LED epitaxial structure and LED chip

Abstract

The utility model provides an LED epitaxial structure and an LED chip. A current expansion layer embedded with a metal nano lattice structure is arranged, and the free vibration frequency of the metal nano lattice structure is matched with the photon frequency of emergent light of the epitaxial structure to form a plasmon resonance effect; in a resonance state, the energy of a photon electromagnetic field is effectively converted into collective vibration energy of free electrons, so that resonance electrons on the metal surface are coupled with incident photons, the excited state of a semiconductor is further enhanced, more electron-hole pairs are subjected to radiation recombination, the internal quantum efficiency of the LED epitaxial structure is improved, and meanwhile, the luminous efficiency of the LED epitaxial structure is improved. The interface reflection between different material layers is reduced to increase the light extraction rate; in addition, the current uniformity can be further improved by embedding a metal nano lattice structure in the current expansion layer, so that the luminous efficiency of the device is effectively improved.

Description

Technical Field

[0001] The utility model relates to the field of light emitting diodes, in particular to an LED epitaxial structure and an LED chip. Background Art

[0002] However, with the rapid development of LED technology and the gradual improvement of LED lighting efficiency, the application of LED is becoming more and more extensive, and people are paying more and more attention to the development prospects of LED in display screens. As the core component of LED lamps, the function of LED chips is to convert electrical energy into light energy. Specifically, they include epitaxial wafers and N-type electrodes and P-type electrodes respectively arranged on the epitaxial wafers. The epitaxial wafer includes a P-type semiconductor layer, an N-type semiconductor layer, and an active layer located between the N-type semiconductor layer and the P-type semiconductor layer. When current passes through the LED chip, the holes in the P-type semiconductor and the electrons in the N-type semiconductor will move to the active layer and recombine in the active layer, so that the LED chip emits light.

[0003] At present, in order to achieve current expansion and light extraction inside the LED chip, the design of setting a current expansion layer and a reflector on the surface of the epitaxial structure is usually adopted. For example, in GaN-based LED chips: ITO is usually used as current expansion, but because the refractive index of the ITO transparent conductive layer is 1.9, which is still somewhat different from the refractive index of air, a large part of the light is still reflected back to the substrate and absorbed; at the same time, due to the large body resistance of the ITO transparent conductive layer, the current expansion effect is limited. In AlGaInP-based LED chips: P-GaP window layer is usually used as current expansion and ohmic contact, and a part of the light is reflected to the light-emitting surface through a distributed reflector (DBR reflection structure) or an omnidirectional reflector (ODR reflection structure) to enhance the light output; but the DBR structure only provides high reflectivity for vertically incident and small-angle incident light, and the reflectivity for incident light with a large angle is low, so that the incident light with a large angle will pass through the DBR structure and be absorbed by the substrate; and the ODR structure realized by the reverse polarity process has a strong light extraction rate, but its manufacturing process is complex and the cost is high.

[0004] In view of this, the inventor specially designed an LED epitaxial structure and an LED chip, and this case was thus generated. Utility Model Content

[0005] The utility model aims to provide an LED epitaxial structure and an LED chip to improve the luminous efficiency of the LED chip.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0007] An LED epitaxial structure, comprising:

[0008] substrate;

[0009] An N-type semiconductor layer, an active layer, a P-type semiconductor layer and a current spreading layer stacked in sequence on a surface of one side of the substrate;

[0010] The current spreading layer includes a current spreading layer embedded with a metal nano-lattice structure, and the free vibration frequency of the metal nano-lattice structure matches the frequency of the emitted light photons of the epitaxial structure to form a plasmon resonance effect.

[0011] Preferably, the current spreading layer comprises a first current spreading layer and a second current spreading layer sequentially arranged along the surface of the P-type semiconductor layer; wherein the metal nano-dot lattice structure is arranged on the surface of the first current spreading layer facing away from the P-type semiconductor layer through metal nano-particle intervals, and the second current spreading layer is in contact with the first current spreading layer by being embedded in the metal nano-particle intervals.

[0012] Preferably, a height of the second current spreading layer above the metal nanoparticles is not less than a height of the first current spreading layer.

[0013] Preferably, the height of the first current spreading layer is H 1 , the height of the second current spreading layer above the metal nanoparticle is H 2 , then H 2 ≥1.2*H 1 .

