Composite structure infrared photoelectric detector and preparation method thereof
By adopting composite structures in infrared photodetectors, including N-type silicon substrates, graphene, vanadium dioxide and titanium dioxide films, combined with vacuum packaging technology, the problem of easy destruction of traditional detectors in strong light environments is solved, and detection is improved The durability and adaptability of the device achieve stable operation in special environments.
Patent Information
- Application Number
- CN202411301466.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-18
- Publication Date
- 2024-12-27
AI Technical Summary
Traditional infrared photodetectors are prone to sunburn in the environment of strong sunlight, resulting in some pixels being destroyed and unable to work properly, which has brought many restrictions to the application of detectors in special environments.
Using composite structure infrared photodetectors, including N-type silicon substrates, graphene films, vanadium dioxide films and titanium dioxide films, they are grown and coated on the silicon substrate through microwave plasma chemical vapor deposition and magnetron sputtering coating processes, combined with vacuum packaging Technically create optical windows to form high-performance infrared photodetectors.
The light absorption capacity and response speed of infrared photodetectors are improved, the durability and adaptability of the detectors are enhanced, the problem of sunburn phenomenon is overcome, and stable work in special environments is achieved.
Smart Images
Figure CN119208427A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of infrared photoelectric detector application technology, and in particular to a composite structure infrared photoelectric detector and a preparation method thereof. Background Art
[0002] An infrared photoelectric detector is a device that uses infrared radiation for imaging. It has the advantages of long operating range, good anti-interference, and strong ability to penetrate smoke and haze. It plays an important role in military, communications, remote sensing, life sciences and other fields. Infrared photoelectric detectors receive infrared radiation reflected or spontaneously emitted by the target and convert it into electrical signals, thereby achieving detection and imaging of the target.
[0003] Infrared thermal imaging detection application technology plays an important role in the fields of electricity, navigation, autonomous driving, medical health, etc. In the field of uncooled infrared detection, traditional infrared detectors have already possessed good detection and imaging functions and have been widely used. However, the material properties used to make the detectors determine that the detectors are prone to sunburn when facing strong sunlight, causing some pixels to be destroyed and unable to work normally, which brings many limitations to the application of detectors in special environments. Therefore, the present invention proposes a composite structure infrared photoelectric detector and a preparation method thereof. Summary of the invention
[0004] The technical problem to be solved by the present invention is to provide a composite structure infrared photoelectric detector and a preparation method thereof, so as to solve the problem that traditional detectors are prone to sunburn, resulting in partial pixel damage and inability to work normally, which brings many restrictions to the application of detectors in special environments.
[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: On the one hand, a composite structure infrared photodetector is provided, comprising an N-type silicon substrate, a readout circuit is arranged at the bottom of the N-type silicon substrate, a graphene film is arranged on the top of the N-type silicon substrate, a vanadium dioxide film is evaporated on the top of the graphene film, a titanium dioxide film is sputtered on the top surface of the vanadium dioxide film, a silicon nitride film is sputtered on the top surface of the titanium dioxide film, and an optical window is made on the top of the silicon oxide film by using packaging technology; Among them, an optical microcavity is arranged on the top of the N-type silicon substrate, the thickness of the optical microcavity coincides with the working area of the graphene film, the vanadium dioxide film and the titanium dioxide film, and for infrared light of the same wavelength, the thickness of the optical microcavity is equal to the optical path of the wavelength or differs by an integer multiple of half a wavelength.
[0006] On the other hand, a method for preparing a composite structure infrared photoelectric detector is provided: The first preparation method comprises the following steps: S1. Cut the N-type silicon substrate with a thickness of 500 μm and containing the readout circuit and optical microcavity into 0.5×1 cm 2 size, and ultrasonically treated with acetone and alcohol for 10 minutes, then ultrasonically treated with deionized water for 5 minutes, and then dried with a nitrogen gun to obtain an N-type silicon substrate; S2, using microwave plasma chemical vapor deposition technology to grow a graphene film inside the optical microcavity on the top of the N-type silicon substrate, with a thickness of 20-100nm; S3, using magnetron sputtering coating technology, with VO2 target with purity of 99.99% as material, in a vacuum higher than 3×10 -5 Under the condition of 1.5 Pa, a 50-100 nm vanadium dioxide film is evaporated on the upper surface of the graphene film; S4, sputtering a 50-100 nm titanium dioxide film layer on the surface of the vanadium dioxide film layer; and simultaneously sputtering a 50-100 nm silicon nitride film on the titanium dioxide film layer; S5. Use vacuum packaging technology to complete the sealing connection between the optical window and the graphene film, vanadium dioxide film and titanium dioxide film to complete the production of the detector.
