Nitride nanoparticle array growth method, application and photoelectric detector

Abstract

The invention relates to the technical field of nitride nano particle preparation, and provides a nitride nano particle array growth method and application, and a photoelectric detector. According to the method, dangling bonds are provided by utilizing boundary defects of the two-dimensional material etching pattern, nitride nanoparticles have relatively low nucleation energy barriers at the positions, and the two-dimensional material pattern with a nano size can ensure that metal atoms and nitrogen atoms reach the boundary of the two-dimensional material etching pattern within an effective migration length; further, controllable preparation of the nitride nanoparticles is realized; on the structure of the photoelectric detector, a two-dimensional material-nitride Van der Waals heterojunction with a vertical structure is designed, and metal electrodes are located on the two materials respectively; the Van der Waals heterojunction electric field can realize automatic separation and collection of photo-generated charges, can work under zero bias voltage, and has self-driven light response capability. The growth method of the nitride nanoparticle array provides an effective way for preparation of a high-integration, high-sensitivity and self-driven photoelectric detector.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of nitride nanoparticles, and particularly to a method for growing a nitride nanoparticle array and its application, and a photodetector. Background Art

[0002] Due to its matched direct optical bandgap width, nitride materials exhibit great application potential in the field of solar-blind ultraviolet light detection. In addition, nitride has strong anti-irradiation ability and chemical / thermal stability, and the corresponding photodetector can work in a variety of complex and harsh environments. However, limited by the migration rate and effective migration length of photo-generated carriers in nitride materials, the spacing between device metal electrodes and the effective photosensitive area are usually small; at the same time, the photoelectric detection gain that photo-generated charges can achieve within their effective carrier lifetime is still low, which limits the response ability of nitride-based photodetectors.

[0003] For the preparation of multiple nitride-based photodetector pixels and their arrays, in order to avoid crosstalk, it is usually necessary to etch and separate the complete nitride epitaxial layer to form an independent unit structure; however, the mainstream dry etching technology is prone to form a large number of dangling bonds and water oxygen adsorption on the nitride etching sidewalls, which serve as photo-generated charge recombination centers and further restrict the response characteristics of the photodetector. On the other hand, the current lithography + etching technology is carried out on bulk nitride materials, and it is difficult to fabricate device units at the nanoscale, which is not conducive to improving the integration and resolution of the detection imaging system. Low-dimensional nitride materials, such as nitride nanoparticles, with smaller geometric sizes can greatly reduce the pixel size of the photodetector and achieve higher-density integration; at the same time, the large specific surface area of nitride nanoparticles can effectively promote photon absorption and utilization and improve the detector response characteristics. The nitride nanoparticle growth methods reported currently have a random distribution on the substrate and cannot achieve precise control of the growth sites at the nanoscale; they are not suitable for the preparation of regular device pixel arrays and subsequent photoelectric detection imaging applications. Therefore, how to achieve the controllable growth of nitride nanoparticle arrays is the key to realizing their photoelectric detection imaging applications.

[0004] Based on the defects existing in the current nitride nanoparticle growth methods, it is necessary to improve them. Summary of the Invention

[0005] In view of this, the present invention provides a method for growing a nitride nanoparticle array and its application, as well as a photodetector. The present invention provides a method for growing a nitride nanoparticle array and an imaging application of a photodetector based on the nitride nanoparticle array. The core is to utilize the dangling bonds generated at the etched edges of the two-dimensional material nanogratings as the nucleation sites for the nitride nanoparticles to achieve the controllable nucleation growth of the array; meanwhile, a self-powered photodetector structure based on a two-dimensional material-nitride van der Waals heterojunction is designed to meet the requirements of high-sensitivity photodetection imaging applications.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a method for growing a nitride nanoparticle array, including the following steps: Growing an n-type doped nitride epitaxial layer on a substrate surface; Growing a two-dimensional material layer on the n-type doped nitride epitaxial layer; Performing nanograting processing on the two-dimensional material layer to form a two-dimensional material layer with a nanograting arrangement; Growing nitride nanoparticles at the edges of the two-dimensional material layer with a nanograting arrangement.

