Monolithic integrated deep ultraviolet light-emitting diode with current amplification structure and preparation method of monolithic integrated deep ultraviolet light-emitting diode

Abstract

The invention relates to a monolithic integrated deep ultraviolet light emitting diode with a current amplification structure and a preparation method thereof. The monolithic integrated deep ultraviolet light emitting diode comprises a substrate layer, a nucleating layer, a first n-type AlGaN layer and a second n-type AlGaN layer which are sequentially stacked from bottom to top, an active region is formed on the first side of the upper surface of the second n-type AlGaN layer, and a first p-type GaN layer is formed on the second side of the second n-type AlGaN layer; the first p-type GaN layer is in contact with the second n-type AlGaN layer so as to generate a plurality of holes; a second p-type GaN layer is formed on the active region; the first p-type GaN layer, the second n-type AlGaN layer, the active region and the second p-type GaN layer form a PNP structure so as to amplify base current and realize multiplication of hole concentration; the first p-type GaN layer, the second n-type AlGaN layer and the second p-type GaN layer are respectively provided with an electrode layer. The device can greatly improve the luminous efficiency of the deep ultraviolet light-emitting diode.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor devices, and in particular relates to a monolithic integrated deep ultraviolet light emitting diode with a current amplification structure and a preparation method thereof. Background Art

[0002] Deep ultraviolet light-emitting diodes, abbreviated as UVC LEDs, refer to light-emitting diodes that can emit ultraviolet light with a wavelength in the range of 100 to 280 nanometers (nm). At present, deep ultraviolet light-emitting diodes are mainly used in disinfection, air quality, water and wastewater quality monitoring, as well as the detection of hazardous substances and medical diagnosis.

[0003] The light-emitting principle of deep ultraviolet light-emitting diodes is similar to that of ordinary LEDs, both of which are based on the electroluminescence phenomenon of semiconductor materials. When current passes through the pn junction composed of p-type semiconductors and n-type semiconductors, minority carriers and majority carriers recombine to release energy and generate photon emission. Deep ultraviolet LEDs can emit ultraviolet light of a specific wavelength through specific semiconductor materials and structural design.

[0004] At present, deep ultraviolet light-emitting diodes are mainly made of gallium nitride (GaN) semiconductor materials, and a pn junction is obtained by preparing p-type doping on the GaN surface. The existing preparation technology often uses Mg ions to assist in the p-type doping of GaN. However, Mg has a high activation energy and a low ionization rate, which leads to a low hole concentration in P-type GaN, limiting the recombination probability of holes and electrons in the LED active area, thereby greatly restricting the luminous efficiency of deep ultraviolet light-emitting diodes. Therefore, it is urgent to provide a deep ultraviolet light-emitting diode to overcome the above problems. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a monolithic integrated deep ultraviolet light-emitting diode with a current amplification structure and a preparation method thereof. The technical problem to be solved by the present invention is achieved by the following technical solutions:

[0006] In a first aspect, the present invention provides a monolithic integrated deep ultraviolet light-emitting diode with a current amplification structure, comprising: a substrate layer, a nucleation layer, a first n-type AlGaN layer and a second n-type AlGaN layer stacked in sequence from bottom to top; an active region is formed on a first side of an upper surface of the second n-type AlGaN layer, and a first p-type GaN layer is formed on a second side of the second n-type AlGaN layer; the first p-type GaN layer is in contact with the second n-type AlGaN layer, and a plurality of holes are generated based on a nitride polarization effect; a second p-type GaN layer is formed on the active region; the first p-type GaN layer, the second n-type AlGaN layer, the active region and the second p-type GaN layer constitute a PNP structure to amplify a base current; an electrode layer is respectively provided on the first p-type GaN layer, the second n-type AlGaN layer and the second p-type GaN layer.

[0007] In some embodiments, the thickness of the first p-type GaN layer ranges from 40 nm to 60 nm, the width ranges from 150 μm to 200 μm, and the doping concentration is 1.6×10 17 cm -3 .

[0008] In some embodiments, the thickness of the second p-type GaN layer ranges from 100 nm to 150 nm, and the doping concentration is 3×10 18 cm -3 .

