Light emitting diode with improved luminous intensity and preparation method thereof

Abstract

The invention provides a light emitting diode with improved luminous intensity and a preparation method thereof, and belongs to the technical field of photoelectron manufacturing. The light-emitting diode comprises an n-type layer, an active layer, an electron blocking layer and a p-type layer which are stacked in sequence, the electron barrier layer comprises a first sub-layer, a second sub-layer, a third sub-layer, a fourth sub-layer, a fifth sub-layer, a sixth sub-layer, a seventh sub-layer and an eighth sub-layer which are stacked in sequence, the first sub-layer and the fifth sub-layer comprise AlN layers, the second sub-layer and the seventh sub-layer comprise AlInGaN layers, the third sub-layer comprises an AlGaN layer, and the eighth sub-layer comprises an AlGaN layer. And the fourth sub layer, the sixth sub layer and the eighth sub layer comprise p-type doped GaN layers. According to the embodiment of the invention, electron migration can be effectively blocked, hole injection is not influenced, and the luminous intensity of the light-emitting diode is ensured.

Description

Technical Field

[0001] The present disclosure relates to the field of optoelectronic manufacturing technology, and in particular to a light emitting diode with improved luminous intensity and a preparation method thereof. Background Art

[0002] Light Emitting Diode (LED) is a very influential new product in the optoelectronics industry. It has the characteristics of small size, long service life, rich colors and low energy consumption. It is widely used in lighting, display screens, signal lights, backlight sources, toys and other fields.

[0003] In the related art, a light-emitting diode generally includes a sapphire substrate, an n-type layer, an active layer, and a p-type layer stacked in sequence. Since the electron mobility is very high, the electrons formed in the n-type layer can easily pass through the active layer and enter the p-type layer, and non-radiatively recombine with the holes formed in the p-type layer, thereby reducing the light-emitting efficiency of the light-emitting diode. An electron blocking layer is usually set between the active layer and the p-type layer to prevent electrons from entering the p-type layer and non-radiatively recombine.

[0004] However, although the electron blocking layer can effectively block the migration of electrons, it will affect the injection of holes, thereby reducing the luminous intensity of the light-emitting diode. Summary of the invention

[0005] The embodiment of the present disclosure provides a light-emitting diode with improved luminous intensity and a method for manufacturing the same, which can effectively block electron migration while not affecting hole injection, thereby ensuring the luminous intensity of the light-emitting diode. The technical solution is as follows:

[0006] On the one hand, an embodiment of the present disclosure provides a light-emitting diode, which includes an n-type layer, an active layer, an electron blocking layer and a p-type layer stacked in sequence; the electron blocking layer includes a first sublayer, a second sublayer, a third sublayer, a fourth sublayer, a fifth sublayer, a sixth sublayer, a seventh sublayer and an eighth sublayer stacked in sequence, the first sublayer and the fifth sublayer include AlN layers, the second sublayer and the seventh sublayer include AlInGaN layers, the third sublayer includes an AlGaN layer, and the fourth sublayer, the sixth sublayer and the eighth sublayer include p-type doped GaN layers.

[0007] Optionally, the Al component content of the AlN layer in the first sublayer is greater than the Al component content of the AlN layer in the fifth sublayer.

[0008] Optionally, the Al component content of the AlN layer in the first sub-layer is 0.2 to 0.3, and the Al component content of the AlN layer in the fifth sub-layer is 0.1 to 0.15.

[0009] Optionally, the thickness of the first sublayer is greater than the thickness of the fifth sublayer.

[0010] Optionally, the Al component content of the AlInGaN layer in the second sublayer is greater than the Al component content of the AlInGaN layer in the seventh sublayer; and the In component content of the AlInGaN layer in the second sublayer is greater than the In component content of the AlInGaN layer in the seventh sublayer.

[0011] Optionally, the Al component content of the AlInGaN layer in the second sublayer is 0.15 to 0.25, and the In component content of the AlInGaN layer is 0.1 to 0.15; the Al component content of the AlInGaN layer in the seventh sublayer is 0.05 to 0.1, and the In component content of the AlInGaN layer is 0.05 to 0.1.

[0012] Optionally, the thickness of the second sublayer is smaller than the thickness of the seventh sublayer.

[0013] Optionally, the Al component content of the AlGaN layer in the third sublayer is 0.1 to 0.2.

[0014] Optionally, the fourth sublayer, the sixth sublayer and the eighth sublayer are GaN layers doped with Mg, and the Mg doping concentrations of the fourth sublayer, the sixth sublayer and the eighth sublayer increase sequentially.

