Preparation method of gallium oxide ultraviolet detector based on dual-functional self-assembled passivation layer

Abstract

The present invention provides a gallium oxide ultraviolet detector based on a dual-functional self-assembled passivation layer and a preparation method thereof, comprising a substrate layer, an oxidant layer and a dual-functional self-assembled passivation layer arranged from bottom to top, wherein metal electrodes in contact with the gallium oxide layer are arranged on both sides of the dual-functional self-assembled passivation layer, wherein the dual-functional self-assembled passivation layer comprises a first passivation layer and a second passivation layer arranged from bottom to top, wherein the passivation material of the first passivation layer is a material for reducing surface defects of the gallium oxide layer, and the passivation material of the second passivation layer is a material for enhancing the ultraviolet photon absorption rate, and the dual-functional self-assembled passivation layer is formed by combining passivation materials with different functions, and the gallium oxide ultraviolet detector is passivated by using the dual-functional self-assembled passivation layer, thereby improving its performance from the two aspects of reducing surface defects of gallium oxide and enhancing ultraviolet photon absorption.

Description

Technical Field

[0001] The present invention relates to the field of photoelectric detection, and in particular to a method for preparing a gallium oxide ultraviolet detector based on a dual-functional self-assembled passivation layer. Background Art

[0002] The solar-blind ultraviolet detector is an ultraviolet detector based on the 200-280nm solar-blind band. Since the ozone layer completely absorbs the ultraviolet radiation in the 200-280nm solar-blind band, the background radiation of this band in the atmosphere is close to zero, which makes the solar-blind ultraviolet detector have the advantages of low background noise, high sensitivity and strong anti-interference ability. It is widely used in military and civilian fields such as missile early warning, fire monitoring, and atmospheric environment detection, and has important application value and development prospects.

[0003] Gallium oxide (Ga 2 O 3 ) is considered to be an ideal solar-blind UV detector material due to its wide bandgap (4.9eV), high breakdown field strength, high mobility, excellent thermal stability and chemical stability. However, gallium oxide UV detectors also have problems such as low responsivity, low detection efficiency and high dark current. These problems are due to defects that are easily generated during the growth of gallium oxide crystals. On the other hand, the high resistance of gallium oxide itself will also limit the responsivity and detection efficiency of UV detectors. At present, research mainly solves the problems of low responsivity, low detection efficiency and high dark current of gallium oxide UV detectors by optimizing doping materials, optimizing device structure design and optimizing processes.

[0004] As a key process to improve the performance and stability of semiconductor devices, surface passivation technology has recently become an important research technology to improve the performance of gallium oxide ultraviolet detectors and solve the problems of low responsivity, low detection efficiency and high dark current of gallium oxide ultraviolet detectors. In the existing research on the effect of surface passivation technology on the performance of gallium oxide ultraviolet detectors, Al is usually used. 2 O 3 、SiO 2 , β-(Al 0.25 Ga 0.75 ) 2 O 3 Materials such as quartz and argon are used to make a passivation layer with a thickness of 10nm-20nm for surface passivation to reduce surface defects of the gallium oxide film or enhance ultraviolet light absorption to improve the performance of the gallium oxide ultraviolet detector.

[0005] In the surface passivation technology for gallium oxide ultraviolet detectors, although single-layer passivation can partially improve the performance of gallium oxide ultraviolet detectors, it cannot simultaneously solve the problems of gallium oxide surface defects and low ultraviolet photon absorption rate. In addition, the thickness of the single-layer passivation film will also affect the absorption of ultraviolet photons, thereby affecting the performance of gallium oxide ultraviolet detectors. For example, using Al 2 O 3 The surface of the GaO2 UV detector can be passivated by using a single-layer passivation film. Although the surface defects of the GaO2 film can be reduced, the thicker Al 2 O 3 A single-layer passivation film will also reduce the absorption rate of ultraviolet photons by the gallium oxide film, which is not conducive to enhancing the performance of the gallium oxide ultraviolet detector. Therefore, if single-layer passivation is to significantly improve the performance of the gallium oxide ultraviolet detector, it is necessary not only to consider the impact of different passivation layer materials on the gallium oxide film, but also to consider the impact of the thickness of different single-layer passivation films on the detector's ultraviolet photon absorption rate. If a multi-layer composite passivation method of three or more layers is used, although it has the effect of increasing the selectivity of ultraviolet light absorption, the composite of the multi-layer passivation layer will weaken the role of the passivation layer that reduces surface defects, and the composite of the multi-layer passivation layer requires strict control of the thickness of the single-layer passivation layer to avoid the ultraviolet photon absorption rate caused by the superposition of the multi-layer passivation layer. The performance of the gallium oxide ultraviolet detector has not been significantly improved.

