Light emitting diode and light emitting device

Abstract

The invention discloses a light emitting diode and a light emitting device, in the light emitting diode, an electron blocking layer is formed between a second semiconductor layer and an active layer, an insertion layer is formed between the electron blocking layer and the active layer, the insertion layer comprises a first layer structure, a second layer structure and a third layer structure which are stacked in sequence, the first layer structure and the third layer structure are AlN layers, and the second layer structure is an AlGaN layer or a GaN layer. According to the insertion layer, the AlGaN layer or the GaN layer is formed between the two AlN layers, meanwhile, the Al content in the AlGaN layer is controlled to be lower than 10%, due to the fact that the AlGaN layer or the GaN layer with the low Al content is narrow in energy gap, and AlN has a very wide energy gap, obvious energy gap difference is formed between the material layers of the insertion layer, the energy gap difference can form a tunneling effect, the hole injection energy level is reduced, and the hole injection efficiency is improved. Therefore, the electron hole recombination efficiency of the active layer is improved, and the light emitting effect of the light emitting diode is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor devices, and in particular to a light emitting diode and a light emitting device. Background Art

[0002] A light-emitting diode (LED) is a semiconductor diode structure that converts electrical energy into light energy. It has the advantages of high contrast, high brightness, low energy consumption, short response time, high reliability and long life, making LED widely used in many fields, such as high-definition display, lighting, visible light communication and biomedicine.

[0003] LEDs made of III-V semiconductor materials containing gallium nitride can control the emission of various colors through the material composition ratio, and are the focus of current industry research. LED epitaxial wafers usually include a substrate, an N-type semiconductor layer, an active layer, and a P-type semiconductor layer. The P-type semiconductor layer is used to provide holes for compound luminescence, the N-type semiconductor layer is used to provide electrons for compound luminescence, and the active layer is used for radiation compound luminescence of electrons and holes.

[0004] Research has found that LEDs in the prior art have at least the following problems:

[0005] First, the number of electrons provided by the N-type semiconductor is far greater than the number of holes provided by the P-type semiconductor layer, resulting in the number of electrons injected into the active layer being far greater than the number of holes; secondly, the mobility of holes is much smaller than the mobility of electrons, so the diffusion capacity of holes is poor, which in turn affects the injection efficiency of holes into the active layer. The above easily causes the excess electrons in the active layer to jump to the P-type semiconductor layer and non-radiatively recombine with holes. In order to reduce such non-radiative recombination, an electron blocking layer (EBL) is usually added between the P-type semiconductor layer and the active layer. However, although the electron blocking layer can block the transition of electrons to the P-type semiconductor layer, it will also block the migration of holes, resulting in fewer holes injected into the active layer, thereby reducing the composite luminescence efficiency of electrons and holes in the active layer. Summary of the invention

[0006] In view of the defects and deficiencies of light-emitting diodes in the prior art, the purpose of the present invention is to provide a light-emitting diode and a light-emitting device. The present invention improves the structure of semiconductor epitaxial materials and selects materials, forms a tunneling effect through the energy gap difference between different semiconductor materials, reduces the hole injection energy level and improves its injection efficiency, improves the electron-hole recombination efficiency of the active layer, and improves the light-emitting effect of the light-emitting diode.

[0007] To achieve the above-mentioned purpose and other related purposes, the present invention provides a light-emitting diode on one hand, which at least includes a semiconductor stack, wherein the semiconductor stack includes a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence, an electron blocking layer is formed between the second semiconductor layer and the active layer, an insertion layer is formed between the electron blocking layer and the active layer, and along the direction from the active layer to the electron blocking layer, the insertion layer includes a first layer structure, a second layer structure and a third layer structure stacked in sequence, wherein the first layer structure and the third layer structure are AlN layers, and the second layer structure is an AlGaN layer.

[0008] A second aspect of the present invention provides a light-emitting device, which includes a substrate and a plurality of light-emitting units located on the substrate, wherein the light-emitting units include the light-emitting diodes described in the present application.

