High-brightness light emitting diode epitaxial structure and preparation method thereof, LED

Abstract

This invention discloses a high-brightness light-emitting diode epitaxial structure and its fabrication method, relating to the field of semiconductor optoelectronic devices. The high-brightness light-emitting diode epitaxial structure includes a substrate, and sequentially stacked layers of a buffer layer, an undoped GaN layer, an N-GaN layer, an active layer, a barrier layer, a first P-GaN layer, a shunt layer, a second P-GaN layer, and a contact layer; wherein the barrier layer is Mg-doped Al. x Ga 1‑x N layer; the shunt layer consists of sequentially stacked AlN layers and Mg-doped Al layers. y Ga 1‑ y N-layer, contact layer is Mg-doped Al z Ga 1‑z N-layer, Mg-doped Al x Ga 1‑x N-layer, Mg-doped Al y Ga 1‑y N-layer, Mg-doped Al z Ga 1‑z Multiple Al quantum dots are formed in each of the N layers to create multi-layered light-harvesting channels. Implementing this invention can improve the brightness of the LED epitaxial structure without increasing the operating voltage.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor optoelectronic devices, in particular to a high-brightness LED epitaxial structure and a preparation method thereof. BACKGROUND

[0002] LED is the latest lighting and display product, which is gradually rising in the industry. Whether it is backlight or commercial lighting application, it has an unparalleled place. Especially in the new generation of backlight products, due to the characteristics of lightness, thinness, smallness and power saving, it has become the first choice for the new generation of backlights. The current backlight products are mainly based on GaN LED, and the P-type GaN layer on the surface needs to be doped with Mg. Due to the low ionization efficiency of Mg, less Mg can be utilized, and the Mg that is not fully utilized will form light absorption defects and form phonon scattering, thereby reducing the light extraction efficiency and the light efficiency. This is a problem that needs to be solved. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a high-brightness LED epitaxial structure and a preparation method thereof, which can improve the light efficiency of the LED epitaxial structure.

[0004] The technical problem to be solved by the present application is to provide a high-brightness LED.

[0005] In order to solve the above problems, the present application discloses a high-brightness LED epitaxial structure, which comprises a substrate, a buffer layer, an undoped GaN layer, an N-GaN layer, an active layer, a barrier layer, a first P-GaN layer, a shunt layer, a second P-GaN layer and a contact layer which are sequentially stacked on the substrate.

[0006] The barrier layer is a Mg-doped Al x Ga 1-x N layer, and x is 0.1-0.3; the shunt layer comprises an AlN layer and a Mg-doped Al y Ga 1-y N layer which are sequentially stacked on the first P-GaN layer, and y is 0.15-0.35; the contact layer is a Mg-doped Al z Ga 1- z N layer, and z is 0.1-0.2.

[0007] The Mg-doped Al x Ga 1-x N layer, the Mg-doped Al y Ga 1-y N layer and the Mg-doped Al z Ga 1-z N layer all form a plurality of Al quantum dots to form a multi-level light channel.

[0008] As the improvement of the above technical solution, the Mg-doped Al x Ga 1-x N layer has a Mg doping concentration of 5×10 17 cm -3 ~8×10 18 cm -3 , and a thickness of

[0009] As the improvement of the above technical solution, the Mg-doped Al y Ga 1-y N layer has a Mg doping concentration of 1×10 18 cm -3 ~9×10 18 cm -3 , and a thickness of The thickness of the AlN layer is

[0010] As the improvement of the above technical solution, the Mg-doped Al z Ga 1-z N layer has a Mg doping concentration of 5×10 19 cm -3 ~2×10 20 cm -3 , and a thickness of

[0011] Correspondingly, the application also discloses a preparation method of the high-brightness LED epitaxial structure.

[0012] A substrate is provided, and a buffer layer, an undoped GaN layer, an N-GaN layer, an active layer, a barrier layer, a first P-GaN layer, a shunt layer, a second P-GaN layer and a contact layer are sequentially grown on the substrate.

