A deep ultraviolet light emitting diode

Abstract

This invention provides a deep ultraviolet light-emitting diode, comprising, from bottom to top, a substrate, an intrinsic layer, an N-type contact layer, an N-type Bragg reflector layer, a first waveguide layer, a quantum well active layer, a second waveguide layer, a P-type Bragg reflector layer, and a P-type contact layer, wherein the N-type Bragg reflector layer is Al. x1 Ga y1 In 1‑x1‑y1 N-layer and Al x2 Ga y2 In 1‑x2‑y2 The periodic structure consists of N alternating layers, with the P-type Bragg reflector being Al. x3 Ga y3 In 1‑x3‑y3 N-layer and Al x4 Ga y4 In 1‑x4‑y4 The structure is a periodic structure composed of N alternating layers, with the first waveguide layer being N-type doped Al. k1 In j1 Ga 1‑k1‑j1 The material is N, and the Al content in the first waveguide layer decreases linearly from the N-type Bragg reflector layer to the quantum well active layer. The second waveguide layer is P-type doped Al. k2 In j2 Ga 1‑k2‑j2 The invention uses N material, and the Al component content in the second waveguide layer increases linearly from the quantum well active layer to the P-type Bragg reflector layer; this invention can effectively improve the light extraction efficiency of deep ultraviolet light-emitting diodes.

Description

Technical Field

[0001] This invention relates to the field of semiconductor optoelectronics, and more particularly to a deep ultraviolet light-emitting diode. Background Technology

[0002] In the ultraviolet spectrum, light with wavelengths between 200 and 350 nanometers is called deep ultraviolet light. Deep ultraviolet light-emitting diodes (LEDs) have significant application value in fields such as lighting, sterilization, medical treatment, printing, biochemical detection, high-density information storage, and secure communication due to their advantages of high efficiency, environmental friendliness, energy saving, and reliability—advantages that ordinary ultraviolet LEDs cannot match.

[0003] Currently, all deep ultraviolet (DUV) light-emitting diodes (LEDs) on the market, whether using a flip-chip or vertical structure, extract light from the sapphire side on the back. Due to the significant difference in refractive index between sapphire and air, less than 4% of the light is emitted within the emission angle. Furthermore, in AlGaN-based DUVs, the ionization energies of donor and acceptor impurities in AlGaN material increase with increasing Al content, reducing carrier concentration. In particular, the hole concentration in p-type AlGaN material with high Al content is extremely low. Simultaneously, the increase in compensation and scattering centers reduces its mobility, resulting in extremely low conductivity of p-type AlGaN material, making it impossible to form a good ohmic contact with the metal electrode. Therefore, p-type GaN must be used as the top electrode contact layer. However, because p-type GaN material strongly absorbs ultraviolet light, the efficiency of light emission from the front of the DUV is very low, leading to a low light output efficiency.

[0004] Therefore, there is an urgent need for a deep ultraviolet light-emitting diode to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a deep ultraviolet light-emitting diode (DUV) to improve the technical problem of low light output efficiency of existing deep ultraviolet LEDs.

[0006] To solve the above-mentioned technical problems, the present invention provides a deep ultraviolet light-emitting diode, comprising a substrate, an intrinsic layer, an N-type contact layer, an N-type Bragg reflector layer, a first waveguide layer, a quantum well active layer, a second waveguide layer, a P-type Bragg reflector layer, and a P-type contact layer stacked from bottom to top;

[0007] Among them, the N-type Bragg reflector is Al x1 Ga y1 In 1-x1-y1 N-layer and Al x2 Ga y2 In 1-x2-y2A periodic structure composed of N alternating layers, where x1, x2, y1, and y2 satisfy the following relationships: 0 < x1 ≤ 1, 0 ≤ y1 ≤ 1, 0 ≤ x1 + y1 ≤ 1, 0 < x2 ≤ 1, 0 ≤ y2 ≤ 1, 0 ≤ x2 + y2 ≤ 1; the P-type Bragg reflector is Al. x3 Ga y3 In 1-x3-y3 N-layer and Al x4 Ga y4 In 1-x4-y4 The periodic structure consisting of N alternating layers, x3, x4, y3 and y4 satisfy the following relationship: 0 < x3 ≤ 1, 0 ≤ y3 ≤ 1, 0 ≤ x3 + y3 ≤ 1, 0 < x4 ≤ 1, 0 ≤ y4 ≤ 1, 0 ≤ x4 + y4 ≤ 1;

[0008] The first waveguide layer is N-type doped Al. k1 In j1 Ga 1-k1-j1 The material is N, and the Al content in the first waveguide layer decreases linearly from the N-type Bragg reflector layer to the quantum well active layer, with k1 and j1 satisfying the following relationships: 0≤k1≤1, 0≤j1≤1, 0≤k1+j1≤1; the second waveguide layer is P-type doped Al. k2 In j2 Ga 1-k2-j2 The material is N, and the Al content in the second waveguide layer increases linearly from the quantum well active layer to the P-type Bragg reflector layer. k2 and j2 satisfy the following relationship: 0≤k2≤1, 0≤j2≤1, 0≤k2+j2≤1.

[0009] In the deep ultraviolet light-emitting diode provided in the embodiments of the present invention, Al x1 Ga y1 In 1-x1-y1 The thickness of layer N is t1, Al x1 Ga y1 In 1-x1-y1 The average refractive index of the N layer is n1; Al x2 Ga y2 In 1-x2-y2 The thickness of layer N is t2, Al x2 Ga y2 In 1-x2-y2 The average refractive index of layer N is n2;

[0010] Among them, t1, t2, n1 and n2 satisfy the following relationship: t1*n1=t2*n2=λ / 4, where λ is the center wavelength of the emitted light in the active layer of the quantum well.

[0011] In the deep ultraviolet light-emitting diode provided in the embodiments of the present invention, Al x1 Ga y1 In1-x1-y1 The band gap of layer N is E1, Al x2 Ga y2 In 1-x2-y2 The band gap of layer N is E2;

[0012] Among them, E1 and E2 satisfy the following relationship: 1240 / E1<λ, 1240 / E2<λ.

[0013] In the deep ultraviolet light-emitting diode provided in the embodiments of the present invention, Al x3 Ga y3 In 1-x3-y3 The thickness of layer N is t3, Al x3 Ga y3 In 1-x3-y3 The average refractive index of the N layer is n3; Al x4 Ga y4 In 1-x4-y4 The thickness of layer N is t4, Al x4 Ga y4 In 1-x4-y4 The average refractive index of the N layer is n4;

[0014] Among them, t3, t4, n3 and n4 satisfy the following relationship: t3*n3=t4*n4=λ / 4.

