Light emitting diode and light emitting device

Abstract

The invention provides a light-emitting diode and a light-emitting device. The light-emitting diode comprises an N-type semiconductor layer, an active layer and a P-type semiconductor layer which are stacked in sequence, the P-type semiconductor layer comprises a P-type insertion layer located on the active layer, and the Al component in the P-type insertion layer is not lower than 50%; the P-type contact layer is located on the P-type insertion layer, the P-type contact layer is of a P-type doped superlattice structure, and the P-type doping concentration is not lower than 1 * 1019 atom / cm < 3 >. According to the technical scheme, the P-type insertion layer is arranged to be a high-Al component layer to obtain a high-resistance structure in the vertical direction so as to improve the transverse expansion capacity of current, the P-type contact layer is a superlattice structure layer with high doping concentration, low driving voltage can be achieved, and through the synergistic effect of the P-type insertion layer and the P-type contact layer, the driving performance of the device is improved. Therefore, the device achieves high brightness and high luminous efficiency output while obtaining low working voltage, and the comprehensive performance is remarkably improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, and in particular to a light-emitting diode and a light-emitting device. Background Technology

[0002] Gallium nitride (GaN)-based light-emitting diodes (LEDs) are widely used as a new generation of solid-state lighting sources due to their high efficiency, energy saving, and environmental friendliness. The epitaxial structure of this LED includes a P-type contact layer, which is crucial for hole injection and forming an ohmic contact with the upper metal electrode. To reduce contact resistance and device driving voltage, a high concentration of magnesium (Mg) is typically applied to the P-type contact layer. While high doping concentration is beneficial for forming an ohmic contact, it also causes the injected current to concentrate near the electrode, resulting in current congestion and reducing the effective light-emitting area of ​​the device, thus limiting further increases in light output power. Furthermore, excessively high Mg doping concentrations introduce a large number of defect levels into the GaN crystal. These defect levels, acting as non-radiative recombination centers, strongly absorb photons from the active layer, leading to a decrease in the external quantum efficiency and brightness of the LED.

[0003] Therefore, it is necessary to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0004] In view of the defects and deficiencies existing in the prior art, the purpose of this application is to provide a light-emitting diode and a light-emitting device to solve one or more of the above-mentioned technical problems.

[0005] In a first aspect, a light-emitting diode is provided, comprising an N-type semiconductor layer, an active layer, and a P-type semiconductor layer stacked sequentially; the P-type semiconductor layer comprising:

[0006] A P-type insertion layer is located above the active layer, wherein the Al composition in the P-type insertion layer is not less than 50%.

[0007] A P-type contact layer is located above the P-type insertion layer. The P-type contact layer is a P-type doped superlattice structure or an In-type doped superlattice structure. x Al y Ga 1-x-y N, 0≤x≤0.1, 0≤y≤1; wherein the P-type doping concentration is not less than 1×10 19 atom / cm 3 .

[0008] Secondly, a light-emitting device is provided, the light-emitting device comprising:

[0009] Packaging substrate;

[0010] At least one light-emitting diode is disposed on the surface of the packaging substrate, and the packaging substrate and the electrode structure of the light-emitting diode are electrically connected; the light-emitting diode is a light-emitting diode provided by any of the above technical solutions.

[0011] Compared with the prior art, the light-emitting diode and light-emitting device provided in this application have at least the following beneficial effects:

[0012] In this application, the P-type semiconductor layer includes a P-type insertion layer and a P-type contact layer. The P-type insertion layer is configured as a high-Al composition layer to obtain a high-resistance structure in the vertical direction, which can improve the lateral spread of current. Furthermore, the high-Al layer can generate a polarization effect with the low-Al layer in contact with it, which reduces the lateral resistance through polarization, increases the horizontal spread distance of injected carriers, and thus increases the spread area of ​​the injected current, ultimately increasing the effective light-emitting area of ​​the LED device. Simultaneously, the P-type contact layer is a highly doped superlattice structure layer, enabling low driving voltage. Through the synergistic effect of the P-type insertion layer and the P-type contact layer, the device achieves high brightness and high luminous efficiency output while obtaining a low operating voltage, resulting in a significant improvement in overall performance. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Unless otherwise specified, the positional relationships shown in the drawings in the following description are based on the direction in which the components are drawn in the figure.

[0014] Figure 1 The diagram shown is a cross-sectional view of the flip-chip structure light-emitting diode provided in this application;

[0015] Figure 2 The diagram shown is a cross-sectional structural schematic of the P-type semiconductor layer provided in this application.

[0016] Figure 3 The diagram shown is a cross-sectional structural schematic of the P-type contact layer provided in this application.