[0009] In some embodiments, the first n-type AlGaN layer includes: a first AlGaN sublayer, a second AlGaN sublayer, a third AlGaN sublayer, a fourth AlGaN sublayer and a fifth AlGaN sublayer; wherein the first AlGaN sublayer and the fifth AlGaN sublayer have the same thickness, the second AlGaN sublayer and the fourth AlGaN sublayer have the same thickness, the first AlGaN sublayer is thinner than the second AlGaN sublayer, and the second AlGaN sublayer is thinner than the third AlGaN sublayer.

[0010] In some embodiments, the thickness of the first AlGaN sublayer ranges from 150 nm to 180 nm, and the doping concentration is 6×10 16 cm -3 The thickness of the second AlGaN sublayer ranges from 300 nm to 350 nm, and the doping concentration is 1.6×10 17 cm -3 The thickness of the third AlGaN sublayer ranges from 1500nm to 1800nm, and the doping concentration is 1×10 18 cm -3 .

[0011] In some embodiments, the thickness of the second n-type AlGaN layer ranges from 80 nm to 120 nm, and the doping concentration is 1.6×10 15 cm -3 .

[0012] In some embodiments, the active region is composed of a plurality of Al x Ga 1-x N layer and multiple Al y Ga 1-y N layers are grown alternately, each Al x Ga 1-x The thickness of the N layer ranges from 2nm to 6nm. y Ga 1-y The thickness of the N layer ranges from 8 nm to 15 nm, and the width of the active region ranges from 150 μm to 200 μm.

[0013] In some embodiments, the material of the substrate layer is one of a c-plane sapphire substrate, a SiC substrate or a Si substrate, and the width of the substrate layer ranges from 500 μm to 600 μm.

[0014] In some embodiments, the material of the nucleation layer is AlN or GaN, and the thickness of the nucleation layer ranges from 20 nm to 40 nm.

[0015] In a second aspect, the present invention further provides a method for preparing a monolithically integrated deep ultraviolet light-emitting diode with a current amplification structure, the method being used to prepare the monolithically integrated deep ultraviolet light-emitting diode with a current amplification structure described in the first aspect above; the method comprising:

[0016] A nucleation layer is prepared on the pretreated substrate layer; a first n-type AlGaN layer is grown on the nucleation layer; a second n-type AlGaN layer is grown on the first n-type AlGaN layer; an active region is prepared on a first side of an upper surface of the second n-type AlGaN layer; a first p-type GaN layer is prepared on a second side of the second n-type AlGaN layer; a second p-type GaN layer is prepared on the active region; and an electrode layer is prepared on the first p-type GaN layer, the second n-type AlGaN layer and the second p-type GaN layer, respectively.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] Aiming at the problem that the traditional deep ultraviolet light-emitting diode has low luminous efficiency due to insufficient hole concentration, the present invention provides a monolithic integrated deep ultraviolet light-emitting diode with a current amplification structure and a preparation method thereof. The monolithic integrated deep ultraviolet light-emitting diode with the current amplification structure prepares a p-type GaN layer on the second n-type AlGaN layer to generate a large number of holes by utilizing the nitride polarization effect, thereby improving the hole concentration of the deep ultraviolet light-emitting diode, and utilizes the second n-type AlGaN layer, the active area and the second p-type GaN layer to form a PNP structure to amplify the base current and increase the hole concentration, so that the recombination probability of holes and electrons can be effectively improved in the active area without high-temperature activation, and finally the luminous efficiency of the deep ultraviolet light-emitting diode is greatly improved, and the diode has the advantages of high performance, simple structure and convenient operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a monolithically integrated deep ultraviolet light-emitting diode with a current amplification structure provided by an embodiment of the present invention;

[0020] Figure 2 It is a schematic flow chart of a method for preparing a monolithically integrated deep ultraviolet light-emitting diode with a current amplification structure provided by an embodiment of the present invention;

[0021] Figure 3 It is a schematic diagram of the preparation of a monolithic integrated deep ultraviolet light-emitting diode with a current amplification structure provided in an embodiment of the present invention.