[0015] In the deep ultraviolet light-emitting diode provided in the embodiments of the present invention, Al x3 Ga y3 In 1-x3-y3 N layer and Al x4 Ga y4 In 1-x4-y4 The band gap of at least one of the N layers is greater than the photon energy of the emitted light in the active layer of the quantum well.

[0016] In the deep ultraviolet light-emitting diode provided in the embodiments of the present invention, the quantum well active layer is a periodic structure composed of alternating layers of barrier layer and potential well layer, and the number of periods of the quantum well active layer ranges from 2 to 8.

[0017] The difference between the band gap of the barrier layer and the photon energy of the emitted light in the active layer of the quantum well is greater than 0.12 eV.

[0018] In the deep ultraviolet light-emitting diode provided in the embodiments of the present invention, the band gap of the first waveguide layer decreases linearly in the direction from the N-type Bragg reflector layer to the quantum well active layer, and the band gap of the surface of the first waveguide layer in contact with the quantum well active layer is equal to the band gap of the barrier layer.

[0019] In the deep ultraviolet light-emitting diode provided in the embodiments of the present invention, the band gap of the second waveguide layer increases linearly in the direction from the quantum well active layer to the P-type Bragg reflector layer.

[0020] wherein the band gap of the surface of the second waveguide layer in contact with the quantum well active layer is equal to the band gap of the barrier layer, and the band gap of the surface of the second waveguide layer in contact with the P-type Bragg reflector is smaller than the band gap of the surface of the first waveguide layer in contact with the N-type Bragg reflector.

[0021] In the deep ultraviolet light-emitting diode provided by the embodiment of the present invention, the number of periods of the N-type Bragg reflector is m, and the number of periods of the P-type Bragg reflector is n;

[0022] wherein the value range of m is 5<m<40; the value range of n is 3<n<10.

[0023] In the deep ultraviolet light-emitting diode provided by the embodiment of the present invention, the thickness of the first waveguide layer ranges from 50 to 1000 nm, and the thickness of the second waveguide layer ranges from 30 to 500 nm.

[0024] The beneficial effect of the present invention is that, different from the situation of the prior art, the present invention provides a deep ultraviolet light-emitting diode, which comprises a substrate, an intrinsic layer, an N-type contact layer, an N-type Bragg reflector, a first waveguide layer, a quantum well active layer, a second waveguide layer, a P-type Bragg reflector and a P-type contact layer stacked in sequence from bottom to top, wherein the N-type Bragg reflector is formed by Al x1 Ga y1 In 1-x1-y1 N layer and Al x2 Ga y2 In 1-x2-y2 N layer alternately stacked to form a periodic structure, and the P-type Bragg reflector is formed by Al x3 Ga y3 In 1-x3-y3 N layer and Al x4 Ga y4 In 1-x4-y4 N layer alternately stacked to form a periodic structure, the first waveguide layer is an N-type doped Al k1 In j1 Ga 1-k1-j1 N material, and the Al component content in the first waveguide layer decreases linearly in the direction from the N-type Bragg reflector to the quantum well active layer, and the second waveguide layer is a P-type doped Al k2 In j2 Ga 1-k2-j2The invention uses N-type material, and the Al content in the second waveguide layer increases linearly from the quantum well active layer to the P-type Bragg reflector layer. By using an N-type Bragg reflector layer to reflect the first emitted light from the quantum well active layer towards the substrate into the first waveguide layer, and by using a P-type Bragg reflector layer to reflect the second emitted light from the quantum well active layer towards the P-type contact layer into the second waveguide layer, the emitted light from the quantum well active layer is emitted from the side, thereby improving the light extraction efficiency of the deep ultraviolet (DUV) LED and ultimately improving its luminous efficiency. Simultaneously, the Al-component-gradient second waveguide layer acts as an electron blocking layer to confine electron carriers to the quantum well active layer, and the Al-component-gradient first waveguide layer acts as a hole blocking layer to confine hole carriers to the quantum well active layer, thereby improving the recombination efficiency of electrons and holes in the quantum well active layer and ultimately improving the luminous efficiency of the DUV LED. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the deep ultraviolet light-emitting diode provided in an embodiment of the present invention;

[0026] Figure 2 This is a process flow diagram of the epitaxial growth method for deep ultraviolet light-emitting diodes provided in an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the energy band structure of a deep ultraviolet light-emitting diode near the active layer of a quantum well, provided in an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram of the optical path for forward light emission in a deep ultraviolet light-emitting diode provided in an embodiment of the present invention. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0030] Please see Figures 1 to 4 The present invention provides a deep ultraviolet light-emitting diode, comprising, from bottom to top, a substrate, an intrinsic layer, an N-type contact layer, an N-type Bragg reflector layer, a first waveguide layer, a quantum well active layer, a second waveguide layer, a P-type Bragg reflector layer, and a P-type contact layer;

[0031] Among them, the N-type Bragg reflector is Al x1 Ga y1 In 1-x1-y1N-layer and Al x2 Ga y2 In 1-x2-y2 The periodic structure consists of N alternating layers, with the P-type Bragg reflector being Al. x3 Ga y3 In 1-x3-y3 N-layer and Al x4 Ga y4 In 1-x4-y4 The structure is a periodic structure composed of N alternating layers, with the first waveguide layer being N-type doped Al. k1 In j1 Ga 1-k1-j1 The material is N, and the Al content in the first waveguide layer decreases linearly from the N-type Bragg reflector layer to the quantum well active layer. The second waveguide layer is P-type doped Al. k2 In j2 Ga 1-k2-j2 The material is N, and the Al content in the second waveguide layer increases linearly from the quantum well active layer to the P-type Bragg reflector layer.

[0032] This invention uses an N-type Bragg reflector to reflect the first emitted light from the quantum well active layer towards the substrate into a first waveguide layer, and uses a P-type Bragg reflector to reflect the second emitted light from the quantum well active layer towards the P-type contact layer into a second waveguide layer. This ensures that all emitted light from the quantum well active layer exits from the side, thereby improving the light extraction efficiency of the deep ultraviolet (DUV) LED and ultimately its luminous efficiency. Simultaneously, the first waveguide layer with a graded Al composition acts as an electron blocking layer to confine electron carriers to the quantum well active layer, and the second waveguide layer with a graded Al composition acts as a hole blocking layer to confine hole carriers to the quantum well active layer. This further improves the recombination efficiency of electrons and holes in the quantum well active layer, ultimately enhancing the luminous efficiency of the DUV LED.

