Self-powered photoelectric detector based on MXene electrode and preparation method thereof

Abstract

The application discloses a self-powered photoelectric detector based on an MXene electrode and a preparation method thereof, 1) a semiconductor wafer is cut to a proper size, washed and dried for standby; 2) a two-dimensional material MXene colloidal solution is prepared; 3) the surface of the semiconductor wafer obtained in the step 1) is treated by air plasma to improve the hydrophilicity, and the MXene colloidal solution is coated on the surface of the semiconductor wafer by a spin coating or a pulling and coating method to form a transparent MXene film; 4) the MXene colloidal solution is further coated on one half of the surface of the product obtained in the step 3) by a drop coating or a spray coating method, and is naturally dried at room temperature to form an opaque MXene thick film; and 5) conductive tapes are respectively attached to the edges of the MXene thin film and the thick film of the product obtained in the step 4) as test electrodes. The application adopts a full solution process, is simple in operation, low in cost, and the prepared device has excellent performance.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic device design and fabrication technology, and in particular to a self-powered photodetector based on MXene electrodes and its fabrication method. Background Technology

[0002] With the rapid development of IoT technology, sensor networks, serving as data acquisition terminals for IoT, are becoming increasingly dense and massive. Therefore, to save energy and improve integration, sensors need to possess self-powered capabilities that allow them to operate without an external voltage. Photodetectors, as one of the important sensors in IoT systems, can convert incident light signals into easily detectable and analyzable electrical signals, and have wide applications in defense, military, and civilian fields such as optical guidance, imaging, and medical detection. However, most photodetectors currently in practical use lack self-powered capabilities, limiting their application in IoT and wearable electronic devices.

[0003] Existing self-powered detectors are mainly based on pn junctions or Schottky junctions. The fabrication of pn junctions requires expensive and complex methods such as ion implantation and epitaxial growth, while self-powered detectors based on Schottky junctions typically require vacuum deposition of two different metal thin films on the semiconductor surface, making the fabrication process equally complex and cumbersome. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention aims to provide a self-powered photodetector based on MXene electrodes and its fabrication method. The photodetector has self-powered capability, and its fabrication adopts an all-solution process, which is simple to operate, low in cost, and the fabricated device has excellent performance.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A self-powered photodetector based on MXene electrodes uses a semiconductor wafer as the photosensitive layer, and coats a transparent MXene thin film and an opaque MXene thick film on different regions of its surface (any crystal plane).

[0007] The different regions refer to a transparent MXene film coated on one half of the wafer and an opaque MXene thick film coated on the other half, with the two films connected together.

[0008] The semiconductor wafer material is a common semiconductor such as silicon, gallium arsenide, silicon carbide, or gallium nitride.

[0009] The MXene film has a thickness of 5-10 nm.

[0010] The MXene thick film has a thickness of 95-100 nm.

[0011] The MXene is a single-layer or few-layer (two or more layers) two-dimensional material.

[0012] A method for fabricating a self-powered photodetector based on MXene electrodes includes the following steps;

[0013] 1) Cut the semiconductor wafer to the appropriate size, clean it, and let it air dry for later use;

[0014] 2) Preparation of MXene colloidal solution, a two-dimensional material;

[0015] 3) The surface of the semiconductor wafer obtained in step 1) is treated with air plasma to improve its hydrophilicity, and an MXene colloidal solution is coated on the surface of the semiconductor wafer by spin coating or dip coating to form a transparent MXene film.

[0016] 4) Continue to apply MXene colloidal solution to half of the surface area of ​​the product obtained in step 3) using the method of drop coating or spray coating, and let it air dry naturally at room temperature to form an opaque MXene thick film;

[0017] 5) Apply conductive tape to the edges of the MXene thin film and thick film of the product obtained in step 4) as test electrodes.

[0018] The specific operation of step 1) is as follows: cut the semiconductor wafer to a suitable size using a glass cutter, and then ultrasonically clean it with acetone, ethanol and deionized water in sequence, and air dry it in a dust-free environment.

[0019] The specific operation of step 2) is as follows: 1-3g of LiF powder is added to a polytetrafluoroethylene beaker containing 15-30mL of concentrated hydrochloric acid. After stirring for 10min, 1-2g of Ti3AlC2 powder is added. The beaker is then sealed and etched in an oil bath at 40℃ for 24-48h. After etching, the obtained product is centrifuged and washed with deionized water until the pH of the supernatant is ≥6. A certain amount of deionized water is added to the precipitate obtained by centrifugation, and the mixture is placed in an ice bath and sonicated for 1-2h. After sonication, the mixture is centrifuged at 3500 rpm for 1h. The obtained supernatant is the two-dimensional material MXene colloidal solution with a concentration of 3-6mg / mL.

