WO2021104527A1 - 光电化学光探测器及其制备方法 - Google Patents

光电化学光探测器及其制备方法 Download PDF

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WO2021104527A1
WO2021104527A1 PCT/CN2020/136486 CN2020136486W WO2021104527A1 WO 2021104527 A1 WO2021104527 A1 WO 2021104527A1 CN 2020136486 W CN2020136486 W CN 2020136486W WO 2021104527 A1 WO2021104527 A1 WO 2021104527A1
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gallium nitride
nanowires
substrate
algan
photoelectrochemical
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PCT/CN2020/136486
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English (en)
French (fr)
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孙海定
汪丹浩
方师
张伟
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中国科学技术大学
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y15/00—Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y20/00—Nanooptics, e.g. quantum optics or photonic crystals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y40/00—Manufacture or treatment of nanostructures
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/48—Photometry, e.g. photographic exposure meter using chemical effects

Definitions

  • the present disclosure relates to the technical field of photoelectrochemical photodetectors, in particular to a novel photoelectrochemical photodetector and a preparation method thereof.
  • Photodetectors that is, devices that capture light signals and convert them into electrical signals, are widely used in imaging, communication, sensing, computing, emerging wearable devices, and detection in the space field. Photoelectric detectors are widely used in various fields of military and national economy. In the visible or near-infrared band, it is mainly used for ray measurement and detection, industrial automatic control, photometric measurement, etc.; in the infrared band, it is mainly used for missile guidance, infrared thermal imaging, infrared remote sensing, etc.; the ultraviolet band is mainly used for flame detection and missile warning , Ozone monitoring and non-line-of-sight optical communication, etc.
  • MSM Metal-Semiconductor-Metal
  • Today's photodetectors are mostly based on simple Metal-Semiconductor-Metal (MSM) structure.
  • MSM structured photodetectors need to apply an external bias when working, which not only consumes electricity, but also in terms of responsivity and response speed. Aspects also need to be improved; at the same time, in order to meet the needs of different applications, the material system and structure involved in the research of the MSM structure photodetector are complicated, and there is no unified design and preparation method, which can not be adapted to mass production and can be applied to various wavelengths of light. The need for detectors.
  • One aspect of the present disclosure provides a method for preparing a photoelectrochemical photodetector.
  • the method includes: selecting a gallium nitride-based material component according to the wavelength of the light to be detected by the photodetector; Forming gallium nitride-based nanowires on the GaN-based nanowires; modifying promoter nanoparticles on the gallium nitride-based nanowires; encapsulating the gallium nitride-based nanowires modified with the promoter nanoparticles to obtain a photoelectrode; and preparing the photoelectrode Photoelectrochemical photodetector.
  • the detection light wavelength corresponds to the In component in In x Ga lx N.
  • Eg is the forbidden band width of the compound semiconductor, corresponding to the absorption wavelength of different optical wavelength bands.
  • the corresponding absorption wavelength can be obtained by the band gap.
  • forming gallium nitride-based nanowires on the surface of the substrate according to the composition further includes: forming a nanohole array structure on the substrate, and the thickness of the nanohole array structure is less than or equal to 50 nm; The hole is positioned and filled with p-type doped or n-type doped gallium nitride-based material to form a composite layer, and p-type doped or n-type doped nitrogen is continuously formed on the surface of the composite layer at the position corresponding to the nanohole Gallium-based nanowires; or remove the nanohole array structure of the composite layer to form p-type doped or n-type doped gallium nitride-based nanowires on the surface of the substrate.
  • forming a gallium nitride-based nanowire on a surface of a substrate according to the composition further includes: forming a p-type doped or n-type doped gallium nitride-based film on the substrate , Etching the gallium nitride-based film to form the p-type doped or n-type doped gallium nitride-based nanowires on the surface of the substrate.
  • forming gallium nitride-based nanowires on the surface of the substrate according to the above composition includes: controlling the doping ratio of magnesium or silicon, and forming p-type doping or doping with corresponding doping ratio on the substrate. n-type doped gallium nitride based nanowires.
  • the method before the gallium nitride-based nanowires are modified with the promoter nanoparticles, the method further includes: when the gallium nitride-based nanowires are n-type doped, preparing on the surface of the gallium nitride-based nanowires The protective layer, the thickness of the protective layer is less than or equal to 10 nm.
  • modifying the co-catalyst nanoparticles on the gallium nitride-based nanowires includes: disposing the gallium nitride-based nanowires in a precursor aqueous solution of a first concentration, and simultaneously applying energy bands with the nanowires. The light of the corresponding wavelength is irradiated to modify the promoter nanoparticles on the surface of the gallium nitride-based nanowires.
  • encapsulating the gallium nitride-based nanowires of the modified promoter nanoparticles to obtain the photoelectrode includes: fixing and attaching the wires to the gallium nitride-based nanowires equipped with the modified promoter nanoparticles On the conductive area of the substrate, the wire and the substrate are covered and fixed while exposing the gallium nitride-based nanowire to form a packaged photoelectrode.
  • fixing and attaching a wire to a conductive area of a substrate of gallium nitride-based nanowires with modified co-catalyst nanoparticles includes: scraping off the oxide layer on the conductive area of the substrate. Except for the conductive area of the oxide layer, the conductive area is coated with liquid alloy, and the conductive glue is coated on the surface of the wire between the wire and the conductive area and opposite to the position of the liquid alloy.
  • preparing a photoelectrochemical photodetector by using a photoelectrode includes: arranging a photoelectrode, a reference electrode, and a counter electrode at a certain interval in a second concentration of electrolyte solution to prepare a three-electrode system to form a photoelectrochemistry Light detector.
  • gallium nitride-based nanowires on the surface of the substrate according to the composition also includes: forming a nanohole array structure of silicon dioxide, silicon nitride, titanium dioxide, pure metal, etc. on the substrate, Hole array structure and its thickness does not exceed 50nm or less; Position and fill gallium nitride-based material in the nanoholes to form a composite layer, and continue to form gallium nitride-based nanowires on the surface of the composite layer corresponding to the positions of the nanoholes Or remove the silicon dioxide nanohole array structure of the composite layer to form gallium nitride-based nanowires on the surface of the substrate.
  • forming a gallium nitride-based nanowire on the surface of the substrate according to the composition further includes: forming a gallium nitride-based film on the substrate by molecular beam epitaxy, and comparing the gallium nitride-based film to the gallium nitride-based film. Dry etching is performed to form gallium nitride-based nanowires on the surface of the substrate.
  • FIG. 1A is a schematic diagram of AlGaN nanowires in an embodiment of the present disclosure
  • 1B is a scanning electron microscope image of AlGaN nanowires in an embodiment of the present disclosure
  • FIG. 2 is a schematic diagram of modified co-catalyst nano-Pt particles in AlGaN nanowires in an embodiment of the present disclosure
  • 3A is a schematic diagram of a package cross-sectional view of an AlGaN nanowire photocathode in an embodiment of the present disclosure
  • FIG. 3B is a schematic diagram of packaging the AlGaN nanowire photocathode in an embodiment of the present disclosure
  • FIG. 4 is a schematic diagram of the preparation of a novel solar-blind ultraviolet photoelectrochemical photodetector in an embodiment of the present disclosure
  • FIG. 5 is a schematic diagram of a product of a novel solar-blind ultraviolet photoelectrochemical photodetector in an embodiment of the present disclosure
  • Fig. 6 is a schematic flow chart of a preparation method of a photoelectrochemical photodetector in an embodiment of the present disclosure
  • FIG. 7 is a simple comparison diagram of the spectra of the photoelectrochemical photodetector in an embodiment of the present disclosure
  • FIG. 8A is a schematic diagram of an AlGaN nanohole array of solar-blind ultraviolet photoelectrochemical photodetectors in an embodiment of the present disclosure
  • FIG. 8B is a schematic diagram of an AlGaN nanohole array with modified promoter nanoparticles in a solar-blind ultraviolet photoelectrochemical photodetector in an embodiment of the present disclosure
  • FIG. 9 is a schematic diagram of a method for preparing a solar-blind ultraviolet photoelectrochemical photodetector in an embodiment of the present disclosure.
  • 10A is a schematic diagram of the first stage of the preparation process of the AlGaN nanohole array in the solar-blind ultraviolet photoelectrochemical photodetector preparation method in an embodiment of the present disclosure
  • 10B is a schematic diagram of the first stage of the preparation process of the AlGaN nanohole array in the solar-blind ultraviolet photoelectrochemical photodetector preparation method in an embodiment of the present disclosure
  • 10C is a schematic diagram of the first stage of the preparation process of the AlGaN nanohole array in the solar-blind ultraviolet photoelectrochemical photodetector preparation method in an embodiment of the present disclosure
  • 10D is a schematic diagram of the first stage of the preparation process of the AlGaN nanohole array in the solar-blind ultraviolet photoelectrochemical photodetector preparation method in an embodiment of the present disclosure
  • 10E is a schematic diagram of the first stage of the preparation process of the AlGaN nanohole array in the solar-blind ultraviolet photoelectrochemical photodetector preparation method in an embodiment of the present disclosure
  • 10F is a schematic diagram of the first stage of the preparation process of the AlGaN nanohole array in the solar-blind ultraviolet photoelectrochemical photodetector preparation method in an embodiment of the present disclosure
  • 10G is a schematic diagram of the first stage of the preparation process of the AlGaN nanohole array in the solar-blind ultraviolet photoelectrochemical photodetector preparation method in an embodiment of the present disclosure
  • 10H is a schematic diagram of the first stage of the preparation process of the AlGaN nanohole array in the solar-blind ultraviolet photoelectrochemical photodetector preparation method in an embodiment of the present disclosure.
  • the photoelectrochemical photodetector is derived from the photoelectrochemical reaction.
  • the photoelectrochemical reaction means that the semiconductor generates photoelectrons and holes when exposed to light.
  • the electrons undergo a reduction reaction at the semiconductor electrode, and the holes flow through the external circuit to the counter electrode to undergo oxidation reaction (the opposite is true for n-type semiconductors).
  • the performance indicators tested in this process, the ratio of light/dark current, and the response time are directly related to the intensity of light and the wavelength of light, and a photoelectrochemical device dedicated to light detection is gradually derived from this.
  • photoelectrochemical catalysis focuses on the study of chemical reaction mechanisms, such as studying the amount of hydrogen produced by semiconductor materials during the photoelectric catalytic reaction, how to increase the amount of hydrogen produced, and how to design reaction sites.
  • the photoelectrochemical photodetector mainly studies the photo-dark current signal generated in the above photoelectrochemical reaction process to reflect the relevant parameters of the detection light, and then realize various photoelectric detection functions.
  • group III and V nitride semiconductor materials are mainly focused on light-emitting diodes (Light Emitting Diode, or LED) and power devices, and the cost of preparing nitrides is extremely high due to, for example, molecular beam epitaxy (MBE).
  • MBE molecular beam epitaxy
  • nitride nanomaterials for photoelectrochemical catalysis research is still in its infancy, not to mention the use of group III-V nitride materials as photoelectrochemical photodetectors.
  • ultraviolet light detection non-blind band selects chemically prepared powder samples (such as zinc oxide ZnO, titanium dioxide TiO 2 etc.).
  • the present disclosure creatively proposes a GaN-based nanowire/nanopore structure, which is applied to a photoelectrochemical photodetector, which overcomes technical problems in the field and achieves breakthrough technical effects.
  • FIG. 1A is a schematic diagram of an AlGaN nanowire in an embodiment of the present disclosure.
  • the new solar-blind ultraviolet photoelectrochemical photodetector includes a photocathode.
  • the photocathode includes a substrate 110 and also includes AlGaN nanowires 120 grown on the surface of the substrate 110, thereby forming the new photoelectrochemical photodetector photocathode proposed in the present disclosure.
  • the basic structure of 100 include n-type GaN-based nanowires and p-type GaN-based nanowires.
  • the nanowire structure can be a regular arrangement, such as a nanowire structure prepared by directional growth, or it can also include an irregularly arranged nanowire structure.
  • regular can be understood as whether the nanowire arrangement has Periodicity; correspondingly, the so-called “irregularity” can be understood as whether the arrangement of nanowires is not periodic, it can also be understood as the length and diameter of the nanowires, the distance between any adjacent nanowires, and the growth angle of the nanowires Inconsistent (relative to the substrate), no rules to follow.
  • the gallium nitride-based material can be selected as AlGaN in the present disclosure.
  • AlGaN is only a symbolic expression for this material, and does not represent the standard chemical formula of the material.
  • the chemical formula of the GaN-based material can be Al x Ga lx N, one of B x Al y Galxy N or In x Al y Galxy N, 0 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 1. That is, the gallium nitride-based material may be AlGaN or InGaN, or a gallium nitride-based material such as AlInGaN, which is not limited in the present disclosure.
  • the photoelectrode mentioned in the claims in the present disclosure can be a photocathode or a photoanode, and can be specifically distinguished by its doping component (such as magnesium doping or silicon doping), which corresponds to the reduction in the present disclosure. Reaction or oxidation reaction.
  • the present disclosure mainly uses the AlGaN photocathode as an example for description. Those skilled in the art should understand that it is not a limitation on the photoanode, nor is it a limitation on the non-AlGaN photoelectrode.
  • the AlGaN nanowires 120 grown on the surface of the substrate 110 can be obtained by molecular beam epitaxy (MBE) or metal organic chemical vapor deposition (MOCVD) ,
  • MBE molecular beam epitaxy
  • MOCVD metal organic chemical vapor deposition
  • the conventional chemical vapor deposition method, halide vapor phase epitaxy or pulsed laser deposition and other methods are used for preparation, which are not specifically limited in the present disclosure.
  • MBE molecular beam epitaxy
  • MOCVD metal organic chemical vapor deposition
  • the AlGaN nanowire 120 of the present disclosure has the advantages of high stability, high crystal quality, and adjustable band gap height compared with ordinary oxide and nitride nanomaterials (such as gallium oxide nanostructures). It has excellent water reduction performance under blind light irradiation, which is reflected in excellent light detection performance.
  • the band gap can be changed with the doping of the composition, specifically:
  • Eg is the semiconductor forbidden band width, corresponding to the absorption wavelength of different optical wavelength bands.
  • the band gap of the prepared photocathode can be precisely adjusted to achieve light absorption in the solar-blind ultraviolet band.
  • the corresponding wavelength calculation formula can be performed accordingly
  • the transformation is specifically based on actual preparation requirements, which is not limited in this disclosure.
  • the AlGaN nanowires with high crystal quality prepared in the present disclosure may be p-type doped materials, specifically, Mg atoms may be doped.
  • Mg atoms may be doped.
  • the Fermi energy level of the water-semiconductor system is the same, and the p-type semiconductor energy band is bent downward, causing electrons to move to the contact surface, and the surface is rich in electrons.
  • the process will not cause any impact on AlGaN nanomaterials or structures.
  • oxide nanomaterials that have not yet achieved p-type doping such as gallium oxide nanostructures
  • the stability is very high, and it can be used as a photocathode.
  • the substrate 110 includes a conductive substrate, and the conductive substrate includes a standard low-resistance silicon substrate, such as a silicon wafer with overall conductivity.
  • the size of the silicon substrate may be 1cm ⁇ 1cm, and the specific size depends on The size of the photoelectrode is required, which is not limited in this disclosure.
  • the silicon substrate includes an n-type silicon substrate, and the n-type silicon substrate is an n-type silicon substrate with any crystal plane, for example, a Si(111) surface substrate; it also includes a p-type silicon substrate, p
  • the type silicon substrate is a p-type silicon substrate with any crystal plane, for example, a Si (100) plane substrate.
  • GaN-based nanowires with high crystal quality can be stably formed on the substrate.
  • the silicon substrate is only an optional substrate in the present disclosure.
  • the substrate includes any conductive solid substrate (which can be understood as a substrate with a conductive layer grown on the surface), including metal, conductive silicon, and silicon.
  • FIG. 1B is a scanning electron microscope image of AlGaN nanowires in an embodiment of the present disclosure.
  • the average length of a single nanowire of the AlGaN nanowire 120 is 10 nm-5000 nm, optionally in the range of 300 nm-400 nm; the average diameter of a single nanowire is 5 nm-5000 nm, optionally 60 nm-80 nm. This makes the specific surface area of the nanowire larger, and at the same time increases the rate of the redox reaction in the photodetection process.
  • the coverage (or filling rate) of the AlGaN nanowire 120 is 1%-99%, and may be about 70%.
  • the coverage density is equivalent to the percentage of the total area of the upper surface of the nanowires to the surface area of the entire substrate, which is used to reflect the distance between the nanowires, the number of nanowires per unit surface, and so on.
  • the photoelectrode includes a photoanode formed by n-type GaN-based nanowires and a photocathode formed by p-type GaN-based nanowires, and also includes promoter nanoparticles distributed on the surface thereof.
  • the GaN-based nanowires are n-type GaN-based nanowires
  • the surface of the photoelectrode further includes a protective layer formed on the surface of the n-type GaN-based nanowires, and the thickness of the protective layer is less than or equal to 10 nm. It is used to prevent the occurrence of photo-corrosion of GaN-based nanowires, and the protective layer is titanium dioxide (TiO 2 ) or other protective materials.
  • FIG. 2 is a schematic diagram of modified co-catalyst nano-Pt particles in AlGaN nanowires in an embodiment of the present disclosure.
  • the photocathode further includes cocatalyst nanoparticles 210 modified on the surface of the nanowire in the AlGaN nanowire 120, and the cocatalyst nanoparticle The size of 210 is 0.1nm-1000nm.
  • the corresponding n-type gallium nitride-based nanowires in the present disclosure can be used as the optoelectronics in the present disclosure.
  • the n-type nanowire can optionally form at least one protective layer on the surface of the nanowire before modifying the co-catalyst nanoparticles.
  • the protective layer can be a protective layer made of the aforementioned titanium dioxide and other materials. To prevent the photo-corrosion phenomenon of n-type GaN-based nanowires, it will not be repeated here.
  • nanowire surface On the nanowires of AlGaN nanowires 120, photodeposition, or atomic layer deposition (Atomic Layer Deposition, ALD), electrodeposition (chemical loading method), and immersion method (chemical loading method) are used to modify the co-catalyst nanoparticles on the nanowires. Nanowire surface.
  • ALD atomic layer deposition
  • electrodeposition chemical loading method
  • immersion method chemical loading method
  • the nanowire of the AlGaN nanowire 120 absorbs photons and produces photogenerated Electron-hole pairs. Then the photogenerated electrons diffuse to the surface of the nanowires. Because the energy of the photogenerated electrons is greater than the reduction potential of the cocatalyst precursor groups in the solution, the photogenerated electrons diffused to the surface of the nanowires will be reduced and modified on the cocatalyst precursor groups on the surface of the AlGaN nanowires.
  • modified nanoparticles 210 on the surface of the AlGaN nanowire 120.
  • the particle size diameter can be 0.1nm-1000nm, 5nm can be selected, and modified on the surface of the nanowire.
  • the co-catalyst significantly enhances the reduction reaction activity of the system, accelerates the reaction rate, and improves the photoresponse performance.
  • the promoter nano-particles 210 include metal particles active in water reduction reaction.
  • the metal particle material includes platinum, rhenium, palladium, iridium, rhodium, iron, cobalt, or nickel, etc., or multiple alloys thereof. The alloy uses two metals at the same time, such as RuFe and RuCo. In the present disclosure, platinum (Pt) is optional.
  • the promoter nanoparticle 210 needs to have proper adsorption energy for water molecules and reduction products, and has a higher water reduction activity, which makes the reduction reaction stronger and the photocurrent signal stronger during the photodetection process.
  • its promoter nano particles can include metal particles with water oxidation reaction activity, including iridium, iron, cobalt, nickel or ruthenium, etc., or their multi-component alloys, which have correspondingly higher Water oxidation is active, and the oxidation reaction is more intense.
  • metal particles with water oxidation reaction activity including iridium, iron, cobalt, nickel or ruthenium, etc., or their multi-component alloys, which have correspondingly higher Water oxidation is active, and the oxidation reaction is more intense.