[0017] Figure 4 The diagram shown is a cross-sectional view of a light-emitting diode with a standard mounting structure provided in this application;

[0018] Figure 5 The diagram shown is a cross-sectional view of a light-emitting diode with a vertical structure provided in this application;

[0019] Figure 6The diagram shown is a schematic diagram of the light-emitting device provided in this application.

[0020] List of reference numerals in the attached diagram:

[0021] 100 substrate 200 Buffer layer 300 N-type semiconductor layer 400 Active layer 500 P-type semiconductor layer 510 First P-type layer 520 Second P-type layer 530 Third P-type layer 540 P-type insertion layer 550 P-type contact layer 551 First sub-layer 552 Second sub-layer 600 transparent conductive layer 700 Insulation layer 810 First electrode 820 Second electrode 900 conductive substrate 10 Light-emitting device 101 Packaging substrate 102 Light-emitting element Detailed Implementation

[0022] In existing technologies, high P-type doping is beneficial for reducing the driving voltage and decreasing photon absorption by the P-contact layer. However, high doping also creates a large number of defect energy levels, which absorb photons emitted by the LED's multiple quantum wells, leading to a decrease in LED luminous efficiency, i.e., a decrease in brightness. Based on the technical problems and contradictions mentioned in the background, this application provides a light-emitting diode (LED) comprising an N-type semiconductor layer, an active layer, and a P-type semiconductor layer stacked sequentially; the P-type semiconductor layer includes:

[0023] A P-type insertion layer is located above the active layer, wherein the Al composition in the P-type insertion layer is not less than 50%.

[0024] A P-type contact layer is located above the P-type insertion layer. The P-type contact layer is a P-type doped superlattice structure or an In-type doped superlattice structure. x Al y Ga 1-x-y N, 0≤x≤0.1, 0≤y≤1; wherein the P-type doping concentration is not less than 1×10 19 atom / cm 3 By setting a high-Al-content P-type insertion layer and a highly doped superlattice P-type contact layer, the high-Al-content P-type insertion layer exhibits high resistance in the vertical direction, suppressing the vertical concentration injection of current and forcing the current to spread in the horizontal direction, thereby increasing the light-emitting area. The P-type doped superlattice structure forms a two-dimensional conductive channel through the polarization effect, further reducing the lateral resistance and improving the current spreading efficiency.

[0025] In some embodiments, the P-type insertion layer is an AlN layer or an AlGaN layer. AlN and AlGaN have a high Al content, which can provide high resistance in the vertical direction and promote carrier migration in the horizontal direction, thereby improving current spreading efficiency.

[0026] In some embodiments, the thickness of the P-type insertion layer is between 0.5 nm and 4.0 nm. A suitable thickness ensures high resistance characteristics while avoiding the reduction in current spreading efficiency caused by excessive thickness.

[0027] In some embodiments, the Al content of the P-type insertion layer is higher than that of the P-type contact layer. The high Al content of the P-type insertion layer ensures good lateral current spread capability, while the relatively low Al content of the P-type contact layer results in lower bulk resistance, which is beneficial for forming good ohmic contact with structures such as electrodes.

[0028] In some embodiments, the superlattice structure is a structure with a first sublayer and a second sublayer arranged periodically, wherein the Al content of the first sublayer is greater than that of the second sublayer. Superlattice structures with different Al content can generate a strong polarized electric field, promoting the horizontal migration of charge carriers and thus reducing contact resistance.

[0029] In some embodiments, the first sublayer is closer to the active layer than the second sublayer. The second sublayer has a relatively low Al content, weaker energy levels, and better overall structural quality.

[0030] In some implementations, the first sublayer comprises AlGaN or AlInGaN, and the second sublayer comprises GaN or InGaN.

[0031] In some implementations, the thickness ratio of the first sublayer to the second sublayer is between 1:1 and 1:5. Further optimization of the polarization electric field intensity and distribution improves carrier mobility.

[0032] In some embodiments, the superlattice structure comprises 2 to 18 periodically arranged structural layers.

[0033] In some embodiments, the superlattice structure is one or more of AlGaN / GaN superlattice, AlGaN / InGaN superlattice, or AlInGaN / InGaN superlattice.

[0034] In some embodiments, the P-type contact layer is Mg-doped with a doping concentration between 1 × 10⁻⁶. 20 atom / cm 3 Up to 5×10 21 atom / cm 3 P-type doping within this concentration range can effectively reduce the driving voltage while avoiding increased photon absorption caused by excessive doping.

