Self-driven solar blind ultraviolet detector and preparation method thereof

Abstract

The invention relates to the technical field of semiconductor photoelectric detectors, in particular to a self-driven solar-blind ultraviolet detector and a preparation method thereof, and the self-driven solar-blind ultraviolet detector sequentially comprises a substrate, a BaTiO3 layer and a solar-blind photosensitive layer from bottom to top; the BaTiO3 layer is provided with a first electrode, and the solar-blind photosensitive layer is provided with a second electrode; the solar blind photosensitive layer comprises a plurality of cylinders arranged in a cylindrical array, and each cylinder is independently provided with a second electrode; the first electrode is Au or Pt, and the second electrode is Al; the self-driven solar blind ultraviolet detector provided by the invention can work under 0 V bias voltage, namely a self-driven working mode; the device can also work under other non-zero bias voltage, and the bias voltage range is-50V to 50V; and high responsivity can be obtained under the working condition of 0 V.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor photoelectric detectors, and in particular to a self-driven solar-blind ultraviolet detector and a preparation method thereof. Background Art

[0002] Ultraviolet detectors are widely used in astronomy, combustion engineering, water purification, flame detection, biological effects, space communications, environmental pollution monitoring and other fields. Due to the strong absorption of the atmosphere, ultraviolet rays with wavelengths below 280nm in solar radiation are almost non-existent on the surface. This ultraviolet band is vividly called the solar-blind band. Solar-blind ultraviolet detectors working in this band are not affected by solar radiation, have higher sensitivity, and have outstanding advantages in weak signal detection.

[0003] Up to now, photomultiplier tubes and Si-based UV-enhanced avalanche detectors have long occupied the main body of the UV detector market. They have mature technology and relatively excellent performance. However, photomultiplier tubes usually require extremely high operating voltages, are huge in size, and are easily disturbed by magnetic fields. Since Si-based UV-enhanced avalanche detectors respond to visible light, they need to be equipped with expensive filters to eliminate this effect when working as UV detectors, and usually have to work in a low-temperature environment to obtain high sensitivity.

[0004] At present, the demand for ultraviolet photodetectors with low energy consumption and high response speed is becoming more and more urgent. In this context, self-driven photodetectors that can work without external power supply have become an important research and development direction. The most common way to achieve self-driven photodetection is to separate photogenerated electron-hole pairs using the built-in electric field formed by PN (or PIN) junction or Schottky junction. However, these methods still face problems such as difficult preparation and poor performance.

[0005] In recent years, ferroelectric materials, such as barium titanate (BaTiO3) and strontium titanate (SrTiO3), have attracted more and more attention from researchers in the fields of photoelectric conversion and photovoltaic technology due to their unique ferroelectric spontaneous polarization properties. Introducing ferroelectric materials and their spontaneous polarization effects into wide-bandgap semiconductor Schottky junction self-driven day-blind ultraviolet detectors can undoubtedly enhance the built-in electric field and thus improve the photoelectric performance of the device. Summary of the invention

[0006] In view of this, the present invention aims to provide a self-driven solar-blind ultraviolet detector and a preparation method thereof to solve the problems existing in the prior art.

[0007] To achieve the above object, the technical solution created by the present invention is implemented as follows: A self-driven solar-blind ultraviolet detector, which comprises, from bottom to top, a substrate, a BaTiO3 layer and a solar-blind photosensitive layer; the BaTiO3 layer is provided with a first electrode, and the solar-blind photosensitive layer is provided with a second electrode; the solar-blind photosensitive layer comprises a plurality of cylinders arranged in a cylinder array, and each of the cylinders is independently provided with the second electrode; the solar-blind photosensitive layer is Ga2O3, ZnGa2O4, MgGa2O4 or ZnGaMgO alloy; the first electrode is Al, and the second electrode is Au or Pt.

[0008] Furthermore, the substrate is sapphire or Si; the thickness of the first electrode is greater than 20 nm and less than 100 nm; the thickness of the second electrode is greater than 20 nm and less than 100 nm.

