Photonic crystal high-temperature infrared device with weak PTC effect and preparation method thereof

Abstract

The invention relates to a weak PTC effect photonic crystal high-temperature infrared device and a preparation method thereof, and belongs to the technical field of preparation of high-temperature infrared heating devices. On the basis of doped negative temperature coefficient semiconductors and vibration arrangement, silver powder and a negative temperature coefficient semiconductor material are arranged into a photonic crystal structure through the processes of mechanical dispersion, screen printing, mechanical vibration, high-temperature sintering and the like. The negative temperature coefficient semiconductor material is doped to form a shallow impurity energy level or a defect state, when the temperature rises, impurity ionization and intrinsic excitation cause the carrier concentration to be remarkably increased, the resistance is reduced, and the resistance fluctuation of a high-temperature device can be reduced through reasonable doping. The photonic crystal structure with the band gap of 3-8 microns can achieve mirror-like reflection of the infrared band, and a high-temperature device can obtain high infrared heating capacity. Through the process, the photonic crystal high-temperature infrared device with the weak PTC effect can be successfully obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-temperature infrared heating device preparation, and more specifically, relates to a weak PTC effect photonic crystal high-temperature infrared device and a preparation method thereof. Background Art

[0002] High-temperature electric heating technology (heating above 500°C) is safe, controllable, environmentally friendly and energy-saving. It is the main technical method for human society to achieve high-temperature conditions. It is widely used in household appliances, metallurgical forging, chemical catalysis, aerospace and other fields. Currently, common high-temperature heating products on the market mainly use electric heating tubes, ceramic heaters and induction heaters as heating devices. The electric heating tube is based on nickel-chromium alloy or iron-chromium-aluminum resistance wire, encapsulated in a metal sheath and magnesium oxide insulating medium. Its radiation spectrum shows a broad blackbody characteristic (3-8μm band accounts for less than 40%), the electric-to-thermal conversion efficiency is low, and high-temperature oxidation causes grain boundary embrittlement of the resistance wire, which will seriously affect the service life and cannot meet long-term industrial needs; although the ceramic heater has improved the infrared emissivity through the modification of barium titanate-based semiconductor ceramics, its significant PTC effect causes the resistivity to rise sharply by 3-4 orders of magnitude near the Curie temperature, causing power output instability, and the grain boundary diffusion in the high temperature zone is aggravated, and the resistance drift rate is high, which limits its application in precision temperature control scenarios; although the induction heater relies on the eddy current effect to achieve non-contact and efficient heating, its technical limitations are particularly prominent. The high-frequency power module is expensive and is only applicable to ferromagnetic materials (such as carbon steel). It is completely ineffective for non-metallic or low-magnetic permeability materials (such as ceramics and composite materials). At the same time, electromagnetic interference requires additional shielding, further increasing the system complexity and maintenance cost. The contradictions in energy efficiency, stability and applicability of the above-mentioned technical system urgently need to be broken through through material innovation and structural design.

[0003] It can be seen that the existing technology has technical problems such as significant PTC effect (excessive fluctuation of high-temperature resistance), low high-temperature infrared radiation energy and low heating efficiency. Summary of the Invention

[0004] In response to the above defects or improvement needs of the prior art, the present invention provides a weak PTC effect photonic crystal high-temperature infrared device and a preparation method thereof. The high-temperature infrared device of the present invention includes a heating element and conductive electrodes located at both ends of the heating element. The heating element is a photonic crystal formed by a periodic arrangement of silver powder and a negative temperature coefficient semiconductor material. The silver powder and negative temperature coefficient semiconductor material in the high-temperature infrared device of the present invention can generate a large amount of Joule heat, and the internal infrared photonic crystal structure efficiently reflects infrared rays in the 3-8μm band, thereby increasing the infrared energy emitted by the device and improving the overall heating efficiency. This solves the technical problems in the prior art of significant PTC effect (excessive fluctuations in high-temperature resistance), low high-temperature infrared radiation energy, and low heating efficiency.

