Nanowire film infrared detector and preparation method thereof

Abstract

The invention discloses a nanowire film infrared detector and a preparation method thereof, the nanowire film infrared detector comprises two Al2O3 gemstone substrates which are arranged in a spaced manner, and a Mn-Co-Ni-O nanowire film, two electrodes and two electrode leads which are sequentially arranged on the Al2O3 gemstone substrates, and the Mn-Co-Ni-O nanowire film is suspended on the two Al2O3 gemstone substrates; the preparation method of the detector comprises the following steps: firstly, preparing the Mn-Co-Ni-O nanowire with the high length-diameter ratio by adopting a hydrothermal method, then carrying out suction filtration on the Mn-Co-Ni-O nanowire dispersion liquid to form a film, cutting the nanowire film, then placing the nanowire film on the Al2O3 gemstone substrate in a suspended manner, and finally preparing the electrode and welding the lead. According to the detector provided by the invention, the thermal conductivity is reduced due to the suspended structure, and the network-shaped nanowire film has a high resistance temperature coefficient, so that the response rate of the device can be remarkably enhanced, and high-sensitivity infrared detection is realized.

Description

Technical Field

[0001] This invention relates to the field of infrared detector technology, and in particular to a nanowire film infrared detector and its preparation method. Background Technology

[0002] As an important component of uncooled infrared detectors, thermistors utilize the thermal effect of radiation, achieving radiation detection through thermoelectric changes. They offer advantages such as room temperature operation, simple circuitry, and ease of use. Manganese cobalt nickel oxide (Mn-Co-Ni-O) is a well-developed thermistor material with a high temperature coefficient of resistance (TCR), a wide optical response band, stable performance, and a broad operating temperature range, making it crucial for applications in infrared detectors.

[0003] With the rapid development of technology, the demand for high sensitivity and lightweight detection has emerged, posing new challenges to Mn-Co-Ni-O detectors and necessitating further improvements in their performance. According to the theoretical formula for thermal detectors, the device responsivity is inversely proportional to thermal conductivity and directly proportional to thermal chromatographic response (TCR). Therefore, to improve the sensitivity of thermal detectors, it is necessary to minimize the thermal conductivity and increase the TCR of the thermal element. Summary of the Invention

[0004] The purpose of this invention is to provide a nanowire film infrared detector and its preparation method, which breaks through the bottleneck of the difficulty in improving the sensitivity of existing uncooled infrared detectors and achieves high-performance infrared detection.

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

[0006] A nanowire film infrared detector has a suspended structure comprising two spaced-apart Al2O3 sapphire substrates and a Mn-Co-Ni-O nanowire film mounted on the two Al2O3 sapphire substrates, with both ends of the Mn-Co-Ni-O nanowire film respectively disposed on the two Al2O3 sapphire substrates; the nanowire film infrared detector also includes two electrodes and two electrode leads, with the two electrodes respectively disposed on both ends of the Mn-Co-Ni-O nanowire film, and each electrode leading out one electrode lead, wherein the electrodes are Cr / Au electrodes.

[0007] The aforementioned method for preparing the nanowire film infrared detector includes the following steps:

[0008] Step 1: Prepare Mn-Co-Ni-O nanowires using a hydrothermal method:

[0009] Manganese acetate, cobalt acetate, and nickel acetate were dissolved in deionized water, and then sodium dodecylbenzenesulfonate was added to prepare a homogeneous growth solution. The growth solution was transferred to a reaction vessel and heated. After the reaction vessel cooled naturally to room temperature, the precipitate was removed. The precipitate was placed in deionized water, sonicated, and then centrifuged and washed. The process of sonicating and centrifuging the precipitate in deionized water was repeated at least five times. After drying, high aspect ratio Mn-Co-Ni-O nanowires were obtained.

[0010] Step 2, Preparation of Mn-Co-Ni-O nanowire film:

[0011] The Mn-Co-Ni-O nanowires prepared in step one are dispersed in deionized water and ultrasonically treated to obtain a uniform nanowire dispersion. This nanowire dispersion is then vacuum filtered to obtain a wet nanowire film. The wet nanowire film is then transferred to a glass substrate and dried before being peeled off from the glass substrate to obtain a Mn-Co-Ni-O nanowire film.

[0012] Step 3, prepare the suspended structure:

[0013] The Mn-Co-Ni-O nanowire film prepared in step two is cut into thin strips, and its two ends are placed on two mutually spaced Al2O3 gemstone substrates for support to form a suspended structure.