[0022] Reference numerals:

[0023] 1. Substrate layer; 2. Nucleation layer; 3. First n-type AlGaN layer; 4. Second n-type AlGaN layer; 5. Active region; 6. First p-type GaN layer; 7. Second p-type GaN layer; 8. Electrode layer; 31. First AlGaN sublayer; 32. Second AlGaN sublayer; 33. Third AlGaN sublayer; 34. Fourth AlGaN sublayer; 35. Fifth AlGaN sublayer; 81. First electrode layer; 82. Second electrode layer; 83. Third electrode layer. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0025] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0026] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "one" or "an" does not exclude multiple situations. A single processor or other unit may implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0027] Now, in conjunction with the accompanying drawings, a monolithic integrated deep ultraviolet light emitting diode with a current amplification structure and a preparation method thereof provided by an embodiment of the present invention are described in detail.

[0028] Figure 1 Schematic diagram of a monolithic integrated deep ultraviolet light emitting diode with a current amplification structure provided by an embodiment of the present invention. It should be noted that, in order to see clearly, Figure 1 Different colors are used to distinguish the layers in the Figure 1 It is only used to reflect the positional relationship between layers, not the actual height of each layer.

[0029] like Figure 1As shown, the structure includes: a substrate layer 1, a nucleation layer 2, a first n-type AlGaN layer 3 and a second n-type AlGaN layer 4 stacked in sequence from bottom to top; an active region 5 is formed on the first side of the upper surface of the second n-type AlGaN layer 4, and a first p-type GaN layer 6 is formed on the second side of the second n-type AlGaN layer 4; the first p-type GaN layer 6 is in contact with the second n-type AlGaN layer 4, and a plurality of holes (not shown in the figure) are generated based on the nitride polarization effect; a second p-type GaN layer 7 is formed on the active region 5; the first p-type GaN layer 6, the second n-type AlGaN layer 4, the active region 5 and the second p-type GaN layer 7 constitute a PNP structure to amplify the base current; an electrode layer 8 is respectively provided on the first p-type GaN layer 6, the second n-type AlGaN layer 4 and the second p-type GaN layer 7.

[0030] Here, the material of the substrate layer 1 is one of a c-plane sapphire substrate, a SiC substrate or a Si substrate, the width of the substrate layer 1 is in the range of 500 μm to 600 μm, preferably 500 μm, and the thickness is in the range of 300 μm to 600 μm, preferably 500 μm. Also, the material of the nucleation layer 2 is AlN, and the thickness of the nucleation layer 2 is in the range of 20 nm to 40 nm, preferably 25 nm.

[0031] Here, the first n-type AlGaN layer 3 includes: a first AlGaN sublayer 31, a second AlGaN sublayer 32, a third AlGaN sublayer 33, a fourth AlGaN sublayer 34 and a fifth AlGaN sublayer 35; wherein the first AlGaN sublayer 31 and the fifth AlGaN sublayer 35 have the same thickness, the second AlGaN sublayer 32 and the fourth AlGaN sublayer 34 have the same thickness, the first AlGaN sublayer 31 has a thickness less than the second AlGaN sublayer 32, and the second AlGaN sublayer 32 has a thickness less than the third AlGaN sublayer 33. Specifically, the thickness of the first AlGaN sublayer 31 ranges from 150 nm to 180 nm, and the doping concentration is 6×10 16 cm -3 The thickness of the second AlGaN sublayer 32 ranges from 300 nm to 350 nm, and the doping concentration is 1.6×10 17 cm -3 The thickness of the third AlGaN sublayer 33 ranges from 1500 nm to 1800 nm, and the doping concentration is 1×10 18 cm -3 .

[0032] It should be noted that the doping concentration of the first AlGaN sublayer 31 is the same as the doping concentration of the fifth AlGaN sublayer 35 , and the doping concentration of the second AlGaN sublayer 32 is the same as the doping concentration of the fourth AlGaN sublayer 34 .

[0033] Here, the thickness of the second n-type AlGaN layer 4 ranges from 80 nm to 120 nm, and the doping concentration is 1.6×10 15 cm -3 .

