Vanadium dioxide-based symmetrical sandwich structure thermal control thin film with high spatial stability and low phase transition temperature and preparation method of vanadium dioxide-based symmetrical sandwich structure thermal control thin film

Abstract

The invention discloses a vanadium dioxide-based sandwich structure thermal control film with high spatial stability and low phase transition temperature and a preparation method thereof. The vanadium dioxide-based symmetrical sandwich structure thermal control film is prepared by sequentially sputtering an inorganic functional layer, a vanadium dioxide layer and an inorganic functional layer on the surface of a substrate, and the two inorganic functional layers have the same physical and chemical characteristics, have anti-reflection and anti-reflection functions and can effectively protect a vanadium dioxide sandwich layer from being influenced by the space environment; and meanwhile, the bottom inorganic matter functional layer and the top inorganic matter functional layer reduce the phase transition temperature of vanadium dioxide by inducing the crystal form change in the deposition process of the vanadium dioxide layer. The infrared radiance gt of the vanadium dioxide-based symmetrical sandwich structure thermal control film prepared by the method is adjusted within the wavelength range of 1-2.2 microns; the thermal control film prepared by the preparation method disclosed by the invention has the advantages that the temperature is 0.40 DEG C, the phase change temperature is 36-45 DEG C, the spatial stability is high, the preparation conditions are simple, and the preparation parameters are easy to control, so that the thermal control film has higher application potential in the field of aerospace thermal control.

Description

Technical Field

[0001] The present invention belongs to the technical field of thermal control films for spacecraft, and in particular relates to a vanadium dioxide-based symmetrical sandwich structure thermal control film with high spatial stability and low phase transition temperature and a preparation method thereof. Background Art Spacecraft face an extremely complex thermal environment in space. During their service in orbit, they are exposed to radiant heat from the sun and the earth. The amount of heat energy they receive changes as the spacecraft changes its position facing the sun. Given that spacecraft in orbit can only exchange heat with the space environment in the form of thermal radiation, spacecraft need to be equipped with an active thermal control system to intelligently adjust the internal temperature of the spacecraft according to the thermal environment of the spacecraft, to ensure the normal operation of instruments and personnel in the cabin. Unlike the currently widely used active thermal control systems such as mechanical blinds and heat pipes, lightweight, low energy consumption and fast response intelligent thermal control films have become an important requirement for future spacecraft. Thermosensitive materials with low space environment temperature response and a wide range of automatic emissivity control are the key to this type of intelligent thermal control film. Vanadium dioxide (VO2) undergoes an "insulator / metal state" phase transition at 341 K and changes its emissivity in the infrared band. Therefore, it has attracted attention in the field of aerospace intelligent thermal control and a series of related products have been developed (CN108866483A, CN105669194A). However, the current application of VO2 in the field of aerospace thermal control still faces the following two problems: (1) The phase transition temperature of 341 K is much higher than the normal operating temperature of the instruments and personnel in the cabin; (2) On-orbit VO2 is affected by strong space radiation (especially electron and proton radiation) and is prone to attenuation of emissivity regulation performance (usually after one year in orbit, the attenuation rate of the emissivity regulation value of an earth-orbiting satellite is ≥20%). At present, the VO2 layer in the intelligent thermal control film reported in the literature and patents mainly uses metal ion doping (such as CN104030355A, CN113998736A, CN104058598A) and heat treatment to control the VO2 crystallization dynamics (CN102912308A, CN104261873A, CN104445990A) and other methods to reconstruct its crystal structure to achieve the purpose of reducing the phase transition temperature, but the relevant technical process window is narrow, the preparation process requires strict control of process parameters and requires huge initial investment. On the other hand, the use of inorganic covering layers is a common method to improve the spatial stability of VO2 (CN108866483A, CN109095499A), but the current inorganic covering layer only reflects the protection function and does not affect the VO2 phase transition temperature characteristics. Summary of the invention In order to solve the problem that the process window of the existing VO2 intelligent thermal control film preparation technology method is narrow and the process parameters need to be strictly controlled during the preparation process, the present invention proposes a new vanadium dioxide-based symmetrical sandwich structure and a corresponding preparation method to prepare a VO2 intelligent thermal control film with high spatial stability and low phase transition temperature. The vanadium dioxide-based thermal control film that can be used to adjust the temperature in the intelligent adjustment cabin of an on-orbit spacecraft to a suitable temperature for instruments / staff and can serve in space for a long time is successfully provided, which promotes the application of vanadium dioxide in the field of aerospace intelligent thermal control.