[0014] Step 4, Electrode preparation:

[0015] Cr / Au electrodes were fabricated at both ends of the Mn-Co-Ni-O nanowire film and the electrode leads were spot-welded together.

[0016] In step one, the molar ratio of manganese acetate, cobalt acetate, and nickel acetate is Mn:Co:Ni = 30-55:30-45:15-30; the growth solution is heated in a sealed reactor for 4-10 hours at a temperature of 100℃-190℃; the precipitate is placed in deionized water, ultrasonicated, centrifuged and washed, and then dried at 60℃ for 12 hours to obtain high aspect ratio Mn-Co-Ni-O nanowires.

[0017] In step two, the wet nanowire film transferred to the glass substrate needs to be dried at 60°C for 12 hours before it can be peeled off from the glass substrate to obtain the Mn-Co-Ni-O nanowire film.

[0018] In step four, Cr / Au electrodes are prepared by dual-ion beam sputtering with an electrode thickness of 20 nm / 100 nm, and the electrode leads are connected using an ultrasonic spot welder.

[0019] In view of the above technical features, the present invention has the following beneficial effects:

[0020] 1. The hydrothermal method described in this invention can prepare high aspect ratio Mn-Co-Ni-O nanowires. The preparation process is simple and the nanowire yield is high. 2. In this invention, after filtering Mn-Co-Ni-O nanowires dispersed in deionized water to form a membrane, the nanowires form a cross-network. The presence of junctions between the nanowires significantly reduces heat transfer efficiency and enhances temperature response. This results in the Mn-Co-Ni-O nanowire membrane of the thermistor having a high TCR, which can significantly enhance the device responsivity and achieve high-sensitivity infrared detection. 3. The nanowire membrane infrared detector of this invention has a suspended structure, which can greatly reduce thermal conductivity and significantly improve the device responsivity. 4. The nanowire membrane infrared detector of this invention uses ordinary Al2O3 sapphire as a support substrate, which is low in cost. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the nanowire film infrared detector of the present invention.

[0022] Figure 2 This is a flowchart of the preparation method of the nanowire film infrared detector of the present invention.

[0023] Figure 3 This is a scanning electron microscope image of the high aspect ratio Mn-Co-Ni-O nanowires prepared in this invention.

[0024] In the figure: 1-Al2O3 gemstone substrate; 2-Mn-Co-Ni-O nanowire film; 3-Electrode; 4-Electrode lead. Detailed Implementation

[0025] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0026] A nanowire film infrared detector, such as Figure 1 As shown, the nanowire film infrared detector has a suspended structure, which includes two spaced Al2O3 sapphire substrates 1 and a Mn-Co-Ni-O nanowire film 2 mounted on the two Al2O3 sapphire substrates 1. The two ends of the Mn-Co-Ni-O nanowire film 2 are respectively disposed on the two Al2O3 sapphire substrates 1. The suspended structure can greatly reduce thermal conductivity and significantly improve the responsivity of the device.

[0027] The nanowire film infrared detector also includes two electrodes 3 and two electrode leads 4. The two electrodes 3 are respectively disposed on both ends of the Mn-Co-Ni-O nanowire film 2, and each electrode 3 leads out an electrode lead 4. The electrodes 3 are Cr / Au electrodes.

[0028] like Figure 2 As shown, the aforementioned method for fabricating a nanowire film infrared detector is characterized by comprising the following steps:

[0029] Step 1: Prepare Mn-Co-Ni-O nanowires using a hydrothermal method:

[0030] Manganese acetate, cobalt acetate, and nickel acetate were dissolved in deionized water, and then sodium dodecylbenzenesulfonate was added to prepare a homogeneous growth solution. The growth solution was transferred to a reaction vessel and heated. After the reaction vessel cooled naturally to room temperature, the precipitate was removed. The precipitate was placed in deionized water, sonicated, and then centrifuged and washed. The process of sonicating and centrifuging the precipitate in deionized water was repeated at least five times. After drying, high aspect ratio Mn-Co-Ni-O nanowires were obtained.