[0034] Here, the active region 5 is composed of a plurality of Al x Ga 1-x N layer and multiple Al y Ga 1-y N layers are grown alternately, each Al x Ga 1-x The thickness of the N layer ranges from 2nm to 6nm. y Ga 1-y The thickness of the N layer ranges from 8 nm to 15 nm, and the width of the active region 5 ranges from 150 μm to 200 μm. For example, the number of alternations is 5. First, the first Al x Ga 1-x N layer, in the first Al x Ga 1-x The first Al y Ga 1-y N layer, then in the first Al y Ga 1-y A second Al x Ga 1-x N layer, in the second Al x Ga 1-x The second Al layer is superimposed on the N layer y Ga 1-y N layers are repeatedly stacked alternately until the fifth Al y Ga 1-y N layer, obtaining active region 5.

[0035] Here, Al x Ga 1-x The value of x in N is between 0 and 0.5. y Ga 1-y The value of y in N is between 0.4 and 0.7. In a possible implementation, the active region 5 is composed of 5 Al 0.5 Ga 0.5 N layer and 5 Al 0.6 Ga 0.4 N layers are grown alternately, each Al 0.5 Ga 0.5 The thickness of the N layer is 3nm, and each Al 0.6 Ga 0.4 The thickness of the N layer is 9 nm.

[0036] Here, the thickness of the second n-type AlGaN layer 4 ranges from 80 nm to 120 nm, and the doping concentration is 1.6×10 15 cm -3 Here, the material of the second n-type AlGaN layer 4 is Al x GaN 1-x , the value of x is between 0 and 0.5.

[0037] Here, the thickness of the first p-type GaN layer 6 is in the range of 40 nm to 60 nm, the width is in the range of 150 μm to 200 μm, preferably 150 μm, and the doping concentration is 1.6×10 17 cm -3 The thickness of the second p-type GaN layer 7 is in the range of 100 nm to 150 nm, and the doping concentration is 3×10 18 cm -3 It should be noted that the width of the second p-type GaN layer 7 is the same as the width of the active region 5 , and the width ranges from 150 μm to 200 μm.

[0038] Here, a first electrode layer 81 is arranged on the first p-type GaN layer 6, a second electrode layer 82 is arranged on the second n-type AlGaN layer 4, and a third electrode layer 83 is arranged on the second p-type GaN layer 7. Here, the materials and structures of the first electrode layer 81, the second electrode layer 82 and the third electrode layer 83 are the same, and the width of each electrode layer is greater than or equal to 50μm. In addition, the first electrode layer 81 and the third electrode layer 83 are both p-type electrodes, and the second electrode layer 82 is an n-type electrode. The second electrode layer 82 is specifically arranged between the first p-type GaN layer 6 and the active area 5, and the three are arranged at intervals.

[0039] In actual operation, the current inflow path is: entering from the first electrode layer 81, passing through the first p-type GaN layer 6, the second n-type AlGaN layer 4, the active region 5 and the second p-type GaN layer 7, and flowing out from the third electrode layer 83; the outflow path is: flowing out from the third electrode layer 83, the second p-type GaN layer 7, the active region 5, the second n-type AlGaN layer 4 to the second electrode layer 82. Since the first p-type GaN layer 6 is in contact with the second n-type AlGaN layer 4, a number of holes (also referred to as hole gas) can be formed based on the nitride polarization effect of the material, which greatly increases the hole concentration in the P-type GaN, and the PNP structure composed of the first p-type GaN layer 6, the second n-type AlGaN layer 4, the active region 5 and the second p-type GaN layer 7 can amplify the base current inside the deep ultraviolet light-emitting diode, increase the hole concentration, thereby effectively improving the recombination probability of holes and electrons in the active region, and greatly improving the luminous efficiency of the deep ultraviolet light-emitting diode.

