Mini / micro LED epitaxial quantum well and its manufacturing method and epitaxial structure

Abstract

The present invention discloses an epitaxial quantum well of Mini / micro LED and its manufacturing method and epitaxial structure, wherein the epitaxial quantum well includes a well layer, a cladding layer and a barrier layer, and the well layer is composed of In x Ga 1‑x N, the cladding layer is made of GaN, the barrier layer is made of Si-doped GaN, X = 0.30 to 0.40, and the thickness of the well layer is 1.5 to 2.0 nm. The present invention reduces the influence of the piezoelectric effect by adjusting the structure of the quantum well, increasing the In content of the well layer, reducing the thickness of the well layer, and simultaneously providing the cladding layer and the barrier layer, thereby reducing the half-wave width (Hw) and standard deviation (Stdv) of the epitaxial layer.

Description

Technical Field

[0001] The present invention relates to the technical field of light-emitting diodes, and in particular to an epitaxial quantum well and epitaxial structure of a Mini / micro LED. Background Art

[0002] Mini / micro LEDs are a new type of LED chip with a small size. They offer advantages such as high pixel density and low energy consumption in displays. However, when used on large screens, such as those in cinemas and home TVs, the piezoelectric effect can cause significant wavelength variations with even small variations in the LED chip's current. This can lead to uneven color on large LED screens, significantly impacting visual quality and affecting user experience. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an epitaxial quantum well of Mini / micro LED, which is narrow and deep, effectively reducing the piezoelectric effect and reducing its half-wave width and standard deviation.

[0004] The technical problem that the present invention also aims to solve is to provide a method for manufacturing epitaxial quantum wells of Mini / micro LEDs, thereby reducing the piezoelectric effect of the quantum wells and reducing their half-wave width and standard deviation.

[0005] The technical problem that the present invention also aims to solve is to provide a Mini / micro LED epitaxial structure with a narrow and deep well, which effectively reduces the piezoelectric effect and reduces its half-wave width and standard deviation.

[0006] In order to solve the above technical problems, the present invention provides a Mini / micro LED epitaxial quantum well, including a well layer, a cladding layer and a barrier layer, wherein the well layer is composed of In x Ga 1-x N, the cladding layer is made of GaN, and the barrier layer is made of GaN doped with Si, wherein X=0.30-0.40, and the thickness of the well layer is 1.5-2.0 nm.

[0007] As an improvement to the above-mentioned scheme, the cladding layer includes a first cladding layer and a second cladding layer, the first cladding layer is arranged between the well layer and the second cladding layer, the first cladding layer and the second cladding layer are both made of GaN, wherein the formation temperature of the first cladding layer is lower than the formation temperature of the second cladding layer, the formation temperature of the first cladding layer is 650~750℃, and the formation temperature of the second cladding layer is 750~850℃.

[0008] As an improvement of the above solution, the thickness of the first coating layer is 0.5-1.0 nm, the thickness of the second coating layer is 0.5-1.0 nm, and the total thickness of the coating layer is 1.0-2.0 nm.

[0009] As an improvement to the above solution, the doping concentration of Si in the barrier layer is 1*10 18 ~5*10 18 , the thickness of the barrier layer is 10 to 20 nm.

[0010] As an improvement to the above solution, the half-wave width of the epitaxial quantum well of the Mini / micro LED is 18 to 22, and the standard deviation is 1.5 to 2.

[0011] Accordingly, the present invention also provides a method for fabricating an epitaxial quantum well of a Mini / micro LED, comprising:

[0012] 1. Under the conditions of temperature of 650-750℃ and pressure of 450-550mBar, a layer of In x Ga 1-x N well layer, wherein X = 0.30 to 0.40, and the thickness of the well layer is 1.5 to 2.0 nm;

[0013] 2. forming a first cladding layer made of GaN at a temperature of 650-750° C. and a pressure of 450-550 mBar;

[0014] 3. forming a second cladding layer made of GaN at a temperature of 750-850° C. and a pressure of 450-550 mBar;

[0015] 4. Forming a barrier layer made of Si-doped GaN at a temperature of 750-850° C. and a pressure of 450-550 mBar.

[0016] As an improvement of the above scheme, in step (1), TEGa, TMIn, NH3 and N2 gases are introduced at a temperature of 650-750°C and a pressure of 450-550 mBar, with flow rates of 130-190 sccm, 400-500 sccm, 80-160 sccm and 40-70 sccm, respectively, to form a well layer with a thickness of 1.5-2.0 nm.

