Full-color reversible electro-controlled color-changing device, its fabrication method and application

Abstract

This invention discloses a full-color reversible switchable electro-controlled color-changing device, its preparation method, and its applications. The electro-controlled color-changing device includes a color-changing layer, an electrolyte, and a counter electrode. The color-changing layer includes a substrate, a conductive layer, and an active material layer, with the active material layer and the conductive layer forming physical interference colors. The electrolyte is in contact with the conductive layer or the active material layer; when an electrochemical reaction occurs between the electrolyte and the surface of the conductive layer or the active material layer, the thickness of the active material layer changes. The electro-controlled color-changing device provided by this invention offers a rich range of adjustable colors, covering the entire color gamut, and achieves reversible color switching under low voltage. Furthermore, the colors regulated by the electro-controlled color-changing device provided by this invention have memory characteristics, maintaining the color without additional energy input, making it energy-saving and environmentally friendly. It also features high brightness and high saturation, showing broad application prospects in energy-saving displays, decoration, anti-counterfeiting, and batteries.

Description

Technical Field

[0001] This invention relates to the field of optical technology, and in particular to a full-color reversible switchable electrically controlled color-changing device, its preparation method and application. Background Technology

[0002] With the development of the times and the advancement of technology, electronic displays have become an integral part of our daily lives. Therefore, energy-saving technology for electronic displays is particularly important in green and environmentally friendly projects.

[0003] Traditional electronic display devices, such as LED or more traditional LCD and rear projection displays, must use a continuous supply of electrical energy to maintain the display of patterns or colors. Once the power supply is lost, the ability to display patterns or colors will be lost for a short period of time.

[0004] For some fields that do not require dynamic display of patterns or colors, such as billboards and signs, the switching of patterns or colors is not frequent. Constantly consuming electricity to maintain the display of patterns or colors obviously generates a lot of unnecessary energy waste, which is not conducive to green, environmentally friendly and sustainable development.

[0005] Some existing technologies attempt to solve the above problems. For example, some existing technologies represented by Chinese invention patent CN1426543A provide a certain electrodeposition type display device that can realize the electrical control of pattern and color changes. After the color changes, there is no need to continue to consume electrical energy to maintain the pattern or color. However, some of the technical solutions provided by these existing technologies can only realize black and white pattern changes, or changes of a single color or a few colors. They cannot realize multi-color control of a wide color gamut. In essence, they are still a pattern display device, rather than a multi-color control device.

[0006] Other existing technical solutions, such as Chinese invention patents CN113296328A or CN112117442A, can only obtain a film layer with multiple basic colors through film layer design, and then adjust the color and / or transparency of the film layer appropriately by applying voltage. The color change is still around the basic color, or it is just a change in brightness or transparency, or even just a change in color temperature. Its essence is still a local adjustment around the basic color, and it cannot achieve a wide color gamut adjustment on a single material.

[0007] In summary, the existing electro-controlled color-changing structures or devices cannot meet the current demand for diverse and wide color gamut adjustment in electronic displays, and their application effects are not ideal. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a full-color reversible switchable electrically controlled color-changing device, its preparation method, and its application.

[0009] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0010] In a first aspect, the present invention provides a full-color reversible switchable electro-controlled color-changing device, comprising a color-changing layer and an electrolyte;

[0011] The color-changing layer includes a substrate, a conductive layer, and an active material layer. The active material layer and the conductive layer form physical interference to obtain structural color.

[0012] The electrolyte is in contact with the conductive layer or the active material layer. When the electrolyte undergoes an electrochemical reaction with the surface of the conductive layer or the active material layer, the thickness of the active material layer changes.

[0013] Secondly, the present invention also provides a method for preparing an electrically regulated color-changing device, comprising:

[0014] A conductive layer is formed on the substrate;

[0015] The electrolyte is brought into contact with the conductive layer, and an active material layer is formed between the electrolyte and the conductive layer by electrochemical deposition to form an electro-controlled color-changing device.

[0016] Alternatively, an active material layer can be formed on the surface of the conductive layer, and then the electrolyte can be brought into contact with the active material layer to form an electrically regulated color-changing device;

[0017] When the electrolyte undergoes an electrochemical reaction with the surface of the conductive layer or the active material layer, the thickness of the active material layer changes.