  • FIG. 3A is a schematic view of the packaging of the AlGaN nanowire photocathode 300 in an embodiment of the present disclosure
  • FIG. 3B is a schematic view of the packaging of the AlGaN nanowire photocathode 300 in an embodiment of the present disclosure.
  • the photoelectrochemical photodetector in order to successfully encapsulate the AlGaN nanowire 120 of the photocathode described above, further includes: a wire 310 arranged in the conductive area of the substrate 110, and the wire 310 and the photocathode are covered and fixed, The cured coating structure 320 of the AlGaN nanowire 120 of the photocathode is exposed. As shown in FIG.
  • a curing window 321 can be formed on the surface of the cured structure of the cured coating structure 320, through which the AlGaN nanowires 120 are exposed, so that in the subsequent light detection process, solar-blind ultraviolet light applied from the outside can directly pass through
  • the curing window 321 is irradiated onto the AlGaN nanowire 120.
  • the optional substrate 110 material here can be a p-type Si (100) surface silicon wafer with an area size of 1 cm ⁇ 1 cm and a thickness between 0.01 mm and 1000 mm.
  • the conductive area nanowires are arranged on the back of the substrate 110.
  • the wires are arranged on the back of the substrate.
  • the conductive area may be a certain area other than the nanowires that is scraped off by a diamond pen on the back or front of the silicon wafer, which is not specifically limited in the present disclosure.
  • the material of the wire 310 includes gold, silver, copper, etc., and the size of the wire 310 is selected to match the size of the substrate 110.
  • a wire 310 with a width of about 1.2 cm and a length of 5 cm may be selected, and the material may be copper Cu.
  • Conductive copper tape can also be used.
  • the material of the cured coating structure 320 includes a liquid material that is curable and has insulating properties after curing, and the cured coating structure 320 is epoxy resin or the like, which has a wrapping and insulating effect.
  • a liquid alloy 330 disposed on the conductive area of the substrate and a conductive glue 340 disposed on the surface of the wire 310 opposite to the liquid alloy 330 are further included.
  • the liquid alloy 330 is a liquid gallium indium (GaIn) alloy, and the purity of the liquid gallium indium (GaIn) alloy is optional between 90% and 99.99999%; and the conductive glue 340 is a silver glue.
  • the liquid alloy 330 can directly contact the conductive surface of the substrate to form an ohmic contact, which can achieve better conductive characteristics and current stability.
  • the conductive glue that also fixes the wire 310 and the substrate 110 and fixes the liquid alloy 330 together between the wire 310 and the substrate 110 not only plays a role of fixing and wrapping, but also has better conductive characteristics and Current stability.
  • a packaged photoelectrode with ohmic contact characteristics is prepared, which can better avoid the Schottky barrier formed by the direct contact between the surface of the conductive area of the substrate and the metal wire, so as to facilitate current conduction.
  • Fig. 4 is a schematic diagram of the preparation of a novel solar-blind ultraviolet photoelectrochemical photodetector in an embodiment of the present disclosure.
  • the photoelectrochemical photodetector 400 further includes: an electrolyte solution (not shown in the figure) in contact with the photocathode structure 300, and a reference electrode 420 and a counter electrode 430 in contact with the electrolyte solution.
  • the electrode 420, the counter electrode 430, and the photocathode 300 are kept at a certain distance, and they are contained together by a light-transmitting container 410 having at least limited solar-blind ultraviolet light absorption capacity; among them, the reference electrode 420, the counter electrode 430 and the photocathode 300 They are respectively connected to an electrochemical workstation 440 with a current monitoring function.
  • the electrochemical workstation 440 has a photocurrent monitoring function. Therefore, a photoelectrochemical photodetector based on a simple water reduction reaction as the photoelectric reaction mechanism is basically constituted. The preparation conditions are simple, the purity requirements are low, and the working process has almost no effect on the electrode materials.
  • the electrolyte solution is an acidic or neutral electrolyte solution
  • the acidic electrolyte solution includes sulfuric acid, hydrochloric acid, and perchloric acid
  • the neutral electrolyte solution is sodium sulfate
  • the concentration of the electrolyte solution is 0.5 mol/L
  • the reference electrode is Silver/silver chloride electrode
  • counter electrode includes platinum electrode and carbon electrode.
  • a complete new solar-blind ultraviolet photoelectrochemical photodetector is formed by the above-mentioned components and the above-mentioned AlGaN nanowire photocathode 300.
  • the new solar-blind ultraviolet photoelectrochemical photodetector can further optimize the photodetection responsivity by modifying the co-catalyst.
  • FIG. 5 is a schematic diagram of a new solar-blind ultraviolet photoelectrochemical photodetector in an embodiment of the present disclosure.
  • the product includes the above-mentioned photoelectrochemical photodetector and a packaging structure 500 for packaging the photoelectrochemical photodetector.
  • the packaging structure 500 includes a housing structure 510 covering the photoelectrochemical photodetector to encapsulate it; the surface of the housing structure 510 is provided with optical
  • the window 511 is provided with a light-transmitting surface 520 matching the optical window 511 for sealing the optical window 511.
  • the distance between the light-transmitting surface 520 and the photocathode surface with the AlGaN nanowire 120 is greater than or equal to 0.01 mm, and the distance can be Choose 0.2cm, but there is no restriction on the specific spacing.
  • the AlGaN nanowires 120 modified with co-catalyst nanoparticles are used to irradiate solar-blind ultraviolet light on the photocathode 300 through the transparent surface 520.
  • the structure is simple, and the preparation materials are easy to obtain.
  • the light-transmitting surface 520 includes a transparent material with limited ability to absorb solar-blind ultraviolet light;
  • the shell structure 510 includes a shell structure formed of a polytetrafluoroethylene material.
  • one surface of the housing structure 510 is provided with a sealable/openable injection hole 530, an exhaust hole 540, and at least three electrode holes 550 for setting a photocathode, a reference electrode, and a counter electrode. , 560, 570.
  • the manufacturing process has low requirements and low cost.
  • the present disclosure proposes a photoelectrochemical photodetector and a preparation method thereof.
  • the present disclosure proposes a gallium nitride-based material nanowire structure to be applied to a photodetector, and accordingly proposes a preparation method of the material structure, which overcomes technical problems in the field and achieves a breakthrough unexpected technology effect.
  • the nanowire structure can be a regular arrangement, such as a nanowire structure prepared by directional growth, or it can also include an irregularly arranged nanowire structure.
  • the so-called “regular” can be understood as an arrangement of nanowires.
  • the so-called “irregularity” can be understood as the arrangement of the nanowires does not have periodicity, and can also be understood as the length and diameter of the nanowires, the distance between adjacent nanowires, and the nanowires on the same substrate.
  • the growth angle of the line (relative to the substrate) is inconsistent, and there is no rule to follow.
  • AlGaN or InGaN is only a symbolic expression of this material, and does not represent the standard chemical formula of this material.
  • the chemical formula of AlGaN may be Al x Ga lx N , One of B x Al y Galxy N or In x Al y Galxy N, 0 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 1. That is, the gallium nitride-based material may be AlGaN or InGaN, or a gallium nitride-based material such as AlInGaN, which is not limited in the present disclosure.
  • the photoelectrode mentioned in the claims in the present disclosure can be a photocathode or a photoanode, and can be specifically distinguished by its doping component (such as magnesium doping or silicon doping), which corresponds to the reduction in the present disclosure. Reaction or oxidation reaction.
  • the present disclosure mainly uses the photoelectrode with the AlGaN or InGaN nanowire structure as an example for description.
  • the AlGaN or InGaN nanowire photocathode mentioned in the specification is not a limitation on the photoanode, nor is it a limitation on the non-AlGaN or InGaN photoelectrode.
  • AlGaN nanowires grown on the surface of the substrate can be grown by molecular beam epitaxy (MBE) or metal organic chemical vapor deposition (MOCVD), which is conventional Chemical vapor deposition, halide vapor phase epitaxy, pulsed laser deposition and other methods are used for preparation, which are not specifically limited in this disclosure.
  • MBE molecular beam epitaxy
  • MOCVD metal organic chemical vapor deposition
  • the following mainly uses molecular beam epitaxy (MBE) as the basic preparation method to introduce.
  • One aspect of the present disclosure provides a method for preparing a photoelectrochemical photodetector. As shown in FIG. 6 in a schematic flow chart of a method for preparing a photoelectrochemical photodetector in an embodiment of the present disclosure, the method includes:
  • the composition of aluminum in the gallium nitride-based material can be controlled, the composition of indium in the gallium nitride-based material can also be controlled, and the composition of aluminum and indium in the gallium nitride-based material can be controlled at the same time. It is very easy to modify and control the proportion of components, and at the same time it is very accurate. Therefore, the preparation of the nanowire material corresponding to the full-spectrum light wavelength can be better adapted, and the preparation process can be simplified.
  • the above is only the introduction of AlGaN or InGaN in the gallium nitride-based material in the embodiments of the present disclosure.
  • the aluminum or indium in the gallium nitride-based material can be replaced with boron, and the corresponding composition adjustment can still be applied to the above solution.
  • the gallium nitride-based nanowire structure prepared by the molecular beam epitaxy method is compared with ordinary oxidation Nanomaterials and nitride nanomaterials (such as gallium oxide nanostructures), with high stability, high crystal quality, and adjustable band gap height, which can ensure excellent water reduction/oxidation performance under light irradiation, that is, light detection performance .
  • S630 Modifying the promoter nanoparticles on the AlGaN nanowires or InGaN nanowires; using a promoter nanoparticle modification method (such as light deposition method) on the AlGaN nanowires or InGaN nanowires, such as atomic layer deposition (Atomic Layer Deposition) Deposition, ALD), electrodeposition (chemical loading method), and dipping method (chemical loading method) modify the co-catalyst nanoparticles on the surface of nanowires.
  • a promoter nanoparticle modification method such as light deposition method
  • ALD atomic layer deposition
  • electrodeposition chemical loading method
  • dipping method chemical loading method
  • S640 Encapsulate AlGaN nanowires or InGaN nanowires modified with co-catalyst nanoparticles to obtain photoelectrodes to prevent leakage in the side or back gaps of the substrate.
  • the epitaxy can also be fixed by curing by silver glue and epoxy resin. sheet.
  • the composition of photoelectrochemical photodetectors includes photoelectrodes. After the photoelectrodes are irradiated with light, photogenerated electron-hole pairs are generated to form currents with other components in the photodetectors. In the loop, the generated photocurrent can be detected by the outside world, which can reflect the photoelectric detection capability for applications in military, industrial, and communications fields.
  • forming AlGaN nanowires or InGaN nanowires on the surface of the substrate according to the composition in S620 includes: setting aluminum (Al) according to the composition of the corresponding gallium nitride-based material
  • the heating program of the source furnace or the indium (In) source furnace is turned on or off, and the gallium nitride-based nanowires of the corresponding composition are formed on the substrate.
  • each elemental source in the source furnace will generate a corresponding atomic beam under ultra-high vacuum and a certain temperature.
  • the on/off and temperature settings of each furnace source can be adjusted to a certain Or the atomic beams generated by multiple furnace sources are precisely controlled to control the generation of gallium nitride-based materials with different compositions.
  • the composition of aluminum in the gallium nitride-based material is controlled to grow AlGaN nanowires, it is only necessary to turn on the aluminum furnace source and the gallium source furnace, and turn off the indium furnace source; if the indium is controlled in the gallium nitride-based material To grow InGaN nanowires, you only need to turn on the indium furnace source and the gallium source furnace, and turn off the aluminum furnace source. Therefore, by controlling the temperature of the source furnace to control the volume flow of the atomic beam of each furnace source, and the timing of opening and closing each furnace source, the technical solution of the present disclosure can further accurately control the composition ratio of the nanowire material.
  • Fig. 7 is a simple comparison diagram of the spectra of the photoelectrochemical photodetector in an embodiment of the present disclosure.
  • the wavelength of light is less than 400nm as the ultraviolet region. Specifically, when the wavelength of light is less than 290nm, the solar-blind ultraviolet region can be reached; visible light
  • the light wavelength is generally between 400nm-700nm; more than 700nm is the infrared light region, and the photoelectrochemical photodetector generally studies the visible light wavelength range.
  • the energy band of the photoelectrode semiconductor material of the photoelectrochemical photodetector is related to the absorption capacity of the material in the corresponding light wavelength range, and the energy band relationship of the photoelectrode semiconductor material is related to the alloy composition ratio of the gallium nitride-based nanomaterial. Therefore, only by controlling the proportion of aluminum or indium when the nanowires are grown, the band gap can be precisely adjusted to achieve full-wavelength absorption of infrared, visible and ultraviolet light.
  • forming AlGaN nanowires or InGaN nanowires on the surface of the substrate according to the composition further includes: forming a nanohole array structure on the substrate, and the thickness of the nanohole array structure is less than or equal to 50 nm; The nanoholes are positioned and filled with p-type doped or n-type doped gallium nitride-based materials to form a composite layer, and the nanohole array structure of the composite layer is removed to form gallium nitride-based nanowires on the surface of the substrate.
  • the reverse formation principle of nanowires/nanopores can be used to prepare silica nanopore structures on the surface of the substrate, for example, a silica nanopore array layer with a thickness of up to 50 nm, and nanopores.
  • the hole can be directly formed through the silicon dioxide layer with the surface of the substrate as the bottom surface.
  • the gallium nitride-based crystal nucleus can be pre-formed in the nanoholes of the silicon dioxide nanohole structure, and then the nanoholes can be filled by molecular beam epitaxy or MOCVD to form AlGaN nanomaterials or InGaN nanomaterials and fill the nanoholes ;
  • molecular beam epitaxy or MOCVD can also be used directly A gallium nitride-based material is formed on the bottom surface of the nanopore.
  • Silicon dioxide can be removed by chemical etching or optical etching, or it can be retained as an isolation layer. If retained, it may affect the modification of the promoter nanoparticles. Therefore, it is optional to remove the silicon dioxide.
  • the length Corresponding to the AlGaN nanomaterials or InGaN nanowires forming the nanopore size, the length can be 200nm.
  • the silicon dioxide layer is removed or not is not the key to this embodiment, and the limiting effect brought about by it restricts the growth of the thin film, so that the present disclosure can control the growth of nanowires in a defined area.
  • the thickness of the silicon dioxide nanohole array layer is only 10-50nm, after filling the nanohole structure on it, the length of the formed AlGaN nanomaterial or InGaN nanowire can still be grown to 200nm.
  • forming AlGaN nanowires or InGaN nanowires on the surface of the substrate according to the composition further includes: forming a nanohole array structure on the substrate, and the thickness of the nanohole array structure is less than or equal to 50 nm; Positioning and filling the gallium nitride-based material in the nanoholes forms a composite layer, and continues to form gallium nitride-based nanowires on the surface of the composite layer at positions corresponding to the nanoholes. At this time, the composite layer is not removed.
  • the thickness of the composite layer is very small, for example, a 20nm composite layer can be selected; on the other hand, the selective area growth method can directly correspond to the nanopore composite layer along the position of the nanopore.
  • the other parts of the nanowires directly form nanowires.
  • the nanowires will actually protrude from the surface of the composite layer and can reach a size of several hundred nanometers or even micrometers. Therefore, the size of the nanowires will be much larger than the size of the composite layer without removing the composite layer. In this case, it will not affect the function of the nanowire.
  • forming AlGaN nanowires or InGaN nanowires on the surface of the substrate according to the composition further comprising: forming an AlGaN film or an InGaN film on the substrate; Etching is performed to form the AlGaN nanowires or InGaN nanowires on the surface of the substrate.
  • an AlGaN film or InGaN film of high crystal quality can be directly formed on the substrate by molecular beam epitaxy or MOCVD method, and then formed on the AlGaN film or InGaN film by micro-nano processing technology.
  • Photoresist, silicon dioxide or small metal islands can then be etched by dry etching methods such as Inductively Coupled Plasma (ICP) or other dry etching methods.
  • ICP Inductively Coupled Plasma
  • the etching speed of silicon or metal is slower, and the remaining unprotected parts are etched faster to form AlGaN nanowires or InGaN nanowires on the substrate.
  • the corresponding substrate can be a silicon wafer or a sapphire substrate.
  • forming AlGaN nanowires or InGaN nanowires on the surface of the substrate according to the above composition includes: controlling the doping ratio of magnesium or silicon, and forming p-type doping with corresponding doping ratio on the substrate Or n-type doped AlGaN nanowires or InGaN nanowires.
  • the nanowire material can be precisely controlled. Doping concentration.
  • forming AlGaN nanowires or InGaN nanowires on the surface of the substrate according to the composition includes: setting the substrate in the preparation cavity, and at the first temperature Degas the preparation chamber for at least the first time, transfer the substrate set in the preparation chamber to the buffer chamber, degas the buffer chamber at the second temperature for at least the second time, and transfer the substrate in the buffer chamber to the growth chamber. Growth of AlGaN nanowires or InGaN nanowires.
  • MBE molecular beam epitaxy
  • a p-type Si (100) substrate ie, silicon wafer
  • the MBE equipment preparation cavity (for example, load lock cavity) is used for degassing preparation, so that the MBE equipment reaches the corresponding vacuum degree, for example, the vacuum degree can reach 10 -9 , and the baking and degassing time is at least satisfied at the first temperature of 200 °C.
  • the first time is 1 hour, after that, the silicon wafers in the preparation chamber are sent to the buffer chamber, and the baking and degassing time is maintained at the second temperature of 600°C for at least 2 hours in the second time to remove the water in the buffer chamber as much as possible And the adsorption of gas molecules to silicon wafers. After the degassing is completed, the silicon wafer is transferred to the growth chamber for the growth of AlGaN nanowires.
  • the aluminum (Al) source furnace or the indium (In) source furnace is controlled to be turned on or off, and the temperature rise program of the source furnace is controlled according to the corresponding AlGaN or InGaN group.
  • the formation of AlGaN nanowires or InGaN nanowires of the corresponding composition on the substrate includes: after the substrate is transferred to the growth chamber, controlling the opening of the gallium (Ga) source furnace connected to the growth chamber to achieve the first equivalent
  • the pressurized gallium beam is used as the gallium source and the plasma nitrogen of the first volume flow rate is used as the nitrogen source, and maintained at the third temperature for at least a third time to form a GaN seed crystal on the surface of the substrate.
  • MBE molecular beam epitaxy
  • a p-type Si (100) substrate ie silicon wafer
  • the connected gallium source furnace uses the first equivalent pressure (BEP) 6.0 ⁇ 10 -8 Torr gallium beam as the gallium source and the first volume flow rate of 1sccm plasma nitrogen to form high-brightness nitrogen plasma as the nitrogen source.
  • BEP first equivalent pressure
  • the aluminum (Al) source furnace or the indium (In) source furnace is controlled to be turned on or off, and the temperature rise program of the source furnace is controlled according to the corresponding AlGaN or InGaN group.
  • forming the AlGaN nanowires or InGaN nanowires of the corresponding composition on the substrate further includes: controlling to turn on the aluminum source furnace or the indium source furnace, and under the condition that the plasma nitrogen of the first volume flow rate is used as the nitrogen source, At four temperatures, the aluminum beam with the second equivalent pressure or the indium beam with the third equivalent pressure is matched with the gallium beam with the fourth equivalent pressure to form AlGaN nanowires or InGaN nanowires of the corresponding composition on the surface of the substrate line.
  • the aluminum source furnace is controlled to open, and under the condition that the first volume flow rate of 1sccm plasma nitrogen is used as the nitrogen source, the second temperature is maintained at 610°C. equivalent pressure 2.0 ⁇ 10 -8 Torr aluminum beam, with the fourth equivalent pressure 3.0 ⁇ 10 -8 Torr gallium beam, an AlGaN nanowire corresponding components in the silicon surface.
