A deep ultraviolet light emitting diode device structure and a preparation method thereof

Abstract

The application relates to a deep ultraviolet light emitting diode device structure and a preparation method for realizing hole acceleration, belonging to the field of semiconductor photodiodes, and comprising a substrate, a buffer layer and an n-type semiconductor electron injection layer from bottom to top; a plurality of quantum well active regions, a p-type AlGaN electron blocking layer, a p-type AlGaN insertion layer, an n-type AlGaN insertion layer, a p-type semiconductor hole injection layer, a p-type contact layer and a p-type electrode are sequentially arranged above one side of the n-type semiconductor electron injection layer; and an n-type electrode is arranged above the other side; the Al component percentage of the p-type AlGaN insertion layer and the n-type AlGaN insertion layer is higher than that of the p-type AlGaN hole injection layer and lower than that of the p-type AlGaN electron blocking layer. The application introduces the insertion layer, can improve the kinetic energy of holes, increases the injection of holes, optimizes the Al component of the structure, reduces the valence band offset between the electron blocking layer and the hole injection layer, and weakens the hole blocking effect.

Description

Technical Field

[0001] This invention relates to a deep ultraviolet light-emitting diode device structure and fabrication method for realizing hole acceleration, belonging to the field of semiconductor photodiode technology. Background Technology

[0002] AlGaN-based deep ultraviolet light-emitting diodes (DUV LEDs), with their advantages of small size, low power consumption, long lifespan, and high safety, have enormous development potential and application market in fields such as optical communication, sterilization and disinfection, air and water purification, and solid-state lighting.

[0003] Over the past decade or so, although LEDs have made significant breakthroughs in applications, and AlGaN-based deep ultraviolet (DUV) LEDs have been partially commercialized, many problems remain to be solved, severely hindering the further promotion of LED devices. Currently, the main problem facing AlGaN-based DUV LEDs is their relatively low external quantum efficiency (EQE), with most LED devices having an EQE of less than 10%, far lower than the 84.3% of nitride blue LEDs. Simultaneously, as the demand for LED light output power increases, the operating current density also increases accordingly, and the resulting efficiency degradation further affects the light output power. This is mainly due to the significant difference in the effective mass of electrons and holes, and the substantial difference in their migration capabilities within AlGaN, with electron mobility being much greater than hole mobility, reducing hole injection efficiency. Furthermore, for AlGaN materials with high Al content, as the Al content increases, the activation energy of the Mg acceptor increases significantly, while p-type doping becomes relatively difficult. Therefore, the hole concentration in the p-type region is often lower than the electron concentration in the n-type region, which exacerbates the transport imbalance between electrons and holes in the device. Carrier transport imbalances cause electrons to leak into the p-type region, where they recombine nonradiatively with holes, reducing the radiative recombination rate in the active region and further weakening the hole injection efficiency. Lower hole injection efficiency makes it difficult to achieve high optical output power and also leads to a severe efficiency droop effect.

[0004] Based on the above analysis, it is necessary to design a structure that can improve hole injection efficiency. This structure can improve the problems of low external quantum efficiency and severe efficiency droop in deep ultraviolet LEDs by increasing hole drift velocity, thus providing more possibilities for the large-scale commercial application and industrialization of deep ultraviolet LEDs. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a deep ultraviolet light-emitting diode device structure and fabrication method for achieving hole acceleration. The introduction of this structure can increase the kinetic energy of holes and enhance hole injection. Furthermore, the Al composition of this structure is optimized to reduce the valence band offset between the electron blocking layer and the hole injection layer, thereby weakening the hole blocking effect.

[0006] The present invention adopts the following technical solution:

[0007] A deep ultraviolet light-emitting diode device structure for hole acceleration includes, from bottom to top, a substrate, a buffer layer, and an n-type semiconductor electron injection layer. On one side of the n-type semiconductor electron injection layer, there are sequentially arranged a multi-quantum-well active region, a p-type AlGaN electron blocking layer, a p-type AlGaN insertion layer, an n-type AlGaN insertion layer, a p-type semiconductor hole injection layer, a p-type contact layer, and a p-type electrode. On the other side of the n-type semiconductor electron injection layer, there is an n-type electrode.