[0005] According to a first aspect of the present invention, a photonic crystal high-temperature infrared device is provided, comprising a heating element and conductive electrodes located at both ends of the heating element, wherein the heating element is a photonic crystal formed by periodically arranging silver powder and a negative temperature coefficient semiconductor material.

[0006] Preferably, the negative temperature coefficient semiconductor material is selected from TiO2, NiO, SnO2, V2O5, AZO, ATO, Ga2O3 or TaN.

[0007] According to another aspect of the present invention, a method for preparing the photonic crystal high-temperature infrared device is provided, comprising the following steps:

[0008] (1) adding a dispersant, glass powder, silver powder, and a negative temperature coefficient semiconductor material to a polymer solution to obtain a slurry;

[0009] (2) The slurry obtained in step (1) is printed on an insulating substrate to form a film, and the film is formed after standing and leveling to obtain an initial heating layer. The initial heating layer is subjected to mechanical vibration. During the vibration process, the particles in the slurry are arranged in an orderly manner along the direction of the force, forming a heating layer with a photonic crystal structure; electrodes are printed on both ends of the heating layer and dried, and then an insulating slurry is printed on the heating layer and dried, and then sintered to melt the glass powder, thereby obtaining a photonic crystal high-temperature infrared device.

[0010] Preferably, in step (2), the sintering includes two stages. In the first stage, the temperature is raised to 300-400°C at 2-3.5°C / min and kept warm for 100-150 minutes to remove organic components; in the second stage, the temperature is raised to 700-850°C at 3-4.5°C / min and kept warm for 10-30 minutes to melt the glass powder.

[0011] Preferably, the mechanical vibration conditions are: amplitude 0.1 mm-2 mm, frequency 30 Hz-50 Hz, and time 20 min-40 min.

[0012] Preferably, in step (1), the dispersant is first added to the polymer solution, and then the glass powder, silver powder and negative temperature coefficient semiconductor material are added in sequence;

[0013] Preferably, the glass powder, silver powder and negative temperature coefficient semiconductor material are added multiple times, and the added amounts decrease gradually.

[0014] Preferably, the negative temperature coefficient semiconductor material is selected from TiO2, NiO, SnO2, V2O5, AZO, ATO, Ga2O3 or TaN; and the size of the negative temperature coefficient semiconductor material is 500nm-2500nm.

[0015] Preferably, the polymer solution is an aqueous polyurethane solution, an aqueous acrylic resin solution, an organic silicone resin solution, a terpineol solution of ethyl cellulose, or a polyvinyl chloride resin solution;

[0016] The silver powder is in the form of flakes, spheres or wires, and the particle size of the silver powder is 500nm-2500nm;

[0017] The glass powder is borosilicate glass, bismuth-based glass, aluminosilicate glass or phosphosilicate glass; and the particle size of the glass powder is 500-2000 meshes.

[0018] The dispersant is polyamide, polyimide, polyurethane, polyacrylate or amino acid ester copolymer;

[0019] The insulating substrate is microcrystalline glass, stainless steel, quartz glass, aluminum oxide or aluminum nitride.

[0020] Preferably, the mass ratio of the glass powder to the volume of the polymer solution is 0.3g / ml-0.6g / ml, the mass ratio of the silver powder to the volume of the polymer solution is 0.4g / ml-0.6g / ml, and the mass ratio of the negative temperature coefficient semiconductor material to the volume of the polymer solution is 0.3g / ml-0.6g / ml.

[0021] According to another aspect of the present invention, there is provided an application of the photonic crystal high-temperature infrared device for electrothermal heating;

[0022] Preferably, the temperature of the electric heating is 500°C-550°C.

[0023] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0024] (1) In the present invention, silver powder is the main conductive phase and is used to generate Joule heat. Negative temperature coefficient semiconductor materials are used to form photonic crystals in a periodic and orderly arrangement with silver powder, which also generates some heat. The photonic crystal structure has a regulatory effect on the propagation behavior of electromagnetic waves. It can exhibit mirror-like reflection within the photonic band gap range, and the photonic crystal structure with an infrared band photonic band gap can efficiently reflect infrared rays. When the high-temperature infrared device of the present invention is working, the silver powder and semiconductor materials can generate a large amount of Joule heat, and the internal infrared photonic crystal structure efficiently reflects infrared rays in the 3-8μm band, thereby increasing the infrared energy emitted by the device and improving the overall heating efficiency.