[0033] The technical solution of this application will now be described in conjunction with specific embodiments.

[0034] Please see Figure 1 as well as Figure 3 , Figure 1 A schematic diagram of the cross-sectional structure of the deep ultraviolet light-emitting diode 100 provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the energy band of the deep ultraviolet light-emitting diode 100 provided in an embodiment of the present invention near the quantum well active layer 16; specifically, the deep ultraviolet light-emitting diode 100 includes a substrate 11, an intrinsic layer 12, an N-type contact layer 13, an N-type Bragg reflector layer 14, a first waveguide layer 15, a quantum well active layer 16, a second waveguide layer 17, a P-type Bragg reflector layer 18, and a P-type contact layer 19 stacked from bottom to top;

[0035] Among them, the N-type Bragg reflector 14 is Al x1 Ga y1 In 1-x1-y1 N-layer and Al x2 Ga y2 In 1-x2-y2 The periodic structure consists of N alternating layers, with the P-type Bragg reflector layer being Al18. x3 Ga y3 In 1-x3-y3 N-layer and Al x4 Ga y4 In 1-x4-y4 The structure is a periodic structure composed of N alternating layers, with the first waveguide layer 15 being N-type doped Al. k1 In j1 Ga 1-k1-j1 The material is N, and the Al content in the first waveguide layer 15 decreases linearly from the N-type Bragg reflector layer 14 to the quantum well active layer 16. The second waveguide layer 17 is P-type doped Al. k2 In j2 Ga 1-k2-j2 The material is N, and the Al component content in the second waveguide layer 17 increases linearly in the direction from the quantum well active layer 16 to the P-type Bragg reflector layer 18.

[0036] In this embodiment of the invention, the substrate 11 is a nano-patterned sapphire material. Sapphire material has many advantages: firstly, the production technology of sapphire material is mature and the device quality is good; secondly, sapphire has excellent stability and can be used in high-temperature growth processes; finally, sapphire has high mechanical strength and is easy to handle and clean. Therefore, most processes generally use sapphire as the substrate 11.

[0037] In this embodiment of the invention, the intrinsic layer 12 includes a low-temperature buffer layer disposed on the substrate 11 and a template layer disposed on the low-temperature buffer layer; wherein, the material of the low-temperature buffer layer is aluminum nitride, the growth temperature ranges from 400 degrees Celsius to 800 degrees Celsius, and the thickness ranges from 10 nm to 50 nm; the template layer is aluminum nitride, the growth temperature ranges from 1100 degrees Celsius to 1300 degrees Celsius, and the thickness ranges from 500 nm to 4000 nm.

[0038] In this embodiment of the invention, the material of the N-type contact layer 13 is silicon-doped aluminum gallium nitride material, and the dopant is SiH4; wherein, the aluminum content in the N-type contact layer 13 is between 20% and 90%, the thickness of the N-type contact layer 13 is between 500 nm and 4000 nm, and the growth temperature of the N-type contact layer 13 is between 1000 degrees Celsius and 1250 degrees Celsius.

[0039] In this embodiment of the invention, the N-type Bragg reflector layer 14 includes a multi-layer stacked structure, each of which includes Al layers stacked from bottom to top. x1 Ga y1 In 1-x1-y1 N layer and Al x2 Ga y2 In 1-x2-y2 N layers;

[0040] Among them, x1 and y1 satisfy the following relationship: 0 < x1 ≤ 1, 0 ≤ y1 ≤ 1, 0 ≤ x1 + y1 ≤ 1; x2 and y2 satisfy the following relationship: 0 < x2 ≤ 1, 0 ≤ y2 ≤ 1, 0 ≤ x2 + y2 ≤ 1.

[0041] Specifically, Al x1 Ga y1 In 1-x1-y1 The thickness of layer N is t1, Al x1 Ga y1 In 1-x1-y1 The average refractive index of the N layer is n1; Al x2 Ga y2 In 1-x2-y2 The thickness of layer N is t2, Al x2 Ga y2 In 1-x2-y2 The average refractive index of layer N is n2;

[0042] Among them, t1, t2, n1 and n2 satisfy the following relationship: t1*n1=t2*n2=λ / 4, where λ is the center wavelength of the emitted light in the active layer 16 of the quantum well.

[0043] Furthermore, the above design makes each sublayer in the superlattice periodic structure of the N-type Bragg reflector 14 a distributed Bragg mirror. On the one hand, it can further reflect more than 99% of the light that conforms to the center wavelength of the light emitted from the quantum well active layer 16 and suppress stray light that does not conform to the center wavelength of the light emitted from the quantum well active layer 16. On the other hand, it can further effectively improve the brightness of the deep ultraviolet light emitting diode 100.

[0044] Specifically, the dopant in the N-type Bragg reflector layer 14 is a silicon-containing N-type dopant, which is beneficial for providing a large number of electron carriers and acting as an electron injection layer.

[0045] Specifically, the number of stacked layers (m) in the N-type Bragg reflector layer 14 ranges from 5 to 40. When the number of stacked layers in the N-type Bragg reflector layer 14 is less than 5, the effect of the N-type Bragg reflector layer 14 in reflecting the emitted light emitted by the quantum well active layer 16 along the direction of the substrate 11 is not very significant; when the number of stacked layers in the N-type Bragg reflector layer 14 is greater than 40, it leads to a decrease in the electron input capability of the deep ultraviolet light-emitting diode 100.

[0046] Specifically, Al x1 Ga y1 In 1-x1-y1 The band gap of layer N is E1, Al x2 Ga y2 In 1-x2-y2 The band gap of the N-layer is E2; where E1 and E2 satisfy the following relationship: 1240 / E1 < λ, 1240 / E2 < λ (the units of E1 and E2 are electron volts). This setting is to ensure that the N-type Bragg reflector layer 14 is transparent to the wavelength of the emitted light from the quantum well active layer 16; that is, to ensure that the photons of the emitted light from the quantum well active layer 16 along the direction of the substrate 11 are not absorbed by the N-type Bragg reflector layer 14, so that the emitted light can be reflected back.

[0047] In this embodiment of the invention, the first waveguide layer 15 is N-type doped Al. k1 In j1 Ga 1-k1-j1 The material is N, and the Al content in the first waveguide layer 15 decreases linearly in the direction from the N-type Bragg reflector layer 14 to the quantum well active layer 16. k1 and j1 satisfy the following relationship: 0≤k1≤1, 0≤j1≤1, 0≤k1+j1≤1.