[0009] As described above, the light-emitting diode and the light-emitting device provided by the present invention have at least the following beneficial technical effects: in the light-emitting diode of the present invention, an insertion layer is formed between the electron blocking layer and the active layer, and along the direction from the active layer to the electron blocking layer, the insertion layer includes a first layer structure, a second layer structure and a third layer structure stacked in sequence, the first layer structure and the third layer structure are AlN layers, and the second layer structure is Al x1 Ga (1-x1) N layer, wherein x1≥0. The above-mentioned insertion layer is formed by forming an AlGaN layer or a GaN layer between two AlN layers. Since the energy gap of GaN is about 3.4eV, its energy gap is relatively narrow, and in the present application, the Al content in the second layer structure AlGaN layer can be further controlled to be lower than 10%, so that its energy gap is close to the energy gap of GaN, and AlN has a very wide energy gap, and its energy gap size is about 6.0eV, thereby forming a significant energy gap difference between the material layers of the above-mentioned insertion layer, and the energy gap difference can form a tunneling effect, reduce the hole injection energy level, and improve the hole injection efficiency, thereby improving the electron-hole recombination efficiency of the active layer, which is helpful to improve the light-emitting effect of the light-emitting diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Shown is a schematic diagram of the structure of a light emitting diode provided in Example 1 of the present application.

[0011] Figure 2 Display as Figure 1 Schematic diagram of the structure of the insertion layer and electron blocking layer in the light-emitting diode.

[0012] Figure 3 Display as Figure 1 The wavelength vs. optical power comparison diagram of the light emitting diode shown is compared with the light emitting diode in the prior art.

[0013] Figure 4A schematic diagram showing the structure of the light-emitting device provided in the second embodiment of the present application is shown.

[0014] Reference numerals

[0015] 100, substrate; 200, semiconductor stack; 201, first semiconductor layer; 2011, buffer layer; 2012, N-type electron injection layer; 2013, stress release layer; 202, active layer; 203, second semiconductor layer; 2031, P-type hole injection layer; 2032, P-type ohmic contact layer; 204, electron blocking layer; 205, insertion layer; 2051, first layer structure; 2052, second layer structure; 2053, third layer structure; 301, first electrode; 302, second electrode; 400, insulating protection layer.

[0016] 500, light-emitting device; 501, circuit substrate, 502, light-emitting unit; 503, circuit layer; 504, housing; 505, solder pad. DETAILED DESCRIPTION

[0017] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0018] It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner. Although the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation, the form, quantity, positional relationship and proportion of each component in actual implementation can be changed at will under the premise of realizing the technical solution of this party, and the component layout form may also be more complicated.

[0019] In order to solve the problem in the prior art that the number of holes injected into the active layer is small and the composite luminescence efficiency of electrons and holes in the active layer is low, the present application provides a light-emitting diode on one hand, which at least includes: a semiconductor stack, the semiconductor stack includes a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence, wherein an electron blocking layer is formed between the second semiconductor layer and the active layer, an insertion layer is formed between the electron blocking layer and the active layer, and along the direction from the active layer to the electron blocking layer, the insertion layer includes a first layer structure, a second layer structure and a third layer structure stacked in sequence, the first layer structure and the third layer structure are AlN layers, and the second layer structure is Al x1 Ga (1-x1) N layers, where x1≥0.

[0020] Since the energy gap of AlGaN or GaN is narrow, and AlN has a very wide energy gap of about 6.0 eV, an energy gap difference is formed between the material layers of the above-mentioned insertion layer. The energy gap difference can form a tunneling effect, reduce the hole injection energy level, and improve the hole injection efficiency, thereby improving the electron-hole recombination efficiency of the active layer, which helps to improve the luminescence effect of the light-emitting diode.

[0021] Optionally, the second layer structure is formed of Al x1 Ga (1-x1) N layers, where 0≤x1≤0.1.

[0022] Optionally, the second layer structure is formed of Al x1 Ga (1-x1) N layers, where 0<x1≤0.1.

[0023] Optionally, the second layer structure is formed of a material of GaN.

[0024] As described above, the Al content in the second structure AlGaN layer is further controlled to be less than 10%, or even 0, that is, the second structure layer is a GaN layer, so that its energy gap is close to that of GaN, and a significant energy gap difference is formed with the AlN layer, forming a tunneling effect, which is beneficial to the transition of holes. In addition, the addition of a certain content of Al components is beneficial to improving the lattice defects of the AlGaN material layer, improving the lattice quality of the semiconductor stack, and also beneficial to improving the luminous effect of the light-emitting diode.

[0025] Optionally, the thickness of the second layer structure is 3 to 15 times the thickness of the first layer structure, and the thickness of the second layer structure is 3 to 15 times the thickness of the third layer structure.

