Molybdenum carbide semiconductor film, preparation, application and wide-temperature-range flexible temperature sensor
By combining molybdenum carbide semiconductor thin films with metal interdigitated electrodes, the problems of narrow temperature range, low accuracy, and insufficient flexibility of sensors were solved, realizing high-precision, fast-response wide-temperature range temperature monitoring, which is suitable for extreme environments and medical applications.
Patent Information
- Application Number
- CN202510829652.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-20
- Publication Date
- 2025-10-21
AI Technical Summary
Existing temperature sensors have a narrow detection range, low accuracy, and insufficient flexibility, which cannot meet the needs of real-time and accurate temperature monitoring in extreme environments.
A wide-temperature-range flexible temperature sensor was fabricated using molybdenum carbide semiconductor thin film as the sensing material through inkjet printing and annealing. Combined with metal interdigitated electrodes and an alumina protective layer, high-precision temperature detection was achieved.
It achieves an ultra-wide temperature range response of 25–1500℃, with fast response time and high-resolution temperature detection, making it suitable for real-time temperature monitoring in extreme environments and medical settings.
Smart Images
Figure CN120820249A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of semiconductor materials, specifically to a molybdenum carbide semiconductor film, its preparation, application and a wide-temperature-range flexible temperature sensor. Background Art
[0002] In recent years, accurate temperature control in aerospace, petrochemical, and other fields has gained increasing attention. For example, temperature monitoring of critical national equipment, such as space rocket engines and ultra-high-temperature molten salt pumps, not only provides real-time insights into the dynamics of these processes but also allows for accurate monitoring to prevent major accidents caused by excessive temperatures. Therefore, accurate temperature monitoring is crucial for both technological development and public safety. Extreme temperature sensors can be categorized as contact or non-contact based on their measurement method. Contact temperature sensors offer advantages such as high measurement accuracy and real-time response. The emergence of flexible temperature sensors provides a more comfortable option for real-time monitoring in wearable devices, greatly facilitating daily life. With the continuous advancement of technology, achieving real-time, accurate temperature monitoring over a wide temperature range plays an irreplaceable role in technological development. The research and development of flexible extreme temperature sensors is of great significance to contemporary scientific and technological progress. However, existing temperature sensors suffer from limitations such as a narrow temperature range, low accuracy, and insufficient flexibility. Therefore, the development of flexible temperature sensors with a wide temperature range is crucial. Summary of the Invention
[0003] The present invention provides a molybdenum carbide semiconductor film, its preparation, application and wide temperature range flexible temperature sensor, in order to provide a high-precision temperature sensor with both wide temperature range and good stability.
[0004] To achieve this goal, the following steps need to be implemented:
[0005] A method for preparing a molybdenum carbide semiconductor film comprises the following steps:
[0006] Step 1: After dissolving the molybdenum source and carbon source in water, add 1 / 3 volume of ethanol dropwise to prepare a precursor ink of molybdenum carbide material; the Mo / C molar ratio is 10:1;
[0007] Step 2: Deposit the precursor ink of molybdenum carbide material on the surface of the substrate. Then, under the condition of argon and hydrogen volume ratio of 1:1, keep it at 450℃ and then heat it to 550-1050℃ for annealing to obtain molybdenum carbide thin film material. The thickness of the film depends on the inkjet printing parameters.
[0008] Optionally, in the step 2, specifically, the temperature is kept at 450° C. for 30 minutes, and then the temperature is raised to 550-1050° C. for 10 minutes to perform annealing treatment for 1 hour.
[0009] Optionally, in step 2, the temperature is raised to 750° C. for annealing.
[0010] Optionally, the molybdenum source is ammonium molybdate, and the carbon source is a carbon-containing solid or a carbon-containing solvent; the carbon-containing solid is polyvinyl alcohol or glucose, and the carbon-containing solvent is ethylene glycol, propylene glycol or butanediol.