[0025] (2) The negative temperature coefficient semiconductor material of the present invention forms shallow impurity energy levels or defect states through doping. When the temperature rises, impurity ionization and intrinsic excitation lead to a significant increase in carrier concentration, which manifests as a decrease in resistance, reducing the resistance fluctuation of high-temperature devices. The photonic crystal structure with a band gap of 3-8μm can achieve mirror-like reflection in this infrared band, which can enable high-temperature devices to obtain strong infrared heating capabilities. Through the above process, a weak PTC effect photonic crystal high-temperature infrared device can be successfully obtained.

[0026] (3) The present invention incorporates negative temperature coefficient semiconductor materials into high-temperature infrared slurries. When high-temperature heating is performed, impurity ionization and intrinsic excitation lead to a significant increase in carrier concentration, which manifests as a decrease in resistance. Traditional high-temperature heating devices have a significant PTC effect, and the resistance increases rapidly with increasing temperature, which reduces the heating efficiency during high-temperature heating. At the same time, the resistance fluctuates greatly with temperature changes, limiting the scope of application. After doping with negative temperature coefficient semiconductor materials, high-temperature devices with weak PTC effects can be obtained, effectively reducing temperature fluctuations during high-temperature heating and improving heating efficiency.

[0027] (4) Adding silver powder, glass powder and negative temperature coefficient semiconductor material to the polymer solution at one time will lead to large-volume agglomeration and caking problems. Based on this, the present invention adds glass powder to the slurry in multiple times, and the amount of addition decreases gradually, so that the glass powder can be evenly dispersed in the slurry. Then, silver powder and negative temperature coefficient semiconductor material are added to the slurry in the same way, so that the glass powder, silver powder and negative temperature coefficient semiconductor material in the high-temperature infrared slurry can be evenly dispersed. If the amount added each time is the same, the dispersion effect will gradually deteriorate as the number of additions increases. However, in the present invention, the amount added decreases gradually, which can ensure that the dispersion effect is better each time.

[0028] (5) The glass powder of the present invention has a relatively high melting point and can provide bonding function at high temperatures; the polymer solution provides processing performance at room temperature; and the addition of an appropriate amount of dispersant improves the dispersion effect of the solid particles.

[0029] (6) The present invention uses screen printing and mechanical vibration to obtain a photonic crystal structure. During screen printing, the shear force provided by the scraper causes the solid particles to be initially arranged. After the slurry is allowed to settle and level, a mechanical vibration device is used to cause the micro-nano particles to move in a controlled manner at a specific frequency and amplitude. During the vibration process, the interaction force between the particles is fully adjusted, thereby causing the particles to align along a predetermined direction, ultimately forming a photonic crystal structure with long-range order. This photonic crystal processing method is simple and efficient, and is suitable for the large-scale, large-area manufacturing of weak PTC effect photonic crystal high-temperature infrared devices.

[0030] (7) The present invention uses a high-temperature gradient heating process to sinter the preliminary high-temperature infrared device at high temperature. First, slowly heat it to 300℃-400℃ and keep it warm for a period of time to completely remove the organic components in the coating and reduce internal defects. Then heat it to a temperature above the melting point of the glass powder and keep it warm for a short time (10min-30min) to allow the glass powder to fully melt and wet the solid components. After cooling and solidification, the connection of the components can be completed. If there is no medium or low temperature (first stage heating) insulation process, the organic matter will decompose quickly to produce micropores or cracks, resulting in reduced mechanical strength. If the high temperature insulation time is too long, it will cause oxidation of the silver powder and excessive coating of the glass powder, resulting in reduced conductivity of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of a weak PTC effect photonic crystal high-temperature infrared device provided by an embodiment of the present invention.