[0007] Preferably, performing nanograting processing on the two-dimensional material layer to form a two-dimensional material layer with a nanograting arrangement includes: Using nanoimprinting to form a nanosized photoresist pattern mask, and combining reactive ion etching to transfer the pattern to the two-dimensional material layer to form a two-dimensional material layer with a nanograting arrangement; Or, performing nanograting processing on the two-dimensional material layer to form a two-dimensional material layer with a nanograting arrangement includes: Based on two-beam interference holographic exposure, forming a nanosized pattern array on the photoresist, and then using plasma etching to transfer the pattern to the two-dimensional material layer to form a two-dimensional material layer with a nanograting arrangement.

[0008] Preferably, the nitride nanoparticles are GaN nanoparticles; Growing nitride nanoparticles at the edges of the two-dimensional material layer with a nanograting arrangement specifically includes: Placing the substrate with the two-dimensional material layer having a nanograting arrangement in a reaction chamber, first introducing a TMGa source into the reaction chamber to form Ga metal droplets and adsorb them to the edges of the two-dimensional material layer with a nanograting arrangement, and after closing the TMGa source, then introducing NH 3 Performing a chemical reaction to form a GaN nanoparticle array at the edges of the two-dimensional material layer with a nanograting arrangement.

[0009] Preferably, the n-type doped nitride epitaxial layer is n-Al x Ga 1-xN layers, where 0.15 ≥ x ≥ 0.35; The n-Al x Ga 1-x The thickness of the N layer is 450 - 550 nm.

[0010] Preferably, the two-dimensional material layer includes any one of a graphene layer, a boron nitride layer, and a transition metal dichalcogenide layer.

[0011] Preferably, the n-Al x Ga 1-x The preparation method of the N layer includes: The n-Al x Ga 1-x N layer is prepared by metal-organic chemical vapor deposition, using TMAl, TMGa, and NH 3 as the Al source, Ga source, and N source respectively, and SiH 4 as the doping source, with a growth temperature of 1100 - 1200 °C.

[0012] Preferably, the preparation method of the graphene layer includes: The graphene layer is prepared by ultra-high temperature chemical vapor deposition, using CH 4 , H 2 , and N 2 as the C source, reducing gas, and carrier gas respectively, with a growth temperature of 1150 - 1200 °C, and the flow ratio of CH 4 , H 2 , and N 2 being (1 - 2):(10 - 20):(100 - 120).

[0013] In a second aspect, the present invention also provides an application of the nitride nanoparticle array prepared by the described preparation method in the preparation of a photodetector.

[0014] In a third aspect, the present invention also provides a photodetector, and its preparation method includes the following steps: Prepare nitride nanoparticles to grow on the edge of the two-dimensional material layer arranged in a nanoarray according to the described method; Prepare a first electrode on the surface of the two-dimensional material layer arranged in a nanoarray; Prepare a second electrode on the n-type doped nitride epitaxial layer and between any two adjacent two-dimensional material layers arranged in a nanoarray.

[0015] Preferably, the material of the first electrode includes at least one of Pt, Ti, Ni, and Al; The material of the second electrode includes at least one of Ni, Pt, and Au; The thickness of the first electrode is 30 - 100 nm; The thickness of the second electrode is 30 to 100 nm.