[0011] Optionally, in the step 2, the precursor ink of the molybdenum carbide material is deposited on the substrate by inkjet printing, and then the two-dimensional transition metal carbide is obtained by hydrogen reduction.
[0012] Optionally, specifically, the ammonium molybdate is first reduced to MoO2 at 450°C in an argon atmosphere, and then MoO2 and a carbon source are reduced under hydrogen, with the reduction temperature ranging from 550 to 1050°C.
[0013] Optionally, the substrate is one of mica, silicon wafer, glass, corundum and sapphire, and the thickness of the substrate is 0.01 to 2 mm.
[0014] A molybdenum carbide semiconductor film is prepared using any of the methods for preparing a molybdenum carbide semiconductor film described in the present invention.
[0015] The molybdenum carbide semiconductor film of the present invention is used to prepare a flexible temperature sensor with a wide temperature range.
[0016] A wide temperature range flexible temperature sensor, the preparation method comprising:
[0017] (1) Preparation of metal interdigitated electrodes on a substrate:
[0018] (2) preparing a molybdenum carbide semiconductor film as a sensitive layer on the metal interdigitated electrode using any of the methods for preparing a molybdenum carbide semiconductor film described in the present invention;
[0019] (3) A certain thickness of aluminum oxide is deposited on the surface of the sensitive layer as a protective layer by atomic layer deposition, and a molybdenum carbide alloy temperature sensor can be successfully prepared;
[0020] The metal interdigital electrode material is at least one of gold, platinum, copper, nickel and chromium, and is deposited by vacuum evaporation, magnetron sputtering, electron beam evaporation or physical vapor deposition, with a thickness of 5 to 200 nm;
[0021] Interdigitated electrodes with a line width and line spacing of 0.1 mm are formed on the substrate surface by laser etching technology.
[0022] The advantages of the present invention are:
[0023] 1. The flexible temperature sensor prepared by the present invention can respond to an ultra-wide temperature range, with a response range of 25 to 1500°C.
[0024] 2. The present invention proposes a novel method for synthesizing molybdenum carbide material by introducing a carbon source into ammonium molybdate. This method can synthesize molybdenum carbide under simpler and safer conditions.
[0025] 3. The present invention proposes a novel method for reducing and synthesizing molybdenum (Mo) metal by using ammonium molybdate, water and ethanol. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:
[0027] Figure 1 These are photos of the physical objects of Examples 1 to 6;
[0028] Figure 2 is a graph showing the resistance change rate versus temperature in Example 1;
[0029] Figure 3 is a graph showing the resistance change rate versus time in Experimental Example 1;
[0030] Figure 4 Optical photographs of platinum interdigitated electrodes prepared on the substrate surface for Examples 1 to 6;
[0031] Figure 5 These are optical images of the precursors of Examples 1 to 6 after being deposited on the surface of the interdigitated electrodes;
[0032] Figure 6 The XRD patterns of Mo2C synthesized in Examples 1 to 3 are shown;
[0033] Figure 7 XRD patterns of Mo2C synthesized in Examples 4 to 6;
[0034] Figure 8 This is the XRD pattern of Mo synthesized in Example 7; Figure 9 This is the XRD pattern of MoO2 synthesized in Example 8. DETAILED DESCRIPTION
[0035] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that for ordinary persons in this technical field, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.
[0036] The present invention is to prepare a high-precision and fast-response wide-temperature range temperature sensor to achieve real-time temperature monitoring in extreme environments and medical applications. The present invention provides a method for preparing a wide-temperature range, fast-response temperature sensor, which can be printed on different substrates to achieve flexible or non-flexible temperature sensing. The constructed molybdenum carbide film is a temperature-sensitive material. When the temperature changes, the resistance of the molybdenum carbide sensitive material will change. By measuring the resistance between the metal interdigitated electrodes, the temperature can be detected. The preparation of molybdenum carbide semiconductor film materials can also be used to prepare molybdenum carbide powder. The method used is low-cost, high-yield and simple to operate. It is a fast and efficient synthesis method. The temperature sensor has a simple structure, low cost, and can have a fast response and high resolution for temperature recognition within an ultra-wide temperature range (25-1500°C), and can achieve high-precision and rapid detection of extreme high-temperature environments.
