Low-cost high-transparency vo2 nanoparticle thermochromic smart window with double optical matching layer structure and preparation method thereof

Abstract

The application discloses a low-cost high-transparency VO2 nanoparticle thermochromic smart window with a double optical matching layer structure and a preparation method thereof, and belongs to the technical field of smart windows and passive heat management materials.The application aims to solve the problems that the prior art cannot simultaneously realize effective ion blocking and environmental protection on the basis of simplifying the film system structure and obtaining the unification of high visible light transmittance and high solar light modulation capacity on a low-cost substrate system.The smart window comprises, from bottom to top, a soda-lime glass substrate, a first optical matching layer, a W-doped VO2 nanoparticle thermochromic functional layer and a second optical matching layer.The method comprises the following steps: one, depositing the first optical matching layer;two, depositing the W-doped VO2 continuous film and in-situ annealing;three, depositing the second optical matching layer;and four, annealing.The application is used for the low-cost high-transparency VO2 nanoparticle thermochromic smart window with the double optical matching layer structure and the preparation thereof.

Description

Technical Field

[0001] This invention belongs to the technical field of intelligent windows and passive thermal management materials. Background Technology

[0002] With the continuous advancement of modern industry and urbanization, the proportion of energy consumption in the building sector continues to rise. Statistics show that energy consumption during building operation accounts for approximately 40% of global energy consumption, with heat exchange through the building envelope accounting for a significant proportion. Windows, as the light-transmitting and thermally weakest part of the building envelope, are the main channel for heat exchange between indoors and outdoors. In summer, solar radiation enters the room through windows, leading to increased cooling loads; in winter, the loss of infrared radiation may increase heating energy consumption. Therefore, intelligent window technology, which can adaptively adjust solar radiation transmission behavior according to changes in ambient temperature, has become a hot research topic in building energy conservation.

[0003] Among the various smart window technologies, the passive control scheme based on the thermally induced phase transition effect of vanadium dioxide (VO2) has attracted widespread attention due to its lack of external power supply, simple structure, and good reversibility. VO2 undergoes a reversible metal-insulator phase transition at approximately 68℃. Before and after the phase transition, its optical constants in the near-infrared band change significantly, while its transmittance characteristics in the visible light region change only slightly. This characteristic makes it an ideal material for achieving a balance between high visible light transmittance and high solar light modulation capability.

[0004] Although vanadium dioxide (VO2) has shown great potential in the field of smart windows due to its reversible metal-insulator phase transition properties, its practical application is still constrained by three core contradictions:

[0005] First, there is the transmittance bottleneck caused by optical refractive index mismatch. In practical applications, VO2-based thermochromic smart windows still face the core contradiction of simultaneously achieving high transmittance and low cost. Traditional high-performance smart windows often use quartz glass or special high-transmittance substrate materials, which have stable refractive indices and few impurities, but are expensive, hindering large-scale building adoption. In contrast, ordinary float soda-lime glass is low-cost and produced in large quantities, making it the mainstream material in the construction industry. However, the refractive index of soda-lime glass is about 1.5, while the real refractive index of VO2 in the visible light band is typically 2.5~3.0, showing a significant abrupt change in refractive index between the two.

[0006] According to classical electromagnetic wave propagation theory, when light is incident perpendicularly from one medium to the interface of another medium, its reflectivity can be expressed by Fresnel's formula:

[0007]

[0008] Where n0 is the refractive index of the incident medium and n1 is the refractive index of the transmitted medium. When n0 = 1.5 and n1 ≈ 2.7, the theoretical reflectivity of a single interface can reach 10%~15%. This means that, without optical matching design, even if the VO2 material itself has low absorption, significant transmittance loss will still occur due to interface reflection. Furthermore, there is also a sudden change in refractive index between the VO2 functional layer and the air interface (n ≈ 1.0), leading to enhanced reflection at the second interface. The superposition of reflections at both interfaces makes it difficult to improve the overall visible light transmittance.

[0009] Therefore, the fundamental physical bottleneck limiting the high transmittance performance of VO2 smart windows is not simply a matter of material absorption or film thickness, but rather the interface Fresnel reflection loss caused by electromagnetic impedance mismatch.

[0010] In existing technologies, some solutions improve optical performance by constructing multilayer dielectric film systems or forming Fabry-Perot resonant cavity structures. However, such structures typically have a large number of layers and a large film thickness, resulting in complex manufacturing processes. Furthermore, they are often coupled with infrared emissivity modulation, making it difficult to optimize visible light transmittance while maintaining structural simplicity. At the same time, multilayer complex film systems place higher demands on equipment precision and cost, hindering the large-scale application of low-cost soda-lime glass systems.

[0011] Second, there are lifespan issues caused by substrate ion diffusion and the environmental sensitivity of the functional layer. Soda-lime glass contains a large amount of Na. + Ca 2+ Alkali and alkaline earth metal ions, during high-temperature deposition or long-term use, can diffuse along defects or grain boundaries into the VO2 layer, leading to stoichiometric shifts, degradation of phase transition properties, and even failure. Simultaneously, VO2 is extremely sensitive to water and oxygen, and when exposed to the atmosphere, it readily oxidizes to form high-valence vanadium oxides such as V2O5, losing its reversible phase transition capability. Therefore, achieving effective ion blocking and environmental protection simultaneously on a low-cost substrate becomes crucial in determining the device's lifespan.

[0012] Third, there is the challenge of synergistic design and controllable fabrication of film systems. An ideal technical solution needs to address the aforementioned optical and stability issues simultaneously within a minimalist film system structure, and provide a scalable fabrication method that can precisely control the thickness, refractive index, density, and microstructure of each layer to ensure repeatability and consistency of performance.

[0013] Therefore, how to achieve a balance between high visible light transmittance and high solar light modulation capability on a low-cost substrate system by reasonably constructing a refractive index transition layer based on the principle of electromagnetic wave propagation and simplifying the film structure, thereby achieving a synergistic optimization of interface impedance matching and interference antireflection, while simultaneously realizing effective ion blocking and environmental protection, is a key technical problem that urgently needs to be solved. Summary of the Invention

[0014] This invention aims to address the problem that existing technologies cannot achieve a balance between high visible light transmittance and high solar light modulation capability on a low-cost substrate system while simplifying the film structure, and cannot simultaneously achieve effective ion blocking and environmental protection. Therefore, it provides a low-cost, highly transparent VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure and its preparation method.