[0020] The specific operation of step 3) is as follows: the semiconductor wafer is placed in a plasma cleaner and treated with air plasma at a power of 10-80W for 1-30 minutes to improve the surface hydrophilicity. Then, a transparent MXene film is coated on the surface of the semiconductor wafer by spin coating or dip coating. Taking spin coating as an example, the wafer is adsorbed on a spin coater and MXene colloidal solution is dropped onto its surface. The spin coating speed is 2000-4000 rpm and the spin coating time is 10-20s. After spin coating, the wafer is dried in a nitrogen glove box at 100-150℃ for 10 minutes to make the MXene film completely adhere to the semiconductor wafer.

[0021] The specific operation of step 4) is as follows: MXene dispersion is applied to half of the surface area of ​​the product obtained in step 3) (by means of drop coating or spraying, etc.), and after natural drying, the coating is repeated once to form an opaque MXene thick film on half of the wafer surface.

[0022] The beneficial effects of this invention are:

[0023] 1. This invention proposes a novel method for fabricating a self-powered detector. Compared with existing methods for fabricating self-powered detectors using pn junctions or Schottky junctions, this detector fabrication method does not require expensive equipment or complex processes, employs an all-solution process, and is simple to operate and low in cost.

[0024] 2. This method is versatile and works well with different semiconductor materials. It can be used to prepare photodetectors sensitive to different wavelengths of light as needed.

[0025] 3. The detectors prepared by this method have excellent performance, such as high responsivity, fast response speed and good stability, and have better performance than devices prepared by traditional methods such as ion implantation and vacuum deposition. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a self-powered photodetector prepared by the method proposed in this invention.

[0027] Figure 2 The responsivity of MXene / silicon, MXene / gallium arsenide, MXene / silicon carbide, and MXene / gallium nitride self-powered photodetectors prepared using the method proposed in this invention to different wavelengths of light without an applied voltage. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings.

[0029] Example 1:

[0030] (1) Cut the single crystal silicon wafer to 1.5×2cm using a glass cutter, and clean it with acetone, ethanol and deionized water in sequence by ultrasonic cleaning, and then dry it in a dust-free environment for later use.

[0031] (2) Synthesis of MXene colloidal solution for two-dimensional material. The specific procedure was as follows: 2g of LiF powder was added to a polytetrafluoroethylene beaker containing 20mL of concentrated hydrochloric acid. After stirring for 10min, 1g of Ti3AlC2 powder was added. The beaker was then sealed and etched in an oil bath at 40℃ for 24h. After etching, the resulting product was washed with deionized water by centrifugation until the pH of the supernatant was ≥6. A certain amount of deionized water was added to the precipitate obtained by centrifugation, and the mixture was placed in an ice bath and sonicated for 1h. After sonication, the mixture was centrifuged at 3500 rpm for 1h. The resulting supernatant was the MXene colloidal solution for two-dimensional material, with a concentration of 3mg / mL.

[0032] (3) The ultrasonically cleaned single-crystal silicon wafer was placed in a plasma cleaner and surface treated with 10W air plasma for 30 minutes to improve hydrophilicity. Then, a layer of MXene colloidal dispersion was spin-coated onto its surface to form a transparent MXene film. The spin-coating speed was 3000 rpm and the spin-coating time was 10 seconds. After spin-coating, the wafer was dried in a nitrogen glove box at 120°C for 10 minutes to ensure complete adhesion between the MXene film and the single-crystal silicon wafer.

[0033] (4) A layer of MXene colloidal solution is drop-coated onto half of the MXene transparent film obtained in (3). After natural drying, this operation is repeated to form an opaque MXene thick film on half of the silicon wafer surface. (e.g.) Figure 1 (As shown)

[0034] (5) Copper tape is attached to the edges of the MXene thin film and thick film of the device obtained in step (4) as test electrodes.

[0035] Example 2:

[0036] (1) Cut the gallium arsenide single crystal wafer to 1.5×2cm using a glass cutter, and clean it with acetone, ethanol and deionized water in sequence by ultrasonic cleaning, and then dry it in a dust-free environment for later use.

[0037] (2) Synthesis of MXene colloidal solution for two-dimensional material. The specific procedure was as follows: 1.5g LiF powder was added to a polytetrafluoroethylene beaker containing 25mL concentrated hydrochloric acid. After stirring for 10min, 2g Ti3AlC2 powder was added. The beaker was then sealed and etched in an oil bath at 40℃ for 48h. After etching, the resulting product was washed with deionized water by centrifugation until the supernatant pH ≥ 6. A certain amount of deionized water was added to the precipitate obtained by centrifugation, and the mixture was placed in an ice bath and sonicated for 2h. After sonication, the mixture was centrifuged at 3500 rpm for 1h. The resulting supernatant was the MXene colloidal solution for two-dimensional material, with a concentration of 6mg / mL.