[0009] Furthermore, the second electrode is a circular structure, a grid structure, or a single-finger structure.

[0010] Furthermore, the diameter of the cylinder ranges from 0.1 mm to 5 mm; the thickness of the cylinder ranges from 100 nm to 500 nm.

[0011] Furthermore, the distance between the first electrode and each of the second electrodes is 2 μm to 5 μm.

[0012] The present invention also provides a method for preparing the self-driven solar-blind ultraviolet detector, the method comprising the steps of: S1. The substrate is placed in a magnetron sputtering device, and radio frequency magnetron sputtering is performed at a temperature of 420°C to 650°C using a BaTiO3 ceramic target; the growth time of the radio frequency magnetron sputtering is 0.5h to 3h; post-annealing is performed at a temperature of 700°C to 900°C; the post-annealing time is 10min to 1h; S2. After the substrate with the grown BaTiO3 layer is cleaned, a solar-blind photosensitive layer is grown in a metal organic vapor deposition device; S3. etching the solar-blind photosensitive layer into a plurality of cylinders by photolithography and etching; S4. Prepare the first electrode on the surface of the BaTiO3 layer, and prepare the second electrode on the surface of the cylinder to obtain the self-driven solar-blind ultraviolet detector.

[0013] Furthermore, the substrate is first cleaned with trichloroethylene, acetone, and ethanol respectively, and then dried with nitrogen; the cleaning of the substrate on which the BaTiO3 layer is grown includes cleaning with oxygen plasma, the cleaning power is 60W to 100W, and the cleaning time is 1min to 20min; the etching reagent is hydrochloric acid, phosphoric acid, or a mixture of hydrochloric acid and phosphoric acid, and the concentration of the etching reagent is 0.01mol / L to 0.1mol / L.

[0014] Furthermore, the working gas in the RF magnetron sputtering process is argon gas, and the flow rate of the argon gas is 5 sccm to 30 sccm; the sputtering pressure is 0.5 Pa to 1 Pa, and the sputtering power is 55 W to 80 W.

[0015] Furthermore, the process of growing the solar-blind photosensitive layer includes: The growth temperature in the metal organic vapor deposition equipment is adjusted to 500°C to 800°C, and the vacuum degree of the growth chamber is adjusted to 2 10 2 Pa~1 10 4 Pa, the flow rate of oxygen is 100 mL / min~1000 mL / min, at least one of a zinc source, a magnesium source or a gallium source is introduced to grow the solar-blind photosensitive layer; the zinc source is diethyl zinc, the magnesium source is dimethyl magnesium cyclopentane, and the gallium source is triethyl gallium; the carrier gas flow rate of the diethyl zinc pipeline is 0 mL / min~100 mL / min, the carrier gas flow rate of the dimethyl magnesium cyclopentane pipeline is 0 mL / min~100 mL / min, and the carrier gas flow rate of the triethyl gallium pipeline is 0 mL / min~100 mL / min.

[0016] Furthermore, the preferred orientation of the BaTiO3 layer is controlled by controlling the post-annealing conditions, and the preferred orientation includes no orientation, (111) orientation, and (001) orientation.

[0017] Compared with the prior art, the invention can achieve the following beneficial effects: The self-driven solar-blind ultraviolet detector provided by the present invention can work under 0 V bias voltage, that is, self-driven working mode; it can also work under other non-zero bias voltages, and the bias voltage range is -50V to 50V; and high responsiveness can be obtained under 0 V working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings: Figure 1 A schematic flow chart of a method for preparing a self-driven solar-blind ultraviolet detector according to Example 1 of the present invention; Figure 2 The XRD spectrum of the BaTiO3 layer of the self-driven solar-blind ultraviolet detector described in Example 1 of the present invention; Figure 3 The light response curve of the self-driven solar-blind ultraviolet detector described in Example 1 of the present invention at 0V is provided; Figure 4 The response time curve of the self-driven solar-blind ultraviolet detector described in Example 1 of the present invention at 0V is provided; Figure 5 The light response curve of the self-driven solar-blind ultraviolet detector described in Example 1 of the present invention at 10V is shown. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the invention more clear, the invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the invention and do not constitute a limitation of the invention.

