A non-metallic intelligent thermal control device and its preparation method

Abstract

A non-metallic intelligent thermal control device and its fabrication method are disclosed, belonging to the field of passive radiative thermal management technology. The purpose of this invention is to solve the problems of limited processing technology, performance degradation of the metal layer, and compatibility with other layers caused by high-temperature softening of the metal layer in existing intelligent thermal control devices. The film structure of the non-metallic intelligent thermal control device, from bottom to top, consists of: an infrared reflective layer, a first transparent dielectric layer, a phase change material layer, a second transparent dielectric layer, a third transparent dielectric layer, a functional layer, and a fourth transparent dielectric layer; the infrared reflective layer is ITO; the first transparent dielectric layer is BaF2; the phase change material layer is a W-doped VO2 thin film; the second transparent dielectric layer is BaF2; the third transparent dielectric layer is ZnS; the functional layer is B4C; and the fourth transparent dielectric layer is ZnS. This invention has broad engineering application prospects, particularly showing great potential in building exterior walls, electronic device heat dissipation, and wearable devices.

Description

Technical Field

[0001] This invention belongs to the field of passive radiative thermal management technology, specifically relating to a non-metallic intelligent thermal control device and its preparation method. Background Technology

[0002] With the increasing severity of global climate change and the energy crisis, dynamic radiative thermal management technology, as an emerging thermal control method, is gradually becoming one of the key technologies for solving thermal management problems in buildings, electronic equipment, and other fields. This technology achieves precise control of surface temperature by utilizing the ability of materials to adjust their thermal radiation characteristics under different environmental conditions. Dynamic radiative thermal management technology can automatically adjust the thermal radiation performance of materials according to changes in external temperature, effectively avoiding overheating and significantly improving energy efficiency. This technology has shown great application potential, especially in building temperature control, electronic equipment heat dissipation, and wearable devices.

[0003] Radiation thermal management devices typically rely on a combination of a metallic reflective layer, a phase-change functional layer, and an infrared-transmitting layer. For example, Gu et al. proposed a smart thermal control device based on a Fabry-Perot cavity structure (VO2 / HfO2 / Al) with an emissivity variation of 0.51 (J.Gu,H.Wei,F.Ren,H.Guan,S.Liang,C.Geng,L.Li,J.Zhao,S.Dou,Y.Li,ACSAppl.Mater.Interfaces,2022,14,2683-2690). Taylor et al. fabricated a VO2 / Si / Al smart emitter based on a Fabry-Perot cavity, increasing its emissivity (2.5-25 μm) from 0.14 at room temperature to 0.60 at 100 °C. (S. Taylor, L. Long, R. McBurney, P. Sabbaghi, J. Chao, L. Wang, Sol. Energy Mater. Sol. Cells, 2020, 217, 110739).

[0004] However, in the film structure of intelligent thermal control devices, the metal layer typically achieves the design goal of low temperature and low emission through its high reflectivity, but this structure also has some significant drawbacks. The metal layer not only limits the flexibility of the processing technology but may also lead to poor stability of the film system, especially under high-temperature conditions, potentially challenging the overall structure's high-temperature resistance. For example, Al films cannot maintain long-term stability at temperatures as high as 500°C; therefore, when an Al film is present, the deposition and annealing temperature of the VO2 functional layer must not exceed 500°C. The metal reflective layer also limits the material's thermal radiation regulation performance under different environmental conditions, particularly the melting and softening that occurs under extreme temperature fluctuations, which may lead to a decrease in thermal control efficiency.

[0005] Furthermore, metal layers typically have a large coefficient of thermal expansion, which is incompatible with other non-metallic layers in the film system, affecting the long-term stability of the device during thermal cycling. Therefore, developing high-performance all-non-metallic intelligent thermal control devices to overcome the limitations imposed by metal layers is crucial for improving the application effect of dynamic radiative thermal management technology. Summary of the Invention

[0006] The purpose of this invention is to solve the problems of limited processing technology, degradation of metal layer performance, and compatibility with other layers caused by high-temperature softening of the metal layer in existing intelligent thermal control devices, and to provide a non-metallic intelligent thermal control device and its preparation method.