[0048] Specifically, the thickness of the first waveguide layer 15 ranges from 50 to 1000 nm; the band gap of the first waveguide layer 15 decreases linearly in the direction from the N-type Bragg reflector layer 14 to the quantum well active layer 16, and the band gap of the surface of the first waveguide layer 15 in contact with the quantum well active layer 16 is equal to the band gap of the barrier layer 161.

[0049] The band gap of the first waveguide layer 15 decreases linearly in the direction from the N-type Bragg reflector layer 14 to the quantum well active layer 16, which can form a funnel-shaped constraint on the hole carriers, so that the hole carriers are confined in the quantum well active layer 16 as much as possible.

[0050] In this embodiment of the invention, the quantum well active layer 16 is disposed on the first waveguide layer 15, and the growth temperature of the quantum well active layer 16 is between 700 degrees Celsius and 1100 degrees Celsius.

[0051] Specifically, the quantum well active layer 16 includes at least one potential well layer 162 and at least two potential barrier layers 161 arranged alternately, with each potential well layer 162 inserted between two adjacent potential barrier layers 161; wherein, the potential well layer 162 and the potential barrier layer 161 are both made of AlInGaN multi-element material, and the only difference between the potential barrier layer 161 and the potential well layer 162 is the content of aluminum composition.

[0052] Furthermore, the total aluminum content of each potential well layer 162 is lower than the total aluminum content of each potential barrier layer 161, in order to ensure that the charge carriers in the quantum well active layer 16 are confined within the potential well layer 162.

[0053] Furthermore, the number of periods of the active quantum well layer 16 ranges from 2 to 8; the thickness of the potential well layer 162 ranges from 5 nm to 30 nm, and the Al content of the potential well layer 162 is greater than or equal to 20% and less than 100%; the thickness of the potential well layer 162 ranges from 0.1 nm to 5 nm, and the Al content is greater than 0 and less than or equal to 80%.

[0054] Furthermore, the difference between the band gap of the barrier layer 161 and the photon energy of the emitted light in the quantum well active layer 16 is greater than 0.12 eV. This is to ensure that the barrier layer 161 does not absorb photons.

[0055] In this embodiment of the invention, the second waveguide layer 17 is P-type doped Al. k2 In j2 Ga 1-k2-j2 The material is N, and the Al component content in the second waveguide layer 17 increases linearly in the direction from the quantum well active layer 16 to the P-type Bragg reflector layer 18. k2 and j2 satisfy the following relationship: 0≤k2≤1, 0≤j2≤1, 0≤k2+j2≤1.

[0056] Specifically, the thickness of the second waveguide layer 17 ranges from 30 to 500 nm; the band gap of the second waveguide layer 17 increases linearly in the direction from the quantum well active layer 16 to the P-type Bragg reflector layer 18.

[0057] In this design, the band gap of the surface of the second waveguide layer 17 in contact with the quantum well active layer 16 is equal to the band gap of the barrier layer 161, and the band gap of the surface of the second waveguide layer 17 in contact with the P-type Bragg reflector layer 18 is smaller than the band gap of the surface of the first waveguide layer 15 in contact with the N-type Bragg reflector layer 14. This design ensures that the electron mobility is greater than the hole mobility, so that the second waveguide layer 17 forms an electron blocking layer, thereby confining electron carriers as much as possible within the quantum well active layer 16.

[0058] In this embodiment of the invention, a P-type Bragg reflector 18 is disposed on the second waveguide layer 17, and the P-type Bragg reflector 18 is Al.x3 Ga y3 In 1-x3-y3 N-layer and Al x4 Ga y4 In 1-x4-y4 The periodic structure consisting of N alternating layers, x3, x4, y3 and y4 satisfy the following relationships: 0 < x3 ≤ 1, 0 ≤ y3 ≤ 1, 0 ≤ x3 + y3 ≤ 1, 0 < x4 ≤ 1, 0 ≤ y4 ≤ 1, 0 ≤ x4 + y4 ≤ 1.

[0059] Specifically, Al x3 Ga y3 In 1-x3-y3 The thickness of layer N is t3, Al x3 Ga y3 In 1-x3-y3 The average refractive index of the N layer is n3; Al x4 Ga y4 In 1-x4-y4 The thickness of layer N is t4, Al x4 Ga y4 In 1-x4-y4 The average refractive index of the N layer is n4;

[0060] Among them, t3, t4, n3 and n4 satisfy the following relationship: t3*n3=t4*n4=λ / 4.

[0061] Furthermore, the above design makes each sublayer in the superlattice periodic structure of the P-type Bragg reflector 18 a distributed Bragg mirror. On the one hand, it can further reflect more than 99% of the light that conforms to the center wavelength of the light emitted from the quantum well active layer 16 and suppress stray light that does not conform to the center wavelength of the light emitted from the quantum well active layer 16. On the other hand, it can further effectively improve the brightness of the deep ultraviolet light emitting diode 100.

[0062] Specifically, the dopant in the P-type Bragg reflector layer 18 is a magnesium-containing P-type dopant, which is beneficial for providing a large number of hole carriers and acting as a hole injection layer.

[0063] Specifically, the number of stacked layers (n) in the P-type Bragg reflector layer 18 ranges from 3 to 10. When the number of stacked layers in the N-type Bragg reflector layer 14 is less than 3, the effect of the P-type Bragg reflector layer 18 in reflecting the emitted light from the quantum well active layer 16 along the substrate 11 is not significant; when the number of stacked layers in the P-type Bragg reflector layer 18 is greater than 10, the hole input capability of the deep ultraviolet light-emitting diode 100 deteriorates.

[0064] Specifically, Al x3 Ga y3 In 1-x3-y3 N layer and Alx4 Ga y4 In 1-x4-y4 The band gap of at least one of the N layers is greater than the photon energy of the emitted light from the quantum well active layer 16. This arrangement is to reduce the absorption of emitted light from the quantum well active layer 16 by the p-type Bragg reflector layer 18.

[0065] In this embodiment of the invention, the deep ultraviolet light-emitting diode 100 further includes a P-type contact layer 19, which is disposed on a P-type Bragg reflector layer 18. The growth temperature of the P-type contact layer 19 is between 600 degrees Celsius and 900 degrees Celsius. The material of the P-type contact layer 19 is P-type doped GaN material, and the thickness of the P-type contact layer 19 is between 5 nm and 50 nm. The P-type contact layer 19 uses magnesium pyrocene as a dopant.