[0015] On the other hand, an embodiment of the present disclosure provides a method for preparing a light-emitting diode, the method comprising: growing an n-type layer on a substrate; growing an active layer on the surface of the n-type layer; growing an electron blocking layer on the surface of the active layer, the electron blocking layer comprising a first sublayer, a second sublayer, a third sublayer, a fourth sublayer, a fifth sublayer, a sixth sublayer, a seventh sublayer and an eighth sublayer stacked in sequence, the first sublayer and the fifth sublayer comprising an AlN layer, the second sublayer and the seventh sublayer comprising an AlInGaN layer, the third sublayer comprising an AlGaN layer, the fourth sublayer, the sixth sublayer and the eighth sublayer comprising a p-type doped GaN layer; and growing a p-type layer on the surface of the electron blocking layer.

[0016] The beneficial effects brought by the technical solution provided by the embodiments of the present disclosure include at least:

[0017] The light-emitting diode provided by the embodiment of the present disclosure sets the electron blocking layer as eight sublayers stacked in sequence. The first sublayer uses an AlN layer with a higher energy level in order to first block a large number of electrons. Next, the second sublayer is an AlInGaN layer, which lowers the energy band compared to the first sublayer, so that the secondary blocking of electrons and the reduction of the blocking of holes can be taken into account. Subsequently, the third sublayer is an AlGaN layer, which raises the energy band again and plays the role of blocking electrons three times. Next, the fourth sublayer is a p-type doped GaN layer, which can improve the crystal quality and provide a hole channel. The fifth sublayer is an AlN layer that can block electrons four times. Then the sixth sublayer is a p-type doped GaN layer, which can form a hole channel to ensure the smooth migration of holes to the quantum well. The seventh sublayer is an AlInGaN layer, which is the last barrier to electrons and has a weak blocking effect on holes. Finally, the eighth sublayer is a p-type doped GaN layer, which has a low energy band and many hole channels, which can ensure that a large number of holes can migrate smoothly and form a hole flow. Since electrons are blocked by multiple channels and the energy band design takes into account the reduction of the blocking of holes, the non-radiative recombination is greatly reduced on the one hand, and the radiative recombination of holes and electrons is enhanced on the other hand. Under high current conditions, since the mobility of electrons is stronger under the action of high current, the stronger the blocking effect on electrons, the greater the effective luminous intensity of the light-emitting diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 is a structural schematic diagram of a light emitting diode provided by an embodiment of the present disclosure;

[0020] Figure 2 It is a flow chart of a method for preparing a light emitting diode provided in an embodiment of the present disclosure.

[0021] The descriptions of the marks in the figure are as follows:

[0022] 10. Substrate;

[0023] 20. n-type layer;

[0024] 30. Active layer; 31. Quantum well layer; 32. Quantum barrier layer

[0025] 40, electron blocking layer; 41, first sublayer; 42, second sublayer; 43, third sublayer; 44, fourth sublayer; 45, fifth sublayer; 46, sixth sublayer; 47, seventh sublayer; 48, eighth sublayer;

[0026] 50. p-type layer;

[0027] 60. Buffer layer;

[0028] 70. Fill the layer. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0030] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons with ordinary skills in the field to which the present disclosure belongs. The words "first", "second", "third" and similar words used in the patent application specification and claims of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not indicate a quantity limitation, but indicate the existence of at least one. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right", "top", "bottom" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0031] Figure 1 Schematic diagram of the structure of a light emitting diode provided by an embodiment of the present disclosure. Figure 1 As shown, the light emitting diode includes an n-type layer 20, an active layer 30, an electron blocking layer 40 and a p-type layer 50 which are stacked in sequence.

[0032] like Figure 1 As shown, the electron blocking layer 40 includes a first sublayer 41, a second sublayer 42, a third sublayer 43, a fourth sublayer 44, a fifth sublayer 45, a sixth sublayer 46, a seventh sublayer 47 and an eighth sublayer 48 which are stacked in sequence.

[0033] The first sublayer 41 and the fifth sublayer 45 include AlN layers, the second sublayer 42 and the seventh sublayer 47 include AlInGaN layers, the third sublayer 43 includes AlGaN layers, and the fourth sublayer 44, the sixth sublayer 46 and the eighth sublayer 48 include p-type doped GaN layers.