[0007] This invention proposes a non-metallic intelligent thermal control device, aiming to optimize the processing technology of intelligent thermal control devices to overcome performance bottlenecks and solve the compatibility problem between the metal layer and other functional layers to improve service stability.

[0008] The film structure of a non-metallic intelligent thermal control device, from bottom to top, consists of: an infrared reflective layer, a first transparent dielectric layer, a phase change material layer, a second transparent dielectric layer, a third transparent dielectric layer, a functional layer, and a fourth transparent dielectric layer.

[0009] The infrared reflective layer is ITO;

[0010] The first transparent dielectric layer is BaF2;

[0011] The phase change material layer is a W-doped VO2 thin film;

[0012] The second transparent dielectric layer is BaF2;

[0013] The third transparent dielectric layer is ZnS;

[0014] The aforementioned functional layer is B4C;

[0015] The fourth transparent dielectric layer is ZnS.

[0016] A method for fabricating a non-metallic intelligent thermal control device is specifically carried out according to the following steps:

[0017] I. Cleaning the substrate:

[0018] The substrate was ultrasonically cleaned in deionized water, anhydrous ethanol and acetone in sequence for a period of time, and then dried with nitrogen to obtain a clean substrate.

[0019] II. Preparation of the infrared reflective layer:

[0020] With a background vacuum of 10 -3 Pa~10 -5Under the conditions of Pa, temperature of 200℃~300℃, argon flow rate of 70sccm~100sccm, oxygen flow rate of 7sccm~10sccm, gas pressure of 0.4Pa~0.9Pa, and sputtering power of 150W~180W, an ITO thin film was deposited on a substrate using a conductive indium tin alloy as the target material and DC sputtering technology. The substrate was then annealed for a period of time in a nitrogen atmosphere at a temperature of 400℃~500℃ to obtain a substrate containing an infrared reflective layer.

[0021] III. Preparation of the first transparent dielectric layer:

[0022] With a background vacuum of 10 -6 Pa~10 -8 Pa, substrate temperature: room temperature to 100℃, target power: 2kW to 5kW, deposition rate: Under certain conditions, using BaF2 powder as the evaporation material, BaF2 thin film was deposited on the infrared reflective layer by electron beam evaporation technology to obtain a substrate containing a first transparent dielectric layer.

[0023] IV. Preparation of Phase Change Material Layer:

[0024] The frequency was 400Hz–450Hz, the pulse width was 50μs–100μs, the power was 180W–200W, and the background vacuum was 5×10⁻⁶. -4 Pa ~ 1×10 -5 Under the conditions of Pa, deposition pressure of 0.4 Pa to 0.9 Pa, argon flow rate of 80 sccm to 100 sccm, oxygen flow rate of 1.0 sccm to 1.5 sccm, and substrate temperature of 200℃ to 400℃, a W-doped VO2 thin film was deposited on the first transparent dielectric layer using a tungsten-vanadium alloy as the target material and high-energy pulsed magnetron sputtering technology. Then, the substrate was annealed for a period of time in an argon atmosphere at a temperature of 480℃ to 580℃ to obtain a substrate containing a phase change material layer.

[0025] V. Preparation of the second transparent dielectric layer:

[0026] With a background vacuum of 10 -6 Pa~10 -8 Pa, substrate temperature: room temperature to 100℃, target power: 2kW to 5kW, deposition rate: Under certain conditions, using BaF2 powder as the evaporation material, BaF2 thin film was deposited on the phase change material layer by electron beam evaporation technology to obtain a substrate containing a second transparent dielectric layer.

[0027] VI. Preparation of the third transparent dielectric layer:

[0028] With a background vacuum of 10 -6 Pa~10 -8Pa, substrate temperature: room temperature to 150℃, target power: 2kW to 4kW, deposition rate: Under certain conditions, ZnS powder was used as the evaporation material, and ZnS thin film was deposited on the second transparent dielectric layer by electron beam evaporation technology to obtain a substrate containing a third transparent dielectric layer.