  • the indium furnace source is controlled to open, and under the condition that the first volume flow rate of 1sccm plasma nitrogen is used as the nitrogen source, the second temperature is maintained at 610°C. equivalent pressure 2.0 ⁇ 10 -8 Torr aluminum beam, with the fourth equivalent pressure 3.0 ⁇ 10 -8 Torr gallium beam, an AlGaN nanowire corresponding components in the silicon surface.
  • InGaN nanowires are formed, due to the difference between aluminum and indium, it is necessary to turn on the indium furnace source and keep the aluminum furnace source closed, and replace the corresponding aluminum beam current parameters with an indium beam with a third equivalent pressure of 4.0 ⁇ 10 -8 Tor
  • the proportion of the alloy between aluminum and indium in the nanowire can be accurately controlled by the above method, so as to achieve the AlGaN nanowire or InGaN nanowire with the corresponding light wavelength.
  • the composition ratio of aluminum or indium is estimated by comparing the BEP of aluminum or indium and gallium beams, and the BEP ratio is adjusted by controlling the temperature to achieve the purpose of adjusting the composition.
  • the Al equivalent pressure (BEP) between 6 ⁇ 10 -8 Torr and 1 ⁇ 10 -8 Torr to achieve the purpose of adjusting the Al composition; or, the preparation process of InGaN nanowires corresponding to visible light and infrared light
  • BEP Al equivalent pressure
  • the purpose of regulating the In composition is achieved by adjusting the BEP of indium between 4 ⁇ 10 -8 Torr and 1 ⁇ 10 -8 Torr.
  • the aluminum (Al) source furnace or the indium (In) source furnace is controlled to be turned on or off, and the temperature rise program of the source furnace is controlled according to the corresponding AlGaN or InGaN group.
  • forming the AlGaN nanowires or InGaN nanowires of the corresponding composition on the substrate also includes: controlling the opening or closing of the aluminum (Al) source furnace or the indium (In) source furnace, setting the temperature of the magnesium source furnace to the first Control the magnesium source furnace or the silicon source furnace to open or close at five temperatures or when the silicon source furnace is the sixth temperature, so that the AlGaN nanowires or InGaN nanowires of the corresponding composition formed on the substrate become p-type doped or n Type doping.
  • the photoelectrode is divided into photoanode or photocathode.
  • p-type doped AlGaN nanowires or InGaN nanowires can better complete the water reduction reaction, especially when the surface is modified with co-catalyst nanoparticles, it can be used as photoelectrochemistry
  • the photocathode of the system Generally, a certain proportion of magnesium can be doped to make the doped AlGaN nanowires or InGaN nanowires become p-type doped materials. This doping method can achieve better material stability and will not treat doped materials. For any impact, the water reduction reaction will respond better in the later stage.
  • n-type doped AlGaN nanowires or InGaN nanowires can better complete the water oxidation reaction, especially when the surface is modified with co-catalyst nanoparticles, it can be used as a photoanode in a photoelectrochemical system.
  • a certain proportion of silicon can be doped to make the doped AlGaN nanowires or InGaN nanowires become n-type doped materials. This doping method can achieve better water oxidation reaction response.
  • the magnesium source furnace is turned on, and the temperature of the magnesium source furnace is The fifth temperature is 360°C, so that the AlGaN nanowires of the corresponding composition formed on the substrate become p-type doped.
  • the silicon source furnace needs to be turned on, and the sixth reaction temperature of the silicon source furnace is 1180°C.
  • modifying the promoter nanoparticles on the AlGaN nanowires or InGaN nanowires includes: disposing the AlGaN nanowires or InGaN nanowires in a precursor aqueous solution of a first concentration, and simultaneously applying the nanowires and the nanowires. It can be irradiated with light of corresponding wavelength to modify the promoter nanoparticles on the surface of AlGaN nanowires or InGaN nanowires.
  • a certain concentration of chloroplatinic acid solution can be selected as the precursor aqueous solution, and the grown p-type Al x Ga lx
  • the N nanowires are placed in 50mL deionized water, in a sealed container, the reaction temperature is maintained at 10°C by circulating water cooling, and a certain vacuum is maintained.
  • inert gas such as argon is introduced into the container as a protective gas, and the concentration of 1ml is 10mg / ml solution of chloroplatinic acid into the container, and light is applied to Al x Ga lx N nanowire bandgap corresponding to a wavelength of light holding time exceeds 30 minutes. Due to the semiconductor photoelectric effect, Al x Ga lx N nanowires generate photo-generated electron-hole pairs after absorbing photons. Then the photogenerated electrons diffuse to the surface of the nanowires.
  • the photogenerated electrons Because the energy of the photogenerated electrons is greater than the reduction potential of the platinum acid radical ([PtCl 6 ] 2- ) group in the solution, the photogenerated electrons diffused to the surface of the nanowire will be reduced and adsorbed on the surface of the nanowire. PtCl 6 ] 2- , forming platinum particles on the surface of the nanowires, that is, the photodeposition process. After the photodeposition reaction is completed, the sample is taken out and cleaned to obtain the p-type AlGaN nanowires modified with the promoter platinum nanoparticles, in which the particle size of the platinum particles can reach 0.1nm-1000nm.
  • n-type nanowires For n-type nanowires, it is only necessary to replace the precursor aqueous solution of chloroplatinic acid solution with a ruthenium chloride solution of equal concentration.
  • the photoelectrode By distributing the modified cocatalyst nanoparticles on the surface of the nanowires, the photoelectrode can react more intensely during the water reduction/oxidation reaction, the reaction speed is faster, and the photocurrent is larger.
  • the method further includes: when the AlGaN nanowires or InGaN nanowires are n-type doped, adding the catalyst nanoparticles to the AlGaN nanowires or InGaN nanowires A protective layer is prepared on the surface of the wire.
  • n-type doping is easier to achieve in the preparation process of molecular beam epitaxy, the grown nanowires are easy to be corroded by self-generated photo-generated holes during the photodeposition or photodetection process, thus causing certain impact on the photoanode Therefore, it is necessary to prepare a nanowire protective layer on the surface of the nanowire on the basis of the nanowire of the photoanode that has a tunnel conduction effect and at the same time has good conductivity and does not affect the light detection performance.
  • an atomic layer deposition method is used to directly deposit a layer of n-type InGaN nanowires on the surface of the n-type InGaN nanowires.
  • the material of the protective layer can be TiO 2 or a material with similar properties to prevent the n-type InGaN nanowire material from photo-corrosion under the condition of hole enrichment.
  • amorphous TiO 2 protective layer tetrakis(dimethylamino)titanium(IV) TEMAT and water can be used as precursors in the preparation process, and the precursor containers are kept at 65°C and 25°C, respectively, for 60 cycles of co-deposition. Each cycle includes the process of introducing titanium precursor for 0.1 seconds, plasma nitrogen for 10 seconds, water vapor for 0.1 seconds, and N 2 for 10 seconds. Finally, amorphous TiO can be formed on the surface of n-type InGaN nanowire materials. 2 protective layer.
  • encapsulating AlGaN nanowires or InGaN nanowires with modified promoter nanoparticles to obtain a photoelectrode includes: fixing and attaching wires to AlGaN nanowires or InGaN nanowires with modified promoter nanoparticles On the conductive area of the wire substrate, the wire and the substrate are covered and fixed while exposing the AlGaN nanowire or the InGaN nanowire to form a packaged photoelectrode. To encapsulate the photoelectrode, attention needs to be paid to lead out the wires, and also attention to expose the nanowires of the photoelectrode.
  • one end of the wire needs to be opposite to the predetermined conductive area of the silicon wafer.
  • the conductive area can be the back or the front of the silicon wafer and use a diamond pen to scrape off a certain area other than the nanowires.
  • the exposed photocathode nanowires facilitate the light of the corresponding light wavelength to directly irradiate the nanowires.
  • fixing and attaching the wire to the conductive area of the substrate of AlGaN nanowires or InGaN nanowires with modified promoter nanoparticles includes: scraping off the oxide layer on the conductive area of the substrate, and The conductive area where the oxide layer is removed is coated with liquid alloy, and the conductive glue is coated on the surface of the wire between the wire and the conductive area and opposite to the position of the liquid alloy.
  • a photoelectrode with ohmic contact characteristics should be prepared.
  • a silicon wafer is used as an example.
  • a diamond knife is used to scrape off the silicon dioxide (SiO 2 ) layer naturally grown on the back of the silicon wafer.
  • the conductive area on the back of the sheet is coated with a liquid alloy (such as a gallium indium (GaIn) alloy) to form an ohmic contact.
  • a liquid alloy such as a gallium indium (GaIn) alloy
  • conductive paste silver (Ag) glue on the copper (Cu) strip of the wire, and compact it with the back of the silicon wafer coated with gallium indium alloy, and finally wrap the entire photoelectrode with epoxy resin, leaving only nanometers
  • the line growth surface is exposed, thereby completing the preliminary packaging of the photoelectrode, avoiding the formation of the Schottky barrier, and facilitating the conduction of the photocurrent.
  • using a photoelectrode to prepare a photoelectrochemical photodetector includes: arranging the photoelectrode, a reference electrode, and a counter electrode in a second concentration of electrolyte solution at a certain interval to prepare a three-electrode system to form a photoelectrochemistry Light detector.
  • the photocathode three-electrode system for preparing p-type AlGaN nanowires as an example, an electrolyte solution solution (with a second concentration of 0.5 mol/L sulfuric acid (H 2 SO 4 ) Aqueous solution as an example), then the Al x Ga lx N nanowire electrode (photocathode) prepared above, the reference electrode (taking silver/silver chloride (Ag/AgCl) as an example), and the counter electrode (taking platinum Pt The mesh electrode is taken as an example) is placed in the electrolyte solution solution, the preparation of the three-electrode system is completed, and the photoelectrochemical photodetector of the present disclosure is basically formed.
  • an electrolyte solution solution solution with a second concentration of 0.5 mol/L sulfuric acid (H 2 SO 4 ) Aqueous solution as an example
  • the Al x Ga lx N nanowire electrode photocathode
  • the reference electrode taking silver/silver chloride (A
  • the electrochemical workstation Connect the electrochemical workstation to the conductive end of each electrode, and set the test parameters of the electrochemical workstation through the computer, that is, the light detection performance test or application can be performed.
  • the electrolyte solution can be replaced with a 1 mol/L hydrobromic acid solution.
  • the photodetector includes a photoelectrode with gallium nitride-based nanowires.
  • the present disclosure proposes a new type of photoelectrochemical photodetector preparation method, which is based on gallium nitride (GaN)-based materials.
  • GaN gallium nitride
  • the band gap of the material can be adjusted and the band gap of the material can be adjusted at the same time.
  • a general preparation method for preparing a full-spectrum, band-gap adjustable new photoelectrochemical photodetector with ultraviolet-visible-infrared detection wavelength is based on gallium nitride (GaN)-based materials.
  • the appropriate aluminum: gallium or indium: gallium ratio is selected, and the band gap of the prepared GaN-based nanowire is accurately adjusted to obtain high quality of the corresponding wavelength.
  • Single crystal GaN-based nanowires Because the material system is the same, the preparation process of co-catalyst nano-particle modification, photoelectrode encapsulation, and photoelectrochemical system is completely the same. There is no need to change the material system or adjust the process due to the detection wavelength requirements, which greatly reduces the manufacturing cost and has high applicability. Only by adjusting the parameters during the growth process of the nanowires, photodetectors can be produced for different light detection scenarios.
  • the photodetector includes a photoelectrode with gallium nitride-based nanowires.
  • a new type of photoelectrochemical photodetector proposed in the present disclosure is directed to grow p-type doped or n-type doped gallium nitride-based nanowires on a substrate, which has a large specific surface area and is in contact with the interface formed by an electrolyte solution It is conducive to the separation and transportation of photo-generated carriers.
  • the modification of co-catalyst nanoparticles (such as platinum Pt or ruthenium Ru) as the photoelectrode on the GaN-based nanowires optimizes the adsorption and desorption process of the reactants/products, and improves the water reduction of the photoelectrode in the solution.
  • the oxidation reaction rate ensures the photoelectric conversion efficiency, obtains a larger photoelectric response current, and a higher photoresponse degree.
  • the response time can be accurately adjusted according to actual needs.
  • further optimize the design of the photoelectrochemical device change the electrolyte solution environment, and finally realize a new full-spectrum photoelectrochemical photodetector with high response, high sensitivity, fast response, economical and environmental protection, and self-powered (no additional power required), replacing the performance
  • the poor traditional MSM photodetector makes up for the blank of photoelectrochemical photodetector using gallium nitride-based materials.
  • the pioneering application of gallium nitride-based nanowires in the research of photoelectrochemical photodetectors is of great significance in this disclosure.
  • FIG. 8A is a schematic diagram of a solar-blind ultraviolet photoelectrochemical photodetector GaN-based nanohole array in an embodiment of the present disclosure
  • FIG. 8A is a schematic diagram of a solar-blind ultraviolet photoelectrochemical photodetector GaN-based nanohole array in an embodiment of the present disclosure
  • the photodetector includes a photoelectrode
  • the photoelectrode includes a substrate 810
  • the GaN-based nanohole 840 array 830 formed on the surface of the 810 constitutes the basic structure 800 of the photocathode of the novel photoelectrochemical photodetector proposed in the present disclosure.
  • the nanopore structure can be a regular arrangement, such as a nanopore structure prepared by directional growth, or it can also include an irregular, disordered nanopore structure.
  • the so-called “regular” can be understood as a nanopore structure. Whether the arrangement is periodic.
  • the gallium nitride-based material can be selected as AlGaN in the present disclosure.
  • AlGaN is only a symbol expression for this material, and does not represent the standard chemical formula of this material.
  • the GaN-based chemical formula can be one of B x Al y Galxy N or In x Al y Galxy N, 0 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 1. That is, the gallium nitride-based material may be AlGaN or InGaN, or a gallium nitride-based material such as AlInGaN, which is not limited in the present disclosure.
  • the photoelectrode mentioned in the claims in the present disclosure can be a photocathode or a photoanode, and can be specifically distinguished by its doping component (such as magnesium doping or silicon doping), which corresponds to the reduction in the present disclosure. Reaction or oxidation reaction.
  • the present disclosure mainly uses the AlGaN photocathode as an example for description. Those skilled in the art should understand that it is not a limitation on the photoanode, nor is it a limitation on the non-AlGaN photoelectrode.
  • the AlGaN nanohole array grown on the substrate can be conventionally obtained by molecular beam epitaxy (MBE) or metal organic chemical vapor deposition (MOCVD).
  • MBE molecular beam epitaxy
  • MOCVD metal organic chemical vapor deposition
  • Chemical vapor deposition, halide vapor phase epitaxy, pulsed laser deposition and other methods are used for preparation, which are not specifically limited in this disclosure.
  • MOCVD metal organic chemical vapor deposition
  • n-type doped AlGaN nanohole arrays on the surface of the substrate.
  • ordinary oxide and nitride nanomaterials such as gallium oxide nanostructures
  • the band gap can be changed with the doping of the composition, specifically:
  • Eg is the semiconductor forbidden band width, corresponding to different absorption wavelengths.
  • the band gap of the prepared photoanode can be precisely adjusted to achieve light absorption in the solar-blind ultraviolet band.
  • the AlGaN nanopores with high crystal quality prepared in the present disclosure can be p-type doped materials, specifically, silicon Si atoms can be doped, and they move to the electrolyte solution/semiconductor interface as electrons during the subsequent photoelectrochemical reaction process. It will have any impact on AlGaN nanomaterials or structures. Compared with oxide nanomaterials (such as gallium oxide nanostructures) that have not yet been realized, the stability is very high.
  • the prepared AlGaN nanopores of the present disclosure may be p-type doped materials, specifically, magnesium Mg atoms may be doped in order to prepare them for use as a photocathode. It should be noted that in the structure of the photoanode, a protective layer of a certain thickness needs to be deposited on the surface of the photoanode to prevent it from being corroded by photo-generated holes during the photodetection process.
  • the AlGaN nanohole 840 may be a cylindrical hole, a prismatic or other regular hole, or a curved shape or other irregular hole, and the nanohole 840 may be a cylindrical hole.
  • the diameter of the nanopore 840 is 0.1 ⁇ m-5 ⁇ m, and the optional diameter is 2 ⁇ m; its depth is 50 nm-600 nm, and the optional depth is 200 nm. This makes the specific surface area of the nanopore 840 array larger, and at the same time increases the specific surface area of the photodetection reaction.
  • the pore size of the nanopore 840 exceeds 500 nm, which is far beyond the design size of conventional nanopores, and is not considered a nanoscale structure in a certain sense.
  • This size design can prevent the bubbles generated in the subsequent photodetection process from adhering to the inner surface of the nanopore 840 to cause difficulty in mass transfer of the solution.
  • the large-diameter nanopore design is likely to cause unstable performance such as short circuits, and is used in the field. There is no such a large-diameter nanopore design research in China, which will hinder those skilled in the art from implementing this solution. Therefore, this is a breakthrough design scheme in the field, which is beyond the imagination of those skilled in the art.
  • the filling degree of the AlGaN nanohole array can be defined by patterning conditions, the distance between adjacent nanoholes is 0.1 ⁇ m-5 ⁇ m, and the optional distance is 2 ⁇ m. This makes the specific surface area of the nanopore array larger, and at the same time increases the specific surface area of the photodetection reaction.
  • the substrate 810 includes a sapphire substrate, a gallium nitride substrate, a gallium oxide substrate, a silicon carbide substrate, a silicon substrate, or a thin film of GaN-based material.
  • the optional substrate is a sapphire substrate, and in the embodiment of the present disclosure, the substrate material may be aluminum oxide Al 2 O 3 or the like.
  • the GaN-based nanohole array is an n-type GaN-based nanohole array
  • the surface of the GaN-based nanohole array of the photoelectrode further includes a protective layer covering the surface of the nanohole array.
  • the thickness of the protective layer is less than or equal to 10 nm to protect
  • the layer material includes at least titanium dioxide.
  • the protective layer is used to prevent the photo-corrosion phenomenon of the nanoholes.
  • the corresponding p-type gallium nitride-based nanoholes in the present disclosure for example, AlGaN or InGaN nanoholes, etc., it is not limited here, and is subject to the protection scope defined by the claims), which can be used as the photoelectricity in the present disclosure.
  • the photocathode of the chemical photodetector (corresponding to the gallium nitride-based nanowire photocathode in the foregoing embodiment).
  • it is optional to directly modify the cocatalyst nanoparticles on the surface of the p-type nanopore, and it is not necessary to modify the cocatalyst
  • the nanoparticles previously formed at least one protective layer on the surface of the nanopore, which will not be repeated here.
  • an AlGaN single crystal film with stable and high crystal quality can be epitaxially formed on the substrate 810, which is beneficial to the preparation of the nanohole array in the next step.
  • a buffer layer 820 is further included between the substrate 810 and the AlGaN nanohole array 830.
  • the buffer layer 820 includes at least three intermediate layers, and the material of the buffer layer includes aluminum nitride. . Since the crystal lattices of the substrate 810 and the AlGaN nanohole array 830 are not matched, adding a buffer layer 820 between the two is beneficial to obtain a stable and high-quality AlGaN single crystal film during the preparation process, which is beneficial to the next step Preparation of nanopore arrays.
  • the buffer layer 820 includes at least three intermediate layers.
  • the first intermediate layer formed on the substrate 810 has a thickness of 3 ⁇ m and is used as a nucleation layer; the first intermediate layer formed on the first intermediate layer
  • the above-mentioned multiple intermediate layers are not shown in the drawings.
  • composition of the multi-layer intermediate layer is conducive to the formation of a smoother surface of the third intermediate layer (that is, the surface of the buffer layer 820), so that a stable and high-quality AlGaN single crystal film can be obtained during the preparation process, which is beneficial to the next step of nanopores. Preparation of the array.
  • a smoother surface of the third intermediate layer that is, the surface of the buffer layer 820
  • a stable and high-quality AlGaN single crystal film can be obtained during the preparation process, which is beneficial to the next step of nanopores.
  • Preparation of the array Preparation of the array.