[0040] Corresponding to the monolithic integrated deep ultraviolet light emitting diode with a current amplification structure provided in the above-mentioned embodiment of the present invention, the embodiment of the present invention also provides a method for preparing a monolithic integrated deep ultraviolet light emitting diode with a current amplification structure, and the preparation method can be used to prepare the monolithic integrated deep ultraviolet light emitting diode with a current amplification structure provided in the embodiment of the present invention. Figure 2 It is a schematic flow chart of a method for preparing a monolithically integrated deep ultraviolet light-emitting diode with a current amplification structure provided by an embodiment of the present invention; Figure 3 Schematic diagram of the preparation of a monolithic integrated deep ultraviolet light-emitting diode with a current amplification structure provided by an embodiment of the present invention. It should be noted that: Figure 3 The direction of the arrows in the figure represents the preparation order of the device, and for the sake of simplicity and to facilitate the clear identification of the newly added parts, in each small figure, the components that have appeared in the previous small figure are not numbered, and only the newly added components in the current small figure are numbered. Figure 2 and Figure 3 , the preparation method is described in detail.

[0041] Please refer to Figure 2 and Figure 3 , the preparation method includes steps S110-S170; specifically:

[0042] S110: preparing a nucleation layer 2 on the pre-treated substrate layer 1.

[0043] Here, the material of the substrate layer 1 is a c-plane sapphire substrate. The c-plane sapphire substrate layer is cleaned to remove dust and other impurities on the surface, and then placed in a metal organic chemical vapor deposition (MOCVD) chamber, and the reaction chamber is evacuated to a vacuum degree of 2×10 -2 Torr; hydrogen is introduced into the reaction chamber, and when the pressure of the reaction chamber reaches about 52 Torr, the c-plane sapphire substrate is heated to 900°C for 5 minutes to complete the pretreatment of the substrate layer 1. Subsequently, the pretreated c-plane sapphire substrate is placed in a reaction chamber at 1100°C, and ammonia gas with a flow rate of 3200sccm is introduced for 5 minutes to complete nitridation; subsequently, a MOCVD process is used to grow a nucleation layer 2 on the substrate layer 1 after nitridation treatment at 1000°C, ammonia gas with a flow rate of 3200sccm and an aluminum source with a flow rate of 42sccm in the reaction chamber environment, as shown in FIG. Figure 3 As shown in (1) in .

[0044] S120 : growing a first n-type AlGaN layer 3 on the nucleation layer 2 .

[0045] The MOCVD process was used to control the temperature of the reaction chamber to 1000°C. At the same time, 2600sccm of ammonia, 150sccm of gallium source, 300sccm of aluminum source and 5sccm of silicon source were introduced. When the pressure was maintained at 20Torr, a doping concentration of 6×10 16 cm -3 A first AlGaN sublayer 31;

[0046] Then, the flow rates of ammonia, gallium source, and aluminum source were kept unchanged, and the flow rate of silicon source was adjusted to 8 sccm. A doping concentration of 1.6×10 17 cm -3 A second AlGaN sublayer 32;

[0047] Keeping the flow rates of ammonia, gallium source, and aluminum source unchanged, the flow rate of silicon source is adjusted to 22 sccm, and a doping concentration of 1×10 18 cm -3 A third AlGaN sublayer 33;

[0048] Keep the flow rates of ammonia, gallium source, and aluminum source unchanged, adjust the flow rate of silicon source to 8 sccm, and prepare a doping concentration of 1.6×10 17 cm -3 A fourth AlGaN sublayer 34;

[0049] Keep the flow rates of ammonia, gallium source, and aluminum source unchanged, adjust the flow rate of silicon source to 5 sccm, and prepare a doping concentration of 6×10 16 cm -3 The fifth AlGaN sublayer 35 is obtained to obtain the first n-type AlGaN layer 3, such as Figure 3 As shown in (2) in .

[0050] S130 : growing a second n-type AlGaN layer 4 on the first n-type AlGaN layer 3 .

[0051] Here, the MOCVD process is used to keep the flow rates of ammonia, gallium source, and aluminum source unchanged, and the flow rate of silicon source is adjusted to 3 sccm. The doping concentration of 1.6×10 15 cm -3 The second n-type AlGaN layer 4, such as Figure 3 As shown in (3) in .