[0018] Based on the above technical solution, compared with the prior art, the beneficial effects of the present invention include at least the following:

[0019] The electro-regulating color-changing device provided by this invention offers a rich selection of adjustable colors, covering the entire color gamut, and enables reversible color switching under low voltage, with a voltage window of less than 6V. Furthermore, the colors regulated by the electro-regulating color-changing device provided by this invention have memory characteristics, maintaining the color without additional energy input, thus being energy-saving and environmentally friendly. It also features high brightness and high saturation, making it a promising candidate for applications in energy-saving displays, decoration, anti-counterfeiting, and batteries.

[0020] The above description is merely an overview of the technical solution of the present invention. In order to enable those skilled in the art to better understand the technical means of this application and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described below in conjunction with detailed drawings. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of an electrically regulated color-changing device provided in a typical embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of an electrically regulated color-changing device provided in another typical embodiment of the present invention;

[0023] Figure 3 This is a typical embodiment of the present invention, showing the reflectance curve and the variation law of the active material layer thickness of the electro-controlled color-changing device.

[0024] Figure 4 This is a photograph of the electro-regulating color-changing process of the electro-regulating color-changing device provided in a typical embodiment of the present invention;

[0025] Figure 5 This is a photograph of the electro-controlled color-changing behavior of the electro-controlled color-changing device under different hydrogen ion concentrations, provided in another typical embodiment of the present invention.

[0026] Figure 6 This is a photograph showing the electro-regulating color-changing behavior of the electro-regulating color-changing device under different electrolyte contents, provided in another typical embodiment of the present invention. Detailed Implementation

[0027] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The following will further explain and illustrate this technical solution, its implementation process, and its principles.

[0028] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0029] This invention provides a method for fabricating a device that enables reversible switching between multiple colors through electrical control. It is applicable to various static display scenarios. By applying a small voltage externally, the device achieves switching between multiple colors. Due to its memory retention characteristics, no additional energy is required to maintain the display for a long time, thus satisfying people's needs for color while achieving energy saving.

[0030] Therefore, this invention provides a full-color reversible switchable electro-controlled color-changing device, including a color-changing layer and an electrolyte; the color-changing layer includes a substrate, a conductive layer and an active material layer, the active material layer and the conductive layer forming a physical interference color; the electrolyte is in contact with the conductive layer or the active material layer, and when the electrolyte reacts with the surface of the conductive layer or the active material layer, the thickness of the active material layer changes.

[0031] Some existing technologies provide a solution such as an electrochromic electrode based on electrochromic materials that responds to voltage. However, these technologies all rely on the color-changing principle of metal ion insertion / extraction to control the color in response to voltage, thereby achieving the indication function. However, this color-changing principle is still based on the local adjustment of the basic color of the electrochromic material itself. Even though these existing technologies have achieved a variety of basic colors through film design, the subsequent electrochromic range is not wide, and it is impossible to achieve diverse color changes on a single device.

[0032] This invention creatively employs electro-thickness control to directly change the interference parameters of the optical interference structure, thereby enabling full-gamut color electro-controllable changes on a single device. Furthermore, the main electro-control condition based on this invention is the duration of voltage application or the amount of electricity passing through the electrolytic reaction. These are the most direct variables determining the thickness parameters, rather than relying on voltage-controlled ion insertion and extraction trends as in existing technologies.

[0033] In some embodiments, the electro-controlled color-changing device may further include a counter electrode electrically connected to the electrolyte. For ease of application, a counter electrode may be provided within the device; however, it may also be omitted, and the electrolyte may be connected via electrodes or electrical contact components during use.

[0034] In some implementation schemes, it is possible to, for example Figure 1 As shown, the counter electrode and the color-changing layer are stacked along the thickness direction or as shown in the figure. Figure 2 As shown, the counter electrode and the color-changing layer are arranged side by side along the width direction; when arranged side by side, it is also called "side by side". At this time, some non-transparent counter electrodes can be used. On the one hand, the selection range of counter electrodes is expanded. On the other hand, non-transparent counter electrodes can often be selected as more dense and stable electrodes, such as bulk metals or carbon materials, which can obtain a more stable device structure.