[0015] A low-cost, high-transparency VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure, comprising, from bottom to top, a soda-lime glass substrate, a first optical matching layer, a W-doped VO2 nanoparticle thermochromic functional layer, and a second optical matching layer.

[0016] Both the first optical matching layer and the second optical matching layer are oxynitride thin films or metal oxide thin films.

[0017] If the refractive index of the first optical matching layer at the visible light center wavelength λ0 is n1, then 1.55≤n1≤2.40;

[0018] If the refractive index of the second optical matching layer at the visible light center wavelength λ0 is n3, then 1.10≤n3≤2.20;

[0019] Let the refractive index of the soda-lime glass substrate at the visible light center wavelength λ0 be n0, and the refractive index of the W-doped VO2 nanoparticle thermochromic functional layer at the visible light center wavelength λ0 be n2, then n0 <n1<n2;

[0020] Let the thickness of the first optical matching layer be d1 and the thickness of the second optical matching layer be d3. Then the optical thickness of the first optical matching layer is n1×d1=λ0 / 4±λ0 / 4×30%, and the optical thickness of the second optical matching layer is n3×d3=λ0 / 4±λ0 / 4×30%.

[0021] A low-cost, highly transparent VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure is prepared by the following steps:

[0022] 1. A first optical matching layer is deposited on a soda-lime glass substrate using reactive magnetron sputtering or high-power pulsed magnetron sputtering;

[0023] 2. A W-doped VO2 continuous thin film was deposited on the first optical matching layer by high-power pulsed magnetron sputtering and then annealed in situ to obtain a W-doped VO2 nanoparticle thermochromic functional layer.

[0024] 3. A second optical matching layer is deposited on the thermochromic functional layer of W-doped VO2 nanoparticles using reactive magnetron sputtering or high-power pulsed magnetron sputtering.

[0025] IV. Annealing, which is a low-cost, highly transparent VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure.

[0026] The beneficial effects of this invention are:

[0027] This invention achieves a balance between high visible light transmittance and good solar light modulation capability in a low-cost soda-lime glass system through the synergistic design and integrated fabrication method of a "dual-functional optical matching layer".

[0028] (1) Achieve high visible light transmittance.

[0029] By introducing SiO with precisely matched refractive index x N y / AlO w N z The device employs a first and second optical matching layer of metal oxide, designed strictly according to the λ / 4 optical thickness principle. This design significantly reduces interface reflection loss, enabling the device to achieve a high average visible light transmittance T0 with only three ultra-simple three-layer film system. lum It can stably reach over 68%, and under optimized conditions, it can exceed 70%, meeting the building's lighting requirements.

[0030] (2) Achieve good long-term stability.

[0031] The high-temperature HiPIMS dense deposition of the first matching layer effectively suppressed the substrate Na+. + Ca 2+ Plasma diffusion; the low-temperature continuous coverage structure of the second matching layer effectively blocks water and oxygen permeation. After 500 hours of accelerated aging at 85℃ / 85%RH, ΔT sol The retention rate can exceed 80%, T lum The retention rate can exceed 84%, demonstrating good environmental reliability.

[0032] (3) Achieve a balance between performance and cost.

[0033] Using ordinary float soda-lime glass as the substrate, all film deposition can be completed under the unified HiPIMS platform by controlling the process window, avoiding multiple equipment conversions and complex film system superposition, and has good potential for large-scale application.

[0034] This invention does not simply employ a conventional λ / 4 antireflective coating. Instead, under the dual constraints of ion diffusion and environmental sensitivity in a low-cost soda-lime glass substrate, it couples the design of refractive index range limitation, optical thickness control, and deposition temperature window to achieve an intrinsic unity of optical matching and physical protection functions, thereby improving performance under simplified structural conditions. Attached Figure Description

[0035] Figure 1This is a schematic diagram of the low-cost, high-transparency VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure of the present invention. 1 is a soda-lime glass substrate, 2 is the first optical matching layer, 3 is a W-doped VO2 nanoparticle thermochromic functional layer, and 4 is the second optical matching layer. Detailed Implementation

[0036] Specific implementation method one, combined with Figure 1 Detailed description: This embodiment is a low-cost, high-transparency VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure. From bottom to top, it consists of a soda-lime glass substrate, a first optical matching layer, a W-doped VO2 nanoparticle thermochromic functional layer, and a second optical matching layer.

[0037] Both the first optical matching layer and the second optical matching layer are oxynitride thin films or metal oxide thin films.

[0038] If the refractive index of the first optical matching layer at the visible light center wavelength λ0 is n1, then 1.55≤n1≤2.40;

[0039] If the refractive index of the second optical matching layer at the visible light center wavelength λ0 is n3, then 1.10≤n3≤2.20;

[0040] Let the refractive index of the soda-lime glass substrate at the visible light center wavelength λ0 be n0, and the refractive index of the W-doped VO2 nanoparticle thermochromic functional layer at the visible light center wavelength λ0 be n2, then n0 <n1<n2;

[0041] Let the thickness of the first optical matching layer be d1 and the thickness of the second optical matching layer be d3. Then the optical thickness of the first optical matching layer is n1×d1=λ0 / 4±λ0 / 4×30%, and the optical thickness of the second optical matching layer is n3×d3=λ0 / 4±λ0 / 4×30%.

[0042] The first optical matching layer described in this specific embodiment is used to reduce the interface reflection between the soda-lime glass and the VO2 functional layer and to block the migration of substrate ions. The second optical matching layer is used to reduce the interface reflection between the VO2 functional layer and the air and to block the permeation of environmental water and oxygen.

[0043] Principle: This specific implementation proposes a three-layer ultra-simple film structure based on a "dual-functional optical matching layer." The core concept lies in introducing a newly defined "optical matching layer" between the soda-lime glass substrate and the VO2 functional layer, and between the VO2 functional layer and air. This layer is not a traditional single-functional layer (such as a blocking layer or protective layer), but an independent functional layer that intrinsically integrates the two core functions of optical anti-reflection and physical protection. Its design logic follows two parallel main lines: first, by precisely matching the refractive index and controlling the λ / 4 optical thickness, interface reflection is fundamentally eliminated; second, through a dense microstructure design, it naturally possesses the ability to block ion diffusion and protect against environmental erosion.

