An ultraviolet photoelectric sensor based on surface ion transport, its fabrication method and application

Abstract

This invention discloses an ultraviolet photoelectric sensor based on surface ion transport, its fabrication method, and its application, belonging to the field of photoelectric sensor technology. The ultraviolet photoelectric sensor includes a wide-bandgap semiconductor substrate with hydrophilic properties, a porous hydrophilic material disposed on the substrate surface, and a non-polarized electrode; a power supply and a meter are connected to the non-polarized electrode circuit. In a high-humidity environment, a continuous water film is adsorbed on the substrate surface, providing ionic conductivity. The porous hydrophilic material prevents water from spreading on the substrate surface, and the non-polarized electrode can rapidly convert the ionic current into a detectable electronic current. The ultraviolet photoelectric sensor provided by this invention utilizes the ionic conductivity of the continuous water film and the temperature change caused by the absorption of ultraviolet light by the wide-bandgap semiconductor to achieve the detection of ultraviolet light. Compared with traditional ultraviolet photoelectric sensors, this invention has the advantages of simple fabrication and suitability for operation in high-humidity environments.

Description

Technical Field

[0001] This invention belongs to the field of ultraviolet photoelectric sensor technology, specifically relating to an ultraviolet photoelectric sensor based on surface ion transport, its preparation method, and its application. Background Technology

[0002] An ultraviolet photoelectric sensor is a device that can convert ultraviolet light signals into measurable electrical signals and detect ultraviolet light by detecting changes in the electrical signals. It is widely used in environmental monitoring, fire early warning, space exploration, chemical detection, biological detection, and wireless communication.

[0003] The development of ultraviolet (UV) photoelectric sensors has gone through three significant stages: photomultiplier tubes (PMTs), silicon-based UV photodiodes, and the latest wide-bandgap semiconductor UV photoelectric sensors. PMTs, due to their large size, high power consumption, and requirement for high voltage operation, are often used in military applications. While silicon-based UV photoelectric sensors are widely used, they are prone to aging under UV irradiation, and their narrow bandgap necessitates filters to distinguish between UV and visible light, increasing overall cost. Given the limitations of these two sensor configurations, researchers are increasingly turning to the development of third-generation UV photoelectric sensors—those based on wide-bandgap semiconductors such as TiO2, ZnO, GaN, and β-Ga2O3.

[0004] Wide bandgap semiconductors possess a sufficiently large bandgap to effectively filter visible light, thus eliminating the need for additional filters and overcoming the shortcomings of previous generations of products. Current wide bandgap semiconductor ultraviolet photoelectric sensors are mainly divided into two types: photoconductive sensors and photovoltaic sensors. Photoconductive sensors are current-output type, requiring an external bias voltage; while photovoltaic sensors are voltage-output type, requiring no external bias voltage. Furthermore, photoconductive sensors have a simpler configuration, requiring only a single semiconductor and two electrodes; while photovoltaic sensors are more complex, with various configurations such as Schottky, pn junction, pin junction, MIS, and MSM types.

[0005] It is worth noting that both of these wide-bandgap semiconductor ultraviolet sensors are based on electronic conductivity. When operating in environments containing water vapor, especially in high humidity environments, they need to be encapsulated; otherwise, they will generate large dark currents or even short-circuit failures. Summary of the Invention

[0006] 1. The problem to be solved

[0007] This invention addresses the problem of existing ultraviolet photoelectric sensors based on electronic conductivity requiring encapsulation in high-humidity environments. It provides an ultraviolet photoelectric sensor based on surface ion transport, its fabrication method, and its applications. This sensor utilizes ionic conductivity rather than electronic conductivity, leveraging the ionic conductivity of a continuous liquid film adsorbed on a hydrophilic surface and the temperature change caused by the absorption of ultraviolet light by a wide-bandgap semiconductor to achieve ultraviolet light detection. Compared to traditional electronic conductivity sensors, ionic conductivity offers higher reliability and eliminates the need for encapsulation in high-humidity environments.

