Nanowire array / film composite infrared detector and preparation method thereof
By fabricating a composite structure of Mn-Co-Ni-O thin film and nanowire array on a gemstone substrate, the problem of insufficient sensitivity in uncooled infrared detectors was solved, achieving high sensitivity and low cost infrared detection.
Patent Information
- Application Number
- CN202511624315.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-07
- Publication Date
- 2026-02-13
AI Technical Summary
The sensitivity of existing uncooled infrared detectors is difficult to improve, especially given the need for high sensitivity and lightweight design. Further improvements in the performance of thermal detectors are required.
A nanowire array/thin film composite infrared detector structure is adopted, which includes sequentially setting Mn-Co-Ni-O thin film and Mn-Co-Ni-O nanowire array on a sapphire substrate, and preparing Mn-Co-Ni-O thin film and nanowire array by wet chemical method and hydrothermal method, and combining them with Cr/Au electrode to form a highly efficient electrode connection.
It achieves high-sensitivity infrared detection, reduces thermal conductivity, improves device responsivity, and reduces costs by using a synthetic gemstone substrate, while also possessing enhanced light-trapping performance and stability.
Smart Images
Figure CN121531797A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of infrared detector, in particular to a nanowire array / thin film composite infrared detector and a preparation method thereof. BACKGROUND
[0002] As an important component of uncooled infrared detector, thermal detector is to realize radiation detection through thermal-electric change by using thermal effect of radiation, which has the advantages of room temperature operation, simple use circuit and convenient operation. Manganese-cobalt-nickel oxide (Mn-Co-Ni-O) is a relatively mature thermal resistance detection material. The oxide has spinel structure, high resistance temperature coefficient, wide light response band, stable performance and wide use temperature range, and has important application in infrared detector.
[0003] With the rapid development of science and technology, high sensitivity and light weight detection requirements are proposed, and Mn-Co-Ni-O detector also faces new challenges, and the performance of thermal detector needs to be further improved. According to the theoretical formula of thermal detector, the response rate of the device is proportional to the absorption and inversely proportional to the thermal conductivity. Therefore, in order to improve the sensitivity of the thermal detector, it is necessary to reduce the thermal conductivity of the device as much as possible and increase the absorption. One-dimensional nanostructured materials exhibit unique physical properties such as high surface volume ratio, surface and interface effects due to their limited dimension and size reduction. In particular, nanowire arrays can capture light and increase absorption, which can improve the response rate when applied to radiation detection. The influence of the substrate on the thermal detector is significant, and thinning the thickness of the substrate is beneficial to reduce the thermal conductivity and improve the response rate of the device. SUMMARY
[0004] The present application aims to provide a nanowire array / thin film composite infrared detector and a preparation method thereof, which breaks through the bottleneck of difficult improvement of the sensitivity of the existing uncooled infrared detector and realizes high-performance infrared detection.
[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present application is:
[0006] A nanowire array / thin film composite infrared detector, the infrared detector comprises Mn-Co-Ni-O thin film, Mn-Co-Ni-O nanowire array, electrode and electrode lead which are arranged in the order from bottom to top on a gem substrate; wherein the gem substrate is Al2O3 gem sheet with a thickness of 0.07 mm; the thickness of the Mn-Co-Ni-O thin film is 4.0-8.0 microns, the height of the Mn-Co-Ni-O nanowire array is 2.0-6.0 microns, and the electrode is Cr / Au electrode.
[0007] The preparation method of the nanowire array / thin film composite infrared detector comprises the following steps:
[0008] Step one, select Al2O3 gem slice made of gem substrate, after cleaning and drying for standby;
[0009] Step two, the preparation of thin film samples;
[0010] The thickness of the Mn-Co-Ni-O thin film prepared on the gem substrate by wet chemical method is 4.0-8.0 microns, that is, the thin film sample is obtained;
[0011] Step three, preparation of composite structure sample;
[0012] The thickness of the Mn-Co-Ni-O nanowire array grown on the Mn-Co-Ni-O thin film of the sample prepared in step two by hydrothermal method is 2.0-6.0 microns; then after cleaning and drying, heat to 400℃ and keep for 2 hours, then cool to room temperature to obtain Mn-Co-Ni-O nanowire array / thin film composite structure sample;
[0013] Step four, preparation of electrode;
[0014] On the composite structure sample, use mask plate protection to prepare electrode, spot welding connection electrode lead.