[0017] As an improvement to the above scheme, in step (2), TEGa, NH3, N2, and H2 gases are introduced at a temperature of 650-750°C and a pressure of 450-550 mBar at flow rates of 130-190 sccm, 80-160 sccm, 40-70 sccm, and 3-6 sccm, respectively, to form a first coating layer with a thickness of 0.5-1 nm;

[0018] In step (iii), at a temperature of 750-850°C and a pressure of 450-550 mBar, TEGa, NH3, N2 and H2 gases are introduced at flow rates of 130-190 sccm, 80-160 sccm, 40-70 sccm and 3-6 sccm, respectively, to form a second coating layer with a thickness of 0.5-1 nm.

[0019] As an improvement of the above scheme, in step (iv), at a temperature of 750-850°C and a pressure of 450-550 mBar, TEGa, NH3, N2, H2 and SiH4 gases are introduced with flow rates of 300-400 sccm, 80-160 sccm, 40-70 sccm, 4-10 sccm and 40-70 sccm, respectively, to form a barrier layer with a thickness of 10-20 nm.

[0020] Correspondingly, the present invention also provides an epitaxial structure of a Mini / micro LED, comprising a substrate, a buffer layer, a first semiconductor layer, the epitaxial quantum well as described above, and a second semiconductor layer, wherein the buffer layer is arranged on the first semiconductor layer, the first semiconductor layer is arranged on the buffer layer, the epitaxial quantum well is arranged on the first semiconductor layer, and the second semiconductor layer is arranged on the epitaxial quantum well.

[0021] The implementation of the present invention has the following beneficial effects:

[0022] The present invention adjusts the structure of the quantum well, increases the In content of the well layer, and reduces the thickness of the well layer, making the well narrow and deep, thereby reducing the impact of the piezoelectric effect and further reducing the half-wave width (Hw) and standard deviation (Stdv) of the epitaxial layer. Since the In content in the well layer of the present invention is increased and the thickness of the well layer is reduced, in order to prevent In from diffusing into other layers and causing wavelength dispersion, the present invention provides a cladding layer on the well layer to further reduce defects and prevent In migration, thereby improving wavelength consistency and piezoelectric wavelength offset. Specifically, the Hw of the epitaxial quantum well of the present invention is 18-22, and the Stdv is 1.5-2.

[0023] The cladding layer of the present invention separates the first cladding layer and the second cladding layer. During the two growth processes, there is a pause in between, which is conducive to surface reorganization and refilling of defects. In addition, the formation temperature of the second cladding layer of the present invention is higher than the formation temperature of the first cladding layer, which can further reduce the size of defects and make it difficult for In to penetrate. Furthermore, when forming the first cladding layer and the second cladding layer of the quantum well of the present invention, H2 is added for purging, mainly to clear In that penetrates the well layer and prevent the half-wave width from increasing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic structural diagram of the quantum well of the present invention;

[0025] Figure 2 This is a schematic diagram of the energy levels of existing blue light quantum wells;

[0026] Figure 3 Schematic diagram of the energy levels of the quantum well of the present invention;

[0027] Figure 4 is a graph showing the corresponding wavelengths of multiple samples at different currents according to Example 1 of the present invention;

[0028] Figure 5 This is a graph showing the corresponding wavelengths of multiple samples in comparative example 1 of the present invention at different currents. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below with reference to the accompanying drawings.

[0030] See also Figure 1 The present invention provides a Mini / micro LED epitaxial quantum well, comprising a well layer 10, a cladding layer 20 and a barrier layer 30, wherein the well layer 10 is made of In x Ga 1-x N, the cladding layer 20 is made of GaN, and the barrier layer 30 is made of GaN doped with Si.

[0031] The thickness of each layer in the quantum well of the present invention has an important influence on the various properties of the quantum well. Among them, if the thickness of the well layer 10 is too wide, the internal stress of the material itself increases, and the wavelength variation emitted by the epitaxial layer increases, that is, the piezoelectric effect of the epitaxial layer increases, and the In content in the well layer 10 is likely to be uneven, affecting the photoelectric effect; if the thickness of the well layer 10 is too narrow, the quantum effect of the epitaxial layer deteriorates and the brightness decreases.