[0034] The light-emitting diode provided in the embodiment of the present disclosure sets the electron blocking layer 40 as eight sublayers stacked in sequence. The first sublayer 41 uses an AlN layer with a higher energy level in order to first block a large number of electrons. Next, the second sublayer 42 is an AlInGaN layer, which reduces the energy band compared to the first sublayer 41, so that the secondary blocking of electrons and the reduction of the blocking of holes can be taken into account. Subsequently, the third sublayer 43 is an AlGaN layer, which raises the energy band again and plays a role in blocking electrons three times. Next, the fourth sublayer 44 is a p-type doped GaN layer, which can improve the crystal quality and provide a hole channel. The fifth sublayer 45 is an AlN layer that can block electrons four times. Then the sixth sublayer 46 is a p-type doped GaN layer, which can form a hole channel to ensure the smooth migration of holes to the quantum well. The seventh sublayer 47 is an AlInGaN layer, which is the last barrier to electrons and has a weak blocking effect on holes. Finally, the eighth sublayer 48 is a p-type doped GaN layer, which has a low energy band and many hole channels, and can ensure that a large number of holes can migrate smoothly to form a hole flow. Since the electrons are blocked by multiple channels, and the energy band design takes into account the reduction of the blocking of holes, on the one hand, the non-radiative recombination is greatly reduced, and on the other hand, the radiative recombination of holes and electrons is also enhanced. Under high current conditions, since the mobility of electrons is stronger under the action of high current, the stronger the blocking effect on electrons, the greater the effective luminous intensity of the light-emitting diode.

[0035] Optionally, the Al component content of the AlN layer in the first sub-layer 41 is greater than the Al component content of the AlN layer in the fifth sub-layer 45 .

[0036] In the above implementation, the first sublayer 41 and the second sublayer 42 are both AlN layers. As the AlN layer has a higher Al content, the AlN layer has a higher resistance. The high-resistance AlN layer acts as a "dam" and stores electrons, preventing them from quickly entering the p-type layer 50.

[0037] By controlling the Al component content in the first sublayer 41 close to the active layer 30 to be greater than the Al component content in the fifth sublayer 45, the first sublayer 41 is used to form a "water dam" with the best interception effect, so as to store electrons to the maximum extent and prevent the electrons from flowing to the p-type layer 50. At the same time, the fifth sublayer 45 with a relatively low Al component content is also provided to intercept and store the electrons again, so as to prevent the fifth sublayer 45 close to the p-type layer 50 from affecting the transmission of holes.

[0038] Optionally, the Al component content of the AlN layer in the first sub-layer 41 is 0.2 to 0.3, and the Al component content of the AlN layer in the fifth sub-layer 45 is 0.1 to 0.15.

[0039] Exemplarily, the Al component content of the AlN layer in the first sub-layer 41 is 0.25, and the Al component content of the AlN layer in the fifth sub-layer 45 is 0.1.

[0040] Optionally, the thickness of the first sublayer 41 is greater than the thickness of the fifth sublayer 45 .

[0041] The AlN layer is used as the fifth sublayer 45. Although the AlN layer has a high energy band, the thickness of the fifth sublayer 45 is reduced to a certain extent compared with the thickness of the first sublayer 41, and the Al component content of the fifth sublayer 45 is also less. Therefore, in addition to blocking electrons, it can also avoid affecting the injection of holes.

[0042] Exemplarily, the thickness of the first sublayer 41 is 20 nm to 40 nm. For example, the thickness of the first sublayer 41 is 30 nm.

[0043] Exemplarily, the thickness of the fifth sublayer 45 is 10 nm to 20 nm. For example, the thickness of the fifth sublayer 45 is 15 nm.

[0044] Optionally, the Al component content of the AlInGaN layer in the second sub-layer 42 is greater than the Al component content of the AlInGaN layer in the seventh sub-layer 47 .

[0045] The In component content of the AlInGaN layer in the second sub-layer 42 is greater than the In component content of the AlInGaN layer in the seventh sub-layer 47 .

[0046] In the disclosed embodiment, the second sublayer 42 is an AlInGaN layer with high Al content and high In content, which can reduce the energy band compared with the AlN layer in the first sublayer 41, taking into account the secondary blocking of electrons and reducing the blocking of holes. At the same time, the seventh sublayer 47 is set to be an AlInGaN layer with low Al content and low In content, which is the last barrier for electrons and has a very weak blocking effect on holes.

[0047] Optionally, the Al component content of the AlInGaN layer in the second sub-layer 42 is 0.15 to 0.25, and the In component content of the AlInGaN layer is 0.1 to 0.15.

[0048] Exemplarily, the Al component content of the AlInGaN layer in the second sub-layer 42 is 0.2, and the In component content of the AlInGaN layer is 0.1.

[0049] Optionally, the Al component content of the AlInGaN layer in the seventh sub-layer 47 is 0.05 to 0.1, and the In component content of the AlInGaN layer is 0.05 to 0.1.

[0050] Exemplarily, the Al component content of the AlInGaN layer in the seventh sub-layer 47 is 0.1, and the In component content of the AlInGaN layer is 0.06.

[0051] Optionally, the thickness of the second sublayer 42 is less than that of the seventh sublayer 47. The thickness of the second sublayer 42 is set smaller to prevent the AlInGaN layer with high Al component content and high In component content from causing a large barrier to holes and interfering with the hole injection efficiency.

