Light emitting diode and light emitting device

Abstract

The invention discloses a light-emitting diode and a light-emitting device. A second semiconductor layer in the light-emitting diode is a P-type doped layer; wherein the second semiconductor layer at least comprises a P-type transition layer, a P-type space layer and a P-type limiting layer which are stacked in sequence, the P-type transition layer is located between the P-type space layer and the active layer, and the P-type space layer is located between the P-type transition layer and the P-type limiting layer. The P-type space layer and the P-type limiting layer are made of AlxGa (1-x) P materials, wherein x is larger than or equal to 0 and smaller than or equal to 1. The band gap of the AlGaP material ranges from 2.26 eV to 2.48 eV, and the band gap of the AlP is larger than that of the AlInP, the P-type space layer and the P-type limiting layer are arranged to be an AlGaP material system, so that the conduction band of the P-type semiconductor layer and the band order of the multi-quantum well light-emitting layer can be greatly improved, electron overflow can be greatly reduced, non-radiative recombination of electrons in the P-type semiconductor layer is blocked, and the light-emitting efficiency of the light-emitting device is improved. And the internal quantum efficiency and the HC performance of the LED are 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] Light-emitting diodes (LEDs) have the advantages of high contrast, high brightness, low energy consumption, short response time, high reliability and long life, which makes LEDs widely used in many fields, such as high-definition display, lighting, visible light communication and biomedicine.

[0003] AlGaInP-based LEDs use AlGaInP quaternary materials that match the GaAs substrate lattice. The bandgap width can be adjusted from 1.91 to 2.275 eV, and red, orange, yellow, and yellow-green spectrum LEDs can be prepared. Due to the breakthrough and continuous development of metal organic chemical vapor deposition (MOCVD) technology, AlGaInP-based LEDs have become the solid-state light-emitting devices with the highest luminous efficiency in the red to yellow-green spectrum range. The P-type space layer of traditional AlGaInP-based LEDs uses AlGaInP materials that match the GaAs substrate, and the P-type confinement layer uses AlInP materials. By adjusting the atomic concentration ratio of each group III element component, the height of the conduction band and the valence band are adjusted, and by optimizing the band order of the energy band, the electron overflow is limited to the maximum extent, allowing electrons and holes to recombine as fully as possible in the multi-quantum well light-emitting area.

[0004] The AlGaInP material, which is lattice-matched to the GaAs substrate, has a bandgap width ranging from 1.91 to 2.275 eV, and the largest conduction band step is 0.2 eV. Due to material limitations, a large portion of electrons in AlGaInP-based LEDs will cross the conduction band barrier of the P-type space layer, causing electron overflow, increasing the proportion of non-radiative recombination, causing serious self-heating and reducing internal quantum efficiency. In addition, at high temperatures, the number of electrons in high energy states increases, aggravating overflow, and the smaller energy band step of the AlGaInP material also causes the ratio of LED brightness at high and low temperatures (Hot / Cold ratio, HC) to be much lower than that of GaN-based LEDs. Summary of the invention

[0005] In view of the defects and deficiencies of AlGaInP-based 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 application selects and controls semiconductor epitaxial materials to improve the conduction band of the P-type space layer and the P-type confinement layer, thereby significantly improving the conduction band step between the multi-quantum well light-emitting layer and the P-type layer, reducing the overflow degree of high-energy state electrons, and increasing the proportion of radiation recombination of electrons and holes in the multi-quantum well light-emitting area, thereby achieving an improvement in internal quantum efficiency and HC performance, and improving the light-emitting effect of the light-emitting diode.

[0006] To achieve the above-mentioned object and other related objects, the present invention provides a light-emitting diode, which at least comprises a semiconductor stack, wherein the semiconductor stack comprises a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence from bottom to top, wherein the second semiconductor layer is a P-type doped layer; the second semiconductor layer at least comprises a P-type transition layer, a P-type space layer and a P-type confinement layer stacked in sequence, wherein the P-type transition layer is located between the P-type space layer and the active layer, wherein the P-type space layer is located between the P-type transition layer and the P-type confinement layer, and wherein the material forming the P-type space layer comprises Al x Ga (1-x) P material, where 0≤x≤1.