[0032] Figure 2 This is a scanning electron microscope image of the heating layer of the weak PTC effect photonic crystal high-temperature infrared device provided in Example 1 of the present invention.

[0033] Figure 3 1 is a temperature-resistance test result graph of the weak PTC effect photonic crystal high-temperature infrared device prepared according to Examples 1 and 2 of the present invention and the high-temperature heating device prepared according to Comparative Example 1.

[0034] Figure 4 This is a scanning electron microscope image of the heating layer of the weak PTC effect photonic crystal high-temperature infrared device provided in Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0036] Comparative Example 1

[0037] Purchase existing high-temperature heating paste (silver-palladium paste) that does not contain negative temperature coefficient semiconductor materials.

[0038] Take 2g of high-temperature heating slurry and place it on a 100-mesh screen printing screen. Use a scraper to print the high-temperature heating slurry on the microcrystalline glass at a certain rate. After standing for 2 minutes to level, put it in an 80°C oven and dry it for 20 minutes to obtain a heating layer. Print high-temperature electrodes at both ends of the heating layer and put it in an 80°C oven to dry for 20 minutes. Print insulating slurry on it and put it in an 80°C oven to dry for 20 minutes to obtain a preliminary high-temperature heating device. Put it into a muffle furnace and heat it to 900°C at a heating rate of 4.5°C / min. Keep it at this temperature for 20 minutes and cool it to room temperature with the furnace to obtain a high-temperature heating device.

[0039] Example 1

[0040] (1) 1000nm flake silver powder, 1000nm antimony tin oxide (ATO), 500 mesh aluminosilicate glass powder and 10% ethyl cellulose terpineol solution were selected as raw materials.

[0041] (2) Place 20 mL of ethyl cellulose and terpineol solution in a container and stir with a dispersing disk at a speed of 600 rpm. Under this stirring condition, first add 0.2 mL of dispersant and stir for 5 minutes to obtain a preliminary slurry. Add glass powder to the slurry in batches, 3 g for the first time, 2 g for the second time, 1 g for the third time, and 6 g in total. Stir for 20 minutes after each addition. Add flaky silver powder to the slurry in batches, 5 g for the first time, 3 g for the second time, 2 g for the third time, and 10 g in total. Stir for 20 minutes after each addition to obtain a high-temperature slurry. Add ATO powder to the high-temperature slurry in batches, 4 g for the first time, 3 g for the second time, 1 g for the third time, and 8 g in total. Stir for 20 minutes after each addition to obtain a high-temperature infrared slurry.

[0042] (3) Take 2g of high-temperature infrared slurry and place it on a 100-mesh screen printing screen. Use a scraper to print the high-temperature conductive slurry on the microcrystalline glass at a certain rate. Let it stand for 5 minutes to level it to obtain an initial heating layer. Fix the initial heating layer on a mechanical vibration device with a frequency of 30Hz and an amplitude of 0.1mm. Vibrate for 20 minutes and place it in an 80℃ oven to dry for 20 minutes to obtain a heating layer with a photonic crystal structure. Print high-temperature electrodes at both ends of the heating layer and place it in an 80℃ oven to dry for 20 minutes. Print insulating slurry on it and place it in an 80℃ oven to dry for 20 minutes to obtain a preliminary high-temperature infrared device.

[0043] (4) The sample was placed in a muffle furnace, first heated to 300°C at a heating rate of 2°C / min, kept at this temperature for 100 min, then heated to 750°C at a heating rate of 3°C / min, kept at this temperature for 15 min, and cooled to room temperature in the furnace to obtain a weak PTC effect photonic crystal high-temperature infrared device.

[0044] Figure 1 It is a structural schematic diagram of a weak PTC effect photonic crystal high-temperature infrared device provided by an embodiment of the present invention.

[0045] SEM image of the heating layer of the weak PTC effect photonic crystal high temperature infrared device prepared in Example 1 of the present invention (see Appendix Figure 2 ) shows that the micro-nanoparticles have reached a certain degree of order and have a photonic crystal structure.

