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 a first semiconductor layer, an active layer and a second semiconductor layer which are sequentially stacked from bottom to top, the active layer comprises Al < m > Ga < 1-m > N barrier layers and Al < n > Ga < 1-n > N potential well layers which are periodically and alternately stacked, and one Al < m > Ga < 1-m > N barrier layer and one Al < n > Ga < 1-n > N potential well layer form a period; in at least one period, the ratio of the thickness of the Al < n > Ga < 1-n > N potential well layer to the thickness of the Al < m > Ga < 1-m > N barrier layer is 1: 3-1: 8. By adjusting the thickness ratio of the Al < n > Ga < 1-n > N potential well layer to the Al < m > Ga < 1-m > N potential barrier layer, the combination efficiency of electrons and holes in a quantum well can be effectively improved, so that the luminous efficiency of the light-emitting diode is improved.

Description

Technical Field

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

[0002] In the field of ultraviolet light emitting diode (LED, Light Emitting Diode) technology, with the advancement of science and technology, its importance in medical disinfection, biological detection, photocuring and other applications has become increasingly prominent. In particular, LEDs in the UVB and UVC bands have become the focus of research due to their high energy characteristics. At present, sapphire is widely used as a substrate material because of its excellent optical and thermal properties, providing a stable growth platform for LED chips. The active area of ​​the ultraviolet LED usually adopts a multiple quantum well structure composed of AlGaN quantum well layer and quantum barrier layer to improve the luminous efficiency and wavelength selectivity.

[0003] However, the lattice constant difference between the sapphire substrate and the active area causes stress problems, affecting LED performance. To alleviate this problem, the industry often grows an AlN buffer layer on the sapphire substrate, which can effectively reduce stress and improve internal quantum efficiency, but the high aluminum component nAl in deep ultraviolet LEDs x Ga 1-x The N-ohm contact layer still has challenges such as many defects and large lattice mismatch, which significantly affects the luminous efficiency of deep ultraviolet LEDs. Summary of the invention

[0004] In view of the defects and shortcomings of light-emitting diodes in the prior art, the present application provides a light-emitting diode and a light-emitting device to improve the light-emitting efficiency of the existing light-emitting diodes.

[0005] One embodiment of the present application provides a light emitting diode, comprising a first semiconductor layer, an active layer, and a second semiconductor layer stacked sequentially from bottom to top;

[0006] The active layer includes periodically alternately stacked Al m Ga 1-m N barrier layer and Al n Ga 1-n N potential well layer, a layer of Al m Ga 1-m N barrier layer and a layer of Al n Ga 1-n The N potential well layer forms a period, 0<m<1, 0<n<1;

[0007] Among them, in at least one of the cycles, the Al n Ga 1-n The thickness of the N potential well layer is related to the Al m Ga 1-mThe ratio of the thickness of the N barrier layer is between 1:3 and 1:8.

[0008] According to another embodiment of the present application, there is provided a light emitting diode, comprising a first semiconductor layer, an active layer, and a second semiconductor layer stacked sequentially from bottom to top;

[0009] The active layer includes periodically alternately stacked Al m Ga 1-m N barrier layer and Al n Ga 1-n N potential well layer, a layer of Al m Ga 1-m N barrier layer and a layer of Al n Ga 1-n The N potential well layer forms a period, 0<m<1, 0<n<1;

[0010] Wherein, in each of the cycles, the Al m Ga 1-m The thickness of the N barrier layer is no greater than 8 nm.

[0011] According to another embodiment of the present application, a light-emitting device is provided, including a circuit board and a plurality of light-emitting units arranged on the circuit board, wherein the light-emitting units include the light-emitting diodes described in the present application.

[0012] As described above, the light emitting diode and the light emitting device of the present application have the following beneficial effects:

[0013] The light emitting diode of the present application is provided by limiting the Al in the active layer n Ga 1-n The thickness of the N potential well layer is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer, or the limit of Al m Ga 1-m The thickness of the N barrier layer effectively improves the effective combination efficiency of electrons and holes in the quantum well, and improves the luminous efficiency of the light-emitting diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Shown is a schematic structural diagram of a light emitting diode in accordance with the first embodiment of the present application.

[0015] Figure 2 Shown is a schematic structural diagram of another light emitting diode according to the first embodiment of the present application.

[0016] Figure 3 Shown is a structural schematic diagram of yet another light emitting diode according to the first embodiment of the present application.

[0017] Figure 4Shown is a schematic structural diagram of a light emitting diode according to the second embodiment of the present application.

[0018] Figure 5 Shown is a schematic structural diagram of a light-emitting device according to the third embodiment of the present application.

[0019] Component number description

[0020] 10, circuit board; 20, light-emitting unit; 100, first semiconductor layer; 200, active layer; 210, Al m Ga 1-m N barrier layer; 220, Al n Ga 1-n N potential well layer; 300, second semiconductor layer; 400, substrate; 500, buffer layer; 600, transition layer; 610, Al x Ga 1- x N layer; 620, Al y Ga 1-y N layer; 700, electron control layer; 800, electron blocking layer. DETAILED DESCRIPTION

[0021] 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.

[0022] In existing deep ultraviolet LEDs, nAl with high aluminum content x Ga 1-x N (x>0.5) ohmic contact layer. First, the AlGaN material with high aluminum content is prone to defects during the growth process, which will capture carriers and reduce the luminous efficiency of the LED. Secondly, the AlN layer and the nAl with high aluminum content x Ga 1-x There is a large difference in lattice constants between N ohmic contact layers, which will lead to lattice mismatch at the interface, further increase the generation of defects and affect the overall performance of the LED.