[0016] The method for growing nitride nanoparticle arrays, applications thereof, and photodetectors of the present invention have the following beneficial effects compared with the prior art: 1. In the method for growing nitride nanoparticle arrays of the present invention, the boundary defects of the etched pattern of the two-dimensional material are used to provide dangling bonds. The nitride nanoparticles have a lower nucleation energy barrier at these positions, and the two-dimensional material pattern with a nanoscale size can ensure that metal atoms and nitrogen atoms reach the boundary of the two-dimensional material etched pattern within an effective migration length, thereby realizing the controllable preparation of nitride nanoparticles; 2. In the photodetector of the present invention, a first electrode is prepared on the surface of the two-dimensional material layer arranged in a nanoarray; a second electrode is prepared between any two adjacent two-dimensional material layers arranged in a nanoarray; each regularly arranged group of nitride nanoparticles can act as a single pixel of the photodetector. Therefore, its high-density array can realize high-integration photodetector imaging applications; in the photodetector structure, a two-dimensional material-nitride van der Waals heterojunction with a vertical structure is designed, and the metal electrodes are respectively located on these two materials; the built-in electric field of the van der Waals heterojunction can realize the automatic separation and collection of photo-generated charges and can work under zero bias voltage, having a self-driven light response ability. The method for growing nitride nanoparticle arrays provides an effective way for the preparation of high-integration, high-sensitivity, and self-driven photodetectors. The photodetector array prepared based on this method will play an important role in harsh / unmanned environments such as fire warning and deep space exploration. The photodetector of the present invention is used for imaging, and the controllable accuracy of the nitride nanoparticle array is at the nanoscale. Therefore, in the imaging application of the photodetector, the product has high integration and high imaging resolution. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a schematic flow chart of the method for growing nitride nanoparticle arrays of the present invention; Figure 2 It is a schematic structural diagram of the photodetector of the present invention; Figure 3 It is an I-V characteristic curve diagram of the photodetector in the light state and the dark state in Embodiment 2. Detailed Embodiments

[0019] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0020] It should be noted that similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0021] In the description of the present invention, it should be understood that the relationships indicating directions or positions such as "upper" are based on the directions or positions shown in the drawings, or the directions or positions in which the invention product is usually placed during use, or the directions or positions commonly understood by those skilled in the art. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be construed as a limitation of the present invention.

[0022] The following will be described in detail respectively. It should be noted that the description order of the following embodiments does not limit the preferred order of the embodiments. In addition, in the description of the present application, the term "comprising" means "including but not limited to". The various embodiments of the present invention may exist in a range form; it should be understood that the description in a range form is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of the present invention; therefore, it should be considered that the described range description has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and individual numbers within the counted range, such as 1, 2, 3, 4, 5, and 6, which applies regardless of the range. In addition, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0023] The present invention provides a method for growing a nitride nanoparticle array, comprising the following steps: S1. Growing an n-type doped nitride epitaxial layer on the surface of a substrate; S2. Growing a two-dimensional material layer on the n-type doped nitride epitaxial layer; S3. Performing nano-patterning on the two-dimensional material layer to form a two-dimensional material layer arranged in a nano-array; S4. Growing nitride nanoparticles at the edge of the two-dimensional material layer arranged in a nano-array.

[0024] The method for growing nitride nanoparticle arrays of the present invention includes the following steps: As Figure 1 shown in (a), a substrate 1 is provided; As Figure 1 shown in (b), an n-type doped nitride epitaxial layer 2 is grown on the surface of the substrate 1; As Figure 1 shown in (c), a two-dimensional material layer 3 is grown on the n-type doped nitride epitaxial layer 2; As Figure 1 shown in (d), the two-dimensional material layer is subjected to nano-patterning to form a two-dimensional material layer with a nanoarray arrangement; As Figure 1 shown in (e), nitride nanoparticles 4 are grown on the edge of the two-dimensional material layer with a nanoarray arrangement; The core of the present invention is to utilize the dangling bonds generated at the etched edge of the two-dimensional material nano-pattern as the nucleation sites of the nitride nanoparticles to achieve the controllable nucleation growth of their arrays.

[0025] In some embodiments, based on nano-processing technology, the complete two-dimensional material layer is processed into a nano-sized pattern array, and dangling bonds are formed at the edges of the two-dimensional material layer patterns during the processing; Two processing methods are provided; The first one: The nano-patterning of the two-dimensional material layer to form a two-dimensional material layer with a nanoarray arrangement includes: Using nanoimprinting to form a nano-sized photoresist film pattern mask, combined with reactive ion etching, to transfer the pattern to the two-dimensional material layer to form a two-dimensional material layer with a nanoarray arrangement; The second one: The nano-patterning of the two-dimensional material layer to form a two-dimensional material layer with a nanoarray arrangement includes: Based on double-beam interference holographic exposure, a nano-sized pattern array is formed on the photoresist film, and then the pattern is transferred to the two-dimensional material layer by plasma etching (the two-dimensional array can be achieved by double exposure) to form a two-dimensional material layer with a nanoarray arrangement.