[0015] In step two, manganese acetate, cobalt acetate and nickel acetate are selected as raw materials, glacial acetic acid is used as solvent, and precursor solution with component molar ratio of Mn:Co:Ni = 52:32:16 is prepared, then uniform coating machine and rapid annealing furnace are used to prepare Mn-Co-Ni-O thin film with thickness of 4.0-8.0 microns.
[0016] In step three, manganese chloride, cobalt chloride and nickel chloride are dissolved in deionized water, with component molar ratio of Mn:Co:Ni = 30-55:25-60:15-40, then after adding urea, fully stirring and mixing, uniform growth solution is prepared, and the growth solution is transferred to the reaction kettle, then the sample prepared in step two is immersed in the growth solution, the reaction kettle is sealed and heated at 100℃-150℃ for 5-8 hours; after the reaction kettle is naturally cooled to room temperature, the sample is washed with deionized water several times, then dried at 60℃ for 12 hours; then the sample is heated to 400℃ at a heating rate of 2℃ / min in a muffle furnace and kept for 2 hours, and cooled to room temperature to obtain the composite structure sample with Mn-Co-Ni-O nanowire array with height of 2.0-6.0 microns on the Mn-Co-Ni-O thin film.
[0017] In step four, the composite structure sample is cut into slices, then protected by mask plate, Cr / Au electrode with thickness of 20nm / 100nm is prepared by dual ion beam sputtering, and then electrode lead is connected using ultrasonic spot welding machine.
[0018] In view of the above technical features, the present invention has the following beneficial effects:
[0019] 1. This invention selects an ultrathin Al2O3 sapphire sheet as the substrate, which not only helps reduce thermal conductivity and improve the device's responsivity, but also, as the substrate is a synthetic gemstone, significantly reduces costs. 2. The Mn-Co-Ni-O thin film not only has a high temperature coefficient of resistance, but also exhibits better density and stability than bulk ceramic materials. Incident light is reflected and absorbed within the Mn-Co-Ni-O nanowire array, resulting in enhanced light-trapping performance. The Mn-Co-Ni-O nanowire array / thin film composite structure combines the light-trapping effect of nanowire arrays with the advantages of a high temperature coefficient of resistance and stable performance of thin films, enabling high-sensitivity infrared detection. 3. The hydrothermal method allows direct growth of Mn-Co-Ni-O nanowire arrays on the Mn-Co-Ni-O thin film. The Mn-Co-Ni-O thin film itself is not only an excellent thermosensitive detection material, but can also serve as a seed layer to control the morphology of the nanowire array. The fabrication process of this composite structure has inherent advantages. 4. The infrared detector of this invention has a clear structure, a simple fabrication process, and broad application prospects. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the structure of the nanowire array / thin film composite infrared detector of the present invention.
[0021] Figure 2 This is a flowchart of the fabrication method of the nanowire array / thin film composite infrared detector of the present invention.
[0022] In the figure: 1-Gemstone substrate; 2-Mn-Co-Ni-O thin film; 3-Mn-Co-Ni-O nanowire array; 4-Electrode; 5-Electrode lead. Detailed Implementation
[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these drawings and embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that some components well-known to those skilled in the art but not related to the main content of the present invention may be omitted in the drawings or description. Additionally, for ease of description, some components in the drawings may be omitted, enlarged, or reduced, but this does not represent the actual size or complete structure of the product.