[0007] The second preparation method comprises the following steps: S1. Cut the N-type silicon substrate with a thickness of 500 μm and containing the readout circuit and optical microcavity into 0.5×1 cm 2 size, and ultrasonically treated with acetone and alcohol for 10 minutes, then ultrasonically treated with deionized water for 5 minutes, and then dried with a nitrogen gun to obtain an N-type silicon substrate; S2, using microwave plasma chemical vapor deposition technology to grow a graphene film inside the optical microcavity on the top of the N-type silicon substrate with a thickness of 80nm; S3, using magnetron sputtering coating technology, with VO2 target with purity of 99.99% as material, in a vacuum higher than 3×10 -5 Under the condition of 1.5 Pa, a 50-100 nm vanadium dioxide film is evaporated on the upper surface of the graphene film; S4, sputtering a 50-100 nm titanium dioxide film layer on the surface of the vanadium dioxide film layer; and simultaneously sputtering a 50-100 nm silicon nitride film on the titanium dioxide film layer; S5. Use vacuum packaging technology to complete the sealing connection between the optical window and the graphene film, vanadium dioxide film and titanium dioxide film to complete the production of the detector.
[0008] The third preparation method comprises the following steps: S1. Cut the N-type silicon substrate with a thickness of 500 μm and containing the readout circuit and optical microcavity into 0.5×1 cm 2size, and ultrasonically treated with acetone and alcohol for 10 minutes, then ultrasonically treated with deionized water for 5 minutes, and then dried with a nitrogen gun to obtain an N-type silicon substrate; S2, using microwave plasma chemical vapor deposition technology to grow a graphene film inside the optical microcavity on the top of the N-type silicon substrate, with a thickness of 20-100nm; S3, using magnetron sputtering coating technology, with VO2 target with purity of 99.99% as material, in a vacuum higher than 3×10 -5 Under the condition of 1.5 Pa, a 50-100 nm vanadium dioxide film is evaporated on the upper surface of the graphene film; S4, sputtering a 50-100 nm titanium dioxide film layer on the surface of the vanadium dioxide film layer; and simultaneously sputtering a 100 nm silicon nitride film on the titanium dioxide film layer; S5. Use vacuum packaging technology to complete the sealing connection between the optical window and the graphene film, vanadium dioxide film and titanium dioxide film to complete the production of the detector.
[0009] The fourth preparation method comprises the following steps: S1. Cut the N-type silicon substrate with a thickness of 500 μm and containing the readout circuit and optical microcavity into 0.5×1 cm 2 size, and ultrasonically treated with acetone and alcohol for 10 minutes, then ultrasonically treated with deionized water for 5 minutes, and then dried with a nitrogen gun to obtain an N-type silicon substrate; S2, using microwave plasma chemical vapor deposition technology to grow a graphene film inside the optical microcavity on the top of the N-type silicon substrate, with a thickness of 20-100nm; S3, using magnetron sputtering coating technology, with VO2 target with purity of 99.99% as material, in a vacuum higher than 3×10 -5 Under the condition of 1.5 Pa, a 50-100 nm vanadium dioxide film is evaporated on the upper surface of the graphene film; S4, sputtering a 50-100 nm titanium dioxide film layer on the surface of the vanadium dioxide film layer; and simultaneously sputtering a 150 nm silicon nitride film on the titanium dioxide film layer; S5. Use vacuum packaging technology to complete the sealing connection between the optical window and the graphene film, vanadium dioxide film and titanium dioxide film to complete the production of the detector.
[0010] The fifth preparation method comprises the following steps: S1. Cut the N-type silicon substrate with a thickness of 500 μm and containing the readout circuit and optical microcavity into 0.5×1 cm 2 size, and ultrasonically treated with acetone and alcohol for 10 minutes, then ultrasonically treated with deionized water for 5 minutes, and then dried with a nitrogen gun to obtain an N-type silicon substrate; S2, using microwave plasma chemical vapor deposition technology to grow a graphene film inside the optical microcavity on the top of the N-type silicon substrate, with a thickness of 20-100nm; S3, using magnetron sputtering coating technology, with VO2 target with purity of 99.99% as material, in a vacuum higher than 3×10 -5 Pa, a 100nm thick vanadium dioxide film was evaporated on the upper surface of the graphene film; S4, sputtering a 50-100 nm titanium dioxide film layer on the surface of the vanadium dioxide film layer; and simultaneously sputtering a 50-100 nm silicon nitride film on the titanium dioxide film layer; S5. Use vacuum packaging technology to complete the sealing connection between the optical window and the graphene film, vanadium dioxide film and titanium dioxide film to complete the production of the detector.
