Deep ultraviolet led device with photo-induced hole compensation structure and method of manufacturing the same

Abstract

This invention discloses a deep ultraviolet LED device with a photoinduced hole compensation structure and its fabrication method. The LED device, from bottom to top, comprises: a substrate, a buffer layer, an electron transport layer, an active region, an electron blocking layer, a hole injection layer, an ohmic contact layer, an n-type light absorption layer, an insulating layer, a p-type ohmic electrode, an n-type ohmic electrode, and a mirror electrode. The electron transport layer is partially exposed, and the upper surface of the exposed portion is covered with an n-type ohmic electrode. At least one groove is etched in the hole injection layer, and an n-type light absorption layer is deposited in the groove. P-type ohmic electrodes are covered on the hole injection layer and the n-type light absorption layer. This invention facilitates vertical / quasi-vertical hole injection into the active region, increasing the hole concentration in the active region. Holes can be horizontally injected into the metal-semiconductor interface, increasing the hole concentration on the surface of the p-type semiconductor layer, reducing the interface barrier, effectively suppressing phonon generation during the photon-hole conversion process, lowering the device junction temperature, and improving the device's thermal stability.

Description

Technical Field

[0001] This invention relates to the field of semiconductor optoelectronics, and more specifically, to a deep ultraviolet LED device with a photoinduced hole compensation structure and its fabrication method. Background Technology

[0002] Deep ultraviolet (DUV) LEDs are solid-state light sources emitting wavelengths in the 200-280 nm range. Compared to traditional mercury lamps, DUV LEDs offer advantages such as smaller size, longer lifespan, lower energy consumption, and mercury-free operation, making them promising for applications in disinfection, environmental monitoring, and ultraviolet communication. However, the current luminous efficiency and electro-optical conversion efficiency of DUV LEDs still cannot meet practical application requirements. The low luminous efficiency and electro-optical conversion efficiency of DUV LEDs are mainly due to factors such as low carrier injection efficiency, severe photon self-absorption effects, and severe hole depletion at the metal-semiconductor interface.

[0003] To address the aforementioned issues, patent CN 113594311 A designed a hole compensation layer for the P-type semiconductor layer. This ensured a high hole concentration in the P-type semiconductor layer while reducing the absorption of deep ultraviolet light by the internal structure of the deep ultraviolet LED chip. Patent CN 112885933 A designed patterned bumps or pits on the surface of the N-type semiconductor transport layer. This increased the contact area between the N electrode and the N-AlGaN layer, reducing contact resistance. Furthermore, it improved light scattering on the N-AlGaN layer surface, breaking the optical waveguide effect of the N-AlGaN layer, thereby improving the bottom light extraction efficiency and light extraction efficiency of the device, ultimately enhancing the photoelectric conversion efficiency. However, it is currently difficult to further improve the light extraction efficiency of deep ultraviolet LEDs, especially in small-sized, short-wavelength deep ultraviolet LEDs, where over 90% of photons still cannot escape and are ultimately absorbed by the material and converted into phonons. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of low luminous efficiency and electro-optical conversion efficiency caused by poor hole injection efficiency, severe photon self-absorption, and severe hole depletion at the metal-semiconductor interface in existing deep ultraviolet LEDs.

[0005] To achieve the above objectives, the first aspect of the present invention provides a deep ultraviolet LED device with a photoinduced hole compensation structure, wherein the deep ultraviolet LED device comprises, from bottom to top: a substrate, a buffer layer, an electron transport layer, an active region, an electron blocking layer, a hole injection layer, an n-type light absorption layer, an insulating layer, a p-type ohmic electrode, an n-type ohmic electrode, and a reflector electrode;

[0006] The electron transport layer is partially exposed, and the upper surface of the exposed portion of the electron transport layer is covered with an n-type ohmic electrode. At least one groove is etched in the hole injection layer, and an n-type light absorption layer is deposited in the groove. The hole injection layer and the n-type light absorption layer are covered with p-type ohmic electrodes.

[0007] Preferably, the overall shape of the device includes triangles, circles, rectangles, and annulus.

[0008] Preferably, the etching depth of each groove is 10 nm-100 nm, the etching width is 5 μm-100 μm, and the area of ​​the groove portion accounts for 10% to 80% of the total area of ​​the hole injection layer and the ohmic contact layer.

