that of the substrate 11, selective epitaxial growth can be achieved, effectively improving the crystal quality of the epitaxial layer and increasing the luminous efficacy of the LED chip by about 1.5%.

[0095] In an optional embodiment of the present invention, such as Figure 2 As shown, in the first direction, the orthographic projection of the first protrusion 13 includes a first side surface 131 and a second side surface 132; the first direction is parallel to the plane where the substrate 11 is located.

[0096] The radius of curvature of the first side surface 131 is R1, and the radius of curvature of the second side surface 132 is R2.

[0097] Wherein, 0.75μm≤R1≤3μm, 0.75μm≤R2≤3μm.

[0098] Specifically, in this embodiment of the invention, the height of the first protrusion 13 is H; where R≤H≤2×R; R is the smaller value between R1 and R2. For example, when R1<R2, then R1≤H≤2×R1.

[0099] In this embodiment of the invention, by comprehensively considering the relationship between R1, R2 and H, the light processing effect of the first protrusion 13 is maximized, thereby improving the photoelectric performance of the LED chip.

[0100] In an optional embodiment of the present invention, such as Figure 2 As shown, the distance between the bottoms of two adjacent first protrusions 13 is L1, and the focal length of the first protrusion 13 is f; where L1 = 2 × f.

[0101] Specifically, in this embodiment of the invention, the principle of a concave lens is used to diverge parallel light and change it into axial light emission. By making L1=2×f, more parallel light divergence can be achieved. Through testing, it was found that the axial light lop can be increased by 0.5%.

[0102] When R1≠R2, it is necessary to satisfy 1 / f=(n1-1)×(1 / R1-1 / R2); when R1=R2, it is necessary to satisfy f=R1 / (2×(n1-1)).

[0103] In an optional embodiment of the present invention, the surface of the first protrusion 13 facing away from the substrate 11 is a plane, a concave surface, or a convex surface.

[0104] Specifically, in the embodiments of the present invention, such as Figure 2 and Figure 5 As shown, the surface of the first protrusion 13 facing away from the substrate 11 is planar; Figure 3 and Figure 6As shown, the surface of the first protrusion 13 facing away from the substrate 11 is concave; as Figure 4 and Figure 7 As shown, the surface of the first protrusion 13 facing away from the substrate 11 is convex.

[0105] For a standard LED chip, when the surface of the first protrusion 13 facing away from the substrate 11 is concave or convex, it has a larger reflective area compared to a flat surface, which can improve its reflectivity and thus improve the photoelectric performance of the LED chip.

[0106] In an optional embodiment of the present invention, reference is made to... Figure 10 , Figure 10 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention. In the LED chip provided by this embodiment of the present invention, at least two adjacent first protrusions 13 have a second protrusion 15 between them.

[0107] In a first direction, the orthographic projection of the first protrusion 13 is different from the orthographic projection of the second protrusion 15; the first direction is parallel to the plane where the substrate 11 is located.

[0108] Specifically, in this embodiment of the invention, various protrusions of different shapes are provided on the surface of the substrate 11 facing the light-emitting functional layer 12 to improve the reflection and / or refraction of light, thereby maximizing the axial light emission of the LED chip and thus improving the light emission efficiency of the LED chip.

[0109] Optional, such as Figure 10 As shown, the second protrusion 15 includes a first portion 151 and a second portion 152; the first portion 151 is located between the second portion 152 and the substrate 11.

[0110] The first part 151 is cylindrical in shape, and the surface of the second part 152 is a convex arc surface.

[0111] It should be noted that, Figure 10 The diagram only shows one shape of the second protrusion 15, but obviously the shape of the second protrusion 15 can also be other shapes.

[0112] Furthermore, the shape of the protrusions on the side surface of the substrate 11 facing the light-emitting functional layer 12 is not limited to two types, but can be more than two types. By combining various different shapes, the reflection and / or refraction of light can be further improved, thereby maximizing the axial light emission of the LED chip and thus improving the light emission efficiency of the LED chip.

[0113] Optional, such as Figure 10As shown, the distance between the bottom of the adjacent first protrusion 13 and the bottom of the second protrusion 15 is L2, and the focal length of the first protrusion 13 is f; where L2 = 2 × f.

[0114] Specifically, in this embodiment of the invention, the principle of a concave lens is used in combination with other shaped protrusions to maximize the divergence of parallel light, converting parallel light into axial light emission. By making L2=2×f, more parallel light can be diffused, thereby maximizing the axial light emission of the LED chip and thus improving the light emission efficiency of the LED chip.