[0044] First, the first optical matching layer: unifying the construction of refractive index gradient and ion blocking function.

[0045] The first optical matching layer is deposited on a soda-lime glass substrate, preferably using silicon oxynitride (SiO2). x N y ), aluminum oxynitride (AlO) w N z Thin films. These materials have two major advantages: first, their refractive index can be continuously adjusted between 1.5 and 2.2 by adjusting the O / N atomic ratio, providing great flexibility for precise optical design; second, their amorphous or nanocrystalline structures can achieve extremely high density under appropriate deposition conditions, thereby intrinsically suppressing ion diffusion.

[0046] In addition, traditional metal oxides that meet the refractive index requirements, such as hafnium dioxide (HfO2) (~2.0), zirconium dioxide (ZrO2) (1.97~2.05), titanium dioxide (TiO2) (2.2~2.4), and zinc oxide (ZnO) (~1.9), can also be used as optical matching layer materials.

[0047] Refractive index design principle: To minimize reflection loss at the glass / VO2 interface, the refractive index n1 of the first matching layer is strictly limited to between the substrate refractive index n0 and the VO2 functional layer refractive index n2, i.e., satisfying:

[0048] n0 <n1<n2;

[0049] Building upon this, an optimization criterion for impedance matching is further introduced: when the refractive indices of the media on both sides of the interface satisfy a geometric mean relationship, the reflection coefficients of both interfaces can be reduced simultaneously, providing optimal initial conditions for subsequent destructive interference. Therefore, the ideal value of n1 should approach:

[0050] ;

[0051] In the formula, n0≈1.5, n2≈2.5~3.0, therefore The tolerance range of ±0.3 ensures both the feasibility of material selection and the ability to achieve acceptable antireflection effects through thickness tuning even when the refractive index deviates from the optimal value.

[0052] Thickness design principle: The first matching layer is designed as a λ / 4 antireflective coating. Its physical thickness d1 and refractive index n1—that is, the optical thickness—should satisfy:

[0053]

[0054] Where λ0 is the center wavelength of visible light, typically 550 nm. This design is based on the principle of thin-film interference: when the incident light generates a phase difference due to half-wave loss between the incident light at the glass / matching layer interface and the reflected light at the matching layer / VO2 interface, the two interfere destructively near the center wavelength, thus significantly reducing the total reflectivity. Since architectural daylighting focuses more on the overall transmittance in the visible light band (380~780 nm) rather than single-point ultra-narrowband optimization, in practical designs, broadband anti-reflection can be achieved by selecting λ0 and combining it with film thickness tolerance (±30%). x N y / AlO w N z The tunable refractive index of metal oxide thin films provides the material basis for achieving this goal.

[0055] The mechanism for achieving ion blocking functionality: The ion blocking capability of the first matching layer does not rely on an additionally designed blocking layer structure, but rather originates from the highly dense microstructure of the film itself. This layer is deposited using a high-temperature HiPIMS process (substrate temperature > 300 °C). HiPIMS technology is known for its high peak power, high ionization rate, and high-density plasma, which can generate a high-energy ion bombardment effect during deposition, significantly enhancing surface atomic mobility, promoting film densification, and reducing porosity and through-hole defect density. The obtained SiO₂... x N y / AlO w N z The metal oxide thin film has a density of ≥95%, and its microstructure can effectively physically block Na from the substrate. + Ca 2+ The longitudinal migration path of plasma inherently achieves ion blocking functionality. In other words, "densification" is considered a key constraint for the first matching layer, alongside "λ / 4 optical thickness control," and its repeatability is ensured through process window design.

[0056] Second, VO2-based thermochromic functional layer: nanoparticle structure and LSPR enhancement mechanism

[0057] The VO2 functional layer is the core functional layer of this invention, preferably a tungsten-doped VO2 (W-VO2) nanoparticle thin film. The W doping amount is controlled within the range of ≤2.0 at.%, and its function is to adjust the phase transition temperature of VO2 from the intrinsic ~68℃ to near room temperature (25~40℃) to match the actual working temperature range of the building environment, thereby improving practicality and comfort.

[0058] This layer was deposited on top of the first matching layer using a HiPIMS process, and through precise control of deposition parameters and subsequent in-situ vacuum annealing, nanoparticle structures with sizes ranging from 30 nm to 120 nm were induced. This structure design has dual optical functions:

[0059] Low-temperature semiconductor state: Subwavelength nanoparticles scatter visible light very weakly, ensuring that the film maintains high transparency in the visible light band;

[0060] High-temperature metallic state: Nanoparticles excite the localized surface plasmon resonance (LSPR) effect, strongly absorbing and reflecting near-infrared solar radiation, thus achieving a significant difference in near-infrared transmittance.

[0061] Therefore, the difference ΔT in the solar transmittance of the device at low and high temperatures... sol It can stably exceed 10%, and its calculation formula is as follows:

[0062] ;

[0063] Where T sol-L T represents the solar transmittance of the device at low temperature (0°C) using the AM 1.5 solar spectrum weighted integral. sol-H The solar transmittance is obtained by weighted integration of the device at high temperature (40℃) using the AM 1.5 solar spectrum.

[0064] Third and second optical matching layers: a combination of symmetrical anti-reflective design and environmental protection.

[0065] The second optical matching layer covers the VO2 functional layer and is also preferably made of SiO2. x N y or AlO w N z An oxynitride / metal oxide thin film system was developed to achieve a unified process platform and continuously tunable refractive index. Its optical design follows an impedance matching principle symmetrical with the first matching layer.

[0066] ;

[0067] Where n4 = 1.0 is the refractive index of air. Since n2 ≈ 2.5~3.0, therefore A tolerance range of ±0.3 ensures that the refractive index landing point can be controlled through composition adjustment within the oxynitride / metal oxide system, while SiO... x N y / AlO w N z The tunability of the refractive index of metal oxide thin films still provides the optimal path to achieving precise matching.