[0008] The percentage of Al composition in both p-type and n-type AlGaN insertion layers is higher than that in p-type AlGaN hole injection layers but lower than that in p-type AlGaN electron blocking layers. The Al compositions of p-type and n-type AlGaN insertion layers can be the same or different, as long as their Al composition percentages are higher than those in p-type AlGaN hole injection layers but lower than those in p-type AlGaN electron blocking layers.

[0009] Preferably, the doping concentration of both the p-type AlGaN insertion layer and the n-type AlGaN insertion layer is 1×10⁻⁶. 17 cm -3 ~4×10 17 cm -3 The thickness is 2nm to 10nm; preferably, the doping concentration is 2×10⁻⁶. 17 cm -3 The thickness of each is 5nm.

[0010] Preferably, the substrate is made of one of sapphire, silicon carbide (SiC), aluminum nitride (AlN), gallium nitride (GaN), or silicon (Si).

[0011] Generally, for AlGaN materials with high Al content, the activation energy of the Mg acceptor increases linearly with the increase of Al content, resulting in lower activation efficiency and making it difficult to fabricate AlGaN-based deep ultraviolet LEDs with high hole concentration and high Al content. The carrier injection efficiency is suppressed. In addition, an AlGaN layer with high Al content is epitaxially grown between the active region and the hole injection layer to suppress electron leakage. However, there is a large valence band shift between the electron blocking layer and the hole injection layer with high Al content. Many carriers cannot overcome this large interfacial barrier and are bounced back into the p-type hole injection layer, which seriously affects the carrier concentration and distribution in the active region. This reduces the light output power of the deep ultraviolet LED and limits the further commercial development of AlGaN-based deep ultraviolet LEDs.

[0012] The main problem to be solved by this invention is to provide a deep ultraviolet light-emitting diode and its fabrication method to achieve hole acceleration and solve the problem of insufficient carrier injection efficiency caused by insufficient hole kinetic energy. The secondary problem is to provide a deep ultraviolet light-emitting diode and its fabrication method to introduce a current spreading layer, thereby reducing device damage and energy loss caused by Joule heating effect in the operation of DUV LED by increasing the lateral current spreading.

[0013] This invention epitaxially grows a composite insertion layer between an electron blocking layer and a hole injection layer. This composite insertion layer consists of a p-type AlGaN insertion layer and an n-type AlGaN insertion layer along the epitaxial direction. This technique generates a built-in electric field along the [000-1] direction between the electron blocking layer and the hole injection layer, accelerating holes and increasing their kinetic energy to enhance hole injection. Furthermore, by adjusting the Al composition of the insertion layer, the valence band shift between the electron blocking layer and the hole injection layer can be reduced, weakening the blocking effect of the electron blocking layer on holes and further increasing the hole injection efficiency, thereby achieving high external quantum efficiency and optical power.

[0014] A method for fabricating the above-mentioned deep ultraviolet light-emitting diode device structure that achieves hole acceleration includes the following steps:

[0015] (1) An AlN buffer layer is grown on the surface of a sapphire substrate in the reaction chamber of MOCVD;

[0016] (2) In the reaction chamber of MOCVD, an n-type semiconductor electron injection layer is grown on the buffer layer of step (1), the material of which is AlGaN, and an n-type semiconductor is formed by introducing Si doping.

[0017] (3) In the MOCVD reaction chamber, Al is alternately grown on the n-type semiconductor electron injection layer from step (2). m Ga 1-m N-barrier layer and Al n Ga 1-nN potential well layers form a multi-quantum well active region, wherein the Al component m in the barrier layer should be greater than the Al component n in the potential well layer;

[0018] (4) In the reaction chamber of MOCVD, an AlGaN electron blocking layer is grown on the multi-quantum well active region composed of a periodic barrier layer and a potential well layer in step (3), and p-type AlGaN electron blocking layer is formed by introducing Mg impurities for p-type doping.

[0019] (5) In the reaction chamber of MOCVD, an AlGaN thin layer is grown on the surface of the p-type AlGaN electron blocking layer in step (4), and Mg impurities are introduced for p-type doping to form a p-type AlGaN insertion layer.

[0020] (6) In the reaction chamber of MOCVD, an AlGaN thin layer of the same thickness is grown on the surface of the p-type AlGaN insertion layer obtained in step (4), and Si doping is introduced to perform n-type doping to form an n-type AlGaN insertion layer.

[0021] (7) In the reaction chamber of MOCVD, a p-type AlGaN hole injection layer is grown on the surface of the n-type AlGaN insertion layer obtained in step (6), and p-type doping is performed by introducing Mg impurities.