[0002] The objective of the present invention is achieved through the following technical solutions: In the first aspect, the present invention provides a vanadium dioxide-based sandwich structure thermal control film, wherein the vanadium dioxide-based symmetrical sandwich structure thermal control film structure is sequentially composed of a base layer, an inorganic functional layer, a vanadium dioxide layer, and an inorganic functional layer; wherein the two inorganic functional layers are the same inorganic substance with the same physical and chemical composition.

[0003] As an embodiment, the inorganic functional layer is silicon nitride, boron nitride, hafnium oxide or tin oxide.

[0004] As an embodiment, the substrate is a quartz wafer, a silicon wafer, a transparent sapphire wafer or a corundum wafer.

[0005] As an embodiment, the thickness of the base layer is 500 μm to 2 mm, the thickness of the inorganic functional layer is 100 nm to 1 μm, and the thickness of the vanadium dioxide layer is 50 nm to 500 nm.

[0006] In a second aspect, the present invention relates to a method for preparing a vanadium dioxide-based sandwich structure thermal control film, the method comprising the following steps: S1. After the substrate is cleaned and dried, an inorganic functional layer is deposited on the surface of the substrate using a sputtering target and radio frequency magnetron sputtering technology; S2, depositing a VO2 layer on the surface of the deposited inorganic functional layer using a DC magnetron sputtering device; S3. Deposit an inorganic functional layer on the surface of VO2 using a radio frequency magnetron sputtering device.

[0007] As an embodiment, in step S1, the sputtering target is one of silicon nitride, boron nitride, hafnium oxide, and tin oxide.

[0008] As an implementation scheme, in step S1, during sputtering, the substrate is heated to 300-500°C, argon gas (10-50 sccm) and auxiliary deposition gas (0.2-20 sccm) are introduced into the sputtering chamber and the gas pressure is maintained at 0.1-0.5 Pa.

[0009] As an implementation scheme, in step S1, the temperature is kept at 0.5 to 2 h after deposition.

[0010] As an embodiment, in step S2, during sputtering, the substrate is heated to 250-500°C, 20-200 sccm argon gas and 0.2-20 sccm auxiliary deposition gas are introduced into the sputtering chamber and the gas pressure is maintained at 0.1-10 Pa. In some implementation examples, the substrate is heated to 350°C, 80 sccm argon gas and 2.1 sccm auxiliary deposition gas are introduced into the sputtering chamber and the gas pressure is maintained at 1.0 Pa.

[0011] As an embodiment, in step S2, metal vanadium is used as a sputtering target, the sputtering power is 50-400 W, and the sputtering time is controlled to be 1-30 min. In some implementation examples, metal vanadium is used as a sputtering target, the sputtering power is 200 W, and the sputtering time is controlled to be 12 min.

[0012] As an embodiment, in step S2, the purity of the metal vanadium sputtering target is 99.99%. As an embodiment, in step S3, during sputtering, the substrate is heated to 300-500°C, argon gas (10-50 sccm) and an auxiliary deposition gas (0.2-20 sccm) are introduced into the sputtering chamber and the gas pressure is maintained at 0.1-0.5 Pa.

[0013] As an implementation scheme, in step S3, the temperature is kept at 0.5 to 2 h after deposition.

[0014] As an embodiment, the auxiliary deposition gas is one of nitrogen and oxygen.