[0035] In some embodiments, the thickness of the P-type contact layer is between 1 nm and 10 nm. This achieves a performance balance between ensuring good ohmic contact and the increased resistance resulting from increased thickness.

[0036] In some embodiments, the P-type semiconductor layer further includes a P-type structure layer located between the active layer and the P-type insertion layer, the P-type structure layer comprising a first P-type layer, a second P-type layer, and a third P-type layer stacked sequentially; wherein,

[0037] The Al component content in the second P-type layer is greater than the Al component content in the first P-type layer;

[0038] The Al content in the second P-type layer is greater than that in the third P-type layer. By adjusting the Al content of each layer in the P-type structure, the hole injection path can be further optimized, and the current congestion effect can be reduced.

[0039] In some embodiments, the material of the first P-type layer is GaN or AlGaN; the material of the second P-type layer is AlGaN; and the material of the third P-type layer is GaN.

[0040] This application also provides a light-emitting device, the light-emitting device comprising:

[0041] Packaging substrate;

[0042] At least one light-emitting diode (LED) is disposed on the surface of the encapsulation substrate, and the encapsulation substrate and the electrode structure of the LED are electrically connected; the LED is any of the LEDs provided in the above-described technical solutions. This light-emitting device achieves high brightness and high luminous efficiency output while operating at low voltage, resulting in a significant improvement in overall performance compared to existing products.

[0043] The following specific embodiments illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0044] The composition and dopants of each layer in the semiconductor laser element described in this application can be analyzed using any suitable method, such as secondary ion mass spectrometry (SIMS). The thickness of each layer in the semiconductor laser element described in this application can be analyzed using any suitable method, such as transmission electron microscopy (TEM) or scanning electron microscopy (SEM), in conjunction with, for example, the depth positions of each layer on a SIMS image.

[0045] For ease of description, the direction from the N-type semiconductor layer 300 to the P-type semiconductor layer 400 is defined as upward, and the opposite direction is defined as downward.

[0046] This embodiment provides a light-emitting diode (LED), see [link]. Figures 1 to 5 The light-emitting diode includes at least a substrate 100 and an epitaxial structure located above the substrate 100. The epitaxial structure includes a buffer layer 200, an N-type semiconductor layer 300, an active layer 400, a P-type semiconductor layer 500, and related electrode structures disposed thereon, which are stacked sequentially. The specific structure and technical solution of the light-emitting diode provided in this embodiment will be described in detail below.

[0047] See Figure 1 The substrate 100 can be one or any combination of sapphire substrate, silicon carbide substrate, silicon substrate, gallium nitride substrate, or aluminum nitride substrate. The front side of the substrate 100 is the growth surface of the epitaxial structure. As an example, using a sapphire substrate or a patterned sapphire substrate as the substrate 100 is beneficial for improving the light propagation path and enhancing the luminous efficacy and luminous intensity of the LED.

[0048] See also Figure 1 A buffer layer 200 is disposed on the front side of the substrate 100, for example, by depositing GaN material on the substrate 100 using methods such as metal-organic chemical vapor deposition (MOCVD). The buffer layer 200 is typically an undoped GaN material (u-GaN) layer, whose main function is to act as a transition layer to achieve lattice matching between the substrate 100 and the epitaxial structure. In heteroepitaxial structures, such as those where an N-type GaN layer 200 and a multi-quantum-well light-emitting layer are grown on a sapphire substrate, there are lattice mismatch and thermal mismatch issues between the substrate 100 and the epitaxial structure. u-GaN provides a transition layer between the two, which can improve the lattice matching between the substrate and the N-type semiconductor layer 300, reduce defects, and on the one hand, help release and buffer this stress to ensure the stability of the entire epitaxial structure. On the other hand, its low-resistivity property can ensure that electrons are smoothly injected from the N electrode into the active layer 400, thereby improving the overall electrical and structural performance of the device. Furthermore, the thickness of the buffer layer 200 is 1.5 μm to 3.0 μm.

[0049] See also Figure 1An N-type semiconductor layer 300 is disposed on the buffer layer 200, which may be any material layer selected from AlGaN, AlInN, AlInGaN, or GaN. Further, the N-type semiconductor layer 300 may also be configured as multiple sub-layers with different doping concentrations. For example, a highly doped N-type sub-layer may be disposed near the active layer 400 to achieve better ohmic contact with the electrode structure, while a relatively lightly doped N-type layer may be disposed near the buffer layer 200 to obtain a better epitaxial crystal structure and product quality. Further, the N-type semiconductor layer 300 is an N-type AlGaN layer. Further, the thickness of the N-type semiconductor layer 300 is 2.0 μm to 4.0 μm.