[0020] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0021] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0022] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0023] In a specific embodiment of the present invention, a self-driven solar-blind ultraviolet detector is provided, which includes a substrate, a BaTiO3 layer and a solar-blind photosensitive layer from bottom to top; the BaTiO3 layer is provided with a first electrode, and the solar-blind photosensitive layer is provided with a second electrode; the solar-blind photosensitive layer includes a plurality of cylinders arranged in a cylinder array, and each cylinder is independently provided with the second electrode; the solar-blind photosensitive layer is Ga2O3, ZnGa2O4, MgGa2O4 or ZnGaMgO alloy, the first electrode is Al, and the second electrode is Au or Pt; by using these wide bandgap semiconductor oxides, it can correspond to the solar-blind band and is more suitable for growth on the BaTiO3 layer. The ferroelectric effect of the BaTiO3 layer can more easily enhance the performance of the self-driven solar-blind ultraviolet detector of the solar-blind photosensitive layer of these materials. Specifically, a plurality of cylinders are evenly distributed and perpendicular to the entire BaTiO3 layer; a plurality of cylinders arranged in a cylinder array can be 1 1~20 20; In a more preferred embodiment, the number of cylinders ranges from 5 5~20 20, each cylinder is an independent detector unit.

[0024] In a specific embodiment, the substrate is sapphire or Si; the thickness of the first electrode is greater than 20nm and less than 100nm; the thickness of the second electrode is greater than 20nm and less than 100nm. The second electrode can be a circular structure, a grid structure, or a single interdigital structure; the spacing between the first electrode and each of the second electrodes is 2μm to 5μm. The diameter of the cylinder ranges from 0.1mm to 5mm; the thickness of the cylinder ranges from 100nm to 500nm; cylinder spacing-cylinder diameter = 0.1mm~10mm; it can better avoid interference related to each cylinder, and facilitate preparation and testing.

[0025] The self-driven day-blind ultraviolet detector provided in the specific embodiment of the present invention can work under 0 V bias, that is, self-driven working mode; it can also work under other non-zero bias, the bias range is -50V to 50V; and high responsivity can be obtained under 0 V working conditions.