[0026] Specifically, the combination of nanoimprinting and reactive ion etching is an important technical combination in the field of micro-nano processing for patterning the surface of materials; Its basic principle is described as follows: Principle of nanoimprinting: Based on physical imprinting, a nano-scale pattern template is used to imprint the pattern onto the polymer photoresist film on the surface of the two-dimensional material layer under certain temperature and pressure, so that the photoresist film undergoes plastic deformation to form a three-dimensional nano-sized photoresist film pattern mask; Principle of reactive ion etching: In a vacuum chamber, a specific reaction gas is introduced, ionized by a radio frequency electric field to form a plasma, the plasma reacts with the surface of the substrate material, and the products are removed by ion bombardment, and the pattern of the photoresist film is transferred to the substrate material under the protection of the photoresist film mask. The process flow of the combination of nanoimprinting and reactive ion etching is as follows: 1. Template preparation: Using materials such as silicon and quartz, a nano-pattern template is fabricated by electron beam lithography and other technologies; 2. Coating photoresist: A photoresist such as polymethyl methacrylate is spin-coated on the surface of the two-dimensional material layer to control the thickness; 3. Alignment and imprinting: The template is precisely aligned with the two-dimensional material layer coated with glue, and imprinting is carried out under appropriate temperature and pressure to deform the photoresist and replicate the pattern; 4. Demolding: After cooling, the template is separated, and the photoresist (such as polymethyl methacrylate (PMMA), etc.) forms a nano-sized pattern; 5. Preparation of etching equipment: The material layer is placed in the vacuum chamber of the etching equipment, and the equipment is inspected and debugged; 6. Introducing etching gas: Select appropriate gas according to the material (for graphene, a mixed gas of oxygen, argon, etc. can be used; for transition metal chalcogenides, a fluorine-containing gas (such as carbon tetrafluoride) can be used), and precisely control the flow rate; 7. Etching process: Turn on the radio frequency power supply to form plasma, control relevant parameters to etch the two-dimensional material, transfer the pattern, reach the predetermined depth, stop gas supply, and turn off the power supply; 8. Post-treatment: Remove the photoresist by methods such as dissolving with a solvent (such as acetone) or plasma ashing to expose the nano-sized pattern array.

[0027] In some embodiments, based on double-beam interference holographic exposure, a nano-sized pattern array is formed on the film, and then the pattern is transferred to the two-dimensional material layer by plasma etching to form a two-dimensional material layer with a nano-array arrangement. The main steps include: 1. Photoresist coating: Select a photoresist according to the characteristics of the two-dimensional material, spin-coat it on a spin coater, and control the thickness; soft bake on a hot plate at 90 - 120 °C for 1 - 2 minutes; 2. Double-beam interference holographic exposure: Build an interference optical path using ultraviolet laser; set the exposure dose and time according to the characteristics of the photoresist and the pattern requirements, and expose the photoresist; the two-dimensional array pattern requires two exposures in the vertical direction; 3. Development: Select a developer according to the type of photoresist, immerse the exposed sample in the developer, and then rinse it with deionized water to terminate the development; 4. Pattern transfer (etching): Select methods such as reactive ion etching according to the type of the two-dimensional material layer; after setting parameters such as etching gas and power, place the sample in the equipment for etching to transfer the pattern; 5. Removal of photoresist: Dissolve the residual photoresist with a stripping solution such as acetone, assisted by heating or ultrasonic, and finally rinse it with deionized water and dry it with nitrogen.

[0028] In some embodiments, nano-patterning is performed on the two-dimensional material layer to form a two-dimensional material layer with a nano-array arrangement, where the length of a single two-dimensional material layer with a nano-array arrangement is 10 - 500 nm and the width is 10 - 500 nm; the distance between adjacent two-dimensional material layers with a nano-array arrangement is 50 - 500 nm.

[0029] In some embodiments, the nitride nanoparticles are prepared by metal-organic chemical vapor deposition; the two-step preparation process is as follows: first, a metal-organic source is pre-passed to form metal droplets; after turning off the metal-organic source, ammonia is introduced and reacts with the metal droplets under appropriate conditions to grow nitride nanoparticles; the temperature is raised for annealing to improve the crystal quality of the nitride nanoparticles; the edges of the two-dimensional material layer arranged in a nanoarray are rich in unsaturated dangling bonds, providing low-energy sites for the nucleation of nitride nanoparticles and controlling the regular arrangement of nitride nanoparticles along the boundaries of its nano-patterns; therefore, characteristics such as the arrangement interval, unit size, and period of the nitride nanoparticles can be optimized and regulated through the nano-patterns of the two-dimensional material layer.