[0013] The barrier layer is a Mg-doped Al x Ga 1-x N layer, and x is 0.1-0.3; the shunt layer comprises an AlN layer and a Mg-doped Al y Ga 1-y N layer which are sequentially stacked on the first P-GaN layer, and y is 0.15-0.35; and the contact layer is a Mg-doped Al z Ga 1- z N layer, and z is 0.1-0.2.

[0014] The Mg-doped Al x Ga 1-x N layer, the Mg-doped Al y Ga 1-y N layer and the Mg-doped Alz Ga 1-z The growth speed of the N layer is ≤0.1 μm / h, and the growth is stopped for 10-30 min after the growth is completed, so as to form a plurality of Al quantum dots in the Mg-doped Al x Ga 1-x N layer, Mg-doped Al y Ga 1-y N layer, Mg-doped Al z Ga 1-z N layer.

[0015] As an improvement of the above technical solution, the growth temperature of the barrier layer is 800-850 ℃, the growth pressure is 150-200 torr, and the growth atmosphere is a mixed gas of N2 and NH3, and the volume ratio of the two is (1-3):1.

[0016] As an improvement of the above technical solution, the growth temperature of the barrier layer is 800-850 ℃, the growth pressure is 150-200 torr, and the growth atmosphere is a mixed gas of N2 and NH3, and the volume ratio of the two is (1-3):1.

[0017] As an improvement of the above technical solution, the growth temperature of the barrier layer is 800-850 ℃, the growth pressure is 150-200 torr, and the growth atmosphere is a mixed gas of N2 and NH3, and the volume ratio of the two is (1-3):1.

[0018] Correspondingly, the application also discloses a high-brightness LED comprising the high-brightness LED epitaxial structure.

[0019] The application has the following beneficial effects:

[0020] The high-brightness LED epitaxial structure comprises a substrate, a buffer layer, an undoped GaN layer, an N-GaN layer, an active layer, a barrier layer, a first P-GaN layer, a shunt layer, a second P-GaN layer and a contact layer which are sequentially stacked on the substrate; a plurality of Al quantum dots are formed in the barrier layer, the shunt layer and the contact layer, which have a shock transmission effect on visible light and reduce the absorption of light. Since the Al quantum dots are located in different layers, a multi-layer stacked structure is formed, so that light can be captured in the position with high refractive index and will not be absorbed by islocation, a light extraction channel is formed, the light extraction efficiency is improved, and the brightness is improved. In addition, the use of Mg-doped AlGaN material will not greatly increase the working voltage of the LED epitaxial structure.

[0021] Further, the shunt layer between the first P-GaN layer and the second P-GaN layer is an AlN layer and an Mg-doped Al y Ga 1-y N layer, which has a high energy level and is beneficial to uniform distribution of current; the Mg-doped Al y Ga 1-y N layer also forms a two-dimensional electron gas (2DEG) with the second P-GaN layer, further optimizes the lateral distribution of current, reduces the generation of droop effect, and improves light efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a structural schematic diagram of an epitaxial structure of a high-brightness light-emitting diode according to an embodiment of the present application;

[0023] Figure 2 is a structural schematic diagram of a shunt layer according to an embodiment of the present application;

[0024] Figure 3 is a flowchart of a preparation method of an epitaxial structure of a high-brightness light-emitting diode according to an embodiment of the present application. DETAILED DESCRIPTION

[0025] To make the purpose, technical solutions and advantages of the present application clearer, the present application is described in further detail below.