[0050] See also Figure 1 The active layer 400 provides light radiation for electron-hole recombination. Different material compositions or ratios can be selected depending on the emission wavelength, typically using group III to group V compound semiconductor materials, such as at least one of InGaN / GaN, InGaN / InGaN, GaN / AlGaN, InAlGaN / GaN, GaAs(InGaAs) / AlGaAs, or GaP(InGaP) / AlGaP. The structure of the active layer 400 can be a periodic structure of a single quantum well or multiple quantum wells, consisting of quantum wells and barrier layers. As an example, for a blue-green light-emitting diode, its active layer 400 employs a periodically alternating multiple quantum well structure. Specifically, the active layer 400 includes multiple periodic barrier layers and potential well layers, wherein the barrier layer is a GaN layer or an AlGaN layer, and the potential well layer is an InGaN layer. By adjusting the composition of the potential well layer, the emission wavelength can be controlled within the blue to green light range.

[0051] See Figures 1 to 5 A P-type semiconductor layer 500 is disposed on the active layer 400. The P-type semiconductor layer 500 is doped with one or more of the elements selected from Mg, Zn, Ca, Sr, or Ba. The P-type semiconductor layer 500 can be configured as multiple sublayers with different doping concentrations and Al content. This embodiment uses a Mg-doped P-type semiconductor layer 500 for detailed technical explanation. The P-type semiconductor layer 500 includes a P-type structure layer located on and in direct contact with the active layer 400. Further, the portion of the P-type semiconductor layer 500 near the active layer 400 is a P-type structure layer with a lower Al content, and the portion near the upper electrode structure consists of a P-type insertion layer 540 and a P-type contact layer 550 located on the P-type insertion layer 540.

[0052] In an optional embodiment, the P-type structure layer can be a uniformly composed and doped P-type layer, such as P-type GaN or P-type AlGaN. The Mg doping concentration of the P-type structure layer is controlled at 1 × 10⁻⁶. 19 atom / cm 3Up to 1×10 20 atom / cm 3 Within this range, sufficient hole carrier concentration can be provided to reduce resistance while avoiding crystal quality degradation due to excessive doping concentration. When the P-type structure layer is a GaN material layer, the high-Al content P-type insertion layer 540 above it will generate a polarization effect with the GaN material layer. This polarization can reduce lateral resistance and increase the horizontal expansion distance of injected carriers, thereby increasing the expansion area of ​​the injected current, which in turn increases the effective light-emitting area of ​​the LED device. When the P-type structure layer is an AlGaN material layer, its Al content is between 1% and 20% to provide a sufficient concentration of effective holes. Furthermore, the thickness of the P-type structure layer is 50nm to 150nm to ensure that it completes its hole transport and basic blocking functions, while avoiding a significant increase in series resistance due to excessive layer thickness.

[0053] In an optional embodiment, the P-type structure layer can be a P-type layer with a gradual change in composition and doping. For example, the Al composition gradually decreases from the side closer to the active layer 400 to the side closer to the P-type insertion layer 540. This facilitates hole injection into the active layer 400 and effectively blocks electrons through the side with higher Al composition. Furthermore, the thickness of the P-type structure layer is 50 nm to 150 nm.

[0054] In an optional embodiment, the P-type structure layer can be a stack with two sub-structure layers, such as a lower P-type structure layer and an upper P-type structure layer stacked sequentially. The lower P-type structure layer, serving as the layer in contact with the active layer 400, is made of P-type AlGaN. The Al content of the lower P-type structure layer is between 5% and 20%, its thickness is between 15 nm and 60 nm, and the Mg doping concentration is controlled at 1 × 10⁻⁶. 19 atom / cm 3 Up to 5×10 19 atom / cm 3 Within the specified range. The upper layer of the P-type structure is made of P-type GaN or P-type AlGaN with a low Al content, such as Al content <5%. The lower layer of the P-type structure provides a path with high hole mobility and low resistance, ensuring that holes can efficiently pass through the P-type region. The thickness of the upper layer of the P-type structure is between 20 nm and 80 nm. The Mg doping concentration of this layer can be equal to or slightly higher than that of the lower layer of the P-type structure, for example, a doping concentration of 5 × 10⁻⁶. 19 atom / cm 3 Up to 1×10 20 atom / cm 3This further optimizes the hole transport capability in the vertical direction. The P-type structure layer provided in the above embodiments can generate a polarization effect with the high-Al-content P-type insertion layer 540 above it. By reducing the lateral resistance through polarization, the horizontal expansion distance of the injected charge carriers is increased, thereby increasing the expansion area of ​​the injected current and achieving the purpose of increasing the effective light-emitting area of ​​the LED device.