[0006] In summary, the current surface passivation technology for gallium oxide ultraviolet detectors is difficult to simultaneously achieve the effects of reducing gallium oxide surface defects and enhancing ultraviolet photon absorption. Summary of the invention

[0007] The purpose of the present invention is to provide a gallium oxide ultraviolet detector based on a dual-functional self-assembled passivation layer and a preparation method thereof. The dual-functional self-assembled passivation layer is formed by combining passivation materials with different functions, and the gallium oxide ultraviolet detector is passivated by using the dual-functional self-assembled passivation layer, so as to improve its performance from two aspects: reducing the surface defects of gallium oxide and enhancing the absorption of ultraviolet photons.

[0008] To achieve the above objectives, the present technical solution provides a method for preparing a gallium oxide ultraviolet detector based on a dual-functional self-assembled passivation layer, comprising the following steps:

[0009] S1: cleaning and drying the substrate material to obtain a substrate layer;

[0010] S2: growing a gallium oxide layer on the substrate layer;

[0011] S3: growing a first passivation layer on the gallium oxide layer, wherein the passivation material of the first passivation layer is a material that reduces the effect of surface defects of the gallium oxide layer;

[0012] S4: growing a second passivation layer on the first passivation layer to form a dual-functional self-assembled passivation layer, wherein the passivation material of the second passivation layer is a material that enhances the ultraviolet photon absorption rate;

[0013] S5: photolithography electrode patterns on both sides of the dual-functional self-assembled passivation layer, and deposition of laminated metal to form metal electrodes;

[0014] S6: Anneal the metal electrode to form an ohmic contact.

[0015] The present invention provides a gallium oxide ultraviolet detector based on a dual-functional self-assembled passivation layer, comprising a substrate layer, a gallium oxide layer and a dual-functional self-assembled passivation layer arranged from bottom to top, wherein metal electrodes in contact with the gallium oxide layer are arranged on both sides of the dual-functional self-assembled passivation layer, wherein the dual-functional self-assembled passivation layer comprises a first passivation layer and a second passivation layer arranged from bottom to top, wherein the passivation material of the first passivation layer is a material for reducing surface defects of the gallium oxide layer, and the passivation material of the second passivation layer is a material for enhancing the ultraviolet photon absorption rate.

[0016] Compared with the prior art, this technical solution has the following characteristics and beneficial effects:

[0017] The preparation method of the gallium oxide ultraviolet detector based on the dual-functional self-assembled passivation layer provided in the present scheme has a simple manufacturing process. The dual-functional self-assembled passivation layer combines passivation layer materials with two different functions, which can not only reduce the surface defects of the gallium oxide film, reduce the recombination of photogenerated carriers, and change the carrier transport pathway, thereby improving the carrier transport efficiency. It can also play a buffering role at the interface, enhance the photoelectric response, improve the electrical isolation effect, and enhance the performance of the gallium oxide photodetector. At the same time, the dual-functional self-assembled passivation layer can also protect the gallium oxide layer, avoid damage to the gallium oxide layer during subsequent manufacturing and use, and enhance long-term stability. The present invention solves the problems of the low responsivity and detection efficiency of the current gallium oxide ultraviolet detector, and the limited improvement of its performance by single-layer passivation technology, and provides new ideas and methods for optimizing the performance of gallium oxide ultraviolet detectors. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic diagram of growing a gallium oxide layer on a substrate layer according to an embodiment of the present invention.

