High-transmission reconfigurable optical thin film based on perovskite phase change material

Abstract

The invention belongs to the field of optical thin films, and particularly relates to a high-transmission reconfigurable optical thin film based on a perovskite phase change material. The optical thin film comprises a first metal layer, a first transparent dielectric layer, a perovskite phase change material functional layer, a second transparent dielectric layer, a second metal layer and a top transparent dielectric layer from bottom to top to form an F-P resonant cavity structure. Based on the low-temperature-phase low-loss characteristic of a perovskite material and the resonance enhancement effect of an F-P cavity, the resonance wavelength and transmission intensity of the resonant cavity can be dynamically regulated and controlled by changing the thickness or the phase state of the perovskite functional layer, so that the full-color-gamut coverage and gray adjustment from blue to red in a visible light range are realized. The film has the advantages of high transmissivity, high color purity, non-volatile phase change, high switching speed, large-area preparation, good cycling stability and the like, and is suitable for the fields of intelligent windows, dynamic filtering display, high-resolution optical patterning and the like.

Description

Technical Field

[0001] This application belongs to the field of optical thin films, and more specifically, relates to a high-transmission reconfigurable optical thin film based on perovskite phase change material. Background Technology

[0002] Structural color originates from the interaction between light and the periodic micro- and nano-structures on the surface of an object. It modulates light propagation through interference, diffraction, and scattering, ultimately acting on the visual nerves to form color perception. Compared to chemical colors formed by traditional dyes, structural colors possess advantages such as high saturation, high brightness, high resolution, resistance to fading, and environmental friendliness. Among these, structural color schemes based on Fabry-Perot (FP) resonant cavity resonance have attracted significant attention due to their high color purity and strong design flexibility, and are considered to have application potential in fields such as light-filtering displays, anti-counterfeiting, and smart windows.

[0003] To endow optical thin-film devices with reconfigurable and dynamically color-changing properties, existing technologies attempt to integrate functional materials such as hydrogels, vanadium dioxide, and chalcogenide phase change materials into reconfigurable devices as functional layers. However, the optical thin-film devices fabricated in this way have significant defects in overall performance, making it difficult to meet the needs of practical applications. Optical thin films based on hydrogel materials have slow response speeds (often on the order of seconds or even minutes), poor environmental stability, and their swelling / shrinkage physical mechanisms are not well compatible with micro- and nano-scale FP cavity structures, making it difficult to achieve large-area uniform and reliable performance.

[0004] Vanadium dioxide (VO2)-based optical thin films exhibit volatile phase transition properties, meaning they spontaneously revert to an insulating state after the removal of an external heat source, restoring their optical properties. This prevents VO2-based devices from maintaining their intended color or transparency, limiting their use in non-volatile applications requiring long-term, stable display of patterns or tones (such as static filters and persistent display elements).

[0005] Optical thin films based on chalcogenide phase change materials (such as Ge2Sb2Se4Te1) can achieve non-volatile phase transitions, but due to the high intrinsic optical loss (large extinction coefficient) of chalcogenide materials across the entire visible light spectrum, the overall transmittance of optical thin films made from them is relatively low (typically peak transmittance <30%). This makes the devices appear dim in the "on" state, making it difficult to achieve the required high transmittance and thus unsuitable for scenarios with stringent requirements for high light transmittance, such as smart windows and high-brightness displays.

[0006] Therefore, there is a need to develop a non-volatile optical thin film that has high transmittance to visible light waves, can generate high-purity, tunable structural colors, and maintains high-contrast switching. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the purpose of this application is to provide a high-transmittance reconfigurable optical thin film based on perovskite phase change materials. This aims to solve the problem of low transmittance caused by high optical loss in the visible light band of existing optical thin films, as well as the difficulty in simultaneously achieving non-volatility, fast response, and high color purity control.

[0008] To achieve the above objectives, in a first aspect, this application provides a high-transmission reconfigurable optical thin film based on perovskite phase change material, which is provided from bottom to top as follows: a first metal layer, a first transparent dielectric layer, a perovskite phase change material functional layer, a second transparent dielectric layer, a second metal layer, and a top transparent dielectric layer. The perovskite phase change materials mentioned above exhibit reversible phase change characteristics between the low-temperature phase and the high-temperature phase, and both the refractive index and the extinction coefficient change before and after the phase change. The first metal reflective layer, the first transparent dielectric layer, the second transparent dielectric layer, and the second metal reflective layer together constitute a Fabry-Perot resonant cavity. The optical parameters within the resonant cavity are changed by the phase transition of the perovskite phase change material functional layer, thereby dynamically controlling the transmission spectrum of the optical thin film.