[0014] Preferably, the sizes of the metal nanoparticles are uniform, and adjacent metal nanoparticles are arranged at equal intervals.

[0015] Preferably, the metal nanoparticles include at least one of Ag, Au, Al, Pt, Pd, and Cu. As a preferred solution, the metal nanoparticles are Au, and the surface electron resonance energy thereof is 2.3 eV. According to the wavelength-energy correspondence formula λ=1240 / E, it can be known that the corresponding resonance wavelength reaches about 550 nm at this time, and the plasmon resonance effect can be achieved; as another preferred solution, the metal nanoparticles are Ag, and the surface electron resonance energy thereof is 2.7 eV. According to the wavelength-energy correspondence formula λ=1240 / E, it can be known that the corresponding resonance wavelength is about 450 nm at this time, and the plasmon resonance effect can be achieved.

[0016] Preferably, the metal nanoparticles are circular, elliptical or polygonal in shape.

[0017] In a technical solution of the utility model, the LED epitaxial structure includes an AlGaInP-based LED epitaxial structure; the substrate includes a GaAs substrate, the N-type semiconductor layer includes an N-AlGaInP confinement layer, the active layer includes an MQW multi-quantum well active layer, the P-type semiconductor layer includes a P-AlGaInP confinement layer, and the current spreading layer is a P-GaP window layer;

[0018] The P-GaP window layer includes a first P-GaP window layer and a second P-GaP window layer which are sequentially arranged on the surface of the P-AlGaInP confinement layer; wherein the metal nano-lattice structure is arranged on the surface of the first P-GaP window layer away from the P-AlGaInP confinement layer through metal nano-particle intervals, and the second P-GaP window layer is in contact with the first P-GaP window layer by being embedded in the metal nano-particle intervals.

[0019] Preferably, the thickness of the first P-GaP window layer is 20-100 nm, including the endpoint values; the thickness of the second P-GaP window layer is 50-200 nm, including the endpoint values.

[0020] In another technical solution of the utility model, the LED epitaxial structure includes a GaN-based LED epitaxial structure, the substrate includes a sapphire substrate, the N-type semiconductor layer includes an N-GaN layer, the active layer includes an MQW multi-quantum well active layer, the P-type semiconductor layer includes a P-GaN layer, and the current spreading layer includes an ITO layer;

[0021] The ITO layer includes a first ITO layer and a second ITO layer sequentially arranged on the surface of the P-GaN layer; wherein the metal nanodot lattice structure is arranged on the surface of the first ITO layer facing away from the P-GaN layer through metal nanoparticle intervals, and the second ITO layer is in contact with the first ITO layer by being embedded in the metal nanoparticle intervals.

[0022] Correspondingly, the utility model further provides an LED chip, wherein the LED chip is an AlGaInP-based LED chip, and the LED chip includes the AlGaInP-based LED epitaxial structure in the above technical solution.

[0023] Correspondingly, the utility model further provides an LED chip, wherein the LED chip is a GaN-based LED chip, and the LED chip includes the GaN-based LED epitaxial structure in the above technical solution.

[0024] Through the above technical solution, it can be known that the LED epitaxial structure provided by the utility model includes an N-type semiconductor layer, an active layer, a P-type semiconductor layer and a current expansion layer stacked in sequence on the surface of one side of the substrate; wherein the current expansion layer includes a current expansion layer with an embedded metal nano-dot lattice structure, and the free vibration frequency of the metal nano-dot lattice structure matches the frequency of the output light photons of the epitaxial structure to form a plasmon resonance effect. Based on the above arrangement, when photons are incident on the interface between materials with different refractive indices (such as metal particles, current spreading layer, air, etc.), the free electrons on the metal surface produce collective oscillations due to the effect of the photon electromagnetic field. At this time, the free vibration frequency of the metal nano-lattice structure matches the frequency of the outgoing light photons of the epitaxial structure, thereby forming a plasmon resonance effect. In the resonant state, the energy of the photon electromagnetic field is effectively converted into the collective vibration energy of the free electrons, so that the resonant electrons on the metal surface couple with the incident photons, thereby enhancing the excited state of the semiconductor and causing more electron-hole pairs to radiatively recombine, thereby increasing the internal quantum efficiency of the LED epitaxial structure while reducing the interface reflection between different material layers to increase the light extraction rate. In addition, by embedding a metal nano-lattice structure in the current spreading layer, the current uniformity can be further improved, thereby effectively improving the luminous efficiency of the device.