[0022] (8) In the reaction chamber of MOCVD, a p-type contact layer is grown on the surface of the p-type AlGaN hole injection layer obtained in step (7), the material of which is GaN, and p-type heavy doping is performed by introducing Mg impurities.

[0023] (9) Next, the mesa of the AlGaN-based deep ultraviolet light-emitting diode is etched through photolithography, etching and other steps, and a part of the n-type semiconductor electron injection layer is exposed. Then, the p-type electrode and n-type electrode are fabricated through photolithography, electron beam evaporation and other processes.

[0024] Preferably, in the MOCVD growth process, at a growth temperature of 800°C, trimethylgallium or triethylgallium is used as the gallium source, trimethylaluminum is used as the aluminum source, ammonia is used as the nitrogen source, silane is used as the Si impurity source, and magnesia-dicenocene is used as the Mg impurity source.

[0025] Preferably, in step (2), the Al composition of the AlGaN material in the n-type semiconductor electron injection layer ranges from 0% to 100%, and the doping concentration is 6 × 10⁻⁶. 18 ~9×10 18 cm -3 The thickness is 3.5μm to 4.5μm;

[0026] Preferably, the Al composition is 60% and the doping concentration is 8 × 10⁻⁶. 18 cm -3The thickness is 4μm.

[0027] Preferably, in step (3), the percentage of Al component in the barrier layer of the active region is 50% to 100%, preferably 57%, and the percentage of Al component in the well layer is 0% to m%, preferably 45%.

[0028] Preferably, in step (4), the Al composition of the p-type AlGaN electron blocking layer is 60% to 100%, and the thickness is 5 to 10 nm;

[0029] The preferred Al content is 60%, and the thickness is 10 nm.

[0030] Preferably, in step (7), the thickness of the p-type AlGaN hole injection layer is 45 nm to 55 nm, and the doping concentration is 1 × 10⁻⁶. 17 cm -3 ~3×10 17 cm -3 ;

[0031] Preferably, the thickness is 50 nm and the doping concentration is 1 × 10⁻⁶. 17 cm -3 .

[0032] Preferably, the Al composition of the p-type AlGaN hole injection layer is 35% to 45%, and more preferably 40%.

[0033] To improve hole injection efficiency, a composite structure is proposed between the electron blocking layer and the hole injection layer. This composite structure consists of a p-type AlGaN insertion layer and an n-type AlGaN insertion layer along the epitaxial direction to achieve hole acceleration. First, a p-type AlGaN insertion layer and an n-type AlGaN insertion layer structure are epitaxially grown above the electron blocking layer to construct the hole acceleration region. Under the influence of applied voltage and polarization charge, the Mg acceptor ionizes, releasing holes and leaving behind negative charge centers. Simultaneously, the Si donor ionizes under the applied voltage, releasing electrons and leaving behind positive charge centers. The positive and negative charge centers can generate a built-in electric field from the n-type AlGaN layer to the p-type hole injection layer (along the [000-1] direction), which can accelerate the holes from the hole injection layer, increase their kinetic energy, and increase the number of holes that can overcome the electron blocking layer.

[0034] Furthermore, by adjusting the Al composition in the composite structure—with the percentage of Al composition in the insertion layer being higher than that in the p-type AlGaN hole injection layer and lower than that in the electron blocking layer—the significant valence band shift between the electron blocking layer and the hole injection layer is adjusted. This weakens the hole blocking effect of the electron blocking layer, further increasing the number of holes injected into the active region. Moreover, the effective conduction band barrier height (the difference between the highest conduction band level and the quasi-Fermi level of the electron blocking layer) is also increased, thereby greatly reducing the number of electrons leaking into the p-type hole region.

[0035] Introducing p-type and n-type doped layer structures between the electron blocking layer and hole injection layer of a deep ultraviolet light-emitting diode (DUV) can be achieved in MOCVD by using H2 as a carrier gas and introducing Mg and Si sources respectively during the growth of different doped layers, thus completing the growth of an n-type and p-type composite structure.

[0036] Finally, the TCAD simulation-assisted analysis in this invention, which uses the introduction of n-type and p-type composite structures to assist in the analysis of the impact on the performance of DUV LEDs, can save a lot of time and cost and better guide the subsequent DUV LED fabrication process.

[0037] For any details not covered in this invention, please refer to the prior art.