[0055] In an optional embodiment, the P-type structure layer may include three stacked sub-structure layers, such as a first P-type layer 510, a second P-type layer 520, and a third P-type layer 530 stacked sequentially. The P-type structure layer provides a low-resistance path for transporting holes from the P-type region to the active layer 400, thereby achieving efficient hole injection. The specific structure and technical solution of each layer of the P-type semiconductor layer 500 provided in this embodiment will be described in detail below.

[0056] Specifically, see Figure 2 and Figure 3 The first P-type layer 510 is located above the active layer 400, and its material is GaN or AlGaN containing a small amount of Al component. When AlGaN material is used, its Al component content is between 5% and 20%. The first P-type layer 510 is the basic structural layer of the hole injection layer.

[0057] Specifically, see Figure 2 and Figure 3 The second P-type layer 520 is located above the first P-type layer 510 and is made of AlGaN. The Al content in the second P-type layer 520 is greater than that in the first P-type layer 510, for example, between 20% and 50%, to facilitate electron reflection back to the active layer, allowing more electrons to recombine with holes within the quantum well, thereby improving luminescence efficiency. As an example, the Al content in the second P-type layer 520 can be 20%, 25%, 30%, or 40%. The Mg doping concentration of the second P-type layer 520 is 1 × 10⁻⁶. 19 atom / cm 3 Up to 1×10 20 atom / cm 3 This can ensure a certain hole concentration while also taking into account crystal quality.

[0058] Specifically, see Figure 2 and Figure 3The third P-type layer 530 is located above the second P-type layer 520 and is made of GaN, without any Al content. The third P-type layer 530 lies between the second P-type layer 520 (with a higher Al content) and the subsequent P-type insertion layer 540, providing a stable GaN surface for the deposition of the P-type insertion layer 540. Furthermore, the high Al content of the P-type insertion layer 540 creates a polarization effect with the contacting third P-type layer 530, reducing lateral resistance and increasing the horizontal expansion distance of injected carriers, thereby increasing the area of ​​injected current expansion and thus increasing the effective light-emitting area of ​​the LED device. Understandably, the three layers of the P-type structure are all constructed using MOCVD technology to control their material and thickness. By adjusting the Al content of each layer in the P-type structure, the hole injection path can be further optimized, reducing current congestion. The P-type structure, along with the subsequent P-type insertion layer 540 and the P-type contact layer 550, synergistically achieve excellent device performance.

[0059] See Figures 1 to 3 A P-type insertion layer 540 is formed on top of the P-type structure layer. The P-type insertion layer 540 is a key functional layer located between the low-Al-content P-type structure layer and its upper P-type contact layer 550. In this embodiment, the Al content of the P-type insertion layer 540 is not less than 50%. As an example, the Al content in the P-type insertion layer 540 is 50%, 60%, 80%, or even 100%. The high-Al-content P-type insertion layer 540 exhibits high resistance in the vertical direction, forcing the injected vertical current to be suppressed in this layer, thereby improving the lateral current spread performance. Furthermore, the high-Al-content P-type insertion layer 540 generates a polarization effect with the underlying low-Al-content or Al-free P-type structure layer, forming a polarized electric field parallel to the interface at the interface. This provides a driving force for the lateral migration of charge carriers. Under the synergistic effect of these two effects, the current spreads laterally from the electrode center region to the peripheral region, which is equivalent to increasing the effective light-emitting area and achieving the effect of improving the light output power. Further, the Al content in the P-type insertion layer 540 is not less than 75%.

[0060] The material of the P-type insertion layer 540 can be AlN or AlGaN. As an example, when the P-type insertion layer 540 is AlGaN, a material layer with a suitable Al content can be obtained by controlling process parameters such as the feedstock flow ratio. As an example, when the P-type insertion layer 540 is AlN, it can be understood that the Al content is 100%.

[0061] In an optional embodiment, the thickness of the P-type insertion layer 540 is between 0.5 nm and 4.0 nm. A suitable thickness ensures the high resistivity of the layer while avoiding reduced current spreading efficiency due to excessive thickness. As an example, the thickness of the P-type insertion layer 540 is 0.5 nm, 1.0 nm, 2.0 nm, or 3.5 nm. Further, the thickness of the P-type insertion layer 540 is between 1.0 nm and 2.0 nm.