[0032] The coating layer 20 of the present invention is used to protect the well layer 10, and its thickness must match the thickness of the well layer 10. If the thickness is too thick, it will produce internal stress effects, pulling the shape of the well layer 10 and making it easy to deform; if the thickness is too thin, it will not protect the well layer 10, and the well layer 10 will be easily affected by high temperature.

[0033] The barrier layer 30 of the present invention mainly plays the role of isolation and blocking, so its thickness also has certain requirements.

[0034] Preferably, the thickness of the well layer 10 is 1.5 to 2.0 nm, the thickness of the cladding layer 20 is 1.0 to 2.0 nm, and the thickness of the barrier layer 30 is 10 to 20 nm.

[0035] More preferably, the thickness of the well layer 10 is 1.5-1.8 nm, the thickness of the cladding layer 20 is 1.0-1.6 nm, and the thickness of the barrier layer 30 is 10-18 nm.

[0036] More preferably, the thickness of the well layer 10 is 1.6-1.8 nm, the thickness of the cladding layer 20 is 1.2-1.6 nm, and the thickness of the barrier layer 30 is 15-18 nm.

[0037] It should be noted that the well layer 10 , the cladding layer 20 and the barrier layer 30 of the quantum well of the present invention are equivalent to a stacked structure of well+cap+barrier.

[0038] The existing blue light quantum well includes the first In x Ga 1-x N layer, a second InGaN layer and a GaN layer, such as Figure 2 As shown, the structure is equivalent to a well layer / shell well / barrier layer stack, with thicknesses of 2.5-3.5nm / 1-1.5nm / 7.5-10.5nm. The shell well, also known as the barrier layer, is a protective layer with a slowly varying In content outside the quantum well. This protects the quantum well and mitigates the mismatch between the well layer and the barrier layer. However, the barrier layer increases the epitaxial Hw and stdv.

[0039] It should be noted that in the quantum well layer 10, the size of X indicates the In content. A larger X indicates a higher In content, a lower energy level, and a longer wavelength of light emitted by the quantum well. In existing quantum well fabrication methods, increasing the In content in the well layer inevitably increases the wavelength of light emitted by the quantum well. Furthermore, In in the well layer easily migrates to other layers, affecting the crystal quality of the quantum well or epitaxial layer.

[0040] It should be noted that the "width" of the well refers to the thickness of the well layer. The smaller the thickness of the well layer, the narrower the well, and the thicker the well layer, the wider the well. The "depth" of the well refers to the In content in the well layer. The more In content, the deeper the well, and the less In content, the shallower the well.

[0041] The well layer of existing blue light LEDs has a relatively low In content, with X generally being 0.20-0.25 and a thickness of 2.5-3.5 nm. The well is wide and shallow, and the In content in the peripheral wells gradually decreases from the same In content as in the well layer to 0. Figure 2 shown.

[0042] In the well layer 10 of the present invention, X=0.30-0.40, the thickness is 1.5-2.0 nm, the well is narrow and deep, as shown in FIG. Figure 3 shown.

[0043] The present invention mainly forms a special cladding layer 20 and a barrier layer 30 on the well layer 10, and protects the well layer 10 through the cladding layer 20, while preventing In in the well layer 10 from penetrating into the cladding layer 20 and the barrier layer 30. Therefore, the well layer 10 of the present invention can achieve a narrow and deep well.

[0044] When X in the well layer 10 of the present invention is 0.30-0.35, the In content of the well in the quantum well of the present invention has reached the green light band, but can still emit blue light band.

[0045] When X in the well layer 10 of the present invention is 0.35-0.40, the In content of the well in the quantum well of the present invention reaches the yellow light or red light band, but can still emit green light band.

[0046] In order to further improve the effect of the cladding layer, the cladding layer 20 of the present invention includes a first cladding layer 21 and a second cladding layer 22, wherein the first cladding layer 21 is arranged between the well layer 10 and the second cladding layer 22, and the first cladding layer 21 and the second cladding layer 22 are both made of GaN, wherein the formation temperature of the first cladding layer 21 is lower than the formation temperature of the second cladding layer 22.

[0047] Although the first cladding layer 21 and the second cladding layer 22 of the present invention are made of the same material, they are formed twice separately. The pause in between allows the surface of the growing crystal to be restructured, allowing unstable atoms to move to lower energy levels to form a stable state. Defects are filled by stable atoms, thereby reducing defects.