[0026] Reference Figure 1 and Figure 2 The present application discloses an epitaxial structure of a high-brightness light-emitting diode, which comprises a substrate 1, a buffer layer 2, an undoped GaN layer 3, an N-GaN layer 4, an active layer 5, a barrier layer 6, a first P-GaN layer 7, a shunt layer 8, a second P-GaN layer 9 and a contact layer 10 which are sequentially stacked on the substrate 1; wherein the barrier layer 6 is an Mg-doped Al x Ga 1-x N layer (x=0.1-0.3); the shunt layer 8 comprises an AlN layer 81 and an Mg-doped Al y Ga 1-y N layer 82 (y=0.15-0.35) which are sequentially stacked on the first P-GaN layer 7; and the contact layer 10 is an Mg-doped Al z Ga 1-z N layer (z=0.1-0.2); the Mg-doped Al x Ga 1-x N layer, the Mg-doped Al y Ga 1-y N layer 82, the Mg-doped Al z Ga 1-zA plurality of Al quantum dots are formed in the N layer to form a multi-level light extraction channel and improve light extraction efficiency. It should be noted that the semiconductor layer of AlGaN material has a high refractive index and is easy to concentrate light. After the Al quantum dots are added, the light concentration effect is further enhanced. After the light is concentrated, the light is easy to be totally reflected when entering the defect with a low refractive index, unlike the traditional P-type GaN layer, in which the light is absorbed by the defect and converted into heat radiation, so that the light extraction efficiency is effectively improved.

[0027] Preferably, in an embodiment of the present application, y > x > z is controlled to form a Mg-doped Al x Ga 1-x N layer, a Mg-doped Al y Ga 1-y N layer 82, a Mg-doped Al z Ga 1-z N layer, and the Al quantum dots are formed in the N layer to further improve the light extraction efficiency.

[0028] The barrier layer 6 not only provides Al quantum dots to improve light extraction efficiency, but also effectively blocks electrons from the active layer 6 into the first P-GaN layer 7, consumes holes, forms non-radiative recombination, and reduces light efficiency. Specifically, the Mg-doped Al x Ga 1-x N layer) has a Mg doping concentration of 5×10 17 cm -3 ~ 8×10 18 cm -3 , and exemplary values are 7×10 17 cm -3 , 9×10 17 cm -3 , 1×10 18 cm -3 , 3×10 18 cm -3 , 5×10 18 cm -3 or 7×10 18 cm -3 , but not limited to these values. The thickness of the barrier layer 6 is exemplary values are or but not limited to these values.

[0029] The AlN layer 81 in the shunt layer 8 has a higher potential barrier, which is beneficial to the uniform distribution of current and reduces the generation of droop effect and improves light efficiency. At the same time, the AlN layer 81 promotes the Mg-doped Al y Ga 1-yThe uniform distribution of Al component in the N layer 82, and further the uniform distribution of Al quantum dots after post-processing, promotes the light extraction efficiency. The Mg-doped Al y Ga 1-y N layer 82 forms a two-dimensional electron gas (2DEG) with the second P-GaN layer, further optimizes the lateral distribution of current, reduces the generation of droop effect, and improves the light efficiency. Specifically, the thickness of the AlN layer 81 is Exemplarily, the thickness of the AlN layer 81 is or but not limited to this. The Mg-doped Al y Ga 1-y N layer 82 has a Mg doping concentration of 1 x 10 18 cm -3 ~ 9 x 10 18 cm -3 Exemplarily, the Mg doping concentration of the AlN layer 82 is 3 x 10 18 cm -3 , 5 x 10 18 cm -3 , 7 x 10 18 cm -3 or 8 x 10 18 cm -3 but not limited to this. The Mg-doped Al y Ga 1-y N layer 82 has a thickness of Exemplarily, the thickness of the AlN layer 81 is or but not limited to this.

[0030] The contact layer 10 not only provides Al quantum dots to improve the light extraction efficiency, but also forms a two-dimensional electron gas (2DEG) with the second P-GaN layer 8, further optimizes the lateral distribution of current, reduces the generation of droop effect, and improves the light efficiency. Specifically, the Mg-doped Al z Ga 1-z N layer in the contact layer 10 has a Mg doping concentration of 5 x 10 19 cm -3 ~ 2 x 10 20 cm -3 Exemplarily, the Mg doping concentration of the AlN layer 82 is 6 x 10 19 cm -3 , 8 x 10 19 cm -3 , 9 x 10 19 cm -3 , 1 x 10 20 cm -3 or 1.5 x 10 20 cm -3but not limited to. The thickness of the contact layer 10 is An example is or but not limited to.

[0031] The substrate 1 is a sapphire substrate, a substrate, a gallium oxide substrate, a zinc oxide substrate, or a carbonized substrate, but not limited to.