[0035] In some embodiments, the counter electrode is transparent or translucent, primarily to achieve, Figure 1 The electrode and the color-changing layer shown are preferably stacked, such as a metal mesh or a metal film, and are also made of transparent or semi-transparent materials.

[0036] The materials of the counter electrode include, but are not limited to: metals (such as Zn, Ag, Cu, Au, Fe, Ti, V, Pt, W, Pd, etc.), oxides, nitrides, sulfides, carbon materials (such as carbon cloth, carbon fiber, carbon nanotube film, graphene film, etc.), conductive polymers, etc.

[0037] The substrate can be glass, plexiglass, plastic products, fiber, carbon material film, fabric, wood board, ceramic or metal alloy, building exterior wall, etc. In this invention, there are no specific restrictions on the material of the substrate, as long as it can effectively support the conductive layer.

[0038] In some embodiments, the electrolyte contains a variety of cations.

[0039] In some embodiments, the electrolyte contains at least two colored metal ions.

[0040] In some embodiments, the cations in the electrolyte include H+. + Li + Al 3+ Na + K + 、Rb + Ag + Ni 2 + Ca 2+ Mo 6+ Mn 2+ Ti 4+ V 4+ Zn 2+ W 6+ Ta 5+ Cu 2+ Bi 3+ Sn 4+ Mg 2+ Cs + Any one or more combinations of the above-mentioned cations, but not limited to the range of cations listed above.

[0041] Preferably, the electrolyte may contain a zinc salt compound.

[0042] In some embodiments, the zinc salt compound may include, for example, any one or a combination of two or more of Zn(ClO4)2, Zn(NO3)2, ZnSO4, ZnCl2 or Zn(Ac)2.

[0043] In some embodiments, the electrolyte may be in liquid, gel, or solid state.

[0044] Specifically, the solute in the electrolyte may be, for example, H+. + Li + Al 3+ Na + K + 、Rb + Ag + Ni 2+ Ca 2+ Mo6+ Mn 2+ Ti 4+ V 4+ Zn 2+ W 6+ Ta 5+ Cu 2+ Bi 3+ Sn 4+ Mg 2+ or Cs + The electrolyte layer may contain zinc salt compounds, such as Zn(ClO4)2, Zn(NO3)2, ZnSO4, ZnCl2, or Zn(Ac)2, depending on the polarity of the applied voltage. Ions contained in the electrolyte can undergo insertion / extraction, deposition / dissolution, or deposition phenomena in the color-changing layer, contributing to the color change or light transmittance variation of the device. In some embodiments, the electrolyte used contains a mixture of multiple ions, which, compared to a single ion, allows for richer and more vibrant color changes and better stability of the device.

[0045] In some implementations, the active material layer is made of any one or a combination of two or more of metal oxides, metals, and polymers.

[0046] In some embodiments, the active material layer is made of any one or more of the following: ZnO, MnO2, MoO3, WO3, Fe3O4, Fe2O3, NiO, VO2, V2O5, TiO2, CuO, Cu2O, Al2O3, Ta2O5, Ag2O, Ag, Cu, Al, Ni, Zn, Bi, Au, Pt, polyaniline, polythiophene, and polypyrrole. Specifically, the active material can be selected from metal oxides, metals, or polymers, such as ZnO, MnO2, MoO3, WO3, Fe3O4, Fe2O3, NiO, VO2, V2O5, TiO2, CuO, Cu2O, Al2O3, Ta2O5, Ag2O, Ag, Cu, Al, Ni, Zn, Bi, Au, Pt, polyaniline, polythiophene, and polypyrrole.

[0047] Furthermore, the active material layer can be a single layer, for example, it can be formed directly by an electrolyte through an electrodeposition reaction. Specifically, it can be formed by plating one or more metals, especially non-ferrous metals, on the surface of the conductive layer. The active material layer formed in this way is often a single layer. Alternatively, a metal oxide can be deposited on the surface of the conductive layer as a seed layer (which can be regarded as a sublayer of the active material layer), and then a metal or polymer layer is electrodeposited through an electrolyte (forming a second sublayer), thereby obtaining an active material layer with a double-layer structure.