[0052] Exemplarily, the thickness of the second sub-layer 42 is 5 nm to 10 nm. For example, the thickness of the second sub-layer 42 is 8 nm.

[0053] Exemplarily, the thickness of the seventh sublayer 47 is 10 nm to 20 nm. For example, the thickness of the seventh sublayer 47 is 15 nm.

[0054] Optionally, the Al component content of the AlGaN layer in the third sub-layer 43 is 0.1 to 0.2.

[0055] Since the Al component content affects the bandgap width of AlGaN, and the higher the Al component content, the larger the bandgap width of AlGaN, and the larger the barrier height of AlGaN. Therefore, the embodiment of the present disclosure limits the Al component content of the AlGaN layer in the three sub-layers to the above-mentioned lower range, so as to avoid blocking the injection of holes, and at the same time allow the holes to expand laterally, so that the holes are uniformly injected into the active layer 30, thereby improving the recombination efficiency of the light-emitting diode.

[0056] Exemplarily, the Al component content of the AlGaN layer in the third sub-layer 43 is 0.15.

[0057] Optionally, the fourth sublayer 44 , the sixth sublayer 46 , and the eighth sublayer 48 are GaN layers doped with Mg, and the Mg doping concentrations of the fourth sublayer 44 , the sixth sublayer 46 , and the eighth sublayer 48 increase sequentially.

[0058] For example, the Mg doping concentration of the fourth sublayer 44 is 1×10 18 Up to 5×10 18 / cm -3 For example, the Mg doping concentration of the fourth sublayer 44 is 2×10 18 / cm -3 .

[0059] For example, the Mg doping concentration of the sixth sublayer 46 is 5×10 18 Up to 1×10 19 / cm -3 For example, the Mg doping concentration of the sixth sublayer 46 is 8×10 18 / cm -3 .

[0060] For example, the Mg doping concentration of the eighth sublayer 48 is 1×10 19 Up to 5×10 19 / cm -3 For example, the Mg doping concentration of the eighth sublayer 48 is 2×10 19 / cm -3 .

[0061] First, the Mg-doped GaN layer is grown as the fourth sublayer 44, which mainly serves to improve the crystal quality and provide a hole channel. Then, the sixth sublayer 46 with a relatively high Mg doping is grown to form a hole channel and ensure the smooth migration of holes to the quantum well. Finally, the eighth sublayer 48 with a high Mg doping is grown, which has a low energy band and many hole channels, in order to ensure that a large number of holes can migrate smoothly and form a hole flow.

[0062] Exemplarily, the thickness of the fourth sublayer 44 is 5 nm to 10 nm. For example, the thickness of the fourth sublayer 44 is 6 nm.

[0063] Exemplarily, the thickness of the sixth sublayer 46 is 10 nm to 20 nm. For example, the thickness of the sixth sublayer 46 is 15 nm.

[0064] Exemplarily, the eighth sublayer 48 has a thickness of 5 nm to 10 nm. For example, the eighth sublayer 48 has a thickness of 6 nm.

[0065] Alternatively, if Figure 1 As shown, the light emitting diode further comprises a substrate 10, a buffer layer 60 and a fill layer 70. The substrate 10, the buffer layer 60, the fill layer 70, the n-type layer 20, the active layer 30, the electron blocking layer 40 and the p-type layer 50 are stacked in sequence.

[0066] Alternatively, the buffer layer 60 may include a low-temperature GaN layer and a high-temperature GaN layer sequentially stacked on the substrate 10 .

[0067] Exemplarily, the thickness of the buffer layer 60 is 10 nm to 20 nm. For example, the thickness of the buffer layer 60 is 15 nm.

[0068] Optionally, the fill layer 70 may be a GaN layer.

[0069] Exemplarily, the thickness of the leveling layer 70 is 0.35 μm to 0.5 μm. For example, the thickness of the leveling layer 70 is 0.4 μm.

[0070] Alternatively, the n-type layer 20 may be an n-type GaN layer. The thickness of the n-type layer 20 is 1.5 μm to 3.5 μm.

[0071] The dopant of the n-type layer 20 is silane.

[0072] Alternatively, the p-type layer 50 may include a low-temperature p-type GaN layer, a p-type AlGaN layer, a high-temperature p-type GaN layer and a p-type ohmic contact layer sequentially stacked on the active layer 30. Both the low-temperature p-type GaN layer and the high-temperature p-type GaN layer are doped with Mg.

[0073] In the embodiment of the present disclosure, the thickness of the quantum well layer 31 in the active layer 30 is 2 nm to 5 nm.

