High-color-gamut LED epitaxial wafer, preparation method thereof and LED chip

Abstract

The invention provides a high-color-gamut LED epitaxial wafer, a preparation method thereof and an LED chip, and relates to the technical field of semiconductor devices, the high-color-gamut LED epitaxial wafer comprises a substrate and an epitaxial layer stacked on the substrate, the epitaxial layer comprises a buffer layer, a three-dimensional GaN layer, an undoped GaN layer, an N-type GaN layer, a stress release layer, a multi-quantum well layer, an electron blocking layer and a P-type GaN layer which are stacked in sequence, the multi-quantum well layer comprises a green light multi-quantum well layer and a blue light multi-quantum well layer stacked on the green light multi-quantum well layer, an insertion layer is arranged between the green light multi-quantum well layer and the blue light multi-quantum well layer, and the insertion layer is a P-type doped GaN layer. The color gamut is low or the edge color difference is caused.

Description

Technical Field

[0001] This invention relates to the field of semiconductor device technology, specifically to a high color gamut LED epitaxial wafer and its preparation method, and an LED chip. Background Technology

[0002] LED chips are light-emitting semiconductor electronic components characterized by their small size, high brightness, and low power consumption, and are widely used in lighting and other fields. LED chips are obtained by splitting LED epitaxial wafers. An LED epitaxial wafer includes a substrate and a GaN epitaxial layer grown on the substrate.

[0003] Currently, in the backlighting field, LED chips are used as backlight sources, such as in television backlights. Maximizing color reproduction, or color gamut, is crucial for improving the realism and viewing experience of the television picture. A common method to improve the color gamut is to use a single blue LED chip paired with phosphors. White light is achieved by exciting phosphors at different wavelengths. However, since a single LED chip excites the phosphor, it cannot cover the entire wavelength range, resulting in a lower color gamut and thus a poorer picture display. Another method involves using two or more LED chips with different wavelengths paired with phosphors. However, this method can lead to edge color differences, affecting the final visual effect, and it is also more expensive. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a high color gamut LED epitaxial wafer and its preparation method, as well as an LED chip, in order to solve the technical problem that the use of blue LED chips with phosphors or multiple chips to improve the color gamut in existing technologies results in a low color gamut or edge color difference.

[0005] A first aspect of the present invention is to provide a high color gamut LED epitaxial wafer, the high color gamut LED epitaxial wafer comprising a substrate and an epitaxial layer stacked on the substrate, the epitaxial layer comprising, in sequence, a buffer layer, a three-dimensional GaN layer, an undoped GaN layer, an N-type GaN layer, a stress relief layer, a multiple quantum well layer, an electron blocking layer, and a P-type GaN layer. The multiple quantum well layer includes a green quantum well layer and a blue quantum well layer stacked on top of the green quantum well layer, with an insertion layer between the green quantum well layer and the blue quantum well layer. The insertion layer is a P-type doped GaN layer.

[0006] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By stacking green and blue quantum well layers, green and blue light can be emitted directly and efficiently without the need for a single blue LED to excite phosphor or multiple chip combinations. This can fully cover the visible light band, greatly improve the color gamut, and better restore the realism and color richness of the image.

[0007] 2. An insertion layer is provided between the green light multi-quantum well layer and the blue light multi-quantum well layer. The insertion layer is a P-type doped GaN layer. On the one hand, the P-type doped GaN layer provides holes in the middle to increase recombination in the green light multi-quantum well layer, thereby simultaneously improving the luminous efficiency of blue and green light. On the other hand, the P-type doped GaN layer isolates the green light multi-quantum well layer and the blue light multi-quantum well layer, avoiding carrier crosstalk, ensuring the independence and stability of dual-band light emission, and eliminating edge color difference in multi-chip solutions.

[0008] 3. The single-chip integration of dual quantum well layers and insertion layers simplifies the process, eliminates the need for multi-chip packaging and assembly, reduces costs, and ensures process compatibility for mass production, improving yield and reliability. It achieves high color gamut, no edge color difference, low cost, and high luminous efficiency backlight LED effects, meeting the image quality and economic requirements of display devices. This solves the technical problem in existing technologies where using blue LED chips with phosphors or multiple chips to improve the color gamut results in a low color gamut or edge color difference.