[0023] Based on the background technology and the above technical defects, the present application provides a light emitting diode, comprising a first semiconductor layer, an active layer and a second semiconductor layer stacked sequentially from bottom to top;

[0024] The active layer includes periodically alternately stacked Al m Ga 1-m N barrier layer and Al n Ga 1-nN potential well layer, a layer of Al m Ga 1-m N barrier layer and a layer of Al n Ga 1-n The N potential well layer forms a period, 0<m<1, 0<n<1;

[0025] Among them, in at least one of the cycles, the Al n Ga 1-n The thickness of the N potential well layer is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer is between 1:3 and 1:8. n Ga 1-n The thickness of the N well layer and the Al m Ga 1-m The ratio of the thickness of the N barrier layer can effectively improve the combination efficiency of electrons and holes in the quantum well, increase the number of photons generated when electrons and holes recombine, improve the brightness of the light-emitting diode, and thus improve the luminous efficiency of the LED.

[0026] In some embodiments, in at least one of the cycles, the Al n Ga 1-n The thickness of the N potential well layer is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer is between 1:4 and 1:7. n Ga 1-n The thickness of the N well layer and the Al m Ga 1-m The ratio of the thickness of the N barrier layer further improves the combination efficiency of electrons and holes in the quantum well, increases the luminous brightness of the light-emitting diode, and further improves the luminous performance of the LED.

[0027] In some embodiments, in each of the cycles, the Al n Ga 1-n The thickness of the N potential well layer is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer is between 1:3 and 1:8. n Ga 1-n The thickness of the N potential well layer is related to the Al m Ga 1-m The consistent ratio of the thickness of the N barrier layer can ensure more consistent performance of the entire active layer and improve the uniformity and reliability of the entire light-emitting diode; the consistent thickness ratio helps to optimize the recombination of electrons and holes in the quantum well, improve the quantum efficiency, and the light-emitting diode has higher luminous efficiency and luminous brightness.

[0028] In some embodiments, in each of the cycles, the Al n Ga 1-n The thickness of the N potential well layer is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer is between 1:4 and 1:7. n Ga 1-n The thickness of the N potential well layer is related to the Al m Ga 1-m The consistent ratio of the thickness of the N barrier layer can further ensure that the performance of the entire active layer is more consistent, and further improve the uniformity and reliability of the entire light-emitting diode.

[0029] In some embodiments, during the one cycle, the Al m Ga 1-m The thickness of the N barrier layer is related to the Al n Ga 1-n The sum of the thickness of the N potential well layer is between 7nm and 10nm. Within this thickness range, the movement of electrons and holes in the active layer can be effectively restricted, the quantum confinement Stark effect can be reduced, the recombination probability of electrons and holes can be enhanced, and the luminous efficiency and brightness can be improved; at the same time, the total thickness of the periodic structure can be controlled to further optimize the recombination probability of electrons and holes, thereby further improving the luminous performance of the LED.

[0030] In some embodiments, during the one cycle, the Al m Ga 1-m The thickness of the N barrier layer is between 6nm and 8nm. m Ga 1-m The thickness of the N barrier layer, on the one hand, ensures the quality of the barrier layer, and on the other hand, is conducive to improving the hole injection efficiency, while effectively improving the combination efficiency of electrons and holes in the active layer in the quantum well, thereby improving the luminous efficiency of the LED.

[0031] In some embodiments, during the one cycle, the Al n Ga 1-n The thickness of the N potential well layer is between 1nm and 2nm. n Ga 1-n The thickness of the N potential well layer, on the one hand, ensures the quality of the potential well layer, and on the other hand, the potential well layer can effectively limit the three-dimensional movement of electrons and holes therein, which helps to increase the recombination probability of electrons and holes in the quantum well and improve the luminous efficiency of the light-emitting diode.

[0032] In some embodiments, m≥0.5, and m>n. m Ga 1-mm≥0.5 in the N barrier layer indicates that the Al content in the barrier layer is relatively high, which increases the band gap width of the barrier layer, improves the blocking effect on electrons, and helps to effectively confine electrons in the quantum well; since m>n, the Al content in the barrier layer is greater than the Al content in the potential well layer, which helps to achieve better overlap of electron and hole wave functions in the quantum well, optimizes the recombination probability of electrons and holes, and improves the luminescence efficiency.

[0033] In some embodiments, along the direction from the first semiconductor layer to the second semiconductor layer, the Al m Ga 1- m The Al component content m in the N barrier layer is constantly distributed. The constant Al component content means that the barrier layer provides a stable electron blocking effect in the entire structure, which helps to maintain the effective confinement of electrons in the quantum well and optimize the recombination process of electrons and holes; the constant distribution of the Al component helps to achieve uniform luminescence characteristics in the entire active layer, reduce the luminescence non-uniformity caused by component fluctuations, and improve the overall luminescence quality of the light-emitting diode; due to the stable electron blocking effect of the barrier layer, the recombination of electrons and holes in the quantum well is more effective, which helps to improve the internal quantum efficiency and overall luminescence efficiency of the light-emitting diode.

[0034] In some embodiments, along the direction from the first semiconductor layer to the second semiconductor layer, the Al m Ga 1- m The Al component content m in the N barrier layer is gradually increasing and gradually distributed. With the gradual increase of the Al component, a gradient electron barrier layer can be formed, which helps to more effectively limit the flow of electrons, reduce the leakage of electrons to the second semiconductor layer, and improve the efficiency of the light-emitting diode; the gradual distribution of the Al component helps to optimize the injection and recombination of electrons and holes, because electrons and holes can meet and recombine more effectively in the quantum well, improving the luminous efficiency; the gradual increase of the Al component helps to reduce the leakage current, because the increase of the barrier layer can prevent the non-radiative recombination of electrons and holes.

