LED chip and lighting equipment
By covering the surface of the epitaxial structure of the LED chip with an optical film, the problem of low light extraction efficiency of the LED chip is solved, and the transmission of blue light and the reflection of yellow and red light are enhanced, thereby improving the light extraction efficiency.
Patent Information
- Application Number
- CN202520136820.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-21
- Publication Date
- 2026-01-23
- Estimated Expiration
- 2035-01-21
AI Technical Summary
In existing technologies, the light extraction efficiency of LED chips is relatively low, mainly due to total internal reflection caused by the difference in refractive index between air and semiconductor materials. This results in most photons being absorbed as heat and unable to be effectively emitted.
An optical film is coated on the surface of the epitaxial structure of an LED chip. The optical film consists of alternating stacked first and second film layers. The first film layer has high transmittance for blue light and high reflectivity for yellow and red light. The light extraction efficiency is improved by optimizing the film layer parameters.
It improves the white light extraction efficiency of LED chips, enhances blue light transmittance, and increases the reflection of yellow and red light, thereby improving light extraction efficiency.
Smart Images
Figure CN223829722U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of semiconductor devices, in particular to an LED chip and a lighting device. BACKGROUND
[0002] White light LED (Light Emitting Diode) chip rapidly replaces traditional incandescent lamp to become the fourth generation of green lighting light source due to the advantages of energy saving, environmental protection, small size, high efficiency and long service life. The white light LED chip mainly emits white light by blue light exciting YAG fluorescent powder. Improving the light emitting efficiency of the white light LED chip has been the mission of LED practitioners, which is generally improved from internal quantum efficiency, electrical efficiency, light extraction efficiency and packaging efficiency.
[0003] Before the LED chip is packaged, due to the large difference between the refractive index of air and the refractive index of semiconductor material, total reflection will occur between the semiconductor and air interface. Only a small part of the light of the active region can be emitted to the free space, and the rest will be left in the device. After multiple total reflections, the metal electrode, semiconductor and substrate will absorb these photons and then convert them into heat, which greatly reduces the light emitting efficiency of the LED chip.
[0004] Therefore, how to improve the light emitting efficiency of the LED chip is a technical problem to be solved by those skilled in the art. SUMMARY
[0005] In view of the above problems, the present application provides an LED chip and a lighting device, which realize the purpose of improving the light emitting efficiency of the LED chip. The specific scheme is as follows:
[0006] The first aspect of the present application provides an LED chip, which comprises:
[0007] a substrate;
[0008] an epitaxial structure located on one side of the substrate; the epitaxial structure comprises an N-type semiconductor layer, a multi-quantum well layer and a P-type semiconductor layer which are sequentially stacked on one side of the substrate;
[0009] an optical film layer located on one side of the substrate and covering the epitaxial structure; the optical film layer comprises first film layers and second film layers which are alternately stacked, and the refractive indices of the first film layers and the second film layers are different;
[0010] The optical film layer has a first transmittance for blue light generated by the LED chip, a second transmittance for yellow light generated by the LED chip, and a third transmittance for red light generated by the LED chip. The first transmittance is greater than the second transmittance, and the first transmittance is greater than the third transmittance.
[0011] Preferably, in the above LED chip, the first film layer has a refractive index less than the refractive index of the second film layer.
[0012] Preferably, in the above LED chip, the LED chip further comprises: an insulating layer located on one side of the substrate and covering the epitaxial structure; the insulating layer is located between the epitaxial structure and the optical film layer.
[0013] The epitaxial structure further comprises: a first electrode and a second electrode; the first electrode is electrically connected to the N-type semiconductor layer, and the second electrode is electrically connected to the P-type semiconductor layer.
[0014] The LED chip further comprises: a first pad, a second pad, and a first through hole penetrating the insulating layer and the optical film layer; a part of the first through hole exposes a part of the surface of the first electrode, and another part of the first through hole exposes a part of the surface of the second electrode; the first pad is electrically connected to the first electrode, and the second pad is electrically connected to the second electrode.
[0015] Preferably, in the above LED chip, the thickness of the insulating layer ranges from 500 angstroms to 10,000 angstroms.