[0062] See Figures 1 to 3 A P-type contact layer 550 is formed on top of the P-type insertion layer 540. The P-type contact layer 550 is a Mg-doped superlattice structure with a doping concentration of not less than 1×10⁻⁶. 19 atom / cm 3 Understandably, high doping concentration is a prerequisite for achieving low-resistance ohmic contacts, ensuring that the layer can provide a high density of holes. The superlattice structure also, to some extent, suppresses the diffusion of defects that may be caused by high doping into the active layer. By setting a high-Al composition P-type insertion layer 540 and a high-doped superlattice structure P-type contact layer 550 working synergistically, the high-Al composition P-type insertion layer 540 exhibits high resistance characteristics in the vertical direction, suppressing the vertical concentration of current injection and forcing the current to spread in the horizontal direction, thereby increasing the light-emitting area. The Mg-doped superlattice structure forms a two-dimensional conductive channel through the polarization effect, further reducing the lateral resistance and improving the current spreading efficiency, ultimately achieving an increase in device brightness. Furthermore, its doping concentration is between 1×10⁻⁶. 20 atom / cm 3 Up to 5×10 21 atom / cm 3 P-type doping within this concentration range effectively reduces the driving voltage while avoiding increased photon absorption due to excessive doping. In an optional embodiment, the thickness of the P-type contact layer 550 is between 1 nm and 10 nm, and the thickness can be controlled by adjusting the raw materials and process time. For example, the thickness of the P-type contact layer 550 can be 1 nm, 3 nm, 5 nm, or 8 nm. P-type contact layers 550 with these thicknesses ensure good ohmic contact while avoiding increased resistance due to increased thickness. Further, the thickness of the P-type contact layer 550 is between 2 nm and 4 nm.

[0063] See Figures 1 to 3The superlattice structure of the P-type contact layer 550 consists of a first sublayer 551 and a second sublayer 552 arranged periodically. The Al content of the first sublayer 551 is greater than that of the second sublayer 552, meaning that the bandgap of the first sublayer 551 is greater than that of the second sublayer 552. In this superlattice structure, the first sublayer 551 is closer to the active layer 400 than the second sublayer 552. The superlattice structure with different Al content can form a strong polarization electric field, promoting the migration of charge carriers in the horizontal direction. The second sublayer 552, with its relatively lower Al content, can achieve good ohmic contact with the upper electrode, thereby reducing the contact resistance.

[0064] In some embodiments, the first sublayer 551 comprises AlGaN or AlInGaN, and the second sublayer 552 comprises GaN or InGaN. The superlattice structure comprises 2 to 18 periodically arranged first sublayers 551 and second sublayers 552, and the total thickness does not exceed 20 nm, to avoid excessive thickness leading to increased light absorption, while also taking into account process efficiency.

[0065] As an example, the P-type contact layer 550 is an AlGaN / GaN superlattice structure layer with 2 to 18 periods. The AlGaN layer has a thickness of 0.3 nm to 1.5 nm, the GaN layer has a thickness of 0.3 nm to 3 nm, and the total thickness is between 1 nm and 10 nm. Further, the AlGaN / GaN superlattice structure layer has 3 to 10 periods, and the total thickness is between 2 nm and 4 nm.

[0066] As an example, the P-type contact layer 550 is an AlGaN / InGaN superlattice structure layer with 2 to 18 periods. The AlGaN layer has a thickness of 0.3 nm to 1.5 nm, the InGaN layer has a thickness of 0.3 nm to 3 nm, and the total thickness is between 1 nm and 10 nm. Further, the AlGaN / InGaN superlattice structure layer has 3 to 10 periods, and the total thickness is between 2 nm and 4 nm.

[0067] As an example, the P-type contact layer 550 is an AlInGaN / InGaN superlattice structure layer with 2 to 18 periods. The AlInGaN layer has a thickness of 0.3 nm to 1.5 nm, the InGaN layer has a thickness of 0.3 nm to 3 nm, and the total thickness is between 1 nm and 10 nm. Further, the AlInGaN / InGaN superlattice structure layer has 3 to 10 periods, and the total thickness is between 2 nm and 4 nm.

[0068] In the above embodiment, the ratio of the thickness of the first sublayer 551 to the thickness of the second sublayer 552 is between 1:1 and 1:5 to further optimize the polarization electric field strength and electric field distribution, thereby improving carrier mobility. It is understood that the thinner first sublayer 551 ensures effective carrier passage and avoids excessive thickness leading to increased vertical resistance, while the relatively thicker second sublayer 552 provides sufficient space for the formation of two-dimensional cavitation at the interface.