[0074] By controlling the thickness of the quantum well layer 31 within the above range, it is possible to avoid the quantum well layer 31 being too thin to achieve the purpose of electron-hole recombination; it is also possible to avoid the quantum well layer 31 being too thick to increase the manufacturing cost.

[0075] Exemplarily, the thickness of the quantum well layer 31 may be 3 nm.

[0076] Optionally, the quantum barrier layer 32 may be an n-type GaN quantum barrier layer 32 with a thickness of 5 nm to 15 nm.

[0077] By controlling the thickness of the n-type GaN quantum barrier layer 32 within the above range, it is possible to avoid setting the thickness of the n-type GaN quantum barrier layer 32 too thin to achieve the purpose of electron-hole recombination; it is also possible to avoid setting the thickness of the n-type GaN quantum barrier layer 32 too thick to increase the manufacturing cost.

[0078] Exemplarily, the thickness of the n-type GaN quantum barrier layer 32 is 10 nm.

[0079] Optionally, the active layer 30 includes 8 to 12 quantum well layers 31 and 8 to 12 quantum barrier layers 32 .

[0080] By controlling the number of quantum well layers 31 and quantum barrier layers 32 within the above range, it is possible to avoid setting the number of quantum well layers 31 and quantum barrier layers 32 too small, which would result in the thickness of the active layer 30 being too small and failing to meet the purpose of electron-hole recombination; it is also possible to avoid setting the thickness of the active layer 30 too thick and increasing the production cost.

[0081] By way of example, the number of layers of the quantum well layer 31 may be 10, and the number of layers of the quantum barrier layer 32 may be 10.

[0082] It should be noted that Figure 1 Only a partial structure of the active layer 30 is shown, and it is not intended to limit the number of cycles of the alternate stacking of the quantum well layer 31 and the quantum barrier layer 32 .

[0083] Figure 2 FIG. 1 is a flow chart of a method for preparing a light emitting diode provided by an embodiment of the present disclosure. Figure 2 As shown, the preparation method comprises:

[0084] Step S11: growing an n-type layer on a substrate.

[0085] Step S12: growing an active layer on the surface of the n-type layer.

[0086] Step S13: growing an electron blocking layer on the surface of the active layer.

[0087] The electron blocking layer includes a first sublayer, a second sublayer, a third sublayer, a fourth sublayer, a fifth sublayer, a sixth sublayer, a seventh sublayer and an eighth sublayer stacked in sequence, the first sublayer and the fifth sublayer include an AlN layer, the second sublayer and the seventh sublayer include an AlInGaN layer, the third sublayer includes an AlGaN layer, and the fourth sublayer, the sixth sublayer and the eighth sublayer include a p-type doped GaN layer;

[0088] Step S14: growing a p-type layer on the surface of the electron blocking layer.

[0089] When preparing a light-emitting diode in the embodiment of the present disclosure, the AlN layer with a higher energy level is first grown as the first sublayer in order to block a large number of electrons first. Then, the AlInGaN layer is grown as the second sublayer, which lowers the energy band compared to the first sublayer, so that the secondary blocking of electrons and the reduction of the blocking of holes can be taken into account. Subsequently, the AlGaN layer is grown as the third sublayer to raise the energy band again, which plays the role of blocking electrons three times. Next, the p-type doped GaN layer is grown as the fourth sublayer, which can improve the crystal quality and provide a hole channel. Next, the AlN layer is grown as the fifth sublayer, which can play the role of blocking electrons four times. Then the p-type doped GaN layer is grown as the sixth sublayer, which can form a hole channel and ensure the smooth migration of holes to the quantum well. Next, the AlInGaN layer is grown as the seventh sublayer, which is the last barrier to electrons and has a weak blocking effect on holes. Finally, the p-type doped GaN layer is grown as the eighth sublayer, which has a low energy band and many hole channels, and can ensure that a large number of holes can migrate smoothly to form a hole flow. Since electrons are blocked by multiple channels and the energy band design takes into account the reduction of the blocking of holes, the non-radiative recombination is greatly reduced on the one hand, and the radiative recombination of holes and electrons is enhanced on the other hand. Under high current conditions, since the mobility of electrons is stronger under the action of high current, the stronger the blocking effect on electrons, the greater the effective luminous intensity of the light-emitting diode.

[0090] Optionally, before step S11, the method further includes sequentially growing a buffer layer and a fill layer on the substrate.

[0091] Exemplarily, the substrate is a sapphire substrate, a silicon substrate or a silicon carbide substrate. The substrate can be a flat substrate or a patterned substrate.

[0092] As an example, in the embodiment of the present disclosure, the substrate is a sapphire substrate. The sapphire substrate is a commonly used substrate with mature technology and low cost. Specifically, it can be a patterned sapphire substrate or a sapphire flat sheet substrate.