[0016] Preferably, in the above LED chip, the LED chip further comprises:
[0017] a first pad, a second pad, and a second through hole penetrating the optical film layer; a part of the second through hole exposes a part of the surface of the N-type semiconductor layer, and another part of the second through hole exposes a part of the surface of the P-type semiconductor layer; the first pad is electrically connected to the N-type semiconductor layer, and the second pad is electrically connected to the P-type semiconductor layer.
[0018] Preferably, in the above LED chip, the LED chip further comprises:
[0019] a buffer layer located between the substrate and the N-type semiconductor layer.
[0020] Preferably, in the above LED chip, the epitaxial structure further comprises:
[0021] a transparent conductive layer located on the side of the P-type semiconductor layer away from the substrate.
[0022] Preferably, in the LED chip, the LED chip further comprises:
[0023] a DBR layer located on the side of the substrate away from the N-type semiconductor layer.
[0024] Preferably, in the LED chip, in the direction away from the epitaxial structure, the optical film layer comprises a first part, a second part and a third part;
[0025] the optical thickness of the first film layer in the first part is less than 0.1λ1, and the optical thickness of the second film layer in the first part is less than 0.1λ1;
[0026] the optical thickness of the first film layer in the second part satisfies 2n1d1+k=1 / 2λ1, and the optical thickness of the second film layer in the second part satisfies 2n2d2+k=1 / 2λ1;
[0027] the optical thickness of the first film layer in the third part satisfies 2n3d3=λ2 / 2, and the optical thickness of the second film layer in the third part satisfies 2n4d4=λ2 / 2;
[0028] wherein λ1 represents the wavelength of light, the value of λ1 is 448 nm; λ2 represents the wavelength of light, the value of λ2 is 570 nm; n1 represents the refractive index of the first film layer in the second part; d1 represents the optical thickness of the first film layer in the second part; n2 represents the refractive index of the second film layer in the second part; d2 represents the optical thickness of the second film layer in the second part; n3 represents the refractive index of the first film layer in the third part; d3 represents the optical thickness of the first film layer in the third part; n4 represents the refractive index of the second film layer in the third part; d4 represents the optical thickness of the second film layer in the third part; and k is an integer.
[0029] The second aspect of the present application provides a lighting device, the lighting device comprising the LED chip according to any one of the above.
[0030] By employing the above technical solution, this application provides an LED chip and a lighting device, wherein an optical film layer is coated on the surface of an epitaxial structure; the optical film layer includes a first film layer and a second film layer alternately stacked, the first film layer and the second film layer having different refractive indices; wherein the transmittance of the optical film layer for blue light generated by the LED chip is a first transmittance, the transmittance of the optical film layer for yellow light generated by the LED chip is a second transmittance, and the transmittance of the optical film layer for red light generated by the LED chip is a third transmittance; the first transmittance is greater than the second transmittance, and the first transmittance is greater than the third transmittance; in other words, coating the surface of the epitaxial structure with an optical film layer makes it exhibit the effect of increasing the transmittance of blue light generated by the LED chip and increasing the reflectivity of yellow and red light generated by the LED chip, thereby improving the light extraction efficiency of white light from the LED chip, thereby achieving the purpose of improving the light extraction efficiency of the LED chip. Attached Figure Description
[0031] 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.
[0032] Figure 1 This is a schematic diagram of the structure of an LED chip provided in an embodiment of the present utility model;
[0033] Figure 2 This is a schematic diagram of another LED chip structure provided in an embodiment of the present utility model;
[0034] Figure 3 A schematic diagram of the structure of an optical film layer provided in an embodiment of this utility model;
[0035] Figure 4 This is a schematic diagram of the structure of another LED chip provided in an embodiment of the present utility model;
[0036] Figure 5 This is a schematic diagram of the structure of another LED chip provided in an embodiment of the present utility model;
[0037] Figure 6 This is a schematic diagram of the structure of another LED chip provided in an embodiment of the present utility model. Detailed Implementation
[0038] 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.
[0039] The applicant has discovered the following existing technical solutions for improving the light extraction efficiency of LED chips:
[0040] Existing technical solution 1: Set up an omni-directional reflector (ODR), which is composed of a dielectric and a metal. It can have high reflectivity for light emitted from the LED chip in any direction, so that the LED chip has high light extraction efficiency.
