Light-emitting diode epitaxial wafer, its preparation method, 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 light-emitting diode epitaxial wafer includes a substrate, and a nucleation layer, an intrinsic GaN layer, an N-type semiconductor layer, a multi-quantum well layer, an electron blocking layer, and a P-type semiconductor layer which are sequentially disposed on the substrate; the electron blocking layer includes a first sub-layer and a second sub-layer which are sequentially stacked; wherein, the first sub-layer is a MgInGaN layer; the second sub-layer includes a Ga<subgt;2< / subgt>O<subgt;3< / subgt> layer and a MgGaN layer which are sequentially stacked. Implementing the present invention can improve the light-emitting efficiency of the light-emitting diode and reduce the working voltage.

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] At present, GaN-based light-emitting diodes have been widely used in the fields of solid-state lighting and display, attracting more and more attention. The epitaxial structure has a great influence on the optoelectronic properties of the light-emitting diode. Traditional light-emitting diode epitaxial wafers include: a substrate, and a nucleation layer, an intrinsic GaN layer, an N-type semiconductor layer, a multi-quantum well layer, an electron blocking layer, and a P-type semiconductor layer sequentially grown on the substrate. Due to the high electron mobility, at present, high-Al-doped AlGaN materials or AlGaN / InGaN superlattice materials are used as the electron blocking layer. However, a high Al component will bring a high operating voltage and have a certain blocking effect on holes. Moreover, due to the low mobility of Al atoms and high viscosity effect, the distribution of Al atoms is uneven, affecting electron blocking and causing electron overflow, resulting in a reduction in light-emitting efficiency. Summary of the Invention

[0003] 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 reduce the operating voltage of the light-emitting diode and improve the light-emitting efficiency.

[0004] Another technical problem to be solved by the present invention is to provide a light-emitting diode with high light-emitting efficiency and low operating voltage.

[0005] To solve the above problems, the present invention discloses a light-emitting diode epitaxial wafer, which includes a substrate and a nucleation layer, an intrinsic GaN layer, an N-type semiconductor layer, a multi-quantum well layer, an electron blocking layer, and a P-type semiconductor layer sequentially provided on the substrate; the electron blocking layer includes a first sub-layer and a second sub-layer stacked in sequence;

[0006] Wherein, the first sub-layer is a MgInGaN layer;

[0007] The second sub-layer includes a Ga2O3 layer and a MgGaN layer stacked in sequence.

[0008] As an improvement of the above technical solution, the proportion of In component in the MgInGaN layer gradually decreases from 0.2 - 0.4 to 0 along the epitaxial direction.

[0009] As an improvement of the above technical solution, the doping concentration of Mg in the MgInGaN layer is 1×10 15 cm -3 -1×10 16 cm -3, the thickness of the MgInGaN layer is 5 nm - 50 nm.

[0010] As an improvement of the above technical solution, the In source in the MgInGaN layer is intermittently introduced, where the interruption time is 1 s - 5 s and the introduction time is 5 s - 10 s;

[0011] The Ga source in the MgInGaN layer is intermittently introduced. When the In source is interrupted, the Ga source is introduced, and the introduction time of the Ga source is the same as the interruption time of the In source; when the In source is introduced, the Ga source is interrupted, and the interruption time of the Ga source is the same as the introduction time of the In source.

[0012] As an improvement of the above technical solution, the thickness of the Ga2O3 layer is 15 nm - 200 nm;

[0013] The thickness of the MgGaN layer is 3 nm - 50 nm, and the doping concentration of Mg is 1×10 17 cm -3 -1×10 18 cm -3 .

[0014] As an improvement of the above technical solution, the second sub-layer is a periodic structure with the number of periods being 3 - 10;

[0015] Among them, the thickness of a single Ga2O3 layer is 5 nm - 20 nm;

[0016] The thickness of a single MgGaN layer is 1 nm - 5 nm.

[0017] 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:

[0018] Providing a substrate, and sequentially growing a nucleation layer, an intrinsic GaN layer, an N-type semiconductor layer, a multi-quantum well layer, an electron blocking layer, and a P-type semiconductor layer on the substrate; the electron blocking layer includes a first sub-layer and a second sub-layer stacked in sequence;

[0019] Among them, the first sub-layer is a MgInGaN layer;

[0020] The second sub-layer includes a Ga2O3 layer and a MgGaN layer stacked in sequence.

[0021] As an improvement of the above technical solution, the growth temperature of the first sub-layer gradually increases from 750 °C - 800 °C to 850 °C - 900 °C, and the growth pressure is 100 torr - 300 torr;

[0022] The growth temperature of the second sub-layer is 950 °C - 1000 °C, and the growth pressure is 100 torr - 300 torr.

[0023] As an improvement of the above technical solution, the carrier gas used when the first sub-layer and the second sub-layer are grown is N2.

[0024] Correspondingly, the present invention also discloses a light-emitting diode, which includes the above-mentioned light-emitting diode epitaxial wafer.

[0025] Implementing the present invention has the following beneficial effects:

[0026] 1. In the light-emitting diode epitaxial wafer of the present invention, the electron blocking layer includes a first sub-layer and a second sub-layer stacked in sequence. Among them, the first sub-layer is a MgInGaN layer. First, Mg doping in the MgInGaN layer can generate some holes, consume some electrons, reduce electron overflow, increase electron-hole pairs, and improve the light-emitting efficiency; second, the first sub-layer is connected to the multi-quantum well layer and uses a material similar to the multi-quantum well layer, which can reduce the lattice mismatch with the multi-quantum well layer, improve the lattice quality, and reduce the energy band spike caused by the excessive change of the energy band between the traditional electron blocking layer and the multi-quantum well layer, avoiding affecting hole injection and improving the light-emitting efficiency.

[0027] Among them, the second sub-layer includes a Ga2O3 layer and a MgGaN layer stacked in sequence. First, the Ga2O3 material has a large band gap and has a good electron blocking effect, and it has a low on-resistance. Therefore, compared with the traditional use of high-Al-doped AlGaN material or AlGaN / InGaN material as the electron blocking layer, Ga2O3 can not only block electrons from passing through, but also will not cause the working voltage to increase; second, the MgGaN layer can increase the hole concentration, and then increase the hole concentration entering the multi-quantum well layer, improving the light-emitting efficiency; finally, the carrier mobility in the Ga2O3 material is relatively high, and the holes generated by the MgGaN layer enter the multi-quantum well layer through the Ga2O3 layer, further increasing the hole injection in the multi-quantum well layer and improving the light-emitting efficiency.

