Light-emitting diode epitaxial wafer, method for preparing same, and light-emitting diode

Abstract

The present invention discloses a light-emitting diode epitaxial wafer, a preparation method thereof, and a light-emitting diode, relating to the field of semiconductor optoelectronic devices. The epitaxial wafer sequentially includes a substrate, a buffer layer, an undoped GaN layer, an N-type GaN layer, a multi-quantum well layer, an electron blocking layer, and a P-type GaN layer; the multi-quantum well layer is a periodic structure formed by alternately laminating a quantum well layer and a quantum barrier layer; the quantum barrier layer includes an Si3N4 layer, an electric field shielding layer, and an InGaN layer which are sequentially laminated; the electric field shielding layer is a periodic structure with a period number of 1 to 10, and each period includes an intrinsic GaN layer and a C, Si co-doped AlN layer which are sequentially laminated. Implementing the present invention can improve the light-emitting efficiency of the light-emitting diode.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor optoelectronic devices, and particularly to a light-emitting diode epitaxial wafer, a preparation method thereof, and a light-emitting diode. Background Art

[0002] With the vigorous development of the third-generation semiconductor industry and continuous breakthroughs in related technologies, a new type of solid-state lighting industry mainly based on gallium nitride (GaN)-based light-emitting diodes (LEDs) has rapidly emerged globally and become the technological and industrial high ground that various countries compete for. In recent years, countries have carried out technical research on the GaN-based LED lighting industry, successively introduced development plans and corresponding development encouragement policies, etc., making its industry gradually mature. Semiconductor lighting based on GaN-based white LEDs, in addition to features such as long lifespan and small size, its advantages of energy conservation and environmental protection have important strategic significance for the conservation of global resources and the development of society.

[0003] The recombination efficiency of electrons and holes in the active layer is closely related to the luminous efficiency of the light-emitting diode. The active layer includes a quantum well layer and a quantum barrier layer. In order to improve the coupling degree of the wave functions of electrons and holes, reduce the electron overflow into the P-type layer, and improve the uniform distribution of electrons and holes in the active layer, usually the quantum barrier layer uses AlGaN material. However, there is a large polarization effect between the AlGaN quantum barrier layer and the InGaN quantum well layer, resulting in the separation of the wave functions of electrons and holes. The temperature of the deposited multiple quantum well layer is relatively low, and the crystal quality is poor, resulting in defects affecting the crystal quality of other quantum wells, leading to a decrease in the internal quantum efficiency and luminous efficiency of the LED. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a light-emitting diode epitaxial wafer and a preparation method thereof, which can improve the luminous efficiency of the light-emitting diode.

[0005] To solve the above problems, the present invention discloses a light-emitting diode epitaxial wafer, which includes a substrate, a buffer layer, an undoped GaN layer, an N-type GaN layer, a multiple quantum well layer, an electron blocking layer, and a P-type GaN layer that are sequentially stacked on the substrate; the multiple quantum well layer is a periodic structure formed by alternately stacking a quantum well layer and a quantum barrier layer;

[0006] The quantum barrier layer includes a Si3N4 layer, an electric field shielding layer, and an InGaN layer that are sequentially stacked; the electric field shielding layer is a periodic structure, the number of periods is 1 to 10, and each period includes an intrinsic GaN layer and a C, Si co-doped AlN layer that are sequentially stacked.

[0007] As an improvement of the above technical solution, the number of periods of the electric field shielding layer is 3 to 10, and the thickness of the intrinsic GaN layer is 1 nm to 10 nm;

[0008] The thickness of the C, Si co-doped AlN layer is 0.5 nm to 5 nm, and its C doping concentration is 1×10 16 cm -3 ~1×10 17 cm -3 , and its Si doping concentration is 1×10 17 cm -3 ~1×10 18 cm -3 .

[0009] As an improvement of the above technical solution, the thickness of the Si3N4 layer is 0.5 nm to 5 nm;

[0010] The thickness of the InGaN layer is 0.5 nm to 5 nm, and the In component ratio is 0.01 to 0.2.

[0011] As an improvement of the above technical solution, the quantum well layer is an In x Ga 1-x N layer, x is 0.15 to 0.3, and its thickness is 1 nm to 5 nm.