[0024] A nanowire array / thin film composite infrared detector, such as Figure 1 As shown, the infrared detector includes a Mn-Co-Ni-O thin film 2, a Mn-Co-Ni-O nanowire array 3, an electrode 4, and an electrode lead 5, which are arranged sequentially from bottom to top on a sapphire substrate 1.
[0025] Preferably, the gemstone substrate 1 is an ultrathin substrate made of Al2O3 gemstone sheet with a thickness of 0.07 mm; this not only helps to reduce thermal conductivity and improve the response rate of the device, but also the substrate is a synthetic gemstone, which significantly reduces the manufacturing cost.
[0026] The Mn-Co-Ni-O thin film 2 has a thickness of 4.0-8.0 micrometers, while the Mn-Co-Ni-O nanowire array 3 has a thickness of 2.0-6.0 micrometers. The Mn-Co-Ni-O thin film 2 not only possesses a high temperature coefficient of resistance but also exhibits better density and stability than bulk ceramic materials. When incident light is reflected in the Mn-Co-Ni-O nanowire array 3, it is accompanied by absorption, resulting in enhanced light-trapping performance. This composite detector combines the light-trapping enhanced absorption of the Mn-Co-Ni-O nanowire array 3 with the advantages of the high temperature coefficient of resistance and stable performance of the Mn-Co-Ni-O thin film 2, and holds promise for achieving high-sensitivity infrared detection.
[0027] Electrode 4 is a Cr / Au electrode.
[0028] The method for fabricating the nanowire array / thin film composite infrared detector of the present invention, as follows: Figure 2 As shown, it includes the following steps:
[0029] Step 1: Select gem substrate 1 made of Al2O3 gem sheet, clean and dry it for later use;
[0030] Reducing the thickness of the substrate can improve the response rate of the device, but a substrate that is too thin is fragile and has poor maneuverability. This patent uses an ultra-thin Al2O3 sapphire substrate with a thickness of 0.07 mm. The substrate is cleaned using conventional methods to remove impurities and contaminants from its surface, and then dried for later use.
[0031] Step 2: Prepare thin film samples;
[0032] A Mn-Co-Ni-O thin film 2 with a thickness of 4.0-8.0 micrometers was prepared on a gemstone substrate 1 using a wet chemical method, thus obtaining the thin film sample;
[0033] Specifically, manganese acetate, cobalt acetate, and nickel acetate were selected as raw materials, and glacial acetic acid was used as solvent to prepare a precursor solution with a component molar ratio of Mn:Co:Ni = 52:32:16. Then, a spin coater and a rapid annealing furnace were used to prepare Mn-Co-Ni-O thin films with a thickness of 4.0-8.0 micrometers.
[0034] Step 3: Prepare composite structure samples;
[0035] Mn-Co-Ni-O nanowire arrays 3 with a thickness of 2.0-6.0 μm were grown on the Mn-Co-Ni-O thin film 2 prepared in step 2 by hydrothermal method; then, after cleaning and drying, the film was heated to 400℃ and held for 2 hours, and then cooled to room temperature to obtain the Mn-Co-Ni-O nanowire array / thin film composite structure sample.
[0036] Specifically, manganese chloride, cobalt chloride, and nickel chloride are dissolved in deionized water with a molar ratio of Mn:Co:Ni = 30-55:25-60:15-40. Urea is then added and the mixture is stirred thoroughly to prepare a homogeneous growth solution. The growth solution is transferred to a reaction vessel, and the sample obtained in step two is immersed in the growth solution. The reaction vessel is sealed and heated at 100℃-150℃ for 5-8 hours. After the reaction vessel cools naturally to room temperature, the sample is removed, washed several times with deionized water, and then dried at 60℃ for 12 hours. The sample is then heated to 400℃ in a muffle furnace at a heating rate of 2℃ / min and held for 2 hours. After cooling to room temperature, a composite structure sample with a height of 2.0-6.0 micrometers of Mn-Co-Ni-O nanowire array 3 grown on Mn-Co-Ni-O film 2 is obtained.