[0066] Furthermore, in this embodiment of the invention, the deep ultraviolet light-emitting diode 100 further includes an N-type electrode 110 and a P-type electrode 111;

[0067] The N-type contact layer 13 and the N-type Bragg reflector layer 14 form a stepped structure, and the area of ​​the N-type Bragg reflector layer 14 is smaller than the area of ​​the N-type contact layer 13. The P-type electrode 111 is disposed on the P-type contact layer 19, and the N-type electrode 110 is disposed at the stepped structure of the N-type contact layer 13.

[0068] Accordingly, embodiments of the present invention also provide an epitaxial growth method for a deep ultraviolet light-emitting diode 100; please refer to [link to relevant documentation]. Figure 1 as well as Figure 2 , Figure 2 This is a process flow diagram of the epitaxial growth method for the deep ultraviolet light-emitting diode 100 provided in an embodiment of the present invention.

[0069] Specifically, the above epitaxial growth method is carried out in a Veeco K465i MOCVD (Metal-Organic Chemical Vapor Deposition) equipment, wherein high-purity H2, high-purity N2, or a mixture of high-purity H2 and high-purity N2 are used as carrier gas, high-purity NH3 is used as N source, trimethylgallium (TMGa) is used as gallium source, trimethylindium (TMIn) is used as indium source, silane (SiH4) is used as N-type dopant, trimethylaluminum (TMAl) is used as aluminum source, and magnesium thiocene (CP2Mg) is used as P-type dopant. The pressure in the reaction chamber of the MOCVD equipment is controlled between 20 and 100 torr.

[0070] Furthermore, the specific steps of the above epitaxial growth method are as follows:

[0071] S10, an intrinsic layer 12 is epitaxially grown on a substrate 11.

[0072] Specifically, S10 also includes:

[0073] First, a substrate 11 is provided, wherein the substrate 11 is a nano-patterned sapphire material;

[0074] Subsequently, a low-temperature buffer layer was grown on substrate 11 at a growth temperature of 400°C to 800°C, with a thickness ranging from 10 nm to 50 nm.

[0075] Finally, the growth temperature is raised to between 1100 and 1300 degrees Celsius to grow an AlN template layer on the low-temperature buffer layer. The thickness of the template layer ranges from 500 nm to 4000 nm. The low-temperature buffer layer and the template layer together constitute the intrinsic layer 12.

[0076] S20, an N-type contact layer 13 is epitaxially grown on the intrinsic layer 12.

[0077] Specifically, S20 also includes:

[0078] The growth temperature was lowered to between 1000 and 1250 degrees Celsius; then, an N-type contact layer 13 was epitaxially grown on the intrinsic layer 12.

[0079] S30, an N-type Bragg reflector layer 14 is epitaxially grown on the N-type contact layer 13.

[0080] Specifically, S30 also includes:

[0081] While maintaining a constant growth temperature, an N-type Bragg reflector layer 14 is epitaxially grown on the N-type contact layer 13; specifically, the N-type Bragg reflector layer 14 includes a multi-layer stacked structure, each of which includes Al layers stacked from bottom to top. x1 Ga y1 In 1-x1-y1 N layer and Al x2 Ga y2 In 1-x2-y2 N layers;

[0082] Among them, x1 and y1 satisfy the following relationship: 0 < x1 ≤ 1, 0 ≤ y1 ≤ 1, 0 ≤ x1 + y1 ≤ 1; x2 and y2 satisfy the following relationship: 0 < x2 ≤ 1, 0 ≤ y2 ≤ 1, 0 ≤ x2 + y2 ≤ 1.

[0083] Furthermore, Al x1 Ga y1 In 1-x1-y1 The thickness of layer N is t1, Al x1 Ga y1 In 1-x1-y1 The average refractive index of the N layer is n1; Al x2 Ga y2 In 1-x2-y2 The thickness of layer N is t2, Alx2 Ga y2 In 1-x2-y2 The average refractive index of layer N is n2;

[0084] Among them, t1, t2, n1 and n2 satisfy the following relationship: t1*n1=t2*n2=λ / 4, where λ is the center wavelength of the emitted light in the active layer 16 of the quantum well.

[0085] Furthermore, the N-type Bragg reflector 14 has a period number of m, 5 <m<20。

[0086] S40, the first waveguide layer 15 is epitaxially grown on the N-type Bragg reflector layer 14.

[0087] Specifically, S40 also includes:

[0088] While maintaining a constant growth temperature, the first waveguide layer 15 is epitaxially grown on the N-type Bragg reflector layer 14.

[0089] Specifically, the first waveguide layer 15 is N-type doped Al. k1 In j1 Ga 1-k1-j1 The material is N, and the Al content in the first waveguide layer 15 decreases linearly in the direction from the N-type Bragg reflector layer 14 to the quantum well active layer 16. k1 and j1 satisfy the following relationship: 0≤k1≤1, 0≤j1≤1, 0≤k1+j1≤1.

[0090] Specifically, the thickness of the first waveguide layer 15 ranges from 50 to 1000 nm; the band gap of the first waveguide layer 15 decreases linearly in the direction from the N-type Bragg reflector layer 14 to the quantum well active layer 16, and the band gap of the surface of the first waveguide layer 15 in contact with the quantum well active layer 16 is equal to the band gap of the barrier layer 161.

[0091] S50, a quantum well active layer 16 is epitaxially grown on the first waveguide layer 15.

[0092] Specifically, the S50 also includes:

[0093] While maintaining a constant growth temperature, a quantum well active layer 16 is epitaxially grown on the first waveguide layer 15.

[0094] Specifically, the quantum well active layer 16 includes at least one potential well layer 162 and at least two potential barrier layers 161 arranged alternately, with each potential well layer 162 inserted between two adjacent potential barrier layers 161; wherein the number of periods of the quantum well active layer 16 is 2 to 8.

[0095] S60, a second waveguide layer 17 is epitaxially grown on the active layer 16 of the quantum well.

[0096] Specifically, the S60 also includes:

[0097] While maintaining a constant growth temperature, a second waveguide layer 17 is epitaxially grown on the quantum well active layer 16.

[0098] Specifically, the second waveguide layer 17 is P-type doped Al. k2 In j2 Ga 1-k2-j2 The material is N, and the Al component content in the second waveguide layer 17 increases linearly in the direction from the quantum well active layer 16 to the P-type Bragg reflector layer 18. k2 and j2 satisfy the following relationship: 0≤k2≤1, 0≤j2≤1, 0≤k2+j2≤1.