[0015] In some specific implementation examples, the method for preparing a vanadium dioxide-based symmetrical sandwich structure thermal control film by magnetron sputtering is performed according to the following steps: Step 1: Deposit the inorganic functional layer A on the substrate surface using a radio frequency magnetron sputtering device The substrate is ultrasonically cleaned with acetone, methanol, ultrapure water and acetone in sequence for 30-60 min. After drying, the substrate is fixed on a sample stage in the cavity of a high-frequency magnetron sputtering device. After the cavity is evacuated to a background vacuum, the substrate is heated to 300-500 ° C. Then, argon gas (10-50 sccm) and an auxiliary deposition gas (0.2-20 sccm) are introduced into the cavity and the gas pressure is maintained at 0.1-0.5 Pa. The inorganic material is deposited on the surface of the substrate using a sputtering target and radio frequency magnetron sputtering technology and kept warm for 0.5-2 h to obtain an inorganic functional layer A. Step 2: Deposit a VO2 layer on the surface of the inorganic functional layer A using a DC magnetron sputtering device After the chamber was evacuated to the base vacuum, the substrate was heated to 350°C, and then 80 sccm of argon and 2.1 sccm of gas were introduced into the chamber and the gas pressure was maintained at 1.0 Pa. DC magnetron sputtering technology was used, with metal vanadium as the sputtering target, the sputtering power was 200 W, and the sputtering time was controlled to be 12 min, to grow a VO2 layer on the surface of the inorganic functional layer A; Step 3: Deposit the inorganic functional layer A on the VO2 surface using a radio frequency magnetron sputtering device After the chamber is evacuated to the background vacuum, the substrate is heated to 300-500 °C, and then argon gas (10-50 sccm) and an auxiliary deposition gas (0.2-20 sccm) are introduced into the chamber and the gas pressure is maintained at 0.1-0.5 Pa. Using the same sputtering target material and RF magnetron sputtering technology as in step 1, an inorganic functional layer A is prepared on the VO2 surface after deposition and insulation for 1 h, forming a vanadium dioxide-based symmetrical sandwich structure thermal control film.

[0016] In addition, the use of the thermal control film of the present invention, or the thermal control film prepared by the aforementioned method in the preparation of aerospace thermal control devices also falls within the protection scope of the present invention. Compared with the prior art, the present invention has the following beneficial effects: 1) The vanadium dioxide-based symmetrical sandwich structure thermal control film of the present invention is prepared by stacking by a magnetron sputtering method. At the same time, the inorganic functional layers on both sides of the VO2 phase change layer in the sandwich structure are one of silicon nitride, boron nitride, hafnium oxide, and tin oxide with the same physical and chemical composition. Therefore, the preparation conditions of the method of the present invention are simple and the preparation parameters are easy to control. 2) The inorganic functional layer of the sandwich structure of the present invention has the following three functions at the same time: (1) increasing the transmittance and reducing the reverse to improve the emissivity adjustment value of the sandwich VO2 layer before and after the phase transition; (2) high space durability to improve the proton and electron radiation resistance of the sandwich VO2 layer, and improve the service life of the thermal control coating; (3) inducing the crystalline morphology of the vanadium dioxide layer to change during the deposition process to achieve a decrease in the phase transition temperature of vanadium dioxide. The third function is proposed and used for the first time in the present invention to reduce the phase transition temperature of vanadium dioxide. 3) The vanadium dioxide-based symmetrical sandwich structure thermal control film of the present invention has an infrared emissivity adjustment of >0.4 in the wavelength range of 1~2.2 μm, a phase transition temperature of 36~45 ℃, high spatial stability, simple preparation conditions and easy control of preparation parameters. Therefore, the thermal control film of the present invention has high application potential in the field of aerospace thermal control. BRIEF DESCRIPTION OF THE DRAWINGS Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 . Schematic diagram of the structure of vanadium dioxide-based sandwich thermal control film; Figure 2 . SiN / VO2 / SiN / quartz thermal control film phase change transmittance adjustment value; Figure 3 . SiN / VO2 / SiN / quartz thermal control film insulating state / metallic state phase change response curve; Figure 4 . Phase change transmittance adjustment value of SiN / VO2 / SiN / quartz thermal control film after simulating one year of proton irradiation dose in geosynchronous orbit under 30 keV proton irradiation conditions; Figure 5 . Phase change transmittance adjustment value of SiN / VO2 / SiN / quartz thermal control film after simulating one year of proton irradiation dose in geosynchronous orbit under 90 keV proton irradiation conditions; Figure 6 . HfO2 / VO2 / HfO2 / transparent sapphire thermal control film phase change transmittance adjustment value; Figure 7 . Insulating / metallic phase transition response curve of HfO2 / VO2 / HfO2 / transparent sapphire thermal control film; Figure 8 . The phase change transmittance adjustment value of HfO2 / VO2 / HfO2 / transparent sapphire thermal control film after simulating one year of proton irradiation dose in geosynchronous orbit under 30 keV proton irradiation conditions; Fig. 9 . The phase change transmittance adjustment value of HfO2 / VO2 / HfO2 / transparent sapphire thermal control film after simulating one year of proton irradiation dose in geosynchronous orbit under 90 keV proton irradiation conditions; Fig.10 . VO2 / SiN / quartz thermal control film phase change transmittance adjustment value. DETAILED DESCRIPTION