[0026] A specific embodiment of the present invention further provides a method for preparing the self-driven solar-blind ultraviolet detector, the method comprising the steps of: S1. Place the substrate in a magnetron sputtering device, and use a BaTiO3 ceramic target to perform radio frequency magnetron sputtering at a temperature of 420°C to 650°C; the working gas in the radio frequency magnetron sputtering process is argon, and the flow rate of the argon is 5sccm to 30sccm; the sputtering pressure is 0.5Pa to 1Pa, and the sputtering power is 55W to 80W; the growth time of radio frequency magnetron sputtering is 0.5h to 3h; post-annealing is performed at a temperature of 700°C to 900°C; the time of the post-annealing is 10min to 1h; the preferred orientation of the BaTiO3 layer is controlled by controlling the conditions of the post-annealing, and the annealing conditions specifically include the annealing temperature and time; the preferred orientation includes no orientation, (111) orientation, and (001) orientation; in a preferred embodiment, the substrate is first cleaned with trichloroethylene, acetone, and ethanol respectively, and then blown dry with dry nitrogen, and then placed in the magnetron sputtering device; S2. The substrate on which the BaTiO3 layer is grown is cleaned and placed in a metal organic vapor deposition device to grow a day-blind photosensitive layer; the substrate on which the BaTiO3 layer is grown is cleaned by oxygen plasma cleaning, the cleaning power is 60W to 100W, and the cleaning time is 1min to 20min; the process of growing the day-blind photosensitive layer comprises: The growth temperature in the metal organic vapor deposition equipment is adjusted to 500°C to 800°C, and the vacuum degree of the growth chamber is adjusted to 2 10 2 Pa~1 10 4 Pa, the flow rate of oxygen is 100 mL / min~1000 mL / min, at least one of zinc source, magnesium source or gallium source is introduced to grow the solar-blind photosensitive layer; the zinc source is diethyl zinc, the magnesium source is dimethyl magnesium cyclopentane, and the gallium source is triethyl gallium; the carrier gas flow rate of the diethyl zinc pipeline is 0 mL / min~100 mL / min, the carrier gas flow rate of the dimethyl magnesium cyclopentane pipeline is 0 mL / min~100 mL / min, and the carrier gas flow rate of the triethyl gallium pipeline is 0 mL / min~100 mL / min, and the solar-blind photosensitive layer is grown; by controlling different pipelines to introduce gallium source, zinc source, and magnesium source with different flow rates, for example, simply introducing a gallium source, introducing a gallium source and a zinc source at the same time, introducing a gallium source and a magnesium source at the same time, or introducing a gallium source, a zinc source, and a magnesium source at the same time, different solar-blind photosensitive layers can be obtained as Ga2O3, ZnGa2O4, MgGa2O4 or ZnGaMgO alloy respectively; S3. Etch the day-blind photosensitive layer into a plurality of columns by photolithography and etching; the etching reagent is hydrochloric acid, phosphoric acid, or a mixture of hydrochloric acid and phosphoric acid, and the concentration of the etching reagent is 0.01mol / L to 0.1mol / L; specifically, the photolithography step may include: first applying photoresist, then covering some areas with a photomask with a pattern, then irradiating with ultraviolet light, and then soaking with a developer, at this time, a part of the photoresist area is not irradiated with ultraviolet light because of the pattern covering in the photomask, and this part of the area will react with the developer and appear hollowed out. After the photoresist is hollowed out, the day-blind photosensitive layer below will be exposed; at this time, etching the day-blind photosensitive layer again can etch away the day-blind photosensitive layer below the hollowed-out area to obtain a plurality of columns.

[0027] S4. The first electrode is prepared on the surface of the BaTiO3 layer outside the cylinder, and the second electrode is prepared on the surface of the cylinder to obtain the self-driven day-blind ultraviolet detector; specifically, the electrodes can be prepared by alignment photolithography and metal deposition, for example, using negative photoresist and a lift-off process, and observing under a microscope to align the electrode pattern with the cylinder pattern.

[0028] Through the preparation method of the specific embodiment of the present invention, it can be ensured that the size of each cylinder is uniform, the intervals are the same, and they are arranged vertically; thereby, it can be ensured that the performance of each detector unit is substantially the same.

[0029] The present invention is further described in detail below in conjunction with embodiments, but this description does not constitute a limitation of the present invention.

[0030] Example 1 like Figure 1 As shown, it is a schematic flow chart of the preparation method of the self-driven day-blind ultraviolet detector of this embodiment. It can be seen from the figure that the preparation method of the self-driven day-blind ultraviolet detector of this embodiment includes the steps of: (1) Use trichloroethylene, acetone, and ethanol to clean the sapphire substrate respectively, and then blow it dry with dry nitrogen.

[0031] (2) Place the substrate in step (1) in a magnetron sputtering device and perform radio frequency magnetron sputtering at 550 degrees using a BaTiO3 ceramic target. Select argon as the working gas, the gas flow rate is 20 sccm, the sputtering pressure is 1.5 Pa, the sputtering power is 55 W, and the growth time is 1.5 h. Then, post-annealing is performed at 800 degrees for 0.5 h.

[0032] (3) The surface of the substrate on which BaTiO3 was grown in step (2) was cleaned using oxygen plasma. The cleaning conditions were: power 85 W, time 10 min.