[0037] Step 1: First, prepare the precursor ink of molybdenum carbide material. The specific method is to weigh a certain amount of ammonium molybdate powder and dissolve it in water, and then add a certain amount of ethanol solution and propylene glycol solution to the solution under magnetic stirring.
[0038] Step 2: Set the inkjet printing parameters to deposit the solution on the film surface.
[0039] Step 3: Anneal the prepared solution at 750°C under argon:hydrogen ratio of 1:1 to successfully synthesize molybdenum carbide material.
[0040] When synthesizing the molybdenum carbide precursor solution, the molybdenum source selected is ammonium molybdate tetrahydrate, and the carbon source selected can be a carbon-containing solid (organic polymers or monosaccharides such as polyvinyl alcohol and glucose) or a carbon-containing solvent (polyol compounds such as ethylene glycol, propylene glycol, and butylene glycol).
[0041] Specifically, the metal interdigital electrode material of the wide temperature range flexible temperature sensor is one or two of gold, platinum, copper, nickel, and chromium. The deposition method is vacuum evaporation, magnetron sputtering, electron beam evaporation, or physical vapor deposition. The thickness is 5-200nm. Interdigital electrodes with a line width and line spacing of 0.1mm are formed on the substrate surface through laser etching technology.
[0042] Specifically, molybdenum carbide semiconductor film material and sensitive layer material are deposited on the substrate by inkjet printing, and then two-dimensional transition metal carbide can be obtained by hydrogen reduction. Ammonium molybdate is first reduced to MoO2 at 450°C in an argon atmosphere, and then MoO2 and a carbon source are reduced under hydrogen. The reduction temperature range is 550-1050°C, and the ratio of argon to hydrogen is about 1:1.
[0043] Specifically, the sensitive layer material of the wide-temperature-range flexible temperature sensor is adjusted according to different M and X sources (MX, M = Mo, W, Ti, Zr; X = C, Si, Ge). Taking Mo and C as an example, ammonium molybdate tetrahydrate is selected as the Mo source, and polyvinyl alcohol (PVA) or glucose is selected as the carbon source.
[0044] The substrate of the wide temperature range flexible temperature sensor is one of mica, silicon wafer, glass, corundum and sapphire, and the thickness of the substrate is 0.01 to 2 mm.
[0045] Specifically, the sensitive layer material can obtain precursors of different purities by adjusting different ratios of molybdenum and carbon sources.
[0046] Molybdenum carbide semiconductor thin film material. If no carbon source is introduced during the synthesis of molybdenum carbide material, molybdenum (Mo) metal will be synthesized.
[0047] The material of the present invention is used to prepare a temperature sensor with a response range of 25 to 1500°C. The preparation method comprises applying conductive carbon oil or silver ink as an adhesive between an electrode and a test lead. After curing, a temperature sensor is obtained. A temperature sensor array is also prepared, comprising sensor elements, each of which is a square sensor with a side length of 1 to 10 mm.
[0048] The following describes in detail a method for preparing a wide temperature range, fast response temperature sensor through specific implementation methods.
[0049] Example 1:
[0050] Provided is a platinum interdigitated electrode / molybdenum carbide alloy temperature sensor deposited on a substrate, which is prepared by the following method:
[0051] (1) Preparation of platinum interdigitated electrodes:
[0052] Using mica as the substrate, a pre-designed patterned alloy mask was used to uniformly deposit Pt on the mica substrate through magnetron sputtering technology to obtain Pt interdigital electrodes with a thickness of about 300 mm and a line width and line spacing of 0.1 mm. The mica substrate with the Pt interdigital electrodes was then treated with UV ozone for 10 minutes. Figure 3 These are pictures and optical pictures of the platinum electrodes prepared in Examples 1 to 8.