[0009] According to one aspect of the above technical solution, the blue light multi-quantum well layer includes periodically alternating InGaN layers and GaN layers with a period number of 1 to 15. The In composition ratio in the InGaN layer is 0.1 to 0.2, the thickness of the InGaN layer is 2 nm to 4 nm, and the thickness of the GaN layer is 8 nm to 12 nm.

[0010] According to one aspect of the above technical solution, the green light multi-quantum well layer includes periodically alternating InGaN layers and GaN layers with a period number of 1 to 15. The In composition ratio in the InGaN layer is 0.2 to 0.3, the thickness of the InGaN layer is 2 nm to 4 nm, and the thickness of the GaN layer is 8 nm to 12 nm.

[0011] According to one aspect of the above technical solution, the dopant of the P-type doped GaN layer is magnesium, and the doping concentration is 1×10⁻⁶. 19 cm -3 ~1×10 20 cm -3 .

[0012] According to one aspect of the above technical solution, the thickness of the P-type doped GaN layer is 2nm~10nm.

[0013] According to one aspect of the above technical solution, the substrate is a sapphire substrate.

[0014] According to one aspect of the above technical solution, the buffer layer is a GaN layer with a thickness of 15nm~35nm, the stress relief layer includes periodically alternating InGaN layers and GaN layers, and the electron blocking layer includes periodically alternating AlGaN layers and GaN layers.

[0015] A second aspect of the present invention is to provide a method for preparing a high color gamut LED epitaxial wafer, the method being used to prepare the aforementioned high color gamut LED epitaxial wafer, the method comprising: Provide a substrate; A buffer layer, a three-dimensional GaN layer, an undoped GaN layer, an N-type GaN layer, and a stress relief layer are epitaxially grown sequentially on the substrate. A green light multi-quantum well layer, an insertion layer, and a blue light multi-quantum well layer are epitaxially grown sequentially on the stress relief layer, wherein the insertion layer is a P-type doped GaN layer. An electron blocking layer and a P-type GaN layer are then epitaxially grown on the blue light multi-quantum layer.

[0016] Furthermore, the growth temperature of the P-type doped GaN layer is 800℃~1000℃, and the growth pressure is 100 torr~500 torr.

[0017] A third aspect of the present invention is to provide an LED chip comprising the above-described high color gamut LED epitaxial wafer. Attached Figure Description

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the high color gamut LED epitaxial wafer structure in this invention; Figure 2 The images show the spectral test results of the LED chips prepared in Example 1 and Comparative Example 1 of this invention. Component symbol explanation in the attached diagram: Substrate 10, buffer layer 20, three-dimensional GaN layer 30, undoped GaN layer 40, N-type GaN layer 50, stress relief layer 60, multiple quantum well layer 70, green light multiple quantum well layer 71, blue light multiple quantum well layer 72, insertion layer 73, electron blocking layer 80, P-type GaN layer 90. Detailed Implementation

[0019] To make the objectives, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0020] Please see Figure 1The image shows a high color gamut LED epitaxial wafer provided by the present invention. The high color gamut LED epitaxial wafer includes a substrate 10 and an epitaxial layer stacked on the substrate 10. The epitaxial layer includes a buffer layer 20, a three-dimensional GaN layer 30, an undoped GaN layer 40, an N-type GaN layer 50, a stress relief layer 60, a multiple quantum well layer 70, an electron blocking layer 80, and a P-type GaN layer 90, stacked sequentially. The multiple quantum well layer 70 includes a green quantum well layer 71 and a blue quantum well layer 72 stacked on top of the green quantum well layer 71, with an insertion layer 73 between the green quantum well layer 71 and the blue quantum well layer 70.

[0021] It should be noted that stacking green and blue multi-quantum wells enables simultaneous emission of both blue and green light in a dual-band manner, providing a foundation for multi-color light sources such as white LEDs. Green and blue multi-quantum wells are directly integrated within the same chip, utilizing each type of quantum well to efficiently emit green and blue light (both key primary / complementary colors in the visible light spectrum). Compared to the indirect emission of phosphors by blue light excitation, the dual quantum wells can autonomously achieve direct and efficient emission of multiple primary colors, providing more comprehensive coverage of the visible light spectrum, thus significantly improving the color gamut and better restoring the realism and color richness of the image. Furthermore, it eliminates the need for multiple independent LED chips; all emitting layers (green multi-quantum well layer 71 and blue multi-quantum well layer 72) are integrated within the same chip, sharing the substrate 10 and electrode structures. This avoids the problem of poor matching of luminous intensity and wavelength between multiple chips, eliminating edge color differences from the source and ensuring visual consistency of the image.