  • the corresponding p-type gallium nitride-based nanoholes in the present disclosure for example, AlGaN or InGaN nanoholes, etc., it is not limited here, and is subject to the protection scope defined by the claims), which can be used as the photoelectricity in the present disclosure.
  • the photocathode of the chemical photodetector (corresponding to the gallium nitride-based nanowire photocathode in the foregoing embodiment), correspondingly, the gallium nitride-based nanopore structure can be formed directly on the surface of the substrate without considering the The above-mentioned buffer layer structure is added between the nanopore structure and the substrate.
  • the surface of the AlGaN nanohole array is further covered with a protective layer 870, the thickness of the protective layer 870 is less than or equal to 10 nm, and the optional thickness dimension is 2 nm.
  • the protective layer may be an amorphous titanium dioxide TiO 2 protective layer covering the entire surface of the AlGaN nanohole array, including the inner surface of the nanoholes, to prevent the AlGaN material from being rich in holes during the photodetection process. The photo-corrosion effect occurs under the set conditions, affecting the overall performance of the photodetector.
  • the photoanode further includes co-catalyst nanoparticles 850 distributed on the surface of the protective layer.
  • the co-catalyst nanoparticles 850 are metal particles active in the water redox reaction.
  • the material of the metal particles includes platinum. , Iridium, iron, cobalt, nickel or ruthenium, etc. and their multiple alloys, the alloy is the use of two metals at the same time, such as RuFe, RuCo, etc.
  • ruthenium can be selected as the preparation choice of the co-catalyst nanoparticles, and the diameter size of the co-catalyst nanoparticles can be 0.1nm-1000nm, and can be 2nm for better and more modification in the nanopore array.
  • the co-catalyst nanoparticles distributed on the nanohole array can make the AlGaN nanohole array have a stronger water oxidation reaction, so that the photodetector has a stronger photoresponse and a faster photoresponse speed.
  • the surface of the AlGaN nanohole array further includes a first region 860 that is not covered with the protective layer 870, and the first region 860 is disposed outside the nanohole region.
  • the first area is formed on the surface of the nanohole array and does not overlap with the area where the nanoholes are located, so as to prevent the occurrence of short circuits, and also makes the lead electrode more stable and effective.
  • the first area 860 includes a dot-welded indium ball, which is used to form a conductive area of the photoanode, and is used to draw the photoanode.
  • a dot-welded indium ball By spot welding indium balls, a conductive area in ohmic contact with the surface of the nanohole array can be formed on the first area 860.
  • the conductive area can be a square area of 2mm ⁇ 2mm, which can achieve better conductive characteristics and current stability, and can be fixed at the same time
  • the wire leads to the electrode to form a photoanode.
  • the photoelectrochemical photodetector further includes: an electrolyte solution in contact with the photoanode, and a reference electrode and a counter electrode in contact with the electrolyte solution, A certain distance is maintained between the reference electrode, the counter electrode, and the photoanode, where the distance is approximately equal to 0.01 mm; wherein, the reference electrode, the counter electrode, and the photoanode are respectively connected to an electrochemical workstation with current monitoring function. Therefore, it basically constitutes a photoelectrochemical photodetector based on a simple water oxidation reaction as a photoelectric reaction mechanism. The preparation conditions are simple, the purity requirements are low, and the working process has almost no effect on the electrode materials.
  • the electrolyte solution includes an acidic or neutral electrolyte solution
  • the neutral electrolyte solution is sodium sulfate
  • the acidic electrolyte solution includes phosphoric acid buffer or hydrobromic acid
  • the concentration of the electrolyte solution is 0.01 mol/L to 5 mol/L
  • the present disclosure can choose weak acid electrolyte solutions such as 0.5mol/L hydrobromic acid solution; reference electrodes are silver/silver chloride (Ag/AgCl) electrodes, etc.; counter electrodes include platinum (Pt) electrodes, carbon (C) electrodes, etc. ,
  • the specific structure can be made into a mesh electrode and other forms.
  • a complete new solar-blind ultraviolet photoelectrochemical photodetector is formed by the above-mentioned components and the above-mentioned AlGaN nanohole array photoanode together.
  • the new solar-blind ultraviolet photoelectrochemical photodetector can further optimize the photodetection response by modifying the co-catalyst nanoparticles.
  • the product includes the above-mentioned photodetector and a packaging structure for packaging the photodetector.
  • the packaging structure It includes a housing structure covering the photodetector to encapsulate it; an optical window is opened on one surface of the housing structure, and a light-transmitting surface matched with the optical window for sealing the optical window is provided.
  • the light-transmitting surface is equipped with an AlGaN nanohole array
  • the surface of the photocathode is set at a certain distance, where the distance is approximately equal to 0.01mm.
  • the distance can be selected to be 0.2cm, which is used for solar-blind ultraviolet light irradiated on the photoanode through the light-transmitting surface.
  • the catalyst nanoparticles are distributed AlGaN nanohole array. The structure is simple, and the preparation materials are easy to obtain.
  • the light-transmitting surface includes a transparent material with limited ability to absorb solar-blind ultraviolet light;
  • the shell structure includes a shell structure formed of a polytetrafluoroethylene material.
  • one surface of the housing structure is provided with a sealable/openable injection hole, an exhaust hole, and at least three electrode holes for setting a photocathode, a reference electrode, and a counter electrode, respectively.
  • the manufacturing process has low requirements and low cost.
  • the present disclosure proposes a new type of solar-blind ultraviolet photoelectrochemical photodetector product, because the photoelectrochemical photodetector has simple structure, low manufacturing process requirements, low cost, and the product has a very simple packaging structure, which is convenient for practical applications. It is easy to produce on a large scale, and realizes the commercialization of photoelectrochemical photodetectors.
  • Another aspect of the present disclosure provides a method for preparing a solar-blind ultraviolet photoelectrochemical photodetector, which is applied to prepare the above-mentioned photodetector, as shown in FIG. 9 for a method for preparing a solar-blind ultraviolet photoelectrochemical photodetector in an embodiment of the present disclosure.
  • the preparation method includes:
  • AlGaN nanohole array on the surface of the substrate; specifically, as an embodiment of the present disclosure, metal organic chemical vapor deposition (MOCVD) may be selected to prepare it, and triethyl boron may be selected in the preparation process Alkane (TEB), trimethylaluminum (TMAl), trimethylgallium (TMGa), and ammonia (NH 3 ) are used as growth precursors to provide B, Al, Ga, and N sources, and Si is used as an n-type doping source, H 2 is used as a carrier gas.
  • TEB Alkane
  • TMAl trimethylaluminum
  • TMGa trimethylgallium
  • NH 3 ammonia
  • gallium nitride-based materials the corresponding AlGaN materials can be obtained by controlling the composition ratios of different aluminum and gallium.
  • AlGaN materials with different composition ratios can make the energy band of the material itself correspond to different, and the band gap varies with the doping composition. Change to correspond to different light absorption wavelengths.
  • the composition of aluminum in the gallium nitride-based material can be controlled, and the modification and control of the composition ratio is very simple and precise at the same time. Therefore, it can better adapt to the preparation of nanomaterials corresponding to the broad spectrum light wavelength, and can also accurately control the formation of nanomaterials adaptable to solar-blind ultraviolet light wavelengths, which simplifies the preparation process.
  • silicon is used to dope the formed AlGaN nanohole array to obtain an n-type doped AlGaN nanohole array that is more suitable for photoanodes, which is beneficial to improve the water oxidation reaction of the photodetector and improve the photocurrent response intensity and speed.
  • S920 Modifying the promoter nanoparticles on the nanoholes of the AlGaN nanohole array; specifically, as an embodiment of the present disclosure, optical deposition or atomic layer deposition (Atomic Layer Deposition) is used on the nanoholes of the AlGaN nanohole array.
  • ALD ALD
  • electrodeposition method chemical loading method
  • impregnation method chemical loading method
  • the photoanode functional layer is prepared on the surface of the substrate to ensure a higher crystal quality AlGaN nanohole array at a lower cost; a buffer layer is formed between the substrate and the AlGaN nanohole array to improve the film-forming effect of the AlGaN film.
  • the formation of high crystal quality AlGaN nanohole arrays is ensured; the surface of the AlGaN nanohole arrays is covered with an amorphous protective layer, which can prevent the photoanode from being photo-corrosive during the photodetection process, affecting the overall photodetection performance of the photodetector;
  • the modification of the promoter nanoparticles on the surface of the protective layer further increases the water oxidation reaction rate, thereby improving the ultraviolet light response.
  • FIG. 10A a schematic diagram of the first stage of the AlGaN nanohole array preparation process in the solar-blind ultraviolet photoelectrochemical photodetector preparation method in an embodiment of the present disclosure
  • an AlGaN nanohole array is formed on the surface of the substrate.
  • pre-annealing the substrate 810 forming a buffer layer 820 on the pre-annealed substrate 810; according to an embodiment of the present disclosure, before growth, the sapphire substrate is pre-treated at 1200°C in an H 2 -NH 3 environment , 5 minutes of high temperature annealing, making the surface of the sapphire substrate cleaner and smoother, and more suitable as the substrate of the AlGaN nanohole array.
  • the AlGaN nanohole array can be formed on the surface of the buffer layer 820 of the substrate 810 by metal organic chemical vapor deposition, MOCVD, or molecular beam epitaxy (MBE), and the specific method is not limited.
  • MOCVD metal organic chemical vapor deposition
  • MBE molecular beam epitaxy
  • an AlGaN film 831 is pre-formed on the surface of the buffer layer 820.
  • a 200nm AlGaN film is grown on the buffer layer at a temperature of 1150°C.
  • the thin film 831 is operated to form a nanohole array. By forming the thin film 831 first, the high crystal quality for forming the nanohole array can be guaranteed.
  • forming a buffer layer 820 on a pre-annealed substrate 810 includes: including at least two intermediate layers (not shown) on the buffer layer 820; forming a second layer on the substrate 810 under a first condition An intermediate layer, a second intermediate layer is formed on the first intermediate layer under the second condition; and a third intermediate layer is formed on the second intermediate layer under the third condition.
  • the buffer layer 820 is formed on the pre-annealed sapphire bottom 810, and MOCVD can be used as the preparation method, including: AlN is used as the buffer layer preparation material, first, TMAl and NH 3 are heated at a temperature of 850°C-950°C.
  • the volume flow rate of 3 ⁇ m is formed on the sapphire substrate 810 to form a low-temperature AlN nucleation layer with a thickness of 3 ⁇ m as the first intermediate layer; under the second condition at a temperature of 850-1250°C, An AlN spacer layer with a thickness of up to 100 nm is formed on the first intermediate layer as the second intermediate layer; a high temperature AlN with a thickness of 1 ⁇ m is formed on the second intermediate layer under the third condition of 1250°C and V/III of 180
  • the template layer serves as the third intermediate layer.
  • the structure of the multi-layer intermediate layer is beneficial to form a smoother surface of the third intermediate layer (that is, the surface of the buffer layer 820), so that a stable and high-crystalline AlGaN nanohole array can be obtained during the preparation process.
  • forming an AlGaN nanohole array on the surface of the buffer layer of the substrate includes: forming an AlGaN film on the buffer layer under the fourth condition; etching the film to form an AlGaN nanohole array.
  • a cylindrical nanohole array is prepared by micro-nano processing technology, wherein The AlGaN thin film may be formed on the third intermediate layer.
  • the described fourth conditions include any preparation conditions used in the following steps: using photoresist of model S1813 as the etching sacrificial layer 910 in the subsequent etching process, and the coating rate is controlled At 4000 revolutions/min for 30 seconds, a photoresist sacrificial layer 910 with a thickness of about 1.2 ⁇ m is formed; as shown in FIG.
  • a circle with a diameter of 2 ⁇ m is drawn on the mask 320, and the distance between adjacent patterns is 2 ⁇ m, forming Array structure, post-baking temperature is controlled at 115°C, time is 90 seconds; use Optical Aligner-SUSS MABA6 UV lithography machine for pattern definition, use contact exposure, pitch 60 ⁇ m, exposure time is 7.5 seconds (step3); then develop in AZ300MIF The pattern is exposed by developing for 50 seconds in the liquid, so that a circular pattern 911 defined by the exposed and developed area corresponding to the position of the nanopore is formed on the sacrificial layer 910, and is washed in clear water. As shown in FIG.
  • an inductively coupled plasma can be optionally used to etch the AlGaN film to first realize the nanopore structure 930 on the sacrificial layer 910.
  • ICP inductively coupled plasma
  • FIG. 10E the AlGaN film grown by MOCVD is etched by Oxford ICP 180, and the etched area is a circular pattern 911 defined by ultraviolet lithography.
  • the etching gas is Cl 2 /BCl 3 /Ar, the gas flow is controlled at 10/25/25 sccm, the temperature is 50 °C, the cavity pressure is 6 mTorr, the ICP power is 450 W, and the radio frequency power is 100 W.
  • the sample is not placed before the etching, and the above process parameters are used for cavity operation to ensure the gas environment of the cavity.
  • the etching time is controlled to be 2.5 minutes to form AlGaN nanoholes with a depth of 200 nm.
  • the selection ratio of AlGaN to S1813 photoresist is 1:2, and the remaining thickness of S1813 photoresist after etching is about 800 ⁇ m (step 5).
  • Use acetone, isopropanol, and water to wash away the remaining photoresist on the sample to complete the preparation of the nanohole array, as shown in FIG. 10F.
  • the AlGaN nanohole array 830 may be formed on the surface of the buffer layer 820 of the substrate, including: forming silicon dioxide islands on the surface of the buffer layer 820, and forming silicon dioxide islands on the surface of the buffer layer 820 where the silicon dioxide islands are formed.
  • the islands may be protrusions or regions formed on the surface of the buffer layer 820, which are formed by special processing techniques or special materials. Specifically, it is optional to form small silicon dioxide islands on the surface of the third intermediate layer of the buffer layer 820 by means of micro-nano processing technology, and then through molecular beam epitaxy (MBE) or metal organic chemistry.
  • MBE molecular beam epitaxy
  • the vapor deposition method directly grows the film on the surface of the third intermediate layer where the silicon dioxide islands have been formed. Since the silicon dioxide islands have an obstructive effect on the growth of the film, the location of the silicon dioxide islands does not form a thin film material. Finally, the AlGaN nanohole array 830 is formed on the surface of the buffer layer 820.
  • the material of the above-mentioned island may be silicon dioxide, titanium dioxide, silicon nitride, or metal. The above description of the silicon dioxide island is not a limitation on the material of the island.
  • modifying the promoter nanoparticles on the nanopores of the AlGaN nanopore array includes: forming an amorphous protective layer covering the surface of the nanopore array on the surface of the AlGaN nanopore array; modifying the promoter on the surface of the protective layer Nano particles.
  • the 2nm thick amorphous TiO 2 protection can be deposited by atomic layer deposition (ALD).
  • the layer (a-TiO 2 ) 870 prevents the AlGaN material from photo-corrosion under the condition of hole enrichment.
  • the deposition process uses tetrakis (dimethylamino) titanium (IV) TEMAT and water as precursors, and the precursor containers are kept at 65°C and 25°C, respectively. Co-deposition for 60 cycles. Each cycle includes the process of introducing titanium precursor for 0.1s, N 2 purging for 10 seconds, water vapor for 0.1s, N 2 purging for 10 seconds, and forming a covering nanohole array surface on the surface of the AlGaN nanohole array by atomic layer deposition.
  • the amorphous protective layer 870 is used to protect the nanohole array from hole corrosion. Because of its tunnel conduction effect, it has good conductivity and will not affect the detection performance.
  • the photodeposition method can be used to modify the promoter nanoparticles 850 on the surface of the protective layer 870, Add 100 ⁇ L of 20 mg/mL ruthenium chloride (RuCl3) solution to 20 mL of deionized water, and place the prepared a-TiO 2 /n-AlGaN nanohole array in it, and simultaneously measure the a-TiO 2 /n-AlGaN nanoholes The array applies ultraviolet light corresponding to the band gap.
  • RuCl3 ruthenium chloride
  • the a-TiO 2 /n-AlGaN nanohole array Due to the semiconductor photoelectric effect, the a-TiO 2 /n-AlGaN nanohole array generates photo-generated electron-hole pairs after absorbing photons. Then the photogenerated electrons diffuse to the surface of the nanopore. Because the energy of the photogenerated electrons is greater than the reduction potential of the ruthenium ion Ru 3+ in the solution, the photogenerated electrons diffused to the surface of the nanopore will be reduced and modified on the surface of the a-TiO 2 /n-AlGaN nanopore array. Ru 3+ , form nano-Ru particles, and the nano-particles can be 2nm.
  • the preparation of a photodetector by using an AlGaN nanohole array modified with cocatalyst nanoparticles as a photoanode includes: forming a first region without a protective layer on the surface of the AlGaN nanohole array, and the first region is provided Outside the nanopore area; spot-welded indium balls are arranged on the first area to form a conductive area of the photoanode, which is used to draw out the photoanode.
  • the first area is formed on the surface of the nanohole array and does not overlap with the area where the nanoholes are located, so as to prevent the occurrence of short circuits, and also makes the lead electrode more stable and effective.
  • a conductive area in ohmic contact with the surface of the nanohole array can be formed on the first area 860.
  • the conductive area can be a square area of 2mm ⁇ 2mm, which can achieve better conductive characteristics and current stability, and can be fixed at the same time
  • the wire leads to the electrode to form a photoanode.
  • the preparation of a photodetector using AlGaN nanopore arrays of modified cocatalyst nanoparticles as a photoanode also includes: arranging a reference electrode, a counter electrode, and a photoanode in an electrolyte solution at a certain interval to prepare a photodetector.
  • the electrode system constitutes a photodetector. Therefore, a photoelectrochemical photodetector based on a simple water oxidation reaction as a photoelectric reaction mechanism is basically constituted.
  • the preparation conditions are simple, the purity requirements are low, and the working process has almost no influence on the electrode materials.