[0009] Preferably, the substrate is made of at least one of sapphire, SiC, Si, AlN, GaN or quartz glass; the substrate is classified as a polar surface substrate, a semi-polar surface substrate or a non-polar surface substrate according to the different epitaxial growth directions.

[0010] Preferably, the buffer layer is made of AlGaN or AlN and has a thickness of 500 nm to 2 μm.

[0011] Preferably, the electron transport layer is made of Al. x1 Ga 1-x1 N, where 0≤x1≤1, 0≤1-x1≤1, has a thickness of 1 μm~4 μm, and the exposed portion of the electron transport layer accounts for 5%-80% of the entire electron transport layer.

[0012] Preferably, the active region comprises several layers of quantum barriers and quantum wells, wherein the quantum barriers are made of Al. x2 Ga 1-x2 N, 0≤x²≤1, 0≤1-x²≤1; the quantum well is made of Al. x3 Ga 1-x3 N, 0≤x3≤1, 0≤1-x3≤1 and x3≤x2; the thickness of the active region is 10 nm~300 nm.

[0013] Preferably, the electron blocking layer is made of Al. x4 Ga 1-x4 N, where 0 ≤ x4 ≤ 1, 0 ≤ 1 - x4 ≤ 1 and x2 ≤ x4; the thickness is 10 nm to 40 nm.

[0014] The hole injection layer is made of Al. x5 Ga 1-x5 N, where 0 ≤ x5 ≤ 1, 0 ≤ 1 - x5 ≤ 1; thickness is 10 nm ~ 100 nm;

[0015] The material of the n-type light absorption layer is BN, Ga2O3, ZnO, GaN or AlGaN, and its thickness is 10 nm to 100 nm.

[0016] The insulating layer material is SiO2, HfO2 or Al2O3, and its thickness is 20 nm to 1 μm.

[0017] Preferably, the material of the p-type ohmic electrode is Ni / Au, Ni / Al, Cr / Au, or Pt / Au; the material of the n-type ohmic electrode is Cr / Al, Al / Au, Cr / Au, or Ti / Al / Ti / Au; and the material of the mirror electrode is Al / Ti / Au or Ti / Al / Ti / Au.

[0018] To achieve the objective of this invention, a second aspect provides a method for fabricating a deep ultraviolet LED device with a photoinduced hole compensation structure, used to fabricate the deep ultraviolet LED device with a photoinduced hole compensation structure described in the above technical solution. The fabrication method includes the following steps:

[0019] S1. First, the substrate is baked at 950℃~1350℃ in an MOCVD reactor to remove foreign matter from the substrate surface. Then, a buffer layer, an electron transport layer, an active region, an electron blocking layer, a hole injection layer, and an ohmic contact layer are grown respectively.

[0020] S2, on the product obtained in S1, exposes the electron transport layer through photolithography and deep etching, and etches the surface;

[0021] S3, on the mesa obtained in S2, grooves are etched in the hole injection layer and the ohmic contact layer by photolithography and dry etching processes;

[0022] S4, based on S3, uses MOCVD or magnetron sputtering technology to grow an n-type light-absorbing layer material in the groove;

[0023] S5, based on S4, uses photolithography and electron beam evaporation technology to fabricate the n-type ohmic electrode and p-type ohmic electrode of LED;

[0024] S6, based on S5, uses PECVD or ALD technology to grow an insulating layer with a thickness of 20 nm-1 μm;

[0025] S7, based on S6, uses photolithography and wet etching techniques to remove the insulating layer covering the n-type ohmic electrode and the p-type ohmic electrode;

[0026] S8, based on S7, uses photolithography and electron beam evaporation technology to fabricate the reflective electrode of the LED.

[0027] Compared with the prior art, the beneficial effects of this invention are:

[0028] The device structure of this invention embeds an n-type light-absorbing layer into a p-type hole injection layer, increasing the lateral transport path of holes, reducing hole depletion at the metal-semiconductor interface, alleviating current crowding effects, and reducing the generation of local Joule heating. Under forward voltage, the p-type electron blocking layer and the embedded n-type light-absorbing layer can improve the vertical injection efficiency of charge carriers and reduce the possibility of electron leakage into the p-region, thereby reducing the self-heating effect caused by non-radiative recombination and improving the luminous efficiency of deep ultraviolet LED devices. The embedding of the n-type light-absorbing layer realizes photon-hole conversion, solving the serious problem of photon self-absorption effect, thereby improving photoelectric conversion efficiency. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the initial epitaxial layer structure in the embodiments of this application.