[0053] (2) Preparation of Molybdenum Carbide Alloy Sensitive Layer:
[0054] First, a precursor solution containing a molybdenum source and a carbon source was prepared. 0.06 g of ammonium molybdate tetrahydrate and 1 ml of propylene glycol were dissolved in 3 ml of water with a Mo / C molar ratio of 10:1. 2 ml of ethanol was then added dropwise, and ultrasonic-assisted dissolution was used. The precursor ink was then deposited onto the surface of the Pt interdigitated electrode by inkjet printing. The deposited precursor was then annealed at 450°C for 30 minutes in a mixed gas atmosphere of hydrogen and argon in a ratio of 1:1, then heated to 750°C for 10 minutes and then kept at that temperature for 1 hour to obtain a molybdenum carbide alloy sensitive layer with a thickness of approximately 40 nm.
[0055] (3) Preparation of passivation layer:
[0056] By depositing 50nm thick aluminum oxide on the surface of the sensitive layer through atomic layer deposition, a molybdenum carbide alloy temperature sensor can be successfully prepared.
[0057] Examples 1 to 8 provide platinum interdigitated electrodes / molybdenum carbide alloy / passivation layer temperature sensors deposited on a substrate. Except for the conditions described in Table 1, the specific operating process is the same as that of Example 1. Figure 1 The physical shape comparison of the temperature sensor in the bent state and the normal state is shown.
[0058] Table 1 Experimental conditions of Examples 1 to 8:
[0059]
[0060] Furthermore, a conductive silver paste was used as an adhesive between the Pt interdigitated electrodes and the test wires. After the silver paste was cured, it was used for performance testing. The temperature sensors provided in Examples 1 to 6 were subjected to performance tests respectively.
[0061] ①Temperature response range:
[0062] Connect the test wires to a digital multimeter and gradually increase the temperature of the temperature sensor from 25°C to 1500°C. Use the digital multimeter to record the resistance change during the heating process and calculate the response temperature range of the temperature sensor.
[0063] ②Response time
[0064] A heater is attached to the surface of the temperature sensor and a certain voltage is applied to it, thereby generating temperature. This temperature is transmitted to the sensitive layer of the temperature sensor, causing the resistance of the temperature sensor to change. By analyzing the resistance change curve recorded by the digital multimeter over time, the response time can be calculated.
[0065] ③Detection resolution
[0066] The heating rate is precisely controlled, and the temperature sensor is gradually heated by 0.02°C and 0.05°C. A digital multimeter is used to record the resistance change. If a regular resistance change can be detected, it is considered that the detection resolution can be achieved.
[0067] The resistance change rate curve of Example 1 is as follows: Figure 2 As shown, it can be seen that as the temperature increases from 25°C to 1500°C, the resistance of the temperature sensor gradually decreases, indicating that the sensor is in a wide temperature range.
[0068] The resistance change rate of Experimental Example 1 is shown as follows: Figure 3 As shown, it can be seen that the resistance of the sensor changes by changing the temperature, and the response time is calculated to be about 0.18s, indicating that the sensor resistance has a transient response with temperature changes.
[0069] In Experimental Example 1-6, a platinum interdigitated electrode was prepared on the substrate surface using magnetron sputtering technology. The optical image is shown in FIG. Figure 4 As shown, the interdigitated structure is clearly displayed.
[0070] In Experimental Example 1-6, the precursor was deposited on the surface of the interdigitated electrode by inkjet printing, and the optical image thereof is shown as follows: Figure 5 As shown, the precursor is uniformly deposited on the surface of the platinum interdigitated electrode.
[0071] Figure 6 The XRD patterns of the annealed products of Experimental Examples 1-3 are shown, demonstrating the successful synthesis of Mo2C.
[0072] Figure 7 The XRD patterns of the annealed products of Experimental Examples 4-6 are shown, which also prove the successful synthesis of Mo2C.