[0007] 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.

[0008] 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:

[0009] The second semiconductor layer in the light-emitting diode of the present invention is a P-type doped layer; wherein the second semiconductor layer at least comprises a P-type transition layer, a P-type space layer and a P-type restriction layer stacked in sequence, the P-type transition layer is located between the P-type space layer and the active layer, the P-type space layer is located between the P-type transition layer and the P-type restriction layer, and the forming materials of the P-type space layer and the P-type restriction layer include Al x Ga (1-x) P material, where 0≤x≤1. The bandgap width of AlGaP material ranges from 2.26eV to 2.48eV, and the bandgap width of AlP is greater than that of AlInP. By setting the P-type space layer and the P-type confinement layer as an AlGaP material system, the present application can greatly improve the conduction band of the P-type semiconductor layer and the band order of the multi-quantum well light-emitting layer, greatly reduce electron overflow, and prevent electrons from non-radiatively recombining inside the P-type semiconductor layer, thereby improving the internal quantum efficiency and HC performance of the LED.

[0010] The P-type confinement layer can further be made of AlP material, which can reduce the absorption of light and help the light to be emitted to the external space, thereby improving the light extraction efficiency of the light-emitting diode. At the same time, there is no need to grow a transition layer between the P-type confinement layer and the P-type window layer, which greatly improves the quality of the P-side epitaxial crystal growth. In addition, the thickness design of the above-mentioned layers of the second semiconductor layer can reduce the operating voltage of the light-emitting diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 Shown is a schematic diagram of the structure of a light emitting diode provided in Example 1 of the present application.

[0012] Figure 2 Display as Figure 1 Schematic diagram of the structure of the semiconductor epitaxial stack of the light-emitting diode.

[0013] Figure 3 and Figure 4 The diagram shows a comparison of the conduction band energy levels of the light emitting diode of the present application and the light emitting diode in the prior art.

[0014] Figure 5 Shown is a schematic structural diagram of a flip-chip light emitting diode in an optional embodiment of the present application.

[0015] Figure 6 Shown is a schematic structural diagram of a Micro LED in another optional embodiment of the present application.

[0016] Figure 7 A schematic diagram showing the structure of the light-emitting device provided in the second embodiment of the present application is shown.

[0017] Reference numerals

[0018] 110, substrate; 120, semiconductor stack; 121, first semiconductor layer; 1211, N-type ohmic contact layer; 1212, N-type window layer; 1213, N-type confinement layer; 1214, N-type space layer; 122, active layer; 123, second semiconductor layer; 1231, P-type transition layer; 1232, P-type space layer; 1233, P-type confinement layer; 1234, P-type window layer; 1235, P-type ohmic contact layer; 130, bonding layer; 141, first electrode; 142, second electrode; 150, current diffusion layer; 160, insulating protection layer; 161, first through hole; 162, second through hole.

[0019] 200, light-emitting device; 201, circuit substrate, 202, light-emitting unit; 203, circuit layer; 204, housing; 205, solder pad. DETAILED DESCRIPTION

[0020] 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.

[0021] 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.

[0022] Embodiment 1

[0023] 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 120, and the semiconductor stack 120 includes at least a first semiconductor layer 121, an active layer 122, and a second semiconductor layer 123 stacked in sequence from top to bottom. 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 110 such as Si, Ge, etc., or a metal substrate 110 such as Cu.

[0024] Reference Figure 1 , the first semiconductor layer 121 in the semiconductor stack 120 may include n-type impurities (e.g., Si, Ge, Sn), and the second semiconductor layer 123 may include p-type impurities (e.g., Mg, C, Zn). It is understood that the dopants of the first semiconductor layer 121 and the second semiconductor layer 123 may also be opposite to the above. The active layer 122 may include a multi-quantum well structure (MQW), and the active layer 122 may emit a desired wavelength by adjusting the composition ratio of the III-V compound semiconductor.