[0028] 2. In the light-emitting diode epitaxial wafer of the present invention, the proportion of In component in the MgInGaN layer gradually decreases from 0.2 - 0.4 to 0 along the epitaxial growth direction, making the energy levels between the electron blocking layer, the multi-quantum well layer and the P-type semiconductor layer transition smoothly, increasing the hole injection in the multi-quantum well layer, and improving the light-emitting efficiency.

[0029] 3. In the light-emitting diode epitaxial wafer of the present invention, the In source and the Ga source are intermittently introduced. When the In source is interrupted, the Ga source is introduced; when the In source is introduced, the Ga source is interrupted. The growth method of intermittently introducing the In source and the Ga source and continuously supplying the N source without interruption helps to eliminate defects such as In clusters and In droplets formed on the material surface, improve the lattice quality, avoid defects from becoming non-radiative recombination centers, and improve the light-emitting efficiency.

[0030] 4. In the light-emitting diode epitaxial wafer of the present invention, the second sub-layer is a periodic structure. Periodic stacking generates a strong built-in electric field, which can reduce the acceptor energy level, generate a two-dimensional hole gas, increase the hole mobility, thereby increasing the hole concentration entering the multi-quantum well layer, and improving the light-emitting efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic structural diagram of a light-emitting diode epitaxial wafer in an embodiment of the present invention;

[0032] Figure 2 is a schematic structural diagram of an electron blocking layer in an embodiment of the present invention;

[0033] Figure 3 is a schematic structural diagram of a first sub-layer in an embodiment of the present invention;

[0034] Figure 4 is a schematic structural diagram of a second sub-layer in an embodiment of the present invention;

[0035] Figure 5 is a schematic structural diagram of a second sub-layer in another embodiment of the present invention;

[0036] Figure 6 is a flowchart of a method for preparing a light-emitting diode epitaxial wafer in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below.

[0038] Reference Figures 1 - 4 , the present invention discloses a light-emitting diode epitaxial wafer, including a substrate 1 and a nucleation layer 2, an intrinsic GaN layer 3, an N-type semiconductor layer 4, a multi-quantum well layer 5, an electron blocking layer 6, and a P-type semiconductor layer 7 sequentially disposed on the substrate 1; wherein, the electron blocking layer 6 includes a first sub-layer 61 and a second sub-layer 62 stacked in sequence. Among them, the first sub-layer 61 is a MgInGaN layer 611. First, Mg doping in the MgInGaN layer 611 can generate some holes, consume some electrons, reduce electron overflow, increase electron-hole pairs, and improve the light-emitting efficiency; second, the first sub-layer 61 is connected to the multi-quantum well layer 5, and using a material similar to the multi-quantum well layer 5 can reduce the lattice mismatch with the multi-quantum well layer 5, improve the lattice quality, and reduce the energy band spike caused by the too large energy band change between the traditional electron blocking layer and the multi-quantum well layer, avoiding affecting hole injection and improving the light-emitting efficiency.

[0039] Preferably, in an embodiment of the present invention, the proportion of In component in the MgInGaN layer 611 gradually decreases from 0.2 - 0.4 to 0 along the epitaxial growth direction, enabling a smooth transition of the energy levels between the electron blocking layer 6, the multi - quantum well layer 5, and the P - type semiconductor layer 7, increasing the injection of holes in the multi - quantum well layer 5, and improving the light - emitting efficiency.

[0040] Among them, the doping concentration of Mg in the MgInGaN layer 611 is 5×10 14 cm -3 -5×10 16 cm -3 , when the doping concentration < 5×10 14 cm -3 , it is difficult to provide sufficient holes; when the doping concentration > 5×10 16 cm -3 , it will bring too many defects. Preferably, the doping concentration of Mg in the MgInGaN layer 611 is 1×10 15 cm -3 -1×10 16 cm -3 , exemplary ones are 2×10 15 cm -3 , 3×10 15 cm -3 , 4×10 15 cm -3 , 5×10 15 cm -3 , 6×10 15 cm -3 , 7×10 15 cm -3 , 8×10 15 cm -3 or 9×10 15 cm -3 , but not limited thereto.

[0041] The thickness of the MgInGaN layer 611 is 3 nm - 60 nm. When its thickness < 3 nm, it is difficult to provide sufficient holes; when its thickness > 60 nm, it will bring too many defects. Preferably, the thickness of the MgInGaN layer 611 is 5 nm - 50 nm, exemplary ones are 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm or 45 nm, but not limited thereto.

[0042] Preferably, in another embodiment of the present invention, the In source in the MgInGaN layer 611 is intermittently introduced, where the interruption time is 1 s - 5 s and the introduction time is 5 s - 10 s; the Ga source in the MgInGaN layer is intermittently introduced. When the In source is interrupted, the Ga source is introduced, and the introduction time of the Ga source is the same as the interruption time of the In source; when the In source is introduced, the Ga source is interrupted, and the interruption time of the Ga source is the same as the introduction time of the In source. The growth method of intermittently introducing the In source and the Ga source and continuously supplying the N source without interruption helps to eliminate defects such as In clusters and In droplets formed on the material surface, improve the lattice quality, avoid defects from becoming non-radiative recombination centers, and improve the light emission efficiency.

[0043] Among them, the second sub-layer 62 includes a Ga2O3 layer 621 and a MgGaN layer 622 stacked in sequence. First, the Ga2O3 material has a large bandgap and has a good electron blocking effect, and it has a low on-resistance. Therefore, compared with the traditional use of highly Al-doped AlGaN materials or AlGaN / InGaN materials as the electron blocking layer, Ga2O3 can not only block the access of electrons but also will not cause an increase in the operating voltage; secondly, the MgGaN layer 622 can increase the hole concentration, thereby increasing the hole concentration entering the multi-quantum well layer 5 and improving the light emission efficiency; finally, the carrier mobility in the Ga2O3 material is relatively high, and the holes generated by the MgGaN layer 622 enter the multi-quantum well layer 5 through the Ga2O3 layer 621, further increasing the injection of holes in the multi-quantum well layer 5 and improving the light emission efficiency.

[0044] Specifically, the thickness of the Ga2O3 layer 621 is 10 nm - 220 nm. When its thickness < 10 nm, it is difficult to effectively play the role of electron blocking; when its thickness > 220 nm, the preparation efficiency is too low. Preferably, the thickness of the Ga2O3 layer 621 is 15 nm - 200 nm, and examples are 20 nm, 30 nm, 50 nm, 80 nm, 100 nm, 120 nm, 150 nm, 170 nm or 180 nm, but not limited thereto.