[0046] Example 2

[0047] The steps of this embodiment are the same as those of embodiment 1, except that:

[0048] (1) 2000nm spherical silver powder, 1500nm V2O5, 1000 mesh borosilicate glass powder and aqueous acrylic resin solution were selected as raw materials.

[0049] (2) The amount of dispersant added is 0.4 mL. When adding glass powder to the slurry in batches, add 4 g for the first time, 3 g for the second time, and 1 g for the third time, for a total of 8 g. Stir for 15 minutes after each addition. Add flaky silver powder to the slurry in batches, add 6 g for the first time, 4 g for the second time, and 2 g for the third time, for a total of 12 g. Stir for 15 minutes after each addition to obtain a high-temperature slurry. Add V2O5 powder to the high-temperature slurry in batches, add 4 g for the first time, 3 g for the second time, and 2 g for the third time, for a total of 9 g. Stir for 15 minutes after each addition to obtain a high-temperature infrared slurry.

[0050] (3) The mechanical vibration frequency is 50 Hz, the amplitude is 0.2 mm, and the vibration time is 40 min.

[0051] (4) During high-temperature sintering, the temperature was first raised to 350°C at a heating rate of 3°C / min, and kept at this temperature for 120 minutes. The temperature was then raised to 800°C at a heating rate of 4°C / min, and kept at this temperature for 20 minutes.

[0052] In order to prove that the high-temperature infrared device of the present invention has a weak PTC effect (small fluctuation in high-temperature resistance), the resistance of Example 1, Example 2 and Comparative Example 1 at different temperatures are compared. At low temperatures (below 260°C), all three cases show a significant increase in resistance. As the temperature continues to rise, the increase in resistance of Example 1 and Example 2 becomes gentle. The Example gradually stabilizes at around 21Ω, with an increase of only 2.8Ω in the range of 260°C-550°C. The Example 2 gradually stabilizes at around 21Ω, with an increase of only 3.7Ω in the range of 260°C-550°C. The resistance of Comparative Example 1 shows a continuous upward trend, with an increase of 6.9Ω in the range of 260°C-550°C. The specific data are shown in Table 1 below, and the specific temperature-resistance curve is shown in the attached figure. Figure 3 shown.

[0053] Table 1

[0054] temperature Comparative Example 1 Example 1 Example 2 30℃ 11.2Ω 10.9Ω 10.5Ω 100℃ 14.6Ω 13.4Ω 13.2Ω 180℃ 17.6Ω 16.5Ω 15.9Ω 260℃ 20.4Ω 18.5Ω 17.8Ω 340℃ 23.7Ω 20.3Ω 20.1Ω 420℃ 24.9Ω 20.7Ω 20.9Ω 500℃ 26.4Ω 21.1Ω 21.4Ω 550℃ 27.3Ω 21.3Ω 21.5Ω

[0055] To demonstrate the low energy consumption advantage of the high-temperature infrared device of the present invention, the power required to reach 500°C in Example 1, Example 2, and Comparative Example 1 was compared. Example 1 required 419W less power than Comparative Example 1, resulting in an 18.1% reduction in energy consumption. Example 2 required 370W less power than Comparative Example 1, resulting in a 16.0% reduction in energy consumption. Specific data are shown in Table 2 below.

[0056] Table 2

[0057] Voltage (V) Current (A) Power (W) Comparative Example 1 247 9.36 2314 Example 1 200 9.48 1895 Example 2 204 9.53 1944

[0058] Example 3

[0059] The steps of this embodiment are the same as those of embodiment 1, except that:

[0060] (1) 2500nm linear silver powder, 500nm Ga2O3, 2000 mesh bismuth glass powder and silicone resin solution were selected as raw materials.

[0061] (2) When adding glass powder to the slurry in batches, add 5g for the first time, 4g for the second time, and 1g for the third time, for a total of 10g, and stir for 15 minutes after each addition. Add linear silver powder to the slurry in batches, 4g for the first time, 3g for the second time, and 2g for the third time, for a total of 9g, and stir for 15 minutes after each addition to obtain a high-temperature slurry. Add Ga2O3 powder to the high-temperature slurry in batches, 3g for the first time, 2g for the second time, and 1g for the third time, for a total of 6g, and stir for 15 minutes after each addition to obtain a high-temperature infrared slurry.