[0012] As an improvement of the above technical solution, along the growth direction of the epitaxial wafer, the In component in the InGaN layer shows an increasing change.

[0013] Correspondingly, the present invention also discloses a method for preparing a light-emitting diode epitaxial wafer for preparing the above-mentioned light-emitting diode epitaxial wafer, which includes:

[0014] Providing a substrate, and sequentially growing a buffer layer, an undoped GaN layer, an N-type GaN layer, a multi-quantum well layer, an electron blocking layer, and a P-type GaN layer on the substrate; the multi-quantum well layer is a periodic structure formed by alternately stacking a quantum well layer and a quantum barrier layer;

[0015] The quantum barrier layer includes a Si3N4 layer, an electric field shielding layer, and an InGaN layer stacked in sequence; the electric field shielding layer is a periodic structure, the number of periods is 1 to 10, and each period includes an intrinsic GaN layer and a C, Si co-doped AlN layer stacked in sequence.

[0016] As an improvement of the above technical solution, the growth temperature of the Si3N4 layer is 800 °C to 900 °C, the growth pressure is 50 torr to 500 torr, its growth atmosphere is a mixed gas of N2 and NH3, and the volume ratio of N2 to NH3 is 5:1 to 10:1.

[0017] As an improvement of the above technical solution, the growth temperature of the intrinsic GaN layer is 800 °C to 1000 °C, the growth pressure is 50 torr to 500 torr, the growth atmosphere thereof is a mixed gas of N2, NH3 and H2, and the volume ratio of N2, NH3 and H2 is 1:1:1 to 1:10:5;

[0018] The growth temperature of the C, Si co-doped AlN layer is 800 °C to 1000 °C, the growth pressure is 50 torr to 500 torr, the growth atmosphere thereof is a mixed gas of N2, NH3 and H2, and the volume ratio of N2, NH3 and H2 is 1:1:1 to 1:5:10.

[0019] As an improvement of the above technical solution, the growth temperature of the InGaN layer is 800 °C to 1000 °C, the growth pressure is 50 torr to 300 torr, the growth atmosphere thereof is a mixed gas of N2 and NH3, and the volume ratio of N2 and NH3 is 5:1 to 10:1.

[0020] Correspondingly, the present invention also discloses a light-emitting diode, which comprises the above-mentioned light-emitting diode epitaxial wafer.

[0021] Implementing the present invention has the following beneficial effects:

[0022] In the light-emitting diode epitaxial wafer of the present invention, the quantum barrier layer comprises a Si3N4 layer, an electric field shielding layer and an InGaN layer which are stacked in sequence; the electric field shielding layer is a periodic structure, the number of periods is 1 to 10, and each period comprises an intrinsic GaN layer and a C, Si co-doped AlN layer which are stacked in sequence. Among them, the Si3N4 layer can reduce the diffusion of InGaN in the quantum well layer to the barrier layer, improve the quantum confinement effect of the quantum well layer. In addition, the Si3N4 layer reduces the defect extension and improves the crystal quality. The periodic structure formed by the intrinsic GaN layer and the C, Si co-doped AlN layer has a high potential barrier, which reduces the electron overflow to the P-type GaN layer and improves the light-emitting efficiency. Second, the C, Si co-doped AlN layer can shield the epitaxial layer defects, improve the crystal quality, and can also regulate the C-Si doping concentration to shield the piezoelectric field effect in the quantum well. Third, the electric field shielding layer can also regulate the injection depth of holes, improve the uniformity of carriers in the active region, improve the wave function overlap of electrons and holes, and improve the light-emitting efficiency of the light-emitting diode. The InGaN layer can buffer the lattice mismatch between the quantum barrier layer and the quantum well layer, improve the crystal quality of the multi-quantum well layer, increase the radiative recombination probability of electrons and holes, and improve the light-emitting efficiency of the light-emitting diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of a light-emitting diode epitaxial wafer in an embodiment of the present invention;

[0024] Figure 2It is a schematic structural diagram of a multi - quantum well layer in an embodiment of the present invention;

[0025] Figure 3 It is a flowchart of a method for preparing a light - emitting diode epitaxial wafer in an embodiment of the present invention. Detailed implementation manners

[0026] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below.