[0048] Therefore, in some possible embodiments, the active material layer may include a first sublayer and a second sublayer stacked together, the first sublayer being in close contact with the conductive layer. The first sublayer may include the aforementioned metal oxide, and the second sublayer may include the aforementioned metal and / or polymer. This embodiment, due to the presence of a seed layer, exhibits good electrodeposition uniformity, fine grains, faster color-changing response, and more stable color maintenance performance. Because of the seed layer, the growth process of the active material eliminates the nucleation stage, directly initiating growth, resulting in more uniform and faster growth, thus leading to a faster color-changing response and more uniform full-color color-changing performance.

[0049] In some embodiments, the material of the conductive layer may include any one or a combination of two of the following: metals and non-metallic conductive materials.

[0050] In some embodiments, the material of the conductive layer may include any one or more combinations of Cu, Ag, W, Ti, V, Fe, Cr, Ni, Zn, Al, Mo, Au, Pd, Co, Ta, Pt, Mg, carbon materials, conductive metal oxides, and conductive polymer materials, and is not limited thereto. Specifically, the conductive layer may be selected from metals or other conductive materials. Metal materials include, but are not limited to, Cu, Ag, W, Ti, V, Fe, Cr, Ni, Zn, Al, Mo, Au, Pd, Co, Ta, Pt, Mg, etc., and conductive materials include, but are not limited to, carbon materials (e.g., carbon cloth, carbon fiber, carbon nanotube film, graphene film, etc.), metal oxides (e.g., AZO, ITO, FTO), and other conductive polymer materials (e.g., polyaniline, polyacetylene), etc.

[0051] In some implementations, the structure of the conductive layer is any one of a one-dimensional thin film, a two-dimensional photonic crystal, a three-dimensional photonic crystal, or nanoparticles.

[0052] In some implementations, the thickness of the conductive layer is preferably 0-1 cm, and more preferably 50-1000 nm in the following embodiments.

[0053] In some implementations, the structure of the active material layer can be any one of a one-dimensional thin film, a two-dimensional photonic crystal, a three-dimensional photonic crystal, or nanoparticles.

[0054] In some embodiments, the thickness of the active material layer is 0-1 mm, preferably 0-800 nm, and more preferably 0-200 nm. It should be noted that the thickness of the active material layer can be 0, which can be understood as the active material layer not yet existing. For example, in the following embodiments, the state after electrolyte injection but before electrodeposition begins. In this case, the device still has the intrinsic color of the conductive layer and still falls within the scope of the electro-controlled color-changing device described in this invention. It is not limited to the formation of an active material layer to qualify as a color-changing device of this invention. That is, the existence of the active material layer is related to the state of electro-control. In the initial state, or when reversibly restored to the initial state after cyclic color changing, the active material layer may not exist (the point-controlled color-changing device includes a selectively active material layer), i.e., its thickness is 0.

[0055] Accordingly, a second aspect of the present invention also provides a method for preparing an electrically regulated color-changing device, comprising the following steps:

[0056] A conductive layer is formed on the substrate.

[0057] The electrolyte is brought into contact with the conductive layer, and an active material layer is formed between the electrolyte and the conductive layer through electrochemical deposition, thus forming an electro-controlled color-changing device.

[0058] Alternatively, an active material layer can be formed on the surface of the conductive layer, and then the electrolyte can be brought into contact with the active material layer to form an electrically regulated color-changing device.

[0059] When the electrolyte undergoes an electrochemical reaction with the surface of the conductive layer or the active material layer, the thickness of the active material layer changes.

[0060] As some typical implementation examples of the above technical solutions, the preparation method provided by the present invention can be implemented by the following steps:

[0061] The color-changing layer is obtained by physical or chemical deposition. A conductive layer is deposited on the substrate. The conductive layer can be a metal, metal oxide, nitride, sulfide, carbon material or conductive polymer. Then, an active material can be selectively deposited on the conductive layer by physical or chemical deposition. The thickness of the active material layer can be selected between 0-800 nm.