[0030] In some embodiments, the nitride nanoparticles are GaN nanoparticles; Growing nitride nanoparticles on the edges of the two-dimensional material layer arranged in a nanoarray specifically includes: Placing the substrate with the two-dimensional material layer arranged in a nanoarray in the reaction chamber, first introducing the TMGa source into the reaction chamber to form Ga metal droplets and adsorb them to the edges of the two-dimensional material layer arranged in a nanoarray; after closing the TMGa source, then introducing NH 3 Perform a chemical reaction to form a GaN nanoparticle array on the edges of the two-dimensional material layer arranged in a nanoarray.

[0031] In some embodiments, the n-type doped nitride epitaxial layer is an n-Al x Ga 1-x N layer, 0.15 ≥ x ≥ 0.35; the thickness of the n-Al x Ga 1-x N layer is 450 - 550 nm.

[0032] In some embodiments, the two-dimensional material layer includes any one of a graphene layer, a boron nitride layer, and a transition metal dichalcogenide layer.

[0033] In some embodiments, to grow a two-dimensional material layer on the n-type doped nitride epitaxial layer, the following two methods can be used. The first method: grow the two-dimensional material on a catalytic metal Cu foil by chemical vapor deposition and then transfer it to the n-type doped nitride epitaxial layer by wet transfer; the second method: use an ultra-high temperature chemical vapor deposition system (>1200 degrees Celsius) to directly epitaxially grow a two-dimensional material layer on the n-type doped nitride epitaxial layer.

[0034] In some embodiments, the preparation method of the n-Al x Ga 1-x N layer includes: Prepare the n-Al x Ga 1-x N layer by metal-organic chemical vapor deposition, using TMAl (trimethylaluminum), TMGa (trimethylgallium), and NH3 As an Al source, a Ga source, and an N source respectively, with SiH 4 As a doping source, the growth temperature is 1100 - 1200 °C.

[0035] In some embodiments, the method for preparing the graphene layer includes: The graphene layer is prepared by ultra-high temperature chemical vapor deposition method, using CH 4 , H 2 and N 2 As a C source, a reducing gas, and a carrier gas respectively, the growth temperature is 1150 - 1200 °C, and the flow rate ratio of CH 4 , H 2 and N 2 is (1 - 2):(10 - 20):(100 - 120). Due to the relatively low migration barrier of metal atoms on the graphene surface, the nitride nanoparticles can only nucleate and grow at the edges of the two-dimensional material layer arranged in a nanoarray; meanwhile, the source introduction time and reaction time are precisely controlled to optimize the diameter of a single nitride nanoparticle, leaving the central region of the graphene nanograph exposed.

[0036] In some embodiments, the graphene layer is a single-layer graphene or a bilayer graphene. The thickness of the single-layer graphene is about 0.335 nm, and the bilayer graphene is stacked by two layers of single-layer graphene with a thickness of about 0.67 nm.

[0037] In some embodiments, the substrate includes any one of a sapphire substrate, a silicon carbide substrate, and a silicon substrate.

[0038] Based on the same inventive concept, the present invention also provides an application of the nitride nanoparticle array prepared by the above preparation method in the preparation of a photodetector.

[0039] Based on the same inventive concept, the present invention also provides a photodetector, and its preparation method includes the following steps: Prepare nitride nanoparticles to grow at the edges of the two-dimensional material layer arranged in a nanoarray according to the above method; Prepare a first electrode on the surface of the two-dimensional material layer arranged in a nanoarray; Prepare a second electrode on the n-type doped nitride epitaxial layer and between any two adjacent two-dimensional material layers arranged in a nanoarray.