[0069] In some embodiments, the P-type contact layer 550 provided in this application may also be composed of P-type doped In. x Al y Ga 1-x- y The material is composed of an N-type quaternary alloy, where 0 ≤ x ≤ 0.1, 0 ≤ y ≤ 1, and x + y < 1. The synergistic principle of the InAlGaN contact layer and the underlying high-Al polarization layer is similar to that of the superlattice scheme, and will not be elaborated further here. An effective polarization electric field can still be generated at the interface between InAlGaN and the underlying high-Al composition layer, significantly improving the lateral migration ability of holes, thereby reducing the driving voltage and improving luminous efficiency. Furthermore, the thickness of the InAlGaN P-type contact layer 550 is 1 nm to 10 nm, and its Mg doping concentration ranges from 1 × 10⁻⁶. 20 atom / cm 3 Up to 5×10 21 atom / cm 3 Furthermore, the P-type contact layer 550 is composed of P-type doped In. x Al y Ga 1-x-y The material is composed of N quaternary alloy, where 0≤x≤0.1, 0.05≤y≤0.3, and x+y<1, achieving a good balance between lower driving voltage and higher light extraction efficiency.

[0070] See Figure 1 A transparent conductive layer 600 is formed on top of the P-type semiconductor layer 500 to reduce light absorption, improve light extraction efficiency, and achieve good electrical connection with the external electrode. The transparent conductive layer 600 can be ITO (indium tin oxide), ZnO (zinc oxide), AZO (aluminum-doped zinc oxide), or IZO (indium zinc oxide). As the conductive layer that is in direct contact with the second electrode 820, the thickness and conductivity of the transparent conductive layer 600 have a close influence on the light output brightness of the light-emitting diode. Furthermore, the transparent conductive layer 600 is made of ITO, and its thickness is between 30 Å and 300 Å.

[0071] See also Figure 1An insulating layer 700 is formed above and on the sidewalls of the epitaxial structure and the transparent conductive layer 600. The insulating layer 700 can be one or more insulating material layers containing SiO2, SiN, Al2O3, and ZrO2, such as a single-layer SiO2 insulating material layer or a DBR structure. The insulating layer 700 has a first opening exposing the surface of the N-type semiconductor layer 300 and a second opening exposing the surface of the transparent conductive layer 600. An electrode structure is provided on the insulating layer 700, including a first electrode 810 and a second electrode 820. The first electrode 810 fills the first opening and covers part of the sidewall of the insulating layer 700 for electrical connection with the N-type semiconductor layer 300. The second electrode 820 fills the second opening and covers part of the sidewall of the insulating layer 700 for electrical connection with the P-type semiconductor layer 500. In an optional embodiment, the first electrode 810 and the second electrode 820 may be made of the same material, comprising a single film of a single material or an alloy of two materials selected from Au, Sn, Ni, Pb, Ag, In, Cr, Ge, Si, Ti, W and Pt, or a multilayer structure comprising a combination thereof.

[0072] The above embodiments describe Figure 1 The flip-chip LED structure shown has electrodes located on opposite sides of the light-emitting surface. It is understood that the LED epitaxial structure provided in this application is also applicable to both upright and vertically mounted chips.

[0073] See Figure 4 In the upright structure, the light-emitting diode includes at least a substrate 100 and an epitaxial structure located above the substrate 100. The epitaxial structure includes, in sequence, an N-type semiconductor layer 300, an active layer 400, a P-type semiconductor layer 500, a transparent conductive layer 600, and an electrode structure. The P-type semiconductor layer 500 has the same structure as mentioned in the previous embodiments. The electrode structure includes a first electrode 810 located on the N-side mesa and a second electrode 820 located on the P-side mesa. An insulating layer 700 is also included, covering the surface and sidewalls of the epitaxial structure, the sidewalls of the electrode structure, and part of the upper surface. Optionally, the insulating layer 700 is made of a transparent material. P-contact electrodes and N-contact electrodes can be respectively disposed on the transparent conductive layer 600 on the P-side mesa and on the N-side mesa. To reduce the obstruction of light emission by the electrodes, the P-contact electrodes and N-contact electrodes are typically designed as finger-shaped or ring-shaped shapes with a small area.

[0074] See Figure 5In the vertical structure, the light-emitting diode includes an epitaxial structure, specifically comprising a P-type semiconductor layer 500, an active layer 400, and an N-type semiconductor layer 300 stacked sequentially. Along the direction from the N-type semiconductor layer 300 to the P-type semiconductor layer 500, the P-type semiconductor layer 500 includes a first P-type layer 510, a second P-type layer 520, a third P-type layer 530, a P-type insertion layer 540, and a P-type contact layer 550 stacked sequentially. The P-type semiconductor layer 500 has the same structure as mentioned in the previous embodiments. A first electrode 810 is disposed on one side of the N-type semiconductor layer 300, and a conductive substrate 900 is disposed on one side of the P-type semiconductor layer 500. A second electrode 820 is disposed on the bottom side of the conductive substrate 900; that is, the first electrode 810 and the second electrode 820 are located on different sides of the epitaxial structure.