[0008] 2. Technical Solution

[0009] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0010] This invention provides an ultraviolet photoelectric sensor based on surface ion transport, comprising:

[0011] Power supply, meter, substrate, first electrode and second electrode,

[0012] Both the first electrode and the second electrode include a porous hydrophilic material and a non-polarized electrode connected to the porous hydrophilic material; the porous hydrophilic material enables water to form a liquid film instead of spreading on the substrate surface, and the non-polarized electrode enables ionic current to be converted into electronic current.

[0013] The porous hydrophilic materials of the first and second electrodes are disposed on the substrate surface.

[0014] The non-polarized electrodes of the first and second electrodes are connected to the power supply and the meter through a circuit.

[0015] in:

[0016] The substrate includes a wide bandgap semiconductor with strong hydrophilic properties. Strong hydrophilicity means a contact angle of less than or equal to 30°, and wide bandgap semiconductor means a semiconductor with a bandgap width of greater than or equal to 3.2 eV. This wide bandgap semiconductor can effectively filter visible light.

[0017] The aqueous solutions adsorbed by porous hydrophilic materials include both anions and cations.

[0018] Furthermore, the aforementioned porous hydrophilic material does not come into contact with the substrate boundary.

[0019] Furthermore, the aforementioned base material is selected from any one of muscovite, biotite, vermiculite, and kaolinite.

[0020] Furthermore, the substrate material is selected from muscovite, and its quality is V1 grade. Compared with other grades of mica sheets, V1 grade mica has fewer impurities and more stable surface ionic conductivity.

[0021] Furthermore, the shape of the substrate includes rectangles, squares, circles, etc.; as a further explanation of the present invention, the present invention does not limit the shape of the substrate, which can be a porous hydrophilic material for setting the first electrode and the second electrode.

[0022] Furthermore, the thickness of the substrate is 10~200 μm; as a further explanation of the present invention, the present invention does not limit the substrate thickness, as long as the substrate is completely peeled off.

[0023] Furthermore, the thickness of the aforementioned substrate is 50~200 μm.

[0024] Furthermore, the thickness of the aforementioned substrate is 100~200 μm.

[0025] Furthermore, the thickness of the substrate is 100~130 μm. As a further explanation of the present invention, the substrate thickness is related to the light absorption and the temperature rise. The smaller the thickness, the smaller the light absorption and the smaller the temperature change. The larger the thickness, the greater the light absorption required to raise the temperature by the same amount. Therefore, the substrate thickness needs to be as thick as possible. However, the applicant's research found that the temperature change decreases when the substrate thickness exceeds 130 μm. Therefore, it is preferable not to exceed 130 μm.

[0026] Furthermore, the thickness of the aforementioned substrate includes 110~130 μm.

[0027] Furthermore, the thickness of the aforementioned substrate includes 120~130 μm.

[0028] Furthermore, the thickness of the aforementioned substrate is 130 μm.

[0029] Furthermore, the aforementioned porous hydrophilic material is selected from any one or more of artificial hydrogels, natural hydrogels, and solid electrolytes.

[0030] Furthermore, the aforementioned hydrogel includes any one or more of the following: polyacrylamide (PAAM) hydrogel, polyvinyl alcohol (PVA) hydrogel, etc.

[0031] Furthermore, the shape of the aforementioned porous hydrophilic material includes rectangles, squares, circles, etc.; as a further explanation of the present invention, the present invention does not limit the shape of the porous hydrophilic material, which can be disposed on the substrate surface and does not extend beyond the substrate surface. However, as a preferred embodiment, the porous hydrophilic material is set to a regular shape, such as a rectangle, which makes its manufacturing more convenient.

[0032] Furthermore, the distance between the porous hydrophilic materials of the first electrode and the second electrode is 10~50 mm; as a further explanation of the present invention, the distance refers to the closest distance between the two, such as the distance between the two closest sides of a rectangular porous hydrophilic material arranged in parallel; the distance between the porous hydrophilic materials of the first electrode and the second electrode is related to the conductivity and temperature rise. The closer the distance, the greater the conductivity under the same voltage; while the farther the distance, the more obvious the temperature rise in the central region due to the large specific heat capacity of the hydrogel. The distance setting in the present invention can improve the on / off ratio of the sensor.