[0019] Figure 2 It is a schematic diagram of the structure of growing a first passivation layer on a gallium oxide layer according to an embodiment of the present invention.

[0020] Figure 3 It is a schematic structural diagram of growing a second passivation layer on a first passivation layer according to an embodiment of the present invention.

[0021] Figure 4is a schematic structural diagram of a deposited metal electrode according to an embodiment of the present invention.

[0022] Figure 5 This is a performance test example of Comparative Example 1 and Example 1. DETAILED DESCRIPTION

[0023] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0024] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0025] In order to solve the problems of low responsivity and detection efficiency of the current gallium oxide ultraviolet detector and limited improvement of its performance by single-layer passivation technology, this scheme provides a method for preparing a gallium oxide ultraviolet detector based on a dual-functional self-assembled passivation layer, comprising the following steps:

[0026] S1: cleaning and drying the substrate material to obtain a substrate layer;

[0027] S2: growing a gallium oxide layer on the substrate layer;

[0028] S3: growing a first passivation layer on the gallium oxide layer, wherein the passivation material of the first passivation layer is a material that reduces the effect of surface defects of the gallium oxide layer;

[0029] S4: growing a second passivation layer on the first passivation layer to form a dual-functional self-assembled passivation layer, wherein the passivation material of the second passivation layer is a material that enhances the ultraviolet photon absorption rate;

[0030] S5: photolithography electrode patterns on both sides of the dual-functional self-assembled passivation layer, and deposition of laminated metal to form metal electrodes;

[0031] S6: Anneal the metal electrode to form an ohmic contact.

[0032] The gallium oxide ultraviolet detector based on the dual-functional self-assembled passivation layer provided in the present invention is obtained by combining passivation materials with two different functions of reducing surface defects and enhancing light absorption to obtain a dual-functional self-assembled passivation layer. The gallium oxide ultraviolet detector is passivated by using the dual-functional self-assembled passivation layer to reduce the surface defects of gallium oxide while enhancing the ultraviolet photon absorption rate of the gallium oxide layer, thereby comprehensively improving the light response performance of the gallium oxide ultraviolet detector.

[0033] In step S1, the substrate material is selected from single crystal Ga 2 O 3 , Sapphire Al 2 O 3 , AlN, quartz, single crystal silicon or any combination thereof, and the substrate material is cleaned and dried to obtain the substrate layer. The substrate material of the substrate layer of the present solution has good adaptability and compatibility with the gallium oxide layer.

[0034] In some embodiments, the substrate layer is ultrasonically cleaned with acetone, isopropanol and deionized water for 3 to 8 minutes, and then dried with a nitrogen gun to obtain the substrate layer. Preferably, the substrate layer is ultrasonically cleaned with acetone, isopropanol and deionized water for 5 minutes. This solution uses acetone, isopropanol and deionized water to ultrasonically clean the substrate material, which can effectively remove organic impurities that may exist on the surface of the substrate, such as oil stains, fingerprint residues, etc. These organic impurities may interfere with the growth process of the gallium oxide layer and affect its crystallization quality and electrical properties. Removing them by cleaning can ensure a good interface bonding between the gallium oxide layer and the substrate layer, which is beneficial to the growth and performance of subsequent layers; and the high-frequency vibration generated during the ultrasonic cleaning process can detach the particulate impurities (such as dust, debris, etc.) attached to the surface of the substrate, and combined with the flushing effect of the cleaning agent, these particulate impurities can be completely removed.

[0035] In some embodiments, the substrate layer is ultrasonically cleaned with acetone, isopropanol and deionized water for 3 to 8 minutes, cleaned with an organic piranha solution for 25 to 40 minutes, and dried with a nitrogen gun to obtain the substrate layer, wherein the piranha solution is a mixed solution of concentrated sulfuric acid and peroxygen water in a ratio of 3:1. Preferably, the piranha solution is used for cleaning for 30 minutes, which has the advantage of cleaning the dangling bonds, surface states and stubborn contamination on the surface of the substrate layer.