[0009] Preferably, the first transparent dielectric layer and the second transparent dielectric layer are used to physically isolate the perovskite phase change material functional layer from the metal layer.

[0010] Preferably, by adjusting the thickness of the perovskite phase change material functional layer or switching it between a low-temperature phase and a high-temperature phase, the peak wavelength and intensity of the peak in the transmission spectrum can be changed, thereby achieving the display of different colors and grayscale.

[0011] Preferably, the material of the functional layer of the perovskite phase change material is at least one of CsPbCl3, CsPbBr3, and CsPbI3.

[0012] Preferably, the thickness of the functional layer of the perovskite phase change material is 50 nm to 150 nm.

[0013] Preferably, the phase transition of the functional layer of the perovskite phase change material is achieved by laser direct writing or thermal annealing.

[0014] Preferably, the first and second metal layers are made of silver and have a thickness of 10 nm to 20 nm.

[0015] Preferably, the materials of the first transparent dielectric layer and the second transparent dielectric layer are each independently indium tin oxide, aluminum oxide or silicon dioxide, and the thickness is 60nm~120nm.

[0016] Preferably, the material of the aforementioned top transparent dielectric layer is indium tin oxide or silicon dioxide, and the thickness is 80nm~140nm.

[0017] Secondly, this application provides a light-filtering display device or smart window that includes the aforementioned high-transmittance reconfigurable optical thin film.

[0018] In summary, the technical solutions conceived in this application have the following main technical advantages compared with the prior art: (1) The high-transmittance reconfigurable optical thin film provided in this application selects perovskite phase change material as phase change functional layer and designs the structure of optical thin film device in a coordinated manner. Based on the low loss of perovskite material in low temperature phase and the resonance enhancement effect of FP cavity, the device can achieve a peak transmittance of up to 80% in the "on state" (low temperature phase). At the same time, the high contrast and reversible switching of the transmission state can be achieved through phase change, which significantly improves the light transmittance performance and dynamic tuning capability of optical thin film in the visible light region.

[0019] (2) By precisely designing and controlling the thickness of each film layer, such as the phase change functional layer, the transparent dielectric layer, and the metal layer, this application can effectively modulate the resonant wavelength of the FP cavity, achieving full color gamut coverage from blue to red in the visible light range, and obtaining high color purity. Furthermore, by changing the thickness of the perovskite phase change material functional layer, dynamic switching of different colors or gray levels can be achieved at the same device location.

[0020] (3) This application utilizes the non-volatile phase transition characteristics of perovskite materials to enable the optical state of the device to be maintained for a long time after the phase transition, overcoming the defect that devices based on volatile phase transition materials such as VO2 cannot maintain the set state. At the same time, combined with localized external excitation methods such as laser direct writing, it is possible to realize rapid phase transition in micro-areas, providing a new technical path for high-resolution color dynamic display, reconfigurable optical patterns and information storage.

[0021] (4) This application effectively isolates the perovskite functional layer and the metal layer through a unique transparent dielectric layer structure design, suppresses the interface reaction and diffusion during the high-temperature phase transition process, and improves the interface stability and reliability of the device during long-term cyclic use.