[0033] Furthermore, the distance between the porous hydrophilic materials of the first electrode and the second electrode is 30~50 mm.

[0034] Furthermore, the distance between the porous hydrophilic materials of the first electrode and the second electrode is 40 mm; as a further explanation of the present invention, the on / off ratio is at its maximum at this time.

[0035] Furthermore, the aforementioned non-polarized electrode is selected from silver / silver chloride electrode, calomel electrode, or copper / copper sulfate electrode.

[0036] Furthermore, the aforementioned non-polarized electrode is selected from silver / silver chloride electrodes.

[0037] Furthermore, the voltage of the aforementioned power supply includes 0.2~2 V.

[0038] Furthermore, the voltage of the aforementioned power supply includes 0.2~1.5 V.

[0039] Furthermore, the aforementioned meter includes a picoammeter, which can measure currents from 20 fA to 20 mA. As a further explanation of the present invention, the present invention does not limit the model of the meter, as long as it can meet the requirements for measuring small currents.

[0040] Furthermore, the anions in the aqueous solution adsorbed by the above-mentioned porous hydrophilic material are selected from Cl... - ,Br - I - Any one or more of the following.

[0041] Furthermore, the cations in the aqueous solution adsorbed by the above-mentioned porous hydrophilic material are selected from K + Na + Li + Any one or more of the following.

[0042] Furthermore, the cations in the aqueous solution adsorbed by the above-mentioned porous hydrophilic material are selected from K + As a further explanation of the present invention, the mica (white mica, biotite) material contains K + K was selected + It helps to improve ionic conductivity.

[0043] Furthermore, the anions and cations in the aqueous solution adsorbed by the above porous hydrophilic material are Cl- and Cl-, respectively. - and K + .

[0044] This invention also provides a method for fabricating the aforementioned ultraviolet photoelectric sensor based on surface ion transport, the method comprising the following steps:

[0045] S01, prepare a power supply, a meter, a non-polarized electrode, and a wide bandgap semiconductor substrate with strong hydrophilic properties of the target shape, and a porous hydrophilic material that adsorbs aqueous solutions containing anions and cations; strong hydrophilic properties refer to a contact angle of the wide bandgap semiconductor being less than or equal to 30°, and a wide bandgap semiconductor is a semiconductor with a bandgap width greater than or equal to 3.2 eV.

[0046] S02, connect the non-polarized electrode to the porous hydrophilic material to form the first electrode and the second electrode, and place them on the substrate surface according to the distance, the distance between the porous hydrophilic materials of the first electrode and the second electrode is 10~50 mm;

[0047] S03, the non-polarized electrodes of the first and second electrodes are connected to the power supply and the meter through a circuit to form an ultraviolet photoelectric sensor based on surface ion transport.

[0048] Furthermore, the target shape of the aforementioned wide bandgap semiconductor substrate includes rectangles, squares, circles, etc.; as a further explanation of the present invention, the present invention does not limit the shape of the substrate and the porous hydrophilic material, and the porous hydrophilic materials of the first electrode and the second electrode can be disposed on the substrate surface, as long as they do not extend beyond the substrate surface.

[0049] Furthermore, the voltage of the aforementioned power supply includes 0.2~2 V.

[0050] Furthermore, the voltage of the aforementioned power supply includes 0.2~1.5 V.

[0051] Furthermore, the aforementioned meter includes a picoammeter, which can measure currents from 20 fA to 20 mA. As a further explanation of the present invention, the present invention does not limit the model of the meter, as long as it can meet the requirements for measuring small currents.

[0052] Furthermore, the aforementioned non-polarized electrode is selected from silver / silver chloride electrode, calomel electrode, or copper / copper sulfate electrode.

[0053] Furthermore, the aforementioned non-polarized electrode is selected from silver / silver chloride electrodes.