[0036] like Figure 1 As shown, in step S2, a gallium oxide layer is grown on the substrate layer by using any one of molecular beam epitaxy (MBE), metal organic chemical vapor deposition (MOCVD), pulsed laser deposition (PLD), atomic layer deposition (ALD), radio frequency magnetron sputtering (RFMS), mist chemical vapor deposition (Mist-CVD), and halide vapor phase epitaxy (HVPE).

[0037] In some embodiments, the material for growing the gallium oxide layer is selected from one or any combination of amorphous gallium oxide, polycrystalline gallium oxide or single crystal gallium oxide, wherein amorphous gallium oxide has a unique disordered structure. This structural feature makes it easier for amorphous gallium oxide to achieve large-area uniform deposition of thin films in some detector applications that require flexibility or large-area preparation, and its flexible properties help to adapt to the needs of devices with different shapes and curved surfaces, expanding the application range of detectors, such as ultraviolet detection in flexible electronic devices; polycrystalline gallium oxide is composed of multiple small grains, which is relatively easy to prepare and low in cost. In some application scenarios that are more sensitive to cost and do not have extremely stringent performance requirements, polycrystalline gallium oxide can provide a cost-effective solution; single crystal gallium oxide has a highly ordered crystal structure. This structural feature enables single crystal gallium oxide to provide better detection sensitivity, response speed and stability in high-end application fields that require high detector performance.

[0038] like Figure 2 As shown, a first passivation layer is grown on the gallium oxide layer. In some embodiments, in step S3, the passivation material of the first passivation layer is selected from HfO 2 , Si 3 N 4 , TiO 2 , AlN or Al 2 O 3 One or any combination of these materials are materials that have the effect of reducing surface defects of the gallium oxide layer.

[0039] Specifically, the passivation material of the first passivation layer of the present invention can form a good chemical bond with the surface atoms of the gallium oxide layer during deposition. For example, there is a chemical affinity between AlN and gallium oxide, which can closely adhere to the surface of gallium oxide, fill the surface atomic vacancies and irregularities, and effectively reduce the number of dangling bonds and surface states on the surface of gallium oxide. In addition, the first passivation layer can also be used as a diffusion barrier layer or a repair layer, such as TiO 2 The high chemical stability of gallium oxide can prevent impurity atoms (oxygen vacancies, metal impurities, etc.) from diffusing into the gallium oxide layer.

[0040] In some embodiments, the method of growing the first passivation layer in step S3 is selected from one or any combination of atomic layer deposition (ALD) technology, plasma enhanced chemical vapor deposition (PECVD) technology, and magnetron sputtering.

[0041] In some embodiments, the thickness of the first passivation layer is between 5nm and 50nm, preferably between 5nm and 10nm. And in some embodiments, the surface roughness of the first passivation layer needs to be as small as possible. The appropriate thickness range helps to achieve better results in reducing surface defects of the gallium oxide layer. Too thick may affect the subsequent layer growth and overall performance, and too thin may not fully exert the passivation effect; and a smaller surface roughness can further optimize the interface quality between the gallium oxide layer and the first passivation layer, reduce interface scattering and defects, promote more efficient carrier transmission, and improve the detector response speed and sensitivity. At the same time, it is conducive to the uniform growth of the subsequent second passivation layer, ensuring the structural integrity and synergistic function of the double-layer passivation layer, thereby enhancing the overall performance and stability of the detector.

[0042] like Figure 3 As shown, a second passivation layer is grown on the first passivation layer. In some embodiments, in step S4, the passivation material of the second passivation layer is selected from Ti 3 C 2 , AZO, SnO 2 , CdTe, ITO or ZrO 2 One or any combination of these passivation materials are materials that have the function of enhancing the ultraviolet photon absorption rate.

