Light emitting diode epitaxial wafer and preparation method thereof, LED

Abstract

The present invention relates to the field of optoelectronics, and discloses a light-emitting diode epitaxial wafer, a method for manufacturing the same, and an LED. The light-emitting diode epitaxial wafer comprises a substrate, on which a buffer layer, an undoped GaN layer, an N-type GaN layer, an active layer, an electron blocking layer, and a P-type GaN layer are sequentially provided; the electron blocking layer comprises a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer, and a BN layer stacked in sequence. The light-emitting diode epitaxial wafer provided by the present invention reduces electron overflow, improves hole injection efficiency, replenishes hole concentration, and enhances the luminous efficiency of the light-emitting diode.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic technology, and in particular to a light emitting diode epitaxial wafer and a preparation method thereof, and an LED. Background Art

[0002] The mobility of electrons in the GaN material system is much greater than the mobility of holes. Under high current density, the active region's ability to restrict electrons is weakened. Some electrons can pass through the active region from the N-type side to the P-type side, causing electron leakage. The matching degree between electrons and holes in the active region decreases, resulting in a decrease in the efficiency of the LED device. In order to better confine electrons in the active region, an AlGaN layer with a larger bandgap width is grown after the active layer is grown as an electron blocking layer to effectively inhibit electrons from passing through the active region. Due to the high AlGaN barrier, while blocking electrons from leaking into the P layer, it also blocks holes from being injected into the active region, reducing the hole injection efficiency and the luminous efficiency of the light-emitting diode. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a light-emitting diode epitaxial wafer, which reduces electron overflow, improves hole injection efficiency, replenishes hole concentration, and improves the luminous efficiency of the light-emitting diode.

[0004] The technical problem to be solved by the present invention is to provide a method for preparing a light-emitting diode epitaxial wafer, which has a simple process and can stably produce a light-emitting diode epitaxial wafer with good luminous efficiency.

[0005] In order to solve the above technical problems, the present invention provides a light-emitting diode epitaxial wafer, comprising a substrate, on which a buffer layer, an undoped GaN layer, an N-type GaN layer, an active layer, an electron blocking layer, and a P-type GaN layer are sequentially provided;

[0006] The electron blocking layer includes a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer, and a BN layer which are stacked in sequence.

[0007] In some embodiments, the BAlN / P-GaN superlattice layer includes BAlN layers and P-GaN layers stacked alternately, with the alternating period number being 1 to 10;

[0008] The thickness of the BAlN / P-GaN superlattice layer is 1 nm to 50 nm.

[0009] In some embodiments, the thickness ratio of the BAlN layer to the P-GaN layer is 1:(1-10);

[0010] The B component of the BAlN layer is 0.01 to 0.1;

[0011] The Mg doping concentration of the P-GaN layer is 1×10 17 atoms / cm 3 ~1×10 18 atoms / cm 3 .

[0012] In some embodiments, the AlGaN / P-InGaN superlattice layer comprises alternately stacked AlGaN / and P-InGaN layers, with the number of alternating periods being 1 to 20;

[0013] The thickness of the AlGaN / P-InGaN superlattice layer is 1 nm to 50 nm.

[0014] In some embodiments, the thickness ratio of the AlGaN layer to the P-InGaN layer is (1-5):1;

[0015] The Al composition of the AlGaN layer is 0.01 to 0.1;

[0016] The Mg doping concentration of the P-InGaN layer is 1×10 18 atoms / cm 3 ~1×10 19 atoms / cm 3 .

[0017] In some embodiments, the BN layer has a thickness of 0.1 nm to 10 nm.

[0018] To solve the above problems, the present invention further provides a method for preparing a light-emitting diode epitaxial wafer, comprising the following steps:

[0019] S1. providing a substrate;

[0020] S2. Depositing a buffer layer, an undoped GaN layer, an N-type GaN layer, an active layer, an electron blocking layer, and a P-type GaN layer on the substrate in sequence;

[0021] The electron blocking layer includes a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer, and a BN layer which are stacked in sequence.

[0022] In some embodiments, the growth temperature of the BAlN / P-GaN superlattice layer is 900° C. to 1000° C., and the growth pressure is 50 torr to 500 torr;

[0023] The growth temperature of the AlGaN / P-InGaN superlattice layer is 900° C. to 1000° C., and the growth pressure is 50 torr to 500 torr;

[0024] The growth temperature of the BN layer is 900° C. to 1000° C., and the growth pressure is 50 torr to 500 torr.