[0054] Furthermore, the preparation method of the above-mentioned silver / silver chloride electrode includes: carrying out a redox reaction of a high-purity silver mesh in a potassium chloride solution to prepare a silver / silver chloride electrode.

[0055] Furthermore, the purity of the aforementioned high-purity silver mesh should be greater than 99.99%. As a further explanation of the present invention, a silver mesh of this purity can reduce impurities and improve electrode stability.

[0056] Furthermore, the aforementioned base material is selected from any one of muscovite, biotite, vermiculite, and kaolinite.

[0057] Furthermore, the aforementioned substrate material is selected from muscovite.

[0058] Furthermore, the base of the aforementioned target shape is formed by cutting out the base.

[0059] Furthermore, the aforementioned porous hydrophilic material is selected from any one or more of artificial hydrogels, natural hydrogels, and solid electrolytes.

[0060] Furthermore, the preparation of the porous hydrophilic material that adsorbs aqueous solutions containing anions and cations includes: placing the porous hydrophilic material in an aqueous solution containing anions and cations, fully absorbing water and exchanging ions.

[0061] Furthermore, the aforementioned aqueous solutions containing anions and cations include aqueous solutions containing any one or more of KCl, NaCl, LiCl, etc.

[0062] Furthermore, the above-mentioned aqueous solution containing anions and cations is a KCl aqueous solution.

[0063] This invention also provides an application of the aforementioned ultraviolet photoelectric sensor based on surface ion transport for detecting ultraviolet light.

[0064] Furthermore, the above-mentioned detection of ultraviolet light includes detecting ultraviolet light in an environment containing water vapor. As a further explanation of the present invention, when the ultraviolet photoelectric sensor based on surface ion transport detects ultraviolet light in a water vapor environment, a continuous water film is adsorbed on the surface of a wide bandgap semiconductor substrate with strong hydrophilic properties, thus providing ion conductivity channels. However, if water is directly spread on the substrate surface, the surface conductivity of the substrate will be extremely high and unstable, and the photothermal effect will not be obvious (because water has a high specific heat capacity). At this time, due to the presence of porous hydrophilic materials of the first and second electrodes, the hydrophilic properties prevent water from spreading on the substrate surface and instead form nanochannels. In the electric field formed by the voltage provided by the power supply, anions and cations in the porous hydrophilic material move directionally under the action of the electric field to form a current. The non-polarized electrode can quickly convert the ion current into a detectable electronic current. When ultraviolet light irradiates the substrate, the substrate absorbs the ultraviolet light and heats up rapidly. The continuous water film adsorbed on the substrate surface evaporates due to the temperature change, thereby changing the size of the nanochannels and the ion mobility, which in turn causes a change in current. The change in current value is displayed by an ammeter. Therefore, the detection of ultraviolet light is achieved by detecting the change in current in the ammeter.

[0065] Furthermore, the aforementioned water vapor environment includes environments with a relative humidity of 20% or higher.

[0066] Furthermore, the aforementioned water vapor environment includes environments with a relative humidity of 40% or higher.

[0067] Furthermore, the aforementioned water vapor environment includes environments with a relative humidity of 60% or higher.

[0068] Furthermore, the aforementioned water vapor environment includes environments with a relative humidity of 80% or higher.

[0069] Furthermore, the aforementioned water vapor environment includes environments with a relative humidity of 90% or higher.

[0070] The present invention also provides a method for detecting ultraviolet light in the environment, the method comprising: placing the above-mentioned ultraviolet photoelectric sensor based on surface ion transport in the environment, and detecting ultraviolet light based on the change of current in the meter.

[0071] 3. Beneficial effects

[0072] Compared with the prior art, the advantages of this invention are as follows:

[0073] (1) This invention provides an ultraviolet photoelectric sensor based on surface ion transport and its application, especially for detecting ultraviolet light in high humidity environments, without the need for additional packaging. Furthermore, this ultraviolet photoelectric sensor uses photothermal effect and ion transport system as the basic principle and structure of the sensor. Compared with electronic conductivity-based electronic devices, ion conductivity-based electronic devices are more stable, filling a gap in related fields. Simultaneously, this ultraviolet photoelectric sensor uses a wide bandgap semiconductor as the substrate, eliminating the need for filters to detect ultraviolet light.