[0037] Step 4, prepare electrode 4;
[0038] Electrode 4 was fabricated on the composite structure sample using a mask template, and electrode leads 5 were spot-welded together.
[0039] The composite structure sample was divided into slices, then protected with a mask template, and Cr / Au electrodes were prepared by dual ion beam sputtering with a thickness of 20 nm / 100 nm. The electrode leads were then connected using an ultrasonic spot welder. Specific Implementation Example 1:
[0041] Step 1: Using manganese acetate, cobalt acetate, and nickel acetate as solutes and glacial acetic acid as solvent, prepare 30 ml of a 0.5 M precursor solution with a component molar ratio of Mn:Co:Ni = 52:32:16. Drop the precursor solution onto a 0.07 mm thick Al₂O₃ sapphire substrate 1, and spin-coat it using a spin coater at 3000 rpm for 30 seconds to obtain a wet film. Place the wet film in a rapid annealing furnace for heat treatment under the following conditions: heat to 250 °C in 10 seconds and hold for 1 minute; then heat to 750 °C in 10 seconds and hold for 10 minutes. Repeat the spin-coating, spin-coating, and heat treatment process until a 5.0 μm thick Mn-Co-Ni-O thin film 2 is obtained.
[0042] Step 2: Using manganese chloride, cobalt chloride, and nickel chloride as solutes, and deionized water as solvent, urea solution (molar ratio of urea:chloride = 2:1) was added to prepare 25 ml of a 0.1 M growth solution with a component molar ratio of Mn:Co:Ni = 52:32:16. This growth solution was then transferred to a 50 ml reactor. An Al2O3 gemstone substrate with a Mn-Co-Ni-O thin film 2 was immersed in the growth solution. The reactor was sealed and heated at 100 °C for 6 hours. After cooling to room temperature, the sample was removed, washed three times with deionized water, and then dried at 60 °C for 12 hours. The sample was then heated to 400 °C in a muffle furnace and held for 2 hours. After cooling to room temperature, a composite structure sample with a Mn-Co-Ni-O nanowire array 3 with a height of approximately 2.0 μm was obtained grown on a 5.0 μm thick Mn-Co-Ni-O thin film 2.
[0043] Step 3: Cut the composite structure sample, prepare the Cr / Au electrode, and spot weld the electrode leads 5.
[0044] Example 2:
[0045] Step 1: Using manganese acetate, cobalt acetate, and nickel acetate as solutes and glacial acetic acid as solvent, prepare 30 ml of a 0.5 M precursor solution with a component molar ratio of Mn:Co:Ni = 52:32:16. Drop the precursor solution onto a 0.07 mm thick Al₂O₃ sapphire substrate 1, and spin-coat it using a spin coater at 3000 rpm for 30 seconds to obtain a wet film. Place the wet film in a rapid annealing furnace for heat treatment under the following conditions: heat to 250 °C in 10 seconds and hold for 1 minute; then heat to 750 °C in 10 seconds and hold for 10 minutes. Repeat the spin-coating, spin-coating, and heat treatment process until a 5.0 μm thick Mn-Co-Ni-O thin film 2 is obtained.
[0046] Step 2: Using manganese chloride, cobalt chloride, and nickel chloride as solutes, and deionized water as solvent, urea solution (molar ratio of urea:chloride = 2:1) was added to prepare 25 ml of a 0.1 M growth solution with a component molar ratio of Mn:Co:Ni = 52:32:16. This growth solution was then transferred to a 50 ml reactor. An Al2O3 gemstone substrate with a Mn-Co-Ni-O thin film 2 was immersed in the growth solution. The reactor was sealed and heated at 120 °C for 6 hours. After cooling to room temperature, the sample was removed, washed three times with deionized water, and then dried at 60 °C for 12 hours. The sample was then heated to 400 °C in a muffle furnace and held for 2 hours. After cooling to room temperature, a composite structure sample with a Mn-Co-Ni-O nanowire array 3 with a height of approximately 3.0 μm was obtained grown on a 5.0 μm thick Mn-Co-Ni-O thin film 2.