[0062] The color-changing layer and the counter electrode are assembled face-to-face or side-by-side, and the two electrodes are connected by an electrolyte. The electrolyte can be in liquid, gel, or solid form. The electrolyte can be a mixed electrolyte, such as a mixed electrolyte composed of two or more salts from aqueous salts such as ZnCl2, H2SO4, MnSO4, MnCl2, and ZnSO4.

[0063] An active material layer is deposited or dissolved on the conductive or color-changing layer by means of electrochemistry. Different thicknesses of the active material layer correspond to different device colors, thereby obtaining devices with multiple colors that can be reversibly switched.

[0064] A third aspect of this invention also provides a color control method for an electrically regulated color-changing device, comprising the following steps:

[0065] Provide an electrically regulated color-changing device according to any of the above embodiments.

[0066] A voltage is applied between the conductive layer and the electrolyte, and by adjusting the application time of the applied voltage, the electro-controlled color-changing device can exhibit different colors.

[0067] In some implementations, the color control method further includes:

[0068] By applying a reverse voltage between the conductive layer and the electrolyte, the color exhibited by the electro-controlled color-changing device can be reversibly restored.

[0069] In some implementations, the applied voltage is below 6V, preferably 1.2-2V.

[0070] In some implementations, the application time is 0-160 seconds.

[0071] In some implementations, by adjusting the application time, the electrochromic device can display any one of the colors red, orange, yellow, green, blue, indigo, and violet, thus achieving full color. Of course, the full color referred to in this invention also means the ability to control and produce at least seven of these colors within a single device. This wide color gamut is unattainable by existing technologies that use color changes in electrochromic materials to achieve localized color changes.

[0072] The fourth aspect of the present invention also provides the application of the electro-controlled color-changing device provided in any of the above embodiments in any of the fields of display, decoration, anti-counterfeiting, batteries, and energy-saving building materials.

[0073] The technical solution of the present invention will be further described in detail below through several embodiments and in conjunction with the accompanying drawings. However, the selected embodiments are only for illustrating the present invention and do not limit the scope of the present invention.

[0074] Example 1

[0075] This embodiment illustrates a device for reversibly switching between multiple colors through electrical control, including a color-changing layer (substrate, conductive layer, active material layer), an electrolyte, and a counter electrode layer. Its structure is described in [reference needed]. Figure 1 As shown.

[0076] The fabrication method of the device that enables reversible switching of multiple colors through electrical control in this embodiment is as follows: A conductive layer is deposited on a clean PET plastic plate, specifically: an AZO film with a thickness of 200 nm is magnetron sputtered; a transparent Cu metal mesh is used as the counter electrode; a liquid electrolyte containing multiple cations is injected between the two electrodes: Cu 2+ Mn 2+ H + Bi 3+ The working electrode (conductive layer) and the counter electrode are respectively connected to the two poles of the electrochemical workstation. Given a voltage, preferably 1.2V, by applying different voltages for different durations to the device, active materials of different thicknesses are formed on the conductive layer and the application time of the voltage is controlled to obtain a device with multiple color changes. Furthermore, when the opposite current is applied, the color change is reversibly restored in the same way. The electro-controlled color-changing device provided by this invention realizes the reversible switching of seven full colors in the same device by controlling the application time of the voltage.

[0077] Of course, the aforementioned conductive AZO film can also be prepared using methods known in the industry, such as electron beam evaporation and thermal evaporation, and the resulting color change effect is the same.

[0078] Example 2

[0079] This embodiment illustrates a device for reversibly switching between multiple colors through electrical control, including a color-changing layer (substrate, conductive layer, active material layer), an electrolyte, and a counter electrode layer. See [link to documentation]. Figure 1 As shown.

[0080] The fabrication method of the device that enables reversible switching of multiple colors through electro-regulation in this embodiment is as follows: A conductive layer is deposited on a clean glass substrate. Preferably, an Au film with a thickness of 50 nm is magnetron sputtered. ITO is selected as the counter electrode, and a transparent ITO with a thickness of 200 nm is chosen. An electrolyte is injected between the two electrodes, and PVA is added to the electrolyte as a framework to form a gel with a PVA content of 20%. The working electrode and the counter electrode are respectively connected to the two poles of an electrochemical workstation. A voltage is applied, preferably 2V. By applying different voltages to the device for different times, active materials of different thicknesses are obtained on the conductive layer, resulting in a device with multiple color changes. The color change range still covers seven full colors and is stable and reversible.