[0025] Secondly, the current spreading layer includes a first current spreading layer and a second current spreading layer sequentially arranged along the surface of the P-type semiconductor layer; wherein the metal nanostructure is arranged on the surface of the first current spreading layer away from the P-type semiconductor layer through metal nanoparticles, and the second current spreading layer is in contact with the first current spreading layer by embedding the metal nanoparticles at the spacing; further, the height of the second current spreading layer above the metal nanoparticles is not less than the height of the first current spreading layer. Based on this arrangement, the distance between the metal nanolattice structure and the active layer can be shortened while ensuring the uniformity of current spreading, thereby improving the resonant coupling efficiency of photons and metal surface electrons, thereby improving the luminous efficiency of the LED device.

[0026] The utility model also provides an LED chip, which is an AlGaInP-based LED chip, and includes the AlGaInP-based LED epitaxial structure in the above technical solution. By achieving the above beneficial effects at the epitaxial end, the relevant processes for improving the luminous efficiency at the chip design end can be reduced.

[0027] The utility model also provides that the LED chip is a GaN-based LED chip, and the above-mentioned beneficial effects are achieved at the epitaxial end, thereby reducing the relevant processes for improving the luminous efficiency at the chip design end. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0029] Figure 1 A schematic diagram of the structure of an AlGaInP-based LED epitaxial structure provided in Example 1 of the utility model;

[0030] Figure 2 A schematic structural diagram of a GaN-based LED epitaxial structure provided in Example 2 of the utility model;

[0031] Explanation of symbols in the figure:

[0032] 10. GaAs substrate;

[0033] 11. Buffer layer;

[0034] 12. Corrosion cut-off layer;

[0035] 13. Ohmic contact layer;

[0036] 14. N-AlGaInP confinement layer;

[0037] 15. MQW multi-quantum well active layer;

[0038] 16. P-AlGaInP confinement layer;

[0039] 17. The first P-GaP window layer;

[0040] 18. Metal nanolattice structure;

[0041] 19. Second P-GaP window layer;

[0042] 20. Sapphire substrate;

[0043] 21. AlN buffer layer;

[0044] 22. N-GaN layer;

[0045] 23. MQW multi-quantum well active layer;

[0046] 24. P-GaN layer;

[0047] 25. The first ITO layer;

[0048] 26. Metal nanolattice structure;

[0049] 27. Second ITO layer. DETAILED DESCRIPTION

[0050] To make the content of the utility model clearer, the content of the utility model is further described below in conjunction with the accompanying drawings. The utility model is not limited to this specific embodiment. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0051] Example 1

[0052] An LED epitaxial structure, comprising:

[0053] substrate;

[0054] An N-type semiconductor layer, an active layer, a P-type semiconductor layer and a current spreading layer stacked in sequence on a surface of one side of the substrate;

[0055] The current spreading layer includes a current spreading layer embedded with a metal nano-lattice structure, and the free vibration frequency of the metal nano-lattice structure matches the frequency of the emitted light photons of the epitaxial structure to form a plasmon resonance effect.

[0056] Based on the above content, in one embodiment of the present application, the current spreading layer includes a first current spreading layer and a second current spreading layer arranged in sequence along the surface of the P-type semiconductor layer; wherein the metal nanodot lattice structure is arranged on the surface of the first current spreading layer away from the P-type semiconductor layer through metal nanoparticle intervals, and the second current spreading layer forms contact with the first current spreading layer by being embedded in the metal nanoparticle intervals.

[0057] Based on the above, in one embodiment of the present application, the height of the second current spreading layer above the metal nanoparticles is not less than the height of the first current spreading layer.

[0058] Based on the above, in one embodiment of the present application, the height of the first current spreading layer is H 1 , the height of the second current spreading layer above the metal nanoparticle is H 2 , then H 2 ≥1.2*H 1 .

[0059] Based on the above content, in one embodiment of the present application, the size of each of the metal nanoparticles is uniform, and each adjacent metal nanoparticle is arranged at equal intervals.