[0045] The thickness of the MgGaN layer 622 is 2 nm - 60 nm. When its thickness < 2 nm, it is difficult to effectively increase the hole concentration; when its thickness > 60 nm, it will bring too many defects. Preferably, the thickness of the MgGaN layer 622 is 3 nm - 50 nm, and examples are 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm or 45 nm, but not limited thereto.

[0046] The doping concentration of Mg in the MgGaN layer 622 is 5×10 16 cm -3 -5×10 18 cm -3. When the doping concentration of Mg < 5×10 16 cm -3 , it is difficult to effectively increase the hole concentration; when the doping concentration of Mg > 5×10 18 cm -3 , it will bring too many defects. Preferably, the doping concentration of Mg is 1×10 17 cm -3 -1×10 18 cm -3 , and exemplary ones are 2×10 17 cm -3 , 3×10 17 cm -3 , 4×10 17 cm -3 , 5×10 17 cm -3 , 6×10 17 cm -3 , 7×10 17 cm -3 , 8×10 17 cm -3 or 9×10 17 cm -3 , but not limited thereto.

[0047] Preferably, in another embodiment of the present invention, referring to Figure 5 , the second sub-layer 62 is a periodic structure, and the number of periods is 3 - 10, and exemplary ones are 4, 5, 6, 7, 8 or 9, but not limited thereto. The periodic stacking will generate a strong built-in electric field, which can reduce the acceptor energy level and generate a two-dimensional hole gas, increasing the hole mobility, thereby increasing the hole concentration entering the multi-quantum well layer 5 and improving the light-emitting efficiency.

[0048] Specifically, the thickness of a single Ga2O3 layer 621 is 5 nm - 20 nm, and exemplary ones are 8 nm, 10 nm, 12 nm, 14 nm, 16 nm or 18 nm, but not limited thereto.

[0049] The thickness of a single MgGaN layer 622 is 1 nm - 5 nm, and exemplary ones are 2 nm, 2.5 nm, 3 nm, 3.5 nm, 4 nm or 4.5 nm, but not limited thereto.

[0050] Among them, the substrate 1 can be a sapphire substrate, a silicon substrate, a silicon carbide substrate, but not limited thereto.

[0051] Among them, the nucleation layer 2 can be an AlN layer and / or an AlGaN layer, but not limited thereto. The thickness of the nucleation layer 2 is 20 nm - 100 nm, and exemplary ones are 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm or 90 nm, but not limited thereto.

[0052] Among them, the thickness of the intrinsic GaN layer 3 is 300 nm - 800 nm, and exemplary values are 350 nm, 400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm or 750 nm, but not limited thereto.

[0053] Among them, the doping element of the N-type semiconductor layer 4 is Si, but not limited thereto. The doping concentration of the N-type semiconductor layer 4 is 5×10 18 cm -3 -1×10 19 cm -3 , and the thickness is 1 μm - 3 μm.

[0054] Among them, the multi-quantum well layer 5 is an alternately stacked InGaN quantum well layer and GaN quantum barrier layer, and the number of stacking periods is 3 - 15. The thickness of a single InGaN quantum well layer is 2 nm - 5 nm, and the thickness of a single GaN quantum barrier layer is 6 nm - 15 nm.

[0055] Among them, the doping element in the P-type semiconductor layer 7 is Mg, but not limited thereto. The doping concentration of Mg in the P-type semiconductor layer 7 is 5×10 17 cm -3 -1×10 20 cm -3 . The thickness of the P-type semiconductor layer 7 is 6 nm - 60 nm.

[0056] Correspondingly, referring to Figure 6 , the present invention also discloses a method for preparing a light-emitting diode epitaxial wafer, which is used to prepare the above-mentioned light-emitting diode epitaxial wafer, and includes the following steps:

[0057] S100: Provide a substrate;

[0058] Specifically, the substrate is a sapphire substrate, a silicon substrate, a silicon carbide substrate, but not limited thereto. Preferably, it is a sapphire substrate.

[0059] Preferably, in an embodiment of the present invention, the substrate is loaded into MOCVD and annealed for 5 min - 8 min at 1000 °C - 1200 °C, 200 torr - 600 torr, and in a hydrogen atmosphere to remove impurities such as particles and oxides on the surface of the substrate.

[0060] S200: Grow a nucleation layer on the substrate;

[0061] Specifically, an AlGaN layer can be grown by MOCVD as the nucleation layer, or an AlN layer can be grown by PVD as the nucleation layer, but it is not limited thereto. Preferably, an AlGaN layer is grown by MOCVD, with a growth temperature of 500°C - 700°C and a growth pressure of 200 torr - 400 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source; H2 and N2 are used as carrier gases, TMAl is introduced as the Al source, and TMGa is introduced as the Ga source.

[0062] S300: Grow an intrinsic GaN layer on the nucleation layer;

[0063] Specifically, an intrinsic GaN layer is grown in MOCVD, with a growth temperature of 1100°C - 1150°C and a growth pressure of 100 torr - 500 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source; H2 and N2 are used as carrier gases, and TMGa is introduced as the Ga source.

[0064] S400: Grow an N-type semiconductor layer on the intrinsic GaN layer;

[0065] Specifically, an N-type semiconductor layer is grown in MOCVD, with a growth temperature of 1100°C - 1150°C and a growth pressure of 100 torr - 500 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source, SiH4 is introduced as the N-type doping source; H2 and N2 are used as carrier gases, and TMGa is introduced as the Ga source.

[0066] S500: Grow a multi-quantum well layer on the N-type semiconductor layer;

[0067] Specifically, the quantum well layer and the quantum barrier layer are grown periodically in MOCVD to form a multi-quantum well layer. Among them, the growth temperature of the quantum well layer is 700°C - 800°C, the growth pressure is 100 torr - 500 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source, N2 is used as the carrier gas, TEGa is introduced as the Ga source, and TMIn is introduced as the In source. Among them, the growth temperature of the quantum barrier layer is 800°C - 900°C, the growth pressure is 100 torr - 500 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source, H2 and N2 are used as carrier gases, and TEGa is introduced as the Ga source.