[0099] Specifically, the thickness of the second waveguide layer 17 ranges from 30 to 500 nm; the band gap of the second waveguide layer 17 increases linearly in the direction from the quantum well active layer 16 to the P-type Bragg reflector layer 18; wherein, the band gap of the surface of the second waveguide layer 17 in contact with the quantum well active layer 16 is equal to the band gap of the barrier layer 161, and the band gap of the surface of the second waveguide layer 17 in contact with the P-type Bragg reflector layer 18 is smaller than the band gap of the surface of the first waveguide layer 15 in contact with the N-type Bragg reflector layer 14.

[0100] S70, a P-type Bragg reflector layer 18 is epitaxially grown on the second waveguide layer 17.

[0101] Specifically, the S70 also includes:

[0102] While maintaining a constant growth temperature, a P-type Bragg reflector layer 18 is epitaxially grown on the second waveguide layer 17.

[0103] Specifically, the P-type Bragg reflector layer 18 is Al x3 Ga y3 In 1-x3-y3 N-layer and Al x4 Ga y4 In 1-x4-y4 The periodic structure consisting of N alternating layers, x3, x4, y3 and y4 satisfy the following relationships: 0 < x3 ≤ 1, 0 ≤ y3 ≤ 1, 0 ≤ x3 + y3 ≤ 1, 0 < x4 ≤ 1, 0 ≤ y4 ≤ 1, 0 ≤ x4 + y4 ≤ 1.

[0104] Specifically, Al x3 Ga y3 In 1-x3-y3 The thickness of layer N is t3, Al x3 Ga y3 In 1-x3-y3 The average refractive index of the N layer is n3; Al x4 Ga y4 In 1-x4-y4 The thickness of layer N is t4, Al x4 Gay4 In 1-x4-y4 The average refractive index of the N layer is n4;

[0105] Among them, t3, t4, n3 and n4 satisfy the following relationship: t3*n3=t4*n4=λ / 4.

[0106] Furthermore, the number of periods in the P-type Bragg reflector 18 is n, 3 <n<10。

[0107] S80, a P-type contact layer 19 is epitaxially grown on a P-type Bragg reflector layer 18.

[0108] Specifically, the S80 also includes:

[0109] The growth temperature is reduced to between 600 and 900 degrees Celsius, and a P-type contact layer 19 is epitaxially grown on the P-type Bragg reflector layer 18. The material of the P-type contact layer 19 is P-type doped gallium nitride, the thickness of the P-type contact layer 19 is between 5 nm and 50 nm, and magnesia pyrocene is used as the P-type dopant in the P-type contact layer 19.

[0110] Next, an N-type electrode 110 is provided at the stepped structure of the N-type contact layer 13, with the N-type electrode 110 facing and spaced apart from the N-type Bragg reflector layer 14; finally, a P-type electrode 111 is formed on the P-type contact layer 19.

[0111] Please see Figure 3 , Figure 3 This is a schematic diagram of the energy band structure of the deep ultraviolet light-emitting diode 100 near the quantum well active layer 16 provided in an embodiment of the present invention; wherein, by Figure 3 It can be seen that the band gap of the barrier layer 161 in the quantum well active layer 16 is greater than the band gap of the well layer 162; the band gap of the first waveguide layer 15 decreases linearly in the direction from the N-type Bragg reflector layer 14 to the quantum well active layer 16, and the band gap of the surface of the first waveguide layer 15 in contact with the quantum well active layer 16 is equal to the band gap of the barrier layer 161.

[0112] The band gap of the second waveguide layer 17 increases linearly in the direction from the quantum well active layer 16 to the P-type Bragg reflector layer 18; wherein, the band gap of the surface of the second waveguide layer 17 in contact with the quantum well active layer 16 is equal to the band gap of the barrier layer 161, and the band gap of the surface of the second waveguide layer 17 in contact with the P-type Bragg reflector layer 18 is smaller than the band gap of the surface of the first waveguide layer 15 in contact with the N-type Bragg reflector layer 14.

[0113] Please see Figure 4 , Figure 4This is a schematic diagram of the optical path for forward light emission in the deep ultraviolet light-emitting diode 100 provided in this embodiment of the invention. Specifically, due to the presence of the N-type Bragg reflector layer 14, the first emitted light emitted by the quantum well active layer 16 towards the substrate 11 is reflected into the first waveguide layer 15; simultaneously, due to the presence of the P-type Bragg reflector layer 18, the second emitted light emitted by the quantum well active layer 16 towards the P-type contact layer 19 is reflected into the second waveguide layer 17, thereby ensuring that the emitted light emitted by the quantum well active layer 16 is emitted from the side, thus improving the light extraction efficiency of the deep ultraviolet light-emitting diode 100 and ultimately improving the luminous efficiency of the deep ultraviolet light-emitting diode 100.

[0114] Furthermore, in order to enable the deep ultraviolet light-emitting diode 100 to achieve the effect of front light emission, the deep ultraviolet light-emitting diode 100 also includes a cup-shaped reflective support 20. When the epitaxial structure of the deep ultraviolet light-emitting diode 100 is packaged, the reflective support 20 can reflect the emitted light emitted from the side of the deep ultraviolet light-emitting diode 100, thereby enabling the deep ultraviolet light-emitting diode 100 to achieve the effect of front light emission.

[0115] Furthermore, the reflector bracket 20 is an aluminum-plated encapsulation bracket.

[0116] Specifically, a deep ultraviolet light-emitting diode 100 was prepared using the above method, and compared with a prior art deep ultraviolet light-emitting diode 100. The specific film structure of each embodiment is as follows:

[0117] Example 1:

[0118] The film structure of the deep ultraviolet light-emitting diode 100 provided in Embodiment 1 of the present invention is shown below from bottom to top as follows:

[0119] Substrate 11 is made of sapphire.

[0120] Intrinsic layer 12 includes a low-temperature buffer layer and a template layer. The material of the low-temperature buffer layer is aluminum nitride and the thickness of the low-temperature buffer layer is 20 nm. The material of the template layer is aluminum nitride and the thickness of the template layer is 2000 nm.

[0121] The N-type contact layer 13 is made of Si-doped aluminum gallium nitride material, wherein the Al component in the N-type contact layer 13 accounts for 50% of the mass percentage of the N-type contact layer 13, and the thickness is 30 nm.