[0074] (2) The ultraviolet photoelectric sensor based on surface ion transport and its fabrication method provided by the present invention have a simple configuration and an economical and simple fabrication method, which does not require the use of nanofabrication technologies such as photolithography, etching, and deposition. In addition, the required materials are widely available and easy to obtain, and can be easily fabricated on a large scale, thus having the potential for large-scale industrial production. Attached Figure Description

[0075] Figure 1 This is a schematic diagram of the ultraviolet photoelectric sensor based on surface ion transport according to the present invention, wherein: A is a top view of the sensor and B is a front view of the sensor.

[0076] Figure 2 This is a schematic diagram of the preparation of the silver / silver chloride electrode of the present invention.

[0077] Figure 3This is a switching current diagram of the ultraviolet photoelectric sensor based on surface ion transport according to the present invention. Specifically, it shows the current and switching ratio under different powers of 365 nm ultraviolet light irradiation at a bias voltage of 0.2 V.

[0078] Figure 4 These are absorbance test data for a muscovite sample with a thickness of approximately 130 μm.

[0079] Figure 5 It is the detection result of the change in the on / off ratio when the distance between the first electrode and the second electrode is changed, all other things being equal.

[0080] Figure 6 The results show the temperature change of muscovite under ultraviolet light irradiation when the thickness of the muscovite is changed, all other things being equal.

[0081] In the figure: 1 is the substrate, 2 is the porous hydrophilic material, 3 is the non-polarized electrode, 4 is the high-purity silver mesh, and 5 is the platinum sheet electrode. Detailed Implementation

[0082] The present invention will be further described below with reference to specific embodiments.

[0083] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0084] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0085] As used herein, the term “about” is used to provide for the flexibility and imprecision associated with a given term, measure, or value. Those skilled in the art can readily determine the degree of flexibility for a particular variable.

[0086] As used herein, the term “at least one of…” is intended to be synonymous with “one or more of…”. For example, “at least one of A, B, and C” explicitly includes only A, only B, only C, and combinations thereof.

[0087] Concentration, amount, and other numerical data may be presented in range format herein. It should be understood that such range format is used solely for convenience and brevity and should be flexibly interpreted to include not only the values ​​explicitly stated as the limits of the range, but also all individual values ​​or subranges encompassed within the range, as if each value and subrange were explicitly stated. For example, a range of values ​​from about 1 to about 4.5 should be interpreted to include not only the explicitly stated limits of 1 to 4.5, but also individual numbers (such as 2, 3, 4) and subranges (such as 1 to 3, 2 to 4, etc.). The same principle applies to ranges that describe only a single value, such as "less than about 4.5," which should be interpreted to include all the values ​​and ranges described above. Furthermore, this interpretation should apply regardless of the breadth of the range or characteristic described.

[0088] As defined in this invention, unless otherwise specified, "ionic current" refers to the current formed by the directional movement of ions in an electrolyte solution or ionic conductor. "Electron current" refers to the current in a conductor where the charge carriers are electrons, formed by the directional movement of electrons.

[0089] As per this invention, unless otherwise specified, the current switching ratio is the current (Ion) when the device is in the on state. on ) and the current when it is in the off state (I) off The ratio of on / off ratio (I / I) can be expressed by the formula: On / off ratio = I / I on / I off The current switching ratio reflects the degree of change in electrical performance when a device switches between two states. The larger the ratio, the more significant the difference between the on and off states, and the better the switching performance.

[0090] Example 1

[0091] This embodiment provides an ultraviolet photoelectric sensor based on surface ion transport and its fabrication method.