[0011] The beneficial effects of the present invention are as follows: 1. The present invention prepares a titanium dioxide / graphene / vanadium dioxide array infrared photodetector by a simple process method, which not only utilizes the sensitivity of graphene to infrared light and the high phase transition temperature and TCR characteristics of titanium dioxide nanoparticles, but also combines the excellent properties of graphene such as high conductivity, low resistivity, and high transmittance to prepare a high-performance infrared photodetector; 2. The present invention adopts the CVD method to in-situ grow a layer of graphene film on the surface of the silicon substrate as a photosensitive absorption layer, while improving the bonding force of the titanium dioxide array film; 3. The present invention utilizes a magnetron sputtering coating process to evaporate a titanium dioxide layer on the upper surface of a graphene substrate, and the upper surface of the prepared titanium dioxide array is flat, so that the laid graphene is in close contact with the titanium dioxide array, thereby achieving good physical contact between the graphene and the titanium dioxide film, and the resulting infrared detector has a strong light absorption capability and a fast response speed.
[0012] 4. The present invention utilizes a plasma implantation method to adjust oxygen vacancies in a silicon-based composite film, and the prepared titanium dioxide / graphene film has a smooth surface and good contact, thereby improving the electrical conductivity of the titanium dioxide / graphene / vanadium dioxide film, thereby improving the thermal conductivity of the film. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 The cross-sectional structure diagram of a composite structure infrared photoelectric detector and a preparation method thereof according to the present invention.
[0014] In the figure: 1. Readout circuit; 2. N-type silicon substrate; 3. Graphene film; 4. Vanadium dioxide film; 5. Titanium dioxide film; 6. Silicon nitride film. DETAILED DESCRIPTION
[0015] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.
[0016] like Figure 1 A composite structure infrared photodetector is shown, comprising an N-type silicon substrate 2, a readout circuit 1 is arranged at the bottom of the N-type silicon substrate 2, a graphene film 3 is arranged on the top of the N-type silicon substrate 2, a vanadium dioxide film 4 is evaporated on the top of the graphene film 3, a titanium dioxide film 5 is sputtered on the top surface of the vanadium dioxide film 4, a silicon nitride film 6 is sputtered on the top surface of the titanium dioxide film 5, and an optical window is made on the top of the silicon oxide film 6 by adopting packaging technology; Among them, an optical microcavity is arranged on the top of the N-type silicon substrate 2, and the thickness of the optical microcavity coincides with the working area of the graphene film 3, the vanadium dioxide film 4 and the titanium dioxide film 5, and for infrared light of the same wavelength, the thickness of the optical microcavity is equal to the optical path of the wavelength or differs by an integer multiple of half a wavelength.
[0017] Embodiment 1: like Figure 1 As shown, a method for preparing a composite structure infrared photoelectric detector comprises the following steps: S1. Cut the N-type silicon substrate with a thickness of 500 μm and containing the readout circuit 1 and the optical microcavity into 0.5×1 cm 2 size, sequentially ultrasonically treated with acetone and alcohol for 10 minutes, then ultrasonically treated with deionized water for 5 minutes, and then dried with a nitrogen gun to obtain an N-type silicon substrate 2; S2, using microwave plasma chemical vapor deposition technology to grow a graphene film 3 inside the optical microcavity on the top of the N-type silicon substrate 2, with a thickness of 20-100 nm; S3, using magnetron sputtering coating technology, with VO2 target with purity of 99.99% as material, in a vacuum higher than 3×10 -5 Pa, a vanadium dioxide film 4 with a thickness of 50-100 nm is evaporated on the upper surface of the graphene film 3; S4, sputtering 5 layers of titanium dioxide film with a thickness of 50-100 nm on the surface of the 4 layers of vanadium dioxide film; and simultaneously sputtering 6 layers of silicon nitride film with a thickness of 50-100 nm on the 5 layers of titanium dioxide film; S5. Using vacuum packaging technology, the optical window is sealed and connected with the graphene film 3, the vanadium dioxide film 4 and the titanium dioxide film 5 to complete the production of the detector.