[0025] Correspondingly, the present invention further provides an LED, which includes the light emitting diode epitaxial wafer as described above.

[0026] The implementation of the present invention has the following beneficial effects:

[0027] The electron blocking layer of the present invention comprises a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer and a BN layer which are stacked in sequence.

[0028] In the BAlN / P-GaN superlattice, the BAlN layer, due to its high potential barrier, blocks electrons from flowing to the P-type GaN layer, resulting in non-radiative recombination. The deposited P-GaN layer increases hole diffusion into the active layer. The multiple blocking and hole expansion effects of the superlattice structure effectively reduce electron overflow and improve hole injection efficiency.

[0029] In the AlGaN / P-InGaN superlattice layer, the AlGaN layer has a high potential barrier, which again blocks electrons from leaking into the P-type GaN layer. The P-InGaN layer generates holes to supplement the number of holes in the epitaxial layer. Its superlattice structure effectively inhibits electrons from passing through the active region, thereby increasing the hole concentration injected from the P-type GaN layer into the active layer.

[0030] The BN layer reduces the extension of line defects of the epitaxial layer to the P-type GaN layer, improves the crystal quality of the subsequently deposited P-type GaN layer, and reduces leakage of the light-emitting diode.

[0031] As described above, the electron blocking layer of the present invention reduces electron overflow, improves hole injection efficiency, replenishes hole concentration, and enhances the luminous efficiency of the light-emitting diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a structural schematic diagram of the light emitting diode epitaxial wafer provided by the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and are not to be construed as limiting the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0034] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of the described features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0036] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections, or mutual communication; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0037] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0038] The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those skilled in the art will appreciate the application of other processes and / or the use of other materials.

[0039] In the present invention, the terms "preferred" and "better" are merely used to describe preferred implementation methods or examples and should be understood not to limit the scope of protection of the present invention. In the present invention, technical features described as open-ended include both closed-ended technical solutions consisting of the listed features and open-ended technical solutions containing the listed features. In the present invention, references to numerical ranges include both endpoints of the numerical range unless otherwise specified.

[0040] In order to solve the above problems, the present invention provides a light emitting diode epitaxial wafer, such as Figure 1 As shown, it includes a substrate 100, on which a buffer layer 200, an undoped GaN layer 300, an N-type GaN layer 400, an active layer 500, an electron blocking layer 600, and a P-type GaN layer 700 are sequentially provided;

[0041] The electron blocking layer 600 includes a BAlN / P-GaN superlattice layer 610 , an AlGaN / P-InGaN superlattice layer 620 , and a BN layer 630 , which are stacked in sequence.

[0042] The specific structure of the electron blocking layer 600 provided by the present invention is as follows:

[0043] In some embodiments, the BAlN / P-GaN superlattice layer 610 includes alternating BAlN layers and P-GaN layers, with an alternating period of 1 to 10. Exemplary alternating periods are 2, 3, 4, 5, 6, 7, 8, and 9, but are not limited to the above.

[0044] In some embodiments, the thickness of the BAlN / P-GaN superlattice layer 610 is 1 nm to 50 nm. Exemplary thicknesses of the BAlN / P-GaN superlattice layer 610 are 5 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, and 45 nm, but are not limited to the above.

[0045] In some embodiments, the thickness ratio of the BAlN layer to the P-GaN layer is 1:(1-10); preferably, the thickness ratio of the BAlN layer to the P-GaN layer is 1:(2-8).

[0046] In some embodiments, the B component of the BAlN layer is 0.01 to 0.1; preferably, the B component of the BAlN layer is 0.02 to 0.09.

[0047] In some embodiments, the Mg doping concentration of the P-GaN layer is 1×10 17 atoms / cm 3 ~1×10 18 atoms / cm 3 The exemplary Mg doping concentration of the P-GaN layer is 2×10 17 atoms / cm 3 , 3×10 17 atoms / cm 3 , 4×10 17 atoms / cm 3 , 5×10 17 atoms / cm 3 , 6×10 17 atoms / cm 3 , 7×10 17 atoms / cm 3 , 8×10 17 atoms / cm 3 , 9×10 17 atoms / cm 3 , but not limited to the above enumeration.