[0092] The structure of an ultraviolet photoelectric sensor based on surface ion transport is as follows: Figure 1 As shown, it includes:

[0093] The device includes a power supply, an electricity meter, a wide bandgap semiconductor substrate 1 with strong hydrophilic properties, a first electrode, and a second electrode. Both the first electrode and the second electrode include a porous hydrophilic material 2 and a non-polarized electrode 3 connected to the porous hydrophilic material 2. The aqueous solution adsorbed by the porous hydrophilic material 2 includes anions and cations.

[0094] The porous hydrophilic material 2 of the first electrode and the second electrode is disposed on the surface of the substrate 1. In this embodiment, the porous hydrophilic material 2 is directly placed on the substrate 1, and the non-polarized electrodes 3 of the first electrode and the second electrode are connected to the power supply and the meter through a circuit.

[0095] In this embodiment, the wide bandgap semiconductor substrate 1 with strong hydrophilic properties is a V1 grade muscovite sheet, with a contact angle generally less than 10° and a bandgap width of approximately 6 eV. The porous hydrophilic material 2 is a polyacrylamide (PAAM) hydrogel, and the adsorbed aqueous solution includes Cl. - and K + The non-polarized electrode 3 is a silver / silver chloride electrode.

[0096] Its preparation method includes the following steps:

[0097] S01, prepare a power supply, a meter, a non-polarized electrode 3, and a wide bandgap semiconductor substrate 1 with strong hydrophilic properties of the target shape, and a porous hydrophilic material 2 that adsorbs aqueous solutions containing anions and cations.

[0098] S02, the non-polarized electrode 3 is connected to the porous hydrophilic material 2 to form the first electrode and the second electrode, and placed on the surface of the substrate 1 according to the distance.

[0099] S03, the non-polarized electrode 3 of the first electrode and the second electrode is connected to the power supply and the meter through a circuit to form an ultraviolet photoelectric sensor based on surface ion transport.

[0100] Specifically, it includes:

[0101] 1) Preparation of wide bandgap semiconductor substrate with strong hydrophilic properties: Select V1 grade mica sheet with a size of 75 mm × 25 mm. The manufacturer is TED PELLA. Use a scalpel to pry it open from the boundary and mechanically peel off a layer along the opening. The thickness is about 130 μm. Mica is a layered material. Using this method can minimize the steps on the mica surface to maintain the stability of ion transport on the mica surface.

[0102] 2) Preparation of porous hydrophilic materials for adsorbing aqueous solutions containing anions and cations: (a) Weigh 15.6376 g (0.22 mol) acrylamide (AAm) using an analytical balance; measure 100 mL of ultrapure water using a graduated cylinder; place the weighed AAM and ultrapure water into a beaker and stir magnetically to fully dissolve AAM. (b) Add 0.009384 g N-N'-methylenebispropylamide crosslinking agent (MBAA) and 0.026588 g ammonium persulfate (AP) photoinitiator to the beaker sequentially and stir evenly. (c) In a fume hood, use a pipette to measure 53 μL (0.0391 g) tetramethylethylenediamine (TEMED) crosslinking promoter (Aladdin, 0.775 g / mL, 96%), add it to the beaker and stir evenly. (d) Pour the prepared solution into a mold and cover it with a glass plate; remove it from the mold after the hydrogel has completely solidified. (e) Prepare a potassium chloride solution with a concentration of 1 mol / L; cut the prepared hydrogel into the required shape (approximately 10 mm × 20 mm), immerse the cut hydrogel in the potassium chloride solution, and use it after the hydrogel has completely absorbed water and swelled.

[0103] 3) Preparation of the non-polarized electrode (silver / silver chloride electrode): Connect a high-purity silver mesh (99.99%) to the positive terminal of the power supply, and a platinum sheet electrode to the negative terminal of the power supply. Place the silver mesh and platinum sheet electrode in a 0.1 M potassium chloride solution and maintain a bias voltage of 1.5 V for 30 minutes. Figure 2 After the reaction is complete, remove the silver / silver chloride mesh, blow it dry, and cut it into the desired shape, generally slightly smaller than the size of the hydrogel.