[0025] In this embodiment, Figure 2 As shown, in the direction gradually away from the active layer 122 (ie Figure 2 In the bottom-to-top direction of the semiconductor stack 120, the second semiconductor layer 123 in the semiconductor stack 120 at least includes a P-type transition layer 1231, a P-type space layer 1232, and a P-type confinement layer 1233 stacked in sequence, wherein the P-type transition layer 1231 is adjacent to the active layer 122, and the material forming the P-type transition layer 1231 includes AlGaInP material. Further, the material forming the P-type transition layer 1231 is (Al a Ga (1-a) ) b In cP gradient material layer, wherein 0≤a≤1, 0<b<1, 0<c<1; further, wherein 0.1≤a≤1, 0.5≤b≤0.9, 0.1≤c≤0.5, and in the direction away from the active layer 122, the value of a gradually decreases, the value of b gradually increases, and the value of c gradually decreases. That is, in the direction away from the active layer 122, the material of the P-type transition layer 1231 is composed of (Al 0.9 Ga 0.1 ) 0.5 In 0.5 P gradually changes to (Al 0.1 Ga 0.9 ) 0.9 In 0.1 In addition, in order to reduce the absorption of light, the thickness of the P-type transition layer 1231 is set to be between between, further, between

[0026] In an optional embodiment, the materials forming the P-type space layer 1232 and the P-type confinement layer 1233 include Al x Ga (1-x) P material, where 0≤x≤1. Further, in the direction gradually away from the active layer 122, in the P-type space layer 1232, Al x Ga (1-x) The value of x in the P material gradually increases. Further, the value of x gradually increases from 0 to 1, that is, in the direction gradually away from the active layer 122, the material forming the P-type space layer 1232 can be gradually changed from GaP material to AlP material. As described above, in the direction gradually away from the active layer 122, the material of the P-type transition layer 1231 is changed from (Al 0.9 Ga 0.1 ) 0.5 In 0.5 P gradually changes to (Al 0.1 Ga 0.9 ) 0.9 In 0.1 P, that is, on the side adjacent to the P-type space layer 1232, the material of the P-type transition layer 1231 gradually changes to (Al 0.1 Ga 0.9 ) 0.9 In 0.1 P material, and the P-type space layer 1232 adjacent to the P-type transition layer 1231 is formed of GaP. The GaP material is 0.1 Ga 0.9 ) 0.9 In 0.1The P material composition is similar and the lattice matching is high, which avoids more lattice defects caused by excessive lattice mismatch, and is conducive to forming an epitaxial structure with good crystal quality. In addition, also for the consideration of light absorption, the thickness of the above-mentioned P-type space layer 1232 is set to be between Furthermore, between

[0027] In an optional embodiment, the material forming the P-type confinement layer 1233 includes an AlP material. As described above, in the direction gradually away from the active layer 122, the material forming the P-type space layer 1232 can be gradually changed from a GaP material to an AlP material, that is, on the side adjacent to the above-mentioned P-type confinement layer 1233, the material forming the P-type space layer 1232 is basically an AlP material, which is basically the same as the material forming the P-type confinement layer 1233, so the energy bands between the two can achieve a smooth transition. In addition, the bandgap width of the AlGaP material ranges from 2.26eV to 2.48eV, and the bandgap width of AlP is greater than that of AlInP, such as Figure 3 and Figure 4 As shown, by setting the P-type space layer 1232 and the P-type confinement layer 1233 to an AlGaP material system, preferably, setting the P-type space layer 1232 to an Al x Ga (1-x) P gradient material layer, setting the P-type confinement layer 1233 as an AlP material layer can greatly improve the band order of the P-type layer conduction band and the multi-quantum well light-emitting layer, greatly reduce electron overflow, prevent electrons from non-radiative recombination inside the P-type layer, and improve the internal quantum efficiency and HC performance of the LED.