[0073] The difference between Example 7 and Examples 1 to 6 is that no carbon source is added to the precursor solution configuration; the difference between Experimental Example 8 and Experimental Example 1 is that no hydrogen is introduced during the thermal annealing reduction process.
[0074] Figure 8 The XRD comparison of the products with and without the introduction of carbon source is shown in Figure 2. The results show that the addition of carbon source successfully prepared Mo2C thin film, while the final product of Experiment 7 was molybdenum metal (Mo).
[0075] Figure 9 1 is the XRD pattern of the product of thermal annealing in the absence of hydrogen in Experimental Example 8. The results show that the final product is molybdenum dioxide (MoO2).
[0076] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.
[0077] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.
Claims
1. A method for preparing a molybdenum carbide semiconductor film, characterized in that: The steps include: Step 1: After dissolving the molybdenum source and carbon source in water, add 1 / 3 volume of ethanol dropwise to prepare a precursor ink of molybdenum carbide material; the Mo / C molar ratio is 10:1; Step 2: Deposit the precursor ink of molybdenum carbide material on the surface of the substrate, and then keep it at 450°C under the condition of argon and hydrogen volume ratio of 1:1, and then raise the temperature to 550-1050°C for annealing to obtain molybdenum carbide semiconductor film.
2. The method for preparing a molybdenum carbide semiconductor film according to claim 1, wherein: In the step 2, specifically, the temperature is kept at 450° C. for 30 minutes, and then the temperature is raised to 550-1050° C. for 10 minutes and annealed for 1 hour.
3. The method for preparing a molybdenum carbide semiconductor film according to claim 2, wherein: In the step 2, the temperature is raised to 750° C. for annealing.
4. The method for preparing a molybdenum carbide semiconductor film according to claim 1, 2 or 3, characterized in that: The molybdenum source is ammonium molybdate, the carbon source is a carbon-containing solid or a carbon-containing solvent; the carbon-containing solid is polyvinyl alcohol or glucose, and the carbon-containing solvent is ethylene glycol, propylene glycol or butylene glycol.
5. The method for preparing a molybdenum carbide semiconductor film according to claim 1, 2 or 3, characterized in that: In the step 2, the precursor ink of the molybdenum carbide material is deposited on the substrate by inkjet printing, and then reduced by hydrogen to obtain a two-dimensional transition metal carbide.
6. The method for preparing a molybdenum carbide semiconductor film according to claim 5, characterized in that: Specifically, the ammonium molybdate is first reduced to MoO2 at 450°C in an argon atmosphere, and then MoO2 and a carbon source are reduced in hydrogen at a reduction temperature ranging from 550 to 1050°C.
7. The method for preparing a molybdenum carbide semiconductor film according to claim 1, 2 or 3, characterized in that: The substrate is one of mica, silicon wafer, glass, corundum and sapphire, and the thickness of the substrate is 0.01-2 mm.
8. A molybdenum carbide semiconductor film, characterized in that: The molybdenum carbide semiconductor film is prepared using the method for preparing the molybdenum carbide semiconductor film according to any one of claims 1 to 7.
9. Use of the molybdenum carbide semiconductor film according to claim 8 in preparing a flexible temperature sensor with a wide temperature range.
10. A flexible temperature sensor with a wide temperature range, characterized in that: The preparation method comprises: (1) Preparation of metal interdigitated electrodes on a substrate: (2) A molybdenum carbide semiconductor film is prepared as a sensitive layer on the metal interdigitated electrode using the method for preparing a molybdenum carbide semiconductor film according to any one of claims 1 to 7; (3) Aluminum oxide was deposited as a protective layer on the surface of the sensitive layer by atomic layer deposition to successfully prepare a molybdenum carbide alloy temperature sensor; The metal interdigital electrode material is at least one of gold, platinum, copper, nickel and chromium, and is deposited by vacuum evaporation, magnetron sputtering, electron beam evaporation or physical vapor deposition, with a thickness of 5 to 200 nm; Interdigitated electrodes with a line width and line spacing of 0.1 mm are formed on the substrate surface by laser etching technology.