[0068] S600: Grow an electron blocking layer on the multi-quantum well layer;

[0069] Specifically, in one embodiment of the present invention, S600 includes:

[0070] S610: Grow a first sub-layer on the multi-quantum well layer;

[0071] Specifically, in MOCVD, the MgInGaN layer is grown as the first sub-layer, and the growth conditions of the first sub-layer are the same as those of the MgInGaN layer commonly used in the art. Preferably, in an embodiment of the present invention, the growth temperature of the first sub-layer gradually increases from 750°C - 800°C to 850°C - 900°C, the growth pressure is 100 torr - 300 torr, NH3 is introduced as the N source, CP2Mg is introduced as the Mg source, TMIn is introduced as the In source, TEGa is introduced as the Ga source, and the carrier gas used during growth is N2. Using N2 as the carrier gas is beneficial for the incorporation of the In component. First, a lower growth temperature is adopted. A low temperature is beneficial for the incorporation of the In component. Along the epitaxial direction, the In component gradually decreases. Therefore, gradually increasing the growth temperature is beneficial for improving the lattice quality.

[0072] Preferably, in another embodiment of the present invention, the In source and the Ga source are introduced intermittently. When the In source is interrupted, the Ga source is introduced, and the introduction time of the Ga source is the same as the interruption time of the In source; when the In source is introduced, the Ga source is interrupted, and the interruption time of the Ga source is the same as the introduction time of the In source. The growth method of intermittently introducing the In source and the Ga source while continuously supplying the N source without interruption helps to eliminate defects such as In clusters and In droplets formed on the material surface, improve the lattice quality, prevent the defects from becoming non-radiative recombination centers, and improve the luminescence efficiency.

[0073] S620: Grow the second sub-layer on the first sub-layer;

[0074] Specifically, in MOCVD, the Ga2O3 layer and the MgGaN layer are sequentially stacked and grown as the second sub-layer. Preferably, in an embodiment of the present invention, the Ga2O3 layer and the MgGaN layer are periodically stacked and grown in MOCVD as the second sub-layer. The growth temperature of the second sub-layer is 950°C - 1000°C, and the growth pressure is 100 torr - 300 torr. Specifically, when growing the Ga2O3 layer, O2 is introduced as the O source, and TEGa is introduced as the Ga source, and the carrier gas used during growth is N2. When growing the MgGaN layer, NH3 is introduced as the N source, CP2Mg is introduced as the Mg source, and TEGa is introduced as the Ga source, and the carrier gas used during growth is N2.

[0075] Using N2 as the carrier gas when growing the Ga2O3 layer avoids the formation of excessive H2O when H2 is used as the carrier gas, which affects the formation of Ga2O3. Using N2 as the carrier gas when growing the MgGaN layer prevents the formation of Mg-H complexes, which affects the activation of Mg.

[0076] S700: Grow the P-type semiconductor layer on the electron blocking layer;

[0077] Specifically, when growing the P-type semiconductor layer by MOCVD, the growth temperature is 800°C - 1000°C, and the growth pressure is 100 torr - 300 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source, and Cp2Mg is introduced as the P-type doping source; H2 and N2 are used as carrier gases, and TMGa is introduced as the Ga source.

[0078] The following further illustrates the present invention with specific embodiments:

[0079] Embodiment 1

[0080] This embodiment provides a light-emitting diode epitaxial wafer, referring to Figures 1 - 4 , which includes a substrate 1 and a nucleation layer 2, an intrinsic GaN layer 3, an N-type semiconductor layer 4, a multi-quantum well layer 5, an electron blocking layer 6, and a P-type semiconductor layer 7 sequentially provided on the substrate 1.

[0081] Among them, the substrate 1 is a sapphire substrate; the nucleation layer 2 is an AlGaN layer with a thickness of 30 nm; the thickness of the intrinsic GaN layer 3 is 400 nm; the doping concentration of Si in the N-type semiconductor layer 4 is 7×10 18 cm -3 , and its thickness is 2 μm. The multi-quantum well layer 5 is an alternately stacked InGaN quantum well layer and GaN quantum barrier layer, with a stacking period number of 10. The thickness of a single InGaN quantum well layer is 3 nm, and the thickness of a single GaN quantum barrier layer is 10 nm.

[0082] Among them, the electron blocking layer 6 includes a first sub-layer 61 and a second sub-layer 62 stacked in sequence. Among them, the first sub-layer 61 is a MgInGaN layer 611. The proportion of In component in the MgInGaN layer 611 is 0.3, and the doping concentration of Mg is 5×10 15 cm -3 , and its thickness is 15 nm.

[0083] Among them, the second sub-layer 62 includes a Ga2O3 layer 621 and a MgGaN layer 622 stacked in sequence. Among them, the thickness of the Ga2O3 layer 621 is 50 nm. The doping concentration of Mg in the MgGaN layer 622 is 5×10 17 cm -3 , and its thickness is 20 nm.

[0084] The doping element of the P-type semiconductor layer 7 is Mg, and the doping concentration is 3.5×10 19 cm -3 , and the thickness is 10 nm.

[0085] The preparation method of the light-emitting diode epitaxial wafer in this embodiment includes the following steps:

[0086] (1) Provide a substrate; load the substrate into MOCVD and anneal it for 6 min at 1120 °C, 400 torr under a hydrogen atmosphere.

[0087] (2) Grow a nucleation layer on the substrate;

[0088] Specifically, grow an AlGaN layer by MOCVD, with a growth temperature of 620 °C and a growth pressure of 250 torr. During growth, introduce NH3 as the N source into the MOCVD reaction chamber; use H2 and N2 as carrier gases, introduce TMAl as the Al source, and introduce TMGa as the Ga source.

[0089] (3) Grow an intrinsic GaN layer on the nucleation layer;

[0090] Specifically, grow an intrinsic GaN layer by MOCVD, with a growth temperature of 1100 °C and a growth pressure of 250 torr. During growth, introduce NH3 as the N source into the MOCVD reaction chamber; use H2 and N2 as carrier gases, and introduce TMGa as the Ga source.

[0091] (4) Grow an N-type semiconductor layer on the intrinsic GaN layer;

[0092] Specifically, grow an N-type semiconductor layer by MOCVD, with a growth temperature of 1120 °C and a growth pressure of 150 torr; during growth, introduce NH3 as the N source into the MOCVD reaction chamber, introduce SiH4 as the N-type doping source; use H2 and N2 as carrier gases, and introduce TMGa as the Ga source.

[0093] (5) Grow a multi-quantum well layer on the N-type semiconductor layer;

[0094] Specifically, grow quantum well layers and quantum barrier layers periodically in MOCVD to obtain a multi-quantum well layer;

[0095] Among them, the growth temperature of the quantum well layer is 750 °C, the growth pressure is 300 torr. During growth, introduce NH3 as the N source into the MOCVD reaction chamber, use N2 as the carrier gas, introduce TEGa as the Ga source, and introduce TMIn as the In source; among them, the growth temperature of the quantum barrier layer is 820 °C, the growth pressure is 300 torr. During growth, introduce NH3 as the N source into the MOCVD reaction chamber, use H2 and N2 as carrier gases, and introduce TEGa as the Ga source.