[0029] VII. Fabrication of Functional Layers:

[0030] With a background vacuum of 10 -6 Pa~10 -8 Pa, substrate temperature: room temperature to 150℃, target power: 2kW to 4kW, deposition rate: Under certain conditions, using B4C powder as the evaporation material, B4C thin films were deposited on the third transparent dielectric layer by electron beam evaporation technology to obtain a substrate containing a functional layer.

[0031] 8. Preparation of the fourth transparent dielectric layer:

[0032] With a background vacuum of 10 -6 Pa~10 -8 Pa, substrate temperature: room temperature to 150℃, target power: 2kW to 4kW, deposition rate: Under certain conditions, ZnS powder was used as the evaporation material, and ZnS thin film was deposited on the functional layer using electron beam evaporation technology to obtain a non-metallic intelligent thermal control device.

[0033] The principle of this invention:

[0034] The functions of each layer in the non-metallic intelligent thermal control device described in this invention are as follows:

[0035] ITO layer: The application of ITO layer not only avoids the use of metal layer, but also enhances the compatibility of film system and reduces thermal stress between film layers during hot and cold cycles because its coefficient of thermal expansion is similar to that of other non-metallic materials.

[0036] BaF2 and ZnS layers: As a transparent medium material with high transmittance, BaF2 and ZnS layers can effectively transmit infrared light in radiative heat management.

[0037] VO2 layer: As a phase change material, VO2 exhibits significant temperature response characteristics, undergoing a metal-to-insulator phase transition upon temperature change, thereby altering its emissivity. The addition of VO2 enables the film system to dynamically regulate thermal radiation, automatically adjusting its thermal radiation capacity according to changes in ambient temperature, achieving precise thermal control.

[0038] B4C layer: The B4C layer, as a functional layer, provides additional optical properties. Together with the dielectric layer above, it modulates the spectrum to broaden the full width at half maximum (FWHM) and also enhances the structural stability and heat resistance of the film system.

[0039] The beneficial effects of this invention are:

[0040] I. This invention, through the design of this non-metallic intelligent thermal control device, successfully reduces the limitations of the metal reflective layer on the device's processing technology, avoiding performance degradation and poor compatibility with other layers. Through precise process design and post-annealing, the excellent stability of the lower layer material broadens the processing window for the upper layer, enabling the fabrication of phase change layers and functional layers with higher crystallinity at higher deposition and annealing temperatures. This improvement significantly enhances the device's thermal management capabilities and service stability, with an infrared emissivity change value (2.5-25μm) of 0.54, a high-temperature stability test result of 0.55, and a low-temperature stability test result of 0.53. Performance remains essentially unchanged after both high and low temperature stability tests.

[0041] II. The non-metallic intelligent thermal control device of the present invention avoids the use of traditional metal layers and adopts a combination of non-metallic infrared reflectors, transparent dielectric layers and phase change materials to achieve efficient and stable dynamic radiative heat management.

[0042] Third, this invention has broad engineering application prospects, especially showing great potential in the fields of building exterior walls, electronic device heat dissipation, and wearable devices. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the structure of the non-metallic intelligent thermal control device described in this invention;

[0044] Figure 2 The infrared reflectance spectrum of the non-metallic intelligent thermal control device prepared in Example 1 before high and low temperature stability testing;

[0045] Figure 3 The high-temperature stability test results of the non-metallic intelligent thermal control device prepared in Example 1 show the temperature-dependent infrared reflectance spectrum of the device.

[0046] Figure 4 The infrared reflectance spectrum of the non-metallic intelligent thermal control device prepared in Example 1 after low-temperature stability test. Detailed Implementation

[0047] Specific Implementation Method 1: The film structure of a non-metallic intelligent thermal control device, from bottom to top, consists of: an infrared reflective layer, a first transparent dielectric layer, a phase change material layer, a second transparent dielectric layer, a third transparent dielectric layer, a functional layer, and a fourth transparent dielectric layer;

[0048] The infrared reflective layer is ITO;

[0049] The first transparent dielectric layer is BaF2;

[0050] The phase change material layer is a W-doped VO2 thin film;

[0051] The second transparent dielectric layer is BaF2;

[0052] The third transparent dielectric layer is ZnS;

[0053] The aforementioned functional layer is B4C;

[0054] The fourth transparent dielectric layer is ZnS.