[0048] In the BAlN / P-GaN superlattice, the BAlN layer, due to its high potential barrier, blocks electrons from flowing to the P-type GaN layer, resulting in non-radiative recombination. The deposited P-GaN layer increases hole diffusion into the active layer. The multiple blocking and hole expansion effects of the superlattice structure effectively reduce electron overflow and improve hole injection efficiency.

[0049] In some embodiments, the AlGaN / P-InGaN superlattice layer 620 includes alternating stacked AlGaN / and P-InGaN layers, with an alternating period number of 1 to 20; exemplary alternating period numbers are 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, and 19, but are not limited to the above.

[0050] In some embodiments, the AlGaN / P-InGaN superlattice layer 620 has a thickness of 1 nm to 50 nm. Exemplary thicknesses of the AlGaN / P-InGaN superlattice layer 620 are 5 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, and 45 nm, but are not limited to the above.

[0051] In some embodiments, the thickness ratio of the AlGaN layer to the P-InGaN layer is (1-5):1; preferably, the thickness ratio of the AlGaN layer to the P-InGaN layer is (2-4):1.

[0052] In some embodiments, the Al composition of the AlGaN layer is 0.01 to 0.1; preferably, the Al composition of the AlGaN layer is 0.02 to 0.08;

[0053] In some embodiments, the Mg doping concentration of the P-InGaN layer is 1×10 18 atoms / cm 3 ~1×10 19 atoms / cm 3 The exemplary Mg doping concentration of the P-InGaN layer is 2×10 18 atoms / cm 3 , 3×10 18 atoms / cm 3 , 4×10 18 atoms / cm 3 , 5×10 18 atoms / cm 3 , 6×10 18 atoms / cm 3 , 7×10 18 atoms / cm 3 , 8×10 18 atoms / cm 3 , 9×10 18 atoms / cm 3 , but not limited to the above enumeration.

[0054] In the AlGaN / P-InGaN superlattice layer, the AlGaN layer has a high potential barrier, which again blocks electrons from leaking into the P-type GaN layer. The P-InGaN layer generates holes to supplement the number of holes in the epitaxial layer. Its superlattice structure effectively inhibits electrons from passing through the active region, thereby increasing the hole concentration injected from the P-type GaN layer into the active layer.

[0055] In some embodiments, the thickness of the BN layer 630 is 0.1 nm to 10 nm. Exemplary thicknesses of the BN layer 630 include, but are not limited to, 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, and 9 nm. The BN layer reduces the extension of line defects in the epitaxial layer into the P-type GaN layer, thereby improving the crystal quality of the subsequently deposited P-type GaN layer and reducing leakage in the light-emitting diode.

[0056] In summary, the present invention improves the crystal quality of the GaN epitaxial layer, reduces the non-radiative recombination efficiency of the quantum well, and improves the luminous efficiency of the light-emitting diode.

[0057] Accordingly, the present invention provides a method for preparing a light-emitting diode epitaxial wafer, comprising the following steps:

[0058] S1, providing a substrate 100;

[0059] In some embodiments, substrate 100 may be a sapphire substrate, a SiO2-sapphire composite substrate, a silicon substrate, a silicon carbide substrate, a gallium nitride substrate, or a zinc oxide substrate. Preferably, substrate 100 is a sapphire substrate, which is a commonly used GaN-based LED substrate material. Sapphire substrates have mature manufacturing processes, are relatively inexpensive, are easy to clean and handle, and exhibit excellent stability at high temperatures.

[0060] S2, depositing a buffer layer 200, an undoped GaN layer 300, an N-type GaN layer 400, an active layer 500, an electron blocking layer 600, and a P-type GaN layer 700 in sequence on the substrate 100;

[0061] The electron blocking layer 600 includes a BAlN / P-GaN superlattice layer 610 , an AlGaN / P-InGaN superlattice layer 620 , and a BN layer 630 , which are stacked in sequence.

[0062] Specifically, the above step S2 specifically includes the following steps:

[0063] S21 , depositing the buffer layer 200 on the substrate 100 .

[0064] In some embodiments, the buffer layer 200 is an AlN buffer layer.

[0065] S22 , depositing the undoped GaN layer 300 on the buffer layer 200 .

[0066] In some embodiments, the temperature of the reaction chamber is controlled at 1050° C. to 1200° C., the pressure is controlled at 100 torr to 600 torr, an N source and a Ga source are introduced, and an undoped GaN layer with a thickness of 1 μm to 5 μm is grown.

[0067] S23 , depositing the N-type GaN layer 400 on the undoped GaN layer 300 .