[0032] The buffer layer 2 is an AlN layer or an AlGaN layer, but not limited to. Preferably, the buffer layer 2 is an AlN layer. The thickness of the buffer layer 2 is 30 nm to 80 nm.

[0033] The thickness of the undoped GaN layer 3 is 1 μm to 3 μm.

[0034] The N-type doping element of the N-GaN layer 4 is Si or Ge, but not limited to. Preferably, the N-type doping element of the N-GaN layer 4 is Si. The N-type doping concentration of the N-GaN layer 4 is 5 x 10 18 cm -3 to 5 x 10 19 cm -3 , and the thickness is 1 μm to 3 μm.

[0035] The active layer 5 is a periodic structure, and the number of periods is 3 to 15. Each period includes an InGaN quantum well layer and a GaN quantum barrier layer stacked in sequence. The thickness of a single InGaN quantum well layer is 2 nm to 5 nm, and the In content is 0.12 to 0.25. The thickness of a single GaN quantum barrier layer is 6 nm to 15 nm.

[0036] The P-type doping element of the first P-GaN layer 7 is Mg or Zn, but not limited to. Preferably, the P-type doping element of the first P-GaN layer 7 is Mg. The P-type doping concentration of the first P-GaN layer 7 is 1 x 10 19 cm -3 to 1 x 10 21 cm -3 . The thickness of the first P-GaN layer 7 is 20 nm to 30 nm.

[0037] The P-type doping element of the second P-GaN layer 9 is Mg or Zn, but not limited to. Preferably, the P-type doping element of the second P-GaN layer 9 is Mg. The P-type doping concentration of the second P-GaN layer 9 is 1 x 10 19 cm -3 to 1 x 10 21 cm -3 . The thickness of the second P-GaN layer 9 is 20 nm to 30 nm.

[0038] Correspondingly, reference is made to Figure 3The application further provides a preparation method of the high-brightness LED epitaxial structure.

[0039] S1: providing a substrate;

[0040] S2: sequentially growing a buffer layer, an undoped GaN layer, an N-GaN layer, an active layer, a barrier layer, a first P-GaN layer, a shunt layer, a second P-GaN layer and a contact layer on the substrate;

[0041] Specifically, step S2 comprises:

[0042] S21: growing the buffer layer on the substrate;

[0043] Specifically, the buffer layer can be grown by a PVD method, an MBE method or an MOCVD method, but is not limited thereto.

[0044] Preferably, in an embodiment of the application, an AlN layer is grown by a PVD method as the buffer layer.

[0045] S22: growing the undoped GaN layer on the buffer layer;

[0046] Specifically, the undoped GaN layer can be grown by an MBE method or an MOCVD method, but is not limited thereto.

[0047] Preferably, in an embodiment of the application, the undoped GaN layer is grown by an MOCVD method, with a growth temperature of 1100-1150°C and a growth pressure of 100-500 torr.

[0048] S23: growing the N-GaN layer on the undoped GaN layer;

[0049] Specifically, the N-GaN layer can be grown by an MBE method or an MOCVD method, but is not limited thereto.

[0050] Preferably, in an embodiment of the application, the N-GaN layer is grown by an MOCVD method, with a growth temperature of 1100-1150°C and a growth pressure of 100-500 torr.

[0051] S24: growing the active layer on the N-GaN layer;

[0052] Specifically, the active layer can be grown by an MBE method or an MOCVD method, but is not limited thereto.

[0053] Preferably, in one embodiment of the present application, the InGaN quantum well layer and the GaN quantum barrier layer are periodically grown by the MOCVD method until the active layer is obtained. The growth temperature of the InGaN quantum well layer is 750-800°C, and the growth pressure is 100-500 torr. The growth temperature of the GaN quantum barrier layer is 850-900°C, and the growth pressure is 100-500 torr.

[0054] S25: growing a superlattice layer on the active layer;

[0055] Specifically, the Mg-doped Al x Ga 1-x N layer can be grown by the MBE method or the MOCVD method as the superlattice layer, but is not limited thereto.