[0068] The second matching layer is also designed with a thickness based on λ / 4 of the antireflective coating:

[0069]

[0070] Its function is to cause destructive interference between the reflected light from the VO2 / matching layer interface and the matching layer / air interface, achieving a second layer of anti-reflection. It is important to emphasize that the first and second matching layers do not work in isolation; they work together in a multi-interface system. Their refractive index placement and thickness tolerance must be coordinated to avoid introducing enhanced reflection or spectral fluctuations on the other side due to strong matching on one side. Through a unified control platform of the entire HiPIMS process, synergistic optimization of the two matching layers can be achieved, ensuring that the final device achieves stable, broadband, and high transmittance performance in the visible light band.

[0071] The environmental protection mechanism: The core physical function of the second matching layer lies in isolating environmental moisture and oxygen, delaying the oxidation and hydrolysis of VO2. Unlike the first matching layer, which pursues "extreme density," the core constraints of the second matching layer are "continuity, low defects, low stress, and long-term coverage." This layer is deposited using a relatively low-temperature HiPIMS process (substrate temperature ≤150℃), which has the following advantages:

[0072] Low-temperature protection: to avoid thermal damage or induction of excessive growth to the underlying VO2 nanoparticle structure, and to maintain the nanomorphology and phase transition properties of the functional layer;

[0073] Stress control: Reduce internal stress in the film, decrease cracking tendency, and ensure macroscopic continuous coverage;

[0074] Defect suppression: By precisely controlling the HiPIMS pulse parameters and the ratio of reactant gases, oxynitride or metal oxide films with fewer defect channels are obtained, thereby effectively isolating water and oxygen formation.

[0075] Under certain process windows, the microstructure of the thin film can exhibit a certain degree of relaxation to release stress, but it must still maintain macroscopic continuous coverage to simultaneously satisfy both optical matching and environmental protection functions. In other words, this specific embodiment does not require the second matching layer to have the same ultra-high density as the first matching layer. Instead, through differentiated design of the process windows, it maximizes compatibility with the structural stability requirements of the underlying VO2 layer while ensuring protective capabilities.

[0076] The ingenuity of this specific implementation does not stem from a single λ / 4 antireflection principle, but rather from the synergistic coupling of refractive index range limitation, optical thickness control, and differential design of deposition temperature window in a low-cost soda-lime glass system, thereby achieving an intrinsic unity of optical matching and physical protection.

[0077] In summary, this specific embodiment uses ordinary soda-lime glass as a low-cost substrate and achieves a thermochromic smart window for VO2 nanoparticles and its integrated deposition method by constructing a double-sided oxynitride or metal oxide optical matching layer to synergistically optimize interface electromagnetic impedance matching and interference antireflection. The smart window utilizes the reversible metal-insulator phase transition characteristics of VO2 material to achieve adaptive temperature control of near-infrared solar radiation. Through the limitation of the refractive index range and the λ / 4 optical thickness design of the double optical matching layer, it significantly improves visible light transmittance while maintaining high solar light modulation capability, and also takes into account ion blocking and environmental protection functions. The technical solution described in this specific embodiment can be widely applied to building energy-saving windows, curtain wall glass, vehicle lighting components, greenhouse dimming structures, and various passive thermal management components, and is particularly suitable for large-area, low-cost deployment scenarios using ordinary float soda-lime glass as a substrate.

[0078] The beneficial effects of this specific implementation method are:

[0079] This specific embodiment achieves a balance between high visible light transmittance and good solar light modulation capability in a low-cost soda-lime glass system through the synergistic design and integrated fabrication method of a "dual-functional optical matching layer".

[0080] (1) Achieve high visible light transmittance.

[0081] By introducing SiO with precisely matched refractive index x N y / AlO w N z The device employs a first and second optical matching layer of metal oxide, designed strictly according to the λ / 4 optical thickness principle. This design significantly reduces interface reflection loss, enabling the device to achieve a high average visible light transmittance T0 with only three ultra-simple three-layer film system. lum It can stably reach over 68%, and under optimized conditions, it can exceed 70%, meeting the building's lighting requirements.

[0082] (2) Achieve good long-term stability.

[0083] The high-temperature HiPIMS dense deposition of the first matching layer effectively suppressed the substrate Na+. + Ca 2+ Plasma diffusion; the low-temperature continuous coverage structure of the second matching layer effectively blocks water and oxygen permeation. After 500 hours of accelerated aging at 85℃ / 85%RH, ΔT solThe retention rate can exceed 80%, T lum The retention rate can exceed 84%, demonstrating good environmental reliability.

[0084] (3) Achieve a balance between performance and cost.

[0085] Using ordinary float soda-lime glass as the substrate, all film deposition can be completed under the unified HiPIMS platform by controlling the process window, avoiding multiple equipment conversions and complex film system superposition, and has good potential for large-scale application.

[0086] This specific implementation does not simply adopt a conventional λ / 4 antireflection film. Instead, under the dual constraints of ion diffusion and environmental sensitivity on a low-cost soda-lime glass substrate, it couples the design of refractive index range limitation, optical thickness control and deposition temperature window to achieve an intrinsic unity of optical matching and physical protection functions, thereby achieving performance improvement under simplified structural conditions.

[0087] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the oxynitride film is SiO₂. x N y or AlO w N z The SiO x N y In the condition 0 ≤ x ≤ 2, 0 ≤ y ≤ 1.33, and 3.6 ≤ 2x + 3y ≤ 4.4; the AlO w N z In the formula, 0 ≤ w ≤ 1.5, 0 ≤ z ≤ 1, and 2.7 ≤ 2w + 3z ≤ 3.3; the metal oxide film is HfO2, TiO2, ZnO, or ZrO2. Other aspects are the same as in Specific Embodiment 1.

[0088] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that λ0 = 520nm~580nm. Everything else is the same as Specific Implementation Method One or Two.

[0089] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that: ; Everything else is the same as in specific implementation methods one through three.

[0090] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that: in the W-doped VO2 nanoparticle thermochromic functional layer, W accounts for 0.2% to 2% of the total number of W and V atoms; and the average particle size of the W-doped VO2 nanoparticles in the W-doped VO2 nanoparticle thermochromic functional layer is 20 nm to 100 nm. Everything else is the same as in Specific Implementation Methods One to Four.