[0041] Existing technical solution 2: Set up a distributed Bragg reflector, which is a layered structure formed by alternating and periodically growing two materials with different refractive indices. When the light emitted by the active layer of the LED chip passes through it, it will be reflected onto the light-emitting surface, thus improving the light-emitting efficiency of the LED chip.
[0042] Existing technical solution 3: Using antireflective coating technology to improve light extraction efficiency by reducing the Fresnel effect between the LED chip and the air interface.
[0043] Based on the existing technical solution one, the omnidirectional reflector is composed of a medium and metal, and it can only reflect light. It cannot simultaneously transmit blue light, reflect red light, and reflect yellow light.
[0044] Based on the existing technical solution 2, the structure of the distributed Bragg reflector is formed by alternating and periodically growing two materials with different refractive indices. It is generally designed to reflect light of 400nm-700nm, which cannot increase the transmittance of blue light, while also reflecting the white light emitted by the external phosphor.
[0045] Based on the existing technical solution three, the antireflection coating technology can only increase the transmittance of blue light emitted by the LED chip, but cannot reflect the white light emitted by the external phosphor.
[0046] Based on this, the present application provides an LED chip and a lighting device. An optical film layer is coated on the surface of the LED chip's epitaxial structure, which enhances the transmittance of blue light generated by the LED chip and increases the reflectivity of yellow and red light generated by the LED chip, thereby improving the light extraction efficiency of white light from the LED chip and thus achieving the goal of improving the light extraction efficiency of the LED chip. The yellow and red light generated by the LED chip are typically produced by phosphors within the LED chip.
[0047] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0048] It should be noted that the directional terms appearing in this utility model are based on the relative positional relationships shown in the accompanying drawings and should not be taken as absolute limitations on this application.
[0049] 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 schematic diagram of another LED chip provided in an embodiment of the present invention, with reference to... Figure 3 , Figure 3 A schematic diagram of an optical film layer provided in an embodiment of this utility model. The LED chip provided in this embodiment of the utility model includes:
[0050] Substrate 11.
[0051] An epitaxial structure located on one side of the substrate 11; the epitaxial structure includes an N-type semiconductor layer 12, a multiple quantum well layer 13, and a P-type semiconductor layer 14, which are stacked sequentially on one side of the substrate 11.
[0052] An optical film layer 15 is located on one side of the substrate 11 and covers the epitaxial structure; the optical film layer 15 includes a first film layer 151 and a second film layer 152 that are alternately stacked, and the first film layer 151 and the second film layer 152 have different refractive indices.
[0053] Wherein, the transmittance of the optical film layer 15 to the blue light generated by the LED chip is a first transmittance, the transmittance of the optical film layer 15 to the yellow light generated by the LED chip is a second transmittance, and the transmittance of the optical film layer 15 to the red light generated by the LED chip is a third transmittance; the first transmittance is greater than the second transmittance, and the first transmittance is greater than the third transmittance.
[0054] Specifically, in this embodiment of the invention, the refractive index of the first film layer 151 is less than that of the second film layer 152. An optical film layer 15 is covered on the surface of the epitaxial structure, which makes it exhibit the effect of increasing the transmittance of blue light generated by the LED chip and increasing the reflectivity of yellow and red light generated by the LED chip. That is, the first transmittance is greater than the second transmittance and the first transmittance is greater than the third transmittance, thereby improving the light extraction efficiency of white light of the LED chip, so as to improve the light output efficiency of the LED chip.
[0055] The first film layer 151 and the second film layer 152 can be oxide films or nitride films made of different materials, with different refractive indices and optical transparency, such as SiO2, SiN, and SiO2. x N y Two or more of the oxides or nitrides of TiO2, Si3N4, Al2O3, TiN, AlN, ZrO2, TiAlN or TiSiN.
[0056] It should be noted that the materials selected for forming the optical film layers in this embodiment of the invention should have advantages such as high transparency, low extinction coefficient, high mechanical strength, good chemical stability, large refractive index difference, and strong resistance to high-energy radiation. Due to their advantages such as high transmittance, easy deposition, and relatively large refractive index difference, SiO2 and TiO2 materials are preferred in actual production. The first film layer 151 is preferably a SiO2 film layer with a refractive index of approximately 1.47, and the second film layer 152 is preferably a TiO2 film layer with a refractive index of approximately 2.55. It should also be noted that the first and second film layers are not limited to the aforementioned SiO2 and TiO2 layers.