[0030] Figure 2 This is a schematic diagram illustrating the fabrication of a mesa using photolithography and etching processes to expose the electron transport layer, as described in an embodiment of this application.

[0031] Figure 3 This is a schematic diagram illustrating the fabrication of patterned grooves in the hole injection layer using photolithography and dry etching, as described in an embodiment of this application.

[0032] Figure 4 This is a schematic diagram of growing an n-type light-absorbing layer in a groove using MOCVD or magnetron sputtering technology, as described in an embodiment of this application.

[0033] Figure 5 This is a schematic diagram of the growth of an n-type ohmic electrode using photolithography and electron beam evaporation techniques according to an embodiment of this application.

[0034] Figure 6 This is a schematic diagram of the growth of a p-type ohmic electrode using photolithography and electron beam evaporation techniques according to an embodiment of this application.

[0035] Figure 7 This is a schematic diagram of the growth of an insulating layer using photolithography, wet etching, and PECVD techniques in an embodiment of this application.

[0036] Figure 8 This is a schematic diagram of the growth of mirror electrodes using photolithography and electron beam evaporation techniques according to an embodiment of this application.

[0037] Figure 9 The diagram illustrates the relationship between optical power and current for the device according to the embodiments of this application and conventional devices.

[0038] In the figure, 1. Substrate, 2. Buffer layer, 3. Electron transport layer, 4. Active region, 5. Electron blocking layer, 6. Hole injection layer, 7. n-type light absorption layer, 8. n-type ohmic electrode, 9. p-type ohmic electrode, 10. Insulating layer, 11. Mirror electrode. Detailed Implementation

[0039] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0040] In the description of this invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0041] Example 1

[0042] This embodiment 1 provides a deep ultraviolet LED device with a photoinduced hole compensation structure, such as Figure 1 The structure shown is a schematic diagram of an epitaxial wafer structure of a deep ultraviolet LED device with a photoinduced hole compensation structure fabricated on substrate 101 using epitaxial technology. The structure includes: substrate (1), buffer layer (2), electron transport layer (3), active region (4), electron blocking layer (5), and hole injection layer (6).

[0043] Figure 2 The structure shown indicates that the epitaxial wafer structure that exposes the electron transport layer (3) by photolithography and deep etching includes, along the epitaxial growth direction, the following components in sequence: substrate (1), buffer layer (2), electron transport layer (3), active region (4), electron blocking layer (5), and hole injection layer (6).

[0044] Figure 3 The structure shown indicates that the epitaxial wafer structure with grooves etched in the hole injection layer (6) by photolithography and dry etching includes, along the epitaxial growth direction, the following components in sequence: substrate (1), buffer layer (2), electron transport layer (3), active region (4), electron blocking layer (5), and hole injection layer (6).

[0045] Figure 4The structure shown indicates that the epitaxial wafer structure in which an n-type light absorption layer is grown in a groove by MOCVD includes, along the epitaxial growth direction, the following components in sequence: substrate (1), buffer layer (2), electron transport layer (3), active region (4), electron blocking layer (5), hole injection layer (6), and n-type light absorption layer (7).

[0046] Figure 5 The structure shown indicates that an n-type ohmic electrode (8) is deposited on the exposed electron transport layer (3) by photolithography and electron beam evaporation.

[0047] Figure 6 The structure shown indicates that a p-type ohmic electrode (9) is deposited on the surface of the hole injection layer (6) and the n-type light absorption layer (7) by photolithography and electron beam evaporation.

[0048] Figure 7 The structure shown indicates that an insulating layer (10) is grown on the exposed upper surface of the electron transport layer, the active region, the electron blocking layer, and the side of the hole injection layer by photolithography and ALD or PECVD techniques.

[0049] Figure 8 The structure shown indicates that a mirror electrode (11) is deposited on the surface of the n-type ohmic contact electrode (8) and the p-type ohmic contact electrode (9) by photolithography and electron beam evaporation.