[0038] (3) The ultrasonically cleaned gallium arsenide single crystal wafer was placed in a plasma cleaner and surface treated with 20W air plasma for 8 minutes to improve hydrophilicity. Then, a layer of MXene colloidal dispersion was spin-coated onto its surface to form a transparent MXene film. The spin-coating speed was 2000 rpm and the spin-coating time was 20 seconds. After spin-coating, the wafer was dried in a nitrogen glove box at 150°C for 10 minutes to ensure complete adhesion between the MXene film and the gallium arsenide wafer.

[0039] (4) A layer of MXene colloidal solution is drop-coated onto half of the MXene transparent film obtained in (3). After natural drying, the operation is repeated to form an opaque MXene thick film on half of the gallium arsenide wafer surface.

[0040] (5) Copper tape is attached to the edges of the MXene thin film and thick film of the device obtained in step (4) as test electrodes.

[0041] Example 3:

[0042] (1) Cut the silicon carbide single crystal wafer to 1.5×2cm using a glass cutter, and clean it with acetone, ethanol and deionized water in sequence by ultrasonic cleaning, and then dry it in a dust-free environment for later use.

[0043] (2) Synthesis of MXene colloidal solution for two-dimensional material. The specific procedure was as follows: 1.5 g of LiF powder was added to a polytetrafluoroethylene beaker containing 25 mL of concentrated hydrochloric acid. After stirring for 10 min, 1.5 g of Ti3AlC2 powder was added. The beaker was then sealed and etched in an oil bath at 40 °C for 32 h. After etching, the resulting product was washed with deionized water by centrifugation until the pH of the supernatant was ≥ 6. A certain amount of deionized water was added to the precipitate obtained by centrifugation, and the mixture was sonicated in an ice bath for 1.5 h. After sonication, the mixture was centrifuged at 3500 rpm for 1 h. The resulting supernatant was the MXene colloidal solution for two-dimensional material, with a concentration of 4.5 mg / mL.

[0044] (3) The ultrasonically cleaned silicon carbide single crystal wafer was placed in a plasma cleaner and surface treated with 80W air plasma for 1 minute to improve hydrophilicity. Then, a layer of MXene colloidal dispersion was spin-coated onto its surface to form a transparent MXene film. The spin-coating speed was 2000 rpm and the spin-coating time was 20 seconds. After spin-coating, the wafer was dried in a nitrogen glove box at 120°C for 10 minutes to ensure complete adhesion between the MXene film and the silicon carbide wafer.

[0045] (4) A layer of MXene colloidal solution is drop-coated onto half of the MXene transparent film obtained in (3). After natural drying, the operation is repeated to form an opaque MXene thick film on half of the silicon carbide wafer surface.

[0046] (5) The conductive tape is attached to the edges of the MXene thin film and thick film of the device obtained in step (4) as test electrodes.

[0047] Example 4:

[0048] (1) Cut the gallium nitride thick film single crystal wafer with sapphire as substrate to 1.5×2cm size with a glass cutter, and clean it with acetone, ethanol and deionized water in sequence by ultrasonic cleaning, and then dry it in a dust-free environment for later use.

[0049] (2) Synthesis of MXene colloidal solution for two-dimensional material. The specific procedure was as follows: 2g of LiF powder was added to a polytetrafluoroethylene beaker containing 30mL of concentrated hydrochloric acid. After stirring for 10min, 1.5g of Ti3AlC2 powder was added. The beaker was then sealed and etched in an oil bath at 40℃ for 24h. After etching, the resulting product was washed with deionized water by centrifugation until the pH of the supernatant was ≥6. A certain amount of deionized water was added to the precipitate obtained by centrifugation, and the mixture was placed in an ice bath and sonicated for 1h. After sonication, the mixture was centrifuged at 3500 rpm for 1h. The resulting supernatant was the MXene colloidal solution for two-dimensional material, with a concentration of 4.5mg / mL.

[0050] (3) The ultrasonically cleaned gallium nitride thick film single crystal wafer was placed in a plasma cleaner and surface treated with 30W air plasma for 3 minutes to improve hydrophilicity. Then, a layer of MXene colloidal dispersion was spin-coated onto its surface to form a transparent MXene film. The spin-coating speed was 4000 rpm and the spin-coating time was 10 seconds. After spin-coating, the wafer was dried in a nitrogen glove box at 120°C for 10 minutes to ensure complete adhesion between the MXene film and the gallium nitride wafer.