[0022] The blue light multi-quantum well layer 72 includes periodically alternating InGaN and GaN layers with a period number of 1 to 15. The In composition of the InGaN layer is 0.1 to 0.2%, the thickness of the InGaN layer is 2 nm to 4 nm, and the thickness of the GaN layer is 8 nm to 12 nm.

[0023] The green light multi-quantum well layer 71 includes periodically alternating InGaN and GaN layers with a period number of 1 to 15. The In composition of the InGaN layer is 0.2 to 0.3%, the thickness of the InGaN layer is 2 nm to 4 nm, and the thickness of the GaN layer is 8 nm to 12 nm.

[0024] It should be noted that because the green quantum well layer 71 is far from the p-type GaN layer 90, a large number of holes cannot migrate from the p-type GaN layer 90 to the green quantum well layer 71 and recombine with electrons to emit light, thus greatly affecting the luminous efficiency of the green quantum well layer 71; while if the green quantum well layer 71 is placed close to the p-type GaN layer 90, the luminous efficiency of blue light will be greatly affected.

[0025] Therefore, an insertion layer 73 is provided between the green light multi-quantum well layer 71 and the blue light multi-quantum well layer 70. The insertion layer 73 is a p-type doped GaN layer. The introduction of the insertion layer 73 can provide holes in the middle to increase recombination in the green light multi-quantum well layer 71, thereby simultaneously improving the luminous efficiency of blue and green light. In addition, the p-type doped GaN layer can regulate the charge distribution of the two quantum wells, reduce carrier crosstalk between the green and blue light quantum wells (avoiding the decrease in recombination efficiency or wavelength shift caused by random transport of electrons / holes between layers), and make the luminescence of the green light multi-quantum well layer 71 and the blue light multi-quantum well layer 72 more independent and the wavelength more stable, ensuring the color purity and spectral consistency of the blue and green light output.

[0026] Furthermore, the dopant of the p-type doped GaN layer is magnesium, and the doping concentration is 1×10⁻⁶. 19 ~1×10 20 cm -3 It belongs to the high-concentration doping range, which can effectively ensure sufficient hole supply, match the electron concentration in the quantum well, maximize the radiative recombination probability, and thus significantly improve luminescence efficiency (internal quantum efficiency).

[0027] Furthermore, the thickness of the p-type doped GaN layer is 2nm~10nm. This not only provides electrical functionality but also, due to its ultra-thin design, significantly reduces the accumulation of lattice mismatch stress between GaN and adjacent InGaN / GaN quantum wells, improving the crystal quality and device lifetime of the multi-quantum-well structure. Moreover, the p-type doped GaN layer improves the interface characteristics between the green-light multi-quantum-well layer 71 and the blue-light multi-quantum-well layer 72, reducing carrier trapping by interface states (defect energy levels) and further reducing non-radiative recombination losses.

[0028] Furthermore, the substrate 10 is a sapphire substrate 10.

[0029] Furthermore, the buffer layer 20 is a GaN layer with a thickness of 15nm~35nm, such as 20nm, 25nm, 30nm, etc.

[0030] In addition, the three-dimensional GaN layer 30 is a three-dimensionally grown GaN layer with a thickness of 500nm~2000nm, such as 800nm, 1000nm, 1500nm, etc.

[0031] For example, and not a limitation, the thickness of the undoped GaN layer 40 is 800nm~1200nm, such as 900nm, 1000nm, 1100nm, etc.; the thickness of the N-type GaN layer 50 is 1000nm~3000nm, such as 1500nm, 2000nm, 2500nm, etc.; and the thickness of the P-type GaN layer 90 is 5nm~100nm, such as 10nm, 40nm, 80nm, etc.

[0032] Furthermore, the stress relief layer 60 includes periodically alternating layers of InGaN and GaN with a thickness of 10nm to 50nm, such as 20nm, 30nm, 40nm, etc., and the electron blocking layer 80 includes periodically alternating layers of AlGaN and GaN with a thickness of 2nm to 60nm, such as 30nm, 40nm, 50nm, etc.