[0062] (3) The printing substrate is quartz glass, the static leveling time is 10 minutes, the mechanical vibration frequency is 50 Hz, the amplitude is 0.15 mm, and the vibration time is 30 minutes.

[0063] (4) During high-temperature sintering, the temperature was first raised to 350°C at a heating rate of 3.5°C / min, and kept at this temperature for 150 minutes. The temperature was then raised to 850°C at a heating rate of 4.5°C / min, and kept at this temperature for 30 minutes.

[0064] Example 4

[0065] The steps of this embodiment are the same as those of embodiment 1, except that:

[0066] (1) 500nm spherical silver powder, 2500nm zinc tin oxide (AZO), 1500mesh phosphosilicate glass powder and aqueous polyurethane solution were selected as raw materials.

[0067] (2) The amount of dispersant added is 0.6 mL. When adding glass powder to the slurry in batches, add 4 g for the first time, 3 g for the second time, and 2 g for the third time, for a total of 9 g. Stir for 15 minutes after each addition. Add flaky silver powder to the slurry in batches, add 5 g for the first time, 4 g for the second time, and 3 g for the third time, for a total of 12 g. Stir for 15 minutes after each addition to obtain a high-temperature slurry. Add AZO powder to the high-temperature slurry in batches, add 5 g for the first time, 4 g for the second time, and 3 g for the third time, for a total of 12 g. Stir for 15 minutes after each addition to obtain a high-temperature infrared slurry.

[0068] (3) The printing substrate is alumina, the static leveling time is 8 minutes, the mechanical vibration frequency is 50 Hz, the amplitude is 0.2 mm, and the vibration time is 25 minutes.

[0069] (4) During high-temperature sintering, the temperature was first raised to 380°C at a heating rate of 3°C / min, and kept at this temperature for 120 minutes. The temperature was then raised to 700°C at a heating rate of 3°C / min, and kept at this temperature for 10 minutes.

[0070] Example 5

[0071] The steps of this embodiment are the same as those of embodiment 1, except that:

[0072] (1) 2000nm flake silver powder, 2000nm NiO, 500 mesh aluminosilicate glass powder and polyvinyl chloride resin solution were selected as raw materials.

[0073] (2) The printing substrate is aluminum nitride, the static leveling time is 5 minutes, the mechanical vibration frequency is 40 Hz, the amplitude is 0.15 mm, and the vibration time is 30 minutes.

[0074] (3) During high-temperature sintering, the temperature was first increased to 350°C at a heating rate of 3°C / min, and kept at this temperature for 100 minutes. The temperature was then increased to 750°C at a heating rate of 3°C / min, and kept at this temperature for 15 minutes.

[0075] Example 6

[0076] The steps of this embodiment are the same as those of embodiment 1, except that:

[0077] (1) 1200nm linear silver powder, 1500nm TiO2, 1000 mesh borosilicate glass powder and 7% ethyl cellulose terpineol solution were selected as raw materials.

[0078] (2) The printing substrate is stainless steel (the surface has been insulated).

[0079] Comparative Example 2

[0080] The steps of this embodiment are the same as those of embodiment 1, except that:

[0081] (1) During high-temperature sintering, the temperature was first raised to 400°C at a heating rate of 3°C / min, and kept at this temperature for 120 minutes. The temperature was then raised to 800°C at a heating rate of 4°C / min, and kept at this temperature for 120 minutes.

[0082] The resistance of Comparative Example 2 at 30°C exceeds the multimeter's range (4MΩ), making it unusable as a high-temperature heating element. This is because the glass powder has good fluidity at 800°C and can fill the gaps between particles in a short time. Excessive holding time leads to excessive coating of the particles by the glass powder and oxidation of the silver powder, resulting in a decrease in the device's conductivity. Figure 4 This is a scanning electron microscope image of Comparative Example 2. The particles are basically covered with glass powder, and the direct contact between the particles is greatly reduced.