[0035] In some embodiments, along the direction from the first semiconductor layer to the second semiconductor layer, the Al n Ga 1-n The Al component content n in the N potential well layer is constantly distributed. The constant Al component content helps to achieve uniform luminescence characteristics in the entire active layer, reduce the luminescence non-uniformity caused by component fluctuations, and improve the overall luminescence quality of the light-emitting diode; it can reduce the leakage of electrons and holes in the quantum well, and improve the internal quantum efficiency and overall luminescence efficiency of the light-emitting diode.

[0036] In some embodiments, along the direction from the first semiconductor layer to the second semiconductor layer, the Aln Ga 1- n The Al component content n in the N barrier layer is distributed in a gradually decreasing gradient. As the Al component content gradually decreases, the energy band of the barrier layer gradually decreases, which helps to more effectively inject electrons and holes into the quantum well and improve the recombination efficiency of carriers. Optimized carrier injection can increase the probability of electron-hole recombination in the quantum well and improve the luminous efficiency of the light-emitting diode; by gradually reducing the Al component content, the lattice mismatch can be reduced, thereby reducing strain and related defects and improving the overall stability of the structure.

[0037] Another embodiment of the present application provides a light emitting diode, comprising a first semiconductor layer, an active layer, and a second semiconductor layer stacked sequentially from bottom to top;

[0038] The active layer includes periodically alternately stacked Al m Ga 1-m N barrier layer and Al n Ga 1-n N potential well layer, a layer of Al m Ga 1-m N barrier layer and a layer of Al n Ga 1-n The N potential well layer forms a period, 0<m<1, 0<n<1;

[0039] Wherein, in each of the cycles, the Al m Ga 1-m The thickness of the N barrier layer is no more than 8nm. A too thick barrier layer will cause electrons and holes to be confined in the barrier layer, causing a large number of electrons and holes to combine in the barrier layer, thereby reducing the probability of electrons and holes being recombined in the quantum well, resulting in reduced luminous efficiency. A thinner barrier layer helps to reduce the quantum confinement Stark effect in the quantum well structure, increase the probability of electrons and holes being recombined in the quantum well, make the recombination of electrons and holes in the quantum well more efficient, and help convert more input electrical energy into light energy, thereby improving the overall luminous efficiency of the light-emitting diode.

[0040] In some embodiments, in each of the cycles, the Al m Ga 1-m The thickness of the N barrier layer is between 6nm and 8nm. By further limiting the thickness of the barrier layer, on the one hand, the quality of the barrier layer is guaranteed, and on the other hand, it is beneficial to improve the hole injection efficiency, and at the same time, it can optimize the recombination probability of electrons and holes in the quantum well, and improve the internal quantum efficiency and overall luminous efficiency of the light-emitting diode.

[0041] In some embodiments, in each of the cycles, the Al n Ga 1-nThe thickness of the N potential well layer is between 1nm and 2nm. By limiting the thickness of the potential well layer, on the one hand, the quality of the potential well layer is guaranteed, and on the other hand, the potential well layer can effectively limit the three-dimensional movement of electrons and holes in it, making the recombination of electrons and holes in the quantum well more effective, which helps to convert more input electrical energy into light energy and improve the overall luminous efficiency of the light-emitting diode.

[0042] In some embodiments, in each of the cycles, the Al n Ga 1-n The thickness of the N potential well layer is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer is between 1:3 and 1:8. n Ga 1- n N potential well layer and Al m Ga 1-m The thickness ratio of the N barrier layer further improves the combination efficiency of electrons and holes in the quantum well and improves the overall luminescence performance of the light-emitting diode.

[0043] In some embodiments, m≥0.5, and m>n. The Al content of the barrier layer is greater than the Al content of the potential well layer, thereby improving the blocking effect on electrons, facilitating the effective confinement of electrons in the quantum well, further promoting the combination of electrons and holes in the quantum well, and improving the overall luminescence performance of the light-emitting diode.

[0044] In some embodiments, a substrate is further included, wherein a transition layer is disposed between the substrate and the first semiconductor layer, and the transition layer comprises Al x Ga 1-x N layer and Al y Ga 1-y N layer, one layer of Al x Ga 1-x N layer and a layer of Al y Ga 1-y The N layers form a period, and 0<x<1, 0<y<1, x≠y. The transition layer helps to gradually adjust the lattice constant to better match the lattice constant difference between the substrate and the first semiconductor layer, reducing stress and potential cracks or defects in the entire structure.

[0045] In some embodiments, a buffer layer is provided between the substrate and the transition layer, and an electron blocking layer is provided between the active layer and the second semiconductor layer. The electron blocking layer can effectively prevent electrons from being injected into the second semiconductor layer, reduce electron leakage, and improve the injection efficiency of electrons in the active layer and the overall luminous efficiency; by optimizing the recombination of electrons and holes, the electron blocking layer helps to improve the internal quantum efficiency of the light-emitting diode and improve the overall luminous efficiency.

[0046] Another embodiment of the present application provides a light emitting device, including a circuit board and a plurality of light emitting units arranged on the circuit board, wherein the light emitting units include the light emitting diodes provided in the present application. The light emitting device includes the light emitting diodes, and thus also has good light emitting efficiency and light emitting brightness.

[0047] It is understandable that the composition and thickness of each layer included in the present application can be analyzed in any suitable manner.

