Ion-protected electrochromic device and its forming method thereof

Abstract

An Ion-protected electrochromic device and its forming method thereof are provided, comprising a substrate and multiple stacked structures disposed on the substrate. Each stacked structure includes an ion-conducting protective layer, an electrochromic layer and a metal electrode layer. By adopting the metal electrode layer as an absorption film to absorb an incident light and the electrochromic effect provided by the electrochromic layer, the proposed electrochromic device is able to switch between least two various reflectivities and colors. During the electrochromic process, the ion-conducting protective layer provides a pathway for ion transport, preventing ions from penetrating the electrochromic layer and causing erosion damage, thereby offering protective functionality. This invention does not require the use of traditional ITO transparent conductive films, instead opting for metal materials as electrodes, thereby effectively solving the issue of ITO material supply shortages.

Description

[Technical Field]

[0001] This invention relates to an ion-protected electrochromic device and its forming method, particularly an ion-protected electrochromic device and its forming method that has process advantages and does not require the use of traditional transparent conductive films. [Previous Technology]

[0002] Electrochromism technology has been developing since the 1960s and has a history of nearly 60 years. Generally speaking, electrochromism refers to the stable and reversible change in the optical properties (such as reflectivity, transmittance, absorptivity, etc.) of a material under an applied voltage, causing its appearance to switch between color and transparency.

[0003] For example, the coloring and bleaching processes of electrochromic materials involve applying a voltage across a transparent conductive layer to cause ions to migrate into or out of the electrochromic layer, thereby changing the valence of the electrochromic material and resulting in a color change. When the system reaches equilibrium, the color change tends to stabilize. In recent years, electrochromic materials have shown great potential and broad application prospects due to their advantages such as low driving voltage, bistable nature, and tunability. Furthermore, technological trends are gradually moving towards high-safety solid-state electrolytic layers and colloidal electrochromic materials.

[0004] However, existing electrochromic technologies mostly use transparent conductive layers, such as indium tin oxide (ITO) films, as electrode materials. Although ITO has excellent conductivity and transparency and is the most common transparent conductive material, it still suffers from drawbacks such as material shortages, high process costs, and poor mechanical properties. Indium (In) is a rare resource, and its large-scale use has led to supply shortages and a significant price increase, resulting in high material costs. In addition, ITO cannot achieve good photoelectric properties through wet processing; it requires high-temperature baking or expensive sputtering processes, further increasing manufacturing costs. On the other hand, ITO is an inorganic brittle material with poor ductility, limiting its application in flexible electronic products and affecting conductivity and reliability.

[0005] Based on the above problems, the industry urgently needs new solutions. Therefore, based on years of research experience, in-depth observation and theoretical application, the inventors have proposed a novel ion-protected electrochromic device and its formation method, which can effectively replace ITO material, solve its long-standing technical defects, and provide a more cost-effective and application-valued architecture and process. The specific technical content and implementation method will be detailed later. [Summary of the Invention]

[0006] In order to solve the problems existing in the prior art, one object of the present invention is to provide an ion-protected electrochromic device that combines electrochromic technology with black film technology of optical thin film, so that the formed ion-protected electrochromic device can switch between two or more reflectivity spectra and colors.

[0007] Another objective of this invention is to provide an ion-protected electrochromic device and its formation method, which eliminates the need for traditional ITO transparent conductive films and instead uses metal materials as electrodes. This not only effectively solves the problem of ITO material shortage but also makes the manufacturing process simpler and more efficient compared to existing technologies. Furthermore, during the electrochromic process, the ion-conducting protective layer provides a pathway for ions to pass through, preventing ions from entering the electrochromic layer and causing corrosion damage, thereby protecting the electrochromic layer, improving the durability and stability of the device, and reducing maintenance costs.

[0008] To achieve the above objectives, the present invention provides an ion-protected electrochromic device, comprising: a substrate and a plurality of stacked structures disposed on the substrate, wherein each stacked structure includes an ion-conducting protective layer, an electrochromic layer, and a metal electrode layer. In each stacked structure, the ion-conducting protective layer is located on the electrochromic layer, and the electrochromic layer is located on the metal electrode layer, and is disposed on the substrate through direct contact with the bottommost metal electrode layer. The metal electrode layer absorbs incident light, and through the electrochromic effect of the electrochromic layer, the ion-protected electrochromic device generates two or more reflectivities and colors, and can switch between these reflectivities and colors. During the electrochromic process, the ion-conducting protective layer provides an ion passage path and protects the electrochromic layer.