[0091] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that: d1 = 40nm~120nm; d3 = 60nm~150nm; and the thickness of the W-doped VO2 nanoparticle thermochromic functional layer is 30nm~120nm. Everything else is the same as Specific Implementation Methods One to Five.

[0092] Specific Implementation Method Seven: This implementation method provides a low-cost, highly transparent VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure, which is carried out according to the following steps:

[0093] 1. A first optical matching layer is deposited on a soda-lime glass substrate using reactive magnetron sputtering or high-power pulsed magnetron sputtering;

[0094] 2. A W-doped VO2 continuous thin film was deposited on the first optical matching layer by high-power pulsed magnetron sputtering and then annealed in situ to obtain a W-doped VO2 nanoparticle thermochromic functional layer.

[0095] 3. A second optical matching layer is deposited on the thermochromic functional layer of W-doped VO2 nanoparticles using reactive magnetron sputtering or high-power pulsed magnetron sputtering.

[0096] IV. Annealing, which is a low-cost, highly transparent VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure.

[0097] This specific embodiment controls the refractive index of the oxynitride film by adjusting the ratio of O2 to N2 gas during the deposition process.

[0098] The synergistic advantages of this specific implementation method for the integrated HiPIMS preparation:

[0099] A high-power pulsed magnetron sputtering (HiPIMS) integrated fabrication process is proposed, unifying the fabrication of all functional layers on a single vacuum deposition platform. HiPIMS technology boasts high peak power (up to kW / cm²). 2 Its features of high ionization rate (significantly higher than conventional DC magnetron sputtering) and independent control of ion energy and flux provide unprecedented process freedom for the precise control of multilayer film systems.

[0100] The integrated process is as follows:

[0101] Substrate pretreatment: Sodium-calcium glass is ultrasonically cleaned with acetone, ethanol, and deionized water, dried with nitrogen, and then activated with oxygen plasma to improve surface hydrophilicity.

[0102] First optical matching layer fabrication: HiPIMS technology was used to deposit dense SiO2 using Si or Al targets in an Ar / O2 / N2 mixed atmosphere via reactive sputtering, with controlled substrate temperature and pulse parameters. x Ny or AlO w N z Thin films, or those prepared using HiPIMS technology, are deposited using a high-purity metal target (99.99% purity) to form dense metal oxide films, with the thickness and refractive index controlled in real time by an optical monitoring system.

[0103] VO2 functional layer preparation: WV alloy target was used for reactive sputtering in Ar / O2 atmosphere, and after deposition, it was annealed in situ in pure Ar atmosphere to induce the formation of W-VO2 nanoparticles;

[0104] Fabrication of the second optical matching layer: By replacing the target material with Si or Al, HiPIMS deposition is performed in an Ar / O2 / N2 atmosphere, controlling the substrate temperature to obtain a continuous, low-stress, and defect-controllable oxynitride film; or HiPIMS technology is used to prepare and deposit a continuous, low-stress, and defect-controllable metal oxide film.

[0105] Post-annealing: Final annealing is carried out in an N2 or air atmosphere to eliminate interlayer stress and stabilize the microstructure and optical properties.

[0106] The core advantage of this integrated process is that by precisely controlling the substrate temperature, working pressure, pulse parameters, reaction gas ratio, and deposition time in the same equipment, three high-quality thin films can be prepared sequentially. This greatly simplifies the production process, reduces equipment investment and process conversion time costs, ensures the consistency and repeatability of the multilayer film system, and provides a clear path for the industrial application of this technology.

[0107] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method Seven in that: in step one, when the first optical matching layer is an oxynitride thin film and high-power pulsed magnetron sputtering is used to deposit the first optical matching layer on a soda-lime glass substrate, the specific steps are as follows: The target material is installed, and the following conditions are met: argon flow rate is 40 sccm~100 sccm, oxygen flow rate is 5 sccm~20 sccm, nitrogen flow rate is 5 sccm~25 sccm, working pressure is 0.3 Pa~1.0 Pa, substrate temperature is 300℃~500℃, and peak power density is 0.5 kW / cm³. 2 ~2kW / cm 2 The procedure is performed under the conditions of a pulse width of 50μs~100μs and a frequency of 200Hz~1000Hz; the target material is a Si target or an Al target. Other aspects are the same as in specific embodiment seven.

[0108] In this specific embodiment, the substrate temperature during the deposition of the first optical matching layer is 300℃~500℃ to obtain a highly dense thin film structure for suppressing substrate ion diffusion.

[0109] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method Seven or Eight in that: in step two, high-power pulsed magnetron sputtering is used to deposit a W-doped VO2 continuous thin film on the first optical matching layer, followed by in-situ annealing. Specifically, this is carried out according to the following steps: the target material is installed, and the argon flow rate is 60 sccm~120 sccm, the oxygen flow rate is 0.2 sccm~1.5 sccm, the working pressure is 0.5 Pa~1.2 Pa, the substrate temperature is 400℃~550℃, and the peak power density is 0.5 kW / cm³. 2 ~2kW / cm 2 A W-doped VO2 continuous film is deposited under pulse width of 50μs~100μs and frequency of 200Hz~1000Hz. Then, under argon flow rate of 150sccm~300sccm, the temperature is increased to 450℃~550℃ at a heating rate of 5℃ / min~20℃ / min. Finally, in-situ annealing is performed at argon flow rate of 150sccm~300sccm and temperature of 450℃~550℃ for 30min~120min to obtain a W-doped VO2 nanoparticle thermochromic functional layer. The target material is a VW alloy, and W accounts for 0.2%~2% of the total number of W and V atoms in the VW alloy. Other procedures are the same as in specific embodiments seven or eight.

[0110] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods Seven to Nine in that: in step three, when the second optical matching layer is an oxynitride thin film, and high-power pulsed magnetron sputtering is used to deposit the second optical matching layer on the W-doped VO2 nanoparticle thermochromic functional layer, the specific steps are as follows: The target material is installed, and the argon flow rate is 40 sccm~100 sccm, the oxygen flow rate is 5 sccm~20 sccm, the nitrogen flow rate is 5 sccm~20 sccm, the working pressure is 0.3 Pa~1.0 Pa, the substrate temperature is room temperature to 200℃, and the peak power density is 0.5 kW / cm². 2 ~2kW / cm 2 The process is performed under the following conditions: pulse width of 50μs~100μs and frequency of 200Hz~1000Hz; the target material is a Si target or an Al target; the annealing in step four is specifically performed under nitrogen or air atmosphere and at a temperature of 200℃~300℃ for 30min~60min. Other aspects are the same as in specific embodiments seven to nine.