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Abstract

一种光电化学光探测器及其制备方法，制备方法包括：根据光探测器的待探测光波长选择氮化镓基化合物半导体材料组分；根据组分在衬底(110,810)表面上形成氮化镓基纳米线；氮化镓基纳米线上均匀修饰助催化剂纳米颗粒(210,850)；对已修饰助催化剂纳米颗粒(210,850)的氮化镓基纳米线进行封装得到光电极；以及利用光电极制备光电化学光探测器。仅在纳米线生长过程中调整纳米线中组分含量即可生产出应用于不同光探测场景的光探测器。最后采取相同工艺流程制备高响应度、快速反应、经济环保、自供能的新型全波段光电化学光探测器。将氮化镓基纳米线应用于光电化学光探测器的研究中，具有十分重要的意义。

Description

光电化学光探测器及其制备方法 技术领域
本公开涉及光电化学光探测器技术领域，具体涉及一种新型光电化学光探测器及其制备方法。
背景技术
光电探测器(即光探测器)，即捕获光信号并将其转换为电信号的器件，被广泛应用于成像，通信，传感，计算，新兴可穿戴设备和宇宙空间领域探测等领域。光电探测器在军事和国民经济的各个领域有广泛用途。在可见光或近红外波段主要用于射线测量和探测、工业自动控制、光度计量等；在红外波段主要用于导弹制导、红外热成像、红外遥感等方面；紫外波段主要用于火焰探测，导弹警报，臭氧监测和非视距光通信等。
现今的光探测器大都基于简单的金属-半导体-金属(Metal-Semiconductor-Metal，即MSM)结构，MSM结构光探测器在工作时需要施加外部偏压，不仅耗费电力，在响应度及响应速度方面也有待提高；同时，为了满足不同应用需求，MSM结构的光电探测器的研究涉及的材料体系和结构纷乱复杂，没有统一的设计和制备方法，无法适应于大规模生产可应用于各波段光探测器的需要。
发明内容
本公开的一个方面提出了一种光电化学光探测器的制备方法，所述方法包括：根据光探测器的待探测光波长选择氮化镓基材料组分；根据所述组分在衬底表面上形成氮化镓基纳米线；在所述氮化镓基纳米线上修饰助催化剂纳米颗粒；对已修饰助催化剂纳米颗粒的氮化镓基纳米线进行封装得到光电极；以及利用光电极制备光电化学光探测器。
根据本公开的实施例，根据光探测器的待探测光波长选择氮化镓基化合物半导体材料组分，包括：根据下述公式：Eg＝3.42eV+x×2.86eV-x(1-x)×1.0eV确定与待探测光波长对应的在Al xGa l-xN的Al组分；或根据下述公式：Eg＝3.42eV-x×2.65eV-x(1-x)×2.4eV确定与待探测光波长对应的在In xGa l-xN中的In组分，Eg为化合物半导体的禁带宽度，对应不同光波段的吸收波长，通过禁带宽度可以得出对应的吸收波长。
根据本公开的实施例，根据所述组分在衬底表面上形成氮化镓基纳米线，还包括：在衬底上形成纳米孔阵列结构，纳米孔阵列结构的厚度小于等于50nm；在纳米孔中定位填充p型掺杂或n型掺杂的氮化镓基材料形成复合层，以及在复合层的表面上、对应于纳米孔的位置继续形成p型掺杂或n型掺杂的氮化镓基纳米线；或将复合层的纳米孔阵列结构去除以在衬底表面上形成p型掺杂或n型掺杂的氮化镓基纳米线。
根据本公开的实施例，根据所述组分在衬底表面上形成氮化镓基纳米线，还包括：在所述衬底上形成p型掺杂或n型掺杂的氮化镓基薄膜，对所述氮化镓基薄膜进行刻蚀以在所述衬底表面上形成所述p型掺杂或n型掺杂的氮化镓基纳米线。
根据本公开的实施例，根据上述组分在衬底表面上形成氮化镓基纳米线，包括：控制镁或硅的掺杂比例，在衬底上形成相应掺杂比例的p型掺杂或n型掺杂的氮化镓基纳米线。
根据本公开的实施例，在所述氮化镓基纳米线上修饰助催化剂纳米颗粒之前，还包括：当氮化镓基纳米线为n型掺杂时，在氮化镓基纳米线表面制备保护层，所述保护层厚度小于等于10nm。
根据本公开的实施例，在所述氮化镓基纳米线上修饰助催化剂纳米颗粒，包括：将氮化镓基纳米线设置在第一浓度的前驱体水溶液中，同时施加与纳米线能带相应波长的光线照射，以在氮化镓基纳米线表面修饰助催化剂纳米颗粒。
根据本公开的实施例，对已修饰助催化剂纳米颗粒的氮化镓基纳米线进行封装得到光电极，包括：将导线固定贴附在具备已修饰助催化剂纳米颗粒的氮化镓基纳米线的衬底的导电区域上，将导线连同衬底包覆固定、同时露出氮化镓基纳米线以形成封装光电极。
根据本公开的实施例，将导线固定贴附在具备已修饰助催化剂纳米颗粒的氮化镓基纳米线的衬底的导电区域上，包括：在衬底导电区域上刮除氧化层，在刮除了氧化层的导电区域上涂覆液态合金，在导线和导电区域之间、与液态合金位置相对的导线表面上涂覆导电胶。
根据本公开的实施例，利用光电极制备光电化学光探测器，包括：将光电极以及参比电极、对电极以一定间距设置于第二浓度的电解质溶液中 制备为三电极体系，构成光电化学光探测器。
根据本公开的实施例，根据组分在衬底表面上形成氮化镓基纳米线，还包括：在衬底上形成二氧化硅，氮化硅，二氧化钛，纯金属等纳米孔阵列结构，纳米孔阵列结构且其的厚度不超过小于等于50nm；在纳米孔中定位填充氮化镓基材料形成复合层，以及在复合层的表面上、对应于纳米孔的位置继续形成氮化镓基纳米线；或将复合层的二氧化硅纳米孔阵列结构去除以在衬底表面上形成氮化镓基纳米线。
根据本公开的实施例，根据所述组分在衬底表面上形成氮化镓基纳米线，还包括：通过分子束外延法在衬底上形成氮化镓基薄膜，对氮化镓基薄膜进行干法刻蚀以在衬底表面上形成氮化镓基纳米线。
附图说明
图1A是本公开一实施例中AlGaN纳米线的示意图；
图1B是本公开一实施例中AlGaN纳米线的扫描电子显微镜图；
图2是本公开一实施例中AlGaN纳米线中修饰助催化剂纳米Pt颗粒的示意图；
图3A是本公开一实施例中AlGaN纳米线光阴极的封装剖面示意图；
图3B是本公开一实施例中AlGaN纳米线光阴极的封装示意图；
图4是本公开一实施例中新型日盲紫外光电化学光探测器的制备示意图；
图5是本公开一实施例中新型日盲紫外光电化学光探测器的产品示意图；
图6是本公开一实施例中光电化学光探测器的制备方法流程示意图；
图7是本公开一实施例中光电化学光探测器的光谱简单对照图；
图8A是本公开一实施例中日盲紫外光电化学光探测器AlGaN纳米孔阵列的示意图；
图8B是本公开一实施例中日盲紫外光电化学光探测器已修饰助催化剂纳米颗粒的AlGaN纳米孔阵列的示意图；
图9是本公开一实施例中日盲紫外光电化学光探测器制备方法流程示意图；
图10A是本公开一实施例中日盲紫外光电化学光探测器制备方法中 AlGaN纳米孔阵列制备流程一阶段示意图；
图10B是本公开一实施例中日盲紫外光电化学光探测器制备方法中AlGaN纳米孔阵列制备流程一阶段示意图；
图10C是本公开一实施例中日盲紫外光电化学光探测器制备方法中AlGaN纳米孔阵列制备流程一阶段示意图；
图10D是本公开一实施例中日盲紫外光电化学光探测器制备方法中AlGaN纳米孔阵列制备流程一阶段示意图；
图10E是本公开一实施例中日盲紫外光电化学光探测器制备方法中AlGaN纳米孔阵列制备流程一阶段示意图；
图10F是本公开一实施例中日盲紫外光电化学光探测器制备方法中AlGaN纳米孔阵列制备流程一阶段示意图；
图10G是本公开一实施例中日盲紫外光电化学光探测器制备方法中AlGaN纳米孔阵列制备流程一阶段示意图；
图10H是本公开一实施例中日盲紫外光电化学光探测器制备方法中AlGaN纳米孔阵列制备流程一阶段示意图。
具体实施方式
光电化学光探测器由光电化学反应衍变而来。以p型半导体为例，光电化学反应即半导体受光照产生光生电子和空穴，电子于半导体电极发生还原反应，空穴流经外电路至对电极发生氧化反应(n型半导体则相反)。该过程中所测试的性能指标光/暗电流比，响应时间与光照强度，光波长直接相关，并以此逐步衍生出专用于光探测的光电化学装置。在光电化学研究领域，绝大部分研究集中于可见光条件下的光电催化氧化还原反应，利用光电化学做光探测器的研究较少，而对于红外波段、紫外波段的光电化学光探测器研究极少，这可以说是一个全新的方向。具体而言，光电化学催化侧重于对化学反应机理的研究，例如研究半导体材料在光电催化反应过程中产生的氢气量，如何提高产氢量以及如何设计反应位点。光电化学光探测器主要研究在上述光电化学反应过程中产生的光暗电流信号，用以反应探测光的相关参数，进而实现各类光电探测功能。
另外，三五族氮化物半导体材料的研究方向主要集中于发光二极管(Light Emitting Diode，即LED)及功率器件，且由于例如分子束外延法 (Molecular Beam Epitaxy，即MBE)制备氮化物成本极高，利用氮化物纳米材料进行光电化学催化研究尚处于起步阶段，更不用谈及利用三五族氮化物材料做光电化学光探测器。一般，紫外光探测(非日盲波段)选取的是化学法制备的粉末样品(如氧化锌ZnO，二氧化钛TiO 2等)，因晶体质量很差，缺陷多，光生电子空穴对易复合，直接导致光探测性能差。本公开创造性提出了一种GaN基纳米线/纳米孔结构，应用于光电化学光探测器，克服了本领域的技术难题，并且取得了突破性的技术效果。
为使本公开的目的、技术方案和优点更加清楚明白，以下结合具体实施例，并参照附图，对本公开进一步详细说明。
实施例1：
本公开的一个方面提出了一种新型日盲紫外光电化学光探测器，图1A是本公开一实施例中AlGaN纳米线的示意图。该新型日盲紫外光电化学光探测器包括光阴极，光阴极包括衬底110，还包括生长在衬底110表面的AlGaN纳米线120，从而构成本公开所提出的新型光电化学光探测器光阴极的基本结构100。其中，GaN基纳米线包括n型GaN基纳米线和p型GaN基纳米线。本领域技术人员应当理解，该纳米线结构可以是规则性排列，例如定向生长制备的纳米线结构，也可以包括非规则排列的纳米线结构，所谓“规则”可以理解为纳米线的排列是否具有周期性；相应地，所谓“非规则”可以理解为纳米线的排列是否不具有周期性，也可以理解为纳米线的长度、直径，任意相邻纳米线之间的间距，纳米线的生长角度(相对于衬底)不一致，无规律可循。另外，该氮化镓基材料在本公开中可选为AlGaN，AlGaN仅仅是为本材料的一个符号表达，不代表本材料的标准化学式，具体地，GaN基材料的化学式可选Al xGa l-xN，B xAl yGa l-x-yN或In xAl yGa l-x-yN中的一种，0≤x＜1，0≤y≤1。即，该氮化镓基材料可以是AlGaN或InGaN，亦或是AlInGaN等氮化镓基材料，本公开并不对此做任何限制。
在本公开中权利要求书中所提及的光电极，可以是光阴极或光阳极，具体可以以其掺杂组分(例如镁掺杂或硅掺杂)为区分，对应于本公开中还原反应或氧化反应。为清楚地表达本公开中光电极的作用，本公开主要以AlGaN光阴极作为示例进行描述。本领域技术人员应当理解，其并非 是对光阳极的限定，也并非是对非AlGaN光电极的限定。作为本公开一实施例，生长在衬底110表面的AlGaN纳米线120，可以通过分子束外延法(Molecular Beam Epitaxy，即MBE)或有机金属化学气相沉积法(Metal Organic Chemical Vapor Deposition，即MOCVD)，常规化学气相沉积法，卤化物气相外延或脉冲激光沉积等方法进行制备，本公开中具体不作限制。同时，为更加清楚地表达本公开的AlGaN纳米线120，以下主要以分子束外延法(MBE)为基本制备方法来进行介绍。
本公开的AlGaN纳米线120因其相较于普通的氧化物和氮化物纳米材料(例如氧化镓纳米结构)，稳定性高，晶体质量高，带隙高度匹配可调等优势，能够保证在日盲光照射下具有优良的水还原性能，反映为优异的光探测性能。另外，对于Al xGa l-xN材料，其带隙可以随组分掺杂改变，具体而言：
Eg＝3.42eV+x*2.86eV-x(1-x)*1.0eV...........................(1)
其中Eg为半导体禁带宽度，对应不同光波段的吸收波长。
因此，根据公式(1)，通过控制制备过程中的Al、Ga组分占比，即可精确调控制备成的光阴极带隙，实现日盲紫外波段的光吸收。相应地，对于B xAl yGa l-x-yN或In xAl yGa l-x-yN(0≤x＜1，0≤y≤1)等中的氮化镓基材料，其对应的波长计算公式可以相应进行变换，具体以实际制备的需要为准，在本公开中不对此作限制。
另外，本公开制备的高晶体质量的AlGaN纳米线可以为p型掺杂材料，具体而言，可以掺入Mg原子。当p型半导体与水溶液接触时，会发生电子交换，最终结果是水-半导体体系的费米能级相同，p型半导体能带下弯，导致电子向接触面移动，表面富电子，在光探测过程中不会对AlGaN纳米材料或结构造成任何影响，相对于尚未能实现p型掺杂的氧化物纳米材料(例如氧化镓纳米结构)，稳定性非常高，既可以作为光阴极。相应地，作为本公开中的另一实施例，也可以通过改为n型掺杂的AlGaN纳米线，并施以一定保护层将其作为光阳极。
作为一可选实施例，衬底110包括导电衬底，导电衬底包括标准低阻的硅衬底，例如具有整体导电特性的硅片，硅衬底尺寸可选为1cm×1cm，具体尺寸依据光电极的尺寸需要，本公开中对此不作限制。
作为一可选实施例，硅衬底包括n型硅衬底，n型硅衬底为n型任意晶面硅衬底，例如Si(111)面衬底；还包括p型硅衬底，p型硅衬底为p型任意晶面硅衬底，例如Si(100)面衬底。可以在该衬底上稳定形成高晶体质量的GaN基纳米线。具体地，硅衬底只是本公开中一可选衬底，在本公开中衬底包括任何可以导电的固态衬底(可以理解为表面生长有导电层的基板)，包括金属、导电硅和硅上面覆盖金属薄膜的衬底、碳化硅、氮化镓、氧化镓、金刚石、石墨烯、ITO(氧化铟锡)材料，或者其他固态半导体导电基板或者覆盖有导电层的任意固态衬底材料。
图1B是本公开一实施例中AlGaN纳米线的扫描电子显微镜图。作为一可选实施例，AlGaN纳米线120的单个纳米线平均长度为10nm-5000nm，可选为300nm-400nm长度范围；单个纳米线平均直径为5nm-5000nm，可选为60nm-80nm。使得该纳米线的比表面积更大，同时增加光探测过程中氧化还原反应的速率。
作为一可选实施例，AlGaN纳米线120的覆盖度(或者填充率)为1％-99％，可选为70％左右。覆盖密度相当于纳米线的上表面面积总和与所占据整个衬底表面面积的百分比，用以反应纳米线之间的间距、单位表面上的纳米线数量等。
作为一可选实施例，光电极包括由n型GaN基纳米线形成的光阳极和p型GaN基纳米线形成的光阴极，还包括分布于其表面的助催化剂纳米颗粒。
作为一可选实施例，GaN基纳米线为n型GaN基纳米线，光电极表面还包括形成于n型GaN基纳米线表面的一层保护层，保护层厚度小于等于10nm。用于防止GaN基纳米线光腐蚀现象发生，保护层为二氧化钛(TiO 2)或者其他可以起保护作用的材料。
图2是本公开一实施例中AlGaN纳米线中修饰助催化剂纳米Pt颗粒的示意图。作为一可选实施例，在图2中所示的修饰助催化剂纳米颗粒AlGaN纳米结构200中，光阴极还包括修饰于AlGaN纳米线120中纳米线表面的助催化剂纳米颗粒210，助催化剂纳米颗粒210的尺寸为0.1nm-1000nm。相应地，对于本公开中对应的n型氮化镓基纳米线(例如AlGaN或InGaN纳米线等，在此不作限制，依照权利要求书所限定的保 护范围为准)，可以作为本公开中光电化学光探测器的光阳极，该n型纳米线在修饰助催化剂纳米颗粒之前，可以选择在纳米线表面形成至少一保护层，该保护层可以是上述的二氧化钛等材料所制备的保护层，用于防止n型GaN基纳米线光腐蚀现象发生，此处不再赘述。
在AlGaN纳米线120的纳米线上利用光沉积法，或原子层沉积法(Atomic Layer Deposition，ALD)、电沉积法(化学负载方法)、浸渍法(化学负载方法)将助催化剂纳米颗粒修饰于纳米线表面。
具体地，当采用与AlGaN纳米线120带隙对应的日盲紫外光照射处于光沉积过程中的AlGaN纳米线120，在半导体光电效应的情况下，AlGaN纳米线120的纳米线吸收光子后产生光生电子-空穴对。随后光生电子向纳米线表面扩散，因光生电子能量大于溶液中的助催化剂前驱体基团的还原电位，扩散至纳米线表面的光生电子将还原修饰于AlGaN纳米线表面的助催化剂前驱体基团，从而在AlGaN纳米线120的纳米线表面形成修饰的纳米颗粒210。其颗粒尺寸直径可以为0.1nm-1000nm，可选5nm，并修饰于纳米线表面。在后续的光探测过程中，助催化剂使该体系还原反应活性显著增强，加快反应速率，提高光响应性能。
作为一可选实施例，助催化剂纳米颗粒210包括水还原反应活性的金属颗粒。作为一可选实施例，金属颗粒材料包括铂、铼、钯、铱、铑、铁、钴或镍等，或其多元合金，合金即为同时使用两种金属，比如RuFe，RuCo。本公开中可选为铂(Pt)。助催化剂纳米颗粒210需要对水分子及还原产物有适当的吸附能，具有较高的水还原活性，使得还原反应更强烈，光探测过程中光电流信号更强。相应地，若对于光阳极而言，其助催化剂纳米颗粒则可以包括具水氧化反应活性的金属颗粒，包括铱、铁、钴、镍或钌等，或其多元合金，相应地具有较高的水氧化活性，氧化反应更加强烈。本领域技术人员应当理解，在本实施例中关于助催化剂修饰材料的介绍，并非是对本公开保护范围的限制，而仅仅是本公开的实施方式。
图3A是本公开一实施例中AlGaN纳米线光阴极300的封装剖面示意图；图3B是本公开一实施例中AlGaN纳米线光阴极300的封装示意图。作为一可选实施例，为成功封装上述的光阴极的AlGaN纳米线120，光电化学光探测器还包括：设置于衬底110导电区域的导线310，将导线310、 光阴极进行包覆固定、露出光阴极的AlGaN纳米线120的固化包覆结构320。如图3B所示，固化包覆结构320的固化结构表面可以形成一固化窗口321，通过固化窗口321将AlGaN纳米线120露出，使得在后续光探测过程中，外界施加的日盲紫外光直接通过固化窗口321照射到AlGaN纳米线120上。此处可选的衬底110材料可以是p型Si(100)面硅片，面积尺寸1cm×1cm，厚度在0.01mm到1000mm之间选择此时导电区域纳米线设置在衬底110的背面，如图3A所示。导线设置于衬底背面。其中，导电区域可以是硅片的背面或者正面利用金刚石笔刮除纳米线之外的某个区域，具体在本公开中不作限制。
作为一可选实施例，导线310材料包括金、银、铜等，导线310的尺寸与衬底110的尺寸匹配选取。例如，可以选择约1.2cm宽，5cm长的导线310，其材料可以是铜Cu。也可以使用导电铜胶带。
作为一可选实施例，固化包覆结构320的材料包括可固化、并在固化后具备绝缘特性的液态材料，固化包覆结构320为环氧树脂等，起到包裹及绝缘效果。
作为一可选实施例，在导线310与衬底110之间还包括设置于衬底导电区域的液态合金330以及设置于导线310表面、与液态合金330相对的导电胶340。作为一可选实施例，液态合金330为液态镓铟(GaIn)合金，液态镓铟(GaIn)合金纯度为90～99.99999％之间可选；导电胶340为银胶。具体地，通过液态合金330可以与衬底导电面直接接触形成欧姆接触，可以达到更好的导电特性和电流稳定性。同样将导线310和衬底110进行固定、并将液态合金330一并固定在导线310和衬底110之间的导电胶，在起到固定包裹作用的同时，也起到了更好的导电特性和电流稳定性。另外，基于上述封装方法，制备了具欧姆接触特性的封装光电极，可以更好的避免衬底导电区域表面与金属导线直接接触形成的肖特基势垒，以利于电流导通。