[0056] Preferably, in one embodiment of the present application, the Mg-doped Al x Ga 1-x N layer is grown by the MOCVD method as the superlattice layer, and the growth temperature is 800-850°C, the growth pressure is 150-200 torr, and the growth atmosphere is a mixture of N2 and NH3 with a volume ratio of (1-3):1.

[0057] Specifically, the growth rate of the superlattice layer is controlled to be ≤0.1 μm / h, and N2 is continuously supplied for 10-30 min after the growth is completed to form a plurality of Al quantum dots. Preferably, the growth rate of the superlattice layer is controlled to be 0.05-0.08 μm / h.

[0058] S26: growing a first P-GaN layer on the superlattice layer;

[0059] Specifically, the first P-GaN layer can be grown by the MBE method or the MOCVD method, but is not limited thereto.

[0060] Preferably, in one embodiment of the present application, the first P-GaN layer is grown by the MOCVD method, and the growth temperature is 900-1000°C, and the growth pressure is 100-300 torr.

[0061] S27: growing a shunt layer on the first P-GaN layer;

[0062] Specifically, the AlN layer and the Mg-doped Al y Ga 1-y N layer can be grown by the MBE method or the MOCVD method in sequence as the shunt layer, but is not limited thereto.

[0063] Preferably, in one embodiment of the present application, the AlN layer and the Mg-doped Al y Ga1-y The N layer is grown as a shunt layer. The growth temperature of the two is 890-940℃, the growth pressure is 100-150 torr, and the growth atmosphere is a mixed gas of N2 and NH3, with a volume ratio of (2-6):1.

[0064] Specifically, the growth rate of the Mg-doped Al y Ga 1-y N layer is controlled to be ≤0.1 μm / h, and N2 is continuously introduced after the growth is completed, and stopped for 10-30 min, to form a plurality of Al quantum dots. Preferably, the growth rate of the Mg-doped Al y Ga 1-y N layer is controlled to be 0.03-0.08 μm / h.

[0065] S28: growing a second P-GaN layer on the shunt layer;

[0066] Specifically, the second P-GaN layer can be grown by the MBE method or the MOCVD method, but is not limited thereto.

[0067] Preferably, in one embodiment of the present application, the second P-GaN layer is grown by the MOCVD method, with a growth temperature of 900-1000℃ and a growth pressure of 100-300 torr.

[0068] S29: growing a contact layer on the second P-GaN layer;

[0069] Specifically, the Mg-doped Al z Ga 1-z N layer can be grown by the MBE method or the MOCVD method, but is not limited thereto.

[0070] Preferably, in one embodiment of the present application, the Mg-doped Al z Ga 1-z N layer is grown as a contact layer, with a growth temperature of 980-1030℃, a growth pressure of 200-600 torr, and a growth atmosphere of a mixed gas of N2, H2 and NH3, with a volume ratio of (1-2):(1.5-5):1.

[0071] Specifically, the growth rate of the contact layer is controlled to be ≤0.1 μm / h, and N2 and H2 are continuously introduced after the growth is completed, and stopped for 10-30 min, to form a plurality of Al quantum dots. Preferably, the growth rate of the contact layer is controlled to be 0.05-0.08 μm / h.

[0072] The present application is further described below with specific embodiments:

[0073] Embodiment 1

[0074] Reference Figure 1 and Figure 2 The embodiment provides a high-brightness light-emitting diode epitaxial structure, which comprises a substrate 1, a buffer layer 2, an undoped GaN layer 3, an N-GaN layer 4, an active layer 5, a barrier layer 6, a first P-GaN layer 7, a shunt layer 8, a second P-GaN layer 9 and a contact layer 10 which are sequentially stacked on the substrate 1.

[0075] The substrate 1 is a sapphire substrate, and the buffer layer 2 is an AlN layer with a thickness of 45 nm. The undoped GaN layer has a thickness of 1.5 μm. The N-GaN layer 4 is doped with Si, and the doping concentration is 3×10 19 cm -3 , and the thickness is 2 μm.