[0096] (6) Grow an electron blocking layer on the multi-quantum well layer;

[0097] Specifically, the preparation method of each electron blocking layer includes:

[0098] (Ⅰ) Grow a first sub-layer on the multi-quantum well layer;

[0099] Specifically, a MgInGaN layer is grown in MOCVD as the first sublayer. The growth temperature of the first sublayer is 780 °C, the growth pressure is 200 torr, NH3 is introduced as the N source, CP2Mg is introduced as the Mg source, TMIn is introduced as the In source, TEGa is introduced as the Ga source, and the carrier gas used during growth is N2.

[0100] (II) A second sublayer is grown on the first sublayer;

[0101] Specifically, a Ga2O3 layer and a MgGaN layer are sequentially stacked and grown in MOCVD as the second sublayer. The growth temperature of the second sublayer is 980 °C, and the growth pressure is 200 torr. Specifically, when growing the Ga2O3 layer, O2 is introduced as the O source, TEGa is introduced as the Ga source, and the carrier gas used during growth is N2. When growing the MgGaN layer, NH3 is introduced as the N source, CP2Mg is introduced as the Mg source, TEGa is introduced as the Ga source, and the carrier gas used during growth is N2.

[0102] (7) A P-type semiconductor layer is grown on the electron blocking layer;

[0103] Specifically, a P-type semiconductor layer is grown in MOCVD. The growth temperature is 900 °C, and the growth pressure is 200 torr. During growth, NH3 is introduced as the N source and Cp2Mg is introduced as the P-type doping source into the MOCVD reaction chamber; H2 and N2 are used as carrier gases, and TMGa is introduced as the Ga source.

[0104] Example 2

[0105] This example provides a light-emitting diode epitaxial wafer, referring to Figures 1 - 4 , which includes a substrate 1, and a nucleation layer 2, an intrinsic GaN layer 3, an N-type semiconductor layer 4, a multi-quantum well layer 5, an electron blocking layer 6, and a P-type semiconductor layer 7 sequentially provided on the substrate 1.

[0106] Among them, the substrate 1 is a sapphire substrate; the nucleation layer 2 is an AlGaN layer with a thickness of 30 nm; the thickness of the intrinsic GaN layer 3 is 400 nm; the doping concentration of Si in the N-type semiconductor layer 4 is 7×10 18 cm -3 , and its thickness is 2 μm. The multi-quantum well layer 5 is an alternately stacked InGaN quantum well layer and GaN quantum barrier layer, the number of stacking periods is 10, the thickness of a single InGaN quantum well layer is 3 nm, and the thickness of a single GaN quantum barrier layer is 10 nm.

[0107] Among them, the electron blocking layer 6 includes a first sub-layer 61 and a second sub-layer 62 stacked in sequence. Among them, the first sub-layer 61 is a MgInGaN layer 611. In the MgInGaN layer 611, the proportion of In component gradually decreases from 0.3 to 0 along the epitaxial growth direction, and the doping concentration of Mg is 5×10 15 cm -3 , and its thickness is 15 nm.

[0108] Among them, the second sub-layer 62 includes a Ga2O3 layer 621 and a MgGaN layer 622 stacked in sequence. Among them, the thickness of the Ga2O3 layer 621 is 50 nm. The doping concentration of Mg in the MgGaN layer 622 is 5×10 17 cm -3 , and its thickness is 20 nm.

[0109] The doping element of the P-type semiconductor layer 7 is Mg, and the doping concentration is 3.5×10 19 cm -3 , and the thickness is 10 nm.

[0110] The preparation method of the light-emitting diode epitaxial wafer in this embodiment includes the following steps:

[0111] (1) Provide a substrate; load the substrate into the MOCVD and anneal it for 6 minutes at 1120°C, 400 torr, and in a hydrogen atmosphere.

[0112] (2) Grow a nucleation layer on the substrate;

[0113] Specifically, grow an AlGaN layer by MOCVD, with a growth temperature of 620°C and a growth pressure of 250 torr. During growth, introduce NH3 as the N source into the MOCVD reaction chamber; use H2 and N2 as carrier gases, introduce TMAl as the Al source, and introduce TMGa as the Ga source.

[0114] (3) Grow an intrinsic GaN layer on the nucleation layer;

[0115] Specifically, grow an intrinsic GaN layer by MOCVD, with a growth temperature of 1100°C and a growth pressure of 250 torr. During growth, introduce NH3 as the N source into the MOCVD reaction chamber; use H2 and N2 as carrier gases, and introduce TMGa as the Ga source.

[0116] (4) Grow an N-type semiconductor layer on the intrinsic GaN layer;

[0117] Specifically, grow an N-type semiconductor layer by MOCVD, with a growth temperature of 1120°C and a growth pressure of 150 torr; during growth, introduce NH3 as the N source into the MOCVD reaction chamber, introduce SiH4 as the N-type doping source; use H2 and N2 as carrier gases, and introduce TMGa as the Ga source.

[0118] (5) Grow a multi-quantum well layer on the N-type semiconductor layer;

[0119] Specifically, grow quantum well layers and quantum barrier layers periodically in MOCVD to obtain a multi-quantum well layer;

[0120] Among them, the growth temperature of the quantum well layer is 750 °C, the growth pressure is 300 torr. When growing, NH3 is introduced into the MOCVD reaction chamber as the N source, N2 is used as the carrier gas, TEGa is introduced as the Ga source, and TMIn is introduced as the In source; among them, the growth temperature of the quantum barrier layer is 820 °C, the growth pressure is 300 torr. When growing, NH3 is introduced into the MOCVD reaction chamber as the N source, H2 and N2 are used as the carrier gases, and TEGa is introduced as the Ga source.

[0121] (6) Grow an electron blocking layer on the multi-quantum well layer;

[0122] Specifically, the preparation method of each electron blocking layer includes:

[0123] (Ⅰ) Grow a first sub-layer on the multi-quantum well layer;

[0124] Specifically, grow a MgInGaN layer in MOCVD as the first sub-layer. The growth temperature of the first sub-layer gradually increases from 780 °C to 880 °C, the growth pressure is 200 torr, NH3 is introduced as the N source, CP2Mg is introduced as the Mg source, TMIn is introduced as the In source, and TEGa is introduced as the Ga source. The carrier gas used during growth is N2.