[0050] Figure 8 The structure shown illustrates a deep ultraviolet LED device with a photoinduced hole compensation structure. The deep ultraviolet LED device comprises, along the epitaxial direction, a substrate, a buffer layer, and an electron transport layer; the electron transport layer is made of n-Al. x Ga 1-x N is divided into upper and lower layers. The area of ​​the upper layer is 50% to 90% of the area of ​​the lower layer, and the thickness of the upper layer is 10% to 50% of the total layer thickness. n-Al x Ga 1-x The upper surface of the lower N-electron transport layer is covered with an n-type ohmic electrode, the area of ​​which is n-Al. x Ga 1- x The electron transport layer comprises 5% to 90% of the n-type electron layer, and the n-type ohmic electrode is made of Cr / Al, Al / Au, Cr / Au, or Ti / Al / Ti / Au material; nA lx Ga 1-xAbove the N-electron transport layer, an active region, an electron blocking layer, and a hole injection layer are sequentially coated. A groove is etched in the hole injection layer, and an n-type light-absorbing layer is grown in the groove using metal-organic chemical vapor deposition (MOCVD). A p-type ohmic electrode is then coated on the n-type light-absorbing layer and the hole injection layer, with a coverage area of ​​10%–100%. The p-type ohmic electrode is made of Ni / Au, Ni / Al, Cr / Au, or Pt / Au. In the n-Al... x Ga 1-x An insulating layer covers the exposed upper surface of the N-type electron transport layer, the active region, the electron blocking layer, and the sidewalls of the hole injection layer to prevent electron leakage. Reflective electrodes, made of Al / Ti / Au or Ti / Al / Ti / Au, are covered on the n-type ohmic electrode and the p-type ohmic electrode.

[0051] In this embodiment 1, a deep ultraviolet LED device with a photoinduced hole compensation structure is described. The deep ultraviolet LED device includes, along the epitaxial growth direction, a substrate (1), a buffer layer (2), and an electron transport layer (3). The electron transport layer is divided into two parts: the lower layer completely covers the buffer layer (2) and has a thickness of 3 μm; the upper layer has a projected area of ​​25% of the area of ​​the lower layer and a thickness of 1 μm. The upper layer of the electron transport layer (3) consists of an active region (4), an electron blocking layer (5), and a hole transport layer (6). The substrate (1) is sapphire; the buffer layer (2) is AlN; and the electron transport layer (3) is made of n-Al. x1 Ga 1-x1 The N and Al composition is 0.82; the active region (4) includes a quantum barrier and a quantum well, and the quantum barrier is made of Al. x2 Ga 1-x2 The N, Al composition is 0.80, and the thickness is 9 nm; the quantum well material is Al. x3 Ga 1-x3 The N,Al composition is 0.60, the number of quantum wells is 3, and the thickness is 1 nm; the electron blocking layer (5) is Al x4 Ga 1-x4 The N-component graded layer has an Al component that gradually changes from 0.82 to 0.67 and has a thickness of 40 nm; the hole injection layer (6) is a P-Al layer. x5 Ga 1-x5 An N-component graded layer, wherein the Al composition is graded from 0.67 to 0.00, with a thickness of 10 nm; firstly, a surface is etched on the epitaxial wafer using photolithography and deep etching techniques, and then an Al layer is applied... x5 Ga 1-x5 Three grooves, each 20 μm wide and 10 nm deep, were etched in the middle of an N-component gradient hole injection layer using photolithography and dry etching techniques. Then, n-type ZnO was grown and filled into the grooves using MOCVD. Electrodes were grown on the n-Al layer using photolithography and electron beam evaporation techniques. x1 Ga1-x1 An n-type ohmic electrode is grown on the surface of the N-electron transport layer. The n-type ohmic electrode is made of Ti / Al / Ti / Au (20 / 30 / 50 / 100 nm). A p-type ohmic electrode is grown on the surface of the hole injection layer and the n-type ZnO layer. The p-type ohmic electrode is made of Ni / Au (10 / 10 nm). Then, a passivation layer of SiO2 with a thickness of 300 nm is grown using photolithography and PECVD. Next, the SiO2 on the n-type and p-type ohmic electrodes is etched using photolithography and BOE solution. Finally, a mirror electrode made of Al / Ti / Au is deposited on the n-type and p-type ohmic electrodes using photolithography and electron beam evaporation. The overall device size is 100 μm × 100 μm.