[0027] Referring to Figure 1 and Figure 2 , the present invention discloses a light - emitting diode epitaxial wafer, which includes a substrate 100, a buffer layer 200, an undoped GaN layer 300, an N - type GaN layer 400, a multi - quantum well layer 500, an electron blocking layer 600, and a P - type GaN layer 700 that are sequentially stacked on the substrate 100. Among them, the multi - quantum well layer is a periodic structure, and the number of periods is 3 - 15. Each period of the multi - quantum well layer 500 includes a quantum well layer and a quantum barrier layer stacked in sequence. The quantum well layer is an In x Ga 1-x N layer 510, and the In component ratio (i.e., x) is 0.15 - 0.4, and exemplarily 0.17, 0.19, 0.21, 0.24, 0.27, 0.31, 0.35 or 0.38, but not limited thereto. Preferably, x is 0.15 - 0.3. The thickness of the quantum well layer is 1 nm - 5 nm, and exemplarily 2 nm, 2.4 nm, 2.8 nm, 3 nm, 3.4 nm, 3.9 nm, 4 nm or 4.5 nm, but not limited thereto. Preferably, it is 1 nm - 5 nm, and more preferably 2.5 nm - 4 nm.

[0028] Among them, the quantum barrier layer includes a Si3N4 layer 520, an electric field shielding layer 530, and an InGaN layer 540 that are sequentially stacked on the quantum well layer; among them, the thickness of the Si3N4 layer 520 is 0.5 nm - 5 nm, and exemplarily 0.8 nm, 1.2 nm, 1.6 nm, 2 nm, 2.3 nm, 3 nm, 4 nm or 4.5 nm, but not limited thereto. Preferably, it is 0.5 nm - 2 nm, and more preferably 0.5 nm - 1.5 nm.

[0029] The electric field shielding layer 530 is a periodic structure with a period number of 1 to 10, exemplarily 2, 4, 6, 8 or 9, and preferably 3 to 10. Each period of the electric field shielding layer 530 includes an intrinsic GaN layer 531 and a C, Si co-doped AlN layer 532 stacked in sequence. The thickness of the intrinsic GaN layer 531 is 0.5nm to 10nm, exemplarily 0.8nm, 1.2nm, 1.4nm, 2nm, 4nm, 6nm or 8nm, preferably 1nm to 10nm, and more preferably 1nm to 2nm. The thickness of the C, Si co-doped AlN layer 532 is 0.5nm to 5nm, exemplarily 0.8nm, 1.2nm, 1.6nm, 2nm, 3nm or 4nm, but not limited thereto. Preferably 0.5nm to 2nm, more preferably 1nm to 2nm. The C doping concentration in the C, Si co-doped AlN layer 532 is 1×10 16 cm -3 ~5×10 17 cm -3 , exemplarily 3×10 16 cm -3 , 5×10 16 cm -3 ,7×10 16 cm -3 , 1×10 17 cm -3 or 3×10 17 cm -3 , but not limited thereto. Preferably 1×10 16 cm -3 ~1×10 17 cm -3 , more preferably 3×10 16 cm -3 ~8×10 16 cm -3 C. The Si doping concentration in the Si co-doped AlN layer 532 is 1×10 17 cm -3 ~3×10 18 cm -3 , exemplarily 3×10 17 cm -3 , 5×10 17 cm -3 ,7×10 17 cm -3 ,9×10 17 cm -3 or 1×10 18 cm -3 , but not limited thereto. Preferably 1×10 17 cm -3 ~1×10 18cm -3 , more preferably 5×10 17 cm -3 ~1×10 18 cm -3 。

[0030] Among them, the thickness of the InGaN layer 540 is 0.5 nm to 5 nm, and exemplary values are 0.8 nm, 1.3 nm, 1.8 nm, 2.2 nm, 3 nm, or 4 nm, but not limited thereto. Preferably, it is 0.5 nm to 2 nm. The In component ratio in the InGaN layer 540 is 0.01 to 0.2, and exemplary values are 0.04, 0.06, 0.09, 0.12, 0.14, or 0.17, but not limited thereto. Preferably, it is 0.05 to 0.15.

[0031] Preferably, in an embodiment of the present invention, along the growth direction of the epitaxial wafer, the In component in the InGaN layer 540 shows an increasing change. Based on this control, the lattice mismatch between the quantum well layer and the quantum barrier layer can be further weakened, and the light emission efficiency can be improved.