[0009] On the other hand, the present invention provides a method for forming an ion-protected electrochromic device, the steps of which include: providing a substrate; and forming a plurality of stacked structures on the substrate, wherein each stacked structure includes an ion-conducting protective layer, an electrochromic layer and a metal electrode layer, wherein the ion-conducting protective layer in each stacked structure is located on the electrochromic layer, the electrochromic layer is located on the metal electrode layer, and is disposed on the substrate through direct contact with the bottom metal electrode layer, wherein the metal electrode layer absorbs an incident light, and through the electrochromic effect of the electrochromic layer, the ion-protected electrochromic device generates two or more reflectivities and colors, and can switch between the reflectivities and colors, and during the electrochromic process, the ion-conducting protective layer provides an ion passage path and protects the electrochromic layer.

[0010] According to an embodiment of the present invention, the material of the ion-conducting protective layer is tantalum pentoxide (Ta2O5).

[0011] According to an embodiment of the present invention, the electrochromic layer is made of tungsten trioxide (WO3), titanium dioxide (TiO2), molybdenum oxide (MoO3), nickel oxide (NiO), vanadium pentoxide (V2O5), or a combination thereof.

[0012] According to an embodiment of the present invention, the metal electrode layer is made of tungsten (W) or tantalum (Ta).

[0013] According to an embodiment of the present invention, the reflectivity is between 2% and 9%.

[0014] According to an embodiment of the present invention, the colors include blue and black.

[0015] According to an embodiment of the present invention, the ion-conducting protective layer is made of tantalum pentoxide (Ta2O5), the electrochromic layer is made of tungsten trioxide (WO3), and the metal electrode layer is made of tantalum (Ta). Therefore, the present invention can directly use the tantalum metal electrode layer as an absorption film, which absorbs incident light. Then, by utilizing electrochromic technology, the optical constant of the electrochromic layer is changed, thereby altering the reflectivity and color of the absorption film of the ion-protected electrochromic device.

[0016] According to a preferred embodiment of the present invention, the refractive index that can be changed and switched includes, for example, an average refractive index of around 3.3% in the spectral range of 400 to 700 nanometers (nm), at which point the ion-protected electrochromic device exhibits a bleached blue state. Subsequently, the optical constant of the electrochromic layer is changed using electrochromic technology, thereby changing the reflectivity and color of the absorption film, for example, an average refractive index of around 2.5% in the spectral range of 400 to 700 nanometers (nm), at which point the ion-protected electrochromic device exhibits a colored black state.

[0017] In view of the above, the ion-protected electrochromic device and its formation method provided by the present invention can switch between two or more reflectivity spectra and colors in response to different application requirements, while the absorption film still has the characteristics of low reflectance and high absorption.

[0018] The applicant will further explain the present invention in detail below with reference to specific embodiments and accompanying drawings, so that it will be easier to understand the purpose, technical content, features and effects achieved by the present invention.

Implementation Method

[0019] The above description of the present invention, along with the following embodiments, is used to demonstrate and explain the spirit and principles of the present invention, and to provide a further explanation of the scope of the patent application. The features, implementation, and effects of the present invention are described in detail below with reference to the accompanying drawings.

[0020] In particular, with reference to preferred embodiments of the present invention, examples are shown in the drawings, and in the drawings and description, the present invention uses the same graphic symbols to refer to the same or similar elements as much as possible.

[0021] Existing electrochromic device structures mostly use ITO transparent conductive films as their electrode materials. Although theoretically they have good conductivity and transparency, the materials themselves are still scarce, difficult to obtain, and expensive. Therefore, in order to effectively improve the long-standing deficiencies of the existing technology, the present invention discloses a novel ion-protected electrochromic device and its formation method. The embodiments provided below are intended to clarify the main technical content and features of the present invention, and to enable those skilled in the art to understand, manufacture, and use the present invention. However, it should be noted that the following embodiments are not intended to limit the scope of the invention. Therefore, any equivalent modifications or variations thereof according to the spirit of the present invention should also be covered within the scope of the invention, and are therefore described in advance.