[0076] The active layer 5 is a periodic structure, and the period number is 10. Each period comprises an InGaN quantum well layer and a GaN quantum barrier layer which are sequentially stacked. The InGaN quantum well layer has a thickness of 3.2 nm, and the In component ratio is 0.18. The GaN quantum barrier layer has a thickness of 9.5 nm.

[0077] The barrier layer 6 is an Mg-doped Al x Ga 1-x N layer (x=0.18) with a thickness of The Mg doping concentration is 6×10 18 cm -3 . The first P-GaN layer 7 is doped with Mg, and the doping concentration is 3×10 20 cm -3 , and the thickness is 22.8 nm.

[0078] The shunt layer 8 comprises an AlN layer 81 and an Mg-doped Al y Ga 1-y N layer 82 (y=0.18) which are sequentially stacked on the first P-GaN layer 7. The AlN layer 81 has a thickness of The Mg-doped Al y Ga 1-y N layer 82 has a thickness of The Mg doping concentration is 6×10 18 cm -3 . The second P-GaN layer 9 is doped with Mg, and the doping concentration is 3×10 20 cm -3 , and the thickness is 21.9 nm. The contact layer 10 is an Mg-doped Al z Ga 1-z N layer (z=0.18) with a thickness of The Mg doping concentration is 7×10 20 cm-3 .

[0079] Mg-doped Al x Ga 1-x N layer, Mg-doped Al y Ga 1-y N layer, Mg-doped Al z Ga 1-z A plurality of Al quantum dots are formed in the N layer to form a multi-level light taking channel.

[0080] The preparation method of the light emitting diode epitaxial wafer in the embodiment comprises the following steps:

[0081] (1) providing a substrate.

[0082] (2) growing a buffer layer on the substrate;

[0083] The AlN layer is grown on the substrate by the PVD method as the buffer layer.

[0084] (3) growing an undoped GaN layer on the buffer layer;

[0085] The undoped GaN layer is grown by the MOCVD method, and the growth temperature is 1110℃ and the growth pressure is 200 torr.

[0086] (4) growing an N-GaN layer on the undoped GaN layer;

[0087] The N-GaN layer is grown by the MOCVD method, and the growth temperature is 1130℃ and the growth pressure is 300 torr.

[0088] (5) growing an active layer on the N-GaN layer;

[0089] The InGaN quantum well layer and the GaN quantum barrier layer are periodically grown by the MOCVD method until the active layer is obtained. The growth temperature of the InGaN quantum well layer is 760℃ and the growth pressure is 280 torr. The growth temperature of the GaN quantum barrier layer is 880℃ and the growth pressure is 280 torr.

[0090] (6) growing a barrier layer on the active layer;

[0091] The Mg-doped Al x Ga 1-x N layer is grown by the MOCVD method as the barrier layer, and the growth temperature is 820℃, the growth pressure is 180 torr, the growth atmosphere is a mixed gas of N2 and NH3, the volume ratio of the two is 1:1, the growth speed of the barrier layer is 0.07 μm / h, and after the growth is completed, N2 is continuously introduced and stopped for 25 min to form a plurality of Al quantum dots.

[0092] (7) growing a first P-GaN layer on the barrier layer;

[0093] The first P-GaN layer is grown by MOCVD method, the growth temperature is 940°C, and the growth pressure is 200 torr.

[0094] (8) growing a shunt layer on the first P-GaN layer;

[0095] The AlN layer and the Mg-doped Al y Ga 1-y N layer are grown in sequence by MOCVD method as the shunt layer. The growth temperature of the two is 920°C, the growth pressure is 130 torr, the growth atmosphere is a mixed gas of N2 and NH3, and the volume ratio of N2 to NH3 is 5:1. The growth rate of the Mg-doped Al y Ga 1-y N layer is 0.04 μm / h, and after the growth is completed, N2 is continuously introduced for 30 min to form a plurality of Al quantum dots.

[0096] (9) growing a second P-GaN layer on the shunt layer;

[0097] The second P-GaN layer is grown by MOCVD method, the growth temperature is 940°C, and the growth pressure is 200 torr.