[0055] This invention improves the thermal stability and optical performance of thin film structures by selecting appropriate materials (ITO, BaF2, VO2, ZnS, B4C) and rationally arranging the deposition sequence of each layer. By combining electron beam evaporation and magnetron sputtering technologies, high-quality deposition of ITO, BaF2, VO2, ZnS, and B4C thin films has been successfully achieved. Precise control of the fabrication process of each thin film layer ensures the uniformity and quality of each layer, avoiding performance degradation issues in practical applications.

[0056] This invention solves the problems of metal layer processing limitations, performance degradation, and poor interlayer compatibility by using a non-metallic film structure that removes the metal layer. The excellent stability of the lower layer expands the process window of the upper layer, allowing the preparation of higher quality phase change layers at higher temperatures. This breaks through the performance bottleneck of traditional metal layer structures and improves thermal management capabilities and service stability.

[0057] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the thickness of the infrared reflective layer is 1200nm to 1300nm. The other steps are the same as in Specific Implementation Method One.

[0058] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that the thickness of the first transparent dielectric layer is 800nm ​​to 900nm. The other steps are the same as in Specific Implementation Method One or Two.

[0059] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the thickness of the phase change material layer is 40nm to 50nm. The other steps are the same as in Specific Implementation Methods One to Three.

[0060] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the thickness of the second transparent dielectric layer is 300nm to 400nm. The other steps are the same as in Specific Implementation Methods One to Four.

[0061] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that the thickness of the third transparent dielectric layer is 50nm to 60nm. The other steps are the same as in Specific Implementation Methods One to Five.

[0062] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the thickness of the functional layer is 300nm to 400nm. The other steps are the same as in Specific Implementation Methods One to Six.

[0063] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that the thickness of the fourth transparent dielectric layer is 110nm to 120nm. The other steps are the same as in Specific Implementation Methods One to Seven.

[0064] Specific Implementation Method Nine: This implementation method is a preparation method for a non-metallic intelligent thermal control device, specifically completed according to the following steps:

[0065] I. Cleaning the substrate:

[0066] The substrate was ultrasonically cleaned in deionized water, anhydrous ethanol and acetone in sequence for a period of time, and then dried with nitrogen to obtain a clean substrate.

[0067] II. Preparation of the infrared reflective layer:

[0068] With a background vacuum of 10 -3 Pa~10 -5 Under the conditions of Pa, temperature of 200℃~300℃, argon flow rate of 70sccm~100sccm, oxygen flow rate of 7sccm~10sccm, gas pressure of 0.4Pa~0.9Pa, and sputtering power of 150W~180W, an ITO thin film was deposited on a substrate using a conductive indium tin alloy as the target material and DC sputtering technology. The substrate was then annealed for a period of time in a nitrogen atmosphere at a temperature of 400℃~500℃ to obtain a substrate containing an infrared reflective layer.

[0069] III. Preparation of the first transparent dielectric layer:

[0070] With a background vacuum of 10 -6 Pa~10 -8 Pa, substrate temperature: room temperature to 100℃, target power: 2kW to 5kW, deposition rate: Under certain conditions, using BaF2 powder as the evaporation material, BaF2 thin film was deposited on the infrared reflective layer by electron beam evaporation technology to obtain a substrate containing a first transparent dielectric layer.

[0071] IV. Preparation of Phase Change Material Layer:

[0072] The frequency was 400Hz–450Hz, the pulse width was 50μs–100μs, the power was 180W–200W, and the background vacuum was 5×10⁻⁶. -4 Pa ~ 1×10 -5 Under the conditions of Pa, deposition pressure of 0.4 Pa to 0.9 Pa, argon flow rate of 80 sccm to 100 sccm, oxygen flow rate of 1.0 sccm to 1.5 sccm, and substrate temperature of 200℃ to 400℃, a W-doped VO2 thin film was deposited on the first transparent dielectric layer using a tungsten-vanadium alloy as the target material and high-energy pulsed magnetron sputtering technology. Then, the substrate was annealed for a period of time in an argon atmosphere at a temperature of 480℃ to 580℃ to obtain a substrate containing a phase change material layer.