[0022] (5) The film materials selected in this application are all compatible with standard semiconductor thin film preparation processes such as magnetron sputtering and thermal co-evaporation, which is conducive to achieving large-area, uniform and low-cost manufacturing. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the high-transmission reconfigurable optical thin film based on perovskite phase change material provided in this application; Figure 2 This is the refractive index of the perovskite phase change material used in this application; Figure 3 This is the extinction coefficient of the perovskite phase change material used in this application; Figure 4 This is the transmission spectrum of the optical thin film provided in Embodiment 1 of this application when the perovskite phase change material functional layer is a low-temperature phase; Figure 5 This is the transmission spectrum chromaticity diagram of the optical thin film provided in Embodiment 1 of this application when the perovskite phase change material functional layer is a low-temperature phase; Figure 6 This is the transmission spectrum of the optical thin film provided in Embodiment 2 of this application; Figure 7 This is the transmission spectral chromaticity diagram of the optical thin film provided in Embodiment 2 of this application; Figure 8 This is the transmission spectrum of the optical thin film provided in Embodiment 3 of this application; Figure 9 This is the transmission spectral chromaticity diagram of the optical thin film provided in Embodiment 3 of this application; Figure 10 This is the transmission spectrum of the optical thin film provided in Embodiment 4 of this application; Figure 11 This is the transmission spectral colorimetric diagram of the optical thin film provided in Embodiment 4 of this application. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0025] In the specification and claims of this application, the terms “first” and “second” are used to distinguish different objects, rather than to describe a specific order of objects, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0026] In the description of the embodiments in this application, the words "exemplary" or "for example" are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design options. Specifically, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0027] In the description of the embodiments in this application, unless otherwise stated, "multiple" means two or more.

[0028] In recent years, perovskite materials have been extensively studied in the optoelectronic field. However, existing research has largely focused on their use as light-absorbing layers in solar cells, light-emitting layers in LEDs, or functional materials in electrochromic devices, primarily aiming to improve their photoelectric conversion efficiency, luminescence quantum yield, and device stability. However, systematic research is still lacking on how perovskite materials, as the core functional layer of reconfigurable optical thin films, particularly the evolution of their optical constants (n, k) before and after phase transition, can produce beneficial synergistic effects with FP cavities containing metal reflective layers and multilayer dielectric films. Achieving high transmittance background while obtaining high-purity, tunable structural colors and maintaining high contrast switching remains an underexplored area. This application innovatively utilizes perovskite materials as a phase-change functional layer and co-designs the structure of optical thin-film devices, providing a reconfigurable optical thin film with high transmittance and high performance.

[0029] Specifically, the high-transmittance reconfigurable optical thin film based on perovskite phase change material provided in this application has the following structure: Figure 1 As shown, from bottom to top, it includes: a first metal layer, a first transparent dielectric layer, a perovskite phase change material functional layer, a second transparent dielectric layer, a second metal layer, and a top transparent dielectric layer; The perovskite phase change materials mentioned above exhibit reversible phase change characteristics between the low-temperature phase and the high-temperature phase, and both the refractive index and the extinction coefficient change before and after the phase change. The first metal reflective layer, the first transparent dielectric layer, the second transparent dielectric layer, and the second metal reflective layer together constitute a Fabry-Perot resonant cavity (FP cavity). The optical parameters within the resonant cavity are changed by the phase transition of the perovskite phase change material functional layer, thereby dynamically controlling the transmission spectrum of the optical thin film.

[0030] The high-transmittance reconfigurable optical thin film based on perovskite phase change material provided in this application is a Fabry-Pérot resonator constructed using nano-optics. The basic principle is to select specific wavelengths of light by utilizing the interference effect formed by multiple reflections of light between two mirrors. By changing the resonant wavelength of the FP resonator, specific colors are generated, achieving full color gamut coverage in the visible light band. As a transmissive optical thin film, the material grown on a transparent substrate consists of six layers, from bottom to top: a first metal layer, a first transparent dielectric layer, a perovskite phase change material functional layer, a second transparent dielectric layer, a second metal layer, and a top transparent dielectric layer. The first metal layer, acting as the bottom mirror of the FP resonator, has high reflectivity, causing light to reflect multiple times within the cavity, enhancing the interference effect and increasing the intensity of the transmitted beam. The first transparent dielectric layer plays a role in adjusting the cavity length; by changing its thickness or refractive index, the resonant wavelength of the resonator can be adjusted, while also possessing good transparency to reduce light absorption and scattering. The perovskite phase change material functional layer undergoes a phase transition through changes in laser power or temperature, thereby altering its refractive index and extinction coefficient. This significantly changes the overall transmittance of the film, allowing for dynamic adjustment of the resonant wavelength of the resonant cavity, enabling reconfigurable optical thin films. The second transparent dielectric layer also functions to adjust the cavity length; by changing its thickness, the resonant wavelength can be adjusted, achieving color modulation. Simultaneously, it provides isolation and protection, preventing reactions between the perovskite layer and the metal under high-temperature conditions. The second metal layer, acting as the top reflector of the FP resonant cavity, also possesses high reflectivity. Working together with the first metal layer, it creates multiple reflections, enhancing the interference effect. This enhanced interference effect contributes to achieving a narrower full width at half maximum (FWHM) and better color purity. The top transparent dielectric layer protects the entire film, preventing the underlying layers from being corroded by environmental factors (such as oxygen and moisture), thus maintaining the long-term stability of the resonant cavity.