[0052] S140 : preparing an active region 5 on a first side of an upper surface of the second n-type AlGaN layer 4 .

[0053] Here, on the right side of the second n-type AlGaN layer 4, five Al layers are grown alternately by MOCVD process at a reaction chamber temperature of 1000°C and a pressure of 20 Torr. x Ga 1-x N layer and Al y Ga 1-y N layer, and the active region 5 is obtained, such as Figure 3 Specifically, during the growth process, the flow rate of the nitrogen source is controlled to be maintained at 1100 sccm, and the Al growth x Ga 1-x When the N layer is grown, the gallium source flow rate is controlled to 60sccm and the aluminum source flow rate is 300sccm. y Ga 1-y In the N layer, the gallium source flow rate is controlled to be 40 sccm and the aluminum source flow rate is controlled to be 400 sccm.

[0054] S150 : forming a first p-type GaN layer 6 on the second side of the second n-type AlGaN layer 4 .

[0055] Here, on the left side of the second n-type AlGaN layer 4, a first p-type GaN layer 6 is grown by using an MOCVD process at a reaction chamber temperature of 1000°C, with a flow rate of 2600 sccm of ammonia, 150 sccm of gallium source and 60 sccm of magnesium source, and a pressure of 20 Torr. Figure 3 As shown in (5) in .

[0056] S160 : preparing a second p-type GaN layer 7 on the active region 5 .

[0057] Here, on the active region 5, a second p-type GaN layer 7 is grown by using MOCVD process at a reaction chamber temperature of 1000° C., with a flow rate of 2600 sccm of ammonia, 150 sccm of gallium source and 100 sccm of magnesium source, and a pressure of 20 Torr. Figure 3 As shown in (6) in .

[0058] S170 : preparing an electrode layer 8 on the first p-type GaN layer 6 , the second n-type AlGaN layer 4 and the second p-type GaN layer 7 , respectively.

[0059] Here, a metal sputtering method is used to deposit a first electrode layer 81 on the first p-type GaN layer 6, a second electrode layer 82 on the second n-type AlGaN layer 4, and a third electrode layer 83 on the second p-type GaN layer 7, and finally a monolithic integrated deep ultraviolet light-emitting diode with a current amplification structure is obtained, such as Figure 3 As shown in (7) in .

[0060] Aiming at the problem that the traditional deep ultraviolet light-emitting diode has low luminous efficiency due to insufficient hole concentration, the present invention provides a monolithic integrated deep ultraviolet light-emitting diode with a current amplification structure and a preparation method thereof. The monolithic integrated deep ultraviolet light-emitting diode with the current amplification structure prepares a p-type GaN layer on the second n-type AlGaN layer to generate a large number of holes by utilizing the nitride polarization effect, thereby improving the hole concentration of the deep ultraviolet light-emitting diode, and utilizes the second n-type AlGaN layer, the active area and the second p-type GaN layer to form a PNP structure to amplify the base current and increase the hole concentration, so that the recombination probability of holes and electrons can be effectively improved in the active area without high-temperature activation, and finally the luminous efficiency of the deep ultraviolet light-emitting diode is greatly improved, and the diode has the advantages of high performance, simple structure and convenient operation.

[0061] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A monolithic integrated deep ultraviolet light emitting diode with a current amplification structure, characterized in that: include: A substrate layer (1), a nucleation layer (2), a first n-type AlGaN layer (3) and a second n-type AlGaN layer (4) stacked in sequence from bottom to top; An active region (5) is formed on a first side of the upper surface of the second n-type AlGaN layer (4), and a first p-type GaN layer (6) is formed on a second side of the second n-type AlGaN layer (4); the first p-type GaN layer (6) is in contact with the second n-type AlGaN layer (4), and a plurality of holes are generated based on a nitride polarization effect; A second p-type GaN layer (7) is formed on the active region (5); the first p-type GaN layer (6), the second n-type AlGaN layer (4), the active region (5) and the second p-type GaN layer (7) form a PNP structure to amplify the base current; An electrode layer (8) is respectively arranged on the first p-type GaN layer (6), the second n-type AlGaN layer (4) and the second p-type GaN layer (7).