图4是本公开一实施例中新型日盲紫外光电化学光探测器的制备示意图。作为一可选实施例，光电化学光探测器400还包括：与光阴极结构300接触的电解质溶液(图中未示出)，以及与电解质溶液接触的参比电极420和对电极430，参比电极420和对电极430、光阴极300之间保持一定间 距，并一起被具有至少对日盲紫外光吸收能力有限的透光容器410容纳；其中，参比电极420、对电极430以及光阴极300分别与具备电流监测功能的电化学工作站440相连。电化学工作站440具有光电流监测功能。因此，基本上构成一基于简单的水还原反应作为光电反应机制的光电化学光探测器，其制备条件简单，纯净度要求低，工作过程对电极材料几乎没有影响。
作为一可选实施例，电解质溶液为酸性或中性电解质溶液，酸性电解质溶液包括硫酸、盐酸、高氯酸，中性电解质溶液为硫酸钠，电解质溶液浓度为0.5mol/L；参比电极为银/氯化银电极；对电极包括铂电极、碳电极。通过上述各组成与上述AlGaN纳米线光阴极300一并构成一完整的新型日盲紫外光电化学光探测器。该新型日盲紫外光电化学光探测器，可通过修饰助催化剂进一步优化光探测响应度。
本公开的另一个方面提出了一种新型日盲紫外光电化学光探测器产品，图5是本公开一实施例中新型日盲紫外光电化学光探测器的产品示意图。产品包括上述的光电化学光探测器和用于封装光电化学光探测器的封装结构500，封装结构500包括包覆光电化学光探测器以将其封装的外壳结构510；外壳结构510表面开设有光学窗口511，设置一与光学窗口511相配合的用于密封光学窗口511的透光面520，透光面520与具备AlGaN纳米线120的光阴极表面之间的间距大于等于0.01mm，该间距可以选择0.2cm，但对具体间距不做限制。用于日盲紫外光通过透光面520照射到光阴极300上修饰有助催化剂纳米颗粒的AlGaN纳米线120。该结构形式简单，制备材料易于获取。
作为一可选实施例，透光面520包括对日盲紫外光吸收能力有限的透明材料；外壳结构510包括聚四氟乙烯材料形成的壳体结构。作为一可选实施例，外壳结构510的一个表面上开设有可封闭/开放的注入孔530、排气孔540以及至少3个分别用于设置光阴极、参比电极、对电极的电极孔550、560、570。其制造工艺要求低，成本低廉。
实施例2：
为解决上述传统MSM或者平面薄膜结构光探测器整体光探测性能较 差，同时无法适应于全光谱光探测器大规模生产等问题，本公开提出了一种光电化学光探测器及其制备方法。
本公开提出了一种氮化镓基材料纳米线结构应用于光探测器，并相应提出了该材料结构的制备方法，克服了本领域的技术难题，并且取得了突破性的意料不到的技术效果。其中，本领域技术人员应当理解，该纳米线结构可以是规则性排列，例如定向生长制备的纳米线结构，也可以包括非规则排列的纳米线结构，所谓“规则”可以理解为纳米线的排列具有周期性；所谓“不规则”可以理解为该纳米线的排列不具备周期性，还可以理解为在同一个衬底上，纳米线的长度、直径、相邻纳米线之间的间距、纳米线的生长角度(相对于衬底)等不一致，无规律可循。另外，在本公开中氮化镓基材料的介绍中，例如AlGaN或InGaN仅仅是为本材料的一个符号表达，不代表本材料的标准化学式，相应地，AlGaN的化学式可选Al xGa l-xN，B xAl yGa l-x-yN或In xAl yGa l-x-yN中的一种，0≤x＜1，0≤y≤1。即，该氮化镓基材料可以是AlGaN或InGaN，亦或是AlInGaN等氮化镓基材料，本公开并不对此做任何限制。
在本公开中权利要求书中所提及的光电极，可以是光阴极或光阳极，具体可以以其掺杂组分(例如镁掺杂或硅掺杂)为区分，对应于本公开中还原反应或氧化反应。为清楚地表达本公开中光电极的作用，本公开主要以AlGaN或InGaN纳米线结构的光电极作为示例进行描述。本领域技术人员应当理解，说明书中所提到的AlGaN或InGaN纳米线光阴极，其并非是对光阳极的限定，也并非是对非AlGaN或InGaN光电极的限定。
作为本公开一实施例，生长在衬底表面的AlGaN纳米线，可以通过分子束外延法(Molecular Beam Epitaxy，即MBE)或有机金属化学气相沉积法(Metal Organic Chemical Vapor Deposition，即MOCVD)，常规化学气相沉积法，卤化物气相外延，脉冲激光沉积等方法进行制备，本公开中具体不作限制。同时，为更加清楚地表达本公开的AlGaN纳米线，以下主要以分子束外延法(MBE)为基本制备方法来进行介绍。
本公开的一个方面提出了一种光电化学光探测器的制备方法，如图6本公开一实施例中光电化学光探测器的制备方法流程示意图所示，方法包括：
S610、根据光探测器的待探测光波长选择AlGaN或InGaN组分；在氮化镓基材料中通过控制不同的铝或铟的组分比例，可以获得对应的AlGaN或InGaN材料，不同组分比例的AlGaN或InGaN材料的带隙随Al/Ga，In/Ga，Al/In/Ga组分比例改变而变，对应不同的光吸收波长。在本实施例中，可以控制铝在氮化镓基材料中的组分，也可以控制铟在氮化镓基材料中的组分，以及同时控制铝和铟在氮化镓基材料中的组分，组分比例的修改控制十分简易，同时非常精确。因此，可以更好的适应全光谱光波长对应的纳米线材料的制备，简化了制备工艺。以上仅为本公开实施例中氮化镓基材料中AlGaN或InGaN的介绍，相应地，氮化镓基材料中的铝或铟可替换为硼，其对应的组分调节仍然可以适用上述方案。
S620、根据所述组分在衬底表面上形成AlGaN纳米线或InGaN纳米线；作为本公开一实施例，分子束外延法制备的氮化镓基纳米线结构，因其相较于普通的氧化物和氮化物纳米材料(例如氧化镓纳米结构)，稳定性高，晶体质量高，带隙高度匹配可调等优势，能够保证在光照射下具有优良的水还原/氧化性能，即光探测性能。
S630、在所述AlGaN纳米线或InGaN纳米线上修饰助催化剂纳米颗粒；在AlGaN纳米线或InGaN纳米线上利用助催化剂纳米颗粒修饰法(例如光沉积法)，例如原子层沉积法(Atomic Layer Deposition，ALD)、电沉积法(化学负载方法)、浸渍法(化学负载方法)将助催化剂纳米颗粒修饰在纳米线表面。
S640、对已修饰助催化剂纳米颗粒的AlGaN纳米线或InGaN纳米线进行封装得到光电极，以防止衬底的侧面或背面缝隙漏电，还可以通过银胶及环氧树脂等的固化作用来固定外延片。
S650、以及利用光电极制备光电化学光探测器，光电化学光探测器的组成包括光电极，光电极受到光照射之后产生光生电子-空穴对，从而与光探测器中的其它组成部分形成电流回路，生成的光电流可以被外界检测，以此可以反映光电探测能力，以应用于军事、工业、通信领域。
例如，在分子束外延法的制备过程中，S620中根据所述组分在衬底表面上形成AlGaN纳米线或InGaN纳米线，包括：根据相应的氮化镓基材料组分设置铝(Al)源炉或铟(In)源炉的升温程序及打开或关闭，在衬 底上形成相应组分的氮化镓基纳米线。根据本公开的实施例，采用分子束外延设备，源炉中各单质源在超高真空及一定温度下会产生对应原子束，同时每个炉源的打开/关闭及温度设置可以实现对某个或多个炉源产生的原子束进行精确控制，从而控制不同组分的氮化镓基材料的生成。在本实施例中，若控制铝在氮化镓基材料中的组分，生长AlGaN纳米线，只需要打开铝炉源及镓源炉，关闭铟炉源；若控制铟在氮化镓基材料中的组分，生长InGaN纳米线，只需要打开铟炉源及镓源炉，关闭铝炉源。因此，通过源炉温度调控各个炉源的原子束的体积流量，各个炉源的打开关闭时机，本公开的技术方案可以进一步精确控制纳米线材料组分比例。
作为一可选实施例，根据光探测器的待探测光波长选择AlGaN或InGaN组分，包括：根据下述公式：Eg＝3.42eV+x×2.86eV-x(1-x)1.0eV确定与待探测光波长对应的AlGaN组分；或根据下述公式：Eg＝3.42eV-x×2.65eV-x(1-x)2.4eV确定与待探测光波长对应的InGaN组分。如图7是本公开一实施例中光电化学光探测器的光谱简单对照图，一般光波长小于400nm为紫外光区域，具体地，当光波长小于290nm时，可以达到日盲紫外光区域；可见光光波长一般处于400nm-700nm之间；超过700nm为红外光区域，光电化学光探测器一般研究可见光光波长范围居多。光电化学光探测器光电极半导体材料的能带关系到该材料对相应光波长区间的吸收能力，而光电极半导体材料的能带关系又和氮化镓基纳米材料的合金组分比例相关。因此，只需要通过控制生长纳米线时的铝或铟的组分占比，就可以精确调控其带隙，实现红外、可见光和紫外的全波段光吸收。
作为一可选实施例，根据所述组分在衬底表面上形成AlGaN纳米线或InGaN纳米线，还包括：在衬底上形成纳米孔阵列结构，纳米孔阵列结构的厚度小于等于50nm；在纳米孔中定位填充p型掺杂或n型掺杂的氮化镓基材料形成复合层，将复合层的纳米孔阵列结构去除以在衬底表面上形成氮化镓基纳米线。
具体地，在本公开实施例中，可以利用纳米线/纳米孔的反向形成原理，在衬底的表面制备二氧化硅纳米孔结构，例如厚度最高50nm的二氧化硅纳米孔阵列层，纳米孔可以直接以衬底表面为底面、贯穿二氧化硅层形成。可以在二氧化硅纳米孔结构的纳米孔中预形成氮化镓基晶核，然后通过分 子束外延法或MOCVD法，对纳米孔进行填充，形成AlGaN纳米材料或InGaN纳米材料填充于纳米孔中；另外，即便纳米孔中未形成氮化镓基晶核，由于二氧化硅的惰性特质，当采用衬底为硅衬底或蓝宝石衬底时，例如通过分子束外延或MOCVD法也可以直接在纳米孔底面上形成氮化镓基材料。二氧化硅可以通过化学腐蚀或光学刻蚀等方式予以去除，也可以作为隔离层予以保留，保留的情况下，可能会影响助催化剂纳米颗粒的修饰，因此可选去除二氧化硅，此时便对应形成纳米孔尺寸的AlGaN纳米材料或InGaN纳米线，长度可以是200nm。通过上述方法，对于形成对应波长的高质量单晶氮化镓基纳米线更加快捷、简便，还能够实现相邻纳米线的形体相似度更好。其中，需要说明的是，二氧化硅层的去除与否并非该实施例的关键，其带来的限域作用限制了薄膜的生长，使得本公开可以实现控制在划定区域内生长纳米线。换言之，即便是该二氧化硅纳米孔阵列层的厚度仅有10～50nm，在其上进行纳米孔结构的填充之后，形成的AlGaN纳米材料或InGaN纳米线长度仍然可以生长为200nm。
作为本公开另一实施例，根据所述组分在衬底表面上形成AlGaN纳米线或InGaN纳米线，还包括：在衬底上形成纳米孔阵列结构，纳米孔阵列结构的厚度小于等于50nm；在纳米孔中定位填充氮化镓基材料形成复合层，以及在复合层的表面上、对应于纳米孔的位置继续形成氮化镓基纳米线。此时，复合层并不予以去除，一方面复合层的厚度非常小，例如可以选用20nm的复合层；另一方面，通过选择性区域生长方法可以直接沿纳米孔所在位置相对该纳米孔复合层的其它部分直接形成纳米线，该纳米线实际上会突出于复合层表面，可以达到几百纳米甚至微米级的尺寸，因此纳米线的尺寸会远远大于复合层的尺寸，不去除复合层的情况下，也不会对纳米线的功能造成影响。
作为一可选实施例，根据所述组分在衬底表面上形成AlGaN纳米线或InGaN纳米线，还包括：在所述衬底上形成AlGaN薄膜或InGaN薄膜，对所述AlGaN薄膜或InGaN薄膜进行刻蚀以在所述衬底表面上形成所述AlGaN纳米线或InGaN纳米线。具体地，在本公开实施例中，可选通过分子束外延法或MOCVD法在衬底上直接形成高晶体质量的AlGaN薄膜或InGaN薄膜，之后通过微纳加工技术在AlGaN薄膜或InGaN薄膜上形 成光刻胶、二氧化硅或金属小岛，随后可以通过例如电感耦合等离子体刻蚀法(Inductively Coupled Plasma，ICP)等干法刻蚀方式对AlGaN薄膜或InGaN薄膜进行定位刻蚀，由于二氧化硅或金属刻蚀速度较慢，其余未被保护部分刻蚀较快，以在衬底上形成AlGaN纳米线或InGaN纳米线。其中，相应衬底可以为硅片或蓝宝石衬底。通过上述方法，对于形成对应波长的高质量单晶氮化镓基纳米线更加直接、简便，还能够实现相邻纳米线的形体相似度更好，纳米线形状更加稳定，形状规整可控。
作为一可选实施例，根据上述组分在衬底表面上形成AlGaN纳米线或InGaN纳米线，包括：控制镁或硅的掺杂比例，在衬底上形成相应掺杂比例的p型掺杂或n型掺杂的AlGaN纳米线或InGaN纳米线。具体地，作为本公开一实施例，在分子束外延法制备过程中，通过控制硅(Si)源炉和/或镁(Mg)源炉的开关及源炉温度，可以精确控制纳米线材料的掺杂浓度。
作为一可选实施例，在分子束外延法制备过程中，根据所述组分在衬底表面上形成AlGaN纳米线或InGaN纳米线，包括：将衬底设置于准备腔，在第一温度下对准备腔脱气至少满足第一时间，将准备腔内设置的衬底传送至缓冲腔，在第二温度下对缓冲腔脱气至少满足第二时间，将缓冲腔内的衬底传送至生长腔进行AlGaN纳米线或InGaN纳米线的生长。具体地，在本实施例中，以形成AlGaN纳米线为例，可以使用分子束外延(MBE)设备，以p型Si(100)衬底(即硅片)作为衬底，将硅片传入MBE设备准备腔(例如load lock腔)用于脱气准备，使得MBE设备达到相应的真空度，例如真空度可以达到10 -9，并且在第一温度200℃下保持烘烤脱气时间至少满足第一时间1小时，之后，将准备腔内的硅片送至缓冲腔，在第二温度600℃下保持烘烤脱气时间至少满足第二时间2小时，以尽可能去除缓冲腔内的水及气体分子对硅片的吸附。待脱气完成后，将硅片传送至生长腔，以进行AlGaN纳米线的生长。
作为一可选实施例，在分子束外延法制备过程中，通过控制铝(Al)源炉或铟(In)源炉的打开或关闭，源炉升温程序的控制并根据相应的AlGaN或InGaN组分，在衬底上形成相应组分的AlGaN纳米线或InGaN纳米线，包括：在衬底传送至生长腔后，控制打开与生长腔相连通的镓(Ga) 源炉，以第一等效压强的镓束流作为镓源和第一体积流量的等离子体氮作为氮源，在第三温度下保持至少第三时间，以在衬底表面形成GaN晶种。具体地，在本实施例中，可以使用分子束外延(MBE)设备，以p型Si(100)衬底(即硅片)作为衬底，在硅片进入生长腔之后，控制打开与生长腔相连通的镓源炉，以第一等效压强(BEP)6.0×10 -8Torr镓束流作为镓源和第一体积流量1sccm等离子体氮形成高亮度氮等离子体作为氮源，在第三温度500℃下保持至少第三时间1分钟，以在硅片表面形成GaN晶种，增加成核的可能，给纳米线在硅片的生长形成基点，从而能够在硅片上生长更高晶体质量的纳米线。
作为一可选实施例，在分子束外延法制备过程中，通过控制铝(Al)源炉或铟(In)源炉的打开或关闭，源炉升温程序的控制并根据相应的AlGaN或InGaN组分，在衬底上形成相应组分的AlGaN纳米线或InGaN纳米线，还包括：控制打开铝源炉或铟源炉，在第一体积流量的等离子体氮作为氮源的条件下，在第四温度下保持第二等效压强的铝束流或第三等效压强的铟束流，配合第四等效压强的镓束流，在衬底表面形成相应组分的AlGaN纳米线或InGaN纳米线。具体地，在本实施例中，以形成AlGaN纳米线为例，控制打开铝源炉，在第一体积流量1sccm的等离子体氮作为氮源的条件下，在第四温度610℃下保持第二等效压强2.0×10 -8Torr的铝束流，配合第四等效压强3.0×10 -8Torr的镓束流，在硅片表面形成相应组分的AlGaN纳米线。若是形成InGaN纳米线，由于铝和铟之间的差别，需要打开铟炉源并保持铝炉源关闭，采用第三等效压强4.0×10 -8Torr的铟束流替换相应的铝束流参数，其他步骤可以不作修改。因此，可以通过上述方法，精确地控制纳米线中铝、铟之间的合金占比，从而达到相应的光波长的AlGaN纳米线或InGaN纳米线。通过比较铝或铟，镓束流的BEP来估算铝或铟的成分比例，并通过控制温度调整其BEP比例，达到调控组分的目的，例如，紫外光对应的AlGaN纳米线的制备过程中，通过调节铝的等效压强(BEP)在6×10 -8Torr至1×10 -8Torr之间实现调控Al组分的调控目的；或者，与可见光及红外光对应的InGaN纳米线的制备过程中，通过调节铟的BEP在4×10 -8Torr至1×10 -8Torr之间实现调控In组分的目的。
作为一可选实施例，在分子束外延法制备过程中，通过控制铝(Al)源炉或铟(In)源炉的打开或关闭，源炉升温程序的控制并根据相应的AlGaN或InGaN组分，在衬底上形成相应组分的AlGaN纳米线或InGaN纳米线，还包括：在控制铝(Al)源炉或铟(In)源炉的打开或关闭时，在镁源炉温度为第五温度下或在硅源炉为第六温度下控制镁源炉或硅源炉打开或关闭，以使得在衬底上形成相应组分的AlGaN纳米线或InGaN纳米线成为p型掺杂或n型掺杂。光电极分为光阳极或者光阴极，对应地，p型掺杂的AlGaN纳米线或InGaN纳米线可以更好的完成水还原反应，尤其当其表面修饰助催化剂纳米颗粒时，可以用作光电化学体系的光阴极。一般可以通过掺杂一定比例的镁，使得掺杂后的AlGaN纳米线或InGaN纳米线成为p型掺杂材料，该种掺杂方式可以获得更好的材料稳定性，而且不会对待掺杂材料造成任何影响，后期水还原反应响应更好。相反，n型掺杂的AlGaN纳米线或InGaN纳米线可以更好的完成水氧化反应，尤其当其表面修饰助催化剂纳米颗粒时，可以用作光电化学体系的光阳极。一般可以通过掺杂一定比例的硅，使得掺杂后的AlGaN纳米线或InGaN纳米线成为n型掺杂材料，该种掺杂方式可以获得更好的水氧化反应响应。具体地，在本实施例中，以制备p型AlGaN纳米线为例，在控制铝(Al)源炉打开，同时保证铟(In)源炉关闭时，打开镁源炉，在镁源炉温度为第五温度360℃下，以使得在衬底上形成相应组分的AlGaN纳米线成为p型掺杂。相反，若以制备n型InGaN纳米线为例，需要打开硅源炉，硅源炉的反应第六温度为1180℃。
作为一可选实施例，在所述AlGaN纳米线或InGaN纳米线上修饰助催化剂纳米颗粒，包括：将AlGaN纳米线或InGaN纳米线设置在第一浓度的前驱体水溶液中，同时施加与纳米线能带相应波长的光线照射，以在AlGaN纳米线或InGaN纳米线表面修饰助催化剂纳米颗粒。具体地，在本实施例中，以制备p型AlGaN纳米线上修饰助催化剂Pt纳米颗粒为例，可以选用一定浓度的氯铂酸溶液作为前驱体水溶液，将所生长的p型Al xGa l-xN纳米线置于50mL去离子水中，在密封容器中，通过循环水冷方法保持反应温度维持在10℃，保持一定真空度，同时向容器通入惰性气体例如氩气作为保护气体，将1ml浓度为10mg/ml的氯铂酸溶液注入容器， 施加与Al xGa l-xN纳米线带隙对应波长的光照，保持光照时间超过30分钟。由半导体光电效应，Al xGa l-xN纳米线吸收光子后产生光生电子-空穴对。随后光生电子扩散至纳米线表面，因光生电子能量大于溶液中的铂酸根([PtCl 6] 2-)基团的还原电位，扩散至纳米线表面的光生电子将还原吸附于纳米线表面的[PtCl 6] 2-，在纳米线表面形成铂颗粒，即光沉积过程。光沉积反应完成之后，取出样品并清洗，即可得到修饰助催化剂铂纳米颗粒的p型AlGaN纳米线，其中铂颗粒粒径尺寸可以达到0.1nm-1000nm。对于n型纳米线而言，只需要将前驱体水溶液氯铂酸溶液换成可以等浓度的氯化钌溶液即可。通过在纳米线表面分布修饰助催化剂纳米颗粒，可以使得光电极在水还原/氧化反应的过程中，反应更加强烈，反应速度更快，光电流更大。