[0040] Specifically, refer to Figure 2As shown, nitride nanoparticles 4 are grown on the edge of the two-dimensional material layer arranged in a nanoarray according to the above method; a first electrode 5 is prepared on the surface of the two-dimensional material layer arranged in a nanoarray; a second electrode 6 is prepared between any two adjacent two-dimensional material layers arranged in a nanoarray; the two-dimensional material layer and the nitride nanoparticle array arranged in a nanoarray are regularly arranged, and the unit device is a pixel in array imaging; the basic structure of a single device is an n-type doped nitride epitaxial layer - two-dimensional material layer - nitride quantum dots, forming a van der Waals heterojunction structure, and the device has the ability to work self-driven; in a single device, the nitride quantum dots serve as an ultraviolet light absorption layer, the two-dimensional material layer such as graphene serves as a carrier transport channel, and the n-type doped nitride epitaxial layer is in contact with the metal grid electrode (i.e., the second electrode) and serves as an extended channel for grating carrier collection; the second electrode is prepared between two adjacent two-dimensional material layers arranged in a nanoarray by electron beam lithography and serves as the n electrode shared by the pixel array; the first electrode is prepared on the surface of a single two-dimensional material layer arranged in a nanoarray surrounded by nitride nanoparticle units. The photodetector of the present invention is used for imaging, and the controllable precision of the nitride nanoparticle array is in the nanometer size. Therefore, in the imaging application of the photodetector, the product has high integration and high imaging resolution.

[0041] In some embodiments, the preparation of the first electrode by electron beam lithography mainly includes steps such as photoresist coating, exposure, development, metal deposition, and stripping.

[0042] In some embodiments, the material of the first electrode 5 includes at least one of Pt, Ti, Ni, and Al.

[0043] In some embodiments, the material of the second electrode 6 includes at least one of Ni, Pt, and Au.

[0044] In some embodiments, the thickness of the first electrode 5 is 30 - 100 nm.

[0045] In some embodiments, the thickness of the second electrode 6 is 30 - 100 nm.

[0046] In some embodiments, the first electrode 5 includes a Ni layer and an Au layer stacked in sequence, and the Ni layer is in contact with the two-dimensional material layer arranged in a nanoarray; the second electrode 6 includes a Ti layer and an Al layer stacked in sequence, and the Ti layer is in contact with the n-type doped nitride epitaxial layer.

[0047] The core of the present invention is to design a two-dimensional nano-patterned substrate for precisely controlling the nucleation sites and growth characteristics of nitride nanoparticles; its theoretical basis is to utilize the dangling bonds provided by the etched boundary defects of two-dimensional materials. Nitride nanoparticles have a lower nucleation energy barrier at these positions, and the two-dimensional material patterns with nano-scale sizes can ensure that metal atoms and nitrogen atoms reach the etched boundary of two-dimensional materials within the effective migration length, thereby realizing the controllable preparation of nitride nanoparticles; each group of regularly arranged nitride nanoparticles can serve as a single pixel of a photodetector. Therefore, its high-density array can achieve high-integration photodetector imaging applications. In the photodetector structure, a two-dimensional material-nitride van der Waals heterojunction with a vertical structure is designed, and metal electrodes are located on these two materials respectively; the built-in electric field of the van der Waals heterojunction can realize the automatic separation and collection of photo-generated charges, and it can work under zero bias voltage, with self-driven light response ability. This method for growing nitride nanoparticle arrays provides an effective approach for the preparation of high-integration, high-sensitivity, and self-driven photodetectors. The photodetector array prepared based on this method will play an important role in harsh / unmanned environments such as fire warning and deep space exploration.

[0048] The following further illustrates the method for growing nitride nanoparticle arrays, their applications, and photodetectors of the present application with specific examples. This part further illustrates the content of the present invention in combination with specific examples, but should not be construed as a limitation to the present invention. Unless otherwise specified, the technical means adopted in the examples are conventional means well-known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in the art.