[0028] In the second semiconductor layer 123, the above-mentioned P-type confinement layer 1233 is the main P-type doping layer. Due to the diffusion effect of P-type impurities, a certain concentration of P-type impurities will also exist in the P-type space layer 1232 and the P-type transition layer 1231. Therefore, the P-type space layer 1232 and the P-type transition layer 1231 are formed as unintentionally doped layers. The doping elements in the P-type confinement layer 1233 can be P-type impurities such as Mg, C, or Zn. In this embodiment, the doping concentration of P-type impurities in the P-type confinement layer 1233 is between 1.0E+16atom / cm 3 ~1.0E+19atom / cm 3 The thickness of the P-type confinement layer 1233 is 0.1 μm to 10 μm, and further, between 2 μm and 8 μm. The setting of the doping concentration and thickness ensures that the P-type confinement layer 1233 has a sufficiently high and wide conduction band barrier, effectively limiting the overflow of electrons under large current and high temperature.

[0029] Also refer to Figure 2The second semiconductor layer 123 also includes a P-type window layer 1234 and a P-type ohmic contact layer 1235 formed on the P-type confinement layer 1233, wherein the material for forming the P-type window layer 1234 is GaP material, and the lattice constant of the GaP material is similar to that of the AlP material for forming the P-type confinement layer 1233, and the lattice matching between the two is good, so there is no need to form a transition material layer between the two, which ensures the crystal growth quality of the P-type window layer and helps to reduce defects and light absorption. The P-type ohmic contact layer 1235 also uses GaP material, which helps to enhance the ohmic contact with the conductive material formed subsequently, enhance the current expansion capability, and improve the electrical performance of the light-emitting diode.

[0030] Refer again Figure 2 The active layer 122 may be a multi-quantum well layer, which includes an AlGaInP quantum well layer and an AlGaInP quantum barrier layer grown alternately, and the Al content in the AlGaInP quantum well layer and the AlGaInP quantum barrier layer is different. The multi-quantum well layer may include 1 to 200 cycles of AlGaInP quantum well layers and AlGaInP quantum barrier layers alternately stacked. As an example, the multi-quantum well layer 22 includes 5 cycles of AlGaInP quantum well layers and AlGaInP quantum barrier layers alternately stacked.

[0031] In the direction gradually away from the active layer 122 (ie, Figure 2 In the direction from top to bottom in the semiconductor stack 120, the first semiconductor stack 120 in the semiconductor stack 120 includes an N-type space layer 1214, an N-type confinement layer 1213, an N-type window layer 1212 and an N-type ohmic contact layer 1211 stacked in sequence. The N-type space layer 1214, the N-type confinement layer 1213 and the N-type window layer 1212 are also made of AlGaInP material, for example, the N-type space layer 1214 is made of AlGaInP material, the N-type confinement layer 1213 is made of AlInP material, and the N-type window layer 1212 is made of AlGaInP material. The N-type ohmic contact layer 1211 is made of GaAs material.

[0032] It is understandable that when making the above-mentioned light-emitting diode, the above-mentioned semiconductor epitaxial stack is first formed on the growth substrate, and then the semiconductor epitaxial stack is transferred to the substrate 110 by a suitable transfer process such as bonding. When growing the semiconductor epitaxial stack, 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 semiconductor stack 120 formed thereon, and the lattice of the semiconductor epitaxial stack and the substrate can be well matched as the selection principle. 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 AlGaInP material and the substrate as a GaAs substrate as an example. In order to increase the lattice matching degree between the growth substrate and the above-mentioned AlGaInP semiconductor stack 120 and improve the quality of the crystal growth, a GaAs buffer layer is first formed on the growth substrate to reduce the lattice dislocation of the semiconductor stack 120 formed on the substrate and improve the quality of the semiconductor stack 120. In addition, in order to avoid destroying or damaging the semiconductor epitaxial stack when the growth substrate is removed after the semiconductor epitaxial stack is transferred, a stop layer can also be formed on the above-mentioned buffer layer, and then the above-mentioned first semiconductor layer 121, active layer 122 and second semiconductor layer 123 are sequentially grown on the stop layer. Afterwards, when the semiconductor epitaxial stack is transferred, for example, when the growth substrate is removed by a solution etching method, the stop layer serves as an etching stop layer to protect the semiconductor epitaxial stack from being easily damaged by etching and ensure the crystal quality of the semiconductor stack 120.