[0057] By optimizing the periodicity ratio of the optical film layer 15, as well as parameters such as the number of film layers and thickness, it can be made to exhibit the effects of enhancing the transmission of blue light generated by the LED chip and enhancing the reflection of yellow and red light generated by the LED chip, thereby improving the light extraction efficiency of white light from the LED chip and thus achieving the goal of improving the light output efficiency of the LED chip.
[0058] In an optional embodiment of this utility model, such as Figure 3 As shown, in the direction away from the epitaxial structure, the optical film layer 15 includes a first portion 15A, a second portion 15B, and a third portion 15C.
[0059] The optical thickness of the first film layer 151 in the first part 15A is less than 0.1λ1, and the optical thickness of the second film layer 152 in the first part 15A is less than 0.1λ1.
[0060] The optical thickness of the first film layer 151 in the second part 15B satisfies 2n1d1+k=1 / 2λ1, and the optical thickness of the second film layer 152 in the second part 15B satisfies 2n2d2+k=1 / 2λ1.
[0061] The optical thickness of the first film layer 151 in the third part 15C satisfies 2n3d3=λ2 / 2, and the optical thickness of the second film layer 152 in the third part 15C satisfies 2n4d4=λ2 / 2.
[0062] Wherein, λ1 represents the wavelength of light, with a value of 448 nm; λ2 represents the wavelength of light, with a value of 570 nm; n1 represents the refractive index of the first film layer 151 in the second part 15B; d1 represents the optical thickness of the first film layer 151 in the second part 15B; n2 represents the refractive index of the second film layer 152 in the second part 15B; d2 represents the optical thickness of the second film layer 152 in the second part 15B; n3 represents the refractive index of the first film layer 151 in the third part 15C; d3 represents the optical thickness of the first film layer 151 in the third part 15C; n4 represents the refractive index of the second film layer 152 in the third part 15C; d4 represents the optical thickness of the second film layer 152 in the third part 15C; k is an integer.
[0063] Specifically, in this embodiment of the present invention, the first part 15A includes multiple layers of first film 151 and second film 152, and the first part 15A mainly serves as a transition layer; the second part 15B includes multiple layers of first film 151 and second film 152, and the second part 15B mainly achieves the enhancement of blue light transmittance; the third part 15C includes multiple layers of first film 151 and second film 152, and the third part 15C mainly achieves the enhancement of yellow and red light reflectance.
[0064] In an optional embodiment of this utility model, such as Figure 1 As shown, the LED chip provided in this embodiment of the present invention further includes: an insulating layer 16 located on one side of the substrate 11 and covering the epitaxial structure; the insulating layer 16 is located between the epitaxial structure and the optical film layer 15.
[0065] The epitaxial structure provided in this embodiment of the present invention further includes: a first electrode 17 and a second electrode 18; the first electrode 17 is electrically connected to the N-type semiconductor layer 12, and the second electrode 18 is electrically connected to the P-type semiconductor layer 14.
[0066] The LED chip provided in this embodiment of the present invention further includes: a first pad 19, a second pad 20, and a first through hole penetrating the insulating layer 16 and the optical film layer 15; a portion of the first through hole exposes a part of the surface of the first electrode 17, and another portion of the first through hole exposes a part of the surface of the second electrode 18; the first pad 19 is electrically connected to the first electrode 17, and the second pad 20 is electrically connected to the second electrode 18.
[0067] Specifically, in this embodiment of the invention, the insulating layer 16 includes, but is not limited to, a SiO2 layer. The thickness of the insulating layer 16 ranges from 500 angstroms to 10,000 angstroms, for example, the thickness of the insulating layer 16 is 500 angstroms, 900 angstroms, 1200 angstroms, 3450 angstroms, 10,000 angstroms, etc. This insulating layer 16 is the SiO2 surface insulating layer commonly prepared for traditional LED chips, and in the art, this insulating layer 16 is also referred to as a PV layer.