[0073] V. Preparation of the second transparent dielectric layer:

[0074] With a background vacuum of 10 -6 Pa~10 -8 Pa, substrate temperature: room temperature to 100℃, target power: 2kW to 5kW, deposition rate: Under certain conditions, using BaF2 powder as the evaporation material, BaF2 thin film was deposited on the phase change material layer by electron beam evaporation technology to obtain a substrate containing a second transparent dielectric layer.

[0075] VI. Preparation of the third transparent dielectric layer:

[0076] With a background vacuum of 10 -6 Pa~10 -8 Pa, substrate temperature: room temperature to 150℃, target power: 2kW to 4kW, deposition rate: Under certain conditions, ZnS powder was used as the evaporation material, and ZnS thin film was deposited on the second transparent dielectric layer by electron beam evaporation technology to obtain a substrate containing a third transparent dielectric layer.

[0077] VII. Fabrication of Functional Layers:

[0078] With a background vacuum of 10 -6 Pa~10 -8 Pa, substrate temperature: room temperature to 150℃, target power: 2kW to 4kW, deposition rate: Under certain conditions, using B4C powder as the evaporation material, B4C thin films were deposited on the third transparent dielectric layer by electron beam evaporation technology to obtain a substrate containing a functional layer.

[0079] 8. Preparation of the fourth transparent dielectric layer:

[0080] With a background vacuum of 10 -6 Pa~10 -8Pa, substrate temperature: room temperature to 150℃, target power: 2kW to 4kW, deposition rate: Under certain conditions, ZnS powder was used as the evaporation material, and ZnS thin film was deposited on the functional layer using electron beam evaporation technology to obtain a non-metallic intelligent thermal control device.

[0081] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods One to Nine in the following ways: the substrate in Step One is quartz; in Step One, the substrate is sequentially ultrasonically cleaned in deionized water, anhydrous ethanol, and acetone for 20-30 minutes each; the annealing time in Step Two is 1-3 hours; the annealing time in Step Four is 2-6 hours; and the atomic fraction of tungsten in the tungsten-vanadium alloy in Step Four is 2%. Other steps are the same as in Specific Implementation Methods One to Nine.

[0082] The beneficial effects of the present invention are verified using the following embodiments:

[0083] Example 1: The film structure of a non-metallic intelligent thermal control device, from bottom to top, consists of: an infrared reflective layer, a first transparent dielectric layer, a phase change material layer, a second transparent dielectric layer, a third transparent dielectric layer, a functional layer, and a fourth transparent dielectric layer;

[0084] The infrared reflective layer is ITO with a thickness of 1285 nm;

[0085] The first transparent dielectric layer is BaF2 with a thickness of 872 nm;

[0086] The phase change material layer is a W-doped VO2 thin film with a thickness of 47 nm;

[0087] The second transparent dielectric layer is BaF2 with a thickness of 364 nm;

[0088] The third transparent dielectric layer is ZnS with a thickness of 51 nm;

[0089] The functional layer is B4C with a thickness of 389nm;

[0090] The fourth transparent dielectric layer is ZnS with a thickness of 113 nm;

[0091] The fabrication method of the non-metallic intelligent thermal control device is specifically completed according to the following steps:

[0092] I. Cleaning the substrate:

[0093] The substrate was ultrasonically cleaned in deionized water, anhydrous ethanol and acetone for 20 minutes each, and then dried with nitrogen to obtain a clean substrate.

[0094] The substrate mentioned in step one is quartz;

[0095] II. Preparation of the infrared reflective layer:

[0096] With a background vacuum of 1×10 -5 Under the conditions of Pa, temperature of 300℃, argon flow rate of 80sccm, oxygen flow rate of 8sccm, gas pressure of 0.9Pa and sputtering power of 150W, ITO thin film was deposited on the substrate using DC sputtering technology with conductive indium tin alloy as target material. Then, the substrate containing an infrared reflective layer was obtained by annealing in a nitrogen atmosphere at 400℃ for a period of time.