[0031] The molar ratio of manganese acetate, cobalt acetate, and nickel acetate is Mn:Co:Ni = 30-55:30-45:15-30; the growth solution is heated in a sealed reactor for 4-10 hours at 100℃-190℃; the precipitate is placed in deionized water, ultrasonically washed, centrifuged, and then dried at 60℃ for 12 hours to obtain the desired product. Figure 3 The high aspect ratio Mn-Co-Ni-O nanowires shown.

[0032] Step 2, Preparation of Mn-Co-Ni-O nanowire film 2:

[0033] The Mn-Co-Ni-O nanowires prepared in step one were dispersed in deionized water and ultrasonically treated to obtain a uniform nanowire dispersion. This nanowire dispersion was then vacuum filtered to obtain a wet nanowire membrane. During the filtration process, agglomeration was prevented to ensure that the Mn-Co-Ni-O nanowires were uniformly distributed on the cellulose membrane filter to form a membrane. The wet nanowire membrane was then transferred to a glass substrate, dried, and then peeled off from the glass substrate to obtain Mn-Co-Ni-O nanowire membrane 2.

[0034] The nanowire wet film needs to be dried at 60°C for 12 hours after being transferred to the glass substrate before it can be peeled off from the glass substrate to obtain the Mn-Co-Ni-O nanowire film 2.

[0035] Step 3, prepare the suspended structure:

[0036] The Mn-Co-Ni-O nanowire film 2 prepared in step two is cut into thin strips, and its two ends are placed on two mutually spaced Al2O3 gemstone substrates 1 for support to form a suspended structure.

[0037] Step 4, prepare electrode 3:

[0038] Electrodes 3 were fabricated at both ends of the Mn-Co-Ni-O nanowire film 2, and electrode leads 4 were spot-welded to them.

[0039] Cr / Au electrodes were prepared by dual-ion beam sputtering. The thickness of electrode 3 was 20 nm / 100 nm. Electrode leads 4 were connected by an ultrasonic spot welder.

[0040] Example 1 of the preparation method of the nanowire film infrared detector of the present invention:

[0041] Step 1: Weigh manganese acetate, cobalt acetate, and nickel acetate in a molar ratio of Mn:Co:Ni = 55:30:15, and dissolve them in 25 ml of deionized water to prepare a 0.1 M solution. Then, add 1 mmol of sodium dodecylbenzenesulfonate to the solution and sonicate for 15 minutes to prepare a homogeneous growth solution. Transfer the growth solution to a 50 ml reactor. Seal the reactor and heat at 130 °C for 5 hours. After the reactor cools naturally to room temperature, remove the sample and wash it in deionized water by sonication and centrifugation at least 5 times. Finally, dry at 60 °C for 12 hours.

[0042] Step 2: Add 10 mg of Mn-Co-Ni-O nanowires to 30 ml of deionized water and sonicate to obtain a uniform nanowire dispersion. Vacuum filter the dispersion through a cellulose membrane filter, preventing agglomeration during filtration to ensure the Mn-Co-Ni-O nanowires are uniformly distributed on the filter to form a membrane. Wash with deionized water, then transfer the wet Mn-Co-Ni-O nanowire membrane to a glass substrate. After drying at 60°C for 12 hours, peel the membrane off the substrate to obtain Mn-Co-Ni-O nanowire membrane 2.

[0043] Step 3: Cut the Mn-Co-Ni-O nanowire film 2 into thin strips 8 mm long and 0.5 mm wide, and place them on the Al2O3 gemstone substrate 1 for support to form a suspended structure.

[0044] Step 4: Use a mask template to protect the electrode 3 and spot weld the electrode lead 4; use dual ion beam sputtering to prepare Cr / Au electrodes with a thickness of 20nm / 100nm, and use an ultrasonic spot welder to connect the metal leads.

[0045] Example 2:

[0046] Step 1: Weigh manganese acetate, cobalt acetate, and nickel acetate in a molar ratio of Mn:Co:Ni = 32:40:28, and dissolve them in 25 ml of deionized water to prepare a 0.1 M solution. Then, add 1 mmol of sodium dodecylbenzenesulfonate to the solution and sonicate for 15 minutes to prepare a homogeneous growth solution. Transfer the growth solution to a 50 ml reactor. Seal the reactor and heat at 130 °C for 5 hours. After the reactor cools naturally to room temperature, remove the sample, sonicate and centrifuge it repeatedly in deionized water, and finally dry it at 60 °C for 12 hours.