[0075] The light-emitting diode provided in this embodiment can have a polygonal shape, such as a triangle, hexagon, rectangle, or square. The size of the light-emitting diode can be, for example, a square shape or a rectangular shape of similar size, such as 300μm×100μm, 300μm×120μm, 300μm×150μm, 300μm×200μm, 600μm×200μm, 600μm×150μm, 600μm×120μm, and 1200μm×200μm, but is not particularly limited thereto.

[0076] See Figure 6 This application also provides a light-emitting device 10, which includes an encapsulation substrate 101 and at least one light-emitting element 102 disposed on the surface of the encapsulation substrate 101. The light-emitting element 102 is a light-emitting diode provided in the above embodiments. The encapsulation substrate 101 and the electrode structure of the light-emitting diode are electrically connected. This light-emitting device achieves high brightness and high luminous efficiency output while operating at low voltage, and its overall performance is significantly improved compared to existing products.

[0077] In summary, the light-emitting diode and light-emitting device provided in this application effectively overcome the various shortcomings of the prior art and have high industrial application value.

[0078] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A light-emitting diode, characterized in that, It includes an N-type semiconductor layer, an active layer, and a P-type semiconductor layer stacked sequentially; the P-type semiconductor layer includes: A P-type insertion layer is located above the active layer, wherein the Al composition in the P-type insertion layer is not less than 50%. A P-type contact layer is located above the P-type insertion layer. The P-type contact layer is a P-type doped superlattice structure or an In-type doped superlattice structure. x Al y Ga 1-x-y N, 0≤x≤0.1, 0≤y≤1; wherein the P-type doping concentration is not less than 1×10 19 atom / cm 3 .

2. The light-emitting diode according to claim 1, characterized in that, The P-type insertion layer is an AlN layer or an AlGaN layer.

3. The light-emitting diode according to claim 1, characterized in that, The thickness of the P-type insertion layer is between 0.5 nm and 4.0 nm.

4. The light-emitting diode according to claim 1, characterized in that, The Al component content of the P-type insertion layer is higher than that of the P-type contact layer.

5. The light-emitting diode according to claim 1, characterized in that, The superlattice structure is a structure layer in which the first sublayer and the second sublayer are arranged in a periodic manner, and the Al component content of the first sublayer is greater than that of the second sublayer.

6. The light-emitting diode according to claim 5, characterized in that, The first sublayer is closer to the active layer than the second sublayer.

7. The light-emitting diode according to claim 5, characterized in that, The first sublayer includes AlGaN or AlInGaN, and the second sublayer includes GaN or InGaN.

8. The light-emitting diode according to claim 5, characterized in that, The ratio of the thickness of the first sublayer to the thickness of the second sublayer is between 1:1 and 1:

5.

9. The light-emitting diode according to claim 5, characterized in that, The superlattice structure comprises 2 to 18 periodically arranged structural layers.

10. The light-emitting diode according to claim 1, characterized in that, The superlattice structure is one or more of AlGaN / GaN superlattice, AlGaN / InGaN superlattice, or AlInGaN / InGaN superlattice.

11. The light-emitting diode according to claim 1, characterized in that, The P-type contact layer is Mg-doped, with a doping concentration between 1 × 10⁻⁶. 20 atom / cm 3 Up to 5×10 21 atom / cm 3 .

12. The light-emitting diode according to claim 1, characterized in that, The thickness of the P-type contact layer is between 1 nm and 10 nm.

13. The light-emitting diode according to claim 1, characterized in that, The P-type semiconductor layer further includes a P-type structure layer located between the active layer and the P-type insertion layer, the P-type structure layer comprising a first P-type layer and a second P-type layer stacked sequentially; wherein the Al component content in the second P-type layer is greater than the Al component content in the first P-type layer.

14. The light-emitting diode according to claim 1, characterized in that, The P-type semiconductor layer further includes a P-type structure layer located between the active layer and the P-type insertion layer, the P-type structure layer including a second P-type layer and a third P-type layer stacked sequentially; wherein, the Al component content in the second P-type layer is greater than the Al component content in the third P-type layer.

15. A light-emitting device, characterized in that, The light-emitting device includes: Packaging substrate; At least one light-emitting diode is disposed on the surface of the packaging substrate, and the packaging substrate and the electrode structure of the light-emitting diode are electrically connected; the light-emitting diode is the light-emitting diode according to any one of claims 1 to 14.

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