[0093] Exemplarily, the buffer layer may be at least one of a GaN layer, an AlN layer, and an AlGaN layer.

[0094] For example, the buffer layer includes a low-temperature GaN layer and a high-temperature GaN layer which are stacked.

[0095] Exemplarily, the fill layer may be a GaN layer.

[0096] In the disclosed embodiment, the buffer layer, the fill layer, the n-type layer, the active layer, the electron blocking layer and the p-type layer are all grown in a reaction chamber, which is a reaction chamber of a MOCVD (Metal Organic Chemical Vapor Deposition) device.

[0097] When growing each film layer, the growth substrate is placed in a graphite disk in a MOCVD reaction chamber, and each film layer is formed on the substrate in the graphite disk by introducing MO source and reaction gas into the reaction chamber and controlling the rotation of the graphite disk.

[0098] In the embodiment of the present disclosure, growing the buffer layer may include: sequentially growing a low-temperature GaN layer and a high-temperature GaN layer on a substrate.

[0099] Illustratively, when growing a low-temperature GaN layer, the temperature in the reaction chamber is controlled to be 530° C. to 560° C., the growth pressure is 200 torr to 500 torr, and a low-temperature GaN layer with a thickness of 15 nm to 30 nm is grown on the substrate.

[0100] Exemplarily, when growing a high-temperature GaN layer on a low-temperature GaN layer, the temperature in the reaction chamber is controlled to be 1000°C to 1100°C, the growth pressure is 200 torr to 600 torr, and a high-temperature GaN layer with a thickness of 2 μm to 3.5 μm is grown on the low-temperature GaN layer.

[0101] Growing the leveling layer may include: sequentially introducing a Si source with a flow rate of 5 sccm to 10 sccm into the reaction chamber to grow a GaN layer.

[0102] Exemplarily, the quality of the GaN leveling layer obtained by introducing Si source with a flow rate of 5 sccm to 10 sccm into the reaction chamber for 3 min to 5 min is good.

[0103] For example, the growth temperature of the GaN filling layer may be 1090° C. to 1120° C., and the growth pressure of the GaN filling layer may be 150 torr to 300 torr.

[0104] Step S11 may include: growing an n-type layer on the leveling layer.

[0105] Optionally, the n-type layer may be an n-type GaN layer. The thickness of the n-type layer is 1.5 μm to 3.5 μm. The dopant of the n-type layer is silane.

[0106] Specifically, after the growth of the undoped GaN layer is completed, a layer of n-type GaN layer with a stable Si doping concentration is grown with a thickness of 1.5 μm to 3.5 μm, a growth temperature of 950° C. to 1150° C., a growth pressure of 300 Torr to 500 Torr, and a V / III ratio of 400 to 3000.

[0107] Growing the active layer in step S12 may include: after the growth of the n-type layer is completed, growing alternately stacked quantum well layers and quantum barrier layers.

[0108] Wherein, the quantum well layer is an InGaN layer.

[0109] When growing the quantum well layer, ammonia, ethylgallium and trimethylindium are introduced into the reaction chamber for 30 to 60 seconds, and the growth temperature in the reaction chamber is controlled to be 700°C to 850°C, the growth pressure is 100 Torr to 500 Torr, the V / III ratio is 2000 to 20000, and the thickness is 2nm to 5nm.

[0110] Exemplarily, the thickness of the quantum well layer may be 3 nm.

[0111] In the embodiment of the present disclosure, the quantum barrier layer may be an n-type GaN quantum barrier layer.

[0112] When growing the quantum barrier layer, the growth temperature in the reaction chamber is controlled to be 850° C. to 950° C., the growth pressure is controlled to be 100 Torr to 500 Torr, the V / III ratio is controlled to be 2000 to 20000, and the thickness is controlled to be 5 nm to 15 nm.

[0113] Exemplarily, the thickness of the n-type GaN quantum barrier layer is 10 nm.

[0114] Optionally, the number of quantum well layers and the number of quantum barrier layers are both 8 to 12. Exemplarily, the number of quantum well layers and the number of quantum barrier layers are both 10.

[0115] Step S13 may include: sequentially growing a first sublayer, a second sublayer, a third sublayer, a fourth sublayer, a fifth sublayer, a sixth sublayer, a seventh sublayer and an eighth sublayer on the surface of the active layer.

[0116] Optionally, the Al component content of the AlN layer in the first sublayer is 0.2 to 0.3, and the Al component content of the AlN layer in the fifth sublayer is 0.1 to 0.15.

[0117] Exemplarily, the Al component content of the AlN layer in the first sub-layer is 0.25, and the Al component content of the AlN layer in the fifth sub-layer is 0.1.