[0098] (10) growing a contact layer on the second P-GaN layer;

[0099] The Mg-doped Al z Ga 1-z N layer is grown by MOCVD method as the contact layer, the growth temperature is 1020°C, the growth pressure is 400 torr, the growth atmosphere is a mixed gas of N2, H2 and NH3, and the volume ratio of N2, H2 and NH3 is 1:2:1. The growth rate of the contact layer is 0.07 μm / h, and after the growth is completed, N2 and H2 are continuously introduced for 15 min to form a plurality of Al quantum dots.

[0100] Embodiment 2

[0101] With reference to Embodiments 1 and 2, in this embodiment, x = 0.2, y = 0.3, and z = 0.18. Figure 1 Figure 2 The rest is the same as Embodiment 1.

[0102] Embodiment 3

[0103] With reference to Embodiments 1 to 3, in this embodiment, x = 0.2, y = 0.3, and z = 0.18.

[0104] The rest is the same as Embodiment 1. Figure 1 Figure 2 ​​The embodiment provides a high-brightness light emitting diode epitaxial structure, which is different from the embodiment 2 in that Mg is doped in the Al x Ga 1-x N layer, and the Mg doping concentration in the Mg-doped Al 17 cm -3 .

[0105] The rest are the same as those in the embodiment 2.

[0106] Comparative example 1

[0107] The comparative example provides a light emitting diode epitaxial structure, which is different from the embodiment 1 in that

[0108] Mg is doped in the Al x Ga 1-x N layer, Mg is doped in the Al y Ga 1-y N layer, and Mg is doped in the Al z Ga 1-z N layer.

[0109] The rest are the same as those in the embodiment 1.

[0110] Comparative example 2

[0111] The comparative example provides a light emitting diode epitaxial structure, which is different from the embodiment 1 in that

[0112] Mg is doped in the Al x Ga 1-x N layer, Mg is doped in the Al y Ga 1-y N layer, and Mg is doped in the Al z Ga 1-z N layer.

[0113] The rest are the same as those in the embodiment 1.

[0114] Comparative example 3

[0115] The comparative example provides a light emitting diode epitaxial structure, which is different from the embodiment 1 in that the AlN layer is not included in the shunt layer, and correspondingly, the step of preparing the layer is not included in the preparation method.

[0116] The rest are the same as those in the embodiment 1.

[0117] Comparative example 4

[0118] The comparative example provides a light emitting diode epitaxial structure, which is different from the embodiment 1 in that the barrier layer is not included, and correspondingly, the step of preparing the layer is not included in the preparation method.

[0119] The rest are the same as Example 1.

[0120] Comparative Example 5

[0121] This comparative example provides a light emitting diode epitaxial structure, which is different from Example 1 in that it does not include a shunt layer, and correspondingly, the preparation method does not include the step of preparing the layer.

[0122] The rest are the same as Example 1.

[0123] Comparative Example 6

[0124] This comparative example provides a light emitting diode epitaxial structure, which is different from Example 1 in that it does not include a contact layer, and correspondingly, the preparation method does not include the step of preparing the layer.

[0125] The rest are the same as Example 1.

[0126] The epitaxial structures obtained in Examples 1-3 and Comparative Examples 1-6 are made into 5 mil x 7 mil horizontal structure chips, and their luminous brightness and operating voltage at 20 mA are tested;

[0127] The specific test results are shown in the following table:

[0128] Luminous brightness / mW Operating voltage (V) Example 1 17.3 2.95 Example 2 18.5 2.93 Example 3 19.6 2.82 Comparative Example 1 8.1 3.12 Comparative Example 2 8.5 3.33 Comparative Example 3 10.5 2.99 Comparative Example 4 10.8 2.83 Comparative Example 5 6.4 2.76 Comparative Example 6 9.7 2.95

[0129] The above is the preferred embodiment of the application. It should be noted that for those skilled in the art, without departing from the principles of the application, a number of improvements and refinements can be made, which are also considered within the scope of protection of the application.