[0022] Please refer to Figure 1, which is a schematic diagram of the structure of an ion-protected electrochromic device according to an embodiment of the present invention. The ion-protected electrochromic device 1 provided by the present invention includes a substrate 100 and a plurality of stacked combination structures 200 formed on the substrate 100, wherein each stacked combination structure 200 includes an ion-conducting protective layer 20C, an electrochromic layer 20A, and a metal electrode layer 20B. In the embodiment shown in Figure 1, two stacked combination structures 200 are provided on the substrate 100 as an exemplary example, but the present invention is not limited thereto. In other words, those skilled in the art can naturally make appropriate modifications or changes to the technical solutions disclosed in the present invention without departing from the spirit of the present invention. For example, providing three or more stacked combination structures 200 on the substrate 100 should still fall within the scope of the present invention. The present invention is not limited to the structural connection methods and the number of structures shown in the exemplary example.

[0023] In an embodiment of the present invention, the ion-conducting protective layer 20C is preferably made of tantalum pentoxide (Ta2O5); the electrochromic layer 20A is preferably an electrochromic thin film, the material of which includes, but is not limited to, tungsten trioxide (WO3), titanium dioxide (TiO2), molybdenum oxide (MoO3), nickel oxide (NiO), vanadium pentoxide (V2O5), or a combination thereof; the metal electrode layer 20B is preferably a metal thin film, the material of which may be tungsten (W) or tantalum (Ta). As shown in the figure, in each stacked combination structure 200, the ion-conducting protective layer 20C is located on the electrochromic layer 20A, the electrochromic layer 20A is located on the metal electrode layer 20B, and is directly contacted by the bottom metal electrode layer 20B in the stacked combination structure 200 to be disposed on the substrate 100.

[0024] Please refer to Figure 2, which illustrates a method for forming an ion-protected electrochromic device 1 according to an embodiment of the present invention. This method includes steps S221 to S223. As shown in step S221, a substrate 100 is first provided, which may be, for example, a B270 glass substrate. Next, as shown in step S223, the stacked assembly structures 200 are sequentially deposited and formed on the substrate 100. Each stacked assembly structure 200 includes an ion-conducting protective layer 20C, an electrochromic layer 20A, and a metal electrode layer 20B. In each stacked assembly structure 200, the ion-conducting protective layer 20C is located on the electrochromic layer 20A, and the electrochromic layer 20A is located on the metal electrode layer 20B, and is directly contacted by the bottommost metal electrode layer 20B of the stacked assembly structure 200 to be disposed on the substrate 100. In one embodiment of the present invention, the ion conduction protective layer is a tantalum pentoxide (Ta2O5) thin film, the electrochromic layer is a tungsten trioxide (WO3) thin film, and the metal electrode layer is a tantalum (Ta) metal thin film.

[0025] In detail, this embodiment uses a high-vacuum DC magnetron sputtering system. First, a 66.5 nm thick tantalum metal thin film is deposited on the substrate 100 as a metal electrode layer 20B, and the tantalum metal thin film is used as an absorption film to absorb incident light. Then, multiple thin films are deposited on the absorption film, forming a stacked structure from top to bottom: ion conduction protective layer 20C (Ta2O5, 23.7 nm), electrochromic layer 20A (WO3, 31.7 nm), metal electrode layer 20B (Ta, 16.3 nm), ion conduction protective layer 20C (Ta2O5, 16.9 nm), electrochromic layer 20A (WO3, 20.9 nm), metal electrode layer 20B (Ta, 66.5 nm), and substrate 100.

[0026] Thus, the present invention can directly use a tantalum metal thin film as an absorption film to absorb incident light, and deposit a multilayer film combination on it. Each film layer includes an ion-conducting protective layer, an electrochromic layer, and a metal electrode layer, so that the absorption film exhibits a preset reflectivity and color. For example, in the spectral range of 400 to 700 nm, its average reflectivity is about 3.3%, and its average absorptivity is about 96.7%, exhibiting a blue color. Furthermore, by adjusting the optical constants of the electrochromic thin film through electrochromic technology, the reflectivity and color of the absorption film can be changed. For example, in the spectral range of 400 to 700 nm, the average reflectivity can be reduced to about 2.5%, and the average absorptivity can be increased to about 97.5%, exhibiting a black color. The present invention maintains the low reflectivity and high absorption characteristics of the absorption film while achieving two different reflectivity and color switching through an electrochromic mechanism to adapt to different application requirements.