[0118] Exemplarily, the thickness of the first sublayer is 20 nm to 40 nm. For example, the thickness of the first sublayer is 30 nm.

[0119] Exemplarily, the thickness of the fifth sublayer is 10 nm to 20 nm. For example, the thickness of the fifth sublayer is 15 nm.

[0120] Optionally, in the second sublayer, the Al component content of the AlInGaN layer is 0.15 to 0.25, and the In component content of the AlInGaN layer is 0.1 to 0.15.

[0121] Exemplarily, the Al component content of the AlInGaN layer in the second sub-layer is 0.2, and the In component content of the AlInGaN layer is 0.1.

[0122] Optionally, in the seventh sublayer, the Al component content of the AlInGaN layer is 0.05 to 0.1, and the In component content of the AlInGaN layer is 0.05 to 0.1.

[0123] Exemplarily, the Al component content of the AlInGaN layer in the seventh sub-layer is 0.1, and the In component content of the AlInGaN layer is 0.06.

[0124] Exemplarily, the thickness of the second sub-layer is 5 nm to 10 nm. For example, the thickness of the second sub-layer is 8 nm.

[0125] Exemplarily, the thickness of the seventh sublayer is 10 nm to 20 nm. For example, the thickness of the seventh sublayer is 15 nm.

[0126] Optionally, the Al component content of the AlGaN layer in the third sublayer is 0.1 to 0.2.

[0127] Exemplarily, the Al component content of the AlGaN layer in the third sub-layer is 0.15.

[0128] For example, the Mg doping concentration of the fourth sublayer is 1×10 18 Up to 5×10 18 / cm -3 For example, the Mg doping concentration of the fourth sublayer is 2×10 18 / cm -3 .

[0129] For example, the Mg doping concentration of the sixth sublayer is 5×10 18 Up to 1×10 19 / cm-3 For example, the Mg doping concentration of the sixth sublayer is 8×10 18 / cm -3 .

[0130] For example, the Mg doping concentration of the eighth sublayer is 1×10 19 Up to 5×10 19 / cm -3 For example, the Mg doping concentration of the eighth sublayer is 2×10 19 / cm -3 .

[0131] Exemplarily, the thickness of the fourth sublayer is 5 nm to 10 nm. For example, the thickness of the fourth sublayer is 6 nm.

[0132] Exemplarily, the thickness of the sixth sublayer is 10 nm to 20 nm. For example, the thickness of the sixth sublayer is 15 nm.

[0133] Exemplarily, the thickness of the eighth sublayer is 5 nm to 10 nm. For example, the thickness of the eighth sublayer is 6 nm.

[0134] Growing the p-type layer in step S14 may include: sequentially growing a low-temperature p-type GaN layer, a p-type AlGaN layer, a high-temperature p-type GaN layer, and a p-type ohmic contact layer on the electron blocking layer.

[0135] Wherein, both the low-temperature p-type GaN layer and the high-temperature p-type GaN layer are doped with Mg.

[0136] The thickness of the low-temperature p-type GaN layer may be 30 nm to 120 nm. For example, the thickness of the low-temperature p-type GaN layer may be 100 nm.

[0137] The thickness of the high temperature p-type GaN layer may be 50 nm to 150 nm, for example, the thickness of the low temperature p-type GaN layer may be 100 nm.

[0138] In the embodiment of the present disclosure, the p-type AlGaN layer can block electrons from entering the p-type layer. Both the p-type AlGaN layer and the p-type ohmic contact layer are doped with Mg.

[0139] Optionally, the thickness of the p-type AlGaN layer may be 50 nm to 150 nm. As an example, in the embodiment of the present disclosure, the thickness of the p-type AlGaN layer is 80 nm.

[0140] Optionally, the thickness of the p-type ohmic contact layer may be 3 nm to 10 nm. As an example, in the embodiment of the present disclosure, the thickness of the p-type ohmic contact layer is 8 nm.

[0141] Specifically, when growing the p-type layer, a low-temperature p-type GaN layer with a thickness of 30nm to 120nm is first grown, the growth temperature is 700℃ to 800℃, the growth time is 3min to 15min, the pressure is 100Torr to 600Torr, and the V / III ratio is 1000 to 4000.

[0142] After the growth of the low-temperature p-type GaN layer is completed, a p-type AlGaN layer with a thickness of 50nm to 150nm is grown, the growth temperature is 900°C to 1000°C, the growth time is 4min to 15min, the growth pressure is 50Torr to 300Torr, and the V / III ratio is 1000 to 10000.

[0143] After the growth of the p-type AlGaN layer is completed, a high-temperature p-type GaN layer with a thickness of 50nm to 150nm is grown, the growth temperature is between 900℃ and 1050℃, the growth time is 10min to 20min, the growth pressure is 100Torr to 500Torr, and the V / III ratio is 500 to 4000.