[0043] Specifically, the passivation material of the second passivation layer has a unique energy band structure and can absorb ultraviolet light in a wider wavelength range. For example, Ti 3 C 2 As an emerging two-dimensional material, its energy band structure enables it to exhibit strong light absorption ability in a specific ultraviolet band, which complements the absorption band of the gallium oxide layer itself, thereby broadening the absorption spectrum range of the entire detector to ultraviolet light; and when different passivation material combinations are selected, the absorption characteristics of different passivation materials at different ultraviolet wavelengths are superimposed on each other, further enhancing the overall light absorption effect. For example, AZO has better absorption in a certain band, while SnO 2 One has advantages in another wavelength band, and their combined use can achieve efficient absorption in a wider wavelength range.

[0044] In addition, the passivation material of the second passivation layer has suitable optical constants such as refractive index, which can reduce the reflection and scattering loss of ultraviolet light at the interface between the passivation layer and the gallium oxide layer and inside the passivation layer, so that more ultraviolet photons can enter the gallium oxide layer and be absorbed and converted into carriers. After absorbing ultraviolet photons, some materials (such as CdTe) have a higher efficiency of photogenerated carrier generation and can more effectively convert photon energy into electron-hole pairs.

[0045] In some embodiments, the method of growing the second passivation layer in step S4 is selected from one or any combination of atomic layer deposition (ALD) technology, plasma enhanced chemical vapor deposition (PECVD) technology, and magnetron sputtering.

[0046] In some embodiments, the thickness of the second passivation layer is between 5nm and 50nm, preferably between 5nm and 10nm. And in some embodiments, the surface roughness of the second passivation layer needs to be as small as possible. The thickness of the second passivation layer between 5nm and 50nm can achieve better results in enhancing the absorption of ultraviolet photons. This thickness range can effectively couple the electronic state in the passivation material with the energy of the incident ultraviolet photons, ensure sufficient interaction volume to absorb photons, and avoid the problem of light absorption saturation or internal scattering enhancement caused by excessive thickness; and the appropriate thickness of the second passivation layer together with the gallium oxide layer and the first passivation layer constitute an optimized photoelectric conversion structure. This thickness range ensures that the second passivation layer maximizes the light absorption enhancement effect without interfering with the functions of other layers, and promotes the effective transmission of photogenerated carriers between layers.

[0047] like Figure 4 As shown, in step S5, a stacked metal is deposited by electron beam evaporation, thermal evaporation or magnetron sputtering to form a metal electrode.

[0048] In some embodiments, the metal material of the metal electrode is one or more combinations of metals such as Ti, Al, Ni, Au, Mo, and Pt.

[0049] In some embodiments, in step S6, a rapid thermal annealing device (RTP) or a tubular annealing furnace is used to anneal the metal electrode, and the metal electrode needs to form an ohmic contact with the gallium oxide layer. In a specific embodiment, the RTP method is used to anneal the ohmic contact, and the specific annealing conditions are: in a nitrogen atmosphere, the annealing temperature is 470 ° C, and the annealing is performed for 1 min.

[0050] On the other hand, the present scheme provides a gallium oxide ultraviolet detector based on a dual-functional self-assembled passivation layer prepared according to the above-mentioned method for preparing a gallium oxide ultraviolet detector based on a dual-functional self-assembled passivation layer, comprising: a substrate layer, an oxidant layer and a dual-functional self-assembled passivation layer arranged from bottom to top, metal electrodes in contact with the gallium oxide layer are arranged on both sides of the dual-functional self-assembled passivation layer, wherein the dual-functional self-assembled passivation layer comprises a first passivation layer and a second passivation layer arranged from bottom to top, wherein the passivation material of the first passivation layer is a material for reducing surface defects of the gallium oxide layer, and the passivation material of the second passivation layer is a material for enhancing the ultraviolet photon absorption rate.

[0051] In this solution, the gallium oxide layer contacts the substrate layer, the first passivation layer contacts the gallium oxide layer, the second passivation layer contacts the first passivation layer, the bottom of the metal electrode contacts the gallium oxide layer, and the side of the metal electrode contacts the bifunctional self-assembled passivation layer.