[0097] The annealing time mentioned in step two is 2 hours;

[0098] III. Preparation of the first transparent dielectric layer:

[0099] With a background vacuum of 1×10 -6 Pa, substrate temperature is room temperature, target power is 2kW, deposition rate is Under certain conditions, using BaF2 powder as the evaporation material, BaF2 thin film was deposited on the infrared reflective layer by electron beam evaporation technology to obtain a substrate containing a first transparent dielectric layer.

[0100] IV. Preparation of Phase Change Material Layer:

[0101] At a frequency of 400Hz, a pulse width of 70μs, a power of 180W, and a background vacuum of 5×10⁻⁶, -4 Under the conditions of Pa, deposition pressure of 0.4 Pa, argon flow rate of 80 sccm, oxygen flow rate of 1.5 sccm and substrate temperature of 200℃, a W-doped VO2 thin film was deposited on the first transparent dielectric layer using tungsten-vanadium alloy as the target material and high-energy pulsed magnetron sputtering technology. The film was then annealed for a period of time in an argon atmosphere at a temperature of 500℃ to obtain a substrate containing a phase change material layer.

[0102] The annealing time mentioned in step four is 6 hours;

[0103] The atomic fraction of tungsten in the tungsten-vanadium alloy described in step four is 2%.

[0104] V. Preparation of the second transparent dielectric layer:

[0105] With a background vacuum of 1×10 -6 Pa, substrate temperature is room temperature, target power is 2kW, deposition rate is Under certain conditions, using BaF2 powder as the evaporation material, BaF2 thin film was deposited on the phase change material layer by electron beam evaporation technology to obtain a substrate containing a second transparent dielectric layer.

[0106] VI. Preparation of the third transparent dielectric layer:

[0107] With a background vacuum of 1×10 -6 Pa, substrate temperature is room temperature, target power is 2kW, deposition rate is Under certain conditions, ZnS powder was used as the evaporation material, and ZnS thin film was deposited on the second transparent dielectric layer by electron beam evaporation technology to obtain a substrate containing a third transparent dielectric layer.

[0108] VII. Fabrication of Functional Layers:

[0109] With a background vacuum of 1×10 -6 Pa, substrate temperature 150℃, target power 4kW, deposition rate Under certain conditions, using B4C powder as the evaporation material, B4C thin films were deposited on the third transparent dielectric layer by electron beam evaporation technology to obtain a substrate containing a functional layer.

[0110] 8. Preparation of the fourth transparent dielectric layer:

[0111] With a background vacuum of 1×10 -6 Pa, substrate temperature is room temperature, target power is 2kW, deposition rate is Under certain conditions, ZnS powder was used as the evaporation material, and ZnS thin film was deposited on the functional layer using electron beam evaporation technology to obtain a non-metallic intelligent thermal control device.

[0112] The sample temperature was regulated using a self-made temperature control device with heating and cooling modes. Based on repeated measurements, the sample temperature error was less than 0.5℃. The temperature was measured by a thermocouple in contact with the regulator. During testing, the device temperature was controlled at 0℃ and 60℃ respectively. The infrared reflectance spectrum was measured using an A562 integrating sphere and a Vertex 70 Fourier transform infrared spectrometer.

[0113] According to Kirchhoff's laws, infrared emissivity can be calculated from the reflectance spectrum using the following two equations:

[0114]

[0115] Where c1 represents the first radiation constant, c2 represents the second radiation constant, λ represents the wavelength, and T represents the temperature. The emissivity variation is the difference between the emissivity at high and low temperatures.

[0116] Figure 2 The infrared reflectance spectrum of the non-metallic intelligent thermal control device prepared in Example 1 before high and low temperature stability testing;

[0117] from Figure 2 It can be seen that the emissivity change value of the non-metallic intelligent thermal control device prepared in Example 1 is 0.54.