[0033] (4) Place the cleaned BaTiO3 in step (3) into a metal organic vapor deposition (MOCVD) device, adjust the growth temperature to 700 degrees, and the vacuum degree of the growth chamber to 1 103 Pa, oxygen flow rate of 450 mL / min, triethylgallium as gallium source. The carrier gas flow rate of triethylgallium pipeline is 20 mL / min, and the solar-blind photosensitive layer Ga2O3 material is grown.

[0034] (5) The thin film obtained in step (4) is subjected to photolithography and etching to etch the Ga2O3 layer into independent Ga2O3 cylinders, wherein the diameter of the Ga2O3 cylinder is 2 mm, and the etching reagent is a mixed solution of 0.05 mol / L hydrochloric acid and 0.05 mol / L phosphoric acid.

[0035] (6) The thin film obtained in step (5) is subjected to alignment photolithography and metal deposition to prepare an electrode on the surface of the Ga2O3 layer; another electrode is prepared on the surface of the BaTiO3 layer outside the Ga2O3 cylinder, and finally a self-driven day-blind ultraviolet detector is obtained. The electrode material on the Ga2O3 surface is Au and the shape is circular. The electrode material on the BaTiO3 surface is Al. The distance between the electrode on the BaTiO3 surface and the Ga2O3 cylinder is 2 microns.

[0036] Finally, a self-driven solar-blind UV detector with Au / Ga2O3 / BaTiO3 / Al structure was obtained. The XRD spectrum of the prepared BaTiO3 layer is shown in Figure 2 As shown in the figure, it can be seen that the BaTiO3 layer is (001) oriented.

[0037] The response curve of the self-driven solar-blind UV detector under 0 V conditions is shown in Figure 3 As shown in the figure, it can be seen that the response of the self-driven solar-blind ultraviolet detector of this embodiment can reach 251 mA / W, and the solar-blind suppression ratio is 6.7 10 3 , UV-visible suppression ratio 3.3 10 4 .

[0038] Under 0 V conditions, the response time spectrum of the self-driven solar-blind UV detector is as follows Figure 4 As shown in the figure, it can be seen that the rise time of the self-driven solar-blind ultraviolet detector is 10 ns and the fall time is 20 ns.

[0039] The response curve of the self-driven solar-blind UV detector under 10 V conditions is shown in Figure 5 As shown in the figure, it can be seen that the response of the self-driven solar-blind UV detector can reach 430 amperes / watt (A / W), and the solar-blind suppression ratio is 8.3 103 , UV-visible suppression ratio 3.1 10 7 .

[0040] Example 2 In order to compare the performance of the corresponding self-driven solar-blind ultraviolet detectors with different solar-blind photosensitive layers, this embodiment only changes the preparation method of the solar-blind photosensitive layer, and the other conditions are exactly the same as those in Example 1. The preparation method of the solar-blind photosensitive layer is: put the BaTiO3 cleaned in step (3) into a metal organic vapor deposition (MOCVD) device, adjust the growth temperature to 700 degrees, and the vacuum degree of the growth chamber to 1 10 3 Pa, the oxygen flow rate is 450 mL / min, diethyl zinc is used as the zinc source, dimethyl magnesium cyclopentane is used as the magnesium source, and triethyl gallium is used as the gallium source; the carrier gas flow rate of the diethyl zinc pipeline is 10 mL / min, the carrier gas flow rate of the dimethyl magnesium cyclopentane pipeline is 5 mL / min, and the carrier gas flow rate of the triethyl gallium pipeline is 20 mL / min, and the solar-blind photosensitizing layer ZnMgGaO alloy is grown.

[0041] Finally, a self-driven solar-blind UV detector with Au / ZnMgGaO / BaTiO3 / Al structure was obtained. The responsivity of the self-driven solar-blind UV detector under 0 V conditions can reach 52 mA / W, and the solar-blind suppression ratio is 4.2. 10 3 , UV-visible suppression ratio 1.3 10 4 Under 0 V conditions, the rise time of the self-driven solar-blind UV detector is 10 ns and the fall time is 20 ns; the responsivity of the self-driven solar-blind UV detector under 10 V conditions can reach 30 amperes / watt (A / W), and the solar-blind suppression ratio is 2.3 10 3 , UV-visible suppression ratio 1.0 10 7 .