[0018] Embodiment 2: like Figure 1 As shown, a method for preparing a composite structure infrared photoelectric detector comprises the following steps: S1. Cut the N-type silicon substrate with a thickness of 500 μm and containing the readout circuit 1 and the optical microcavity into 0.5×1 cm 2 size, sequentially ultrasonically treated with acetone and alcohol for 10 minutes, then ultrasonically treated with deionized water for 5 minutes, and then dried with a nitrogen gun to obtain an N-type silicon substrate 2; S2, using microwave plasma chemical vapor deposition technology to grow a graphene film 3 inside the optical microcavity on the top of the N-type silicon substrate 2, with a thickness of 80nm; S3, using magnetron sputtering coating technology, with VO2 target with purity of 99.99% as material, in a vacuum higher than 3×10 -5 Pa, a vanadium dioxide film 4 with a thickness of 50-100 nm is evaporated on the upper surface of the graphene film 3; S4, sputtering 5 layers of titanium dioxide film with a thickness of 50-100 nm on the surface of the 4 layers of vanadium dioxide film; and simultaneously sputtering 6 layers of silicon nitride film with a thickness of 50-100 nm on the 5 layers of titanium dioxide film; S5. Using vacuum packaging technology, the optical window is sealed and connected with the graphene film 3, the vanadium dioxide film 4 and the titanium dioxide film 5 to complete the production of the detector.
[0019] Embodiment three: like Figure 1 As shown, a method for preparing a composite structure infrared photoelectric detector comprises the following steps: S1. Cut the N-type silicon substrate with a thickness of 500 μm and containing the readout circuit 1 and the optical microcavity into 0.5×1 cm 2 size, sequentially ultrasonically treated with acetone and alcohol for 10 minutes, then ultrasonically treated with deionized water for 5 minutes, and then dried with a nitrogen gun to obtain an N-type silicon substrate 2; S2, using microwave plasma chemical vapor deposition technology to grow a graphene film 3 inside the optical microcavity on the top of the N-type silicon substrate 2, with a thickness of 20-100 nm; S3, using magnetron sputtering coating technology, with VO2 target with purity of 99.99% as material, in a vacuum higher than 3×10 -5 Pa, a vanadium dioxide film 4 with a thickness of 50-100 nm is evaporated on the upper surface of the graphene film 3; S4, sputtering 5 layers of titanium dioxide film with a thickness of 50-100 nm on the surface of the 4 layers of vanadium dioxide film; and simultaneously sputtering 100 nm of silicon nitride film 6 on the 5 layers of titanium dioxide film; S5. Using vacuum packaging technology, the optical window is sealed and connected with the graphene film 3, the vanadium dioxide film 4 and the titanium dioxide film 5 to complete the production of the detector.
[0020] Embodiment 4: like Figure 1As shown, a method for preparing a composite structure infrared photoelectric detector comprises the following steps: S1. Cut the N-type silicon substrate with a thickness of 500 μm and containing the readout circuit 1 and the optical microcavity into 0.5×1 cm 2 size, sequentially ultrasonically treated with acetone and alcohol for 10 minutes, then ultrasonically treated with deionized water for 5 minutes, and then dried with a nitrogen gun to obtain an N-type silicon substrate 2; S2, using microwave plasma chemical vapor deposition technology to grow a graphene film 3 inside the optical microcavity on the top of the N-type silicon substrate 2, with a thickness of 20-100 nm; S3, using magnetron sputtering coating technology, with VO2 target with purity of 99.99% as material, in a vacuum higher than 3×10 -5 Pa, a vanadium dioxide film 4 with a thickness of 50-100 nm is evaporated on the upper surface of the graphene film 3; S4, sputtering 5 layers of titanium dioxide film with a thickness of 50-100 nm on the surface of the 4 layers of vanadium dioxide film; and at the same time sputtering 150 nm of silicon nitride film 6 on the 5 layers of titanium dioxide film; S5. Using vacuum packaging technology, the optical window is sealed and connected with the graphene film 3, the vanadium dioxide film 4 and the titanium dioxide film 5 to complete the production of the detector.