[0048] Embodiment 1

[0049] This embodiment provides a light emitting diode, such as Figure 1 As shown, the light-emitting diode comprises a first semiconductor layer 100, an active layer 200 and a second semiconductor layer 300 stacked in sequence from bottom to top. The active layer 200 is the main region where the light-emitting diode emits light, where electrons and holes recombine and release energy in the form of light; it comprises one or more periodic structures formed by alternately stacking quantum barrier layers and quantum potential well layers, each period consisting of a layer of quantum barrier layer and a layer of quantum potential well layer. In this periodic structure, electrons and holes are confined in quantum potential wells, which increases their wave function overlap, improves the probability of radiation recombination, and is conducive to improving luminous efficiency.

[0050] The active layer 200 of the light emitting diode of this embodiment includes x Al m Ga 1-m N barrier layer 210 and y Al n Ga 1-n N potential well layer 220, a layer of Al m Ga 1-m N barrier layer 210 and a layer of Al n Ga 1-n The N potential well layer 220 forms a period, and 0<m<1, 0<n<1, 1≤x≤20, 1≤y≤20, the values ​​of x and y can be the same or different, and the number of periods can also be selected according to actual needs, for example, it can be 3 to 15 periods, Al m Ga 1-m The N barrier layer 210 has a higher potential than Al n Ga 1-nThe N potential well layer 220 has a larger band gap. The light emitting diode in this embodiment is an ultraviolet light emitting diode, and the materials of the quantum barrier layer and the quantum potential well layer in the active layer 200 are all selected from AlGaN as an example. m Ga 1-m N barrier layer 210 and Al n Ga 1-n The alternating arrangement of the N potential well layers 220 can ensure that the light radiated after the recombination of electrons and holes is ultraviolet light with a wavelength of about 220nm to 410nm, and further, the wavelength is between 240nm and 370nm. n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer 210 is between 1:3 and 1:8. n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer 210 is not specifically limited. Optionally, in at least one period, Al n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer 210 may be, for example, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, etc. Figure 1 As shown, there is only one period of Al in the active layer 200. n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer 210 is between 1:3 and 1:8 (in Figure 1 In the figure, the period is highlighted by a dotted frame), the period can be arranged close to the first semiconductor layer 100, close to the second semiconductor layer 300, or in the middle of the active layer 200, which is not specifically limited in this embodiment. Figure 2 As shown, there are at least two periods but not all periods of Al in the active layer 200. n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer 210 is between 1:3 and 1:8 (in Figure 2In the embodiment, the period with a thickness ratio within the above range is highlighted by a dotted box), the period for defining the thickness ratio of the potential well layer and the barrier layer can be dispersed or centralized, which is not specifically limited in this embodiment; similarly, the period for defining the thickness ratio of the potential well layer and the barrier layer can be close to the first semiconductor layer 100, close to the second semiconductor layer 300, or located in the middle of the active layer 200, which is not specifically limited in this embodiment. In this embodiment, by defining at least one period of Al n Ga 1-n The N potential well layer 220 and Al m Ga 1-m The ratio of the thickness of the N barrier layer 210 increases the combination efficiency of electrons and holes in the quantum well, increases the number of photons generated when electrons and holes recombine, improves the luminance of the light-emitting diode, and further improves the luminous efficiency of the light-emitting diode.

[0051] The first semiconductor layer 100 may be an N-type semiconductor layer that provides electrons through N-type doping. The N-type semiconductor layer may be formed by doping a semiconductor with Si, Ge, Sn, Se, Te, etc., for example.

[0052] The second semiconductor layer 300 may be a P-type semiconductor layer that provides holes through P-type doping. The P-type semiconductor layer may be formed by doping a semiconductor with, for example, Mg, Zn, Ca, Sr, Ba, etc.

[0053] The first semiconductor layer 100 may also be a P-type semiconductor layer, and the second semiconductor layer 300 may also be an N-type semiconductor layer.

[0054] In an optional embodiment, if Figure 1 and Figure 2 As shown, in at least one cycle, Al n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer 210 is between 1:4 and 1:7. Optionally, in at least one period, Al n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer 210 may be, for example, 1:4, 1:5, 1:6, 1:7, etc. By further defining Al n Ga 1-n The N potential well layer 220 and Al m Ga 1-m The ratio of the thickness of the N barrier layer 210 further improves the combination efficiency of electrons and holes in the quantum well, improves the luminance of the light-emitting diode, and further improves the light-emitting performance of the light-emitting diode.

[0055] In an optional embodiment, if Figure 3 As shown, in each cycle, Al n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1- m The ratio of the thickness of the N barrier layer 210 is between 1:3 and 1:8. Optionally, in each period, Al n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer 210 may be, for example, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, etc. By maintaining Al n Ga 1-n N potential well layer 220 and Al m Ga 1-m The consistent ratio of the thickness of the N barrier layer 210 can ensure that the performance of the entire active layer 200 is more consistent, thereby improving the uniformity and reliability of the entire light-emitting diode; the consistent thickness ratio helps to optimize the recombination of electrons and holes in the quantum well, thereby improving the quantum efficiency and the luminous efficiency and brightness of the light-emitting diode; by maintaining the Al in each cycle n Ga 1-n N potential well layer 220 and Al m Ga 1-m The consistent thickness ratio of the N barrier layer 210 can more accurately control the light-emitting wavelength of the light-emitting diode, which is particularly important for applications that require specific spectral output (such as lasers, LED lights of specific colors); maintaining a consistent thickness ratio in each cycle can reduce stress and defects caused by thickness variations, and help improve the long-term stability and life of the light-emitting diode.