[0051] (4) A layer of MXene colloidal solution is drop-coated onto half of the MXene transparent film obtained in (3). After natural drying, the operation is repeated to form an opaque MXene thick film on half of the silicon wafer surface.

[0052] (5) Copper tape is attached to the edges of the MXene thin film and thick film of the device obtained in step (4) as test electrodes.

[0053] Figure 2 The responsivity of the self-powered detectors prepared in the different embodiments described above is shown. It can be seen that the prepared MXene / silicon, MXene / gallium arsenide, MXene / silicon carbide and MXene / gallium nitride photodetectors all have high responsivity at 0V, which proves the versatility of the method and the excellent performance of the prepared devices.

Claims

1. A self-powered photodetector based on MXene electrode, characterized in that, A semiconductor wafer is used as a photosensitive layer, and transparent MXene thin films and opaque MXene thick films are coated on different regions of the surface of the semiconductor wafer; The different regions refer to that a transparent MXene thin film is coated on one half region of the wafer, and an opaque MXene thick film is coated on the other half region, and the two films are connected; The MXene thin film has a thickness of 5-10 nm; The MXene thick film has a thickness of 95-100 nm.

2. The self-powered photodetector based on MXene electrode according to claim 1, wherein, The semiconductor wafer material is silicon, gallium arsenide, silicon carbide or gallium nitride.

3. The self-powered photodetector based on MXene electrode according to claim 1, wherein, The MXene is a single-layer or few-layer two-dimensional material.

4. The method of claim 1-3, wherein, The method comprises the following steps: 1) cutting a semiconductor wafer to a suitable size, cleaning and drying for standby; 2) preparing a two-dimensional material MXene colloidal solution; 3) treating the surface of the semiconductor wafer obtained in step 1) by air plasma to improve its hydrophilicity, and coating the MXene colloidal solution on the surface of the semiconductor wafer by spin coating or pulling film coating to form a transparent MXene thin film; 4) continuing to coat the MXene colloidal solution on one half region of the surface of the product obtained in step 3) by drop coating or spraying, and naturally drying at room temperature to form an opaque MXene thick film; 5) respectively pasting conductive adhesive tapes on the edges of the MXene thin film and thick film of the product obtained in step 4) as test electrodes.

5. The method of claim 4, wherein the MXene electrode-based self-powered photodetector is prepared by the steps of: The specific operation of step 1) is that the semiconductor wafer is cut to a suitable size by a glass cutter, and is sequentially ultrasonically cleaned with acetone, ethanol and deionized water, and is dried in a dust-free environment.

6. The method of claim 5, wherein the MXene electrode-based self-powered photodetector is prepared by the steps of: The specific operation of step 2) is that 1-3 g of LiF powder is added into a polytetrafluoroethylene beaker containing 15-30 mL of concentrated hydrochloric acid, 1-2 g of Ti3AlC2 powder is added after stirring for 10 min, the beaker is sealed and stirred in a 40℃ oil bath for 24-48 h for etching, and after the etching is completed, the obtained product is centrifuged with deionized water until the supernatant PH is greater than or equal to 6, a certain amount of deionized water is added into the obtained sediment, and the mixture is placed in an ice bath for ultrasonic treatment for 1-2 h, and then centrifuged at 3500 r / min for 1 h, and the obtained supernatant is the two-dimensional material MXene colloidal solution, and the concentration of the colloidal solution is 3-6 mg / mL.

7. The method of claim 4, wherein the MXene electrode-based self-powered photodetector is prepared by the steps of: The specific operation of step 3) is that the semiconductor wafer is placed into a plasma cleaning machine, and the surface is treated by air plasma at a power of 10-80 W for 1-30 min to improve the hydrophilicity, and then a transparent MXene thin film is coated on the surface of the semiconductor wafer by spin coating or pulling film coating; when spin coating is adopted, the wafer is adsorbed on a spin coater, MXene colloidal solution is added dropwise on the surface, the spin coating speed is 2000-4000 r / min, the spin coating time is 10-20 s, and after the spin coating is completed, the wafer is heated at 100-150℃ for 10 min in a nitrogen glove box for drying, so that the MXene thin film is completely attached to the semiconductor wafer.

8. The method of claim 4, wherein the method further comprises: The specific operation of the step 4) is that the surface of the other half of the region of the product obtained in the step 3) is coated with the MXene dispersion liquid, and after natural air drying, the coating is repeated once, so that the other half of the region of the wafer surface forms an opaque MXene thick film.

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