[0026] Optionally, the thickness of the second layer structure is between 3 nm and 15 nm.

[0027] Optionally, the thickness of the first layer structure is between 1 nm and 3 nm.

[0028] Optionally, the thickness of the third layer structure is between 1 nm and 3 nm.

[0029] The thickness of each layer structure in the insertion layer can be set to ensure the required energy gap difference between the layers while minimizing the absorption of light by each layer structure and preventing the voltage of the light-emitting diode from being too high.

[0030] Optionally, the thickness of the first structural layer is smaller than the thickness of the third structural layer.

[0031] The thickness of the third structural layer is set to be thicker, which can provide energy to the holes when tunneling through the layer, so that the holes themselves carry more tunneling energy, which is beneficial for the holes to tunnel through the subsequent first structural layer; and the thickness of the first structural layer needs to be set relatively small, so the energy required for the holes to tunnel through the first structural layer can be relatively reduced, so the holes can more easily tunnel through the various material layers into the active layer.

[0032] Optionally, the electron blocking layer is formed of Al x2 Ga (1-x2) N, where 0.1 <X2≤0.5。

[0033] The setting of Al content in the electron blocking layer enables it to have a higher energy level, which can effectively block electrons from overflowing to the P-type semiconductor layer side and increase the number of electrons in the active layer.

[0034] Optionally, X2>X1.

[0035] As described above, the Al component content in the electron blocking layer is made higher than the Al component content in the second layer structure in the insertion layer. x2 Ga (1-x2) The Al content of the N material layer needs to be higher, which is beneficial to improve the Al x2 Ga (1-x2) The energy level of the N material layer enables the electron blocking layer to better block the electrons from overflowing to the P-type semiconductor layer, so that the electrons are more confined in the active layer, increasing the number of electrons in the active layer; x1 Ga (1-x1) The Al component content of the N material layer needs to be lower, so that its energy gap is lower and a more obvious energy gap difference can be formed with the AlN layer, which is more conducive to the formation of a tunneling effect.

[0036] Optionally, the thickness of the electron blocking layer is between 10 nm and 50 nm.

[0037] Optionally, the thickness of the insertion layer is between 5 nm and 25 nm.

[0038] Optionally, the total thickness of the electron blocking layer and the insertion layer is between 15 nm and 70 nm.

[0039] The above-mentioned thickness setting of the electron blocking layer can effectively increase the height of the electron potential barrier, thereby reducing the leakage of electrons from the active area to the P-type layer; at the same time, it will not increase the thickness of the hole potential barrier too much, and will not hinder the injection of holes from the p-type layer to the active area. The thickness setting of the insertion layer enables the insertion layer to form an energy gap difference that is conducive to hole tunneling and is conducive to the transition of holes to the active layer without affecting other properties of the light-emitting diode. In summary, the setting of the total thickness of the electron blocking layer and the insertion layer optimizes the blocking effect on electron overflow and the transition of holes, which is conducive to increasing the recombination efficiency of electrons and holes in the active layer.

[0040] Another embodiment of the present application provides a light-emitting device, which includes a substrate and a plurality of light-emitting units located on the substrate, wherein the light-emitting units include the light-emitting diodes described above in the present application.

[0041] Embodiment 1

[0042] This embodiment provides a light emitting diode, such as Figure 1 As shown, the light emitting diode of this embodiment includes at least a semiconductor stack 200, and the semiconductor stack 200 includes at least a first semiconductor layer 201, an active layer 202, and a second semiconductor layer 203 stacked in sequence from bottom to top. The semiconductor epitaxial stack can be any material that can emit light under the action of voltage, such as GaN, AlGaN, AlInP, AlGaInP, AlGaP, etc. In an optional embodiment, the light emitting diode also includes a substrate 110, and the semiconductor epitaxial stack is located above the substrate 110. The substrate 110 can be a semiconductor substrate such as Si, Ge, etc., or a sapphire substrate.

[0043] Reference Figure 1 , the first semiconductor layer 201 in the semiconductor stack 200 may include n-type impurities (e.g., Si, Ge, Sn), and the second semiconductor layer 203 may include p-type impurities (e.g., Mg, C, Zn). It is understood that the dopants of the first semiconductor layer 201 and the second semiconductor layer 203 may also be opposite to the above. The active layer 202 may include a multi-quantum well structure (MQW), and the active layer 202 may emit a desired wavelength by adjusting the composition ratio of the III-V compound semiconductor.