[0115] Optionally, the material of the first protrusion 13 and / or the second protrusion 15 is the same as the material of the substrate 11.

[0116] Alternatively, the materials of the first protrusion 13 and the second protrusion 15 may be different from the material of the substrate 11.

[0117] like Figure 10 As shown, the materials of the first protrusion 13 and the second protrusion 15 are the same as the material of the substrate 11.

[0118] refer to Figure 11 , Figure 11 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention. The material of the first protrusion 13 is different from that of the substrate 11, and the material of the second protrusion 15 is the same as that of the substrate 11.

[0119] refer to Figure 12 , Figure 12 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention. The material of the first protrusion 13 is different from that of the substrate 11, the material of the second protrusion 15 is the same as that of the substrate 11, and there is a first bottom protrusion 14 between the first protrusion 13 and the substrate 11.

[0120] refer to Figure 13 , Figure 13 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention. The material of the first protrusion 13 is the same as that of the substrate 11, and the material of the second protrusion 15 is different from that of the substrate 11.

[0121] refer to Figure 14 , Figure 14 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention. The materials of the first protrusion 13 and the second protrusion 15 are both different from the material of the substrate 11.

[0122] refer to Figure 15 , Figure 15This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention. The materials of the first protrusion 13 and the second protrusion 15 are different from the material of the substrate 11, and there is a first bottom protrusion 14 between the first protrusion 13 and the substrate 11.

[0123] In an optional embodiment of the present invention, reference is made to... Figure 16 , Figure 16 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention; see reference. Figure 17 , Figure 17 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention; see reference. Figure 18 , Figure 18 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention. In the LED chip provided by this embodiment of the present invention, when the material of the second protrusion 15 is different from the material of the substrate 11, the LED chip further includes a second bottom protrusion 16 located between the second protrusion 15 and the substrate 11.

[0124] The second bottom protrusion 16 and the substrate 11 are an integral structure.

[0125] Specifically, in the embodiment of the present invention, when the materials of the second protrusion 15 and the substrate 11 are different, the substrate 11 can be over-etched during the preparation of the second protrusion 16 to form the second bottom protrusion 16, so as to ensure that the area between two adjacent protrusions can effectively expose part of the surface of the substrate 11, thereby improving the epitaxial stability of the light-emitting functional layer 12.

[0126] It should be noted that whether the LED chip has a second bottom protrusion 16 depends mainly on the stability of the manufacturing process. If it is desired that no material for preparing the protrusion remains in the corresponding area of ​​the substrate 11, forming the second bottom protrusion 16 will be more stable. However, due to the light reflection capability, the larger the surface area of ​​the second protrusion 15, the higher the reflectivity.

[0127] Furthermore, since the material of the second protrusion 15 is different from that of the substrate 11, selective epitaxial growth can be achieved, effectively improving the crystal quality of the epitaxial layer and enhancing the luminous efficiency of the LED chip.

[0128] like Figure 16 As shown, the material of the first protrusion 13 is the same as that of the substrate 11, the material of the second protrusion 15 is different from that of the substrate 11, and there is a second bottom protrusion 16 between the second protrusion 15 and the substrate 11.

[0129] like Figure 17As shown, the materials of the first protrusion 13 and the second protrusion 15 are different from the material of the substrate 11, and the second protrusion 15 has a second bottom protrusion 16 between it and the substrate 11.

[0130] like Figure 18 As shown, the materials of the first protrusion 13 and the second protrusion 15 are different from the material of the substrate 11, and the first protrusion 13 has a first bottom protrusion 14 between it and the substrate 11, and the second protrusion 15 has a second bottom protrusion 16 between it and the substrate 11.

[0131] In an optional embodiment of the present invention, reference is made to... Figure 19 , Figure 19 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention; see reference. Figure 20 , Figure 20 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention; see reference. Figure 21 , Figure 21 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention. In the LED chip provided by the embodiment of the present invention, the height of the second protrusion 15 is greater than the height of the first protrusion 13.

[0132] like Figures 16-18 As shown, in the LED chip provided in this embodiment of the invention, the height of the second protrusion 15 is equal to the height of the first protrusion 13.

[0133] refer to Figure 22 , Figure 22 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention; see reference. Figure 23 , Figure 23 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention; see reference. Figure 24 , Figure 24 This is a partial cross-sectional schematic diagram of the substrate in another LED chip provided by an embodiment of the present invention. In the LED chip provided by the embodiment of the present invention, the height of the second protrusion 15 is less than the height of the first protrusion 13.