[0068] In some embodiments, the temperature of the reaction chamber is controlled at 1050° C. to 1200° C., the pressure is controlled at 100 torr to 600 torr, and an N source, a Ga source, and a Si source are introduced to grow the N-type GaN layer.

[0069] S24 , depositing the active layer 500 on the N-type GaN layer 400 .

[0070] In some embodiments, the active layer is an alternately stacked InGaN quantum well layer and an AlGaN quantum barrier layer, with a stacking period of 1 to 20. The growth temperature of the InGaN quantum well layer is 750°C to 850°C, the thickness is 2nm to 5nm, and the growth pressure is 50torr to 300torr; the growth temperature of the AlGaN quantum barrier layer is 800°C to 900°C, the thickness is 5nm to 15nm, and the growth pressure is 50torr to 300torr.

[0071] S25, depositing the electron blocking layer 600 on the active layer 500;

[0072] In some embodiments, the growth temperature of the BAlN / P-GaN superlattice layer 610 is 900° C. to 1000° C., and the growth pressure is 50 torr to 500 torr;

[0073] The AlGaN / P-InGaN superlattice layer 620 has a growth temperature of 900° C. to 1000° C. and a growth pressure of 50 torr to 500 torr.

[0074] The BN layer 630 is grown at a temperature of 900° C. to 1000° C. and a pressure of 50 torr to 500 torr.

[0075] S26 , depositing the P-type GaN layer 700 on the electron blocking layer 600 .

[0076] In some embodiments, the temperature of the reaction chamber is controlled at 900° C. to 1050° C., the pressure is controlled at 100 torr to 600 torr, and an N source, a Mg source, and a Ga source are introduced to grow the P-type GaN layer.

[0077] Accordingly, the present invention further provides an LED comprising the above-mentioned light-emitting diode epitaxial wafer, wherein the photoelectric efficiency of the LED is effectively improved and other electrical properties are good.

[0078] The present invention is further described below with specific examples:

[0079] Example 1

[0080] This embodiment provides a light-emitting diode epitaxial wafer, comprising a substrate, on which a buffer layer, an undoped GaN layer, an N-type GaN layer, an active layer, an electron blocking layer, and a P-type GaN layer are sequentially provided;

[0081] The electron blocking layer includes a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer, and a BN layer which are stacked in sequence.

[0082] The BAlN / P-GaN superlattice layer includes BAlN layers and P-GaN layers alternately stacked, with an alternating period of 6. The thickness of the BAlN / P-GaN superlattice layer is 18 nm, and the thickness ratio of the BAlN layer to the P-GaN layer is 1:2. The B component of the BAlN layer is 0.05. The Mg doping concentration of the P-GaN layer is 6.5×10 17 atoms / cm 3 .

[0083] The AlGaN / P-InGaN superlattice layer includes alternately stacked AlGaN / and P-InGaN layers, with an alternating period of 5. The thickness of the AlGaN / P-InGaN superlattice layer is 15 nm, and the thickness ratio of the AlGaN layer to the P-InGaN layer is 2:1. The Al composition of the AlGaN layer is 0.06. The Mg doping concentration of the P-InGaN layer is 3.2×10 18 atoms / cm 3 .

[0084] The thickness of the BN layer is 2.8 nm.

[0085] Example 2

[0086] This embodiment provides a light-emitting diode epitaxial wafer, comprising a substrate, on which a buffer layer, an undoped GaN layer, an N-type GaN layer, an active layer, an electron blocking layer, and a P-type GaN layer are sequentially provided;

[0087] The electron blocking layer includes a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer, and a BN layer which are stacked in sequence.

[0088] The BAlN / P-GaN superlattice layer includes BAlN layers and P-GaN layers alternately stacked, with an alternating period of 21. The thickness of the BAlN / P-GaN superlattice layer is 18 nm, and the thickness ratio of the BAlN layer to the P-GaN layer is 1:2. The B component of the BAlN layer is 0.05. The Mg doping concentration of the P-GaN layer is 6.5×10 17 atoms / cm3 .

[0089] The AlGaN / P-InGaN superlattice layer includes alternately stacked AlGaN / and P-InGaN layers, with an alternating period of 5. The thickness of the AlGaN / P-InGaN superlattice layer is 18 nm, and the thickness ratio of the AlGaN layer to the P-InGaN layer is 2:1. The Al composition of the AlGaN layer is 0.06. The Mg doping concentration of the P-InGaN layer is 3.2×10 18 atoms / cm 3 .