[0032] Among them, the substrate 100 is a sapphire substrate, a silicon substrate, or a carbonized substrate, but not limited thereto.

[0033] Among them, the buffer layer 200 is an AlN layer or an AlGaN layer, but not limited thereto. Preferably, it is an AlN layer. The thickness of the buffer layer 200 is 20 nm to 80 nm.

[0034] Among them, the thickness of the undoped GaN layer 300 is 1 μm to 5 μm. The thickness of the N-type GaN layer 400 is 2 μm to 3 μm, and its Si doping concentration is 5×10 18 cm -3 ~5×10 19 cm -3 。

[0035] Among them, the electron blocking layer 600 is an AlGaN layer or an AlInGaN layer, but not limited thereto. Preferably, in an embodiment of the present invention, the electron blocking layer 600 is an AlInGaN layer, its Al component ratio is 0.05 to 0.1, its In component ratio is 0.01 to 0.2, and its thickness is 10 nm to 40 nm. This electron blocking layer can better cooperate with the quantum barrier layer in the present invention to prevent the decrease in light emission efficiency caused by electron overflow.

[0036] Among them, the thickness of the P-type GaN layer 700 is 100 nm to 500 nm, and its Mg doping concentration is 1×10 19 cm -3 ~1×10 21 cm -3 。

[0037] Correspondingly, referring to Figure 3 , the present invention also provides a method for preparing a light-emitting diode epitaxial wafer for preparing the above-mentioned light-emitting diode epitaxial wafer, which specifically includes the following steps:

[0038] S1: Provide a substrate;

[0039] S2: Sequentially grow a buffer layer, an undoped GaN layer, an N-type GaN layer, a multi-quantum well layer, an electron blocking layer, and a P-type GaN layer on the substrate;

[0040] Preferably, in some embodiments of the present invention, step S2 includes:

[0041] S21: Grow a buffer layer on the substrate;

[0042] Among them, in one embodiment of the present invention, an AlN layer is grown by PVD as the buffer layer.

[0043] S22: Grow an undoped GaN layer on the buffer layer;

[0044] Among them, in one embodiment of the present invention, the undoped GaN layer is grown by MOCVD. Its growth temperature is 1050°C to 1200°C, and the growth pressure is 100 torr to 500 torr.

[0045] S23: Grow an N-type GaN layer on the undoped GaN layer;

[0046] Among them, in one embodiment of the present invention, the N-type GaN layer is grown by MOCVD, and its growth temperature is 1050°C to 1200°C, and the growth pressure is 100 torr to 500 torr.

[0047] S24: Grow a multi-quantum well layer on the N-type GaN layer;

[0048] Among them, in one embodiment of the present invention, the quantum well layer and the quantum barrier layer are periodically grown on the N-type GaN layer by MOCVD until a multi-quantum well layer is obtained. Among them, the growth temperature of the quantum well layer is 750°C to 820°C, and the growth pressure is 100 torr to 300 torr.

[0049] The preparation method of each quantum barrier layer is as follows:

[0050] (i) Grow an Si3N4 layer;

[0051] Among them, the growth temperature is 800°C to 900°C, the growth pressure is 50 torr to 500 torr, and the growth atmosphere is a mixed gas of N2 and NH3, and the volume ratio of N2 to NH3 is 5:1 to 10:1.

[0052] (ii) Grow an electric field shielding layer on the Si3N4 layer;

[0053] Among them, an intrinsic GaN layer and a C, Si co-doped AlN layer are grown periodically until an electric field shielding layer is obtained. Specifically, the growth temperature of the intrinsic GaN layer is 800 °C to 1000 °C, the growth pressure is 50 torr to 500 torr, and its growth atmosphere is a mixed gas of N2, NH3 and H2, and the volume ratio of N2, NH3 and H2 is 1:1:1 to 1:10:5; the growth temperature of the C, Si co-doped AlN layer is 800 °C to 1000 °C, the growth pressure is 50 torr to 500 torr, and its growth atmosphere is a mixed gas of N2, NH3 and H2, and the volume ratio of N2, NH3 and H2 is 1:1:1 to 1:10:5.