[0038] The beneficial effects of this invention are as follows:

[0039] This invention introduces a composite structure with p-type and n-type doping into the epitaxial structure of a conventional deep ultraviolet (DUV) light-emitting diode (LED), inserting it between an electron blocking layer and a hole injection layer. The doping concentration can be light or heavy, and the thickness of this composite structure can be arbitrarily set. Furthermore, the p-type layer is epitaxially layered before the n-type layer to utilize the ionized positive and negative charge centers to form an accelerating electric field opposite to the epitaxial direction. This structure increases the kinetic energy of holes, enhances hole injection, and thus improves the radiative recombination rate of the DUV. Simultaneously, the n-type layer acts as a current spreading layer, reducing Joule heating generated during LED operation, extending device lifespan, and achieving better photoelectric characteristics.

[0040] Simultaneously, the Al composition of this structure can be optimized to reduce the valence band offset between the electron blocking layer and the hole injection layer, thus weakening the hole blocking effect. This also reduces the effective conduction band barrier height of the electron blocking layer and increases its effective valence band barrier height, improving hole injection while suppressing electron leakage, enhancing radiative recombination in the active region, and achieving higher light output power and external quantum efficiency. Furthermore, the introduction of this structure has almost no impact on the voltage-current characteristic curve of the DUV LED, indicating that under the same power loss, this deep ultraviolet light-emitting diode can achieve better light output characteristics, thus proving the high efficiency of this structure. Attached Figure Description

[0041] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0042] Figure 1 A schematic diagram of a deep ultraviolet light-emitting diode device structure for hole acceleration according to an embodiment of the present invention;

[0043] Figure 2 The diagram shows the electric field distribution of Embodiment 1 of the present invention and a standard deep ultraviolet light-emitting diode at a partial electron blocking layer and a partial hole injection layer.

[0044] Figure 3 The diagram shows the energy band structure, where (a) is a partial valence band structure of the last quantum barrier, electron blocking layer, p-type AlGaN insertion layer and hole injection layer in a standard deep ultraviolet light-emitting diode; and (b) is a partial valence band structure of the last quantum barrier, electron blocking layer, p-type AlGaN insertion layer, n-type AlGaN insertion layer and hole injection layer in Embodiment 1 of the present invention.

[0045] Figure 4 The current-voltage diagrams are for a standard deep ultraviolet light-emitting diode (i.e., Comparative Example 1) and Embodiment 1 of the present invention.

[0046] Figure 5 The diagrams show a comparison of the hole concentration distribution and electron concentration in the active layer of the deep ultraviolet light-emitting diode (DUV) and Embodiment 1 of the present invention. (a) shows the hole concentration distribution in the active layer, and (b) shows the electron concentration distribution in the active layer. For clarity of comparison, the horizontal axis corresponding to the hole concentration and electron concentration of the deep ultraviolet light-emitting diode proposed in this invention is shifted 2 nm to the right relative to the horizontal axis of the hole concentration of the standard deep ultraviolet light-emitting diode.

[0047] Figure 6 The graphs show the relationship between external quantum efficiency and current density, and the relationship between optical power and current density in the deep ultraviolet light-emitting diode and Embodiment 1 of the present invention; wherein (a) is the relationship between external quantum efficiency and current density, and (b) is the relationship between optical power and current density.

[0048] Among them, 101 is the substrate, 102 is the n-type semiconductor electron injection layer, 103 is the multi-quantum well active region, 104 is the p-type electron blocking layer, 105 is the p-type AlGaN insertion layer, 106 is the n-type AlGaN insertion layer, 107 is the p-type semiconductor hole injection layer, 108 is the p-type contact layer, 109 is the p-type electrode, and 110 is the n-type electrode. Detailed Implementation

[0049] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. However, this is not the only description; all aspects not described in detail herein are based on conventional techniques in the art.

[0050] Example 1

[0051] A deep ultraviolet light-emitting diode device structure for hole acceleration, such as Figure 1 As shown, from bottom to top, the structure includes a substrate 101, a buffer layer, and an n-type semiconductor electron injection layer 102. On one side of the n-type semiconductor electron injection layer 102, there are sequentially arranged a multi-quantum well active region 103, a p-type AlGaN electron blocking layer 104, a p-type AlGaN insertion layer 105, an n-type AlGaN insertion layer 106, a p-type semiconductor hole injection layer 107, a p-type contact layer 108, and a p-type electrode 109. On the other side of the n-type semiconductor electron injection layer 102, there is an n-type electrode 110.