[0048] In addition, the formation temperature of the second cladding layer 22 of the present invention is higher than that of the first cladding layer 21 , which can further reduce the size of defects and make it difficult for In to penetrate, thereby improving wavelength consistency and piezoelectric wavelength shift.

[0049] In the barrier layer 30 of the present invention, the doping concentration of Si is 1*1018 ~8*10 18 If the Si doping concentration is too low, the voltage of the epitaxial layer will increase. If the Si doping concentration is too high, the epitaxial layer will easily produce defects or even leakage.

[0050] Preferably, in the barrier layer 30 of the present invention, the doping concentration of Si is 1*10 18 ~5*10 18 .

[0051] More preferably, in the barrier layer 30 of the present invention, the doping concentration of Si is 2*10 18 ~4*10 18 .

[0052] The present invention adjusts the structure of the quantum well, increases the In content of the well layer, reduces the thickness of the well layer, and simultaneously provides a cladding layer and a barrier layer, thereby reducing the influence of the piezoelectric effect and further reducing the half-wave width (Hw) and standard deviation (Stdv) of the epitaxial layer. Specifically, the Hw of the epitaxial quantum well of the present invention is 18 to 22, and the Stdv is 1.5 to 2.

[0053] Specifically, the preparation method of the quantum well of the present invention is as follows:

[0054] 1. Using MOCVD technology, a well layer is formed at a temperature of 650-750°C and a pressure of 450-550 mBar.

[0055] Specifically, under the conditions of temperature of 650-750°C and pressure of 450-550mBar, TEGa, TMIn, NH3 and N2 gases are introduced with flow rates of 130-190sccm, 400-500sccm, 80-160sccm and 40-70sccm respectively to form a well layer with a thickness of 1.5-2.0nm.

[0056] Preferably, under the conditions of a temperature of 650-750°C and a pressure of 480-520 mBar, TEGa, TMIn, NH3 and N2 gases are introduced with flow rates of 140-170 sccm, 420-480 sccm, 100-140 sccm and 40-60 sccm, respectively, to form a well layer with a thickness of 1.5-1.8 nm.

[0057] More preferably, at a temperature of 650-750°C and a pressure of 500-520 mBar, TEGa, TMIn, NH3 and N2 gases are introduced with flow rates of 160 sccm, 450 sccm, 120 sccm and 65 sccm respectively to form a well layer with a thickness of 1.6-1.8 nm.

[0058] 2. forming a first coating layer at a temperature of 650-750° C. and a pressure of 450-550 mBar;

[0059] Specifically, under the conditions of temperature of 650-750°C and pressure of 450-550mBar, TEGa, NH3, N2 and H2 gases are introduced with flow rates of 130-190sccm, 80-160sccm, 40-70sccm and 3-6sccm respectively to form a first coating layer with a thickness of 0.5-1nm.

[0060] Preferably, under the conditions of temperature of 650-750°C and pressure of 480-520mBar, TEGa, NH3, N2 and H2 gases are introduced with flow rates of 140-170sccm, 100-140sccm, 40-60sccm and 3-5sccm respectively to form a first coating layer with a thickness of 0.5-0.8nm.

[0061] More preferably, at a temperature of 650-750°C and a pressure of 500-520 mBar, TEGa, NH3, N2 and H2 gases are introduced with flow rates of 160 sccm, 120 sccm, 65 sccm and 4.5 sccm respectively to form a first coating layer with a thickness of 0.6-0.8 nm.

[0062] 3. forming a second coating layer at a temperature of 750-850° C. and a pressure of 450-550 mBar;

[0063] Specifically, under the conditions of temperature of 750-850°C and pressure of 450-550mBar, TEGa, NH3, N2 and H2 gases are introduced with flow rates of 130-190sccm, 80-160sccm, 40-70sccm and 3-6sccm respectively to form a second coating layer with a thickness of 0.5-1nm.

[0064] Preferably, under the conditions of temperature of 750-850°C and pressure of 480-520mBar, TEGa, NH3, N2 and H2 gases are introduced with flow rates of 140-170sccm, 100-140sccm, 40-60sccm and 3-5sccm respectively to form a second coating layer with a thickness of 0.5-0.8nm.

[0065] More preferably, at a temperature of 750-850°C and a pressure of 500-520 mBar, TEGa, NH3, N2 and H2 gases are introduced with flow rates of 160 sccm, 120 sccm, 65 sccm and 4.5 sccm respectively to form a second coating layer with a thickness of 0.6-0.8 nm.