[0044] Also refer to Figure 1 In this embodiment, an electron blocking layer 204 and an insertion layer 205 are formed between the second semiconductor layer 203 and the active layer 202. The insertion layer 205 is located between the electron blocking layer 204 and the active layer 202. Figure 2As shown, the insertion layer 205 is formed into a multi-layer structure. For example, in the direction from the active layer 202 to the electron blocking layer 204, the insertion layer 205 includes a first layer structure 2051, a second layer structure 2052 and a third layer structure 2053 stacked in sequence. The first layer structure 2051 and the third layer structure 2053 are layer structures formed of the same material, and the energy gap of the materials of the first layer structure 2051 and the third layer structure 2053 is greater than the energy gap of the material of the second layer structure 2052, thereby forming an energy gap difference among the third layer structure 2053, the second layer structure 2052 and the first layer structure 2051, forming a tunneling effect, which is beneficial to the injection of holes.

[0045] In a specific example, the first layer structure 2051 and the third layer structure 2053 are both AlN layers, the second layer structure 2052 is an AlGaN layer, and further, the material of the second layer structure 2052 is Al x1 Ga (1-x1) N, wherein 0≤x1≤0.1. In a further example, x1=0, that is, the material of the second layer structure 2052 is GaN. The energy gap of GaN is about 3.4eV, and AlN has a very wide energy gap, the energy gap size of which is about 6.0eV. Therefore, when x1=0, a significant energy gap can be formed between the third layer structure 2053, the second layer structure 2052 and the first layer structure 2051, which is beneficial for hole transition injection into the active layer 202, thereby improving the hole injection efficiency in the active layer 202. In another example, 0<x1≤0.1, the energy gap of the AlGaN layer is greater than the energy gap of GaN but less than the energy gap of AlN. As defined by the value of x1 above, the Al content in the AlGaN layer is less than or equal to 10%. The low Al content makes the energy gap of the AlGaN layer closer to the energy gap of the GaN layer. Therefore, the AlGaN layer can also form a significant energy gap difference with the AlN layer, forming a tunneling effect, which is also beneficial for the transition of holes. In addition, the addition of a certain content of Al component is beneficial to improving the lattice defects of the AlGaN material layer, improving the lattice quality of the semiconductor stack 200, and also beneficial to improving the light-emitting effect of the light-emitting diode.

[0046] The increase in the material layer and the increase in the thickness of each material layer will produce a certain degree of light absorption phenomenon, and some material layers may also affect the operating voltage of the device. Therefore, in this embodiment, the thickness of the above-mentioned insertion layer 205 and the thickness of each layer structure therein are optimized. Specifically, the thickness of the insertion layer 205 is greater than or equal to 5 nm and does not exceed 50 nm, further greater than or equal to 5 nm and does not exceed 25 nm, and still further, in a preferred embodiment, the thickness of the insertion layer 205 is greater than or equal to 7 nm and does not exceed 15 nm. More specifically, the thickness of the second layer structure 2052 is 3 to 15 times the thickness of the first layer structure 2051, and the thickness of the second layer structure 2052 is 3 to 15 times the thickness of the third layer structure 2053. The thicknesses of the first layer structure 2051 and the third layer structure 2053 can be the same or different. In a further alternative embodiment, the thickness of the first layer structure 2051 ranges from 1 nm to 3 nm, further from 1.5 nm to 2 nm, 2 nm to 3 nm; the thickness of the third layer structure 2053 ranges from 1 nm to 3 nm, further from 1.5 nm to 2 nm, 2 nm to 3 nm; the thickness of the second layer structure 2052 ranges from 3 nm to 15 nm, further from 3 nm to 10 nm, 3 nm to 5 nm, 5 nm to 10 nm, 5 nm to 8 nm, 7 nm to 9 nm, 9 nm to 10 nm, 10 nm to 12 nm, 12 nm to 15 nm. The thickness setting of each layer structure in the insertion layer can minimize the light absorption of each layer structure while ensuring the required energy gap difference between the layers, and at the same time, the voltage of the light-emitting diode will not be too high. Still further, the thickness of the first layer structure 2051 is less than the thickness of the third structure layer. The third structure layer is relatively thick. When tunneling through this layer, energy can be provided to the holes, enabling the holes to carry more tunneling energy by themselves, which is beneficial for the holes to tunnel through the subsequent first structure layer; while the thickness of the first structure layer needs to be set relatively small, so the energy required for the holes to tunnel through the first structure layer will be relatively reduced. Therefore, it is easier for the holes to tunnel through each material layer and enter the active layer. In short, the thickness setting can also adjust the energy gap difference between the material layers, which is more conducive to the transition of holes.