[0056] In an optional embodiment, if Figure 3 As shown, in each cycle, Al n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer 210 is between 1:4 and 1:7. Optionally, in each cycle, Al n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer 210 may be, for example, 1:4, 1:5, 1:6, 1:7, etc. By further limiting the Al n Ga 1-n The thickness of the N-well layer 220 is related to the Alm Ga 1-m The consistent ratio of the thickness of the N barrier layer 210 can further ensure that the performance of the entire active layer 200 is more consistent, and further improve the performance consistency and reliability of the entire light-emitting diode; by maintaining a specific thickness ratio in all cycles, the overall performance of the light-emitting diode, such as luminous efficiency and spectral characteristics, can be more systematically optimized to ensure that the performance of the entire light-emitting diode is optimal; when all cycles follow the same design rules, the manufacturing process may be simpler and easier to control, which helps to improve production efficiency and reduce manufacturing variation.

[0057] In an optional embodiment, if Figures 1 to 3 As shown, in one cycle, Al m Ga 1-m The thickness of the N barrier layer 210 is related to the Al n Ga 1-n The total thickness of the N potential well layer 220 is between 7 nm and 10 nm. m Ga 1-m The thickness of the N barrier layer 210 is related to the Al n Ga 1-n The sum of the thicknesses of the N potential well layers 220 may be, for example, 7 nm, 7.5 nm, 8 nm, 8.5 nm, 9 nm, 9.5 nm, 10 nm, etc. Figure 1 As shown, a period of Al in the active layer 200 m Ga 1-m The thickness of the N barrier layer 210 is related to the Al n Ga 1-n The total thickness of the N potential well layer 220 is between 7 nm and 10 nm; the other periods of Al in the active layer 200 m Ga 1-m The thickness of the N barrier layer 210 is related to the Al n Ga 1-n The sum of the thicknesses of the N potential well layers 220 may be less than 7 nm, or greater than 10 nm, which is not specifically limited in this embodiment. Figure 2 As shown, there are at least two periods of Al m Ga 1-m The thickness of the N barrier layer 210 is related to the Al n Ga 1-n The sum of the thickness of the N potential well layer 220 is between 7 nm and 10 nm. Similarly, the Al m Ga 1-m The thickness of the N barrier layer 210 is related to the Al n Ga 1-nThe sum of the thicknesses of the N potential well layers 220 may be less than 7 nm or greater than 10 nm, which is not specifically limited in this embodiment. In this embodiment, one period of the active layer 200 within this thickness range can effectively limit the movement of electrons and holes in the active layer 200, reduce the quantum confinement Stark effect, enhance the recombination probability of electrons and holes, and improve the luminous efficiency and luminous brightness; at the same time, the recombination probability of electrons and holes can be further optimized by controlling the total thickness of the periodic structure, thereby further improving the luminous performance of the light-emitting diode.

[0058] In an optional embodiment, if Figures 1 to 3 As shown, in one cycle, Al m Ga 1-m The thickness of the N barrier layer 210 is between 6 nm and 8 nm. m Ga 1-m The thickness of the N barrier layer 210 can be, for example, 6 nm, 6.5 nm, 7 nm, 7.5 nm, 8 nm, etc. m Ga 1-m The N barrier layer 210 within the above thickness range can ensure the quality of the barrier layer, improve the hole injection efficiency, and effectively limit the movement of electrons and holes in the quantum well, which helps to increase the recombination probability of electrons and holes, thereby improving the luminous efficiency. The appropriate thickness helps to increase the recombination of electrons and holes in the quantum well, thereby improving the luminous efficiency and luminous brightness. m Ga 1-m When the thickness of the N barrier layer 210 is less than 6 nm, the thickness is too thin and the quality will be poor. For example, it may not be able to effectively block the flow of electrons and holes, causing them to leak between different regions of the light-emitting diode; it may not provide sufficient potential energy restriction, resulting in a decrease in the efficiency of electron and hole combination in the quantum well; it may also cause a decrease in luminous efficiency. m Ga 1-m When the thickness of the N barrier layer 210 is greater than 8 nm, the electrons and holes will be confined in the barrier layer, causing the electrons and holes to combine in the barrier layer, reducing the effective combination efficiency of the electrons and holes in the quantum well, thereby causing the luminous efficiency to deteriorate. m Ga 1-m The thickness of the N barrier layer 210 is between 7 nm and 8 nm.

[0059] In an optional embodiment, if Figures 1 to 3 As shown, in one cycle, Al n Ga 1-n The thickness of the N potential well layer 220 is between 1 nm and 2 nm. n Ga 1-nThe thickness of the N potential well layer 220 can be, for example, 1nm, 1.2nm, 1.4nm, 1.6nm, 1.8nm, 2nm, etc. When the thickness of the potential well layer is between 1nm and 2nm, on the one hand, it is conducive to ensuring the quality of the potential well layer, and on the other hand, the potential well layer can effectively limit the three-dimensional movement of electrons and holes therein, which helps to improve the recombination probability of electrons and holes in the quantum well, thereby improving the luminous efficiency of the light-emitting diode. When the thickness of the potential well layer is less than 1nm, the thickness is too thin and the quality will be poor; when the thickness of the potential well layer is greater than 2nm, the thickness will lead to a decrease in the number of holes, and will also reduce the effective combination efficiency of electrons and holes in the quantum well, thereby causing the luminous efficiency to deteriorate.

[0060] In an optional embodiment, m≥0.5, and m>n. Since m≥0.5 in the barrier layer, it means that the Al content in the barrier layer is relatively high, which can increase the band gap width of the barrier layer, thereby improving the blocking effect on electrons and helping to effectively confine electrons in the quantum well; the barrier layer with a high Al content helps to reduce the leakage of electrons, allowing electrons to recombine with holes in the quantum well more effectively, which helps to improve the luminous intensity and luminous efficiency of the light-emitting diode. Furthermore, 0.5≤m≤0.55. Since m>n, that is, the Al content of the barrier layer is higher than that of the potential well layer, it helps to achieve better wave function overlap of electrons and holes in the quantum well, thereby optimizing the recombination probability of electrons and holes and improving the luminous efficiency.