[0111] The substrate temperature during deposition of the second optical matching layer in this specific embodiment is room temperature to 200°C, preferably room temperature to 150°C, in order to obtain a protective structure with continuous coverage, low stress, and limited defect channels.

[0112] The beneficial effects of the present invention are verified using the following embodiments:

[0113] Example 1:

[0114] A low-cost and highly transparent VO2 nanoparticle thermochromic smart window with a double optical matching layer structure, which consists of a soda-lime glass substrate, a first optical matching layer, a W-doped VO2 nanoparticle thermochromic functional layer, and a second optical matching layer from bottom to top;

[0115] The soda-lime glass substrate is ordinary float soda-lime glass with a size of 50mm×50mm×2mm. Under the condition of a power of 300W, it is ultrasonically cleaned in acetone, absolute ethanol, and deionized water for 15 minutes each in turn, then dried with nitrogen, and then under the conditions of a power of 100W, an oxygen atmosphere, and a working pressure of 5Pa, it is subjected to oxygen plasma treatment for 10 minutes to improve surface hydrophilicity and adhesion.

[0116] The first optical matching layer is SiO 0.50 N 1.00 ; The second optical matching layer is SiO 1.55 N 0.30 ;

[0117] Let the refractive index of the first optical matching layer at the center wavelength λ0 of visible light be n1, then n1≈1.95;

[0118] Let the refractive index of the second optical matching layer at the center wavelength λ0 of visible light be n3, then n3≈1.55;

[0119] Let the refractive index of the soda-lime glass substrate at the center wavelength λ0 of visible light be n0, and the refractive index of the W-doped VO2 nanoparticle thermochromic functional layer at the center wavelength λ0 of visible light be n2, n0≈1.5, n2≈2.70, then n0 < n1 < n2; where λ0 = 550nm;

[0120] Let the thickness of the first optical matching layer be d1, and the thickness of the second optical matching layer be d3, d1≈70nm; d3≈90nm, then the optical thickness of the first optical matching layer is n1×d1 = λ0 / 4 ± λ0 / 4×10%≈137nm, and the optical thickness of the second optical matching layer is n3×d3 = λ0 / 4 ± λ0 / 4×10%≈140nm.

[0121] ; 。

[0122] In the W-doped VO2 nanoparticle thermochromic functional layer, W accounts for 1.2% of the total number of atoms of W and V; the average particle size of the W-doped VO2 nanoparticles in the W-doped VO2 nanoparticle thermochromic functional layer is 65nm.

[0123] The thickness of the W-doped VO2 nanoparticle thermochromic functional layer is approximately 60 nm.

[0124] The above-mentioned method for preparing a low-cost, highly transparent VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure is carried out according to the following steps:

[0125] 1. Mount the calcium glass substrate into the HiPIMS system and evacuate the background vacuum to 5×10⁻⁶. -4 Pa;

[0126] II. High-power pulsed magnetron sputtering was employed, using a high-purity Si target (99.99%) as the target material, with an argon flow rate of 60 sccm, an oxygen flow rate of 8 sccm, a nitrogen flow rate of 12 sccm, a working pressure of 0.6 Pa, a substrate temperature of 350℃, and a peak power density of 1 kW / cm³. 2 A first optical matching layer was deposited on a soda-lime glass substrate under the conditions of a pulse width of 80 μs and a frequency of 500 Hz.

[0127] III. High-power pulsed magnetron sputtering was employed, using VW alloy (W comprising 1.2% of the total atomic number of W and V) as the target material, with an argon flow rate of 80 sccm, an oxygen flow rate of 0.5 sccm, a working pressure of 0.9 Pa, a substrate temperature of 500℃, and a peak power density of 1.2 kW / cm³. 2 A W-doped VO2 continuous film was deposited under conditions of pulse width of 70 μs and frequency of 400 Hz. Then, the temperature was increased to 500 ℃ at a heating rate of 10 ℃ / min under conditions of argon flow rate of 200 sccm. Finally, the film was annealed in situ for 1 h under conditions of argon flow rate of 200 sccm and temperature of 500 ℃ to obtain a W-doped VO2 nanoparticle thermochromic functional layer.

[0128] IV. High-power pulsed magnetron sputtering was employed, using a high-purity Si target (99.99%) as the target material, with an argon flow rate of 60 sccm, an oxygen flow rate of 15 sccm, a nitrogen flow rate of 5 sccm, a working pressure of 0.5 Pa, a substrate temperature of 120℃, and a peak power density of 0.8 kW / cm³. 2 Under the conditions of a pulse width of 60 μs and a frequency of 600 Hz, a second optical matching layer was deposited on the W-doped VO2 nanoparticle thermochromic functional layer.

[0129] V. A method for preparing a low-cost, highly transparent VO2 nanoparticle thermochromic smart window with a double optical matching layer structure by annealing for 1 hour under a nitrogen atmosphere and at a temperature of 250℃.

[0130] The first optical matching layer obtained under the conditions in step two of this embodiment is dense amorphous SiO₂. 0.50 N 1.00The thin film has a relative density of 95%.

[0131] The second optical matching layer obtained under the conditions in step four of this embodiment is a continuous, low-stress, and minimally defective cover layer.

[0132] Example 2: This example differs from Example 1 in that the first optical matching layer is SiO2. 0.60 N 0.93 The second optical matching layer is AlO. 1.05 N 0.3 n1≈1.92; n3≈1.65; d1≈72nm; d3≈84nm; The optical thickness of the first optical matching layer is n1×d1=λ0 / 4±λ0 / 4×10%≈138nm, and the optical thickness of the second optical matching layer is n3×d3=λ0 / 4±λ0 / 4×10%≈138nm;

[0133] In step two, during the fabrication of the first optical matching layer, the argon flow rate was 60 sccm, the oxygen flow rate was 10 sccm, and the nitrogen flow rate was 10 sccm. In step four, during the fabrication of the second optical matching layer, high-power pulsed magnetron sputtering was used, with a high-purity Al target (99.99%) as the target material. The parameters were: argon flow rate of 60 sccm, oxygen flow rate of 10 sccm, nitrogen flow rate of 15 sccm, working pressure of 0.5 Pa, substrate temperature of 100℃, and peak power density of 0.8 kW / cm³. 2 Under conditions of a pulse width of 60 μs and a frequency of 600 Hz, a second optical matching layer was deposited on the W-doped VO2 nanoparticle thermochromic functional layer. Everything else was the same as in Example 1.