[0066] 4. Forming a barrier layer at a temperature of 750-850°C and a pressure of 450-550 mBar;

[0067] Specifically, under the conditions of temperature of 750-850°C and pressure of 450-550mBar, TEGa, NH3, N2, H2 and SiH4 gases are introduced with flow rates of 300-400sccm, 80-160sccm, 40-70sccm, 4-10sccm and 40-70sccm, respectively, to form a barrier layer with a thickness of 10-20nm.

[0068] Preferably, under the conditions of a temperature of 750-850°C and a pressure of 480-520 mBar, TEGa, NH3, N2, H2 and SiH4 gases are introduced with flow rates of 320-380 sccm, 100-140 sccm, 40-60 sccm, 4-8 sccm and 40-60 sccm, respectively, to form a barrier layer with a thickness of 10-18 nm.

[0069] More preferably, at a temperature of 750-850°C and a pressure of 500-520 mBar, TEGa, NH3, N2, H2 and SiH4 gases are introduced with flow rates of 340 sccm, 120 sccm, 65 sccm, 6 sccm and 50 sccm respectively to form a barrier layer with a thickness of 15-18 nm.

[0070] During the formation of the first and second cladding layers of the quantum well of the present invention, H2 is added for purging, primarily to remove In that has infiltrated the well layers and prevent the half-wave width from increasing. Preferably, the H2 flow rate is 3-6 sccm. Excessive H2 flow rates can affect the formation of the first and second cladding layers, while too low H2 flow rates can have no purging effect.

[0071] Although the first and second cladding layers of the present invention are made of the same material, they are formed twice separately. The pause in between allows the surface of the growing crystal to be restructured, allowing unstable atoms to move to lower energy levels to form a stable state. Defects are filled by stable atoms, thereby reducing defects.

[0072] Preferably, there is a pause of 30 to 180 seconds between forming the first cladding layer and forming the second cladding layer. If the pause time is too long, other impurities will also be deposited on the first cladding layer, which will affect the crystal quality of the epitaxial structure.

[0073] Correspondingly, the present invention also provides a Mini / micro LED epitaxial structure, including a substrate, a buffer layer, a first semiconductor layer, the above-mentioned epitaxial quantum well, and a second semiconductor layer, wherein the buffer layer is arranged on the first semiconductor layer, the first semiconductor layer is arranged on the buffer layer, the epitaxial quantum well is arranged on the first semiconductor layer, and the second semiconductor layer is arranged on the epitaxial quantum well.

[0074] The present invention will be further described below with reference to specific embodiments.

[0075] Example 1

[0076] A Mini / micro LED epitaxial quantum well comprises a well layer, a first cladding layer, a second cladding layer and a barrier layer, wherein the well layer is made of In 0.33 Ga 0.67 N, the first cladding layer and the first cladding layer are both made of GaN, the barrier layer is made of GaN doped with Si, and the doping concentration of Si is 3*10 18 The thickness of the well layer is 1.6 nm, the thickness of the first cladding layer is 0.6 nm, the thickness of the second cladding layer is 0.6 nm, and the thickness of the barrier layer is 16 nm.

[0077] Comparative Example 1

[0078] A blue light epitaxial quantum well, including In 0.22 Ga 0.78 N / InGaN / GaN, thicknesses are 3.0nm / 1.2nm / 8.5nm.

[0079] See also Figure 4 The epitaxial structure made of the epitaxial quantum well of Example 1 has a wavelength of about 462.4nm when a small current (0.8mA) is passed through it, and a wavelength of about 462.1nm when a large current (5mA) is passed through it. The difference between the two is about 0.3nm.

[0080] See also Figure 5 In the epitaxial structure made of the epitaxial quantum well of comparative example 1, when a small current (0.8 mA) is passed, the wavelength is about 466 nm, and when a large current (5 mA) is passed, the wavelength is about 461.7 nm, and the difference between the two is about 4.23 nm.

[0081] It can be seen that the epitaxial quantum well of the present invention reduces the influence of the piezoelectric effect by adjusting the structure of the quantum well, increasing the In content of the well layer, reducing the thickness of the well layer, and setting a cladding layer and a barrier layer, thereby effectively reducing the half-wave width and standard deviation.