[0017] The present invention is described in detail below in conjunction with embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, some adjustments and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0018] The present invention provides a vanadium dioxide-based sandwich structure thermal control film with high dimensional stability and low phase transition temperature. Figure 1 As shown, the film composition is a base layer, an inorganic functional layer A, a vanadium dioxide layer (VO2 phase change layer), and an inorganic functional layer A, wherein the two inorganic functional layers are the same inorganic substance with the same physical and chemical composition. The vanadium dioxide-based sandwich structure thermal control film is prepared by magnetron sputtering, which includes the following three steps: Step 1: Depositing an inorganic functional layer A on the surface of the substrate by using a radio frequency magnetron sputtering device, wherein the functional layer is one of silicon nitride, boron nitride, hafnium oxide, and tin oxide; Step 2: Depositing a VO2 thin film on the surface of the inorganic functional layer A using a DC magnetron sputtering device, wherein the deposition method is reactive magnetron sputtering using a metal vanadium target; Step three: Deposit an inorganic functional layer A on the surface of VO2 using a radio frequency magnetron sputtering device. The preparation method and physical and chemical properties of the inorganic functional layer are consistent with those described in step one. In step 1, the substrate is one of quartz, silicon, corundum, and transparent sapphire, the auxiliary deposition gas is one of nitrogen and oxygen, and the sputtering target is one of silicon nitride, boron nitride, hafnium oxide, and tin oxide. In step 2, the purity of the metal vanadium sputtering target is 99.99%. The present invention is further described in detail below with reference to specific embodiments. Example 1 This embodiment relates to a vanadium dioxide-based sandwich structure thermal control film structure with high dimensional stability and low phase transition temperature. Figure 1 As shown, the film composition is a base layer, an inorganic functional layer A, a vanadium dioxide layer (VO2 phase change layer), and an inorganic functional layer A. The specific preparation steps are as follows: Step 1: Use acetone, methanol, ultrapure water, and acetone to ultrasonically clean the quartz plate for 30 minutes in sequence. After drying, fix the substrate on the sample stage in the cavity of the dual-target magnetron sputtering device. After the cavity is evacuated to a background vacuum of 0.0006 Pa, heat the substrate to 350 ° C, and then introduce 40 sccm of high-purity argon and 10 sccm of high-purity nitrogen into the cavity and maintain the gas pressure at 0.5 Pa. Use 99.99% silicon nitride as the sputtering target, the sputtering power is 200 W, and the sputtering time is 15 minutes to obtain a SiN inorganic functional layer; Step 2: After the chamber is evacuated to the base vacuum, the substrate is heated to 350 °C, and then 80 sccm of argon and 2.1 sccm of oxygen are introduced into the chamber and the pressure is maintained at 1.0 Pa. DC magnetron sputtering technology is used, with metal vanadium as the sputtering target, the sputtering power is 200 W, and the sputtering time is controlled to be 12 min, to grow a VO2 layer on the surface of the SiN inorganic functional layer; Step 3: After the chamber is evacuated to a background vacuum of 0.0006 Pa, the substrate is heated to 350°C, and then 40 sccm of high-purity argon and 10 sccm of high-purity nitrogen are introduced into the chamber and the gas pressure is maintained at 0.5 Pa. 99.99% silicon nitride is used as the sputtering target, the sputtering power is 200 W, the sputtering time is 15 min, and after 1 h of insulation, a SiN inorganic functional layer is grown on the VO2 surface to form a SiN / VO2 / SiN / quartz thermal control film; the quartz substrate layer is 1 mm thick, the thickness of each SiN inorganic functional layer is 400 nm, and the thickness of the vanadium dioxide layer is 100 nm.