[0134] Example 3: This example differs from Example 1 in that: d1≈60nm; the optical thickness of the first optical matching layer n1×d1=λ0 / 4±λ0 / 4×15%≈117nm. Everything else is the same as in Example 1.

[0135] Example 4: This example differs from Example 1 in that: d1≈80nm; the optical thickness of the first optical matching layer n1×d1=λ0 / 4±λ0 / 4×13.5%≈156nm. Everything else is the same as in Example 1.

[0136] Example 5: This example differs from Example 1 in that: both the first and second optical matching layers are HfO2; n1≈2.00; n3≈2.00; d1≈69nm; d3≈69nm; the optical thickness of the first optical matching layer is n1×d1=λ0 / 4±λ0 / 4×10%≈138nm, and the optical thickness of the second optical matching layer is n3×d3=λ0 / 4±λ0 / 4×10%≈138nm;

[0137] Step two in the preparation method is carried out as follows: high-power pulsed magnetron sputtering is used, with a high-purity Hf target (99.99%) as the target material, under conditions of argon flow rate of 60 sccm, oxygen flow rate of 10 sccm, working pressure of 0.6 Pa, substrate temperature of 350℃, and peak power density of 1 kW / cm³. 2 Deposition was carried out under conditions of a pulse width of 80 μs and a frequency of 500 Hz;

[0138] Step four in the preparation method is carried out as follows: High-power pulsed magnetron sputtering is used, with a high-purity Hf target (99.99%) as the target material, under conditions of argon flow rate of 60 sccm, oxygen flow rate of 8 sccm, working pressure of 0.5 Pa, substrate temperature of 120℃, and peak power density of 0.8 kW / cm³. 2 Deposition was performed under conditions of a pulse width of 60 μs and a frequency of 600 Hz. Other procedures were the same as in Example 1.

[0139] Comparative Experiment: This comparative experiment differs from Example 1 in that the first optical matching layer is removed. Everything else is the same as in Example 1.

[0140] (1) Visible transmittance performance test: The temperature of the device (0℃~40℃) was adjusted using a test platform equipped with a temperature control device, and its temperature-varying transmittance spectrum in the visible light band (380nm~780nm) was tested. The visible light transmittance (T) was measured. lum ), and is calculated using the following formula:

[0141] ;

[0142] Where T(λ) is the transmittance at wavelength λ, and V(λ) is the standard photometric efficiency function (CIE 1931 photometric function), which is used to represent the visual response weights of the human eye at different wavelengths.

[0143] (2) Solar Light Modulation Capability Test: Using a test platform equipped with a temperature control device, the transmittance spectrum of the device in the solar spectral band (380nm~2500nm) was tested at low temperature (0℃) and high temperature (40℃) respectively, and the solar transmittance (T) was measured. sol ), and is calculated using the following formula:

[0144] ;

[0145] Where T(λ) is the transmittance at wavelength λ, and ϕ sol (λ) represents the standard AM 1.5 solar radiation spectrum;

[0146] Solar light modulation capability (ΔT) sol ) represents T at low and high temperatures sol Difference:

[0147] ;

[0148] Among them, T sol-L T represents the solar transmittance of the device at low temperature (0°C) using the AM 1.5 solar spectrum weighted integral. sol-H The solar transmittance is obtained by weighted integration of the device at high temperature (40℃) using the AM 1.5 solar spectrum.

[0149] (3) Phase transition temperature test: Record the changes in infrared reflectance with temperature during the heating and cooling processes, and extract the reflectance of a single wavelength under different temperature conditions. Plot these values ​​to obtain the thermal hysteresis loop of the device, and perform first-order differentiation on the curve to obtain the phase transition temperature (T). MIT The formula is as follows:

[0150] ;

[0151] Among them, T heating T represents the temperature corresponding to the peak of the first-order differential curve of reflectance (or transmittance) with respect to temperature during the heating process. cooling The temperature corresponding to the peak value of the first-order differential curve of temperature during the cooling process of reflectivity (or transmittance).

[0152] (4) Environmental reliability test: The device is placed in a constant temperature and humidity test chamber and accelerated aging is performed at 85℃ / 85% relative humidity. The device is removed at regular intervals (e.g., 0, 1, 5, 10, 50 hours) and its T value is retested. lum and ΔTs ol Plot the performance degradation curve and calculate the performance retention rate.

[0153] Performance of the device prepared in Example 1: T lum =69.8%; ΔT sol =10.6%; T MIT =34.7℃; After aging at 85℃ / 85%RH for 500h: ΔT sol Retention rate = 88.5%; T lum Retention rate = 91.2%.

[0154] Performance of the device prepared in Example 2: T lum =68.9%; ΔT sol =10.4%; T MIT =34.5℃; After aging at 85℃ / 85%RH for 500h: ΔT sol Retention rate = 87.6%; T lum Retention rate = 90.6%.

[0155] Performance of the device prepared in Example 5: T lum=69.5%, ΔT sol =10.5%, T MIT =34.8℃, 85℃ / 85%RH for 500h aging: ΔT sol Retention rate = 89.0%, T lum Retention rate = 91.5%.

[0156] The performance comparison results of the devices prepared in Examples 1, 3, and 4 are shown in Table 1:

[0157] Table 1

[0158]

[0159] This indicates that there is an optimal transmittance point near a thickness of λ / 4.

[0160] Performance of devices fabricated in comparative experiments: T lum =60.5%; ΔT sol =9.7%; T MIT =35.0℃; After aging at 85℃ / 85%RH for 100h: ΔT sol Retention rate = 74%; T lum Retention rate = 82.0%. This indicates that the ion barrier layer is crucial for long-term stability.