[0052] The percentage of Al composition in both the p-type AlGaN insertion layer 105 and the n-type AlGaN insertion layer 106 is higher than that in the p-type AlGaN hole injection layer and lower than that in the p-type AlGaN electron blocking layer. The Al composition of the p-type AlGaN insertion layer and the n-type AlGaN insertion layer can be the same or different, as long as their Al composition percentage is guaranteed to be higher than that in the p-type AlGaN hole injection layer and lower than that in the p-type AlGaN electron blocking layer.

[0053] The doping concentration of both the p-type AlGaN insertion layer and the n-type AlGaN insertion layer is 2 × 10⁻⁶. 17 cm -3 The thickness of each is 5nm.

[0054] The substrate is made of sapphire.

[0055] Example 2

[0056] A method for fabricating a deep ultraviolet light-emitting diode device structure to achieve hole acceleration includes the following steps:

[0057] (1) An AlN buffer layer is grown on the surface of a sapphire substrate in the reaction chamber of MOCVD;

[0058] (2) In the MOCVD reaction chamber, an n-type semiconductor electron injection layer is grown on the buffer layer from step (1). The material is AlGaN, and an n-type semiconductor is formed by introducing Si doping. The Al composition of the n-type semiconductor electron injection layer is 60%, and the doping concentration is 8 × 10⁻⁶. 18 cm -3 The thickness is 4μm.

[0059] (3) In the MOCVD reaction chamber, Al is alternately grown on the n-type semiconductor electron injection layer from step (2). m Ga 1-m N-barrier layer and Al n Ga 1-n The N-well layer forms a multi-quantum-well active region, wherein the Al component m in the barrier layer should be greater than the Al component n in the well layer; the Al component percentage in the barrier layer in the active region is 57%, and the Al component percentage in the well layer is 45%.

[0060] (4) In the reaction chamber of MOCVD, an AlGaN electron blocking layer is grown on the multi-quantum well active region composed of a periodic barrier layer and a potential well layer in step (3), and p-type doping is performed by introducing Mg impurities to form a p-type AlGaN electron blocking layer; the Al composition of the p-type AlGaN electron blocking layer is 60%, and the thickness is 10 nm.

[0061] (5) In the reaction chamber of MOCVD, an AlGaN thin layer is grown on the surface of the p-type AlGaN electron blocking layer in step (4), and Mg impurities are introduced for p-type doping to form a p-type AlGaN insertion layer.

[0062] (6) In the reaction chamber of MOCVD, an AlGaN thin layer of the same thickness is grown on the surface of the p-type AlGaN insertion layer obtained in step (4), and Si doping is introduced to perform n-type doping to form an n-type AlGaN insertion layer.

[0063] (7) In the reaction chamber of MOCVD, a p-type AlGaN hole injection layer is grown on the surface of the n-type AlGaN insertion layer obtained in step (6), and p-type doping is performed by introducing Mg impurities; the Al composition of the p-type AlGaN electron blocking layer is 60%, and the thickness is 10 nm.

[0064] (8) In the reaction chamber of MOCVD, a p-type contact layer is grown on the surface of the p-type AlGaN hole injection layer obtained in step (7), the material of which is GaN, and p-type heavy doping is performed by introducing Mg impurities.

[0065] (9) Next, the mesa of the AlGaN-based deep ultraviolet light-emitting diode is etched through photolithography, etching and other steps, and a part of the n-type semiconductor electron injection layer is exposed. Then, the p-type electrode and the n-type electrode are fabricated through photolithography, electron beam evaporation and other processes; the Al composition of the p-type AlGaN hole injection layer is 40%.

[0066] Comparative Example 1

[0067] A standard deep ultraviolet light-emitting diode includes, from bottom to top, a substrate, a buffer layer, and an n-type semiconductor electron injection layer. On one side of the n-type semiconductor electron injection layer, a multi-quantum-well active region, a p-type AlGaN electron blocking layer, a p-type semiconductor hole injection layer, a p-type contact layer, and a p-type electrode are sequentially arranged. On the other side of the n-type semiconductor electron injection layer, an n-type electrode is provided. The difference between Comparative Example 1 and Example 1 is that the p-type AlGaN insertion layer and the n-type AlGaN insertion layer are not provided, but all other aspects are the same.