[0054] (iii) Grow an InGaN layer on the electric field shielding layer;

[0055] Among them, the growth temperature of the InGaN layer is 800 °C to 1000 °C, the growth pressure is 50 torr to 300 torr, and its growth atmosphere is a mixed gas of N2 and NH3, and the volume ratio of N2 and NH3 is 5:1 to 10:1.

[0056] S25: Grow an electron blocking layer on the multi-quantum well layer;

[0057] Among them, in one embodiment of the present invention, an AlInGaN layer is grown by MOCVD as the electron blocking layer, and its growth temperature is 880 °C to 980 °C, and the growth pressure is 100 torr to 300 torr.

[0058] S26: Grow a P-type GaN layer on the electron blocking layer;

[0059] Specifically, in one embodiment of the present invention, a P-type GaN layer is grown by MOCVD, and its growth temperature is 900 °C to 1050 °C, and the growth pressure is 100 torr to 500 torr.

[0060] The present invention will be further described below with specific examples:

[0061] Example 1

[0062] Reference Figure 1 and Figure 2 , this embodiment provides a light-emitting diode epitaxial wafer, which includes a substrate 100, a buffer layer 200, an undoped GaN layer 300, an N-type GaN layer 400, a multi-quantum well layer 500, an electron blocking layer 600, and a P-type GaN layer 700 that are sequentially stacked on the substrate 100.

[0063] Among them, the substrate 100 is a sapphire substrate, the buffer layer 200 is an AlN layer with a thickness of 25 nm. The thickness of the undoped GaN layer 300 is 2.5 μm. The doping concentration of the N-type GaN layer 400 is 1.2×10 19 cm -3 , and its thickness is 2.8 μm.

[0064] Among them, the multiple quantum well layer 500 is a periodic structure formed by alternately stacking quantum well layers and quantum barrier layers, with a period number of 10. Among them, the quantum well layer is In x Ga 1-x N layer 510 (x = 0.25) with a thickness of 3 nm. The quantum barrier layer includes a Si3N4 layer 520, an electric field shielding layer 530, and an InGaN layer 540 stacked in sequence; among them, the thickness of the Si3N4 layer 520 is 3 nm, the electric field shielding layer 530 is a periodic structure with a period number of 4, the thickness of the intrinsic GaN layer 531 is 4 nm, and the thickness of the C, Si co-doped AlN layer 532 is 4 nm. The C doping concentration in the C, Si co-doped AlN layer 532 is 4×10 17 cm -3 , and the Si doping concentration is 2×10 18 cm -3 . The thickness of the InGaN layer 540 is 3.5 nm, the In component ratio is 0.18, and the In component is constant.

[0065] Among them, the electron blocking layer 600 is an AlInGaN layer with an Al component ratio of 0.08, an In component ratio of 0.11, and a thickness of 25 nm. The Mg doping concentration in the P-type GaN layer 700 is 5×10 20 cm -3 , and the thickness is 250 nm.

[0066] In this embodiment, the method for preparing the light-emitting diode epitaxial wafer includes the following steps:

[0067] (1) Provide a substrate.

[0068] (2) Grow a buffer layer on the substrate;

[0069] Among them, grow an AlN layer by PVD as the buffer layer;

[0070] (3) Grow an undoped GaN layer on the buffer layer;

[0071] Among them, grow the undoped GaN layer by MOCVD. Its growth temperature is 1100 °C and the growth pressure is 150 torr.

[0072] (4) Grow an N-type GaN layer on the undoped GaN layer;

[0073] Among them, an N-type GaN layer is grown by MOCVD, with a growth temperature of 1120 °C and a growth pressure of 100 torr.

[0074] (5) Grow a multi-quantum well layer on the N-type semiconductor layer;

[0075] Among them, a quantum well layer and a quantum barrier layer are periodically grown on the N-type GaN layer by MOCVD until a multi-quantum well layer is obtained. Among them, the growth temperature of the quantum well layer is 760 °C and the growth pressure is 200 torr.

[0076] Among them, the preparation method of each quantum barrier layer includes:

[0077] (i) Grow a Si3N4 layer;

[0078] Among them, the growth temperature is 880 °C, the growth pressure is 200 torr, and the growth atmosphere is a mixed gas of N2 and NH3, and the volume ratio of N2 to NH3 is 7:1.