Claims

1. A low-cost, highly transparent VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure, characterized in that... From bottom to top, it consists of a soda-lime glass substrate, a first optical matching layer, a W-doped VO2 nanoparticle thermochromic functional layer, and a second optical matching layer. Both the first optical matching layer and the second optical matching layer are oxynitride thin films or metal oxide thin films. If the refractive index of the first optical matching layer at the visible light center wavelength λ0 is n1, then 1.55≤n1≤2.40; If the refractive index of the second optical matching layer at the visible light center wavelength λ0 is n3, then 1.10≤n3≤2.20; Let the refractive index of the soda-lime glass substrate at the visible light center wavelength λ0 be n0, and the refractive index of the W-doped VO2 nanoparticle thermochromic functional layer at the visible light center wavelength λ0 be n2, then n0 <n1<n2; Let the thickness of the first optical matching layer be d1 and the thickness of the second optical matching layer be d3. Then the optical thickness of the first optical matching layer is n1×d1=λ0 / 4±λ0 / 4×30%, and the optical thickness of the second optical matching layer is n3×d3=λ0 / 4±λ0 / 4×30%.

2. The low-cost, high-transparency VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure according to claim 1, characterized in that... The oxynitride thin film is SiO x N y or AlO w N z The SiO x N y In the condition 0 ≤ x ≤ 2, 0 ≤ y ≤ 1.33, and 3.6 ≤ 2x + 3y ≤ 4.4; the AlO w N z The values ​​are 0≤w≤1.5, 0≤z≤1, and 2.7≤2w+3z≤3.3; the metal oxide film is HfO2, TiO2, ZnO or ZrO2.

3. The low-cost, high-transparency VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure according to claim 1, characterized in that... λ0 = 520nm ~ 580nm.

4. The low-cost, high-transparency VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure according to claim 1, characterized in that... ； 。 5. The low-cost, high-transparency VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure according to claim 1, characterized in that... In the W-doped VO2 nanoparticle thermochromic functional layer, W accounts for 0.2% to 2% of the total number of W and V atoms; the average particle size of the W-doped VO2 nanoparticles in the W-doped VO2 nanoparticle thermochromic functional layer is 20 nm to 100 nm.

6. The low-cost, high-transparency VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure according to claim 1, characterized in that... d1 = 40nm~120nm; d3 = 60nm~150nm; the thickness of the W-doped VO2 nanoparticle thermochromic functional layer is 30nm~120nm.

7. The method for preparing a low-cost, highly transparent VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure as described in claim 1, characterized in that... It is done in the following steps:

1. A first optical matching layer is deposited on a soda-lime glass substrate using reactive magnetron sputtering or high-power pulsed magnetron sputtering; 2. A W-doped VO2 continuous thin film was deposited on the first optical matching layer by high-power pulsed magnetron sputtering and then annealed in situ to obtain a W-doped VO2 nanoparticle thermochromic functional layer.

3. A second optical matching layer is deposited on the thermochromic functional layer of W-doped VO2 nanoparticles using reactive magnetron sputtering or high-power pulsed magnetron sputtering. IV. Annealing, which is a low-cost, highly transparent VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure.

8. The method for preparing a low-cost, highly transparent VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure according to claim 1, characterized in that... In step one, when the first optical matching layer is an oxynitride thin film and high-power pulsed magnetron sputtering is used to deposit the first optical matching layer on a soda-lime glass substrate, the specific steps are as follows: The target is installed, and the following conditions are met: argon flow rate of 40 sccm~100 sccm, oxygen flow rate of 5 sccm~20 sccm, nitrogen flow rate of 5 sccm~25 sccm, working pressure of 0.3 Pa~1.0 Pa, substrate temperature of 300℃~500℃, and peak power density of 0.5 kW / cm³. 2 ~2kW / cm 2 The pulse width is 50μs~100μs and the frequency is 200Hz~1000Hz; the target material is a Si target or an Al target.

9. The method for preparing a low-cost, highly transparent VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure according to claim 1, characterized in that... Step two involves high-power pulsed magnetron sputtering to deposit a W-doped VO2 continuous thin film on the first optical matching layer, followed by in-situ annealing. Specifically, this is performed as follows: target installation is carried out under the following conditions: argon flow rate of 60 sccm~120 sccm, oxygen flow rate of 0.2 sccm~1.5 sccm, working pressure of 0.5 Pa~1.2 Pa, substrate temperature of 400℃~550℃, and peak power density of 0.5 kW / cm³. 2 ~2kW / cm 2 A W-doped VO2 continuous film was deposited under conditions of pulse width of 50μs~100μs and frequency of 200Hz~1000Hz. Then, under conditions of argon flow rate of 150sccm~300sccm, the temperature was increased to 450℃~550℃ at a heating rate of 5℃ / min~20℃ / min. Finally, the film was annealed in situ for 30min~120min under conditions of argon flow rate of 150sccm~300sccm and temperature of 450℃~550℃ to obtain a W-doped VO2 nanoparticle thermochromic functional layer. The target material was a VW alloy, and W accounted for 0.2%~2% of the total number of W and V atoms in the VW alloy.

10. The method for preparing a low-cost, highly transparent VO2 nanoparticle thermochromic smart window with a dual optical matching layer structure according to claim 1, characterized in that... In step three, when the second optical matching layer is an oxynitride thin film and high-power pulsed magnetron sputtering is used to deposit the second optical matching layer on the W-doped VO2 nanoparticle thermochromic functional layer, the specific steps are as follows: The target is installed, and the following conditions are met: argon flow rate of 40 sccm~100 sccm, oxygen flow rate of 5 sccm~20 sccm, nitrogen flow rate of 5 sccm~20 sccm, working pressure of 0.3 Pa~1.0 Pa, substrate temperature of room temperature to 200℃, and peak power density of 0.5 kW / cm³. 2 ~2kW / cm 2 The process is performed under the conditions of a pulse width of 50μs~100μs and a frequency of 200Hz~1000Hz; the target material is a Si target or an Al target; the annealing in step four is specifically performed under the conditions of nitrogen or air atmosphere and temperature of 200℃~300℃ for annealing for 30min~60min.

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