[0052] Example 2

[0053] This embodiment 2 provides a method for fabricating a deep ultraviolet LED device with a photoinduced hole compensation structure, used to fabricate the deep ultraviolet LED device with a photoinduced hole compensation structure described in embodiment 1. The fabrication method includes the following steps:

[0054] S1. First, the substrate is baked at 950℃~1350℃ in an MOCVD reactor to remove foreign matter from the substrate surface. Then, a buffer layer, an electron transport layer, an active region, an electron blocking layer, a hole injection layer, and an ohmic contact layer are grown respectively.

[0055] S2, on the product obtained in S1, exposes the electron transport layer through photolithography and deep etching, and etches the surface;

[0056] S3, on the mesa obtained in S2, grooves are etched in the hole injection layer and the ohmic contact layer by photolithography and dry etching processes;

[0057] S4, based on S3, uses MOCVD or magnetron sputtering technology to grow an n-type light-absorbing layer material in the groove;

[0058] S5, based on S4, uses photolithography and electron beam evaporation technology to fabricate the n-type ohmic electrode and p-type ohmic electrode of LED;

[0059] S6, based on S5, uses PECVD or ALD technology to grow an insulating layer with a thickness of 20 nm-1 μm;

[0060] S7, based on S6, uses photolithography and wet etching techniques to remove the insulating layer covering the n-type ohmic electrode and the p-type ohmic electrode;

[0061] S8, based on S7, uses photolithography and electron beam evaporation technology to fabricate the reflective electrode of the LED.

[0062] Example 3

[0063] The deep ultraviolet LED device with a photoinduced hole compensation structure in this embodiment 3 differs from that in embodiment 1 in that the etching depth of the groove is changed from 10 nm to 50 nm or 100 nm.

[0064] Figure 9 The curves showing the relationship between the optical power of the device of this invention and that of a conventional device as a function of current are shown below. Figure 9 It is known that the deep ultraviolet LED device with photoinduced hole compensation structure of the present invention increases its optical power at a faster rate as the current increases.

[0065] In summary, the present invention designs a deep ultraviolet LED device structure with a photoinduced hole compensation structure. On the one hand, holes can be injected vertically / quasi-vertically into the active region, increasing the hole concentration in the active region. On the other hand, through the novel device structure design, holes can be injected horizontally into the metal-semiconductor interface, increasing the hole concentration on the surface of the p-type semiconductor layer and reducing the interface barrier. Simultaneously, the photon-hole conversion process can effectively suppress phonon generation, reduce the device junction temperature, and improve the device's thermal stability. The device structure of the present invention embeds an n-type light-absorbing layer into a p-type hole injection layer, increasing the lateral transport path of holes, reducing hole depletion at the metal-semiconductor interface, alleviating the current crowding effect, and reducing the generation of local Joule heating. Under forward voltage, the p-type electron blocking layer and the embedded n-type light-absorbing layer can improve the vertical injection efficiency of charge carriers, reduce the possibility of electron leakage into the p-region, thereby reducing the self-heating effect caused by non-radiative recombination and improving the luminous efficiency of the deep ultraviolet LED device. The embedding of the n-type light-absorbing layer realizes photon-hole conversion, solving the serious problem of photon self-absorption effect, thereby improving the photoelectric conversion efficiency.

[0066] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A deep ultraviolet LED device with a photoinduced hole compensation structure, characterized in that, The deep ultraviolet LED device comprises, from bottom to top: a substrate, a buffer layer, an electron transport layer, an active region, an electron blocking layer, a hole injection layer, an n-type light absorption layer, an insulating layer, a p-type ohmic electrode, an n-type ohmic electrode, and a reflector electrode. The electron transport layer is partially exposed, and the upper surface of the exposed portion of the electron transport layer is covered with an n-type ohmic electrode. At least one groove is etched in the hole injection layer, and an n-type light absorption layer is deposited in the groove. The hole injection layer and the n-type light absorption layer are covered with p-type ohmic electrodes.

2. The deep ultraviolet LED device with a photoinduced hole compensation structure according to claim 1, characterized in that, The overall shape of the device includes triangles, circles, rectangles, and rings.