[0125] (Ⅱ) Grow a second sub-layer on the first sub-layer;

[0126] Specifically, grow a Ga2O3 layer and a MgGaN layer successively in MOCVD as the second sub-layer. The growth temperature of the second sub-layer is 980 °C, and the growth pressure is 200 torr. Specifically, when growing the Ga2O3 layer, O2 is introduced as the O source, TEGa is introduced as the Ga source, and the carrier gas used during growth is N2. When growing the MgGaN layer, NH3 is introduced as the N source, CP2Mg is introduced as the Mg source, TEGa is introduced as the Ga source, and the carrier gas used during growth is N2.

[0127] (7) Grow a P-type semiconductor layer on the electron blocking layer;

[0128] Specifically, grow a P-type semiconductor layer in MOCVD, the growth temperature is 900 °C, and the growth pressure is 200 torr. When growing, NH3 is introduced into the MOCVD reaction chamber as the N source, Cp2Mg is introduced as the P-type doping source; H2 and N2 are used as the carrier gases, and TMGa is introduced as the Ga source.

[0129] Example 3

[0130] This example provides a light-emitting diode epitaxial wafer. Refer to Figures 1 - 4 , which includes a substrate 1, a nucleation layer 2, an intrinsic GaN layer 3, an N-type semiconductor layer 4, a multi-quantum well layer 5, an electron blocking layer 6, and a P-type semiconductor layer 7 sequentially disposed on the substrate 1.

[0131] Among them, the substrate 1 is a sapphire substrate; the nucleation layer 2 is an AlGaN layer with a thickness of 30 nm; the thickness of the intrinsic GaN layer 3 is 400 nm; the doping concentration of Si in the N-type semiconductor layer 4 is 7×10 18 cm -3 , and its thickness is 2 μm. The multi-quantum well layer 5 is an alternately stacked InGaN quantum well layer and GaN quantum barrier layer, with a stacking period number of 10. The thickness of a single InGaN quantum well layer is 3 nm, and the thickness of a single GaN quantum barrier layer is 10 nm.

[0132] Among them, the electron blocking layer 6 includes a first sub-layer 61 and a second sub-layer 62 stacked in sequence. Among them, the first sub-layer 61 is a MgInGaN layer 611. The proportion of In component in the MgInGaN layer 611 gradually decreases from 0.3 to 0 along the epitaxial growth direction, and the doping concentration of Mg is 5×10 15 cm -3 , and its thickness is 15 nm. The In source in the MgInGaN layer 611 is intermittently introduced, where the interruption time is 3 s and the introduction time is 8 s; the Ga source in the MgInGaN layer is intermittently introduced. When the In source is interrupted, the Ga source is introduced, and the introduction time of the Ga source is 3 s; when the In source is introduced, the Ga source is interrupted, and the interruption time of the Ga source is 8 s.

[0133] Among them, the second sub-layer 62 includes a Ga2O3 layer 621 and a MgGaN layer 622 stacked in sequence. Among them, the thickness of the Ga2O3 layer 621 is 50 nm. The doping concentration of Mg in the MgGaN layer 622 is 5×10 17 cm -3 , and its thickness is 20 nm.

[0134] The doping element of the P-type semiconductor layer 7 is Mg, and the doping concentration is 3.5×10 19 cm -3 , and the thickness is 10 nm.

[0135] The preparation method of the light-emitting diode epitaxial wafer in this example includes the following steps:

[0136] (1) Provide a substrate; load the substrate into MOCVD and anneal it for 6 min at 1120 °C, 400 torr, and in a hydrogen atmosphere.

[0137] (2) Grow a nucleation layer on the substrate;

[0138] Specifically, grow an AlGaN layer by MOCVD, with a growth temperature of 620 °C and a growth pressure of 250 torr. During growth, introduce NH3 as the N source into the MOCVD reaction chamber; use H2 and N2 as carrier gases, introduce TMAl as the Al source, and introduce TMGa as the Ga source.

[0139] (3) Grow an intrinsic GaN layer on the nucleation layer;

[0140] Specifically, grow an intrinsic GaN layer by MOCVD, with a growth temperature of 1100 °C and a growth pressure of 250 torr. During growth, introduce NH3 as the N source into the MOCVD reaction chamber; use H2 and N2 as carrier gases, and introduce TMGa as the Ga source.

[0141] (4) Grow an N-type semiconductor layer on the intrinsic GaN layer;

[0142] Specifically, grow an N-type semiconductor layer by MOCVD, with a growth temperature of 1120 °C and a growth pressure of 150 torr; during growth, introduce NH3 as the N source into the MOCVD reaction chamber, introduce SiH4 as the N-type doping source; use H2 and N2 as carrier gases, and introduce TMGa as the Ga source.

[0143] (5) Grow a multi-quantum well layer on the N-type semiconductor layer;

[0144] Specifically, grow quantum well layers and quantum barrier layers periodically in MOCVD to obtain a multi-quantum well layer;

[0145] Among them, the growth temperature of the quantum well layer is 750 °C, the growth pressure is 300 torr. During growth, introduce NH3 as the N source into the MOCVD reaction chamber, use N2 as the carrier gas, introduce TEGa as the Ga source, and introduce TMIn as the In source; among them, the growth temperature of the quantum barrier layer is 820 °C, the growth pressure is 300 torr. During growth, introduce NH3 as the N source into the MOCVD reaction chamber, use H2 and N2 as carrier gases, and introduce TEGa as the Ga source.

[0146] (6) Grow an electron blocking layer on the multi-quantum well layer;

[0147] Specifically, the preparation method of each electron blocking layer includes:

[0148] (Ⅰ) Grow a first sub-layer on the multi-quantum well layer;

[0149] Specifically, a MgInGaN layer is grown in MOCVD as the first sub-layer. The growth temperature of the first sub-layer is gradually increased from 780 °C to 880 °C, the growth pressure is 200 torr, NH3 is introduced as the N source, CP2Mg is introduced as the Mg source, TMIn is introduced as the In source, TEGa is introduced as the Ga source, and the carrier gas used during growth is N2. The In source and Ga source are introduced intermittently. When the In source is interrupted, the Ga source is introduced, and the introduction time of the Ga source is the same as the interruption time of the In source; when the In source is introduced, the Ga source is interrupted, and the interruption time of the Ga source is the same as the introduction time of the In source.

[0150] (II) A second sub-layer is grown on the first sub-layer;

[0151] Specifically, a Ga2O3 layer and a MgGaN layer are sequentially stacked and grown in MOCVD as the second sub-layer. The growth temperature of the second sub-layer is 980 °C, and the growth pressure is 200 torr. Specifically, when growing the Ga2O3 layer, O2 is introduced as the O source, TEGa is introduced as the Ga source, and the carrier gas used during growth is N2. When growing the MgGaN layer, NH3 is introduced as the N source, CP2Mg is introduced as the Mg source, TEGa is introduced as the Ga source, and the carrier gas used during growth is N2.