[0019] The test results of the SiN / VO2 / SiN / quartz thermal control film prepared in this embodiment are as follows: (1) SiN has a refractive index close to that of insulating VO2 and has high spatial stability. Therefore, the SiN coating layer has the function of enhancing transmittance and reducing reflection and effectively improves the spatial stability of the VO2 sandwich layer. (2) The phase transition temperature is 320K, such as Figure 2 . (3) In the 1~2.2 μm band, the transmittance adjustment value of SiN / VO2 / SiN / quartz thermal control film is 0.47, such as Figure 3 . (4) After simulating the proton irradiation dose of geosynchronous orbit for one year under 30 keV proton irradiation conditions, the average transmittance adjustment value in the 1~2.2 μm band is 0.41, as shown in Figure 4 .

[0020] (5) After simulating the one-year electron irradiation dose in geosynchronous orbit under 90 keV electron irradiation conditions, the average transmittance adjustment value in the 1~2.2 μm band is 0.38, as shown in Figure 5 . Example 2 The vanadium dioxide-based sandwich structure thermal control film with high dimensional stability and low phase transition temperature of this embodiment is specifically prepared in the following steps: Step 1: Use acetone, methanol, ultrapure water, and acetone to ultrasonically clean the transparent sapphire substrate for 15 minutes in sequence. After drying, fix the substrate on the sample stage in the cavity of the dual-target frequency magnetron sputtering device. After the cavity is evacuated to a background vacuum of 0.0006 Pa, heat the substrate to 400 ° C, and then introduce 40 sccm of high-purity argon and 10 sccm of high-purity oxygen into the cavity and maintain the gas pressure at 0.5 Pa. Use 99.99% hafnium dioxide as the sputtering target, the sputtering power is 300 W, and the sputtering time is 10 min to obtain the HfO2 inorganic functional layer; Step 2: Using the same experimental technical parameters as in Example 1, a VO2 layer is grown on the surface of the HfO2 inorganic functional layer; Step 3: After the chamber is evacuated to the base vacuum of 0.0006 Pa, the substrate is heated to 400 °C, and then 40 sccm of high-purity argon and 10 sccm of high-purity oxygen are introduced into the chamber and the pressure is maintained at 0.5 Pa. 99.99% hafnium dioxide is used as the sputtering target, the sputtering power is 300 W, the sputtering time is 10 min, and after 1 h of heat preservation, the HfO2 inorganic functional layer is grown on the VO2 surface to form a HfO2 / VO2 / HfO2 / transparent sapphire thermal control film. The transparent sapphire substrate layer is 2 mm thick, the HfO2 inorganic functional layer is 50 nm thick, and the vanadium dioxide layer is 100 nm thick. The test results of the HfO2 / VO2 / HfO2 / transparent sapphire thermal control film prepared in this embodiment are as follows: (1) HfO2 has high dimensional stability, so the HfO2 coating can effectively improve the service stability of thermal control films. (2) The phase transition temperature is 316 K, such as Figure 6 . (3) In the 1~2.2 μm band, the transmittance adjustment value of HfO2 / VO2 / HfO2 / transparent sapphire thermal control film is 0.6, such as Figure 7 . (4) After simulating the proton irradiation dose of geosynchronous orbit for one year under 30 keV proton irradiation conditions, the average transmittance adjustment value in the 1~2.2 μm band is 0.54, as shown in Figure 8 . (5) After simulating the one-year electron irradiation dose in geosynchronous orbit under 90 keV electron irradiation conditions, the average transmittance adjustment value in the 1-2.2 μm band is 0.50, such as Fig. 9 . Comparative Example 1 The thermal control film structure of this comparative example is a base layer, an inorganic functional layer A, and a vanadium dioxide layer (VO2 phase change layer) in sequence; the specific preparation steps are as follows: Step 1: Use acetone, methanol, ultrapure water, and acetone to ultrasonically clean the quartz plate for 30 minutes in sequence. After drying, fix the substrate on the sample stage in the cavity of the dual-target magnetron sputtering device. After the cavity is evacuated to a background vacuum of 0.0006 Pa, heat the substrate to 350 ° C, and then introduce 40 sccm of high-purity argon and 10 sccm of high-purity nitrogen into the cavity and maintain the gas pressure at 0.5 Pa. Use 99.99% silicon nitride as the sputtering target, the sputtering power is 200 W, and the sputtering time is 15 minutes to obtain a SiN inorganic functional layer; Step 2: After the chamber is evacuated to the base vacuum, the substrate is heated to 350 °C, and then 80 sccm argon and 2.1 sccm oxygen are introduced into the chamber and the pressure is maintained at 1.0 Pa. DC magnetron sputtering technology is used, with metal vanadium as the sputtering target, the sputtering power is 200 W, and the sputtering time is controlled to be 12 min. The VO2 layer is grown on the surface of the SiN inorganic functional layer. Among them, the thickness of the quartz substrate layer is 1 mm, the thickness of the SiN inorganic functional layer is 400 nm, and the thickness of the vanadium dioxide layer is 100 nm.