[0052] As mentioned above, since the above-mentioned gallium oxide ultraviolet detector based on the dual-functional self-assembled passivation layer provided by the present solution has a dual-functional self-assembled passivation layer composed of different passivation materials, by combining passivation materials with two different functions of reducing surface defects and enhancing light absorption, the ultraviolet photon absorption rate of the gallium oxide layer is enhanced while reducing the surface defects of gallium oxide, thereby comprehensively improving the light response performance of the gallium oxide ultraviolet detector. Through the design of the dual-functional self-assembled passivation layer, the function of reducing surface defects or enhancing ultraviolet photon absorption rate of each passivation layer is further enhanced, which can effectively solve the problems of reduced responsiveness and detection efficiency of gallium oxide ultraviolet detectors from multiple aspects. Compared with single-layer passivation and multi-layer composite passivation technology, the performance of gallium oxide ultraviolet detectors is further optimized, and it has broad application prospects.

[0053] In order to verify that the gallium oxide ultraviolet detector based on the dual-functional self-assembled passivation layer prepared by this scheme has both the functions of reducing surface defects and enhancing light absorption, this scheme designed the following specific embodiments and tested their performance:

[0054] Embodiment 1:

[0055] The Si substrate with a thickness of 100 nm was cleaned with propanol, isopropanol and deionized water for 5 minutes each, and then dried with nitrogen to obtain a clean substrate layer; GaO2 with a thickness of 100 nm was deposited on the substrate using metal organic chemical vapor deposition (MOCVD) technology. 2 O 3 layer; through atomic layer deposition (ALD) technology, on Ga 2 O 3 TiO with a thickness of 10 nm was deposited on the surface of the layer. 2 The first passivation layer ensures a smooth surface to reduce interface scattering and defects, improve carrier transfer efficiency, and provide a high-quality foundation for the uniform growth of the subsequent second passivation layer; plasma enhanced chemical vapor deposition (PECVD) technology is used to deposit a 10 nm thick CdTe second passivation layer on the first passivation layer. CdTe has excellent ultraviolet photon absorption performance and high photogenerated carrier generation efficiency, and can effectively convert light energy into electron-hole pairs; electrode patterns are made on the substrate layer using photolithography technology, and Ti and Au stacked metals are deposited in sequence by electron beam evaporation. The thickness of the metal layers is 20 nm and 80 nm, respectively. After the lift-off process, metal electrodes are formed. Subsequently, rapid thermal annealing (RTP) technology is used to anneal at 470°C for 1 minute in a nitrogen atmosphere to make the stacked metal electrodes bonded to Ga2 O 3 The layers form a good ohmic contact.

[0056] Comparative Example 1: Gallium Oxide UV Detector with Conventional Metal-Oxide-Metal Structure

[0057] The Si substrate with a thickness of 100 nm was cleaned with propanol, isopropanol and deionized water for 5 minutes each, and then dried with nitrogen to obtain a clean substrate layer; GaO2 with a thickness of 100 nm was deposited on the substrate using metal organic chemical vapor deposition (MOCVD) technology. 2 O 3 layer; electrode patterns were made on the substrate layer using photolithography technology, and Ti and Au stacked metals were deposited in sequence by electron beam evaporation, with metal layer thicknesses of 20 nm and 80 nm respectively. After a lift-off process, metal electrodes were formed. Subsequently, rapid thermal annealing (RTP) technology was used to anneal at 470 ° C for 1 minute in a nitrogen atmosphere to bond the stacked metal electrodes to the Ga 2 O 3 The layers form a good ohmic contact.

[0058] The difference between Comparative Example 1 and Example 1 is that the conventional gallium oxide ultraviolet detector with a metal-oxide-metal structure provided in Comparative Example 1 does not have a dual-functional self-assembled passivation layer structure.