[0031] In some embodiments, by adjusting the thickness of the perovskite phase change material functional layer or switching it between a low-temperature phase and a high-temperature phase, the peak wavelength and intensity of the peak in the transmission spectrum can be changed, thereby achieving the display of different colors and grayscale.

[0032] In some embodiments, the material of the perovskite phase change material functional layer is at least one of CsPbCl3, CsPbBr3, and CsPbI3. The refractive index (n) and extinction coefficient (k) of CsPbI3 are as follows: Figure 2 , Figure 3As shown, perovskite phase change materials exhibit low extinction coefficients and low optical losses in the visible light range. High-transmittance reconfigurable optical thin films constructed based on this perovskite phase change material achieve high transmittance in the visible light range compared to existing optical thin films, while also exhibiting significant optical contrast before and after the phase transition, strong optical modulation capabilities, and the ability to adjust different colors and grayscale levels. In some embodiments, the thickness of the functional layer of the aforementioned perovskite phase change material is 50 nm to 150 nm.

[0033] In some embodiments, the phase transition of the functional layer of the perovskite phase change material is achieved through laser direct writing or thermal annealing. For example, laser direct writing can be used to heat a small area; when the laser power reaches a certain intensity, the perovskite film undergoes a transition from a low-temperature phase to a high-temperature phase. Alternatively, an annealing furnace can be used to anneal the entire film; when the temperature reaches a certain condition, the perovskite film undergoes a transition from a low-temperature phase to a high-temperature phase.

[0034] In some embodiments, the first and second metal layers are made of silver. The inventors have experimentally discovered that, compared to FP cavity optical films with metal layers made of conductive, highly reflective metals such as copper or aluminum, optical films with metal layers made of silver can produce higher contrast before and after the phase transition of the perovskite phase change material functional layer. In some embodiments, the thicknesses of the first and second metal layers are each independently 10 nm to 25 nm, which increases the full width at half maximum (FWHM) of the optical film's transmission peak and improves the overall transmittance of the film.

[0035] In some embodiments, the materials of the first and second transparent dielectric layers are independently indium tin oxide, aluminum oxide, or silicon dioxide, and their thicknesses are independently 60 nm to 120 nm. The first and second transparent dielectric layers in this application can isolate the metal layer from the perovskite phase change material functional layer, preventing a reaction between the metal layer and the perovskite phase change material functional layer under high-temperature conditions, while not affecting the regulatory function of the perovskite phase change material functional layer.

[0036] In some embodiments, the material of the aforementioned top transparent dielectric layer is silicon dioxide, with a thickness of 80nm~140nm. The top transparent dielectric layer in this application can play an antioxidant role, preventing the metal layer from being corroded by moisture and oxygen in the air, which helps to achieve the long-term stability of the resonator, while not affecting the interference phase of light or heat conduction.

[0037] It is understood that this application does not limit the technology for preparing the above-mentioned optical thin film. For example, the first transparent dielectric layer, the second transparent dielectric layer, and the top transparent dielectric layer can be grown using magnetron sputtering or physical vapor deposition; the first metal layer and the second metal layer can be deposited using magnetron sputtering; and the perovskite phase change material functional layer can be obtained by thermal co-evaporation deposition. It should be noted that the above preparation process must be carried out under a protective atmosphere such as argon, helium, neon, or krypton.

[0038] On the other hand, this application also provides a display device or smart window that includes the aforementioned high-transmittance reconfigurable optical thin film.

[0039] It should be understood that materials of the same or similar type, model, quality, properties, or function as the reagents and instruments used in the following embodiments can be used to implement this application. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Unless otherwise specified, the materials and reagents used in the following embodiments are commercially available.