[0060] Based on the above, in one embodiment of the present application, the metal nanoparticles include at least one of Ag, Au, Al, Pt, Pd, and Cu. As a preferred embodiment, the metal nanoparticles are Au, and the surface electron resonance energy thereof is 2.3 eV. According to the wavelength and energy corresponding relationship λ=1240 / E, it can be known that the corresponding resonance wavelength reaches about 550 nm at this time, and the plasmon resonance effect can be achieved; as another preferred embodiment, the metal nanoparticles are Ag, and the surface electron resonance energy thereof is 2.7 eV. According to the wavelength and energy corresponding relationship λ=1240 / E, it can be known that the corresponding resonance wavelength is about 450 nm at this time, and the plasmon resonance effect can be achieved.

[0061] Based on the above content, in one embodiment of the present application, the metal nanoparticles are circular, elliptical or polygonal.

[0062] This embodiment also provides a method for manufacturing an LED epitaxial structure, the manufacturing method comprising:

[0063] providing a substrate;

[0064] Epitaxially growing an N-type semiconductor layer, an active layer, a P-type semiconductor layer and a first current spreading layer in sequence on the surface of the substrate;

[0065] A metal thin film is deposited on the surface of the first current spreading layer by physical vapor deposition, and a photolithography process is performed to form a metal nano dot lattice structure, wherein the metal nano dot lattice structure is arranged on the surface of the first current spreading layer away from the P-type semiconductor layer through metal nanoparticles.

[0066] A second current spreading layer is grown by secondary epitaxial growth, and the second current spreading layer is in contact with the first current spreading layer by being embedded in the intervals between the metal nanoparticles.

[0067] Specifically, Figure 1As shown, in one embodiment of the present application, the LED epitaxial structure includes an AlGaInP-based LED epitaxial structure; the substrate includes a GaAs substrate 10, the N-type semiconductor layer includes an N-AlGaInP confinement layer 14, the active layer includes an MQW multi-quantum well active layer 15, the P-type semiconductor layer includes a P-AlGaInP confinement layer 16, and the current spreading layer is a P-GaP window layer; further, a buffer layer (as a preferred solution, the buffer layer includes an N-GaAs buffer layer 11), a corrosion stop layer (as a preferred solution, the corrosion stop layer includes an N-GaInP corrosion stop layer 12), and an ohmic contact layer (as a preferred solution, the ohmic contact layer includes an N-GaAs ohmic contact layer 13) may be sequentially provided between the GaAs substrate and the N-AlGaInP confinement layer, but the present application does not limit this.

[0068] The P-GaP window layer includes a first P-GaP window layer 17 and a second P-GaP window layer 19 which are sequentially arranged on the surface of the P-AlGaInP restriction layer; wherein the metal nano-lattice structure 18 is arranged on the surface of the first P-GaP window layer 17 which is away from the P-AlGaInP restriction layer 16 through metal nano-particle intervals, and the second P-GaP window layer 19 is in contact with the first P-GaP window layer 17 by being embedded in the metal nano-particle intervals.

[0069] Furthermore, the thickness of the first P-GaP window layer is 20-100 nm, including the endpoint values; the thickness of the second P-GaP window layer is 50-200 nm, including the endpoint values.

[0070] Correspondingly, the utility model further provides an LED chip, wherein the LED chip is an AlGaInP-based LED chip, and the LED chip includes the AlGaInP-based LED epitaxial structure in the above technical solution.

[0071] Through the above technical solution, it can be known that the LED epitaxial structure provided in this embodiment includes an N-type semiconductor layer, an active layer, a P-type semiconductor layer and a current expansion layer stacked in sequence on the surface of one side of the substrate; wherein the current expansion layer includes a current expansion layer with an embedded metal nano-dot lattice structure, and the free vibration frequency of the metal nano-dot lattice structure matches the frequency of the output light photons of the epitaxial structure to form a plasmon resonance effect. Based on the above arrangement, when photons are incident on the interface between materials with different refractive indices (such as metal particles, current spreading layer, air, etc.), the free electrons on the metal surface produce collective oscillations due to the effect of the photon electromagnetic field. At this time, the free vibration frequency of the metal nano-lattice structure matches the frequency of the outgoing light photons of the epitaxial structure, thereby forming a plasmon resonance effect. In the resonant state, the energy of the photon electromagnetic field is effectively converted into the collective vibration energy of the free electrons, so that the resonant electrons on the metal surface couple with the incident photons, thereby enhancing the excited state of the semiconductor and causing more electron-hole pairs to radiatively recombine, thereby increasing the internal quantum efficiency of the LED epitaxial structure while reducing the interface reflection between different material layers to increase the light extraction rate. In addition, by embedding a metal nano-lattice structure in the current spreading layer, the current uniformity can be further improved, thereby effectively improving the luminous efficiency of the device.