[0033] Accordingly, the present invention also provides a method for preparing a high color gamut LED epitaxial wafer, the method comprising: steps S10 to S13.

[0034] Step S10: Provide a substrate; Step S11: A buffer layer, a three-dimensional GaN layer, an undoped GaN layer, an N-type GaN layer, and a stress relief layer are epitaxially grown sequentially on the substrate. Step S12: A green light multi-quantum well layer, an insertion layer, and a blue light multi-quantum well layer are epitaxially grown sequentially on the stress relief layer. The insertion layer is a P-type doped GaN layer. The growth temperature of the P-type doped GaN layer is 800℃~1000℃, and the growth pressure is 100 torr~500 torr.

[0035] Step S13: Continue to epitaxially grow an electron blocking layer and a P-type GaN layer on the blue light multi-quantum layer.

[0036] In addition, the present invention also provides an LED chip, the LED chip comprising the above-mentioned high color gamut LED epitaxial wafer.

[0037] The technical solution of the present invention will now be described in detail with reference to specific embodiments.

[0038] Example 1 The first embodiment of the present invention provides a high color gamut LED epitaxial wafer, the high color gamut LED epitaxial wafer comprising: The high color gamut LED epitaxial wafer includes a substrate and an epitaxial layer stacked on the substrate. The epitaxial layer includes a buffer layer, a three-dimensional GaN layer, an undoped GaN layer, an N-type GaN layer, a stress relief layer, a multiple quantum well layer, an electron blocking layer, and a P-type GaN layer stacked sequentially. The multiple quantum well layer includes a green quantum well layer and a blue quantum well layer stacked on top of the green quantum well layer, with an insertion layer between the green quantum well layer and the blue quantum well layer. The insertion layer is a P-type doped GaN layer.

[0039] The blue light multi-quantum well layer includes periodically alternating InGaN and GaN layers with a period number of 1 to 15. The In composition of the InGaN layer is 0.1 to 0.2%, the thickness of the InGaN layer is 2 nm to 4 nm, and the thickness of the GaN layer is 8 nm to 12 nm.

[0040] The green light multi-quantum well layer consists of periodically alternating InGaN and GaN layers with a period number of 1 to 15. The In content of the InGaN layer is 0.2 to 0.3%, the thickness of the InGaN layer is 2 nm to 4 nm, and the thickness of the GaN layer is 8 nm to 12 nm.

[0041] Furthermore, the dopant of the p-type doped GaN layer is magnesium, and the doping concentration is 5 × 10⁻⁶. 19 cm -3 .

[0042] In addition, the thickness of the p-type doped GaN layer is 6 nm.

[0043] Furthermore, the substrate is a sapphire substrate.

[0044] Furthermore, the buffer layer is a GaN layer with a thickness of 25 nm.

[0045] In addition, the three-dimensional GaN layer is a three-dimensionally grown GaN layer with a thickness of 1500 nm.

[0046] As an example, not a limitation, the thickness of an undoped GaN layer is 1000 nm, the thickness of an N-type GaN layer is 2000 nm, and the thickness of a P-type GaN layer is 50 nm.

[0047] Furthermore, the stress relief layer comprises periodically alternating InGaN and GaN layers with a thickness of 30 nm, and the electron blocking layer comprises periodically alternating AlGaN and GaN layers with a thickness of 40 nm.

[0048] Accordingly, the present invention also provides a method for preparing a high color gamut LED epitaxial wafer, the method comprising: steps S10 to S13.

[0049] Step S10: Provide a substrate; Step S11: A buffer layer, a three-dimensional GaN layer, an undoped GaN layer, an N-type GaN layer, and a stress relief layer are epitaxially grown sequentially on the substrate. Step S12: A green light multi-quantum well layer, an insertion layer, and a blue light multi-quantum well layer are epitaxially grown sequentially on the stress relief layer. The insertion layer is a P-type doped GaN layer. The growth temperature of the P-type doped GaN layer is 900℃, and the growth pressure is 300 torr.

[0050] Step S13: Continue to epitaxially grow an electron blocking layer and a P-type GaN layer on the blue light multi-quantum layer.