2. The monolithic integrated deep ultraviolet light emitting diode of the current amplification structure according to claim 1, characterized in that: The thickness of the first p-type GaN layer (6) is in the range of 40 nm to 60 nm, the width is in the range of 150 μm to 200 μm, and the doping concentration is 1.6×10 17 cm -3 .

3. The monolithic integrated deep ultraviolet light emitting diode of the current amplification structure according to claim 1, characterized in that: The thickness of the second p-type GaN layer (7) is in the range of 100 nm to 150 nm, and the doping concentration is 3×10 18 cm -3 .

4. The monolithic integrated deep ultraviolet light emitting diode of the current amplification structure according to claim 1, characterized in that: The first n-type AlGaN layer (3) comprises: a first AlGaN sublayer (31), a second AlGaN sublayer (32), a third AlGaN sublayer (33), a fourth AlGaN sublayer (34) and a fifth AlGaN sublayer (35); The first AlGaN sublayer (31) and the fifth AlGaN sublayer (35) have the same thickness, the second AlGaN sublayer (32) and the fourth AlGaN sublayer (34) have the same thickness, the first AlGaN sublayer (31) has a thickness smaller than the second AlGaN sublayer (32), and the second AlGaN sublayer (32) has a thickness smaller than the third AlGaN sublayer (33).

5. The monolithic integrated deep ultraviolet light emitting diode of the current amplification structure according to claim 4, characterized in that: The thickness of the first AlGaN sublayer (31) ranges from 150 nm to 180 nm, and the doping concentration is 6×10 16 cm -3 The thickness of the second AlGaN sublayer (32) is in the range of 300 nm to 350 nm, and the doping concentration is 1.6×10 17 cm -3 The thickness of the third AlGaN sublayer (33) is in the range of 1500nm to 1800nm, and the doping concentration is 1×10 18 cm -3 .

6. The monolithic integrated deep ultraviolet light emitting diode of the current amplification structure according to claim 1, characterized in that: The thickness of the second n-type AlGaN layer (4) ranges from 80 nm to 120 nm, and the doping concentration is 1.6×10 15 cm -3 .

7. The monolithic integrated deep ultraviolet light emitting diode of the current amplification structure according to claim 1, characterized in that: The active region (5) is composed of a plurality of Al x Ga 1-x N layer and multiple Al y Ga 1-y N layers are grown alternately, each Al x Ga 1-x The thickness of the N layer ranges from 2nm to 6nm. y Ga 1-y The thickness of the N layer ranges from 8 nm to 15 nm, and the width of the active region (5) ranges from 150 μm to 200 μm.

8. The monolithic integrated deep ultraviolet light emitting diode of the current amplification structure according to claim 1, characterized in that: The material of the substrate layer (1) is one of a c-plane sapphire substrate, a SiC substrate or a Si substrate, and the width of the substrate layer (1) ranges from 500 μm to 600 μm.

9. The monolithic integrated deep ultraviolet light emitting diode of the current amplification structure according to claim 1, characterized in that: The material of the nucleation layer (2) is AlN, and the thickness of the nucleation layer (2) ranges from 20 nm to 40 nm.

10. A method for preparing a monolithically integrated deep ultraviolet light-emitting diode with a current amplification structure, characterized in that: The preparation method is used to prepare the monolithic integrated deep ultraviolet light-emitting diode of the current amplification structure described in claims 1 to 9 above; The preparation method comprises: Preparing a nucleation layer (2) on the pretreated substrate layer (1); Growing a first n-type AlGaN layer (3) on the nucleation layer (2); Growing a second n-type AlGaN layer (4) on the first n-type AlGaN layer (3); Preparing an active region (5) on a first side of the upper surface of the second n-type AlGaN layer (4); forming a first p-type GaN layer (6) on a second side of the second n-type AlGaN layer (4); Preparing a second p-type GaN layer (7) on the active area (5); An electrode layer (8) is prepared on the first p-type GaN layer (6), the second n-type AlGaN layer (4) and the second p-type GaN layer (7), respectively.

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