[0081] Of course, the aforementioned conductive Au and ITO films can also be prepared using methods known in the industry, such as electron beam evaporation and thermal evaporation, and the resulting color change effect is the same.

[0082] Example 3

[0083] This embodiment illustrates a device for reversibly switching between multiple colors through electrical control, including a color-changing layer (substrate, conductive layer, active material layer), an electrolyte, and a counter electrode layer. See [link to documentation]. Figure 1 As shown.

[0084] The fabrication method of the device for reversibly switching multiple colors through electro-control in this embodiment is as follows: A conductive layer is deposited on a clean carbon nanotube film; preferably, a polyaniline film with a thickness of 1 μm is screen-printed; then, a layer of MnO2 with a thickness of 100 nm is electrochemically deposited on the polyaniline film as one of the active material layers; the counter electrode is made of metallic Zn; preferably, a transparent Zn metal mesh is selected; a liquid electrolyte is injected between the two electrodes; preferably, the liquid electrolyte contains multiple cations: Zn 2+ Mn 2+ H + The monomer, crosslinking agent, and photoinitiator are used for UV curing to obtain a hydrogel electrolyte. The working electrode and the counter electrode are respectively connected to the two poles of the electrochemical workstation. A given voltage is applied, preferably 1.8V. By applying different voltages for different times to the device, active materials of different thicknesses are obtained on the conductive layer, resulting in a variety of color-changing devices. The color change range still covers seven full colors and is stable and reversible.

[0085] Of course, the aforementioned conductive polyaniline film can also be prepared using known methods in the industry, such as electrochemical deposition and spin coating, and the resulting color change effect is the same.

[0086] Furthermore, in this embodiment, the thickness of the deposited manganese dioxide corresponds one-to-one with its color; the corresponding color can be obtained by changing the deposition thickness. For example, a thickness of 130 nm corresponds to yellow, and a thickness of 210 nm corresponds to green, etc.

[0087] Example 4

[0088] This embodiment illustrates a device that achieves reversible switching of multiple colors through electrical control, including a color-changing layer (substrate, conductive layer, active material layer), an electrolyte, and a counter electrode layer, assembled into a device side-by-side. See [link to documentation]. Figure 2 As shown. Reflectance curves and optical photographs of individual devices at different active material layer thicknesses can be found in [reference needed]. Figure 3 and Figure 4 As shown.

[0089] The fabrication method of the device that achieves reversible switching of multiple colors through electro-regulation in this embodiment is as follows: A conductive layer is deposited on a clean PET transparent film, preferably, a layer of Pt is magnetron sputtered, with a preferred Pt thickness of 80 nm; a carbon nanotube film is used as the counter electrode, and the devices are assembled side-by-side; a liquid electrolyte is injected between the two electrodes, preferably containing multiple components: Cr(NO3)3, MnCl2, HCl, monomers, crosslinking agents, and photoinitiators for UV curing to obtain a hydrogel electrolyte; the working electrode and the counter electrode are respectively connected to the two poles of an electrochemical workstation, and a voltage is applied, preferably 1.8V. By applying different voltages for different times to the device, active materials of different thicknesses are obtained on the conductive layer, resulting in devices with multiple color changes, such as... Figure 3 and Figure 4 As shown, the thickness of a typical active material layer can be 0-200nm. Within this range, its color variation still covers seven full colors and is stable and reversible.

[0090] Of course, the aforementioned conductive Pt film can also be prepared using methods known in the industry, such as electron beam evaporation and thermal evaporation, and the resulting color change effect is the same.

[0091] Example 5

[0092] This embodiment illustrates a device that achieves reversible switching of multiple colors through electrical control, including a color-changing layer (substrate, conductive layer, active material layer), an electrolyte, and a counter electrode layer, assembled into a device side-by-side. See [link to documentation]. Figure 2 As shown. Optical photographs of a single device at different H+ concentrations can be found in [reference needed]. Figure 5 .