[0047] In an alternative embodiment, the material for forming the above-mentioned electron blocking layer 204 is Al x2 Ga (1-x2) N, where 0.1 < X2 < 0.5, and further 0.2 < X2 < 0.3. The electron blocking layer 204 is a GaN layer containing Al. The setting of the Al content makes the electron blocking layer 204 have a higher energy level, which can effectively block the overflow of electrons to the P-type semiconductor layer side and increase the number of electrons in the active layer.

[0048] In a further embodiment, X2>X1, that is, the content of Al component in the electron blocking layer 204 is higher than the content of Al component in the second layer structure 2052 in the insertion layer 205. The increase of Al component content is beneficial to improve Al x2 Ga (1-x2) The energy level of the N material layer enables the electron blocking layer 204 to better block the electrons from overflowing to the P-type semiconductor layer, so that the electrons are more confined in the active layer 202, and the number of electrons in the active layer 202 is increased. In an optional embodiment, the thickness of the electron blocking layer 204 is between 10nm and 50nm, and the total thickness of the electron blocking layer 204 and the insertion layer 205 is between 15nm and 70nm. The above-mentioned thickness setting of the electron blocking layer 204 can effectively increase the height of the electron barrier, thereby reducing the leakage of electrons from the active area 202 to the P-type layer; at the same time, the thickness of the hole barrier will not be increased too much, and the injection of holes from the p-type layer to the active area 202 will not be hindered. The thickness setting of the insertion layer 205 enables the insertion layer 205 to form an energy gap difference that is conducive to hole tunneling, which is conducive to the transition of holes to the active layer 202. In summary, the setting of the total thickness of the electron blocking layer 204 and the insertion layer 205 optimizes the blocking effect on electron overflow and the transition of holes, which is beneficial to increase the recombination efficiency of electrons and holes in the active layer 202. It can be seen that in this embodiment, through the synergistic effect of the electron blocking layer 204 and the insertion layer 205, on the one hand, it is beneficial to the transition of holes to the active layer 202, and on the other hand, it better prevents electrons from overflowing to the side of the P-type semiconductor layer, thereby better confining electrons and holes in the active layer 202, improving the recombination efficiency in the active layer 202, and improving the luminous efficiency of the light-emitting diode.

[0049] Refer again Figure 1 , the second semiconductor layer 203 includes a P-type hole injection layer 2031 and a P-type ohmic contact layer 2032 formed above the electron blocking layer 204. In an optional embodiment, the P-type hole injection layer 2031 and the P-type ohmic contact layer 2032 are both P-type doped nitride layers, such as GaN layers, and the P-type impurities may include one or a combination of Mg, Zn, Ca, Sr and Ba. In this embodiment, the P-type impurity is preferably Mg. And the doping concentration of the P-type ohmic contact layer 2032 is greater than the doping concentration of the P-type hole injection layer 2031, so that the P-type ohmic contact can form a good ohmic contact with the metal electrode, and the P-type hole injection layer 2031 can provide sufficient holes for radiation recombination.

[0050] Refer again Figure 1The above-mentioned active layer 202 may optionally be a multi-quantum well layer, which includes multiple quantum well layers (Well) and multiple quantum barrier layers (Barrier) grown alternately in a repeated manner, for example, a multi-quantum well structure of GaN / AlGaN, InAlGaN / InAlGaN, InGaN / AlGaN or InGaN / GaN. In this embodiment, the barrier layer in the active layer 202 is GaN and / or AlGaN, and the well layer is InGaN. Among them, the multi-quantum well layer may include 1 to 200 cycles of quantum well layers and quantum barrier layers alternately stacked. As an example, preferably, the multi-quantum well layer 22 includes 5 to 12 cycles of quantum well layers and quantum barrier layers alternately stacked. In addition, the composition and thickness of the well layer in the active layer 202 determine the wavelength of the generated light, and the composition ratio, thickness, etc. of the semiconductor material in the active layer 202 can be adjusted to obtain light radiating different wavelengths. In order to improve the light emitting efficiency of the active layer 202 , it can be achieved by changing the depth of the quantum well, the number of layers, thickness and / or other characteristics of the paired quantum wells and quantum barriers in the active layer 202 .