[0061] In an optional embodiment, if Figures 1 to 3 As shown, along the direction from the first semiconductor layer 100 to the second semiconductor layer 300 (ie, from bottom to top), Al m Ga 1-m The Al component content m in the N barrier layer 210 is constantly distributed. The constant Al component content indicates that the barrier layer provides a stable electron blocking effect in the entire structure, which helps to maintain the effective confinement of electrons in the quantum well, thereby optimizing the recombination process of electrons and holes; the constant distribution of the Al component helps to achieve uniform luminescence characteristics in the entire active layer 200, reduce the luminescence non-uniformity caused by component fluctuations, and improve the overall luminescence quality of the light-emitting diode; due to the stable electron blocking effect of the barrier layer, the recombination of electrons and holes in the quantum well is more effective, which helps to improve the internal quantum efficiency and overall luminescence efficiency of the light-emitting diode. In semiconductor materials, component mutations may cause lattice mismatch and stress concentration, while a constant Al component helps to reduce these stresses, thereby reducing the generation of defects and improving the reliability and life of the light-emitting diode. In the manufacturing process, maintaining a constant distribution of the Al component helps to improve product consistency, reduce performance differences between batches, and improve production efficiency and product quality.

[0062] In an optional embodiment, if Figures 1 to 3As shown, along the direction from the first semiconductor layer 100 to the second semiconductor layer 300 (ie, from bottom to top), Al m Ga 1-m The Al component content m in the N barrier layer 210 is gradually increasing and gradually distributed, that is, the Al content of the barrier layer near the second semiconductor layer 300 is higher, which can effectively suppress the electron mobility. With the gradual increase of the Al component, a gradient electron blocking layer can be formed, which helps to more effectively limit the flow of electrons and reduce the leakage of electrons to the P-type region, thereby improving the efficiency of the light-emitting diode; the gradual distribution of the Al component helps to optimize the injection and recombination of electrons and holes, because electrons and holes can meet and recombine more effectively in the quantum well, thereby improving the luminous efficiency. In the active area of ​​the light-emitting diode, the recombination of electrons and holes usually occurs in the quantum well, and the gradual increase of the Al component helps to reduce the leakage current, because the increase of the barrier layer can prevent the non-radiative recombination of electrons and holes.

[0063] In an optional embodiment, if Figures 1 to 3 As shown, along the direction from the first semiconductor layer 100 to the second semiconductor layer 300 (ie, from bottom to top), Al n Ga 1-n The Al component content n in the N potential well layer 220 is constantly distributed. The constant distribution of the Al component helps to improve the recombination process of electrons and holes and improve the luminous efficiency; since the Al component in the potential well is constant, the leakage of electrons and holes in the quantum well can be reduced, thereby improving the internal quantum efficiency and overall luminous efficiency of the light-emitting diode; the constant Al component content helps to achieve uniform luminous characteristics in the entire active layer 200, reduce the luminous non-uniformity caused by component fluctuations, and improve the overall luminous quality of the light-emitting diode.

[0064] In an optional embodiment, if Figures 1 to 3 As shown, along the direction from the first semiconductor layer 100 to the second semiconductor layer 300 (ie, from bottom to top), Al n Ga 1-n The Al component content n in the N potential well layer 220 is gradually reduced in a gradient distribution, that is, the Al component content of the potential well layer close to the first semiconductor layer 100 is higher, which can increase the effective recombination probability of electrons and holes. The gradual reduction of the Al component content helps to form a potential energy gradient, so that electrons and holes are more effectively injected into the quantum well, thereby improving the recombination efficiency and luminescence performance. As the Al component gradually decreases, the strain caused by lattice mismatch can be reduced, because the lattice constant of each layer of material is closer to the substrate or base material, which helps to reduce the formation of dislocations and defects and improve the stability and life of the light-emitting diode.

[0065] Embodiment 2

[0066] This embodiment provides a light emitting diode, such as Figure 4 As shown, the light emitting diode comprises a first semiconductor layer 100, an active layer 200 and a second semiconductor layer 300 stacked sequentially from bottom to top. Similarly, the first semiconductor layer 100 may be an N-type semiconductor layer; the second semiconductor layer 300 may be a P-type semiconductor layer; the active layer 200 comprises Al2O3 stacked periodically and alternately; m Ga 1-m N barrier layer 210 and Al n Ga 1-n N potential well layer 220, a layer of Al m Ga 1-m The N barrier layer 210 and the Al n Ga 1-n The N potential well layer 220 forms a period, 0<m<1, 0<n<1; in each period, Al m Ga 1-m The thickness of the N barrier layer 210 is not greater than 8 nm. A too thick barrier layer will cause electrons and holes to be confined in the barrier layer, causing a large number of electrons and holes to combine in the barrier layer, thereby reducing the recombination probability of electrons and holes in the quantum well, resulting in reduced luminous efficiency. m Ga 1-m The thickness of the N barrier layer 210 helps to reduce the quantum confinement Stark effect in the quantum well structure, increase the recombination probability of electrons and holes in the quantum well, make the recombination of electrons and holes in the quantum well more efficient, and at the same time help to convert more input electrical energy into light energy, thereby improving the overall luminous efficiency of the light-emitting diode.