[0068] The technical solution of this application is to add an optical film layer 15 on the basis of the insulating layer 16. By optimizing the periodicity ratio of the optical film layer 15, as well as parameters such as the number of layers and thickness, it can be made to exhibit the effect of enhancing the blue light transmission of the LED chip and enhancing the reflection of the yellow and red light generated by the LED chip, thereby improving the light extraction efficiency of the white light of the LED chip and thus achieving the purpose of improving the light output efficiency of the LED chip.
[0069] In an optional embodiment of this utility model, such as Figure 2 As shown, the LED chip provided in this embodiment of the present invention further includes:
[0070] A first pad 19, a second pad 20, and a second via penetrating the optical film layer 15; a portion of the second via exposes a portion of the surface of the N-type semiconductor layer 12, and another portion of the second via exposes a portion of the surface of the P-type semiconductor layer 14; the first pad 19 is electrically connected to the N-type semiconductor layer 12, and the second pad 20 is electrically connected to the P-type semiconductor layer 14.
[0071] Specifically, in this embodiment of the utility model, the LED chip does not have such... Figure 1 Instead of the insulating layer 16 shown, the optical film layer 15 is formed directly on the surface of the epitaxial structure. That is, the technical solution of this application improves the traditional SiO2 surface insulating layer of the LED chip (which, in this art, is also referred to as the PV layer) by forming alternating stacked first film layers 151 and second film layers 152 with different refractive indices to constitute the optical film layer 15. By optimizing the periodicity ratio of the optical film layer 15, as well as parameters such as the number of film layers and thickness, it can exhibit the effects of enhancing the transmission of blue light generated by the LED chip and enhancing the reflection of yellow and red light generated by the LED chip, thereby improving the light extraction efficiency of white light from the LED chip and achieving the goal of improving the light extraction efficiency of the LED chip; furthermore, the optical film layer 15 also has the effect of surface insulation and passivation.
[0072] In an optional embodiment of this utility model, reference is made to Figure 4 , Figure 4 A schematic diagram of another LED chip provided in an embodiment of the present invention. The LED chip provided in this embodiment of the present invention further includes:
[0073] A buffer layer 21 is located between the substrate 11 and the N-type semiconductor layer 12.
[0074] Specifically, in this embodiment of the invention, the buffer layer 21 is used to buffer defects caused by lattice differences between the epitaxial structure and the substrate 11.
[0075] It should be noted that the surface of the substrate 11 facing the epitaxial structure in the LED chip provided in this embodiment of the present invention can be a roughened surface to improve the light extraction efficiency of the LED chip.
[0076] In an optional embodiment of this utility model, reference is made to Figure 5 , Figure 5 This is a schematic diagram of the structure of another LED chip provided in an embodiment of the present utility model, with reference to... Figure 6 , Figure 6 A schematic diagram of another LED chip provided in an embodiment of the present invention. The LED chip provided in this embodiment of the present invention further includes:
[0077] A transparent conductive layer 22 located on the side of the P-type semiconductor layer 14 facing away from the substrate 11.
[0078] The DBR (Distributed Bragg Reflector) layer 23 is located on the side of the substrate 11 opposite to the N-type semiconductor layer 12.
[0079] Specifically, in this embodiment of the invention, when the LED chip is provided with a transparent conductive layer 22, based on Figure 5 In the LED chip shown, the second electrode 18 is electrically connected to the P-type semiconductor layer 14 through the transparent conductive layer 22; based on Figure 6 In the case of the LED chip shown, the second via actually exposes part of the surface of the transparent conductive layer 22, and the second pad 20 is electrically connected to the P-type semiconductor layer 14 through the transparent conductive layer 22.
[0080] It should be noted that the material of the transparent conductive layer 22 includes, but is not limited to, ITO material. When the material of the transparent conductive layer 22 is ITO material, the transparent conductive layer 22 will also be referred to as an ITO layer in this technical field.
[0081] Among them, the DBR layer 23 is a layered structure formed by alternating and periodically growing two materials with different refractive indices. When the light generated by the LED chip passes through it, it is reflected onto the light-emitting surface, thereby improving the light-emitting efficiency of the LED chip.
[0082] Based on the above embodiments of the present invention, another embodiment of the present invention also provides a lighting device, which includes the LED chip described in the above embodiments.