[0027] Furthermore, during the electrochromic process, the ion-conducting protective layer not only provides ion transport channels, facilitating the smooth entry of ions into the electrochromic layer, but also reduces the erosion damage to the film during ion entry, minimizing void formation and thus protecting the structural integrity of the electrochromic layer. It is worth mentioning that this invention eliminates the need for an ITO transparent conductive film, effectively avoiding the problem of a gradual shortage of ITO materials.

[0028] In addition, in order to further enhance the color-changing effect of the electrochromic layer, in a preferred embodiment of the present invention, the outer electrochromic film can be thickened to improve its color-changing effect.

[0029] In view of this structure, the present invention can enable the ion-protected electrochromic device to have two or more reflectivities and colors through the electrochromic effect of the electrochromic layer, and can switch between different reflectivities and colors.

[0030] Please refer to Figure 3, which is a reflection spectrum data diagram of the ion-protected electrochromic device 1 according to Figure 1 of the present invention in the colored and decolorized states. The solid line shows the decolorized state reflection spectrum measured after the actual plating of the ion-protected electrochromic device 1, and the dashed line shows the colored state reflection spectrum measured after electrochromization of the ion-protected electrochromic device 1. It can be clearly seen from these data that when the spectral range of the incident light is between 400 and 700 nm, the average reflectance of the ion-protected electrochromic device 1 is around 3.3%, which is the decolorized state and presents a blue color, as shown by the solid line in Figure 3.

[0031] Next, lithium perchlorate (LiClO4) with an electrolyte of 0.1M was mixed with anhydrous propylene carbonate. The black film element of this ion-protected electrochromic device 1 was then placed in the solution, and a negative 5-volt voltage was applied. This caused lithium ions to migrate into the WO3 film of the electrochromic layer after passing through the Ta₂O₅ film, resulting in a change in the optical constant of the WO3 film. The reflectance spectrum measured under these conditions is shown by the dashed line in Figure 3. At this time, the ion-protected electrochromic device 1 is in a colored state. When the incident light spectrum is between 400 and 700 nm, the average reflectance of the ion-protected electrochromic device 1 is around 2.5%, and it appears black.

[0032] Figure 4 shows a comparison image of the electrochromic black film provided by the present invention before (upper side) and after (lower side) color change. It can be seen that the area U1 on the upper side of the glass shows the actual black film element, which appears blue; while in contrast, the area D1 on the lower side of the glass is the colored state of the black film element, which appears black.

[0033] Therefore, based on the data and images provided in Figures 3 and 4, it can be effectively verified that the ion-protected electrochromic device and its formation method provided by the present invention can not only successfully deposit black film elements and adjust their reflectivity and color, but also switch between two or more reflectivity spectra and colors to meet different application requirements while the absorption film still has the characteristics of low reflectivity and high absorption. Furthermore, in the ion-protected electrochromic device of the present invention, the ion-conducting protective layer can provide ion transport channels, effectively preventing ions from causing erosion damage when entering the electrochromic layer, thereby protecting the electrochromic layer structure, improving the durability and stability of the device, and reducing maintenance costs.

[0034] On the other hand, the present invention also proposes a technical solution to increase the thickness of the outer electrochromic layer, thereby further increasing the color-changing effect of the electrochromic technology. In addition, considering the shortage of existing ITO transparent conductive film materials year by year, the present invention also improves this deficiency, and does not require the use of traditional ITO transparent conductive film, but directly uses metal materials as its electrodes, which is simpler, more convenient and cheaper in terms of process.

[0035] In summary, the present invention mainly provides an innovative ion-protected electrochromic device and its formation method. Compared with the prior art, the absorption film of the present invention still possesses the characteristics of low reflectance and high absorption, and can realize two or more reflectance spectra and colors according to application requirements, and switch between them, thereby expanding its application potential in the solar energy, semiconductor, and power electronics industries. On the other hand, the present invention provides a stable ion transport channel through an ion conduction protective layer, effectively reducing the corrosive effect of ions on the electrochromic layer, thereby improving the durability and stability of the device, while reducing maintenance costs. In this way, the present invention is not only applicable to the above-mentioned industries, but can also be widely used in various color display technology fields, demonstrating superior industrial value and competitiveness.