[0021] The test results of the VO2 / SiN / quartz thermal control film prepared in this comparative example are as follows: (1) The phase transition temperature is 349K, such as Fig.10 . (2) In the 1~2.2 μm band, the transmittance adjustment value of VO2 / SiN / quartz thermal control film is 0.41. (3) After simulating one year of proton irradiation in geosynchronous orbit under 30 keV proton irradiation conditions, the average transmittance adjustment value in the 1-2.2 μm band is 0.25. (4) After simulating one year of electron irradiation in geosynchronous orbit under 90 keV electron irradiation conditions, the average transmittance adjustment value in the 1-2.2 μm band is 0.20.

[0022] Comparative Example 2 The thermal control film structure of this comparative example is a base layer, an inorganic functional layer A, a vanadium dioxide layer (VO2 phase change layer), and an inorganic functional layer B in sequence; the specific preparation steps are as follows: Step 1: Use acetone, methanol, ultrapure water, and acetone to ultrasonically clean the quartz plate for 30 minutes in sequence. After drying, fix the substrate on the sample stage in the cavity of the dual-target magnetron sputtering device. After the cavity is evacuated to a background vacuum of 0.0006 Pa, heat the substrate to 350 ° C, and then introduce 40 sccm of high-purity argon and 10 sccm of high-purity nitrogen into the cavity and maintain the gas pressure at 0.5 Pa. Use 99.99% silicon nitride as the sputtering target, the sputtering power is 200 W, and the sputtering time is 15 minutes to obtain a SiN inorganic functional layer; Step 2: After the chamber is evacuated to the background vacuum, the substrate is heated to 350 ° C, and then 80 sccm argon and 2.1 sccm oxygen are introduced into the chamber and the gas pressure is maintained at 1.0 Pa. DC magnetron sputtering technology is used, with metal vanadium as the sputtering target, the sputtering power is 200 W, and the sputtering time is controlled to be 12 min. A VO2 layer is grown on the surface of the SiN inorganic functional layer.

[0023] Step 3: After the chamber is evacuated to the background vacuum of 0.0006 Pa, the substrate is heated to 350°C, and then 40 sccm of high-purity argon and 2 sccm of high-purity nitrogen are introduced into the chamber and the pressure is maintained at 0.5 Pa. 99.99% silicon dioxide is used as the sputtering target, the sputtering power is 150 W, the sputtering time is 12 minutes, and after 1 hour of heat preservation, the SiO2 inorganic functional layer B is grown on the VO2 surface to form a SiO2 / VO2 / SiN / quartz thermal control film. The thickness of the quartz substrate layer is 1 mm, the thickness of the SiN inorganic functional layer is 400 nm, the thickness of the vanadium dioxide layer is 100 nm, and the thickness of the SiO2 inorganic functional layer is 400 nm.