[0072] Secondly, the current spreading layer includes a first current spreading layer and a second current spreading layer sequentially arranged along the surface of the P-type semiconductor layer; wherein the metal nanostructure is arranged on the surface of the first current spreading layer away from the P-type semiconductor layer through metal nanoparticles, and the second current spreading layer is in contact with the first current spreading layer by embedding the metal nanoparticles at the spacing; further, the height of the second current spreading layer above the metal nanoparticles is not less than the height of the first current spreading layer. Based on this arrangement, the distance between the metal nanolattice structure and the active layer can be shortened while ensuring the uniformity of current spreading, thereby improving the resonant coupling efficiency of photons and metal surface electrons, thereby improving the luminous efficiency of the LED device.

[0073] This embodiment also provides a method for manufacturing an LED epitaxial structure, which, while achieving the above-mentioned beneficial effects, has a simple manufacturing process and is conducive to productization.

[0074] This embodiment also provides an LED chip, which is an AlGaInP-based LED chip, and includes the AlGaInP-based LED epitaxial structure in the above technical solution. By achieving the above beneficial effects at the epitaxial end, the relevant processes for improving the luminous efficiency at the chip design end can be reduced.

[0075] Example 2

[0076] An LED epitaxial structure, comprising:

[0077] substrate;

[0078] An N-type semiconductor layer, an active layer, a P-type semiconductor layer and a current spreading layer stacked in sequence on a surface of one side of the substrate;

[0079] The current spreading layer includes a current spreading layer embedded with a metal nano-lattice structure, and the free vibration frequency of the metal nano-lattice structure matches the frequency of the emitted light photons of the epitaxial structure to form a plasmon resonance effect.

[0080] Based on the above content, in one embodiment of the present application, the current spreading layer includes a first current spreading layer and a second current spreading layer arranged in sequence along the surface of the P-type semiconductor layer; wherein the metal nanodot lattice structure is arranged on the surface of the first current spreading layer away from the P-type semiconductor layer through metal nanoparticle intervals, and the second current spreading layer forms contact with the first current spreading layer by being embedded in the metal nanoparticle intervals.

[0081] Based on the above, in one embodiment of the present application, the height of the second current spreading layer above the metal nanoparticles is not less than the height of the first current spreading layer.

[0082] Based on the above, in one embodiment of the present application, the height of the first current spreading layer is H 1 , the height of the second current spreading layer above the metal nanoparticle is H 2 , then H 2 ≥1.2*H 1 .

[0083] Based on the above content, in one embodiment of the present application, the size of each of the metal nanoparticles is uniform, and each adjacent metal nanoparticle is arranged at equal intervals.

[0084] Based on the above, in one embodiment of the present application, the metal nanoparticles include at least one of Ag, Au, Al, Pt, Pd, and Cu. As a preferred embodiment, the metal nanoparticles are Au, and the surface electron resonance energy thereof is 2.3 eV. According to the wavelength and energy corresponding relationship λ=1240 / E, it can be known that the corresponding resonance wavelength reaches about 550 nm at this time, and the plasmon resonance effect can be achieved; as another preferred embodiment, the metal nanoparticles are Ag, and the surface electron resonance energy thereof is 2.7 eV. According to the wavelength and energy corresponding relationship λ=1240 / E, it can be known that the corresponding resonance wavelength is about 450 nm at this time, and the plasmon resonance effect can be achieved.

[0085] Based on the above content, in one embodiment of the present application, the metal nanoparticles are circular, elliptical or polygonal.