[0068] Figure 2 The table shows the electric field distribution of Example 1 and a standard deep ultraviolet light-emitting diode (Comparative Example 1) at the partial electron blocking layer and partial hole injection layer. The work done by the electric field on the holes passing through this portion is calculated and displayed in the table, where W0 is the work done by the electric field on the holes in the standard deep ultraviolet light-emitting diode, and W1 is the work done by the electric field on the holes in Example 1. The values ​​of the work done by the electric field show that the holes from the hole injection layer in Example 1 can obtain more kinetic energy (W1 > W0), which is beneficial for more holes to enter the active region, improving the hole injection efficiency and enhancing the photoelectric performance of the deep ultraviolet light-emitting diode.

[0069] Figure 3 In (a), the effective valence band barrier height of holes in the electron blocking layer is ΔΦ. H (471.2 meV), valence band offset ΔE0 (222.6 meV) between electron blocking layer and hole injection layer;

[0070] Figure 3 In (b), the effective valence band barrier height of holes in the electron blocking layer is ΔΦ. H (430.8 meV), the valence band offsets ΔE1 (115.9 meV) and ΔE2 (107.0 meV) between the electron blocking layer and the hole injection layer. From Figure 3 As can be seen from Embodiment 1 of the present invention, ΔΦ H As the voltage decreased from 471.2 meV to 430.8 meV, the valence band offset between the electron blocking layer and the hole injection layer changed from a steep ΔE0 (222.6 meV) to a stepped ΔE1 (115.9 meV) and ΔE2 (107.0 meV), which weakened the blocking effect of the electron blocking layer on hole injection and further improved the hole injection efficiency.

[0071] Figure 4 As can be seen from the data, there is no significant difference in the IV curves of the two devices, indicating that the insertion layer improves the hole injection efficiency without degrading the electrical performance of the devices.

[0072] from Figure 5 It can be seen that in the active region, the hole concentration and electron concentration of this application have been effectively improved.

[0073] from Figure 6 It can be seen that the external quantum efficiency and optical output power of Example 1 have been effectively improved.

[0074] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A deep ultraviolet light-emitting diode device structure for hole acceleration, characterized in that, From bottom to top, it includes a substrate, a buffer layer and an n-type semiconductor electron injection layer. On one side of the n-type semiconductor electron injection layer, there are sequentially a multi-quantum-well active region, a p-type AlGaN electron blocking layer, a p-type AlGaN insertion layer, an n-type AlGaN insertion layer, a p-type AlGaN hole injection layer, a p-type contact layer and a p-type electrode. On the other side of the n-type semiconductor electron injection layer, there is an n-type electrode. The percentage of Al composition in both p-type AlGaN insertion layers and n-type AlGaN insertion layers is higher than that in p-type AlGaN hole injection layers but lower than that in p-type AlGaN electron blocking layers.

2. The deep ultraviolet light-emitting diode device structure for hole acceleration according to claim 1, characterized in that, The doping concentration of both the p-type AlGaN insertion layer and the n-type AlGaN insertion layer is 1 × 10⁻⁶. 17 cm -3 ~ 4 × 10 17 cm -3 The thickness is 2 nm to 10 nm.

3. The deep ultraviolet light-emitting diode device structure for hole acceleration according to claim 2, characterized in that, Both the p-type AlGaN insertion layer and the n-type AlGaN insertion layer have a doping concentration of 2 × 10⁻⁶. 17 cm -3 The thickness of each is 5 nm.

4. The deep ultraviolet light-emitting diode device structure for hole acceleration according to claim 1, characterized in that, The substrate is made of one of the following materials: sapphire, silicon carbide, aluminum nitride, gallium nitride, or silicon.