[0049] Example 1 The present invention provides a method for growing nitride nanoparticle arrays, including the following steps: S1. Clean the sapphire substrate in acetone, ethanol, and deionized water for 5 minutes each in sequence. After drying with a nitrogen gun, place it in an oven for drying and reserve. S2. Grow an n-Al x Ga 1-x N layer on the substrate surface, where x = 0.22, and the thickness of the n-Al x Ga 1-x N layer is 450 nm; the preparation method of the n-Al x Ga 1-x N layer includes: preparing the n-Al x Ga 1-x N layer by metal-organic chemical vapor deposition, using TMAl, TMGa, and NH 3 as the Al source, Ga source, and N source respectively, and using SiH 4As a doping source, the growth temperature is 1125 °C, and the flow rate ratio of TMGa to TMAl is 1:6. Specifically, the flow rate of TMAl is 500 sccm, the flow rate of TMGa is 3000 sccm, the flow rate of NH 3 is 5000 sccm, and the flow rate of SiH 4 is 300 sccm; S3. Grow a graphene layer on the n-Al x Ga 1-x N layer. The preparation method of the graphene layer (specifically bilayer graphene) includes: Prepare the graphene layer by ultra-high temperature chemical vapor deposition. Use CH 4 , H 2 and N 2 as the C source, reducing gas and carrier gas respectively. The growth temperature is 1170 °C, and the flow rate ratio of CH 4 , H 2 and N 2 is 1:10:100; S4. Perform nano-patterning on the graphene layer to form a graphene layer with a nano-array arrangement. The length of a single graphene layer with a nano-array arrangement is 100 nm, the width is 100 nm, and the distance between adjacent graphene layers with a nano-array arrangement is 80 nm; Specifically, based on two-beam interference holographic exposure, form a nano-scale pattern array on the photoresist film, and then use plasma etching to transfer the pattern to the graphene layer to form a graphene layer with a nano-array arrangement; the wavelength of the light source is 355 nm. After the laser light source is split and then focused, a nano-scale interference light fringe pattern is formed; the size of the interference spot can be adjusted by beam expansion, and the period parameter of the fringe pattern can be regulated by the convergence angle of the focused beam and the wavelength of the light source; for the graphene nano-patterning method, first spin-coat an AZ5214 photoresist film on the complete graphene layer with a thickness of 500 nm; based on the positive photoresist process, control the exposure dose to 50%, the exposure time to 30 seconds, and the development time to 25 seconds; for the Figure 1 square array nano-pattern shown, perform two exposures on the photoresist film with perpendicular directions; after forming the square array nano-pattern on the complete graphene, use plasma etching to transfer the pattern structure to the graphene; the conditions for plasma cleaning etching are: the power is 50%, the gas type is air, and the etching time is 10 minutes; the photoresist pattern mask is dissolved and removed in acetone, and finally a graphene layer with a nano-array arrangement is prepared; S5. Grow GaN nanoparticles on the edges of the graphene layers arranged in a nanoarray; specifically, it includes: placing the substrate with the graphene layers arranged in a nanoarray in the reaction chamber, first introducing the TMGa source into the reaction chamber to form Ga metal droplets and adsorb them on the edges of the graphene layers arranged in a nanoarray for 10 seconds; after closing the TMGa source, then introducing NH for 10 seconds 3 to carry out a chemical reaction to form a GaN nanoparticle array on the edges of the graphene layers arranged in a nanoarray.

[0050] Example 2 This example also provides a photodetector, and its preparation method includes the following steps: S1. Prepare to grow GaN nanoparticles on the edges of the graphene layers arranged in a nanoarray according to the method in Example 1; S2. Prepare the first electrode on the surface of the graphene layers arranged in a nanoarray; S3. Prepare the second electrode on the n-Al x Ga 1-x N layer and between any two adjacent graphene layers arranged in a nanoarray; The first electrode includes a Ni layer (thickness 30 nm) and an Au layer (thickness 30 nm) stacked in sequence, and the Ni layer is in contact with the two-dimensional material layer arranged in a nanoarray; the second electrode includes a Ti layer (thickness 30 nm) and an Al layer (thickness 50 nm) stacked in sequence, and the Ti layer is in contact with the n-type doped nitride epitaxial layer.

[0051] Performance test Figure 3 are the I-V characteristic curves of the two-dimensional material-nitride van der Waals heterojunction type photodetector in Example 2 in the light state and the dark state. Figure 3 In it, I light is the light state, and I dark is the dark state.