[0042] Example 3 In order to compare the performance of the corresponding self-driven solar-blind ultraviolet detectors with different solar-blind photosensitive layers, this embodiment only changes the preparation method of the solar-blind photosensitive layer, and the other conditions are exactly the same as those in Example 1. The preparation method of the solar-blind photosensitive layer is: put the BaTiO3 cleaned in step (3) into a metal organic vapor deposition (MOCVD) device, adjust the growth temperature to 700 degrees, and the vacuum degree of the growth chamber to 1 10 3Pa, the oxygen flow rate is 450 mL / min, diethylzinc is used as the zinc source, and triethylgallium is used as the gallium source; the carrier gas flow rate of the diethylzinc pipeline is 10 mL / min, and the carrier gas flow rate of the triethylgallium pipeline is 20 mL / min, and the solar-blind photosensitive layer ZnGa2O4 is grown.

[0043] Finally, a self-driven solar-blind UV detector with Au / ZnGa2O4 / BaTiO3 / Al structure was obtained. The response of the self-driven solar-blind UV detector under 0 V conditions can reach 255 mA / W, and the solar-blind suppression ratio is 7.3. 10 3 , UV-visible suppression ratio 6.3 10 4 Under 0 V conditions, the rise time of the self-driven solar-blind UV detector is 10 ns and the fall time is 20 ns; the responsivity of the self-driven solar-blind UV detector under 10 V conditions can reach 408 amperes / watt (A / W), and the solar-blind suppression ratio is 5.3 10 3 , UV-visible suppression ratio 3.1 10 7 .

[0044] Example 4 In order to compare the performance of the self-driven solar-blind ultraviolet detectors with different solar-blind photosensitive layers, this embodiment only changes the preparation method of the solar-blind photosensitive layer, and the other conditions are exactly the same as those in Example 1. The preparation method of the solar-blind photosensitive layer is as follows: put the BaTiO3 cleaned in step (3) into a metal organic vapor deposition (MOCVD) device. Adjust the growth temperature to 700 degrees and the vacuum degree of the growth chamber to 1 10 3 Pa, the oxygen flow rate is 450 mL / min, dimethylmagnesium cyclopentadienyl is used as the magnesium source, and triethylgallium is used as the gallium source. The carrier gas flow rate of dimethylmagnesium cyclopentadienyl is 12 mL / min, and the carrier gas flow rate of the triethylgallium pipeline is 20 mL / min, and the solar-blind photosensitive layer MgGa2O4 is grown.

[0045] Finally, a self-driven solar-blind UV detector with Au / MgGa2O4 / BaTiO3 / Al structure was obtained. The response of the self-driven solar-blind UV detector under 0 V conditions can reach 45 mA / W, and the solar-blind suppression ratio is 1.3. 10 3 , UV-visible suppression ratio 2.1 10 4 , under 0 V conditions, the rise time of the self-driven solar-blind UV detector is 10 ns and the fall time is 20 ns. The responsivity of the self-driven solar-blind UV detector under 10 V conditions can reach 14 amperes / watt (A / W), and the solar-blind rejection ratio is 1.1 10 3 , UV-visible suppression ratio 1.7 10 7 .

[0046] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A self-driven solar-blind ultraviolet detector, characterized in that: The self-driven solar-blind ultraviolet detector comprises, from bottom to top, a substrate, a BaTiO3 layer and a solar-blind photosensitive layer; the BaTiO3 layer is provided with a first electrode, and the solar-blind photosensitive layer is provided with a second electrode; the solar-blind photosensitive layer comprises a plurality of cylinders arranged in a cylinder array, and each cylinder is independently provided with the second electrode; The solar-blind photosensitive layer is Ga2O3, ZnGa2O4, MgGa2O4 or ZnGaMgO alloy; The first electrode is Al, and the second electrode is Au or Pt.