[0079] (ii) Grow an electric field shielding layer on the Si3N4 layer;

[0080] Among them, an intrinsic GaN layer and a C, Si co-doped AlN layer are periodically grown until an electric field shielding layer is obtained. Specifically, the growth temperature of the intrinsic GaN layer is 950 °C, the growth pressure is 200 torr, and the growth atmosphere is a mixed gas of N2, NH3 and H2, and the volume ratio of N2, NH3 and H2 is 1:7:3; the growth temperature of the C, Si co-doped AlN layer is 970 °C, the growth pressure is 200 torr, and the growth atmosphere is a mixed gas of N2, NH3 and H2, and the volume ratio of N2, NH3 and H2 is 1:7:3.

[0081] (iii) Grow an InGaN layer on the electric field shielding layer;

[0082] Among them, the growth temperature is 820 °C, the growth pressure is 200 torr, and the growth atmosphere is a mixed gas of N2 and NH3, and the volume ratio of N2 to NH3 is 6:1.

[0083] (6) Grow an electron blocking layer on the multi-quantum well layer;

[0084] Among them, an AlInGaN layer is grown by MOCVD as the electron blocking layer, with a growth temperature of 920 °C and a growth pressure of 150 torr.

[0085] (7) Grow a P-type GaN layer on the electron blocking layer;

[0086] Specifically, a P-type GaN layer is grown by MOCVD, with a growth temperature of 1030 °C and a growth pressure of 300 torr.

[0087] Example 2

[0088] This example provides a light - emitting diode epitaxial wafer, and the difference from Example 1 is as follows:

[0089] The thickness of the Si3N4 layer 520 is 1.2 nm, the thickness of the intrinsic GaN layer 531 is 1.2 nm, the thickness of the C, Si co - doped AlN layer 532 is 1.5 nm, the C doping concentration in the C, Si co - doped AlN layer 532 is 5×10 16 cm -3 , and the Si doping concentration is 7×10 17 cm -3 . The thickness of the InGaN layer 540 is 1.5 nm, and the In component ratio is 0.08.

[0090] The rest are the same as those in Example 1.

[0091] Example 3

[0092] This example provides a light - emitting diode epitaxial wafer, and the difference from Example 3 is as follows:

[0093] The average In component ratio in the InGaN layer 540 is 0.1 and shows an increasing change along the epitaxial growth direction.

[0094] The rest are the same as those in Example 2.

[0095] Comparative Example 1

[0096] This comparative example provides a light - emitting diode epitaxial wafer, and the difference from Example 1 is as follows:

[0097] The quantum barrier layer is a GaN layer with a thickness of 10 nm, a growth temperature of 860 °C, and a growth pressure of 200 torr.

[0098] The rest are the same as those in Example 1.

[0099] Comparative Example 2

[0100] This comparative example provides a light - emitting diode epitaxial wafer, and the difference from Example 1 is as follows:

[0101] The quantum barrier layer does not include the Si3N4 layer. Correspondingly, the preparation method does not include the preparation step of this layer.

[0102] The rest are the same as those in Example 1.

[0103] Comparative Example 3

[0104] This comparative example provides a light - emitting diode epitaxial wafer, and the difference from Example 1 is as follows:

[0105] The quantum barrier layer does not include an electric field shielding layer. Correspondingly, the manufacturing method does not include the manufacturing step of this layer either.

[0106] The rest are the same as in Example 1.

[0107] Comparative Example 4

[0108] This comparative example provides a light-emitting diode epitaxial wafer, and the difference from Example 1 is that:

[0109] The quantum barrier layer does not include an InGaN layer. Correspondingly, the manufacturing method does not include the manufacturing step of this layer either.

[0110] The rest are the same as in Example 1.

[0111] Test the light-emitting diode epitaxial wafers obtained in Examples 1 to 4 and Comparative Example 1, and calculate the light emission efficiency improvement rate based on the data of Comparative Example 1.

[0112] The specific results are shown in the following table:

[0113] Luminous efficiency improvement rate / % Example 1 4.32 Example 2 5.54 Example 3 5.73 Comparative Example 1 - Comparative Example 2 1.5 Comparative Example 3 0.5 Comparative Example 4 1

[0114] The above are the preferred embodiments of the invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements are also regarded as the protection scope of the present invention.