[0059] Test example 1:

[0060] Under no light conditions, the detectors prepared in Example 1 and Comparative Example 1 were placed in a dark room for dark current testing. Subsequently, the UV light source was adjusted to a wavelength of 250 nm, the light intensity was set to 1 μW / cm², and the light source was aimed at the detector to start testing the IV curve. Starting from zero bias, the forward and reverse bias were gradually increased, and the current value corresponding to each bias point was recorded. The test process was repeated until the preset maximum bias range was reached, complete test data was obtained, and the IV curve was plotted. During the test, it was necessary to ensure that the UV light source was stable and without fluctuations. The IV curves of Example 1 / Comparative Example 1 in dark / light environments are as follows: Figure 5 , wherein the conventional metal-oxidant-metal structure corresponds to Example 1, and the metal-oxide-metal-bifunctional self-assembled passivation layer structure corresponds to Example 1. Figure 5 The results show that the gallium oxide ultraviolet detector based on the dual-functional self-assembled passivation layer in Example 1 exhibits a more significant light-to-dark current ratio and has excellent detection performance in a weak light environment.

[0061] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0062] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. A method for preparing a gallium oxide ultraviolet detector based on a dual-functional self-assembled passivation layer, characterized in that: The following steps are involved: S1: cleaning and drying the substrate material to obtain a substrate layer; S2: growing a gallium oxide layer on the substrate layer; S3: growing a first passivation layer on the gallium oxide layer, wherein the passivation material of the first passivation layer is a material that reduces the surface defects of the gallium oxide layer, the passivation material of the first passivation layer is selected from one or any combination of HfO2, Si3N4, TiO2, AlN or Al2O3, and the thickness of the first passivation layer is between 5nm and 50nm; S4: growing a second passivation layer on the first passivation layer to form a dual-functional self-assembled passivation layer, wherein the passivation material of the second passivation layer is a material that enhances the ultraviolet photon absorption rate, and the passivation material of the second passivation layer is selected from one or any combination of Ti3C2, AZO, SnO2, CdTe, ITO or ZrO2, and the thickness of the second passivation layer is between 5nm and 50nm; S5: photolithography electrode patterns on both sides of the dual-functional self-assembled passivation layer, and deposition of laminated metal to form metal electrodes; S6: Anneal the metal electrode to form an ohmic contact.

2. The method for preparing a gallium oxide ultraviolet detector based on a dual-functional self-assembled passivation layer according to claim 1, characterized in that: The substrate material is selected from one or any combination of single crystal Ga2O3, sapphire Al2O3, AlN, quartz, and single crystal silicon.

3. The method for preparing a gallium oxide ultraviolet detector based on a dual-functional self-assembled passivation layer according to claim 1, characterized in that: The material for growing the gallium oxide layer is selected from one or any combination of amorphous gallium oxide, polycrystalline gallium oxide or single crystal gallium oxide.

4. A gallium oxide ultraviolet detector based on a dual-functional self-assembled passivation layer, characterized in that: include: A substrate layer, a gallium oxide layer and a bifunctional self-assembled passivation layer are arranged from bottom to top, and metal electrodes in contact with the gallium oxide layer are arranged on both sides of the bifunctional self-assembled passivation layer, wherein the bifunctional self-assembled passivation layer includes a first passivation layer and a second passivation layer arranged from bottom to top, wherein the passivation material of the first passivation layer is a material for reducing surface defects of the gallium oxide layer, and the passivation material of the second passivation layer is a material for enhancing the ultraviolet photon absorption rate, wherein the passivation material of the first passivation layer is selected from one or any combination of HfO2, Si3N4, TiO2, AlN or Al2O3; the passivation material of the second passivation layer is selected from one or any combination of Ti3C2, AZO, SnO2, CdTe, ITO or ZrO2, the thickness of the first passivation layer is between 5nm-50nm, and the thickness of the second passivation layer is between 5nm-50nm.

5. The gallium oxide ultraviolet detector based on a dual-functional self-assembled passivation layer according to claim 4, characterized in that: The gallium oxide layer contacts the substrate layer, the first passivation layer contacts the gallium oxide layer, the second passivation layer contacts the first passivation layer, the bottom of the metal electrode contacts the gallium oxide layer, and the side of the metal electrode contacts the bifunctional self-assembled passivation layer.

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