作为一可选实施例，在所述AlGaN纳米线或InGaN纳米线上修饰助催化剂纳米颗粒之前，还包括：当AlGaN纳米线或InGaN纳米线为n型掺杂时，在AlGaN纳米线或InGaN纳米线表面制备保护层。由于n型掺杂在分子束外延法制备工艺中较易实现，但是在光沉积或光探测过程中，其生长的纳米线易于被自身产生的光生空穴腐蚀，因而对光阳极造成一定的影响，因此，需要在光阳极的纳米线基础上，在纳米线表面制备一层具有隧道导通效应、同时满足导电性良好不会对光探测性能造成影响的纳米线保护层。具体地，在本实施例中，以制备n型InGaN纳米线为例，在对其进行光沉积以修饰助催化剂纳米颗粒之前，利用原子层沉积法直接在n型InGaN纳米线表面沉积一层无定型的保护层，保护层的材料可以是TiO 2或类似性能的材料，以防止n型InGaN纳米线材料在空穴富集情况下发生光腐蚀。以无定型TiO 2保护层为例，制备过程中可以采用四(二甲基胺基)钛(IV)TEMAT及水为前驱，前驱容器分别保持在65℃及25℃.共沉积60个周期。每个周期包含过程为钛前驱通入0.1秒，等离子体氮通入10秒，水蒸气通入0.1秒，N 2通入10秒，最后可以在n型InGaN纳米线材料表面形成无定型的TiO 2保护层。
作为一可选实施例，对已修饰助催化剂纳米颗粒的AlGaN纳米线或InGaN纳米线进行封装得到光电极，包括：将导线固定贴附在具备已修饰助催化剂纳米颗粒的AlGaN纳米线或InGaN纳米线的衬底的导电区域上， 将导线连同衬底包覆固定、同时露出AlGaN纳米线或InGaN纳米线以形成封装光电极。封装光电极，需要注意将导线引出，另外还需要注意将光电极的纳米线暴露在外。将导线引出时，需注意导线的一端需要与硅片的预定导电区域相对，导电区域可以是硅片的背面或者正面利用金刚石笔刮除纳米线之外的某个区域。露出的光阴极纳米线，以利于相应光波长的光可以直接照射到纳米线。
作为一可选实施例，将导线固定贴附在具备已修饰助催化剂纳米颗粒的AlGaN纳米线或InGaN纳米线的衬底的导电区域上，包括：在衬底导电区域上刮除氧化层，在刮除了氧化层的导电区域上涂覆液态合金，在导线和导电区域之间、与液态合金位置相对的导线表面上涂覆导电胶。为防止所用衬底与金属导线直接接触会形成肖特基势垒不利于电流导通，需制备具欧姆接触特性的光电极。具体地，在本公开实施例中，以硅片作为衬底为例，先用金刚石刀刮去硅片背面自然生长的二氧化硅(SiO 2)层，向刮除二氧化硅层之后的硅片背面的导电区域，涂覆液态合金(例如镓铟(GaIn)合金)，形成欧姆接触。随后于导线铜(Cu)条上涂覆抹导电胶银(Ag)胶，并将其与涂有镓铟合金的硅片背面压实，最后用环氧树脂封装包裹整个光电极，仅留纳米线生长面暴露，从而完成对光电极的初步封装，避免了肖特基势垒的形成，有利于光电流的导通。
作为一可选实施例，利用光电极制备光电化学光探测器，包括：将光电极以及参比电极、对电极以一定间距设置于第二浓度的电解质溶液中制备为三电极体系，构成光电化学光探测器。具体地，在本公开实施例中，以制备p型AlGaN纳米线的光阴极三电极体系为例，透光容器中加入电解质溶液溶液(以第二浓度为0.5mol/L硫酸(H 2SO 4)水溶液为例)，随后分别将上述所制Al xGa l-xN纳米线电极(光阴极)，参比电极(以银/氯化银(Ag/AgCl)为例)，对电极(以铂Pt网电极为例)置于电解质溶液溶液中，三电极体系即制备完成，本公开的光电化学光探测器基本形成。在各电极的导电端连接电化学工作站，通过电脑设置电化学工作站测试参数，即可以进行光探测性能的测试或应用。相应地，以n型InGaN纳米线的光阳极为例，可以将电解质溶液溶液替换为1mol/L的氢溴酸溶液即可。该三电极体系的制备过程简单易行，极大地简化了光探测器的制备工艺，使得其 具备大规模生产的条件。
本公开的另一方面提出了一种光电化学光探测器，应用上述的光电化学光探测器制备方法制备，光探测器包括一具备氮化镓基纳米线的光电极。
本公开提出的一种新型光电化学光探测器制备方法，其基于氮化镓(GaN)基材料，通过调控铝或铟相对于镓的合金比例，针对性的调控材料带隙，形成一可以同时制备紫外-可见-红外探测波长的全光谱、带隙可调新型光电化学光探测器的通用制备方法。即，根据实际所需探测的波长氮化镓基化合物半导体材料生长阶段选择合适的铝：镓或铟：镓比例，精确调控所制备的氮化镓基纳米线带隙，得到对应波长的高质量单晶氮化镓基纳米线。因材料体系相同，助催化剂纳米颗粒修饰、光电极封装、光电化学体系制备流程完全一致，无需因探测波长需求改变变更材料体系或调整工艺，大大降低了制造成本，适用性高。仅在纳米线生长过程中调整参数即可生产出应用于不同光探测场景的光探测器。最后采取相同工艺流程制备高响应度、快速反应、经济环保、自供能的新型全波段光电化学光探测器，替代了性能较差的传统MSM光探测器。本公开开创性的将氮化镓基纳米线应用于光电化学光探测器的研究中，具有十分重要的意义。
本公开的另一方面提出了一种新型光电化学光探测器，应用上述的新型光电化学光探测器制备方法制备，光探测器包括一具备氮化镓基纳米线的光电极。
本公开提出的一种新型光电化学光探测器，在衬底上定向生长p型掺杂或n型掺杂氮化镓基纳米线，其具有较大的比表面积，与电解质溶液形成的界面接触多，有利于光生载流子的分离和运输。另外，在氮化镓基纳米线上修饰助催化剂纳米颗粒(例如铂Pt或钌Ru)作为光电极，优化了反应物/生成物的吸脱附过程，提高了光电极在溶液中的水还原/氧化反应速率，确保了光电转换效率，获得更大光电响应电流，更高的光响应度，响应时间可根据实际需求精确调控。同时，进一步优化光电化学装置设计，改变电解质溶液环境，最终实现高响应度、灵敏度高、快速反应、经济环保、自供能(无需外加额外电能)的全光谱新型光电化学光探测器，替代了性能较差的传统MSM光探测器，弥补了光电化学光探测器采用氮化镓基材料制备的空白。本公开开创性的将氮化镓基纳米线应用于光电化学光 探测器的研究中，具有十分重要的意义。
实施例3：
本公开的一个方面提出了一种日盲紫外光电化学光探测器，如图8A是本公开一实施例中日盲紫外光电化学光探测器GaN基纳米孔阵列的示意图，以及图8B是本公开一实施例中日盲紫外光电化学光探测器已修饰助催化剂纳米颗粒的GaN基纳米孔阵列的示意图所示，所述光探测器包括光电极，光电极包括衬底810，还包括在衬底810表面上形成的GaN基纳米孔840阵列830，从而构成本公开所提出的新型光电化学光探测器光阴极的基本结构800。
其中，本领域技术人员应当理解，该纳米孔结构可以是规则性排列，例如定向生长制备的纳米孔结构，也可以包括非规则的无序纳米孔结构，所谓“规则”可以理解为纳米孔的排列是否具有周期性。1另外，该氮化镓基材料在本公开中可选为AlGaN，AlGaN仅仅是为本材料的一个符号表达，不代表本材料的标准化学式。具体地，GaN基的化学式可选B xAl yGa l-x-yN或In xAl yGa l-x-yN中的一种，0≤x＜1，0≤y≤1。即，该氮化镓基材料可以是AlGaN或InGaN，亦或是AlInGaN等氮化镓基材料，本公开并不对此做任何限制。
在本公开中权利要求书中所提及的光电极，可以是光阴极或光阳极，具体可以以其掺杂组分(例如镁掺杂或硅掺杂)为区分，对应于本公开中还原反应或氧化反应。为清楚地表达本公开中光电极的作用，本公开主要以AlGaN光阴极作为示例进行描述。本领域技术人员应当理解，其并非是对光阳极的限定，也并非是对非AlGaN光电极的限定。
作为本公开一实施例，生长在衬底上的AlGaN纳米孔阵列，可以通过分子束外延法(Molecular Beam Epitaxy，即MBE)或有机金属化学气相沉积法(Metal Organic Chemical Vapor Deposition，即MOCVD)常规化学气相沉积法，卤化物气相外延，脉冲激光沉积等方法进行制备，本公开中具体不作限制。同时，为更加清楚地表达本公开的AlGaN纳米孔阵列，以下主要以有机金属化学气相沉积法(MOCVD)作为基本制备方法来进行介绍。
在衬底表面上定向形成高晶体质量n型掺杂AlGaN纳米孔阵列，因其相较于普通的氧化物和氮化物纳米材料(例如氧化镓纳米结构)，稳定性高，晶体质量高，带隙高度匹配可调等优势，能够保证在日盲光照射下具有优良的水氧化性能，即光探测性能。另外，对于AlGaN材料，其带隙可以随组分掺杂改变，具体而言：
Eg＝3.42eV+x*2.86eV-x(1-x)*1.0eV………………………(1)
Eg为半导体禁带宽度，对应不同的吸收波长。
因此，根据公式(1)，通过控制制备工艺中Al、Ga组分占比，即可精确调控制备成的光阳极带隙，实现日盲紫外波段的光吸收。
另外，本公开制备的高晶体质量的AlGaN纳米孔可以为p型掺杂材料，具体而言，可以掺入硅Si原子，在后续光电化学反应过程中移动到电解质溶液/半导体接触面为电子，不会对AlGaN纳米材料或结构造成任何影响，相对于尚未能实现氧化物纳米材料(例如氧化镓纳米结构)，稳定性非常高。相应地，本公开的所制备的AlGaN纳米孔可以为p型掺杂材料，具体而言，可以掺入镁Mg原子，以备将其作为光阴极使用。需要说明的是，在光阳极的结构中，需在其表面沉积一定厚度的保护层，防止其在光探测过程中被光生空穴腐蚀。
如图8A所示，作为本公开一实施例，AlGaN纳米孔840可以为圆柱形孔或棱柱形等规则孔，也可以为曲状形等不规则孔，可选纳米孔840为圆柱形孔。该纳米孔840直径为0.1μm-5μm，可选直径为2μm；其深度为50nm-600nm，可选深度为200nm。使得该纳米孔840阵列的比表面积更大，同时增加光探测反应的比表面积。另外，其纳米孔840孔径大小超过500nm，远远超过常规纳米孔的设计尺寸，一定意义上而言已不算是纳米级结构。此种尺寸设计，可以防止后续光探测过程中产生的气泡附着在纳米孔840内表面引起溶液传质困难，而大孔径纳米孔设计由于极易造成短路等性能不稳定的情况，且在本领域中就没有如此大孔径纳米孔设计研究，因此会阻碍本领域技术人员去实施这一方案。因此，这是本领域中突破性的设计方案，是本领域技术人员无法想到的。
作为本公开一实施例，AlGaN纳米孔阵列填充度可由图形化条件定义，相邻纳米孔之间的间距为0.1μm-5μm，可选间距为2μm。使得该纳米 孔阵列的比表面积更大，同时增加光探测反应的比表面积。
如图8A-图8B所示，作为本公开一实施例，衬底810包括蓝宝石衬底、氮化镓衬底、氧化镓衬底、碳化硅衬底、硅衬底或具备GaN基材料薄膜的衬底等或其他具备导电性能的衬底。可选衬底为蓝宝石衬底，在本公开实施例中该衬底材料可选为氧化铝Al 2O 3等。
作为本公开一实施例，GaN基纳米孔阵列为n型GaN基纳米孔阵列，光电极的GaN基纳米孔阵列表面还包括覆盖于纳米孔阵列表面的保护层，保护层厚度小于等于10nm，保护层材料至少包括二氧化钛。保护层用于防止纳米孔的光腐蚀现象。相应地，对于本公开中对应的p型氮化镓基纳米孔(例如AlGaN或InGaN纳米孔等，在此不作限制，依照权利要求书所限定的保护范围为准)，可以作为本公开中光电化学光探测器的光阴极(对应于前述实施例中的氮化镓基纳米线光阴极)，对应地，可选在该p型纳米孔表面上直接修饰助催化剂纳米颗粒，不必在修饰助催化剂纳米颗粒之前在该纳米孔表面形成至少一保护层，此处不再赘述。
由于晶格匹配，可在该衬底810上外延形成稳定高晶体质量的AlGaN单晶薄膜，有利于下一步纳米孔阵列的制备。
如图8A-图8B所示，作为本公开一实施例，衬底810和AlGaN纳米孔阵列830之间还包括缓冲层820，缓冲层820包括至少三层中间层，缓冲层材料包括氮化铝。由于衬底810和AlGaN纳米孔阵列830的晶格不匹配，所以，在二者之间增加缓冲层820，有利于在制备过程中得到稳定、高晶体质量的AlGaN单晶薄膜，有利于下一步纳米孔阵列的制备。
作为本公开一实施例，缓冲层820包括至少三层中间层，形成于衬底810上的第一中间层，厚度可以是3μm，用于作为成核层；形成于第一中间层上的第二中间层，厚度可以是100nm；形成于第二中间层上的第三中间层，厚度可以是1μm，用于作为模板层。上述多个中间层未在附图示出。多层中间层的构成，有利于形成更加平整光滑的第三中间层表面(即缓冲层820表面)，使得在制备过程中得到稳定、高晶体质量的AlGaN单晶薄膜，有利于下一步纳米孔阵列的制备。相应地，对于本公开中对应的p型氮化镓基纳米孔(例如AlGaN或InGaN纳米孔等，在此不作限制，依照权利要求书所限定的保护范围为准)，可以作为本公开中光电化学光 探测器的光阴极(对应于前述实施例中的氮化镓基纳米线光阴极)，对应地，可选在衬底表面上直接形成该氮化镓基纳米孔结构，而不必考虑在纳米孔结构和衬底之间增加上述缓冲层结构。
图8B所示，作为本公开一实施例，AlGaN纳米孔阵列表面还覆盖一层保护层870，保护层870厚度小于等于10nm，可选厚度尺寸为2nm。在本公开实施例中，保护层可选为无定型二氧化钛TiO 2保护层，覆盖在整个AlGaN纳米孔阵列表面，包括纳米孔的内表面，以防止在光探测过程中，AlGaN材料在空穴富集条件下发生光腐蚀效应，影响光探测器的整体性能。
如图8B所示，作为本公开一实施例，光阳极还包括分布于保护层表面的助催化剂纳米颗粒850，助催化剂纳米颗粒850为水氧化还原反应活性的金属颗粒，金属颗粒的材料包括铂、铱、铁、钴、镍或钌等及其多元合金，合金即为同时使用两种金属，比如RuFe，RuCo等。本公开可选钌作为助催化剂纳米颗粒的制备选择，助催化剂纳米颗粒的直径尺寸可选0.1nm-1000nm，可选为2nm以更好更多的修饰在纳米孔阵列中。分布于纳米孔阵列上的助催化剂纳米颗粒可以使得AlGaN纳米孔阵列具备更强的水氧化反应，使得光探测器的光响应更加强烈，光响应速度更快。
如图8B所示，作为本公开一实施例，AlGaN纳米孔阵列表面还包括一未覆盖保护层870的第一区域860，第一区域860设置于纳米孔区域之外。第一区域形成在纳米孔阵列表面，与纳米孔所在区域不相重叠，以防止短路的情况发生，另外还可以使得引出电极更加稳定有效。
作为本公开一实施例，第一区域860上包括有点焊铟球，用于形成光阳极的导电区域，用于引出光阳极。通过点焊铟球可以在第一区域860上与纳米孔阵列表面形成欧姆接触的导电区域，导电区域可选2mm×2mm的方形区域，可以达到更好的导电特性和电流稳定性，同时可以固定导线引出电极，即可以形成光阳极。
作为本公开一实施例，与光阴极构成的光电化学光探测器的结构类似，光电化学光探测器还包括：与光阳极接触的电解质溶液，以及与电解质溶液接触的参比电极和对电极，参比电极和对电极、光阳极之间保持一定间距，其中，该间距大约等于0.01mm；其中，参比电极、对电极以及光阳极分别与具备电流监测功能的电化学工作站相连。因此，基本上构成一基 于简单的水氧化反应作为光电反应机制的光电化学光探测器，其制备条件简单，纯净度要求低，工作过程对电极材料几乎没有影响。
作为本公开一实施例，电解质溶液包括酸性或中性电解质溶液，中性电解质溶液为硫酸钠，酸性电解质溶液包括磷酸缓冲液或氢溴酸，电解质溶液浓度为0.01mol/L～5mol/L，本公开可选0.5mol/L氢溴酸溶液等弱酸性电解质溶液；参比电极为银/氯化银(Ag/AgCl)电极等；对电极包括铂(Pt)电极、碳(C)电极等，具体结构可以做成网状电极等形式。通过上述各组成与上述AlGaN纳米孔阵列光阳极一并构成一完整的新型日盲紫外光电化学光探测器。该新型日盲紫外光电化学光探测器，可通过修饰助催化剂纳米颗粒进一步优化光探测响应度。
本公开的另一个方面提出了一种日盲紫外光电化学光探测器产品，与光阴极光探测器的产品结构类似，产品包括上述的光探测器和用于封装光探测器的封装结构，封装结构包括包覆光探测器以将其封装的外壳结构；外壳结构一表面开设有光学窗口，设置一与光学窗口相配合的用于密封光学窗口的透光面，透光面与具备AlGaN纳米孔阵列的光阴极表面以一定间距设置，其中，该间距大约等于0.01mm，本实施例中该间距可以选择0.2cm，用于日盲紫外光通过透光面照射到光阳极上分布有助催化剂纳米颗粒的AlGaN纳米孔阵列。该结构形式简单，制备材料易于获取。
作为本公开一实施例，透光面包括对日盲紫外光吸收能力有限的透明材料；外壳结构包括聚四氟乙烯材料形成的壳体结构。作为一可选实施例，外壳结构的一个表面上开设有可封闭/开放的注入孔、排气孔以及至少3个分别用于设置光阴极、参比电极、对电极的电极孔。其制造工艺要求低，成本低廉。
本公开提出的一种新型日盲紫外光电化学光探测器产品，由于上述的光电化学光探测器的结构简单、制造工艺要求低，成本低廉，且该产品的封装结构非常简易，方便于实际应用且易于大规模生产，实现了光电化学光探测器的产品化。
本公开的另一个方面提出了一种日盲紫外光电化学光探测器的制备方法，应用于制备上述的光探测器，如图9本公开一实施例中日盲紫外光电化学光探测器制备方法流程示意图所示，该制备方法包括：
S910、在衬底表面上形成AlGaN纳米孔阵列；具体地，作为本公开一实施例，可选金属有机化学气相沉积法(MOCVD)对其进行制备，在该制备过程中可选三乙基硼烷(TEB)、三甲基铝(TMAl)、三甲基镓(TMGa)、氨气(NH 3)作为生长前驱物以提供B、Al、Ga、N源，Si作为n型掺杂源，H 2作为载气。在氮化镓基材料中通过控制不同的铝、镓的组分比例，可以获得对应的AlGaN材料，不同组分比例的AlGaN材料可以使得材料本身的能带对应不同，带隙随掺杂组分改变，以对应不同的光吸收波长。在本实施例中，可以控制铝在氮化镓基材料中的组分，组分比例的修改控制十分简易，同时非常精确。因此，可以更好的适应宽光谱光波长对应的纳米材料的制备，也可以精确控制形成适应日盲紫外光波长的纳米材料，简化了制备工艺。同时利用硅对形成的AlGaN纳米孔阵列进行掺杂，可以得到更加适合光阳极的n型掺杂AlGaN纳米孔阵列，有利于提升光探测器的水氧化反应，提高光电流响应强度和速度。
S920、在AlGaN纳米孔阵列的纳米孔上修饰助催化剂纳米颗粒；具体地，作为本公开一实施例，在AlGaN纳米孔阵列的纳米孔上利用光沉积法，或原子层沉积法(Atomic Layer Deposition，ALD)、电沉积法(化学负载方法)、浸渍法(化学负载方法)将助催化剂纳米颗粒修饰在纳米孔结构的表面/侧面。
S930、利用已修饰助催化剂纳米颗粒的AlGaN纳米孔阵列作为光阳极制备光探测器。
在衬底表面上制备光阳极功能层，以更低地成本确保了更高晶体质量的AlGaN纳米孔阵列；在衬底和AlGaN纳米孔阵列之间形成缓冲层，提高了AlGaN薄膜的成膜效果，同时保证了高晶体质量AlGaN纳米孔阵列的形成；AlGaN纳米孔阵列表面覆盖一层无定型保护层，可以防止光阳极在光探测过程中发生光腐蚀效应，影响光探测器的整体光探测性能；另外，在保护层表面修饰助催化剂纳米颗粒进一步提高了水氧化反应速率，从而提高紫外光响应。