[0067] In an optional embodiment, in each cycle, Al m Ga 1-m The thickness of the N barrier layer 210 is between 6 nm and 8 nm. m Ga 1-m The thickness of the N barrier layer 210 can be, for example, 6 nm, 6.5 nm, 7 nm, 7.5 nm, 8 nm, etc. By further limiting the thickness of the barrier layer, on the one hand, the quality of the barrier layer is guaranteed, and on the other hand, it is beneficial to improve the hole injection efficiency, and at the same time, it can optimize the recombination probability of electrons and holes in the quantum well, thereby improving the internal quantum efficiency and overall luminous efficiency of the light-emitting diode. m Ga 1-m The thickness of the N barrier layer 210 is between 7 nm and 8 nm.

[0068] In an optional embodiment, in each cycle, Al n Ga 1-n The thickness of the N potential well layer 220 is between 1 nm and 2 nm.n Ga 1-n The thickness of the N potential well layer 220 can be, for example, 1 nm, 1.2 nm, 1.4 nm, 1.6 nm, 1.8 nm, 2 nm, etc. Within the above specific thickness range, on the one hand, the quality of the potential well layer is guaranteed, and on the other hand, the quantum potential well layer can effectively limit the three-dimensional movement of electrons and holes therein, making the recombination of electrons and holes in the quantum well more effective, which helps to convert more input electrical energy into light energy and improve the overall luminous efficiency of the light-emitting diode.

[0069] In an optional embodiment, in each cycle, Al n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer 210 is between 1:3 and 1:8. Optionally, in each period, Al n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1-m The thickness ratio of the N barrier layer 210 is 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, etc. By further defining the Al n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1-m The thickness ratio of the N barrier layer 210 further improves the efficiency of electron and hole combination in the quantum well, and improves the overall light-emitting performance of the light-emitting diode. n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer 210 is between 1:4 and 1:7. Optionally, in each period, Al n Ga 1-n The thickness of the N-well layer 220 is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer 210 may be, for example, 1:4, 1:5, 1:6, 1:7, etc.

[0070] In an optional embodiment, m≥0.5, and m>n. m Ga 1-mm≥0.5 in the N barrier layer 210 indicates that the Al content in the barrier layer is relatively high, which increases the band gap width of the barrier layer, improves the blocking effect on electrons, helps to effectively confine electrons in the quantum well, further improves the combination of electrons and holes in the quantum well, and improves the overall luminescence performance of the light-emitting diode. Since m>n, the Al content of the barrier layer is greater than the Al content in the potential well layer, which helps to achieve better overlap of electron and hole wave functions in the quantum well, optimizes the recombination efficiency of carriers, and improves the luminescence efficiency. Further, 0.5≤m≤0.55. The Al component within the above range can enhance the recombination of electrons and holes in the quantum well, because the band structure of the barrier layer helps to balance the injection of electrons and holes and improve the combination efficiency.

[0071] In an optional embodiment, if Figure 4 As shown, the light emitting diode further includes a substrate 400. The substrate 400 provides mechanical support for the light emitting diode, ensures the stability of the device during processing and use, and helps to conduct heat from the light emitting diode to the external environment, which is crucial for heat dissipation. The material of the substrate 400 can be selected from one or more of sapphire, SiC, GaAs, GaN, AlN, GaP, Si, ZnO and MnO. The substrate 400 provided in this embodiment adopts a sapphire substrate.

[0072] In an optional embodiment, if Figure 4 As shown, the light emitting diode further includes a buffer layer 500. The buffer layer 500 helps to alleviate the lattice mismatch between the substrate 400 and the first semiconductor layer 100, reduce dislocations and lattice defects, and improve the photoelectric performance of the light emitting diode. The material of the buffer layer 500 can be selected from, for example, AlN, GaN, SiC, etc., and the material of the buffer layer 500 in this embodiment is AlN.

[0073] In an optional embodiment, if Figure 4 As shown, the light emitting diode further includes a transition layer 600, which is disposed between the buffer layer 500 and the first semiconductor layer 100. The transition layer 600 includes Al x Ga 1-x N layer 610 and Al y Ga 1-y N layer 620, one layer of Al x Ga 1-x N layer 610 and a layer of Al y Ga 1-y The N layer 620 forms a period, and 0<x<1, 0<y<1, x≠y. The transition layer 600 is formed by periodically stacking Al x Ga 1-x N layer 610 and Al y Ga 1-yThe N layer 620 helps to relieve stress caused by the difference in lattice constants, can reduce the lattice mismatch between the substrate 400 and the active layer 200, reduce dislocations and other defects, and improve the overall quality of the light emitting diode.

[0074] In an optional embodiment, if Figure 4 As shown, the light emitting diode further includes an electron blocking layer 800, which is disposed between the active layer 200 and the second semiconductor layer 300. The main function of the electron blocking layer 800 is to block electrons and prevent the electrons from excessively diffusing into the second semiconductor layer 300, thereby improving the efficiency and performance of the light emitting diode. The material of the electron blocking layer 800 is selected from P-type AlGaN, P-type GaN, or P-type InGaN. The material of the electron blocking layer 800 of this embodiment is selected from P-type AlGaN. When the Al component is high, the band gap width can be increased, and electrons can be blocked more effectively.

[0075] In an optional embodiment, if Figure 4 As shown, the light emitting diode further includes an electronic control layer 700, which is disposed between the first semiconductor layer 100 and the active layer 200. The electronic control layer 700 may also be referred to as an electron transport layer or an N-type semiconductor layer, and its main function is to control the flow of electrons to the active layer 200 to optimize the injection and recombination process of electrons and holes. The material of the electronic control layer 700 may be selected from, for example, N-type GaN, N-type AlGaN, or N-type InGaN. Since the light emitting diode of this embodiment is an ultraviolet light emitting diode, the material of the electronic control layer 700 is selected from N-type AlGaN, and Si-doped N-type AlGaN may be used to adapt to a higher band gap.