[0040] The following is an example: Example 1 This embodiment provides a high-transmittance reconfigurable optical thin film based on perovskite phase change material, the structure of which is as follows: a first metal layer (Ag), a first transparent dielectric layer (SiO2), a perovskite phase change material functional layer (CsPbI3), a second transparent dielectric layer (SiO2), a second metal layer (Ag), and a top transparent dielectric layer (SiO2) are sequentially disposed on a transparent substrate (SiO2) from bottom to top. The thickness of the first and second metal layers is 20 nm, the thickness of the first and second transparent dielectric layers is 70 nm, the thickness of the top transparent dielectric layer is 100 nm, and the thicknesses of the perovskite phase change material functional layers are sequentially set to 70, 90, 110, 130, and 150 nm.

[0041] Transmission spectra of the optical thin films with perovskite phase change material functional layers of different thicknesses were obtained using Essential Macleod simulation software. Figure 4 (Transmission spectrum) It can be seen that when the perovskite phase change material functional layer is in the low temperature phase, the peak transmittance of the optical thin film of the perovskite phase change material functional layer of different thicknesses is greater than 50%, which shows high transmittance.

[0042] The transmitted light spectrum was processed into a chromaticity diagram (using the CIE 1931 standard chromaticity system) using Origin's Chromaticity Diagram module. Figure 5(Transmission colorimetric diagram) It can be seen that when the perovskite phase change material functional layer is in the low-temperature phase, by adjusting the thickness of the perovskite phase change material functional layer, the optical thin film can exhibit different transmission colors and achieve full color gamut transmission in the visible light band, realizing dynamic switching of transmission colors.

[0043] Example 2 This embodiment provides a high-transmittance reconfigurable optical thin film based on perovskite phase change material with the same structure as in Embodiment 1. The thicknesses of the first metal layer (Ag), the first transparent dielectric layer (SiO2), the perovskite phase change material functional layer (CsPbI3), the second transparent dielectric layer (SiO2), the second metal layer (Ag), and the top transparent dielectric layer (SiO2) from bottom to top are 15nm, 60nm, 80nm, 60nm, 15nm, and 100nm, respectively.

[0044] The transmission spectrum of the high-transmission reconfigurable optical thin film provided in this embodiment was calculated using Essential Macleod simulation software. Figure 6 The simulated transmission spectrum was then imported into Origin's Chromaticity Diagram module and processed into a chromaticity diagram according to the CIE 1931 standard chromaticity system. Figure 7 ).

[0045] like Figure 6 As shown, when the functional layer of the perovskite phase change material is in the low-temperature phase, the peak transmittance reaches 55%, with a peak wavelength of 475 nm. Figure 7 The mid-chromaticity coordinates indicate the blue region, meaning the film exhibits a blue transmission color. When the perovskite phase change material functional layer transforms into the high-temperature phase, the overall transmittance of the film is below 10%, and the film exhibits an "off state." This demonstrates that high-contrast switching of the transmission state is achieved by controlling the phase state of the perovskite phase change material functional layer.

[0046] Example 3 The structure of the high-transmittance reconfigurable optical thin film based on perovskite phase change material provided in this embodiment is the same as that in Embodiment 1. The thicknesses of the first metal layer (Ag), the first transparent dielectric layer (SiO2), the perovskite phase change material functional layer (CsPbI3), the second transparent dielectric layer (SiO2), the second metal layer (Ag), and the top transparent dielectric layer (SiO2) from bottom to top are 20nm, 80nm, 100nm, 80nm, 20nm, and 100nm, respectively.

[0047] The transmission spectrum of the high-transmission reconfigurable optical thin film provided in this embodiment was calculated using Essential Macleod simulation software. Figure 8The simulated transmission spectrum was then imported into Origin's Chromaticity Diagram module and processed into a chromaticity diagram according to the CIE 1931 standard chromaticity system. Figure 9 ).

[0048] like Figure 8 As shown, when the functional layer of the perovskite phase change material is in the low-temperature phase, the peak transmittance reaches 80%, with a peak wavelength of 550 nm. Figure 9 The chromaticity coordinates indicate a green region, meaning the film exhibits a green transmission color. When the perovskite phase change material functional layer transitions to a high-temperature phase, the overall transmittance of the film is below 10%, and the film exhibits an "off state." This demonstrates that high-contrast switching of the transmission state is achieved by controlling the phase state of the perovskite phase change material functional layer.