[0051] Example 2 Embodiment 2 of the present invention also proposes a high color gamut LED epitaxial wafer. The difference between the high color gamut LED epitaxial wafer in this embodiment and the high color gamut LED epitaxial wafer in Embodiment 1 is that: The doping concentration of the P-type doped GaN layer is 3 × 10⁻⁶. 19 cm -3 The thickness is 2nm.

[0052] Example 3 Embodiment 3 of the present invention also proposes a high color gamut LED epitaxial wafer. The difference between the high color gamut LED epitaxial wafer in this embodiment and the high color gamut LED epitaxial wafer in Embodiment 1 is that: The doping concentration of the P-type doped GaN layer is 3 × 10⁻⁶. 19 cm -3 The thickness is 4nm.

[0053] Example 4 Embodiment 4 of the present invention also proposes a high color gamut LED epitaxial wafer. The difference between the high color gamut LED epitaxial wafer in this embodiment and the high color gamut LED epitaxial wafer in Embodiment 1 is that: The doping concentration of the P-type doped GaN layer is 3 × 10⁻⁶. 19 cm -3 The thickness is 6nm.

[0054] Example 5 Embodiment 5 of the present invention also proposes a high color gamut LED epitaxial wafer. The difference between the high color gamut LED epitaxial wafer in this embodiment and the high color gamut LED epitaxial wafer in Embodiment 1 is that: The doping concentration of the P-type doped GaN layer is 3 × 10⁻⁶. 19 cm -3 The thickness is 8nm.

[0055] Example 6 Embodiment 6 of the present invention also proposes a high color gamut LED epitaxial wafer. The difference between the high color gamut LED epitaxial wafer in this embodiment and the high color gamut LED epitaxial wafer in Embodiment 1 is that: The doping concentration of the P-type doped GaN layer is 3 × 10⁻⁶. 19 cm -3 The thickness is 10nm.

[0056] Example 7 Embodiment 7 of the present invention also proposes a high color gamut LED epitaxial wafer. The difference between the high color gamut LED epitaxial wafer in this embodiment and the high color gamut LED epitaxial wafer in Embodiment 1 is that: The doping concentration of the P-type doped GaN layer is 1×10⁻⁶. 19 cm -3 The thickness is 6nm.

[0057] Example 8 Embodiment 8 of the present invention also proposes a high color gamut LED epitaxial wafer. The difference between the high color gamut LED epitaxial wafer in this embodiment and the high color gamut LED epitaxial wafer in Embodiment 1 is that: The doping concentration of the p-type doped GaN layer is 7 × 10⁻⁶. 19 cm -3 The thickness is 6nm.

[0058] Example 9 Embodiment 9 of the present invention also proposes a high color gamut LED epitaxial wafer. The difference between the high color gamut LED epitaxial wafer in this embodiment and the high color gamut LED epitaxial wafer in Embodiment 1 is that: The doping concentration of the P-type doped GaN layer is 1×10⁻⁶. 20 cm -3 The thickness is 6nm.

[0059] Comparative Example 1 Comparative Example 1 of the present invention also proposes a high color gamut LED epitaxial wafer. The difference between the high color gamut LED epitaxial wafer in this embodiment and the high color gamut LED epitaxial wafer in Example 1 is as follows: No insert layer is added.

[0060] Comparative Example 2 Comparative Example 2 of the present invention also proposes a high color gamut LED epitaxial wafer. The difference between the high color gamut LED epitaxial wafer in this embodiment and the high color gamut LED epitaxial wafer in Example 1 is as follows: The doping concentration of the P-type doped GaN layer is 3 × 10⁻⁶. 19 cm -3 The thickness is 12nm.

[0061] Comparative Example 3 Comparative Example 3 of the present invention also proposes a high color gamut LED epitaxial wafer. The difference between the high color gamut LED epitaxial wafer in this embodiment and the high color gamut LED epitaxial wafer in Example 1 is as follows: The doping concentration of the p-type doped GaN layer is 5 × 10⁻⁶. 18 cm -3 The thickness is 6nm.

[0062] Comparative Example 4 Comparative Example 4 of the present invention also proposes a high color gamut LED epitaxial wafer. The difference between the high color gamut LED epitaxial wafer in this embodiment and the high color gamut LED epitaxial wafer in Example 1 is as follows: The doping concentration of the P-type doped GaN layer is 3 × 10⁻⁶. 20 cm -3 The thickness is 6nm.