[0086] This embodiment also provides a method for manufacturing an LED epitaxial structure, the manufacturing method comprising:

[0087] providing a substrate;

[0088] Epitaxially growing an N-type semiconductor layer, an active layer, a P-type semiconductor layer and a first current spreading layer in sequence on the surface of the substrate;

[0089] A metal thin film is deposited on the surface of the first current spreading layer by physical vapor deposition, and a photolithography process is performed to form a metal nano dot lattice structure, wherein the metal nano dot lattice structure is arranged on the surface of the first current spreading layer away from the P-type semiconductor layer through metal nanoparticles.

[0090] A second current spreading layer is grown by secondary epitaxial growth, and the second current spreading layer is in contact with the first current spreading layer by being embedded in the intervals between the metal nanoparticles.

[0091] Specifically, Figure 2 As shown, in one embodiment of the present application, the LED epitaxial structure includes a GaN-based LED epitaxial structure, the substrate includes a sapphire substrate 20, the N-type semiconductor layer includes an N-GaN layer 22, the active layer includes an MQW multi-quantum well active layer 23, the P-type semiconductor layer includes a P-GaN layer 24, and the current spreading layer includes an ITO layer; further, a buffer layer may be provided between the sapphire substrate and the N-GaN layer (as a preferred solution, the buffer layer includes an AlN buffer layer 21), but the present application does not limit this;

[0092] The ITO layer includes a first ITO layer 25 and a second ITO layer sequentially arranged on the surface of the P-GaN layer; wherein the metal nanodot lattice structure 26 is arranged on the surface of the first ITO layer 25 away from the P-GaN layer 24 through metal nanoparticle intervals, and the second ITO layer 27 forms contact with the first ITO layer 25 by being embedded in the metal nanoparticle intervals.

[0093] Furthermore, the thickness of the first ITO layer is 20-100 nm, including the endpoint values; the thickness of the second ITO layer is 50-200 nm, including the endpoint values.

[0094] Correspondingly, the utility model further provides an LED chip, wherein the LED chip is a GaN-based LED chip, and the LED chip includes the GaN-based LED epitaxial structure in the above technical solution.

[0095] Through the above technical solution, it can be known that the LED epitaxial structure provided in this embodiment includes an N-type semiconductor layer, an active layer, a P-type semiconductor layer and a current expansion layer stacked in sequence on the surface of one side of the substrate; wherein the current expansion layer includes a current expansion layer with an embedded metal nano-dot lattice structure, and the free vibration frequency of the metal nano-dot lattice structure matches the frequency of the output light photons of the epitaxial structure to form a plasmon resonance effect. Based on the above arrangement, when photons are incident on the interface between materials with different refractive indices (such as metal particles, current spreading layer, air, etc.), the free electrons on the metal surface produce collective oscillations due to the effect of the photon electromagnetic field. At this time, the free vibration frequency of the metal nano-lattice structure matches the frequency of the outgoing light photons of the epitaxial structure, thereby forming a plasmon resonance effect. In the resonant state, the energy of the photon electromagnetic field is effectively converted into the collective vibration energy of the free electrons, so that the resonant electrons on the metal surface couple with the incident photons, thereby enhancing the excited state of the semiconductor and causing more electron-hole pairs to radiatively recombine, thereby increasing the internal quantum efficiency of the LED epitaxial structure while reducing the interface reflection between different material layers to increase the light extraction rate. In addition, by embedding a metal nano-lattice structure in the current spreading layer, the current uniformity can be further improved, thereby effectively improving the luminous efficiency of the device.

[0096] Secondly, the current spreading layer includes a first current spreading layer and a second current spreading layer sequentially arranged along the surface of the P-type semiconductor layer; wherein the metal nanostructure is arranged on the surface of the first current spreading layer away from the P-type semiconductor layer through metal nanoparticles, and the second current spreading layer is in contact with the first current spreading layer by embedding the metal nanoparticles at the spacing; further, the height of the second current spreading layer above the metal nanoparticles is not less than the height of the first current spreading layer. Based on this arrangement, the distance between the metal nanolattice structure and the active layer can be shortened while ensuring the uniformity of current spreading, thereby improving the resonant coupling efficiency of photons and metal surface electrons, thereby improving the luminous efficiency of the LED device.

[0097] This embodiment also provides a method for manufacturing an LED epitaxial structure, which, while achieving the above-mentioned beneficial effects, has a simple manufacturing process and is conducive to productization.