[0118] The device was subjected to a high-temperature treatment at 500°C in a tube furnace for 1 hour under an argon atmosphere. The spectrum of the device was then measured again, and the emissivity was calculated. The conditions for spectral testing and emissivity calculation were the same as above.

[0119] Figure 3 The high-temperature stability test results of the non-metallic intelligent thermal control device prepared in Example 1 show the temperature-dependent infrared reflectance spectrum of the device.

[0120] from Figure 3 It can be seen that the emissivity change value of the non-metallic intelligent thermal control device prepared in Example 1 after the high temperature stability test is 0.55.

[0121] The device was immersed in liquid nitrogen for 1 hour for cryogenic treatment, and the spectrum of the device was measured again and the emissivity was calculated. The conditions for spectral testing and emissivity calculation were the same as above.

[0122] Figure 4 The temperature-varying infrared reflectance spectrum of the non-metallic intelligent thermal control device prepared in Example 1 after a low-temperature stability test;

[0123] from Figure 4 It can be seen that after the low-temperature stability test, the emissivity change value of the non-metallic intelligent thermal control device prepared in Example 1 is 0.53.

[0124] Example 2: The difference between this example and Example 1 is that the infrared reflective layer is ITO with a thickness of 1371 nm;

[0125] The first transparent dielectric layer is BaF2 with a thickness of 929 nm;

[0126] The phase change material layer is a W-doped VO2 thin film with a thickness of 50 nm;

[0127] The second transparent dielectric layer is BaF2 with a thickness of 342 nm;

[0128] The third transparent dielectric layer is ZnS with a thickness of 49 nm;

[0129] The functional layer is B4C with a thickness of 405nm;

[0130] The fourth transparent dielectric layer is ZnS with a thickness of 287 nm. All other steps and parameters are the same as in Example 1.

[0131] The infrared emissivity variation value (2.5-25μm) of the non-metallic intelligent thermal control device prepared in Example 2 reached 0.49. The emissivity variation value was 0.49 after the high temperature stability test and 0.48 after the low temperature stability test.