5. A method for fabricating a deep ultraviolet light-emitting diode device structure for hole acceleration as described in claim 4, characterized in that, The steps include the following: (1) An AlN buffer layer is grown on the surface of a sapphire substrate in the reaction chamber of MOCVD; (2) In the reaction chamber of MOCVD, an n-type semiconductor electron injection layer is grown on the buffer layer of step (1), the material of which is AlGaN, and an n-type semiconductor is formed by introducing Si doping. (3) In the MOCVD reaction chamber, Al is alternately grown on the n-type semiconductor electron injection layer of step (2). m Ga 1-m N-barrier layer and Al n Ga 1-n N potential well layers form a multi-quantum well active region, wherein the Al component m in the barrier layer should be greater than the Al component n in the potential well layer; (4) In the reaction chamber of MOCVD, an AlGaN electron blocking layer is grown on the multi-quantum well active region composed of a periodic barrier layer and a potential well layer in step (3), and a p-type AlGaN electron blocking layer is formed by introducing Mg impurities for p-type doping. (5) In the reaction chamber of MOCVD, an AlGaN thin layer is grown on the surface of the p-type AlGaN electron blocking layer in step (4), and Mg impurities are introduced for p-type doping to form a p-type AlGaN insertion layer. (6) In the reaction chamber of MOCVD, an AlGaN thin layer of the same thickness is grown on the surface of the p-type AlGaN insertion layer obtained in step (4), and Si doping is introduced to perform n-type doping to form an n-type AlGaN insertion layer. (7) In the reaction chamber of MOCVD, a p-type AlGaN hole injection layer is grown on the surface of the n-type AlGaN insertion layer obtained in step (6), and p-type doping is performed by introducing Mg impurities; (8) In the reaction chamber of MOCVD, a p-type contact layer is grown on the surface of the p-type AlGaN hole injection layer obtained in step (7). The material is GaN, and p-type heavy doping is performed by introducing Mg impurities. (9) Next, the mesa of the AlGaN-based deep ultraviolet light-emitting diode is etched through photolithography and etching steps, and a portion of the n-type semiconductor electron injection layer is exposed. Then, the p-type electrode and the n-type electrode are fabricated through photolithography and electron beam evaporation processes.

6. The method for fabricating a deep ultraviolet light-emitting diode device structure for hole acceleration according to claim 5, characterized in that, In the MOCVD growth process, at a growth temperature of 800 °C, trimethylgallium or triethylgallium is used as the gallium source, trimethylaluminum is used as the aluminum source, ammonia is used as the nitrogen source, silane is used as the Si impurity source, and magnesia-dicenocene is used as the Mg impurity source.

7. The method for fabricating a deep ultraviolet light-emitting diode device structure for hole acceleration according to claim 6, characterized in that, In step (2), the Al composition of the AlGaN material in the n-type semiconductor electron injection layer ranges from 0% to 100%, and the doping concentration is 6 × 10⁻⁶. 18 ~ 9×10 18 cm -3 The thickness is 3.5 μm ~ 4.5 μm.

8. The method for fabricating a deep ultraviolet light-emitting diode device structure for hole acceleration according to claim 7, characterized in that, The Al composition of the AlGaN material in the n-type semiconductor electron injection layer is 60%, and the doping concentration is 8 × 10⁻⁶. 18 cm -3 The thickness is 4 μm.

9. The method for fabricating a deep ultraviolet light-emitting diode device structure for hole acceleration according to claim 8, characterized in that, In step (3), the percentage m of Al component in the barrier layer of the active region is 50% ~ 100%, and the percentage of Al component in the well layer is 0% ~ m.

10. The method for fabricating a deep ultraviolet light-emitting diode device structure for hole acceleration according to claim 9, characterized in that, In the active region, the Al component percentage m of the barrier layer is 57%, and the Al component percentage of the well layer is 45%.

11. The method for fabricating a deep ultraviolet light-emitting diode device structure for hole acceleration according to claim 10, characterized in that, In step (4), the Al composition of the p-type AlGaN electron blocking layer is 60% ~ 100%, and the thickness is 5 ~ 10 nm.

12. The method for fabricating a deep ultraviolet light-emitting diode device structure for hole acceleration according to claim 11, characterized in that, The p-type AlGaN electron blocking layer has an Al composition of 60% and a thickness of 10 nm.

13. The method for fabricating a deep ultraviolet light-emitting diode device structure for hole acceleration according to claim 12, characterized in that, In step (7), the thickness of the p-type AlGaN hole injection layer is 45 nm ~ 55 nm, and the doping concentration is 1 × 10⁻⁶. 17 cm -3 ~ 3×10 17 cm -3 .

14. The method for fabricating a deep ultraviolet light-emitting diode device structure for hole acceleration according to claim 13, characterized in that, The thickness of the p-type AlGaN hole injection layer is 50 nm, and the doping concentration is 1×10⁻⁶. 17 cm -3 .

15. The method for fabricating a deep ultraviolet light-emitting diode device structure for hole acceleration as described in claim 14, characterized in that, The Al composition of the p-type AlGaN hole injection layer is 35% to 45%.

Images