[0049] Example 4 The structure of the high-transmittance reconfigurable optical thin film based on perovskite phase change material provided in this embodiment is the same as that in Embodiment 1. The thicknesses of the first metal layer (Ag), the first transparent dielectric layer (SiO2), the perovskite phase change material functional layer (CsPbI3), the second transparent dielectric layer (SiO2), the second metal layer (Ag), and the top transparent dielectric layer (SiO2) from bottom to top are 25nm, 70nm, 150nm, 70nm, 25nm, and 100nm, respectively.

[0050] The transmission spectrum of the high-transmission reconfigurable optical thin film provided in this embodiment was calculated using Essential Macleod simulation software. Figure 10 The simulated transmission spectrum was then imported into Origin's Chromaticity Diagram module and processed into a chromaticity diagram according to the CIE 1931 standard chromaticity system. Figure 11 ).

[0051] like Figure 10 As shown, when the functional layer of the perovskite phase change material is in the low-temperature phase, the peak transmittance reaches 80%, with a peak wavelength of 650 nm. Figure 11 The mid-chromaticity coordinates are in the red-orange region, indicating that the film exhibits a red-orange transmission color. When the perovskite phase change material functional layer transforms into the high-temperature phase, the overall transmittance of the film is only 12%, and the film exhibits an "off state." This demonstrates that high-contrast switching of the transmission state is achieved by controlling the phase state of the perovskite phase change material functional layer.

[0052] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A high-transmittance reconfigurable optical thin film based on perovskite phase change material, characterized in that, The structure consists of, from bottom to top, a first metal layer, a first transparent dielectric layer, a perovskite phase change material functional layer, a second transparent dielectric layer, a second metal layer, and a top transparent dielectric layer. The perovskite phase change material exhibits reversible phase change characteristics between a low-temperature phase and a high-temperature phase, and both the refractive index and extinction coefficient change before and after the phase change. The first metal reflective layer, the first transparent dielectric layer, the second transparent dielectric layer, and the second metal reflective layer together constitute a Fabry-Perot resonant cavity. The optical parameters within the resonant cavity are changed by the phase change of the perovskite phase change material functional layer, thereby dynamically controlling the transmission spectrum of the optical thin film.

2. The high-transmittance reconfigurable optical thin film according to claim 1, characterized in that, The first transparent dielectric layer and the second transparent dielectric layer are used to physically isolate the perovskite phase change material functional layer from the metal layer.

3. The high-transmittance reconfigurable optical thin film according to claim 1 or 2, characterized in that, By adjusting the thickness of the functional layer of the perovskite phase change material, or by switching it between a low-temperature phase and a high-temperature phase, the peak wavelength and intensity of the peak in the transmission spectrum can be changed, thereby achieving the display of different colors and grayscale.

4. The high-transmittance reconfigurable optical thin film according to claim 3, characterized in that, The material of the perovskite phase change material functional layer is at least one of CsPbCl3, CsPbBr3, and CsPbI3.

5. The high-transmittance reconfigurable optical thin film according to claim 3, characterized in that, The thickness of the functional layer of the perovskite phase change material is 50 nm to 150 nm.

6. The high-transmittance reconfigurable optical thin film according to claim 3, characterized in that, The phase transition of the functional layer of the perovskite phase change material is achieved by laser direct writing or thermal annealing.

7. The high-transmittance reconfigurable optical thin film according to claim 1, characterized in that, The first and second metal layers are made of silver and have a thickness of 10 nm to 20 nm.

8. The high-transmittance reconfigurable optical thin film according to claim 1, characterized in that, The first and second transparent dielectric layers are each made of indium tin oxide, aluminum oxide, or silicon dioxide, and have a thickness of 60 nm to 120 nm.

9. The high-transmittance reconfigurable optical thin film according to claim 1, characterized in that, The material of the top transparent dielectric layer is indium tin oxide or silicon dioxide, and the thickness is 80nm~140nm.

10. A light-filtering display device or smart window, characterized in that, It includes a high-transmittance reconfigurable optical thin film as described in any one of claims 1 to 9.

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