[0082] The above disclosure is only a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. An epitaxial quantum well of a Mini / micro LED, characterized in that: It includes a well layer, a cladding layer and a barrier layer stacked in sequence, wherein the well layer is made of In x Ga 1-x N, the cladding layer includes a first cladding layer and a second cladding layer, the first cladding layer is arranged between the well layer and the second cladding layer, the first cladding layer and the second cladding layer are both made of GaN, and the barrier layer is made of GaN doped with Si, wherein x=0.30-0.40, and the thickness of the well layer is 1.5-2.0 nm; The first cladding layer is prepared by the following method: at a temperature of 650-750° C. and a pressure of 450-550 mBar, TEGa, NH 3 , N 2 , and H 2 gases are introduced at flow rates of 130-190 sccm, 80-160 sccm, 40-70 sccm, and 3-6 sccm, respectively, to form a first cladding layer with a thickness of 0.5-1 nm; The second cladding layer is prepared by the following method: at a temperature of 750-850° C. and a pressure of 450-550 mBar, TEGa, NH 3 , N 2 , and H 2 gases are introduced at flow rates of 130-190 sccm, 80-160 sccm, 40-70 sccm, and 3-6 sccm, respectively, to form a second cladding layer with a thickness of 0.5-1 nm; The formation temperature of the first coating layer is lower than the formation temperature of the second coating layer, and there is a pause of 30 to 180 seconds between the formation of the first coating layer and the formation of the second coating layer.

2. The epitaxial quantum well of the Mini / micro LED according to claim 1, wherein: The thickness of the first coating layer is 0.5-1.0 nm, the thickness of the second coating layer is 0.5-1.0 nm, and the total thickness of the coating layer is 1.0-2.0 nm.

3. The epitaxial quantum well of the Mini / micro LED according to claim 1, wherein: The thickness of the barrier layer is 10-20 nm.

4. A method for fabricating an epitaxial quantum well of a Mini / micro LED, characterized in that: The following steps are involved: (1) Under the conditions of temperature of 650~750℃ and pressure of 450~550mBar, a layer of In x Ga 1-x N well layer, wherein X=0.30-0.40, and the thickness of the well layer is 1.5-2.0 nm; (2) at a temperature of 650-750°C and a pressure of 450-550 mBar, introducing TEGa, NH3, N2, and H2 gases at flow rates of 130-190 sccm, 80-160 sccm, 40-70 sccm, and 3-6 sccm, respectively, to form a first cladding layer made of GaN with a thickness of 0.5-1 nm, and pausing for 30-180 seconds; (3) at a temperature of 750°C to 850°C and a pressure of 450 to 550 mBar, introducing TEGa, NH3, N2, and H2 gases at flow rates of 130 to 190 sccm, 80 to 160 sccm, 40 to 70 sccm, and 3 to 6 sccm, respectively, to form a second cladding layer made of GaN with a thickness of 0.5 to 1 nm; (4) forming a barrier layer made of Si-doped GaN at a temperature of 750-850°C and a pressure of 450-550 mBar; The formation temperature of the first coating layer is lower than the formation temperature of the second coating layer.

5. The method for fabricating a Mini / micro LED epitaxial quantum well according to claim 4, wherein: In step (1), TEGa, TMIn, NH3, and N2 gases are introduced at a temperature of 650-750°C and a pressure of 450-550 mBar at flow rates of 130-190 sccm, 400-500 sccm, 80-160 sccm, and 40-70 sccm, respectively, to form a well layer with a thickness of 1.5-2.0 nm.

6. The method for fabricating a Mini / micro LED epitaxial quantum well according to claim 4, wherein: In step (iv), TEGa, NH3, N2, H2, and SiH4 gases are introduced at a temperature of 750-850°C and a pressure of 450-550 mBar at flow rates of 300-400 sccm, 80-160 sccm, 40-70 sccm, 4-10 sccm, and 40-70 sccm, respectively, to form a barrier layer with a thickness of 10-20 nm.

7. A Mini / micro LED epitaxial structure, characterized in that: It includes a substrate, a buffer layer, a first semiconductor layer, the epitaxial quantum well according to any one of claims 1 to 3, and a second semiconductor layer, wherein the buffer layer is arranged on the first semiconductor layer, the first semiconductor layer is arranged on the buffer layer, the epitaxial quantum well is arranged on the first semiconductor layer, and the second semiconductor layer is arranged on the epitaxial quantum well.

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