[0144] After the growth of the high-temperature p-type GaN layer is completed, a p-type ohmic contact layer with a thickness of 3nm to 10nm is grown, the growth temperature is 700℃ to 850℃, the growth time is 0.5min to 5min, the growth pressure is 100Torr to 500Torr, and the V / III ratio is 10000 to 20000.

[0145] After step S14, the method further includes: annealing the epitaxial wafer.

[0146] After the epitaxial growth is completed, the temperature of the reaction chamber is lowered to 600℃ to 900℃, and annealing treatment is carried out in PN2 atmosphere for 10min to 30min, and then gradually lowered to room temperature. Subsequently, a single 22×35mil chip is made through subsequent processing such as cleaning, deposition, photolithography and etching.

[0147] In specific implementation, the embodiments of the present disclosure can use high-purity H2 and / or N2 as carrier gas, TEGa or TMGa as Ga source, TMIn as In source, SiH4 as n-type dopant, TMAl as aluminum source, ammonia as N source, and Cp2Mg as p-type dopant.

[0148] The above description is only an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A light emitting diode, characterized in that: The light-emitting diode comprises an n-type layer (20), an active layer (30), an electron blocking layer (40) and a p-type layer (50) which are stacked in sequence; The electron blocking layer (40) comprises a first sublayer (41), a second sublayer (42), a third sublayer (43), a fourth sublayer (44), a fifth sublayer (45), a sixth sublayer (46), a seventh sublayer (47) and an eighth sublayer (48) which are stacked in sequence, wherein the first sublayer (41) and the fifth sublayer (45) comprise AlN layers, the second sublayer (42) and the seventh sublayer (47) comprise AlInGaN layers, the third sublayer (43) comprises an AlGaN layer, and the fourth sublayer (44), the sixth sublayer (46) and the eighth sublayer (48) comprise p-type doped GaN layers.

2. The light emitting diode according to claim 1, characterized in that: The Al component content of the AlN layer in the first sub-layer (41) is greater than the Al component content of the AlN layer in the fifth sub-layer (45).

3. The light emitting diode according to claim 2, characterized in that: The Al component content of the AlN layer in the first sub-layer (41) is 0.2 to 0.3, and the Al component content of the AlN layer in the fifth sub-layer (45) is 0.1 to 0.

15.

4. The light emitting diode according to claim 2, characterized in that: The thickness of the first sub-layer (41) is greater than the thickness of the fifth sub-layer (45).

5. The light emitting diode according to any one of claims 1 to 4, characterized in that: The Al component content of the AlInGaN layer in the second sub-layer (42) is greater than the Al component content of the AlInGaN layer in the seventh sub-layer (47); The In component content of the AlInGaN layer in the second sub-layer (42) is greater than the In component content of the AlInGaN layer in the seventh sub-layer (47).

6. The light emitting diode according to claim 5, characterized in that: The Al component content of the AlInGaN layer in the second sublayer (42) is 0.15 to 0.25, and the In component content of the AlInGaN layer is 0.1 to 0.15; The Al component content of the AlInGaN layer in the seventh sub-layer (47) is 0.05 to 0.1, and the In component content of the AlInGaN layer is 0.05 to 0.

1.

7. The light emitting diode according to claim 5, characterized in that: The thickness of the second sub-layer (42) is smaller than the thickness of the seventh sub-layer (47).

8. The light emitting diode according to any one of claims 1 to 4, characterized in that: The Al component content of the AlGaN layer in the third sublayer (43) is 0.1 to 0.

2.

9. The light emitting diode according to any one of claims 1 to 4, characterized in that: The fourth sublayer (44), the sixth sublayer (46) and the eighth sublayer (48) are GaN layers doped with Mg, and the Mg doping concentrations of the fourth sublayer (44), the sixth sublayer (46) and the eighth sublayer (48) increase sequentially.

10. A method for preparing a light emitting diode, characterized in that: The preparation method comprises: growing an n-type layer on a substrate; growing an active layer on a surface of the n-type layer; An electron blocking layer is grown on the surface of the active layer, the electron blocking layer comprising a first sublayer, a second sublayer, a third sublayer, a fourth sublayer, a fifth sublayer, a sixth sublayer, a seventh sublayer and an eighth sublayer stacked in sequence, the first sublayer and the fifth sublayer comprising an AlN layer, the second sublayer and the seventh sublayer comprising an AlInGaN layer, the third sublayer comprising an AlGaN layer, and the fourth sublayer, the sixth sublayer and the eighth sublayer comprising a p-type doped GaN layer; A p-type layer is grown on the surface of the electron blocking layer.

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