[0104] 4) Connect the silver / silver chloride electrode to the porous hydrophilic material (the silver / silver chloride electrode is placed directly on the porous hydrophilic material) to form the first electrode and the second electrode, and place them on the substrate surface according to the distance, with a spacing of 40 mm between the two hydrogels.

[0105] 5) The silver / silver chloride electrode is connected to an external power supply and a meter. The power supply is 0.2 V and the meter is a Keithley 6487 picoammeter to obtain an ultraviolet photoelectric sensor based on surface ion transport.

[0106] Example 2

[0107] This embodiment provides a study on the performance of the ultraviolet photoelectric sensor based on surface ion transport prepared in Example 1 in detecting ultraviolet light in a high humidity environment.

[0108] The ultraviolet photoelectric sensor based on surface ion transport prepared in Example 1 was placed in an aluminum box with controllable ambient humidity. After the water-containing environment stabilized for 30 minutes, the relative humidity was about 90%. A hole with a diameter of about 1 cm was made in the top of the aluminum box and sealed with a quartz window.

[0109] The light absorbance of the substrate was measured using a UV-Vis spectrophotometer after irradiation with UV lamps of different wavelengths. The light absorption range is as follows: Figure 4 As shown, muscovite has a large absorption in the ultraviolet band with wavelengths below 400 nm, so a 365 nm ultraviolet lamp was selected for subsequent experiments.

[0110] A quartz window was illuminated using an adjustable-power 365 nm UV lamp to obtain the on / off ratio of the device at different power levels; a Keithley 6487 picoammeter was used, and the bias voltage was controlled and the current versus time curves were recorded via a LabVIEW graphical programming interface. The switching characteristics of the UV photoelectric sensor are as follows: Figure 3 As shown, under a bias voltage of 0.2 V, the maximum power (800 mW / cm) 2 The maximum current switching ratio can be obtained at around 300 (left and right).

[0111] Example 3

[0112] This embodiment provides a study on the effect of the distance between the hydrogels of the first and second electrodes on the on / off ratio.

[0113] Referring to Examples 1 and 2, the distance between the first and second electrodes was varied (from large to small to minimize contamination, and excess portions were removed) to 50, 40, 30, 20, and 10 mm, respectively, with a power consumption of approximately 700 mW / cm. 2 Irradiation with 365 nm ultraviolet light.

[0114] The results are as follows Figure 5 As shown, the measured on / off ratios were 132, 192, 149, 118, and 73, respectively. The distance between the hydrogels of the first and second electrodes is related to the conductivity and temperature rise. The closer the distance, the greater the conductivity at the same voltage; while the farther the distance, the more significant the temperature rise in the central region due to the larger specific heat capacity of the hydrogel. Considering both the promoting effect of reducing the electrode spacing on current and the suppressing effect on the central temperature (due to the larger specific heat capacity of the hydrogel), the appropriate distance to obtain a larger on / off ratio is approximately 40 mm.

[0115] Example 4

[0116] This embodiment provides a study on the effect of substrate thickness on substrate temperature changes.

[0117] Referring to Examples 1 and 2, sensors with different substrate thicknesses were fabricated. The substrate thicknesses were 14.2 μm, 55.8 μm, 82 μm, 114.6 μm, 132.4 μm, and 196.2 μm, respectively, and the power used was approximately 700 mW / cm². 2The substrate was irradiated with a 365 nm ultraviolet lamp. A temperature probe was placed below the substrate, and the temperature changes when the probe was in contact with the substrate and when it was not in contact were compared to determine that the probe temperature originated from the substrate temperature. The temperature change was obtained by subtracting the non-illuminated temperature from the stable temperature when the probe was in contact with the substrate using the temperature data when the probe was in contact with the substrate.

[0118] The results are as follows Figure 6 As shown, the temperatures are 63℃, 73.5℃, 79.7℃, 82.6℃, 89.7℃, and 78℃, respectively. The smaller the thickness, the less light absorption and the smaller the temperature change; conversely, the greater the thickness, the greater the light absorption required to raise the temperature by the same amount. Therefore, the substrate thickness needs to be as thick as possible. However, the applicant's research found that the temperature change decreases when the substrate thickness exceeds 130 μm, so a thickness not exceeding 130 μm is preferred.