[0152] (7) A P-type semiconductor layer is grown on the electron blocking layer;

[0153] Specifically, a P-type semiconductor layer is grown in MOCVD. The growth temperature is 900 °C, and the growth pressure is 200 torr. During growth, NH3 is introduced as the N source into the MOCVD reaction chamber, and Cp2Mg is introduced as the P-type doping source; H2 and N2 are used as carrier gases, and TMGa is introduced as the Ga source.

[0154] Example 4

[0155] This example provides a light-emitting diode epitaxial wafer. Referring to Figure 1 、 Figure 2 、 Figure 3 、 Figure 5 , it includes a substrate 1 and a nucleation layer 2, an intrinsic GaN layer 3, an N-type semiconductor layer 4, a multi-quantum well layer 5, an electron blocking layer 6, and a P-type semiconductor layer 7 sequentially provided on the substrate 1.

[0156] Among them, the substrate 1 is a sapphire substrate; the nucleation layer 2 is an AlGaN layer with a thickness of 30 nm; the thickness of the intrinsic GaN layer 3 is 400 nm; the doping concentration of Si in the N-type semiconductor layer 4 is 7×10 18 cm -3, with a thickness of 2 μm. The multiple quantum well layer 5 is an alternately stacked InGaN quantum well layer and GaN quantum barrier layer, with 10 stacking periods. The thickness of a single InGaN quantum well layer is 3 nm, and the thickness of a single GaN quantum barrier layer is 10 nm.

[0157] Among them, the electron blocking layer 6 includes a first sub-layer 61 and a second sub-layer 62 stacked in sequence. Among them, the first sub-layer 61 is a MgInGaN layer 611. In the MgInGaN layer 611, the proportion of In component gradually decreases from 0.3 to 0 along the epitaxial growth direction, and the doping concentration of Mg is 5×10 15 cm -3 , with a thickness of 15 nm. In the MgInGaN layer 611, the In source is intermittently introduced. Among them, the interruption time is 3 s, and the introduction time is 8 s; the Ga source in the MgInGaN layer is intermittently introduced. When the In source is interrupted, the Ga source is introduced, and the introduction time of the Ga source is 3 s; when the In source is introduced, the Ga source is interrupted, and the interruption time of the Ga source is 8 s.

[0158] Among them, the second sub-layer 62 includes a Ga2O3 layer 621 and a MgGaN layer 622 stacked periodically in sequence, with 6 periods. Among them, the thickness of a single Ga2O3 layer 621 is 10 nm. The thickness of a single MgGaN layer 622 is 5 nm, and the doping concentration of Mg is 5×10 17 cm -3 .

[0159] The doping element of the P-type semiconductor layer 7 is Mg, and the doping concentration is 3.5×10 19 cm -3 , with a thickness of 10 nm.

[0160] The preparation method of the light-emitting diode epitaxial wafer in this embodiment includes the following steps:

[0161] (1) Provide a substrate; load the substrate into MOCVD and anneal it for 6 min at 1120 °C, 400 torr, and in a hydrogen atmosphere.

[0162] (2) Grow a nucleation layer on the substrate;

[0163] Specifically, grow an AlGaN layer by MOCVD, with a growth temperature of 620 °C and a growth pressure of 250 torr. During growth, introduce NH3 as the N source into the MOCVD reaction chamber; use H2 and N2 as carrier gases, introduce TMAl as the Al source, and introduce TMGa as the Ga source.

[0164] (3) Grow an intrinsic GaN layer on the nucleation layer;

[0165] Specifically, an intrinsic GaN layer is grown by MOCVD at a growth temperature of 1100 °C and a growth pressure of 250 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source; H2 and N2 are used as carrier gases, and TMGa is introduced as the Ga source.

[0166] (4) An N-type semiconductor layer is grown on the intrinsic GaN layer;

[0167] Specifically, an N-type semiconductor layer is grown by MOCVD at a growth temperature of 1120 °C and a growth pressure of 150 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source, and SiH4 is introduced as the N-type doping source; H2 and N2 are used as carrier gases, and TMGa is introduced as the Ga source.

[0168] (5) A multi-quantum well layer is grown on the N-type semiconductor layer;

[0169] Specifically, the quantum well layer and the quantum barrier layer are periodically grown in MOCVD to obtain a multi-quantum well layer;

[0170] Among them, the growth temperature of the quantum well layer is 750 °C, and the growth pressure is 300 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source, N2 is used as the carrier gas, TEGa is introduced as the Ga source, and TMIn is introduced as the In source; among them, the growth temperature of the quantum barrier layer is 820 °C, and the growth pressure is 300 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source, H2 and N2 are used as the carrier gases, and TEGa is introduced as the Ga source.

[0171] (6) An electron blocking layer is grown on the multi-quantum well layer;

[0172] Specifically, the preparation method of each electron blocking layer includes:

[0173] (Ⅰ) A first sub-layer is grown on the multi-quantum well layer;

[0174] Specifically, a MgInGaN layer is grown in MOCVD as the first sub-layer. The growth temperature of the first sub-layer gradually increases from 780 °C to 880 °C, the growth pressure is 200 torr, NH3 is introduced as the N source, CP2Mg is introduced as the Mg source, TMIn is introduced as the In source, TEGa is introduced as the Ga source, and the carrier gas used during growth is N2. The In source and the Ga source are intermittently introduced. When the In source is interrupted, the Ga source is introduced, and the introduction time of the Ga source is the same as the interruption time of the In source; when the In source is introduced, the Ga source is interrupted, and the interruption time of the Ga source is the same as the introduction time of the In source.

[0175] (Ⅱ) A second sub-layer is grown on the first sub-layer;

[0176] Specifically, in MOCVD, the Ga2O3 layer and the MgGaN layer are periodically stacked as the second sublayer. The growth temperature of the second sublayer is 980 °C, and the growth pressure is 200 torr. Specifically, when growing the Ga2O3 layer, O2 is introduced as the O source, and TEGa is introduced as the Ga source. The carrier gas used during growth is N2. When growing the MgGaN layer, NH3 is introduced as the N source, CP2Mg is introduced as the Mg source, and TEGa is introduced as the Ga source. The carrier gas used during growth is N2.

[0177] (7) A P-type semiconductor layer is grown on the electron blocking layer;

[0178] Specifically, in MOCVD, the P-type semiconductor layer is grown at a growth temperature of 900 °C and a growth pressure of 200 torr. During growth, NH3 is introduced into the MOCVD reaction chamber as the N source, and Cp2Mg is introduced as the P-type doping source; H2 and N2 are used as the carrier gases, and TMGa is introduced as the Ga source.