[0076] Embodiment 3

[0077] This embodiment provides a light emitting device, such as Figure 5 As shown, it includes a circuit board 10 and a plurality of light-emitting units 20 arranged on the circuit board 10, and the light-emitting units 20 include the light-emitting diodes provided in the first embodiment or the second embodiment. The light-emitting diodes in the first embodiment or the second embodiment are defined by Al n Ga 1-n The N potential well layer 220 and Al m Ga 1-m The thickness ratio of the N barrier layer 210 or the Al n Ga 1-n The thickness of the N potential well layer 220 effectively improves the effective combination efficiency of electrons and holes in the quantum well, and improves the luminous efficiency of the light emitting diode. The light emitting unit 20 of this embodiment uses the light emitting diode provided by the first or second embodiment, which is conducive to improving the luminous efficiency of the light emitting device.

[0078] 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, characterized in that: It includes a first semiconductor layer, an active layer and a second semiconductor layer stacked sequentially from bottom to top; The active layer includes periodically alternately stacked Al m Ga 1-m N barrier layer and Al n Ga 1-n N potential well layer, a layer of Al m Ga 1-m N barrier layer and a layer of Al n Ga 1-n The N potential well layer forms a period, 0<m<1, 0<n<1; Among them, in at least one of the cycles, the Al n Ga 1-n The thickness of the N potential well layer is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer is between 1:3 and 1:

8.

2. The light emitting diode according to claim 1, characterized in that: In at least one of the cycles, the Al n Ga 1-n The thickness of the N potential well layer is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer is between 1:4 and 1:

7.

3. The light emitting diode according to claim 1, characterized in that: In each of the cycles, the Al n Ga 1-n The thickness of the N potential well layer is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer is between 1:3 and 1:

8.

4. The light emitting diode according to claim 3, characterized in that: In each of the cycles, the Al n Ga 1-n The thickness of the N potential well layer is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer is between 1:4 and 1:

7.

5. The light emitting diode according to claim 1, characterized in that: In the one cycle, the Al m Ga 1-m The thickness of the N barrier layer is related to the Al n Ga 1-n The sum of the thicknesses of the N potential well layers is between 7 nm and 10 nm.

6. The light emitting diode according to claim 1, characterized in that: In the one cycle, the Al m Ga 1-m The thickness of the N barrier layer is between 6 nm and 8 nm.

7. The light emitting diode according to claim 1 or 6, characterized in that: In the one cycle, the Al n Ga 1- n The thickness of the N potential well layer is between 1 nm and 2 nm.

8. The light emitting diode according to claim 1, characterized in that: m≥0.5, and m>n.

9. The light emitting diode according to claim 1 or 8, characterized in that: Along the direction from the first semiconductor layer to the second semiconductor layer, the Al m Ga 1-m The Al component content m in the N barrier layer presents a constant distribution.

10. The light emitting diode according to claim 1 or 8, characterized in that: Along the direction from the first semiconductor layer to the second semiconductor layer, the Al m Ga 1-m The Al component content m in the N barrier layer shows a gradual increasing gradient distribution.

11. The light emitting diode according to claim 1 or 8, characterized in that: From the first semiconductor layer to the second The direction of the semiconductor layer, the Al n Ga 1-n The Al component content n in the N potential well layer is constantly distributed.

12. The light emitting diode according to claim 1 or 8, characterized in that: From the first semiconductor layer to the second The direction of the semiconductor layer, the Al n Ga 1-n The Al component content n in the N potential well layer shows a gradually decreasing gradient distribution.

13. A light emitting diode, characterized in that: The invention comprises a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence from bottom to top. Semiconductor layer; The active layer includes periodically alternately stacked Al m Ga 1-m N barrier layer and Al n Ga 1-n N potential well layer, a layer of Al m Ga 1-m N barrier layer and a layer of Al n Ga 1-n The N potential well layer forms a period, 0<m<1, 0<n<1; Wherein, in each of the cycles, the Al m Ga 1-m The thickness of the N barrier layer is no greater than 8 nm.

14. The light emitting diode according to claim 13, characterized in that: In each of the cycles, the Al m Ga 1- m The thickness of the N barrier layer is between 6 nm and 8 nm.

15. The light emitting diode according to claim 13 or 14, characterized in that: In each of the cycles, the Al n Ga 1-n The thickness of the N potential well layer is between 1 nm and 2 nm.

16. The light emitting diode according to claim 13 or 14, characterized in that: In each of the cycles, the Al n Ga 1-n The thickness of the N potential well layer is related to the Al m Ga 1-m The ratio of the thickness of the N barrier layer is between 1:3 and 1:

8.

17. The light emitting diode according to claim 13 or 14, characterized in that: m≥0.5, and m>n.

18. The light emitting diode according to claim 1 or 13, characterized in that: The invention also includes a substrate, wherein a transition layer is disposed between the substrate and the first semiconductor layer, and the transition layer includes Al2O3 periodically and alternately stacked x Ga 1-x N layers and Al y Ga 1-y N layer, one layer of Al x Ga 1-x N layer and a layer of Al y Ga 1-y N layers form a period, and 0<x<1, 0<y<1, x≠y.

19. The light emitting diode according to claim 1 or 13, characterized in that: A buffer layer is arranged between the substrate and the transition layer, and an electron blocking layer is arranged between the active layer and the second semiconductor layer.

20. A light emitting device, characterized in that: It comprises a circuit board and a plurality of light-emitting units arranged on the circuit board, wherein the light-emitting units comprise the light-emitting diodes according to any one of claims 1 to 19.

Images