[0021] Embodiment five: like Figure 1 As shown, a method for preparing a composite structure infrared photoelectric detector comprises the following steps: S1. Cut the N-type silicon substrate with a thickness of 500 μm and containing the readout circuit 1 and the optical microcavity into 0.5×1 cm 2 size, sequentially ultrasonically treated with acetone and alcohol for 10 minutes, then ultrasonically treated with deionized water for 5 minutes, and then dried with a nitrogen gun to obtain an N-type silicon substrate 2; S2, using microwave plasma chemical vapor deposition technology to grow a graphene film 3 inside the optical microcavity on the top of the N-type silicon substrate 2, with a thickness of 20-100 nm; S3, using magnetron sputtering coating technology, with VO2 target with purity of 99.99% as material, in a vacuum higher than 3×10 -5 Pa, a 100 nm thick vanadium dioxide film 4 is evaporated on the upper surface of the graphene film 3; S4, sputtering 5 layers of titanium dioxide film with a thickness of 50-100 nm on the surface of the 4 layers of vanadium dioxide film; and simultaneously sputtering 6 layers of silicon nitride film with a thickness of 50-100 nm on the 5 layers of titanium dioxide film; S5. Using vacuum packaging technology, the optical window is sealed and connected with the graphene film 3, the vanadium dioxide film 4 and the titanium dioxide film 5 to complete the production of the detector.
[0022] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.
Claims
1. A composite structure infrared photoelectric detector, comprising an N-type silicon substrate (2), characterized in that: A readout circuit (1) is arranged at the bottom of the N-type silicon substrate (2), a graphene film (3) is arranged at the top of the N-type silicon substrate (2), a vanadium dioxide film (4) is evaporated on the top of the graphene film (3), a titanium dioxide film (5) is sputtered on the top surface of the vanadium dioxide film (4), a silicon nitride film (6) is sputtered on the top surface of the titanium dioxide film (5), and an optical window is manufactured on the top of the silicon oxide film (6) using packaging technology; An optical microcavity is arranged on the top of the N-type silicon substrate (2), the thickness of the optical microcavity coincides with the working areas of the graphene film (3), the vanadium dioxide film (4) and the titanium dioxide film (5), and for infrared light of the same wavelength, the thickness of the optical microcavity is equal to the optical path length of the wavelength or differs by an integral multiple of half a wavelength.
2. A method for preparing a composite structure infrared photoelectric detector according to claim 1, characterized in that: The steps include: S1. Cut the N-type silicon substrate with a thickness of 500 μm and containing the readout circuit (1) and the optical microcavity into 0.5×1 cm 2 size, ultrasonically treated with acetone and alcohol for 10 minutes, then ultrasonically treated with deionized water for 5 minutes, and then dried with a nitrogen gun to obtain an N-type silicon substrate (2); S2, using microwave plasma chemical vapor deposition technology to grow a graphene film (3) inside the optical microcavity on the top of the N-type silicon substrate (2), with a thickness of 20-100 nm; S3, using magnetron sputtering coating technology, with VO2 target with purity of 99.99% as material, in a vacuum higher than 3×10 -5 Under the condition of 1.50 Pa, a vanadium dioxide film (4) with a thickness of 50-100 nm is evaporated on the upper surface of the graphene film (3); S4, sputtering a 50-100 nm layer of titanium dioxide film (5) on the surface of the vanadium dioxide film (4); and simultaneously sputtering a 50-100 nm layer of silicon nitride film (6) on the titanium dioxide film (5); S5. Using vacuum packaging technology, the optical window is sealed and connected with the graphene film (3), the vanadium dioxide film (4) and the titanium dioxide film (5), thereby completing the production of the detector.
3. A method for preparing a composite structure infrared photoelectric detector according to claim 1, characterized in that: The steps include: S1. Cut the N-type silicon substrate with a thickness of 500 μm and containing the readout circuit (1) and the optical microcavity into 0.5×1 cm 2 size, ultrasonically treated with acetone and alcohol for 10 minutes, then ultrasonically treated with deionized water for 5 minutes, and then dried with a nitrogen gun to obtain an N-type silicon substrate (2); S2, using microwave plasma chemical vapor deposition technology to grow a graphene film (3) with a thickness of 80 nm inside the optical microcavity on the top of the N-type silicon substrate (2); S3, using magnetron sputtering coating technology, with VO2 target with purity of 99.99% as material, in a vacuum higher than 3×10 -5 Under the condition of 1.50 Pa, a vanadium dioxide film (4) with a thickness of 50-100 nm is evaporated on the upper surface of the graphene film (3); S4, sputtering a 50-100 nm layer of titanium dioxide film (5) on the surface of the vanadium dioxide film (4); and simultaneously sputtering a 50-100 nm layer of silicon nitride film (6) on the titanium dioxide film (5); S5. Using vacuum packaging technology, the optical window is sealed and connected with the graphene film (3), the vanadium dioxide film (4) and the titanium dioxide film (5), thereby completing the production of the detector.