Claims

1. A high-brightness light-emitting diode epitaxial structure, characterized in that, It includes a substrate, and a buffer layer, an undoped GaN layer, an N-GaN layer, an active layer, a barrier layer, a first P-GaN layer, a shunt layer, a second P-GaN layer, and a contact layer, which are sequentially stacked on the substrate. The barrier layer is Mg-doped Al. x Ga 1-x The N-layer has a x value of 0.1 to 0.3; the shunt layer comprises an AlN layer and a Mg-doped Al layer sequentially stacked on the first P-GaN layer. y Ga 1-y N layer, y is 0.15–0.35; the contact layer is Mg-doped Al. z Ga 1-z For layer N, z is 0.1 to 0.2; The Mg-doped Al x Ga 1-x N-layer, Mg-doped Al y Ga 1-y N-layer, Mg-doped Al z Ga 1-z Multiple Al quantum dots are formed in each of the N layers to create multi-layered light-harvesting channels.

2. The high-brightness light-emitting diode epitaxial structure as described in claim 1, characterized in that, The Mg-doped Al x Ga 1-x The Mg doping concentration in the N layer is 5 × 10⁻⁶. 17 cm -3 ~8×10 18 cm -3 Thickness is 3. The high-brightness light-emitting diode epitaxial structure as described in claim 1, characterized in that, The Mg-doped Al y Ga 1-y The Mg doping concentration in the N-layer is 1×10⁻⁶. 18 cm -3 ~9×10 18 cm -3 Thickness is The thickness of the AlN layer is 4. The high-brightness light-emitting diode epitaxial structure as described in claim 1, characterized in that, The Mg-doped Al z Ga 1-z The Mg doping concentration in the N layer is 5 × 10⁻⁶. 19 cm -3 ~2×10 20 cm -3 Thickness is 5. A method for fabricating a high-brightness light-emitting diode epitaxial structure, used to fabricate the high-brightness light-emitting diode epitaxial structure as described in any one of claims 1 to 4, characterized in that, include: A substrate is provided on which a buffer layer, an undoped GaN layer, an N-GaN layer, an active layer, a barrier layer, a first P-GaN layer, a shunt layer, a second P-GaN layer, and a contact layer are sequentially grown. The barrier layer is Mg-doped Al. x Ga 1-x The N-layer has a x value of 0.1 to 0.3; the shunt layer comprises an AlN layer and a Mg-doped Al layer sequentially stacked on the first P-GaN layer. y Ga 1-y N layer, y is 0.15–0.35; the contact layer is Mg-doped Al. z Ga 1-z For layer N, z is 0.1 to 0.2; Wherein, the Mg doped with Al x Ga 1-x N-layer, Mg-doped Al y Ga 1-y N-layer, Mg-doped Al z Ga 1-z The growth rate of the N layer is ≤0.1 μm / h, and the growth is stopped for 10 min to 30 min after completion, so that the Mg-doped Al layer can be further processed. x Ga 1-x N-layer, Mg-doped Al y Ga 1-y N-layer, Mg-doped Al z Ga 1- z Multiple Al quantum dots are formed in the N layer.

6. The method for fabricating a high-brightness light-emitting diode epitaxial structure as described in claim 5, characterized in that, The growth temperature of the barrier layer is 800℃~850℃, the growth pressure is 150torr~200torr, and the growth atmosphere is a mixture of N2 and NH3 in a volume ratio of (1~3):

1.

7. The method for fabricating a high-brightness light-emitting diode epitaxial structure as described in claim 5, characterized in that, The growth temperature of the shunt layer is 890℃~940℃, the growth pressure is 100torr~150torr, and the growth atmosphere is a mixture of N2 and NH3 in a volume ratio of (2~6):

1.

8. The method for fabricating a high-brightness light-emitting diode epitaxial structure as described in claim 5, characterized in that, The growth temperature of the contact layer is 980℃~1030℃, the growth pressure is 200torr~600torr, and the growth atmosphere is a mixture of N2, H2 and NH3, with a volume ratio of N2, H2 and NH3 of (1~2):(1.5~5):

1.

9. A high-brightness LED, characterized in that, Includes the high-brightness light-emitting diode epitaxial structure as described in any one of claims 1 to 4.

Images