[0052] From Figure 3 it can be seen that there is a difference in the current values of the photodetector in Example 2 at zero bias in the light state and the dark state, and the current in the light state is significantly greater than that in the dark state, indicating that the photodetector can generate current only by relying on light illumination and the internal built-in electric field without an external voltage, thus proving its self-driven ability.

[0053] The above is only the preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for growing a nitride nanoparticle array, characterized in that: The following steps are involved: growing an n-type doped nitride epitaxial layer on the surface of the substrate; growing a two-dimensional material layer on the n-type doped nitride epitaxial layer; Performing nano-patterning on the two-dimensional material layer to form a two-dimensional material layer arranged in a nano-array; Nitride nanoparticles are grown on the edge of the two-dimensional material layer arranged in a nano-array.

2. The method for growing a nitride nanoparticle array according to claim 1, wherein: The step of performing nano-patterning on the two-dimensional material layer to form a two-dimensional material layer arranged in a nano-array includes: Nanoimprinting is used to form a nano-sized film pattern mask, and combined with reactive ion etching, the pattern is transferred to the two-dimensional material layer to form a two-dimensional material layer with a nano-array arrangement; Alternatively, performing nano-patterning on the two-dimensional material layer to form a two-dimensional material layer with a nano-array arrangement comprises: Based on double-beam interference holographic exposure, a nano-sized pattern array is formed on the film, and then plasma etching is used to transfer the pattern to the two-dimensional material layer to form a two-dimensional material layer with a nano-array arrangement.

3. The method for growing a nitride nanoparticle array according to claim 1, wherein: The nitride nanoparticles are GaN nanoparticles; Growing nitride nanoparticles at the edge of the two-dimensional material layer arranged in a nano-array, specifically comprising: A substrate with a two-dimensional material layer arranged with nanoarrays is placed in a reaction chamber. A TMGa source is first introduced into the reaction chamber to form Ga metal droplets, which are adsorbed to the edge of the two-dimensional material layer arranged with nanoarrays. After the TMGa source is turned off, NH3 is introduced for a chemical reaction to form a GaN nanoparticle array at the edge of the two-dimensional material layer arranged with nanoarrays.

4. The method for growing a nitride nanoparticle array according to claim 1, wherein: The n-type doped nitride epitaxial layer is n-Al x Ga 1-x N layers, 0.15 ≥ x ≥ 0.35; The n-Al x Ga 1-x The thickness of the N layer is 450~550nm.

5. The method for growing a nitride nanoparticle array according to claim 1, wherein: The two-dimensional material layer includes any one of a graphene layer, a boron nitride layer and a transition metal dichalcogenide layer.

6. The method for growing a nitride nanoparticle array according to claim 4, wherein: The n-Al x Ga 1-x The preparation method of the N layer comprises: n-Al was prepared by metal-organic chemical vapor deposition x Ga 1-x The N layer uses TMAl, TMGa and NH3 as Al source, Ga source and N source respectively, SiH4 as doping source, and the growth temperature is 1100~1200℃.

7. The method for growing a nitride nanoparticle array according to claim 5, wherein: The method for preparing the graphene layer comprises: The graphene layer was prepared by ultra-high temperature chemical vapor deposition, with CH4, H2 and N2 as C source, reducing gas and carrier gas respectively. The growth temperature was 1150~1200℃, and the flow ratio of CH4, H2 and N2 was (1~2):(10~20):(100~120).

8. Use of a nitride nanoparticle array prepared by the growth method according to any one of claims 1 to 7 in preparing a photodetector.

9. A photoelectric detector, characterized in that: The preparation method comprises the following steps: Prepare nitride nanoparticles grown on the edge of a two-dimensional material layer arranged in a nanoarray according to any one of claims 1 to 7; Prepare a first electrode on the surface of the two-dimensional material layer arranged in the nanoarray; A second electrode is prepared on the n-type doped nitride epitaxial layer and between any two adjacent two-dimensional material layers arranged in nanoarrays.

10. The photodetector according to claim 9, wherein: The material of the first electrode includes at least one of Pt, Ti, Ni, and Al; The material of the second electrode includes at least one of Ni, Pt, and Au; The thickness of the first electrode is 30-100 nm; The thickness of the second electrode is 30-100 nm.

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