[0047] Step 2: Add 10 mg of Mn-Co-Ni-O nanowires to 30 ml of deionized water and sonicate to obtain a uniform nanowire dispersion. Vacuum filter the dispersion through a cellulose membrane filter, preventing agglomeration during filtration to ensure the Mn-Co-Ni-O nanowires are uniformly distributed on the filter to form a membrane. Wash with deionized water, then transfer the wet Mn-Co-Ni-O nanowire membrane to a glass substrate. After drying at 60°C for 12 hours, peel the membrane off the substrate to obtain Mn-Co-Ni-O nanowire membrane 2.

[0048] Step 3: Cut the Mn-Co-Ni-O nanowire film into thin strips 8 mm long and 0.5 mm wide, and place them on the Al2O3 gemstone substrate 1 for support to form a suspended structure.

[0049] Step 4: Use a mask template to protect the electrode 3 and spot weld the electrode lead 4; use dual ion beam sputtering to prepare Cr / Au electrodes with a thickness of 20nm / 100nm, and use an ultrasonic spot welder to connect the metal leads.

[0050] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A nanowire film infrared detector, characterized in that: The nanowire film infrared detector has a suspended structure, which includes two Al2O3 gemstone substrates (1) placed separately, and a Mn-Co-Ni-O nanowire film (2) mounted on the two Al2O3 gemstone substrates (1). The two ends of the Mn-Co-Ni-O nanowire film (2) are respectively mounted on the two Al2O3 gemstone substrates (1). The nanowire film infrared detector also includes two electrodes (3) and two electrode leads (4). The two electrodes (3) are respectively mounted on the two ends of the Mn-Co-Ni-O nanowire film (2), and each electrode (3) leads out an electrode lead (4). Among them, the electrode (3) is a Cr / Au electrode.

2. The method for preparing the nanowire film infrared detector as described in claim 1, characterized in that: Includes the following steps: Step 1: Prepare Mn-Co-Ni-O nanowires using a hydrothermal method: Manganese acetate, cobalt acetate, and nickel acetate were dissolved in deionized water, and then sodium dodecylbenzenesulfonate was added to prepare a homogeneous growth solution. The growth solution was transferred to a reaction vessel and heated. After the reaction vessel cooled naturally to room temperature, the precipitate was removed. The precipitate was placed in deionized water, sonicated, and then centrifuged and washed. The process of sonicating and centrifuging the precipitate in deionized water was repeated at least five times. After drying, high aspect ratio Mn-Co-Ni-O nanowires were obtained. Step 2, Preparation of Mn-Co-Ni-O nanowire film (2): The Mn-Co-Ni-O nanowires prepared in step one were dispersed in deionized water and ultrasonically treated to obtain a uniform nanowire dispersion. This nanowire dispersion was vacuum filtered to obtain a wet nanowire film. The wet nanowire film was then transferred to a glass substrate and dried before being peeled off from the glass substrate to obtain a Mn-Co-Ni-O nanowire film (2). Step 3, prepare the suspended structure: The Mn-Co-Ni-O nanowire film (2) prepared in step 2 was cut into thin strips, and its two ends were placed on two mutually separated Al2O3 gemstone substrates (1) for support to form a suspended structure. Step 4, Electrode preparation (3): Cr / Au electrodes (3) were prepared at both ends of the Mn-Co-Ni-O nanowire film (2), and electrode leads (4) were spot-welded together.

3. The method for preparing the nanowire film infrared detector as described in claim 2, characterized in that: In step one, the molar ratio of manganese acetate, cobalt acetate, and nickel acetate is Mn:Co:Ni = 30-55:30-45:15-30; the growth solution is heated in a sealed reactor for 4-10 hours at a temperature of 100℃-190℃; the precipitate is placed in deionized water, ultrasonicated, centrifuged and washed, and then dried at 60℃ for 12 hours to obtain high aspect ratio Mn-Co-Ni-O nanowires.

4. The method for preparing the nanowire film infrared detector as described in claim 2, characterized in that: In step two, the nanowire wet film is transferred to the glass substrate and dried at 60°C for 12 hours before it can be peeled off from the glass substrate to obtain the Mn-Co-Ni-O nanowire film (2).

5. The method for preparing the nanowire film infrared detector as described in claim 2, characterized in that: In step four, a Cr / Au electrode (3) is prepared by dual ion beam sputtering. The electrode (3) has a thickness of 20 nm / 100 nm. The electrode leads (4) are connected by an ultrasonic spot welder.

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