[0134] Specifically, in this embodiment of the invention, when the protrusion on the side of the substrate 11 facing the light-emitting functional layer 12 has multiple protrusions of different shapes, the heights of the protrusions of different shapes can be the same or different.

[0135] However, it should be noted that, as Figures 19-21 As shown, when the height of the second protrusion 15 is greater than the height of the first protrusion 13, the optical path can be changed again. Compared with the other two schemes, the axial light of the LED chip can be increased by 1.5%.

[0136] It should be further noted that the higher the height of the protrusion that is different from the substrate 11 material, the stronger its light reflection effect will be.

[0137] In an optional embodiment of the present invention, when the substrate 11 has only the first protrusion 13 or only the same shape protrusion on the side surface facing the light-emitting functional layer 12, the shape parameters of the different protrusions can also be different to achieve different effects and diversify the structure.

[0138] Based on the above embodiments of the present invention, another embodiment of the present invention also provides a light-emitting device, which includes the LED chip provided in the above embodiments.

[0139] For example, the light-emitting device includes a lighting device and / or a display device.

[0140] The present invention has provided a detailed description of an LED chip and a light-emitting device. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

[0141] It should be noted that each embodiment in this specification focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0142] It should also be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that elements inherent to a process, method, article, or apparatus that comprises a list of elements, or elements inherent to such processes, methods, articles, or apparatus, are also included. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0143] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An LED chip, characterized in that, The LED chip includes: Substrate; A light-emitting functional layer located on one side of the substrate; The substrate has a plurality of first protrusions on the side facing the light-emitting functional layer; the sidewalls of the first protrusions are concave arc surfaces.

2. The LED chip according to claim 1, characterized in that, The material of the first protrusion is the same as the material of the substrate; Alternatively, the material of the first protrusion may be different from the material of the substrate.

3. The LED chip according to claim 2, characterized in that, When the material of the first protrusion is the same as the material of the substrate, the first protrusion and the substrate are an integral structure.

4. The LED chip according to claim 2, characterized in that, When the material of the first protrusion is different from the material of the substrate, the LED chip further includes: a first bottom protrusion located between the first protrusion and the substrate; The first bottom protrusion and the substrate are an integral structure.

5. The LED chip according to claim 1, characterized in that, In a first direction, the orthographic projection of the first protrusion includes a first side surface and a second side surface; the first direction is parallel to the plane containing the substrate. The radius of curvature of the first side is R1, and the radius of curvature of the second side is R2; Wherein, 0.75μm≤R1≤3μm, 0.75μm≤R2≤3μm.

6. The LED chip according to claim 5, characterized in that, The height of the first protrusion is H; Where R≤H≤2×R; R is the smaller value between R1 and R2.

7. The LED chip according to claim 1, characterized in that, The distance between the bottoms of two adjacent first protrusions is L1, and the focal length of the first protrusion is f; Where L1 = 2 × f.

8. The LED chip according to claim 1, characterized in that, At least two adjacent first protrusions are separated by a second protrusion; In the first direction, the orthographic projection of the first protrusion is different from that of the second protrusion; The first direction is parallel to the plane in which the substrate is located.

9. The LED chip according to claim 8, characterized in that, The second protrusion includes a first portion and a second portion; the first portion is located between the second portion and the substrate; The first part is cylindrical in shape, and the surface of the second part is a convex arc surface.

10. The LED chip according to claim 8, characterized in that, The material of the first protrusion and / or the second protrusion is the same as the material of the substrate; Alternatively, the materials of the first protrusion and the second protrusion may be different from the material of the substrate.

11. The LED chip according to claim 10, characterized in that, When the material of the second protrusion is different from the material of the substrate. The LED chip further includes a second bottom protrusion located between the second protrusion and the substrate; The second bottom protrusion and the substrate are an integral structure.

12. The LED chip according to claim 8, characterized in that, The distance between the bottom of the adjacent first protrusion and the bottom of the second protrusion is L2, and the focal length of the first protrusion is f; Where L2 = 2 × f.

13. The LED chip according to claim 8, characterized in that, The height of the second protrusion is greater than the height of the first protrusion.

14. The LED chip according to claim 1, characterized in that, The surface of the first protrusion facing away from the substrate is a plane, a concave surface, or a convex surface.

15. A light-emitting device, characterized in that, The light-emitting device includes the LED chip according to any one of claims 1-14.

16. The light-emitting device according to claim 15, characterized in that, The light-emitting device includes lighting equipment and / or display equipment.

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