[0119] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A surface ion transport based ultraviolet photovoltaic sensor, characterized in that, The application relates to a surface ion transport-based ultraviolet photodetector, which comprises a power supply, a power meter, a substrate, a first electrode and a second electrode, wherein the first electrode and the second electrode each comprise porous hydrophilic material and a non-polar electrode connected with the porous hydrophilic material; the porous hydrophilic material of the first electrode and the second electrode is arranged on the surface of the substrate, and the non-polar electrodes of the first electrode and the second electrode are connected with the power supply and the power meter through an electric circuit. The substrate comprises a wide-bandgap semiconductor with strong hydrophilic characteristics, wherein the strong hydrophilic characteristics refer to that the contact angle of the wide-bandgap semiconductor is less than or equal to 30 degrees, and the wide-bandgap semiconductor refers to a semiconductor with a band gap width greater than or equal to 3.2 eV. The water solution absorbed by the porous hydrophilic material comprises anions and cations. The substrate is selected from any one of muscovite, biotite, vermiculite and kaolinite, and the thickness is 10-200 microns. The porous hydrophilic material is selected from any one or more of artificial hydrogel, natural hydrogel and solid electrolyte; and the distance between the porous hydrophilic materials of the first electrode and the second electrode is 10-50 mm.

2. The surface ion transport based ultraviolet photovoltaic sensor of claim 1, wherein, The non-polar electrode is selected from a silver / silver chloride electrode, a mercury electrode or a copper / copper sulfate electrode.

3. The surface ion transport based ultraviolet photovoltaic sensor of claim 2, wherein, The method comprises the following steps:

4. The surface ion transport based ultraviolet photosensor of claim 3, wherein, S01, preparing a power supply, a power meter, a non-polar electrode, a wide-bandgap semiconductor substrate with strong hydrophilic characteristics, and porous hydrophilic material for absorbing a water solution containing anions and cations; the strong hydrophilic characteristics refer to that the contact angle of the wide-bandgap semiconductor is less than or equal to 30 degrees, and the wide-bandgap semiconductor refers to a semiconductor with a band gap width greater than or equal to 3.2 eV; 5. The surface ion transport based ultraviolet photosensor according to any one of claims 1-4, wherein, The porous hydrophilic material adsorbs an aqueous solution of any one or more of anions selected from Cl - , Br - , I - ; and cations selected from K + , Na + , Li + .

6. A method of fabricating a surface ion transport based ultraviolet photovoltaic sensor, comprising: S02, connecting the non-polar electrode with the porous hydrophilic material to form a first electrode and a second electrode, and placing the electrodes on the surface of the substrate according to the distance; the distance between the porous hydrophilic materials of the first electrode and the second electrode is 10-50 mm; S03, connecting the non-polar electrodes of the first electrode and the second electrode with the power supply and the power meter through an electric circuit to form a surface ion transport-based ultraviolet photodetector. The preparation of the porous hydrophilic material for absorbing the water solution containing anions and cations comprises the following steps: placing the porous hydrophilic material in a water solution containing anions and cations, and sufficiently absorbing water and exchanging ions. The non-polar electrode is selected from a silver / silver chloride electrode; and the preparation method comprises the following steps: performing a redox reaction on a high-purity silver mesh in a potassium chloride solution to prepare a silver / silver chloride electrode.

7. The method of claim 6, wherein the surface ion transport based ultraviolet phototransducer is prepared by the steps of: The application is used for detecting ultraviolet light.

8. The method for fabricating an ultraviolet photoelectric sensor based on surface ion transport according to claim 6 or 7, characterized in that, The detection of ultraviolet light comprises detecting ultraviolet light in a water vapor environment.

9. Use of a surface ion transport based ultraviolet photovoltaic sensor according to any one of claims 1 to 5, characterized in that ​ 10. Use according to claim 9, characterized in that, ​

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