[0098] This embodiment also provides that the LED chip is a GaN-based LED chip, and by achieving the above-mentioned beneficial effects at the epitaxial end, the relevant processes for improving the luminous efficiency at the chip design end can be reduced.

[0099] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0100] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or device. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the article or device including the above elements.

[0101] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be 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 application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An LED epitaxial structure, characterized in that: include: substrate; An N-type semiconductor layer, an active layer, a P-type semiconductor layer and a current spreading layer stacked in sequence on a surface of one side of the substrate; The current spreading layer includes a current spreading layer embedded with a metal nano-lattice structure, and the free vibration frequency of the metal nano-lattice structure matches the frequency of the emitted light photons of the epitaxial structure to form a plasmon resonance effect.

2. The LED epitaxial structure according to claim 1, characterized in that: The current spreading layer includes a first current spreading layer and a second current spreading layer sequentially arranged along the surface of the P-type semiconductor layer; wherein the metal nanodot lattice structure is arranged on the surface of the first current spreading layer away from the P-type semiconductor layer through metal nanoparticle intervals, and the second current spreading layer is in contact with the first current spreading layer by being embedded in the metal nanoparticle intervals.

3. The LED epitaxial structure according to claim 2, characterized in that: A height of the second current spreading layer above the metal nanoparticle is not less than a height of the first current spreading layer.

4. The LED epitaxial structure according to claim 3, characterized in that: The height of the first current spreading layer is H1, and the height of the second current spreading layer above the metal nanoparticle is H2, then H2≥1.2*H1.

5. The LED epitaxial structure according to claim 2, characterized in that: The sizes of the metal nanoparticles are uniform, and adjacent metal nanoparticles are arranged at equal intervals.

6. The LED epitaxial structure according to claim 2, characterized in that: The metal nanoparticles include at least one of Ag, Au, Al, Pt, Pd, and Cu.

7. The LED epitaxial structure according to claim 2, characterized in that: The metal nanoparticles are circular, elliptical or polygonal in shape.

8. The LED epitaxial structure according to any one of claims 1 to 7, characterized in that: The LED epitaxial structure includes an AlGaInP-based LED epitaxial structure; the substrate includes a GaAs substrate, the N-type semiconductor layer includes an N-AlGaInP confinement layer, the active layer includes an MQW multi-quantum well active layer, the P-type semiconductor layer includes a P-AlGaInP confinement layer, and the current spreading layer is a P-GaP window layer; The P-GaP window layer includes a first P-GaP window layer and a second P-GaP window layer which are sequentially arranged on the surface of the P-AlGaInP confinement layer; wherein the metal nano-lattice structure is arranged on the surface of the first P-GaP window layer away from the P-AlGaInP confinement layer through metal nano-particle intervals, and the second P-GaP window layer is in contact with the first P-GaP window layer by being embedded in the metal nano-particle intervals.

9. The LED epitaxial structure according to claim 8, characterized in that: The thickness of the first P-GaP window layer is 20-100 nm, including the endpoint values; the thickness of the second P-GaP window layer is 50-200 nm, including the endpoint values.

10. The LED epitaxial structure according to any one of claims 1 to 7, characterized in that: The LED epitaxial structure includes a GaN-based LED epitaxial structure, the substrate includes a sapphire substrate, the N-type semiconductor layer includes an N-GaN layer, the active layer includes an MQW multi-quantum well active layer, the P-type semiconductor layer includes a P-GaN layer, and the current spreading layer includes an ITO layer; The ITO layer includes a first ITO layer and a second ITO layer sequentially arranged on the surface of the P-GaN layer; wherein the metal nanodot lattice structure is arranged on the surface of the first ITO layer facing away from the P-GaN layer through metal nanoparticle intervals, and the second ITO layer is in contact with the first ITO layer by being embedded in the metal nanoparticle intervals.

11. An LED chip, the LED chip is an AlGaInP-based LED chip, characterized in that: It comprises the AlGaInP-based LED epitaxial structure as claimed in claim 8.

12. An LED chip, wherein the LED chip is a GaN-based LED chip, characterized in that: It comprises the GaN-based LED epitaxial structure as claimed in claim 10.

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