[0090] The thickness of the BN layer is 3.5 nm.

[0091] Example 3

[0092] This embodiment provides a light-emitting diode epitaxial wafer, comprising a substrate, on which a buffer layer, an undoped GaN layer, an N-type GaN layer, an active layer, an electron blocking layer, and a P-type GaN layer are sequentially provided;

[0093] The electron blocking layer includes a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer, and a BN layer which are stacked in sequence.

[0094] The BAlN / P-GaN superlattice layer includes BAlN layers and P-GaN layers alternately stacked, with an alternating period of 6. The thickness of the BAlN / P-GaN superlattice layer is 12 nm, and the thickness ratio of the BAlN layer to the P-GaN layer is 1:2. The B component of the BAlN layer is 0.05. The Mg doping concentration of the P-GaN layer is 6.5×10 17 atoms / cm 3 .

[0095] The AlGaN / P-InGaN superlattice layer includes alternately stacked AlGaN / and P-InGaN layers, with an alternating period of 5. The thickness of the AlGaN / P-InGaN superlattice layer is 9 nm, and the thickness ratio of the AlGaN layer to the P-InGaN layer is 2:1. The Al composition of the AlGaN layer is 0.06; the Mg doping concentration of the P-InGaN layer is 3.2×10 18 atoms / cm 3 .

[0096] The thickness of the BN layer is 2.1 nm.

[0097] Example 4

[0098] This embodiment provides a light-emitting diode epitaxial wafer, comprising a substrate, on which a buffer layer, an undoped GaN layer, an N-type GaN layer, an active layer, an electron blocking layer, and a P-type GaN layer are sequentially provided;

[0099] The electron blocking layer includes a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer, and a BN layer which are stacked in sequence.

[0100] The BAlN / P-GaN superlattice layer includes BAlN layers and P-GaN layers alternately stacked, with an alternating period of 8. The thickness of the BAlN / P-GaN superlattice layer is 18 nm, and the thickness ratio of the BAlN layer to the P-GaN layer is 1:3. The B component of the BAlN layer is 0.05. The Mg doping concentration of the P-GaN layer is 6.5×10 17 atoms / cm 3 .

[0101] The AlGaN / P-InGaN superlattice layer includes alternately stacked AlGaN / and P-InGaN layers, with an alternating period of 7. The thickness of the AlGaN / P-InGaN superlattice layer is 15 nm, and the thickness ratio of the AlGaN layer to the P-InGaN layer is 3:1. The Al composition of the AlGaN layer is 0.06. The Mg doping concentration of the P-InGaN layer is 3.2×10 18 atoms / cm 3 .

[0102] The thickness of the BN layer is 2.8 nm.

[0103] Example 5

[0104] This embodiment provides a light-emitting diode epitaxial wafer, comprising a substrate, on which a buffer layer, an undoped GaN layer, an N-type GaN layer, an active layer, an electron blocking layer, and a P-type GaN layer are sequentially provided;

[0105] The electron blocking layer includes a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer, and a BN layer which are stacked in sequence.

[0106] The BAlN / P-GaN superlattice layer includes BAlN layers and P-GaN layers alternately stacked, with an alternating period of 3. The thickness of the BAlN / P-GaN superlattice layer is 18 nm, and the thickness ratio of the BAlN layer to the P-GaN layer is 1:1. The B component of the BAlN layer is 0.05; the Mg doping concentration of the P-GaN layer is 6.5×10 17 atoms / cm 3 .

[0107] The AlGaN / P-InGaN superlattice layer includes alternately stacked AlGaN / and P-InGaN layers, with an alternating period of 2. The thickness of the AlGaN / P-InGaN superlattice layer is 15 nm, and the thickness ratio of the AlGaN layer to the P-InGaN layer is 1:1. The Al composition of the AlGaN layer is 0.06; the Mg doping concentration of the P-InGaN layer is 3.2×10 18 atoms / cm 3 .

[0108] The thickness of the BN layer is 2.8 nm.

[0109] Example 6

[0110] This embodiment provides a light-emitting diode epitaxial wafer, comprising a substrate, on which a buffer layer, an undoped GaN layer, an N-type GaN layer, an active layer, an electron blocking layer, and a P-type GaN layer are sequentially provided;

[0111] The electron blocking layer includes a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer, and a BN layer which are stacked in sequence.