[0033] Refer again Figure 1 The substrate 110 and the semiconductor of the light emitting diode of this embodiment further include a bonding layer 130, which may be a metal layer. In an optional embodiment, a metal reflection layer may be formed between the bonding layer 130 and the semiconductor epitaxial stack, and the metal reflection layer reflects the light radiated by the semiconductor epitaxial stack to the first semiconductor layer 121. In order to further improve the light emitting effect of the light emitting diode, in an optional embodiment, the surface of the N-type semiconductor layer as the light emitting surface may also be formed as a rough surface.

[0034] Likewise Figure 1 As shown, optionally, the light emitting diode is formed into a vertical structure, which also includes an electrode structure, which includes a first electrode 141 and a second electrode 142, the first electrode 141 is formed above the first semiconductor layer 121, and the second electrode 142 is formed below the substrate 110, and is electrically connected to the second semiconductor layer 123 via the substrate 110 and the metal reflective layer.

[0035] In an alternative embodiment of this embodiment, the light emitting diode may also be formed into a flip-chip structure. Figure 5 As shown, the flip-chip light emitting diode also includes a substrate 110 and a semiconductor stack 120 formed on the substrate 110. The substrate 110 is a transparent substrate, such as a sapphire substrate, which has good light transmittance, which is conducive to the light emitting diode emitting light on the side of the substrate 110. The semiconductor stack 120 at least includes a first semiconductor layer 121, an active layer 122, and a second semiconductor layer 123 stacked in sequence from bottom to top. The electrode structure 140 is formed above the second semiconductor layer 123, specifically, formed above the insulating protection layer 160 above the second semiconductor layer 123. The electrode structure 140 includes a first electrode 141 electrically connected to the first semiconductor layer 121 and a second electrode 142 electrically connected to the second semiconductor layer 123. The first electrode 141 and the second electrode 142 are electrically connected to the first semiconductor layer 121 and the second semiconductor layer 123 through a first through hole 161 and a second through hole 162 penetrating the insulating protection layer 160, respectively. In order to increase the current diffusibility on one side of the second semiconductor layer 123, a current diffusion layer 150 is further formed on the second semiconductor layer 123, and the current diffusion layer 150 may be a transparent conductive layer, such as ITO, IZO, etc. The above-mentioned insulating protection layer 160 forms a reflective structure, such as a DBR structure with SiO2 / TiO2 alternately stacked, to reflect the light radiated by the active layer 122 to the substrate 110 side for emission, thereby improving the light emission effect of the light emitting diode.

[0036] In an alternative embodiment of this embodiment, the light emitting diode may also be a Micro LED. Figure 6 As shown, the Micro LED also includes a semiconductor stack 120, and the semiconductor stack 120 at least includes a first semiconductor layer 121, an active layer 122, and a second semiconductor layer 123 stacked in sequence from bottom to top. The electrode structure 140 is also formed above the second semiconductor layer 123, specifically, formed above the insulating protection layer 160 above the second semiconductor layer 123. The side of the first semiconductor layer 121 away from the active layer 122 is the light-emitting surface of the Micro LED. Furthermore, in order to increase the light-emitting effect of the Micro LED, the light-emitting surface of the first semiconductor layer 121 is formed as a roughened structure. The electrode structure 140 includes a first electrode 141 electrically connected to the first semiconductor layer 121 and a second electrode 142 electrically connected to the second semiconductor layer 123. The first electrode 141 and the second electrode 142 are electrically connected to the first semiconductor layer 121 and the second semiconductor layer 123 respectively through a first through hole 161 and a second through hole 162 that penetrate the insulating protection layer 160. Similarly, Figure 6As shown, in order to increase the current diffusivity on one side of the second semiconductor layer 123, a current diffusion layer 150 is further formed on the second semiconductor layer 123, and the current diffusion layer 150 can be a transparent conductive layer, such as ITO, IZO, etc. The above-mentioned insulating protection layer 160 forms a reflective structure, such as a DBR structure with SiO2 / TiO2 alternately stacked, to reflect the light radiated by the active layer 122 to the substrate 110 side for emission, thereby improving the light emission effect of the light emitting diode.