Claims

1. A method for preparing a non-metallic intelligent thermal control device, characterized in that... The non-metallic intelligent thermal control device has a film structure from bottom to top as follows: infrared reflective layer, first transparent dielectric layer, phase change material layer, second transparent dielectric layer, third transparent dielectric layer, functional layer, and fourth transparent dielectric layer; The infrared reflective layer is ITO; The first transparent dielectric layer is BaF2; The phase change material layer is a W-doped VO2 thin film; The second transparent dielectric layer is BaF2; The third transparent dielectric layer is ZnS; The aforementioned functional layer is B4C; The fourth transparent dielectric layer is ZnS; The preparation method of the aforementioned non-metallic intelligent thermal control device is specifically completed according to the following steps: I. Cleaning the substrate: The substrate was placed in deionized water, anhydrous ethanol and acetone in turn for ultrasonic cleaning for a period of time, and then dried with nitrogen to obtain a clean substrate. II. Preparation of the infrared reflective layer: With a background vacuum of 10 -3 Pa~10 -5 Under the conditions of Pa, temperature of 200℃~300℃, argon flow rate of 70sccm~100sccm, oxygen flow rate of 7sccm~10sccm, gas pressure of 0.4Pa~0.9Pa, and sputtering power of 150W~180W, an ITO thin film was deposited on a substrate using a conductive indium tin alloy as the target material and DC sputtering technology. The substrate was then annealed for a period of time in a nitrogen atmosphere at a temperature of 400℃~500℃ to obtain a substrate containing an infrared reflective layer. III. Preparation of the first transparent dielectric layer: With a background vacuum of 10 -6 Pa~10 -8 Under the conditions of Pa, substrate temperature of room temperature to 100℃, target power of 2kW to 5kW, and deposition rate of 1Å / s to 3Å / s, BaF2 powder was used as the evaporation material, and BaF2 thin film was deposited on the infrared reflective layer by electron beam evaporation technology to obtain a substrate containing a first transparent dielectric layer. IV. Preparation of Phase Change Material Layer: The frequency was 400Hz~450Hz, the pulse width was 50μs~100μs, the power was 180W~200W, and the background vacuum was 5×10⁻⁶. -4 Pa ~ 1×10 -5 Under the conditions of Pa, deposition pressure of 0.4Pa~0.9Pa, argon flow rate of 80sccm~100sccm, oxygen flow rate of 1.0sccm~1.5sccm, and substrate temperature of 200℃~400℃, a W-doped VO2 thin film was deposited on the first transparent dielectric layer using tungsten-vanadium alloy as the target material and high-energy pulsed magnetron sputtering technology. Then, it was annealed for a period of time in an argon atmosphere at a temperature of 480℃~580℃ to obtain a substrate containing a phase change material layer. V. Preparation of the second transparent dielectric layer: With a background vacuum of 10 -6 Pa~10 -8 Under the conditions of Pa, substrate temperature of room temperature to 100℃, target power of 2kW to 5kW, and deposition rate of 1Å / s to 3Å / s, BaF2 powder was used as the evaporation material, and BaF2 thin film was deposited on the phase change material layer by electron beam evaporation technology to obtain a substrate containing a second transparent dielectric layer. VI. Preparation of the third transparent dielectric layer: With a background vacuum of 10 -6 Pa~10 -8 Under the conditions of Pa, substrate temperature of room temperature to 150℃, target power of 2kW to 4kW, and deposition rate of 1Å / s to 3Å / s, ZnS powder was used as the evaporation material, and ZnS thin film was deposited on the second transparent dielectric layer by electron beam evaporation technology to obtain a substrate containing a third transparent dielectric layer. VII. Fabrication of Functional Layers: With a background vacuum of 10 -6 Pa~10 -8 Under the conditions of Pa, substrate temperature of room temperature to 150℃, target power of 2kW to 4kW, and deposition rate of 0.5Å / s to 1.5Å / s, B4C powder was used as the evaporation material, and B4C thin film was deposited on the third transparent dielectric layer by electron beam evaporation technology to obtain a substrate containing a functional layer.

8. Preparation of the fourth transparent dielectric layer: With a background vacuum of 10 -6 Pa~10 -8 Under the conditions of Pa, substrate temperature of room temperature to 150℃, target power of 2kW to 4kW, and deposition rate of 1Å / s to 3Å / s, ZnS powder was used as the evaporation material, and ZnS thin film was deposited on the functional layer by electron beam evaporation technology to obtain a non-metallic intelligent thermal control device.

2. The method for preparing a non-metallic intelligent thermal control device according to claim 1, characterized in that... The thickness of the infrared reflective layer is 1200nm~1300nm.

3. The method for preparing a non-metallic intelligent thermal control device according to claim 1, characterized in that... The thickness of the first transparent dielectric layer is 800nm~900nm.

4. The method for preparing a non-metallic intelligent thermal control device according to claim 1, characterized in that... The thickness of the phase change material layer is 40nm~50nm.

5. The method for preparing a non-metallic intelligent thermal control device according to claim 1, characterized in that... The thickness of the second transparent dielectric layer is 300nm~400nm.

6. The method for preparing a non-metallic intelligent thermal control device according to claim 1, characterized in that... The thickness of the third transparent dielectric layer is 50nm~60nm.

7. The method for preparing a non-metallic intelligent thermal control device according to claim 1, characterized in that... The thickness of the functional layer is 300nm~400nm.

8. The method for preparing a non-metallic intelligent thermal control device according to claim 1, characterized in that... The thickness of the fourth transparent dielectric layer is 110nm~120nm.

9. The method for preparing a non-metallic intelligent thermal control device according to claim 1, characterized in that... The substrate mentioned in step one is quartz; in step one, the substrate is ultrasonically cleaned in deionized water, anhydrous ethanol and acetone for 20 min to 30 min respectively; the annealing time mentioned in step two is 1 h to 3 h; the annealing time mentioned in step four is 2 h to 6 h; the atomic fraction of tungsten in the tungsten-vanadium alloy mentioned in step four is 2%.

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