[0112] The BAlN / P-GaN superlattice layer includes BAlN layers and P-GaN layers alternately stacked, with an alternating period of 6. The thickness of the BAlN / P-GaN superlattice layer is 18 nm, and the thickness ratio of the BAlN layer to the P-GaN layer is 1:2. The B component of the BAlN layer is 0.03. The Mg doping concentration of the P-GaN layer is 6.5×10 17 atoms / cm 3 .

[0113] The AlGaN / P-InGaN superlattice layer includes alternately stacked AlGaN / and P-InGaN layers, with an alternating period of 5. The thickness of the AlGaN / P-InGaN superlattice layer is 15 nm, and the thickness ratio of the AlGaN layer to the P-InGaN layer is 2:1. The Al composition of the AlGaN layer is 0.05; the Mg doping concentration of the P-InGaN layer is 3.2×10 18 atoms / cm 3 .

[0114] The thickness of the BN layer is 2.8 nm.

[0115] Example 7

[0116] This embodiment provides a light-emitting diode epitaxial wafer, comprising a substrate, on which a buffer layer, an undoped GaN layer, an N-type GaN layer, an active layer, an electron blocking layer, and a P-type GaN layer are sequentially provided;

[0117] The electron blocking layer includes a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer, and a BN layer which are stacked in sequence.

[0118] The BAlN / P-GaN superlattice layer includes BAlN layers and P-GaN layers alternately stacked, with an alternating period of 6. The thickness of the BAlN / P-GaN superlattice layer is 18 nm, and the thickness ratio of the BAlN layer to the P-GaN layer is 1:2. The B component of the BAlN layer is 0.07. The Mg doping concentration of the P-GaN layer is 6.5×10 17 atoms / cm 3 .

[0119] The AlGaN / P-InGaN superlattice layer includes alternately stacked AlGaN / and P-InGaN layers, with an alternating period of 5. The thickness of the AlGaN / P-InGaN superlattice layer is 15 nm, and the thickness ratio of the AlGaN layer to the P-InGaN layer is 2:1. The Al composition of the AlGaN layer is 0.08; the Mg doping concentration of the P-InGaN layer is 3.2×10 18 atoms / cm 3 .

[0120] The thickness of the BN layer is 2.8 nm.

[0121] Example 8

[0122] This embodiment provides a light-emitting diode epitaxial wafer, comprising a substrate, on which a buffer layer, an undoped GaN layer, an N-type GaN layer, an active layer, an electron blocking layer, and a P-type GaN layer are sequentially provided;

[0123] The electron blocking layer includes a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer, and a BN layer which are stacked in sequence.

[0124] The BAlN / P-GaN superlattice layer includes BAlN layers and P-GaN layers alternately stacked, with an alternating period of 6. The thickness of the BAlN / P-GaN superlattice layer is 18 nm, and the thickness ratio of the BAlN layer to the P-GaN layer is 1:2. The B component of the BAlN layer is 0.05. The Mg doping concentration of the P-GaN layer is 8×10 17 atoms / cm 3 .

[0125] The AlGaN / P-InGaN superlattice layer includes alternately stacked AlGaN / and P-InGaN layers, with an alternating period of 5. The thickness of the AlGaN / P-InGaN superlattice layer is 15 nm, and the thickness ratio of the AlGaN layer to the P-InGaN layer is 2:1. The Al composition of the AlGaN layer is 0.06; the Mg doping concentration of the P-InGaN layer is 5×10 18 atoms / cm 3 .

[0126] The thickness of the BN layer is 2.8 nm.

[0127] Example 9

[0128] This embodiment provides a light-emitting diode epitaxial wafer, comprising a substrate, on which a buffer layer, an undoped GaN layer, an N-type GaN layer, an active layer, an electron blocking layer, and a P-type GaN layer are sequentially provided;

[0129] The electron blocking layer includes a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer, and a BN layer which are stacked in sequence.

[0130] The BAlN / P-GaN superlattice layer includes BAlN layers and P-GaN layers alternately stacked, with an alternating period of 6. The thickness of the BAlN / P-GaN superlattice layer is 18 nm, and the thickness ratio of the BAlN layer to the P-GaN layer is 1:2. The B component of the BAlN layer is 0.05. The Mg doping concentration of the P-GaN layer is 5×10 17 atoms / cm 3 .