4. A method for preparing a composite structure infrared photoelectric detector according to claim 1, characterized in that: The steps include: S1. Cut the N-type silicon substrate with a thickness of 500 μm and containing the readout circuit (1) and the optical microcavity into 0.5×1 cm 2 size, ultrasonically treated with acetone and alcohol for 10 minutes, then ultrasonically treated with deionized water for 5 minutes, and then dried with a nitrogen gun to obtain an N-type silicon substrate (2); S2, using microwave plasma chemical vapor deposition technology to grow a graphene film (3) inside the optical microcavity on the top of the N-type silicon substrate (2), with a thickness of 20-100 nm; S3, using magnetron sputtering coating technology, with VO2 target with purity of 99.99% as material, in a vacuum higher than 3×10 -5 Under the condition of 1.50 Pa, a vanadium dioxide film (4) with a thickness of 50-100 nm is evaporated on the upper surface of the graphene film (3); S4, sputtering a 50-100 nm layer of titanium dioxide film (5) on the surface of the vanadium dioxide film (4); and simultaneously sputtering a 100 nm layer of silicon nitride film (6) on the titanium dioxide film (5); S5. Using vacuum packaging technology, the optical window is sealed and connected with the graphene film (3), the vanadium dioxide film (4) and the titanium dioxide film (5), thereby completing the production of the detector.
5. A method for preparing a composite structure infrared photoelectric detector according to claim 1, characterized in that: The steps include: S1. Cut the N-type silicon substrate with a thickness of 500 μm and containing the readout circuit (1) and the optical microcavity into 0.5×1 cm 2 size, ultrasonically treated with acetone and alcohol for 10 minutes, then ultrasonically treated with deionized water for 5 minutes, and then dried with a nitrogen gun to obtain an N-type silicon substrate (2); S2, using microwave plasma chemical vapor deposition technology to grow a graphene film (3) inside the optical microcavity on the top of the N-type silicon substrate (2), with a thickness of 20-100 nm; S3, using magnetron sputtering coating technology, with VO2 target with purity of 99.99% as material, in a vacuum higher than 3×10 -5 Under the condition of 1.50 Pa, a vanadium dioxide film (4) with a thickness of 50-100 nm is evaporated on the upper surface of the graphene film (3); S4, sputtering a 50-100 nm layer of titanium dioxide film (5) on the surface of the vanadium dioxide film (4); and simultaneously sputtering a 150 nm layer of silicon nitride film (6) on the titanium dioxide film (5); S5. Using vacuum packaging technology, the optical window is sealed and connected with the graphene film (3), the vanadium dioxide film (4) and the titanium dioxide film (5), thereby completing the production of the detector.
6. A method for preparing a composite structure infrared photoelectric detector according to claim 1, characterized in that: The steps include: S1. Cut the N-type silicon substrate with a thickness of 500 μm and containing the readout circuit (1) and the optical microcavity into 0.5×1 cm 2 size, ultrasonically treated with acetone and alcohol for 10 minutes, then ultrasonically treated with deionized water for 5 minutes, and then dried with a nitrogen gun to obtain an N-type silicon substrate (2); S2, using microwave plasma chemical vapor deposition technology to grow a graphene film (3) inside the optical microcavity on the top of the N-type silicon substrate (2), with a thickness of 20-100 nm; S3, using magnetron sputtering coating technology, with VO2 target with purity of 99.99% as material, in a vacuum higher than 3×10 -5 Under the condition of 1.5 Å Pa, a vanadium dioxide film (4) with a thickness of 100 nm is evaporated on the upper surface of the graphene film (3); S4, sputtering a 50-100 nm layer of titanium dioxide film (5) on the surface of the vanadium dioxide film (4); and simultaneously sputtering a 50-100 nm layer of silicon nitride film (6) on the titanium dioxide film (5); S5. Using vacuum packaging technology, the optical window is sealed and connected with the graphene film (3), the vanadium dioxide film (4) and the titanium dioxide film (5), thereby completing the production of the detector.