Claims

1. A light-emitting diode epitaxial wafer, characterized in that, It includes a substrate, a buffer layer, an undoped GaN layer, an N-type GaN layer, a multi-quantum well layer, an electron blocking layer, and a P-type GaN layer that are sequentially stacked on the substrate; the multi-quantum well layer is a periodic structure formed by alternately stacking quantum well layers and quantum barrier layers. The quantum barrier layer includes a Si3N4 layer, an electric field shielding layer, and an InGaN layer that are sequentially stacked; the electric field shielding layer is a periodic structure with a period number of 1 to 10, and each period includes an intrinsic GaN layer and a C, Si co-doped AlN layer that are sequentially stacked.

2. The light-emitting diode epitaxial wafer according to claim 1, characterized in that, The period number of the electric field shielding layer is 3 to 10, and the thickness of the intrinsic GaN layer is 1 nm to 10 nm. The thickness of the C, Si co-doped AlN layer is 0.5 nm to 5 nm, and its C doping concentration is 1×10 16 cm -3 ~1×10 17 cm -3 ,and the Si doping concentration is 1×10 17 cm -3 ~1×10 18 cm -3 。 3. The light-emitting diode epitaxial wafer according to claim 1, wherein The thickness of the Si3N4 layer is 0.5 nm to 5 nm. The thickness of the InGaN layer is 0.5 nm to 5 nm, and the In component ratio is 0.01 to 0.

2.

4. The light-emitting diode epitaxial wafer according to any one of claims 1 to 3, characterized in that, The quantum well layer is an In x Ga 1-x N layer, where x is 0.15 to 0.3 and its thickness is 1 nm to 5 nm.

5. The light-emitting diode epitaxial wafer according to claim 4, wherein, Along the growth direction of the epitaxial wafer, the In component in the InGaN layer shows an increasing change.

6. A method for preparing a light-emitting diode epitaxial wafer, which is used to prepare the light-emitting diode epitaxial wafer according to any one of claims 1 to 5, characterized in that, It includes: Providing a substrate, and sequentially growing a buffer layer, an undoped GaN layer, an N-type GaN layer, a multi-quantum well layer, an electron blocking layer, and a P-type GaN layer on the substrate; the multi-quantum well layer is a periodic structure formed by alternately stacking quantum well layers and quantum barrier layers. The quantum barrier layer includes a Si3N4 layer, an electric field shielding layer, and an InGaN layer that are sequentially stacked; the electric field shielding layer is a periodic structure with a period number of 1 to 10, and each period includes an intrinsic GaN layer and a C, Si co-doped AlN layer that are sequentially stacked.

7. The method for preparing a light-emitting diode epitaxial wafer according to claim 6, wherein, The growth temperature of the Si3N4 layer is 800 °C to 900 °C, the growth pressure is 50 torr to 500 torr, its growth atmosphere is a mixed gas of N2 and NH3, and the volume ratio of N2 to NH3 is 5:1 to 10:

1.

8. The method for preparing a light-emitting diode epitaxial wafer according to claim 6, wherein, The growth temperature of the intrinsic GaN layer is 800 °C to 1000 °C, the growth pressure is 50 torr to 500 torr, its growth atmosphere is a mixed gas of N2, NH3, and H2, and the volume ratio of N2, NH3, and H2 is 1:1:1 to 1:10:

5. The growth temperature of the C, Si co-doped AlN layer is 800 °C to 1000 °C, the growth pressure is 50 torr to 500 torr, its growth atmosphere is a mixed gas of N2, NH3, and H2, and the volume ratio of N2, NH3, and H2 is 1:1:1 to 1:10:

5.

9. The method for preparing a light-emitting diode epitaxial wafer according to claim 6, wherein, The growth temperature of the InGaN layer is 800 °C to 1000 °C, the growth pressure is 50 torr to 300 torr, its growth atmosphere is a mixed gas of N2 and NH3, and the volume ratio of N2 to NH3 is 5:1 to 10:

1.

10. A light-emitting diode, characterized in that, It includes the light-emitting diode epitaxial wafer according to any one of claims 1 to 5.

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