[0083] The present invention provides a detailed description of an LED chip and lighting device. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.
[0084] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.
[0085] 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.
[0086] The above description of the disclosed embodiments enables those skilled in the art to make or use the present 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 present invention. Therefore, the present 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; An epitaxial structure located on one side of the substrate; the epitaxial structure includes an N-type semiconductor layer, a multiple quantum well layer, and a P-type semiconductor layer stacked sequentially on one side of the substrate; An optical film layer located on one side of the substrate and covering the epitaxial structure; the optical film layer includes a first film layer and a second film layer that are alternately stacked, and the first film layer and the second film layer have different refractive indices; Wherein, the transmittance of the optical film layer to the blue light generated by the LED chip is a first transmittance, the transmittance of the optical film layer to the yellow light generated by the LED chip is a second transmittance, and the transmittance of the optical film layer to the red light generated by the LED chip is a third transmittance; the first transmittance is greater than the second transmittance, and the first transmittance is greater than the third transmittance.
2. The LED chip according to claim 1, characterized in that, The refractive index of the first film layer is less than that of the second film layer.
3. The LED chip according to claim 1, characterized in that, The LED chip further includes: an insulating layer located on one side of the substrate and covering the epitaxial structure; the insulating layer is located between the epitaxial structure and the optical film layer; The epitaxial structure further includes: a first electrode and a second electrode; the first electrode is electrically connected to the N-type semiconductor layer, and the second electrode is electrically connected to the P-type semiconductor layer; The LED chip further includes: a first pad, a second pad, and a first through-hole penetrating the insulating layer and the optical film layer; a portion of the first through-hole exposes a part of the surface of the first electrode, and another portion of the first through-hole exposes a part of the surface of the second electrode; the first pad is electrically connected to the first electrode, and the second pad is electrically connected to the second electrode.
4. The LED chip according to claim 3, characterized in that, The thickness of the insulating layer ranges from 500 angstroms to 10,000 angstroms.
5. The LED chip according to claim 1, characterized in that, The LED chip also includes: A first pad, a second pad, and a second via penetrating the optical film layer; a portion of the second via exposes a portion of the surface of the N-type semiconductor layer, and another portion of the second via exposes a portion of the surface of the P-type semiconductor layer; the first pad is electrically connected to the N-type semiconductor layer, and the second pad is electrically connected to the P-type semiconductor layer.
6. The LED chip according to claim 5, characterized in that, The LED chip also includes: A buffer layer located between the substrate and the N-type semiconductor layer.
7. The LED chip according to any one of claims 1-6, characterized in that, The epitaxial structure further includes: A transparent conductive layer located on the side of the P-type semiconductor layer facing away from the substrate.
8. The LED chip according to any one of claims 1-6, characterized in that, The LED chip also includes: The DBR layer is located on the side of the substrate opposite to the N-type semiconductor layer.
9. The LED chip according to any one of claims 1-6, characterized in that, In a direction away from the epitaxial structure, the optical film layer includes a first portion, a second portion, and a third portion; The optical thickness of the first film layer in the first part is less than 0.1λ1, and the optical thickness of the second film layer in the first part is less than 0.1λ1; The optical thickness of the first film layer in the second part satisfies 2n1d1+k=1 / 2λ1, and the optical thickness of the second film layer in the second part satisfies 2n2d2+k=1 / 2λ1; The optical thickness of the first film layer in the third part satisfies 2n3d3=λ2 / 2, and the optical thickness of the second film layer in the third part satisfies 2n4d4=λ2 / 2; Wherein, λ1 represents the wavelength of light, with a value of 448 nm; λ2 represents the wavelength of light, with a value of 570 nm; n1 represents the refractive index of the first film layer in the second part; d1 represents the optical thickness of the first film layer in the second part; n2 represents the refractive index of the second film layer in the second part; d2 represents the optical thickness of the second film layer in the second part; n3 represents the refractive index of the first film layer in the third part; d3 represents the optical thickness of the first film layer in the third part; n4 represents the refractive index of the second film layer in the third part; d4 represents the optical thickness of the second film layer in the third part; k is an integer.
10. A lighting device, characterized in that, The lighting device includes the LED chip according to any one of claims 1-9.