[0122] N-type Bragg reflector layer 14, made of Si-doped Al. 0.9 Ga 0.1 N-layer and Al 0.5 Ga 0.5 A periodic structure composed of N alternating layers, Al 0.9 Ga 0.1The thickness of the N layer is 29 nm, Al 0.5 Ga 0.5 The thickness of the N layer is 27.5 nm, and the number of periods is 15;

[0123] The first waveguide layer 15 is made of Si-doped AlGaN material. The Al content in the first waveguide layer 15 decreases linearly from 0.7 to 0.5 in the direction from the N-type Bragg reflector layer 14 to the quantum well active layer 16. The thickness of the first waveguide layer 15 is 1000 nm.

[0124] In the active layer 16 of the quantum well, the material is aluminum gallium nitride. The Al content in the barrier layer 161 is 50%, and the thickness of the barrier layer 161 is 10nm. The Al content in the well layer 162 is 40%, and the thickness of the well layer 162 is 2nm. The number of quantum well periods is 5.

[0125] The second waveguide layer 17 is made of Mg-doped AlGaN material. The Al content in the second waveguide layer 17 increases linearly from 0.5 to 0.65 in the direction from the quantum well active layer 16 to the P-type Bragg reflector layer 18. The thickness of the second waveguide layer 17 is 200 nm.

[0126] P-type Bragg reflector layer 18, made of Mg-doped Al. 0.8 Ga 0.2 N-layer and Al 0.3 Ga 0.7 A periodic structure composed of N alternating layers, Al 0.8 Ga 0.2 The thickness of the N layer is 28 nm, Al 0.3 Ga 0.7 The thickness of the N layer is 27.2 nm, and the number of periods is 10;

[0127] P-type contact layer 19 is made of Mg-doped GaN material and has a thickness of 30 nm;

[0128] Furthermore, using conventional methods, N-type electrodes 110 are disposed on the N-type contact layer 13 and P-type electrodes 111 are disposed on the P-type contact layer 19 to form a complete epitaxial chip structure. The specific process is not described in detail here. Both the N-type electrodes 110 and the P-type electrodes 111 are multilayer composite metal materials.

[0129] Comparative Example:

[0130] The deep ultraviolet light-emitting diode 100 provided in the comparative embodiment is fabricated using conventional processes, and its film structure from bottom to top is shown below:

[0131] Substrate 11 is made of sapphire.

[0132] Intrinsic layer 12 includes a low-temperature buffer layer and a template layer. The material of the low-temperature buffer layer is aluminum nitride and the thickness of the low-temperature buffer layer is 20 nm. The material of the template layer is aluminum nitride and the thickness of the template layer is 2000 nm.

[0133] The N-type contact layer 13 is made of Si-doped aluminum gallium nitride material, wherein the Al component in the N-type contact layer 13 accounts for 50% of the mass percentage of the N-type contact layer 13, and the thickness is 30 nm.

[0134] The electron injection layer is made of Si-doped aluminum gallium nitride material, wherein the Al component in the electron injection layer accounts for 50% of the mass percentage of the electron injection layer, and the thickness is 2000 nm;

[0135] In the active layer 16 of the quantum well, the material is aluminum gallium nitride. The Al content in the barrier layer 161 is 50%, and the thickness of the barrier layer 161 is 10nm. The Al content in the well layer 162 is 40%, and the thickness of the well layer 162 is 2nm. The number of quantum well periods is 5.

[0136] The electron blocking layer is a Mg-doped monolayer AlGaN structure with a thickness of 200 nm and an Al content of 60% by mass.

[0137] The hole injection layer is made of Mg-doped aluminum gallium nitride material, with an aluminum content of 50% by mass and a thickness of 600 nm.

[0138] P-type contact layer 19 is made of Mg-doped GaN material and has a thickness of 30 nm;

[0139] Furthermore, using conventional methods, N-type electrodes 110 are disposed on the N-type contact layer 13 and P-type electrodes 111 are disposed on the P-type contact layer 19 to form a complete epitaxial chip structure. The specific process is not described in detail here. Both the N-type electrodes 110 and the P-type electrodes 111 are multilayer composite metal materials.

[0140] Finally, under a driving current of 100mA, the light output efficiency (mW) of the two deep ultraviolet light-emitting diodes 100 at an emission wavelength of 265nm was tested respectively, and the experimental results are shown in Table 1:

[0141]

[0142] Table 1

[0143] As shown in Table 1 above, comparing Example 1 with the comparative example, the deep ultraviolet light-emitting diode 100 (Example 1) provided by the present invention has a higher light output efficiency than the deep ultraviolet light-emitting diode 100 (comparative example) prepared by the standard process.

[0144] This invention proposes an epitaxial growth method for a deep ultraviolet (DUV) light-emitting diode (LED) 100. Through reflection from an N-type Bragg reflector layer 14 and a P-type Bragg reflector layer 18, a lateral light emission mode is formed. After encapsulation, the light is reflected through a cup-shaped structure to achieve front-side light emission. This invention overcomes the problem of a small back-side light emission angle and improves the luminous efficiency of the DUV 100.

[0145] In summary, unlike existing technologies, this invention provides a deep ultraviolet light-emitting diode 100, comprising, from bottom to top, a substrate 11, an intrinsic layer 12, an N-type contact layer 13, an N-type Bragg reflector layer 14, a first waveguide layer 15, a quantum well active layer 16, a second waveguide layer 17, a P-type Bragg reflector layer 18, and a P-type contact layer 19, wherein the N-type Bragg reflector layer 14 is Al x1 Ga y1 In 1-x1-y1 N-layer and Al x2 Ga y2 In 1-x2-y2 The periodic structure consists of N alternating layers, with the P-type Bragg reflector layer being Al18. x3 Ga y3 In 1-x3-y3 N-layer and Al x4 Ga y4 In 1-x4-y4 The structure is a periodic structure composed of N alternating layers, with the first waveguide layer 15 being N-type doped Al. k1 In j1 Ga 1-k1-j1 The material is N, and the Al content in the first waveguide layer 15 decreases linearly from the N-type Bragg reflector layer 14 to the quantum well active layer 16. The second waveguide layer 17 is P-type doped Al. k2 In j2 Ga 1-k2-j2The material is N, and the Al content in the second waveguide layer 17 increases linearly from the quantum well active layer 16 to the P-type Bragg reflector layer 18. This invention uses the N-type Bragg reflector layer 14 to reflect the first emitted light emitted from the quantum well active layer 16 towards the substrate 11 into the first waveguide layer 15, and uses the P-type Bragg reflector layer 18 to reflect the second emitted light emitted from the quantum well active layer 16 towards the P-type contact layer 19 into the second waveguide layer 17. This ensures that all emitted light from the quantum well active layer 16 exits from the side. This improves the light extraction efficiency of the deep ultraviolet light-emitting diode 100, thereby increasing its luminous efficiency. Simultaneously, the second waveguide layer 17, with its Al composition gradient, acts as an electron blocking layer to confine electron carriers to the quantum well active layer 16, while the first waveguide layer 15, also with its Al composition gradient, acts as a hole blocking layer to confine hole carriers to the quantum well active layer 16. This further enhances the recombination efficiency of electrons and holes in the quantum well active layer 16, ultimately improving the luminous efficiency of the deep ultraviolet light-emitting diode 100.