2. The self-driven solar-blind ultraviolet detector according to claim 1, characterized in that: The substrate is sapphire or Si; the thickness of the first electrode is greater than 20 nm and less than 100 nm; the thickness of the second electrode is greater than 20 nm and less than 100 nm.

3. The self-driven solar-blind ultraviolet detector according to claim 1, characterized in that: The second electrode is a circular structure, a grid structure, or a single-finger structure.

4. The self-driven solar-blind ultraviolet detector according to claim 1, characterized in that: The diameter of the cylinder ranges from 0.1 mm to 5 mm; the thickness of the cylinder ranges from 100 nm to 500 nm.

5. The self-driven solar-blind ultraviolet detector according to claim 1, characterized in that: The distance between the first electrode and each of the second electrodes is 2 μm to 5 μm.

6. A method for preparing a self-driven solar-blind ultraviolet detector according to any one of claims 1 to 5, characterized in that: The preparation method comprises the steps of: S1. The substrate is placed in a magnetron sputtering device, and radio frequency magnetron sputtering is performed at a temperature of 420°C to 650°C using a BaTiO3 ceramic target; the growth time of the radio frequency magnetron sputtering is 0.5 h to 3 h; post-annealing is performed at a temperature of 700°C to 900°C; the post-annealing time is 10 min to 1 h; S2. After the substrate with the grown BaTiO3 layer is cleaned, it is placed in a metal organic vapor deposition device to grow a solar-blind photosensitive layer; S3. etching the solar-blind photosensitive layer into a plurality of cylinders by photolithography and etching; S4. Prepare the first electrode on the surface of the BaTiO3 layer, and prepare the second electrode on the surface of the cylinder to obtain the self-driven solar-blind ultraviolet detector.

7. The method for preparing the self-driven solar-blind ultraviolet detector according to claim 6, characterized in that: The substrate is first cleaned with trichloroethylene, acetone and ethanol respectively, and then blown dry with nitrogen; the cleaning of the substrate with the grown BaTiO3 layer includes cleaning with oxygen plasma, the cleaning power is 60W~100W, and the cleaning time is 1min~20min; the etching reagent is hydrochloric acid, phosphoric acid, or a mixture of hydrochloric acid and phosphoric acid, and the concentration of the etching reagent is 0.01mol / L~0.1mol / L.

8. The method for preparing the self-driven solar-blind ultraviolet detector according to claim 6, characterized in that: The working gas in the RF magnetron sputtering process is argon gas, and the flow rate of the argon gas is 5 sccm to 30 sccm; the sputtering pressure is 0.5 Pa to 1 Pa, and the sputtering power is 55 W to 80 W.

9. The method for preparing the self-driven solar-blind ultraviolet detector according to claim 6, characterized in that: The process of growing the solar-blind photosensitive layer includes: The growth temperature in the metal organic vapor deposition equipment is adjusted to 500°C to 800°C, and the vacuum degree of the growth chamber is adjusted to 2 10 2 Pa~1 10 4 Pa, the flow rate of oxygen is 100 mL / min to 1000 mL / min, at least one of a zinc source, a magnesium source or a gallium source is introduced to grow the solar-blind photosensitive layer; the zinc source is diethyl zinc, the magnesium source is dimethyl magnesium cyclopentane, and the gallium source is triethyl gallium; the carrier gas flow rate of the diethyl zinc pipeline is 0 mL / min to 100 mL / min, the carrier gas flow rate of the dimethyl magnesium cyclopentane pipeline is 0 mL / min to 100 mL / min, and the carrier gas flow rate of the triethyl gallium pipeline is 0 mL / min to 100 mL / min, and the solar-blind photosensitive layer is grown.

10. The method for preparing the self-driven solar-blind ultraviolet detector according to claim 6, characterized in that: The preferred orientation of the BaTiO3 layer is controlled by controlling the post-annealing conditions, and the preferred orientation includes no orientation, (111) orientation, and (001) orientation.

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