[0063] Please refer to Table 1 below, which shows the parameters corresponding to the above embodiments and comparative examples of the present invention.

[0064] Table 1

[0065] It should be noted that the LED chips fabricated in the examples and comparative examples were all prepared as 20mil×40mil chips using the same process conditions. 300 LED chips were randomly selected from each example, and their performance was tested at a current of 150mA. VF4: represents the forward voltage of the LED chip, and PO: represents the luminous power of the LED chip.

[0066] Combining Table 1 and Figure 2 When the thickness of the insertion layer is around 6 nm, the luminous power reaches a relatively high level. If the thickness is too thin or too thick, the luminous power decreases significantly, and the forward voltage also fluctuates. When the thickness is 6 nm, the forward voltage is lower, which is closer to the optimal state of low voltage and high power.

[0067] When the doping concentration of the insertion layer is 3×10 19 cm -3 ~7×10 19 cm -3 When the doping concentration is within the specified range, the luminous power remains at a high level. If the doping concentration is too low or too high, the luminous power decreases significantly, and the forward voltage also increases accordingly.

[0068] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0069] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A high color gamut LED epitaxial wafer, characterized in that, The high color gamut LED epitaxial wafer includes a substrate and an epitaxial layer stacked on the substrate. The epitaxial layer includes a buffer layer, a three-dimensional GaN layer, an undoped GaN layer, an N-type GaN layer, a stress relief layer, a multiple quantum well layer, an electron blocking layer, and a P-type GaN layer stacked sequentially. The multiple quantum well layer includes a green quantum well layer and a blue quantum well layer stacked on top of the green quantum well layer, with an insertion layer between the green quantum well layer and the blue quantum well layer. The insertion layer is a P-type doped GaN layer.

2. The high color gamut LED epitaxial wafer according to claim 1, characterized in that, The blue light multi-quantum well layer consists of periodically alternating InGaN and GaN layers with a period number of 1 to 15. The In content of the InGaN layer is 0.1 to 0.2%, the thickness of the InGaN layer is 2 nm to 4 nm, and the thickness of the GaN layer is 8 nm to 12 nm.

3. The high color gamut LED epitaxial wafer according to claim 1, characterized in that, The green light multi-quantum well layer consists of periodically alternating InGaN and GaN layers with a period number of 1 to 15. The In content of the InGaN layer is 0.2 to 0.3%, the thickness of the InGaN layer is 2 nm to 4 nm, and the thickness of the GaN layer is 8 nm to 12 nm.

4. The high color gamut LED epitaxial wafer according to claim 1, characterized in that, The dopant of the p-type doped GaN layer is magnesium, with a doping concentration of 1×10⁻⁶. 19 cm -3 ~1×10 20 cm -3 .

5. The high color gamut LED epitaxial wafer according to claim 4, characterized in that, The thickness of the P-type doped GaN layer is 2 nm to 10 nm.

6. The high color gamut LED epitaxial wafer according to claim 1, characterized in that, The substrate is a sapphire substrate.

7. The high color gamut LED epitaxial wafer according to claim 1, characterized in that, The buffer layer is a GaN layer with a thickness of 15nm~35nm, the stress relief layer includes periodically alternating InGaN and GaN layers, and the electron blocking layer includes periodically alternating AlGaN and GaN layers.

8. A method for preparing a high color gamut LED epitaxial wafer, characterized in that, The preparation method is used to prepare the high color gamut LED epitaxial wafer according to any one of claims 1 to 7, and the preparation method includes: Provide a substrate; A buffer layer, a three-dimensional GaN layer, an undoped GaN layer, an N-type GaN layer, and a stress relief layer are epitaxially grown sequentially on the substrate. A green light multi-quantum well layer, an insertion layer, and a blue light multi-quantum well layer are epitaxially grown sequentially on the stress relief layer, wherein the insertion layer is a P-type doped GaN layer. An electron blocking layer and a P-type GaN layer are then epitaxially grown on the blue light multi-quantum layer.

9. The method for preparing a high color gamut LED epitaxial wafer according to claim 8, characterized in that, The growth temperature of the P-type doped GaN layer is 800℃~1000℃, and the growth pressure is 100 torr~500 torr.

10. An LED chip, characterized in that, The LED chip includes the high color gamut LED epitaxial wafer as described in any one of claims 1 to 7.

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