[0051] In the growth direction of the substrate 100 (ie, Figure 1 In the bottom-to-top direction of the semiconductor stack 200, the first semiconductor layer 201 in the semiconductor stack 200 includes a buffer layer 2011 and an N-type electron injection layer 2012 stacked in sequence. The N-type electron injection layer 2012 may be an N-type doped nitride material layer, such as a GaN layer, which provides electrons by doping N-type impurities. The N-type impurities may include one or a combination of Si, Ge, Sn, Se and Te. In this embodiment, the N-type impurity is preferably Si. Optionally, the N-type electron injection layer 2012 may include a high-doping layer and a low-doping layer, wherein the low-doping layer is located between the active layer 202 and the high-doping layer, thereby better confining the carriers in the active layer 202. The buffer layer 2011 may be an unintentionally doped nitride material layer, such as a GaN layer. Optionally, in order to reduce the dislocation defects between the first semiconductor layer 201 and the active layer 202, a stress release layer 2013 may be formed between the first semiconductor layer 201 and the active layer 202, and the stress release layer 2013 may be a superlattice composite layer of AlGaN / InGaN or GaN / InGaN. The stress release layer 2013 may serve as a transition layer, which can effectively reduce the dislocation defects between the first semiconductor layer 201 and the active layer 202, improve the crystal quality of the semiconductor epitaxial stack 200, and help improve the light-emitting effect of the light-emitting diode. In addition, the stress buffer layer of the superlattice composite structure also helps to improve the mobility of electrons, which is beneficial to improving the electronic transport characteristics of the device and reducing the resistivity.

[0052] like Figure 1As shown, the light emitting diode of this embodiment is also formed with a substrate, which can be a growth substrate for growing the above-mentioned semiconductor stack 200, and the material of the growth substrate can be sapphire, silicon carbide, silicon, gallium arsenide or gallium nitride, etc. The material selection of the substrate can be selected according to the type of the semiconductor stack 200 formed thereon, and the selection principle is that the lattice of the semiconductor epitaxial stack and the substrate can be well matched. For example, when the semiconductor epitaxial stack is AlGaInP material, the substrate selects a GaAs substrate that matches the lattice of the AlGaInP material; when the semiconductor epitaxial stack is GaN material, the substrate selects a sapphire substrate that matches the lattice of the GaN material, etc. This application takes the semiconductor epitaxial stack as AlGaN material and the substrate as a sapphire substrate as an example. The buffer layer 2011 can increase the lattice matching degree between the growth substrate and the above-mentioned AlGaN semiconductor stack 200, reduce the lattice dislocation of the semiconductor stack 200 formed above the substrate, and improve the quality of the semiconductor stack 200. In an optional embodiment, in order to further improve the lattice quality of the semiconductor epitaxial stack above the substrate, the sapphire substrate is a patterned sapphire substrate, and the semiconductor stack 200 is grown above the patterned side of the sapphire substrate.

[0053] In an optional embodiment, the substrate may also be a semiconductor stack 200 that is a bonding substrate. After the growth of the semiconductor stack 200 is completed, it is bonded to the substrate through processes such as removing the growth substrate, transferring, and bonding. At this time, the substrate may also be a sapphire substrate. In order not to destroy or damage the semiconductor epitaxial stack when removing the growth substrate during the transfer of the semiconductor epitaxial stack, a cutoff layer may be formed above the buffer layer 2011, and then the N-type electron injection layer 2012 is grown above the cutoff layer. Afterwards, when the semiconductor epitaxial stack is transferred, for example, when the growth substrate is removed by a solution etching method, the cutoff layer serves as a stop layer for etching, protecting the semiconductor epitaxial stack from being easily damaged by etching, thereby ensuring the crystal quality of the semiconductor stack 200.

[0054] Likewise Figure 1 As shown, optionally, the light emitting diode further comprises an electrode structure, which is formed on one side of the P-type semiconductor layer of the semiconductor stack 200, and the semiconductor stack 200 further forms a mesa structure exposing the first semiconductor layer 201. The electrode structure comprises a first electrode 301 and a second electrode 302, wherein the first electrode 301 is formed above the mesa structure and electrically connected to the first semiconductor layer 201, and the second electrode 302 is formed above the second semiconductor layer 203 and electrically connected to the second semiconductor layer 203.