[0131] The AlGaN / P-InGaN superlattice layer includes alternately stacked AlGaN / and P-InGaN layers, with an alternating period of 5. The thickness of the AlGaN / P-InGaN superlattice layer is 15 nm, and the thickness ratio of the AlGaN layer to the P-InGaN layer is 2:1. The Al composition of the AlGaN layer is 0.06; the Mg doping concentration of the P-InGaN layer is 2×10 18 atoms / cm 3 .

[0132] The thickness of the BN layer is 2.8 nm.

[0133] Comparative Example 1

[0134] This comparative example provides a light emitting diode epitaxial wafer. The difference between the comparative example and the first embodiment is that the electron blocking layer is a 25 nm AlGaN electron blocking layer. The rest is the same as the first embodiment.

[0135] Light-emitting diode epitaxial wafers prepared in Examples 1 to 9 and Comparative Examples 1 and 2 were prepared into 10 mil × 24 mil chips using the same chip process conditions. 300 LED chips were extracted from each example and tested at a current of 120 mA. Compared with the LED prepared in Comparative Example 1, the improvement in luminous efficiency of each example was calculated. The specific test results are shown in Table 1.

[0136] Table 1 Performance test results of LEDs prepared in Examples 1 to 9 and Comparative Example 1

[0137]

[0138]

[0139] It can be seen from the above results that the light-emitting diode epitaxial wafer provided by the present invention can reduce electron overflow, improve hole injection efficiency, replenish hole concentration, and enhance the luminous efficiency of the light-emitting diode.

[0140] Throughout this specification, reference to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with an embodiment or example is included in at least one embodiment or example of the present application. In this specification, the illustrative use of the above terms does not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0141] The above is a preferred embodiment of the invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A light-emitting diode epitaxial wafer, characterized in that: The invention comprises a substrate, on which a buffer layer, an undoped GaN layer, an N-type GaN layer, an active layer, an electron blocking layer, and a P-type GaN layer are sequentially provided; The electron blocking layer includes a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer, and a BN layer which are stacked in sequence.

2. The light emitting diode epitaxial wafer according to claim 1, wherein: The BAlN / P-GaN superlattice layer includes BAlN layers and P-GaN layers stacked alternately, with the number of alternating periods being 1 to 10; The thickness of the BAlN / P-GaN superlattice layer is 1 nm to 50 nm.

3. The light emitting diode epitaxial wafer according to claim 2, wherein: The thickness ratio of the BAlN layer to the P-GaN layer is 1:(1-10); The B component of the BAlN layer is 0.01 to 0.1; The Mg doping concentration of the P-GaN layer is 1×10 17 atoms / cm 3 ~1×10 18 atoms / cm 3 .

4. The light emitting diode epitaxial wafer according to claim 1, wherein: The AlGaN / P-InGaN superlattice layer includes an AlGaN layer and a P-InGaN layer alternately stacked, and the number of alternating periods is 1 to 20; The thickness of the AlGaN / P-InGaN superlattice layer is 1 nm to 50 nm.

5. The light emitting diode epitaxial wafer according to claim 4, wherein: The thickness ratio of the AlGaN layer to the P-InGaN layer is (1-5):1; The Al composition of the AlGaN layer is 0.01 to 0.1; The Mg doping concentration of the P-InGaN layer is 1×10 18 atoms / cm 3 ~1×10 19 atoms / cm 3 .

6. The light emitting diode epitaxial wafer according to claim 1, wherein: The thickness of the BN layer is 0.1 nm to 10 nm.

7. A method for preparing a light emitting diode epitaxial wafer according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. providing a substrate; S2. Depositing a buffer layer, an undoped GaN layer, an N-type GaN layer, an active layer, an electron blocking layer, and a P-type GaN layer on the substrate in sequence; The electron blocking layer includes a BAlN / P-GaN superlattice layer, an AlGaN / P-InGaN superlattice layer, and a BN layer which are stacked in sequence.

8. The method for preparing a light emitting diode epitaxial wafer according to claim 7, wherein: The growth temperature of the BAlN / P-GaN superlattice layer is 900° C. to 1000° C., and the growth pressure is 50 torr to 500 torr; The growth temperature of the AlGaN / P-InGaN superlattice layer is 900° C. to 1000° C., and the growth pressure is 50 torr to 500 torr; The growth temperature of the BN layer is 900° C. to 1000° C., and the growth pressure is 50 torr to 500 torr.

9. An LED, characterized in that: The LED comprises the light emitting diode epitaxial wafer according to any one of claims 1 to 6.

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