[0047] Step 3: Cut the composite structure sample, prepare the Cr / Au electrode, and spot weld the electrode leads 5.
[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the invention. All equivalent changes and modifications made within the scope of the claims of this invention should be considered within the technical scope of this invention.
Claims
1. A nanowire array / thin film composite infrared detector, characterized in that: The infrared detector comprises a Mn-Co-Ni-O thin film (2), a Mn-Co-Ni-O nanowire array (3), an electrode (4), and an electrode lead (5) arranged sequentially from bottom to top on a sapphire substrate (1); wherein the sapphire substrate (1) is an Al2O3 sapphire sheet with a thickness of 0.07 mm; the Mn-Co-Ni-O thin film (2) has a thickness of 4.0-8.0 μm, the Mn-Co-Ni-O nanowire array (3) has a height of 2.0-6.0 μm, and the electrode (4) is a Cr / Au electrode.
2. The method for fabricating the nanowire array / thin film composite infrared detector as described in claim 1, characterized in that: Includes the following steps: Step 1: Select a gemstone substrate (1) made of Al2O3 gemstone sheet, clean it and dry it for later use; Step 2: Prepare thin film samples; Mn-Co-Ni-O thin films (2) with a thickness of 4.0-8.0 micrometers were prepared on a gemstone substrate (1) using a wet chemical method, thus obtaining the thin film sample; Step 3: Prepare composite structure samples; Mn-Co-Ni-O nanowire arrays (3) with a height of 2.0-6.0 μm were grown on the Mn-Co-Ni-O thin film (2) prepared in step 2 by hydrothermal method; then the samples were cleaned and dried, heated to 400℃ and kept at that temperature for 2 hours, and then cooled to room temperature to obtain the Mn-Co-Ni-O nanowire array / thin film composite structure sample. Step 4, prepare the electrode (4); On the composite structure sample, electrodes were prepared using a mask template (4), and electrode leads were spot-welded together (5).
3. The method for fabricating the nanowire array / thin film composite infrared detector as described in claim 2, characterized in that: In step two, manganese acetate, cobalt acetate, and nickel acetate are selected as raw materials, and glacial acetic acid is used as solvent to prepare a precursor solution with a component molar ratio of Mn:Co:Ni = 52:32:
16. Then, a spin coater and a rapid annealing furnace are used to prepare Mn-Co-Ni-O films with a thickness of 4.0-8.0 micrometers.
4. The method for fabricating the nanowire array / thin film composite infrared detector as described in claim 2, characterized in that: In step three, manganese chloride, cobalt chloride and nickel chloride are dissolved in deionized water with a molar ratio of Mn:Co:Ni = 30-55:25-60:15-40. Urea is then added and thoroughly stirred to prepare a uniform growth solution. The growth solution is then transferred to a reaction vessel, and the sample obtained in step two is immersed in the growth solution. The reaction vessel is sealed and heated at 100℃-150℃ for 5-8 hours. After the reaction vessel cools naturally to room temperature, the sample is taken out, washed several times with deionized water, and then dried at 60℃ for 12 hours. The sample is then heated to 400℃ in a muffle furnace at a heating rate of 2℃ / min and held for 2 hours. After cooling to room temperature, a composite structure sample with a height of 2.0-6.0 micrometers of Mn-Co-Ni-O nanowire array (3) is obtained on the Mn-Co-Ni-O thin film (2).
5. The method for fabricating the nanowire array / thin film composite infrared detector as described in claim 2, characterized in that: In step four, the composite structure sample is divided into slices, then protected with a mask template, and Cr / Au electrodes are prepared by dual ion beam sputtering with a thickness of 20nm / 100nm. Then, the electrode leads are connected using an ultrasonic spot welder (5).