[0083] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A photonic crystal high-temperature infrared device, characterized in that: The device comprises a heating element and conductive electrodes located at both ends of the heating element. The heating element is a photonic crystal formed by periodically arranging silver powder and a negative temperature coefficient semiconductor material.

2. The photonic crystal high-temperature infrared device according to claim 1, characterized in that: The negative temperature coefficient semiconductor material is selected from TiO2, NiO, SnO2, V2O5, AZO, ATO, Ga2O3 or TaN.

3. The method for preparing a photonic crystal high-temperature infrared device according to claim 1 or 2, wherein: The following steps are involved: (1) adding a dispersant, glass powder, silver powder, and a negative temperature coefficient semiconductor material to a polymer solution to obtain a slurry; (2) The slurry obtained in step (1) is printed on an insulating substrate to form a film, and the film is formed after standing and leveling to obtain an initial heating layer. The initial heating layer is subjected to mechanical vibration. During the vibration process, the particles in the slurry are arranged in an orderly manner along the direction of the force, forming a heating layer with a photonic crystal structure; electrodes are printed on both ends of the heating layer and dried, and then an insulating slurry is printed on the heating layer and dried, and then sintered to melt the glass powder, thereby obtaining a photonic crystal high-temperature infrared device.

4. The method for preparing a photonic crystal high-temperature infrared device according to claim 3, wherein: In step (2), the sintering includes two stages. In the first stage, the temperature is raised to 300-400°C at 2-3.5°C / min and kept at this temperature for 100-150 minutes to remove organic components. In the second stage, the temperature is raised to 700-850°C at a rate of 3-4.5°C / min and kept at this temperature for 10-30 minutes to melt the glass powder.

5. The method for preparing a photonic crystal high-temperature infrared device according to claim 3, wherein: The mechanical vibration conditions are: amplitude 0.1 mm-2 mm, frequency 30 Hz-50 Hz, and time 20 min-40 min.

6. The method for preparing a photonic crystal high-temperature infrared device according to claim 3, wherein: In step (1), the dispersant is first added to the polymer solution, and then glass powder, silver powder and negative temperature coefficient semiconductor material are added in sequence; Preferably, the glass powder, silver powder and negative temperature coefficient semiconductor material are added multiple times, and the added amounts decrease gradually.

7. The method for preparing a photonic crystal high-temperature infrared device according to claim 3, wherein: The negative temperature coefficient semiconductor material is selected from TiO2, NiO, SnO2, V2O5, AZO, ATO, Ga2O3 or TaN; the size of the negative temperature coefficient semiconductor material is 500nm-2500nm.

8. The method for preparing a photonic crystal high-temperature infrared device according to claim 3, wherein: The polymer solution is an aqueous polyurethane solution, an aqueous acrylic resin solution, an organic silicone resin solution, a terpineol solution of ethyl cellulose or a polyvinyl chloride resin solution; The silver powder is in the form of flakes, spheres or wires, and the particle size of the silver powder is 500nm-2500nm; The glass powder is borosilicate glass, bismuth-based glass, aluminosilicate glass or phosphosilicate glass; and the particle size of the glass powder is 500-2000 mesh. The dispersant is polyamide, polyimide, polyurethane, polyacrylate or amino acid ester copolymer; The insulating substrate is microcrystalline glass, stainless steel, quartz glass, aluminum oxide or aluminum nitride.

9. The method for preparing a photonic crystal high-temperature infrared device according to claim 3, wherein: The mass ratio of the glass powder to the volume of the polymer solution is 0.3g / ml-0.6g / ml, the mass ratio of the silver powder to the volume of the polymer solution is 0.4g / ml-0.6g / ml, and the mass ratio of the negative temperature coefficient semiconductor material to the volume of the polymer solution is 0.3g / ml-0.6g / ml.

10. Application of the photonic crystal high-temperature infrared device according to claim 1 or 2 for electrothermal heating; Preferably, the temperature of the electric heating is 500°C-550°C.

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