[0036] At the same time, the applicant has also verified through various experimental data and empirical data that the technical features, methods and means disclosed in this invention are significantly different from the existing solutions. They are not something that can be easily accomplished by someone with ordinary knowledge in the technical field of this invention, and should meet the requirements for patent.

[0037] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above. Therefore, the scope of protection of the present invention should be defined by the appended claims. [Simplified Explanation of the Diagram]

[0038] Figure 1 is a structural schematic diagram of an ion-protected electrochromic device according to an embodiment of the present invention. Figure 2 is a flowchart of the steps of forming an ion-protected electrochromic device according to an embodiment of the present invention. Figure 3 is a reflection spectrum data diagram of the ion-protected electrochromic device of Figure 1 according to the present invention in the colored state and the decolored state. Figure 4 is a schematic diagram of a comparison image of the electrochromic black film provided by the present invention before and after color change.

Claims

1. An ion-protected electrochromic device, comprising: One substrate; The device comprises a plurality of stacked structures formed on the substrate, wherein each stacked structure includes an ion-conducting protective layer, an electrochromic layer, and a metal electrode layer. The metal electrode layer is made of tungsten (W) or tantalum (Ta). In each stacked structure, the ion-conducting protective layer is located on the electrochromic layer, and the electrochromic layer is located on the metal electrode layer, and is disposed on the substrate through direct contact with the bottom metal electrode layer. The metal electrode layer absorbs incident light and, through the electrochromic effect of the electrochromic layer, enables the ion-protected electrochromic device to generate two or more reflectivities and colors, and can switch between these reflectivities and colors. During the electrochromic process, the ion-conducting protective layer provides an ion passage path and protects the electrochromic layer.

2. The ion-protected electrochromic device as described in claim 1, wherein the material of the ion-conducting protective layer is tantalum pentoxide (Ta2O5).

3. The ion-protected electrochromic device as described in claim 1, wherein the electrochromic layer is made of tungsten trioxide (WO3), titanium dioxide (TiO2), molybdenum oxide (MoO3), nickel oxide (NiO), vanadium pentoxide (V2O5), or a combination thereof.

4. The ion-protected electrochromic device as described in claim 1, wherein the ion-conducting protective layer is made of tantalum pentoxide (Ta2O5), the electrochromic layer is made of tungsten trioxide (WO3), and the metal electrode layer is made of tantalum (Ta).

5. The ion-protected electrochromic device as described in claim 1, wherein the reflectivity is between 2% and 9%.

6. The ion-protected electrochromic device as described in claim 1, wherein the colors include blue and black.

7. A method for forming an ion-protected electrochromic device, comprising the following steps: A substrate is provided; and a plurality of stacked structures are formed on the substrate, wherein each stacked structure includes an ion-conducting protective layer, an electrochromic layer and a metal electrode layer, the metal electrode layer being made of tungsten (W) or tantalum (Ta), the ion-conducting protective layer in each stacked structure being located on the electrochromic layer, the electrochromic layer being located on the metal electrode layer and being disposed on the substrate through direct contact with the bottom metal electrode layer, the metal electrode layer absorbing an incident light, and through the electrochromic effect of the electrochromic layer, the ion-protected electrochromic device generating two or more reflectivities and colors, and being able to switch between these reflectivities and colors, and during the electrochromic process, the ion-conducting protective layer providing an ion passage path and protecting the electrochromic layer.

8. The method for forming an ion-protected electrochromic device as described in claim 7, wherein the material of the ion-conducting protective layer is tantalum pentoxide (Ta2O5).

9. A method for forming an ion-protected electrochromic device as described in claim 7, wherein the electrochromic layer is made of tungsten trioxide (WO3), titanium dioxide (TiO2), molybdenum oxide (MoO3), nickel oxide (NiO), vanadium pentoxide (V2O5), or a combination thereof.

10. A method for forming an ion-protected electrochromic device as described in claim 7, wherein the ion-conducting protective layer is made of tantalum pentoxide (Ta2O5), the electrochromic layer is made of tungsten trioxide (WO3), and the metal electrode layer is made of tantalum (Ta).

11. The method for forming an ion-protected electrochromic device as described in claim 7, wherein the reflectivity is between 2% and 9%.

12. A method for forming an ion-protected electrochromic device as described in claim 7, wherein the colors include blue and black.

Images