[0146] It should be noted that all the above embodiments belong to the same inventive concept, and the descriptions of each embodiment have different focuses. Where the description in a particular embodiment is not detailed, please refer to the description in other embodiments.

[0147] The above embodiments merely illustrate implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A deep ultraviolet light-emitting diode, characterized in that, comprises a substrate, an intrinsic layer, an N-type contact layer, an N-type Bragg reflection layer, a first waveguide layer, a quantum well active layer, a second waveguide layer, a P-type Bragg reflection layer and a P-type contact layer which are stacked from bottom to top; Wherein, the N-type Bragg reflector layer is Al x1 Ga y1 In 1-x1-y1 N-layer and Al x2 Ga y2 In 1-x2-y2 The periodic structure consists of N alternating layers, where x1, x2, y1, and y2 satisfy the following relationships: 0 < x1 ≤ 1, 0 ≤ y1 ≤ 1, 0 ≤ x1 + y1 ≤ 1, 0 < x2 ≤ 1, 0 ≤ y2 ≤ 1, 0 ≤ x2 + y2 ≤ 1; the P-type Bragg reflector layer is Al. x3 Ga y3 In 1-x3-y3 N-layer and Al x4 Ga y4 In 1-x4-y4 The periodic structure consisting of N alternating layers, x3, x4, y3 and y4 satisfy the following relationship: 0 < x3 ≤ 1, 0 ≤ y3 ≤ 1, 0 ≤ x3 + y3 ≤ 1, 0 < x4 ≤ 1, 0 ≤ y4 ≤ 1, 0 ≤ x4 + y4 ≤ 1; The first waveguide layer is an N-type doped Al. k1 In j1 Ga 1-k1-j1 The first waveguide layer is made of N-type material, and the Al content in the first waveguide layer decreases linearly from the N-type Bragg reflector layer to the quantum well active layer, with k1 and j1 satisfying the following relationships: 0≤k1≤1, 0≤j1≤1, 0≤k1+j1≤1; the second waveguide layer is made of P-type doped Al. k2 In j2 Ga 1-k2- j2 The material is N, and the Al component content in the second waveguide layer increases linearly in the direction from the quantum well active layer to the P-type Bragg reflector layer. k2 and j2 satisfy the following relationship: 0≤k2≤1, 0≤j2≤1, 0≤k2+j2≤1. wherein the band gap of the first waveguide layer decreases linearly in the direction from the N-type Bragg reflection layer to the quantum well active layer, and the band gap of the surface of the first waveguide layer in contact with the quantum well active layer is equal to the band gap of the barrier layer; the quantum well active layer is a periodic structure formed by alternately stacking barrier layers and well layers; the band gap of the second waveguide layer increases linearly in the direction from the quantum well active layer to the P-type Bragg reflection layer; the band gap of the surface of the second waveguide layer in contact with the quantum well active layer is equal to the band gap of the barrier layer, and the band gap of the surface of the second waveguide layer in contact with the P-type Bragg reflection layer is smaller than the band gap of the surface of the first waveguide layer in contact with the N-type Bragg reflection layer.

2. The deep ultraviolet light-emitting diode according to claim 1, characterized in that, The Al x1 Ga y1 In 1-x1-y1 The thickness of layer N is t1, and the Al x1 Ga y1 In 1-x1-y1 The average refractive index of the N layer is n1; the Al x2 Ga y2 In 1-x2-y2 The thickness of layer N is t2, and the Al x2 Ga y2 In 1-x2-y2 The average refractive index of layer N is n2; Where t1, t2, n1, and n2 satisfy the following relationship: t1 n1=t2 n2 = λ / 4, where λ is the center wavelength of the emitted light in the active layer of the quantum well.

3. The deep ultraviolet light-emitting diode according to claim 2, characterized in that, The Al x1 Ga y1 In 1-x1-y1 The band gap of layer N is E1, and the Al x2 Ga y2 In 1-x2-y2 The band gap of layer N is E2; wherein E1 and E2 satisfy the following relational expressions: 1240 / E1<λ, 1240 / E2<λ.

4. The deep ultraviolet light-emitting diode according to claim 2, characterized in that, The Al x3 Ga y3 In 1-x3-y3 The thickness of layer N is t3, and the Al x3 Ga y3 In 1-x3-y3 The average refractive index of the N layer is n3; the Al x4 Ga y4 In 1-x4-y4 The thickness of layer N is t4, and the Al x4 Ga y4 In 1-x4-y4 The average refractive index of the N layer is n4; Where t3, t4, n3, and n4 satisfy the following relationship: t3 n3=t4 n4 = λ / 4.

5. The deep ultraviolet light-emitting diode according to claim 4, characterized in that, The Al x3 Ga y3 In 1-x3-y3 N layer and the Al x4 Ga y4 In 1-x4-y4 The band gap of at least one of the N layers is greater than the photon energy of the emitted light in the active layer of the quantum well.

6. The deep ultraviolet light-emitting diode according to claim 1, characterized in that, The number of periods of the quantum well active layer ranges from 2 to 8; wherein the difference between the band gap of the barrier layer and the photon energy of the emergent light in the quantum well active layer is greater than 0.12eV.

7. The deep ultraviolet light-emitting diode according to claim 1, characterized in that, The number of periods of the N-type Bragg reflection layer is m, and the number of periods of the P-type Bragg reflection layer is n; wherein m ranges from 5<m<40; n ranges from 3<n<10.

8. The deep ultraviolet light-emitting diode according to claim 1, characterized in that, The thickness of the first waveguide layer ranges from 50 to 1000nm, and the thickness of the second waveguide layer ranges from 30 to 500nm.

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