3. A deep ultraviolet LED device with a photoinduced hole compensation structure according to claim 1, characterized in that, The etching depth of each groove is 10 nm-100 nm, the etching width is 5 μm-100 μm, and the area of ​​the groove portion accounts for 10% to 80% of the total area of ​​the hole injection layer and the ohmic contact layer.

4. A deep ultraviolet LED device with a photoinduced hole compensation structure according to claim 1, characterized in that, The substrate material includes at least one of sapphire, SiC, Si, AlN, GaN or quartz glass; the substrate is classified as a polar surface substrate, a semi-polar surface substrate or a non-polar surface substrate according to the different epitaxial growth directions.

5. A deep ultraviolet LED device with a photoinduced hole compensation structure according to claim 1, characterized in that, The buffer layer is made of AlGaN or AlN and has a thickness of 500 nm to 2 μm.

6. A deep ultraviolet LED device with a photoinduced hole compensation structure according to claim 1, characterized in that, The electron transport layer is made of Al. x1 Ga 1-x1 N, where 0≤x1≤1, 0≤1-x1≤1, has a thickness of 1 μm~4 μm, and the exposed portion of the electron transport layer accounts for 5%-80% of the entire electron transport layer.

7. A deep ultraviolet LED device with a photoinduced hole compensation structure according to claim 1, characterized in that, The active region comprises several layers of quantum barriers and quantum wells, with the quantum barriers made of Al. x2 Ga 1-x2 N, 0≤x²≤1, 0≤1-x²≤1; the quantum well is made of Al. x3 Ga 1-x3 N, 0≤x3≤1, 0≤1-x3≤1 and x3≤x2; the thickness of the active region is 10 nm~300 nm.

8. A deep ultraviolet LED device with a photoinduced hole compensation structure according to claim 1, characterized in that, The electron blocking layer is made of Al. x4 Ga 1-x4 N, where 0 ≤ x4 ≤ 1, 0 ≤ 1 - x4 ≤ 1 and x2 ≤ x4; the thickness is 10 nm to 40 nm. The hole injection layer is made of Al. x5 Ga 1-x5 N, where 0 ≤ x5 ≤ 1, 0 ≤ 1 - x5 ≤ 1; thickness is 10 nm ~ 100 nm; The material of the n-type light absorption layer is BN, Ga2O3, ZnO, GaN or AlGaN, and its thickness is 10 nm to 100 nm. The insulating layer material is SiO2, HfO2 or Al2O3, and its thickness is 20 nm to 1 μm.

9. A deep ultraviolet LED device with a photoinduced hole compensation structure according to claim 1, characterized in that, The p-type ohmic electrode is made of Ni / Au, Ni / Al, Cr / Au, or Pt / Au; the n-type ohmic electrode is made of Cr / Al, Al / Au, Cr / Au, or Ti / Al / Ti / Au; and the mirror electrode is made of Al / Ti / Au or Ti / Al / Ti / Au.

10. A method for fabricating a deep ultraviolet LED device with a photoinduced hole compensation structure, used to fabricate the deep ultraviolet LED device with a photoinduced hole compensation structure as described in claims 1-9, characterized in that, The preparation method includes the following steps: S1. First, the substrate is baked at 950℃~1350℃ in an MOCVD reactor to remove foreign matter from the substrate surface. Then, a buffer layer, an electron transport layer, an active region, an electron blocking layer, a hole injection layer, and an ohmic contact layer are grown respectively. S2, on the product obtained in S1, exposes the electron transport layer through photolithography and deep etching, and etches the surface; S3, on the mesa obtained in S2, grooves are etched in the hole injection layer and the ohmic contact layer by photolithography and dry etching processes; S4, based on S3, uses MOCVD or magnetron sputtering technology to grow an n-type light-absorbing layer material in the groove; S5, based on S4, uses photolithography and electron beam evaporation technology to fabricate the n-type ohmic electrode and p-type ohmic electrode of LED; S6, based on S5, uses PECVD or ALD technology to grow an insulating layer with a thickness of 20 nm-1 μm; S7, based on S6, uses photolithography and wet etching techniques to remove the insulating layer covering the n-type ohmic electrode and the p-type ohmic electrode; S8, based on S7, uses photolithography and electron beam evaporation technology to fabricate the reflective electrode of the LED.

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