[0024] The test results of the SiO2 / VO2 / SiN / quartz thermal control film prepared in this comparative example are as follows: (1) The phase transition temperature is 332K. (2) In the 1~2.2 μm band, the transmittance adjustment value of VO2 / SiN / quartz thermal control film is 0.43. (3) After simulating one year of proton irradiation in geosynchronous orbit under 30 keV proton irradiation conditions, the average transmittance adjustment value in the 1-2.2 μm band was 0.3. (4) After simulating one year of electron irradiation in geosynchronous orbit under 90 keV electron irradiation conditions, the average transmittance adjustment value in the 1-2.2 μm band was 0.28.

[0025] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A vanadium dioxide-based sandwich structure thermal control film, characterized in that: The vanadium dioxide-based symmetrical sandwich structure thermal control film structure comprises a base layer, an inorganic functional layer, a vanadium dioxide layer, and an inorganic functional layer in sequence; wherein the two inorganic functional layers are the same inorganic substance with the same physical and chemical composition.

2. The vanadium dioxide-based sandwich structure thermal control film according to claim 1, characterized in that: The inorganic functional layer is silicon nitride, boron nitride, hafnium oxide or tin oxide.

3. The vanadium dioxide-based sandwich structure thermal control film according to claim 1, characterized in that: The substrate is a quartz sheet, a silicon sheet, a transparent sapphire sheet or a corundum sheet.

4. The vanadium dioxide-based sandwich structure thermal control film according to claim 1, characterized in that: The thickness of the base layer is 500μm ~ 2 mm, the thickness of the inorganic functional layer is 100 nm ~ 1μm, and the thickness of the vanadium dioxide layer is 50 nm ~ 500 nm.

5. A method for preparing a vanadium dioxide-based sandwich structure thermal control film as claimed in any one of claims 1 to 4, characterized in that: The method comprises the following steps: S1. After the substrate is cleaned and dried, an inorganic functional layer is deposited on the surface of the substrate using a sputtering target and radio frequency magnetron sputtering technology; S2, depositing a VO2 layer on the surface of the deposited inorganic functional layer using a DC magnetron sputtering device; S3. Deposit an inorganic functional layer on the surface of VO2 using a radio frequency magnetron sputtering device.

6. The method for preparing the vanadium dioxide-based sandwich structure thermal control film according to claim 5, characterized in that: In step S1, the sputtering target is one of silicon nitride, boron nitride, hafnium oxide, and tin oxide; during sputtering, the substrate is heated to 300-500 ° C, 10-50 sccm of argon gas and 0.2-20 sccm of auxiliary deposition gas are introduced into the sputtering chamber and the gas pressure is maintained at 0.1-0.5 Pa; after deposition, the temperature is kept for 0.5-2 h.

7. The method for preparing the vanadium dioxide-based sandwich structure thermal control film according to claim 5, characterized in that: In step S2, during sputtering, the substrate is heated to 250-500°C, 20-200 sccm argon and 0.2-20 sccm auxiliary deposition gas are introduced into the sputtering chamber and the gas pressure is maintained at 0.1-10 Pa; metal vanadium is used as the sputtering target, the sputtering power is 50-400 W, and the sputtering time is controlled to be 1-30 min.

8. The method for preparing the vanadium dioxide-based sandwich structure thermal control film according to claim 5, characterized in that: In step S3, during sputtering, the substrate is heated to 300-500°C, 10-50 sccm of argon gas and 0.2-20 sccm of an auxiliary deposition gas are introduced into the sputtering chamber and the gas pressure is maintained at 0.1-0.5 Pa; after deposition, the substrate is kept warm for 0.5-2 h.

9. The method for preparing a vanadium dioxide-based sandwich structure thermal control film according to any one of claims 5 to 8, characterized in that: The auxiliary deposition gas is one of nitrogen and oxygen.

10. Use of the thermal control film as claimed in any one of claims 1 to 4, or the thermal control film prepared by the method as claimed in any one of claims 5 to 9 in the preparation of aerospace thermal control devices.

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