如图10A本公开一实施例中日盲紫外光电化学光探测器制备方法中AlGaN纳米孔阵列制备流程一阶段示意图所示，作为本公开一实施例，在衬底表面上形成AlGaN纳米孔阵列，包括：对衬底810进行预退火；在 经过预退火的衬底810上形成缓冲层820；根据本公开的实施例，生长前，预先在H 2-NH 3环境中对蓝宝石衬底进行1200℃、5分钟的高温退火，使得蓝宝石衬底表面更加清洁平整，更加适合作为AlGaN纳米孔阵列的衬底。在衬底810的缓冲层820表面可选通过金属有机化学气相沉积法MOCVD法或分子束外延法(MBE)形成AlGaN纳米孔阵列，具体方法不作限制。在形成AlGaN纳米孔阵列之前，在缓冲层820表面预形成一层AlGaN薄膜831，根据本公开的实施例，在温度为1150℃下在缓冲层上生长200nm的AlGaN薄膜。通过对薄膜831的进行操作，以形成纳米孔阵列。通过先形成薄膜831，可以保证形成纳米孔阵列的高晶体质量。
作为本公开一实施例，在经过预退火的衬底810上形成缓冲层820，包括：在缓冲层820至少包括两层中间层(未示出)；在衬底810上以第一条件形成第一中间层，在第一中间层上以第二条件形成第二中间层；在第二中间层上以第三条件形成第三中间层。具体地，在经过预退火的蓝宝石沉底810上形成缓冲层820，可选以MOCVD作为制备手段，包括：以AlN作为缓冲层制备材料，首先在850℃-950℃温度下、TMAl和NH 3的体积流量分别控制在4sccm和3000sccm的第一条件下在蓝宝石衬底810上形成3μm厚度尺寸的低温AlN成核层，作为第一中间层；在850-1250℃温度下的第二条件下，在第一中间层上形成厚度尺寸可达100nm的AlN间隔层，作为第二中间层；在1250℃、V/III为180的第三条件下在第二中间层上形成1μm厚度尺寸的高温AlN模板层，作为第三中间层。多层中间层的构成，有利于形成更加平整光滑的第三中间层表面(即缓冲层820表面)，使得在制备过程中得到稳定、高晶体质量的AlGaN纳米孔阵列。
作为本公开一实施例，在衬底的缓冲层表面形成AlGaN纳米孔阵列，包括：在缓冲层以第四条件形成AlGaN薄膜；对薄膜进行刻蚀，形成AlGaN纳米孔阵列。如图10A至图10F中本公开各实施例中日盲紫外光电化学光探测器制备方法中AlGaN纳米孔阵列制备流程一阶段示意图所示，利用微纳加工技术手段制备圆柱形纳米孔阵列，其中AlGaN薄膜可以形成在第三中间层上。如图10A至图10B所示，所描述的第四条件包括如下步骤中使用的任一制备条件：使用型号为S1813的光刻胶作为后续刻蚀工艺的刻蚀牺牲层910，涂胶速率控制在4000转/分，时间30秒，形成厚度约 1.2μm的光刻胶牺牲层910；如图10C所示，在掩膜版320上绘制直径2μm的圆形，相邻图形间距为2μm，形成阵列结构，后烘温度控制在115℃，时间90秒；使用Optical Aligner-SUSS MABA6紫外光刻机进行图形定义，采用接触式曝光，间距60μm，曝光时间为7.5秒(step3)；随后在AZ300MIF显影液中显影50秒暴露图形，使得牺牲层910上形成对应纳米孔位置的曝光显影区域定义的圆形图案911，在清水中清洗。如图10D所示，可选使用感应耦合等离子体(ICP)刻蚀AlGaN薄膜首先实现牺牲层910上的纳米孔结构930。如图10E所示，利用Oxford ICP 180刻蚀MOCVD生长的AlGaN薄膜，刻蚀区域为紫外光刻定义的圆形图案911。刻蚀气体为Cl 2/BCl 3/Ar，气体流量控制在10/25/25sccm，温度为50℃，腔体压力6mTorr，ICP功率450W，射频功率100W。刻蚀开始前不放入样品，使用上述工艺参数空腔运行，保证腔体气体环境。刻蚀开始后控制刻蚀时间为2.5分钟，形成深度为200nm的AlGaN纳米孔。AlGaN与S1813光刻胶的选择比为1∶2，刻蚀后S1813光刻胶剩余厚度约800μm(step5)。使用丙酮、异丙醇、水洗掉样品上剩余的光刻胶，完成纳米孔阵列的制备，如图10F所示。
作为本公开一实施例，可以在衬底的缓冲层820表面形成AlGaN纳米孔阵列830，包括：在缓冲层820表面形成二氧化硅小岛，在形成二氧化硅小岛的缓冲层820表面形成所述AlGaN纳米孔阵列830。小岛可以是形成于缓冲层820表面的凸起或区域，利用特殊处理工艺或特殊材料制备形成。具体地，可选在缓冲层820的第三中间层表面，通过微纳加工技术手段，在该第三中间层表面形成二氧化硅小岛，之后，通过分子束外延(MBE)或金属有机化学气相沉积法(MOCVD)在已形成二氧化硅小岛的第三中间层表面直接进行薄膜生长。由于二氧化硅小岛对薄膜生长具有阻碍作用，二氧化硅小岛的所在位置不会形成薄膜材料。最终在缓冲层820表面形成所述AlGaN纳米孔阵列830。作为本公开一实施例，上述小岛的材料可选二氧化硅、二氧化钛、氮化硅或金属等材料，上述对二氧化硅小岛的描述并非是对该小岛材料的限制。
作为本公开一实施例，在AlGaN纳米孔阵列的纳米孔上修饰助催化剂纳米颗粒，包括：在AlGaN纳米孔阵列表面形成一覆盖纳米孔阵列表面的无定型保护层；在保护层表面修饰助催化剂纳米颗粒。如图10G本公 开各实施例中日盲紫外光电化学光探测器制备方法中AlGaN纳米孔阵列制备流程一阶段示意图所示，可选通过原子层沉积法(ALD)沉积2nm厚无定型TiO 2保护层(a-TiO 2)870，防止AlGaN材料在空穴富集条件下发生光腐蚀。沉积过程采用四(二甲基胺基)钛(IV)TEMAT及水为前驱，前驱容器分别保持在65℃及25℃.共沉积60个周期。每个周期包含过程为钛前驱通入0.1s，N 2吹扫10s，水蒸气通入0.1s，N 2吹扫10s，通过原子层沉积法在AlGaN纳米孔阵列表面形成一覆盖纳米孔阵列表面的无定型保护层870，用于保护纳米孔阵列不受空穴腐蚀，其因具有隧道导通效应，导电性良好，不会对探测性能造成影响。
如图10H本公开各实施例中日盲紫外光电化学光探测器制备方法中AlGaN纳米孔阵列制备流程一阶段示意图所示，在保护层870表面可选利用光沉积法修饰助催化剂纳米颗粒850，于向20mL去离子水中加入100μL 20mg/mL氯化钌(RuCl3)溶液，将所制得a-TiO 2/n-AlGaN纳米孔阵列置于其中，同时对a-TiO 2/n-AlGaN纳米孔阵列施加带隙对应的紫外光照。由于半导体光电效应，a-TiO 2/n-AlGaN纳米孔阵列吸收光子后产生光生电子-空穴对。随后光生电子扩散至纳米孔表面，因光生电子能量大于溶液中的钌离子Ru 3+的还原电位，扩散至纳米孔表面的光生电子将还原修饰于a-TiO 2/n-AlGaN纳米孔阵列表面的Ru 3+，形成纳米Ru颗粒，纳米颗粒可选2nm。
作为本公开一实施例，利用已修饰助催化剂纳米颗粒的AlGaN纳米孔阵列作为光阳极制备光探测器，包括：在AlGaN纳米孔阵列表面形成一未覆盖保护层的第一区域，第一区域设置于纳米孔区域之外；在第一区域上设置点焊铟球以形成光阳极的导电区域，用于引出光阳极。第一区域形成在纳米孔阵列表面，与纳米孔所在区域不相重叠，以防止短路的情况发生，另外还可以使得引出电极更加稳定有效。通过点焊铟球可以在第一区域860上与纳米孔阵列表面形成欧姆接触的导电区域，导电区域可选2mm×2mm的方形区域，可以达到更好的导电特性和电流稳定性，同时可以固定导线引出电极，即可以形成光阳极。
作为本公开一实施例，利用已修饰助催化剂纳米颗粒的AlGaN纳米孔阵列作为光阳极制备光探测器，还包括：将参比电极和对电极、光阳极 以一定间距设置于电解质溶液中制备三电极体系，构成光探测器。因此，基本上构成一基于简单的水氧化反应作为光电反应机制的光电化学光探测器，其制备条件简单，纯净度要求低，工作过程对电极材料几乎没有影响。
至此，已经结合附图对本公开实施例进行了详细描述。依据以上描述，本领域技术人员应当对本公开有了清楚的认识。
以上所述的具体实施例，对本公开的目的、技术方案和有益效果进行了进一步详细说明，应理解的是，以上所述仅为本公开的具体实施例而已，并不用于限制本公开，凡在本公开的精神和原则之内，所做的任何修改、等同替换、改进等，均应包含在本公开的保护范围之内。

Claims (11)

  1. 一种光电化学光探测器的制备方法，其中，所述方法包括：
    根据所述光探测器的待探测光波长选择氮化镓基材料组分；
    根据所述组分在衬底表面上形成氮化镓基纳米线；
    在所述氮化镓基纳米线上修饰助催化剂纳米颗粒；
    对已修饰助催化剂纳米颗粒的氮化镓基纳米线进行封装得到光电极；以及
    利用所述光电极制备所述光电化学光探测器。
  2. 根据权利要求1所述的方法，其中，根据所述光探测器的待探测光波长选择氮化镓基材料组分，包括：
    根据下述公式：
    Eg＝3.42eV+x×2.86eV-x(1-x)×1.0eV
    确定与所述待探测光波长对应的Al xGa 1-xN组分；或
    根据下述公式：
    Eg＝3.42eV-x×2.65eV-x(1-x)×2.4eV
    确定与所述待探测光波长对应的In xGa 1-xN组分；
    其中，Eg为半导体禁带宽度，对应不同光波段的吸收波长。
  3. 根据权利要求1所述的方法，其中，根据所述组分在衬底表面上形成氮化镓基纳米线，还包括：
    在所述衬底上形成纳米孔阵列结构，所述纳米孔阵列结构的厚度小于等于50nm；
    在所述纳米孔中定位填充氮化镓基材料形成复合层，以及
    在所述复合层的表面上、对应于所述纳米孔的位置继续形成所述氮化镓基纳米线；或
    将所述复合层的纳米孔阵列结构去除以在所述衬底表面上形成所述氮化镓基纳米线。
  4. 根据权利要求1所述的方法，其中，根据所述组分在衬底表面上形成氮化镓基纳米线，还包括：
    在所述衬底上形成氮化镓基薄膜，
    对所述氮化镓基薄膜进行刻蚀以在所述衬底表面上形成所述氮化镓基纳米线。
  5. 根据权利要求1所述的方法，其中，根据所述组分在衬底表面上形成氮化镓基纳米线，包括：
    控制镁或硅的掺杂比例，在所述衬底上形成相应掺杂比例的p型掺杂或n型掺杂的氮化镓基纳米线。
  6. 根据权利要求1所述的方法，其中，在所述氮化镓基纳米线上修饰助催化剂纳米颗粒，包括：
    将所述氮化镓基纳米线设置在第一浓度的前驱体水溶液中，同时施加与所述纳米线能带相应波长的光线照射，以在所述氮化镓基纳米线表面修饰助催化剂纳米颗粒。
  7. 根据权利要求6所述的方法，其中，在所述氮化镓基纳米线上修饰助催化剂纳米颗粒之前，还包括：
    当所述氮化镓基纳米线为n型掺杂时，在所述氮化镓基表面形成保护层，所述保护层厚度小于等于10nm。
  8. 根据权利要求1所述的方法，其中，对已修饰助催化剂纳米颗粒的氮化镓基纳米线进行封装得到光电极，包括：
    将导线固定贴附在具备已修饰助催化剂纳米颗粒的所述氮化镓基纳米线的衬底的导电区域上，
    将所述导线连同所述衬底包覆固定、同时露出所述氮化镓基纳米线以形成封装光电极。
  9. 根据权利要求8所述的方法，其中，所述将导线固定贴附在具备已修饰助催化剂纳米颗粒的所述氮化镓基纳米线的衬底的导电区域上，包括：
    在所述衬底所述导电区域上刮除氧化层，在所述刮除了氧化层的导电区域上涂覆液态合金，
    在所述导线和所述导电区域之间、与所述液态合金位置相对的导线表面上涂覆导电胶。
  10. 根据权利要求1所述的方法，其中，所述利用所述光电极制备所述光电化学光探测器，包括：
    将所述光电极以及参比电极、对电极以一定间距设置于第二浓度的电解质溶液中制备为三电极体系，构成所述光电化学光探测器，所述间距大于等于0.01mm。
  11. 一种光电化学光探测器，采用权利要求1-11中任一项所述的方法制备而成，其中，所述光探测器包括一具备氮化镓基纳米线的光电极。
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113488433A (zh) * 2021-06-17 2021-10-08 大连理工大学 漏斗型氮化镓纳米线及其制备方法
CN114695584A (zh) * 2021-12-23 2022-07-01 中山大学 一种超晶格纳米线、光电探测器及其制备方法
CN115128423A (zh) * 2022-06-30 2022-09-30 哈尔滨工业大学 一种重离子辐照影响β-Ga2O3 MOSFET器件电学性能的模拟方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110253982A1 (en) * 2008-10-28 2011-10-20 The Regents Of The University Of California Vertical group iii-v nanowires on si, heterostructures, flexible arrays and fabrication
CN104576928A (zh) * 2013-10-18 2015-04-29 中国科学院苏州纳米技术与纳米仿生研究所 一种有机/GaN异质p-n结紫外光探测器及其制备方法
CN106770598A (zh) * 2016-12-08 2017-05-31 东莞理工学院 Pd纳米线修饰电极及其制备方法和用途
WO2017195118A1 (en) * 2016-05-10 2017-11-16 King Abdullah University Of Science And Technology Light emitters on transition metal dichalcogenides directly converted from thermally and electrically conductive substrates and method of making the same
CN108735858A (zh) * 2018-04-11 2018-11-02 湖北大学 一种复合纳米结构的紫外/红外光电探测器制备方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110253982A1 (en) * 2008-10-28 2011-10-20 The Regents Of The University Of California Vertical group iii-v nanowires on si, heterostructures, flexible arrays and fabrication
CN104576928A (zh) * 2013-10-18 2015-04-29 中国科学院苏州纳米技术与纳米仿生研究所 一种有机/GaN异质p-n结紫外光探测器及其制备方法
WO2017195118A1 (en) * 2016-05-10 2017-11-16 King Abdullah University Of Science And Technology Light emitters on transition metal dichalcogenides directly converted from thermally and electrically conductive substrates and method of making the same
CN106770598A (zh) * 2016-12-08 2017-05-31 东莞理工学院 Pd纳米线修饰电极及其制备方法和用途
CN108735858A (zh) * 2018-04-11 2018-11-02 湖北大学 一种复合纳米结构的紫外/红外光电探测器制备方法

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
KAMIMURA JUMPEI, BOGDANOFF PETER, LÄHNEMANN JONAS, HAUSWALD CHRISTIAN, GEELHAAR LUTZ, FIECHTER SEBASTIAN, RIECHERT HENNING: "Photoelectrochemical Properties of (In,Ga)N Nanowires for Water Splitting Investigated by in Situ Electrochemical Mass Spectroscopy", JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, AMERICAN CHEMICAL SOCIETY, vol. 135, no. 28, 17 July 2013 (2013-07-17), pages 10242 - 10245, XP055815178, ISSN: 0002-7863, DOI: 10.1021/ja404043k *
WANG DANHAO, HUANG CHEN, LIU XIN, ZHANG HAOCHEN, YU HUABIN, FANG SHI, OOI BOON S., MI ZETIAN, HE JR‐HAU, SUN HAIDING: "Highly Uniform, Self‐Assembled AlGaN Nanowires for Self‐Powered Solar‐Blind Photodetector with Fast‐Response Speed and High Responsivity", ADVANCED OPTICAL MATERIALS, WILEY, DE, vol. 9, no. 4, 1 February 2021 (2021-02-01), DE, pages 2000893, XP055815188, ISSN: 2195-1071, DOI: 10.1002/adom.202000893 *
ZHANG MINGXIANG, YING LIU, MENGQI YANG, WEN ZHANG, JINYUAN ZHOU, ZHENXING ZHANG, ERQING XIE, XIAOJUN PAN, SHIBO LI: "High performance self-powered ultraviolet photodetectors based on electrospun gallium nitride nanowires", APPLIED SURFACE SCIENCE, vol. 452, 27 April 2018 (2018-04-27), pages 43 - 48, XP055815183, DOI: 10.1016/j.apsusc.2018.04.225 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113488433A (zh) * 2021-06-17 2021-10-08 大连理工大学 漏斗型氮化镓纳米线及其制备方法
CN113488433B (zh) * 2021-06-17 2024-06-07 大连理工大学 漏斗型氮化镓纳米线及其制备方法
CN114695584A (zh) * 2021-12-23 2022-07-01 中山大学 一种超晶格纳米线、光电探测器及其制备方法
CN115128423A (zh) * 2022-06-30 2022-09-30 哈尔滨工业大学 一种重离子辐照影响β-Ga2O3 MOSFET器件电学性能的模拟方法

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