[0179] Comparative Example 1

[0180] This comparative example provides a light-emitting diode epitaxial wafer, which is different from Example 1 in that the electron blocking layer 6 in the epitaxial wafer is an AlGaN layer, the proportion of Al component in the AlGaN layer is 0.6, and its thickness is 50 nm. Correspondingly, in the preparation method, the growth temperature of the AlGaN layer is 980 °C, the growth pressure is 200 torr, and the rest are the same as in Example 1.

[0181] Comparative Example 2

[0182] This comparative example provides a light-emitting diode epitaxial wafer, which is different from Example 1 in that the electron blocking layer 6 in the epitaxial wafer is an Al a Ga 1-a N layer (a = 0.12) and an In b Ga 1-b N layer (b = 0.3) with an alternately grown periodic structure, the number of periods is 8, the thickness of a single Al a Ga 1-a N layer is 5 nm, and the thickness of a single In b Ga 1-b N layer is 1 nm. Correspondingly, in the preparation method, the growth temperature of the electron blocking layer 6 is 980 °C, the growth pressure is 200 torr, and the rest are the same as in Example 1.

[0183] Comparative Example 3

[0184] This comparative example provides a light-emitting diode epitaxial wafer, which is different from Example 1 in that the electron blocking layer 6 does not include the second sublayer 62. Correspondingly, in the preparation method, the preparation step of this layer is not set either, and the rest are the same as in Example 1.

[0185] Comparative Example 4

[0186] This comparative example provides a light-emitting diode epitaxial wafer, which is different from that of Example 1 in that the electron blocking layer 6 does not include the first sub-layer 61. Correspondingly, in the preparation method, the preparation step of this layer is not set either, and the rest are the same as those of Example 1.

[0187] Comparative Example 5

[0188] This comparative example provides a light-emitting diode epitaxial wafer, which is different from that of Example 1 in that the electron blocking layer 6 does not include the Ga2O3 layer 621. Correspondingly, in the preparation method, the preparation step of this layer is not set either, and the rest are the same as those of Example 1.

[0189] The light-emitting diode epitaxial wafers obtained in Examples 1-4 and Comparative Examples 1-5 were tested for brightness and operating voltage. The specific test methods are as follows:

[0190] (1) Prepare the epitaxial wafer into a chip with a vertical structure of 10 mil × 24 mil and test its luminous brightness;

[0191] (2) Operating voltage: Use a Keithley 2450 digital source meter to test the operating voltage.

[0192] The specific results are as follows:

[0193] Luminance (mW) Operating voltage (V) Example 1 194.3 3.14 Example 2 195.1 3.13 Example 3 195.5 3.11 Example 4 196.8 3.09 Comparative Example 1 190.6 3.23 Comparative Example 2 192.1 3.21 Comparative Example 3 192.2 3.19 Comparative Example 4 192.7 3.18 Comparative Example 5 193.1 3.18

[0194] It can be seen from the table that when the traditional electron blocking layer (Comparative Example 1) is changed to the electron blocking layer structure in the present invention, the brightness is increased from 190.6 mW to 194.3 mW, and the operating voltage is decreased from 3.23 V to 3.14 V, indicating that the electron blocking layer in the present invention can effectively improve the brightness and reduce the operating voltage. In addition, through the comparison between Example 1 and Comparative Examples 2-5, it can be seen that when the electron blocking layer structure in the present invention is changed, it is difficult to effectively improve the brightness and reduce the operating voltage.

[0195] The above is the preferred embodiment 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 comprising a substrate and a nucleation layer, an intrinsic GaN layer, an N-type semiconductor layer, a multi-quantum well layer, an electron blocking layer, and a P-type semiconductor layer sequentially disposed on the substrate; characterized in that: The electron blocking layer includes a first sublayer and a second sublayer stacked in sequence; Wherein, the first sublayer is a MgInGaN layer; the proportion of In component in the MgInGaN layer gradually decreases from 0.2-0.4 to 0 along the epitaxial growth direction; The second sublayer includes a Ga2O3 layer and a MgGaN layer stacked in sequence; it is a periodic structure with a period number of 3-10; wherein the thickness of a single Ga2O3 layer is 5nm-20nm; the thickness of a single MgGaN layer is 1nm-5nm.

2. The light emitting diode epitaxial wafer according to claim 1, wherein: The Mg doping concentration in the MgInGaN layer is 1×10 15 cm -3 -1×10 16 cm -3 , the thickness of the MgInGaN layer is 5nm-50nm.

3. The light emitting diode epitaxial wafer according to claim 1, wherein: The Mg doping concentration of the MgGaN layer is 1×10 17 cm -3 -1×10 18 cm -3 .

4. A method for preparing a light-emitting diode epitaxial wafer, for preparing the light-emitting diode epitaxial wafer according to any one of claims 1 to 3, characterized in that: include: Providing a substrate, and sequentially growing a nucleation layer, an intrinsic GaN layer, an N-type semiconductor layer, a multi-quantum well layer, an electron blocking layer, and a P-type semiconductor layer on the substrate; the electron blocking layer includes a first sublayer and a second sublayer stacked in sequence; Wherein, the first sub-layer is a MgInGaN layer; The second sublayer includes a Ga2O3 layer and a MgGaN layer stacked in sequence.

5. The method for preparing a light emitting diode epitaxial wafer according to claim 4, wherein: The In source in the MgInGaN layer is intermittently introduced, wherein the interruption time is 1s-5s and the introduction time is 5s-10s; The Ga source in the MgInGaN layer is intermittently introduced. When the In source is interrupted, the Ga source is introduced, and the Ga source introduction time is the same as the In source interruption time; when the In source is introduced, the Ga source is interrupted, and the Ga source interruption time is the same as the In source introduction time.

6. The method for preparing a light emitting diode epitaxial wafer according to claim 4, wherein: The growth temperature of the first sub-layer is gradually increased from 750°C to 800°C to 850°C to 900°C, and the growth pressure is 100 torr to 300 torr; The growth temperature of the second sub-layer is 950° C.-1000° C., and the growth pressure is 100 torr-300 torr.

7. The method for preparing a light emitting diode epitaxial wafer according to claim 4, wherein: The carrier gas used in the growth of the first sub-layer and the second sub-layer is N2.

8. A light emitting diode, characterized in that: It comprises the light emitting diode epitaxial wafer as described in any one of claims 1 to 3.

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