[0055] In order to verify the light emitting effect of the light emitting diode of this embodiment, the light emitting effect (light power) of the light emitting diode of this embodiment and the light emitting diode of the prior art are compared. Figure 3As shown, in the wavelength band of 460nm-475nm, the optical power of the light emitting diode of the present embodiment is higher than that of the light emitting diode of the prior art, especially in the wavelength band of 465nm-471nm, the optical power of the light emitting diode of the present embodiment is significantly improved, the optical power is above 2.45W, and the highest can reach above 2.6W, while the optical power of the light emitting diode of the prior art is below 2.6W. It can be seen that the optical power of the light emitting diode with the semiconductor epitaxial stack of the present embodiment is significantly improved, and the light emitting effect of the light emitting diode is greatly improved.

[0056] Embodiment 2

[0057] This embodiment provides a light emitting device 500, such as Figure 4 As shown, the light emitting device 500 includes a circuit substrate 501 and a plurality of light emitting units 502 electrically connected to the circuit substrate 501. In this embodiment, the light emitting units 502 are semiconductor light emitting elements provided in the first embodiment. Figure 4 As shown, the circuit substrate 501 has a plurality of groups of pads 505. The electrode structure of each light-emitting unit 502 is electrically connected to a group of pads 505. In addition, a circuit layer 503 is provided in the circuit substrate 501, and the light-emitting unit 502 is electrically connected to the circuit layer 503 via the pads 505. Figure 4 As shown, the light emitting device 500 may further include a housing 504 to protect the light emitting unit 502 from external pollution or damage, while not affecting the light emitting effect of the light emitting unit 502. The above-mentioned arrangement of the wiring layer and the pad area of ​​the light emitting diode of the present application increases the bonding force of the light emitting diode fixed to the above-mentioned pad 505, thereby improving the reliability of the device.

[0058] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A light emitting diode, comprising at least a semiconductor stack, wherein the semiconductor stack comprises a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence, characterized in that: An electron blocking layer is formed between the second semiconductor layer and the active layer, and an insertion layer is formed between the electron blocking layer and the active layer. Along the direction from the active layer to the electron blocking layer, the insertion layer includes a first layer structure, a second layer structure and a third layer structure stacked in sequence, the first layer structure and the third layer structure are AlN layers, and the second layer structure is Al x1 Ga (1-x1) N layers, where x1≥0.

2. The light emitting diode according to claim 1, characterized in that: The second layer structure is formed of Al x1 Ga (1- x1) N layers, where 0≤x1≤0.

1.

3. The light emitting diode according to claim 1, characterized in that: The second layer structure is formed of Al x1 Ga (1- x1) N layers, where 0<x1≤0.

1.

4. The light emitting diode according to claim 1, characterized in that: The second layer structure is formed of GaN.

5. The light emitting diode according to claim 1, characterized in that: The thickness of the second layer structure is 3 to 15 times the thickness of the first layer structure, and the thickness of the second layer structure is 3 to 15 times the thickness of the third layer structure.

6. The light emitting diode according to claim 1, characterized in that: The thickness of the second layer structure is between 3 nm and 15 nm.

7. The light emitting diode according to claim 1, characterized in that: The thickness of the first layer structure is between 1 nm and 3 nm.

8. The light emitting diode according to claim 1, characterized in that: The thickness of the third layer structure is between 1 nm and 3 nm.

9. The light emitting diode according to claim 1, 7 or 8, characterized in that: The thickness of the first structural layer is smaller than the thickness of the third structural layer.

10. The light emitting diode according to claim 1, characterized in that: The electron blocking layer is formed of Al x2 Ga (1- x2) N, where 0.1 <X2≤0.5。 11. The light emitting diode according to claim 10, characterized in that: X2>X1.

12. The light emitting diode according to claim 1, characterized in that: The thickness of the electron blocking layer is between 10 nm and 50 nm.

13. The light emitting diode according to claim 1, characterized in that: The thickness of the insertion layer is between 5 nm and 25 nm.

14. The light emitting diode according to claim 1, characterized in that: The total thickness of the electron blocking layer and the insertion layer is between 15 nm and 70 nm.

15. A light emitting device, characterized in that: The invention comprises a substrate and a plurality of light-emitting units located on the substrate, wherein the light-emitting units comprise the light-emitting diodes according to any one of claims 1 to 14.

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