[0037] Embodiment 2

[0038] This embodiment provides a light emitting device 200, such as Figure 7 As shown, the light emitting device 200 includes a circuit substrate 201 and a plurality of light emitting units 202 electrically connected to the circuit substrate 201. In this embodiment, the light emitting units 202 are semiconductor light emitting elements provided in the first embodiment. Figure 7 As shown, the circuit substrate 201 has a plurality of groups of pads 205. The electrode structure of each light-emitting unit 202 is electrically connected to a group of pads 205. In addition, a circuit layer 203 is provided in the circuit substrate 201, and the light-emitting unit 202 is electrically connected to the circuit layer 203 via the pads 205. Figure 7 As shown, the light emitting device 200 may further include a housing 204 to protect the light emitting unit 202 from external pollution or damage, while not affecting the light emitting effect of the light emitting unit 202. 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 205, thereby improving the reliability of the device.

[0039] 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, wherein the second semiconductor layer is a P-type doped layer; characterized in that: The second semiconductor layer at least includes a P-type transition layer, a P-type space layer and a P-type confinement layer stacked in sequence, the P-type transition layer is located between the P-type space layer and the active layer, the P-type space layer is located between the P-type transition layer and the P-type confinement layer, and the forming materials of the P-type space layer and the P-type confinement layer include Al x Ga (1-x) P material, where 0≤x≤1.

2. The light emitting diode according to claim 1, characterized in that: The thickness of the P-type space layer is between 3. The light emitting diode according to claim 1, characterized in that: In the direction gradually away from the active layer, the material Al forming the P-type space layer x Ga (1-x) In P material, the value of x gradually increases.

4. The light emitting diode according to claim 1 or 2, characterized in that: In a direction gradually away from the active layer, the material forming the P-type space layer gradually changes from GaP material to AlP material.

5. The light emitting diode according to claim 1, characterized in that: The material forming the P-type confinement layer includes AlP material.

6. The light emitting diode according to claim 1, characterized in that: The doping concentration of the P-type confinement layer is 1.0E+16atom / cm 3 ~1.0E+19atom / cm 3 .

7. The light emitting diode according to claim 1, characterized in that: The thickness of the P-type confinement layer is 0.1 μm to 10 μm.

8. The light emitting diode according to claim 1, characterized in that: The material forming the P-type transition layer includes AlGaInP material.

9. The light emitting diode according to claim 8, characterized in that: The thickness of the P-type transition layer is between 10. The light emitting diode according to claim 8, characterized in that: The material for forming the P-type transition layer is (Al a Ga (1-a) ) b In c P gradient material layer, wherein 0≤a≤1, 0<b<1, 0<c<1.

11. The light emitting diode according to claim 10, characterized in that: The material for forming the P-type transition layer is (Al a Ga (1-a) ) b In c P gradient material layer, where 0.1≤a≤1, 0.5≤b≤0.9, 0.1≤c≤0.

5.

12. The light emitting diode according to claim 11, characterized in that: In a direction gradually moving away from the active layer, the value of a gradually decreases, the value of b gradually increases, and the value of c gradually decreases.

13. The light emitting diode according to claim 1, characterized in that: The second semiconductor layer further includes a P-type window layer formed above the P-type confinement layer and a P-type ohmic contact layer located above the P-type window layer.

14. The light emitting diode according to claim 1, characterized in that: The first semiconductor layer is an N-type doped layer, and in a direction gradually away from the active layer, the first semiconductor layer at least includes an N-type space layer, an N-type confinement layer, an N-type window layer and an N-type ohmic contact layer stacked in sequence.

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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