[0093] The fabrication method of the device for reversibly switching multiple colors through electro-regulation in this embodiment is as follows: A conductive layer is deposited on a clean PET transparent film. Preferably, an ITO layer is magnetron sputtered, with a preferred ITO thickness of 200 nm. A carbon nanotube film is used as the counter electrode, and the devices are assembled side-by-side. A liquid electrolyte is injected between the two electrodes. Preferably, the liquid electrolyte contains multiple components: BiCl3, ZnCl2, HCl, monomers, crosslinking agents, and photoinitiators for UV curing to obtain a hydrogel electrolyte. The working electrode and the counter electrode are connected to the two poles of an electrochemical workstation. A voltage is applied, preferably 1.5V. By changing the hydrogen ion concentration in the device electrolyte, the response time of the color change is controlled, and active materials of different thicknesses are obtained on the conductive layer to obtain devices with multiple color changes. Simultaneously, devices with different hydrogen ion concentrations are fabricated, and their color-changing patterns are as follows: Figure 5 As shown, the hydrogen ion concentration in the range of 100-160mM has no effect on whether full-color performance can be achieved; the main effect is on the speed of color change.

[0094] Of course, the aforementioned conductive ITO film can also be prepared using known methods in the industry, such as electron beam evaporation and thermal evaporation, and the resulting color change effect and the influence of hydrogen ion concentration are the same.

[0095] Example 6

[0096] This embodiment 6 discloses a device for reversibly switching multiple colors through electrical control, comprising a color-changing layer (substrate, conductive layer, active material layer), an electrolyte, and a counter electrode layer, assembled into a device in a side-by-side manner. See [link to documentation]. Figure 2 As shown. Optical photographs of a single device at different total ion concentrations can be found in [reference needed]. Figure 6 As shown.

[0097] The fabrication method of the device for reversibly switching multiple colors through electro-regulation in this embodiment is as follows: A conductive layer is deposited on a clean transparent glass substrate, preferably by magnetron sputtering of a layer of Ag with a thickness of 200 nm; a Pt sheet is used as the counter electrode, and the devices are assembled side-by-side; a liquid electrolyte is injected between the two electrodes, preferably containing multiple components: CuCl2, ZnCl2, and H2SO4; the working electrode and the counter electrode are connected to the two poles of an electrochemical workstation, respectively, and a voltage is applied, preferably 1.5V. The response time of the color change is controlled by changing the ion concentration in the electrolyte of the device, and active materials of different thicknesses are obtained on the conductive layer to obtain devices with multiple color changes. By fabricating devices with multiple ion concentrations, it was found that the ion concentration in the range of 0.1-0.5M still has no significant effect on the color change range, but mainly affects the color change speed.

[0098] Of course, the aforementioned conductive Ag film can also be prepared using known methods in the industry, such as electron beam evaporation and thermal evaporation, and the resulting color change effect and the influence of total ion concentration are the same.

[0099] Based on the above embodiments, it is clear that the present invention provides a method for preparing a device that can reversibly switch between multiple colors through electrical regulation. This method is applicable to the fields of display, decoration, anti-counterfeiting, batteries, or energy-saving building materials. By applying a small voltage externally, the device can achieve multi-color changes. The change process is reversible and has a certain memory retention characteristic, that is, it can still maintain the color when there is no external voltage or energy input. This satisfies people's needs for color and achieves high-quality energy-saving display. It has broad application prospects in the field of static display.

[0100] It should be understood that the above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A full-color reversible switchable electrically controlled color-changing device, characterized in that, Including the color-changing layer and the electrolyte; The color-changing layer includes a substrate, a conductive layer, and an active material layer. The active material layer forms physical interference with the conductive layer or the substrate to produce structural color. The electrolyte is in contact with the active material layer. When an electrochemical reaction occurs between the electrolyte and the surface of the active material layer, the thickness of the active material layer changes, causing a change in the interference parameters of the physical interference.

2. The electrically controlled color-changing device according to claim 1, characterized in that, It also includes a counter electrode that is electrically connected to the electrolyte.

3. The electrically controlled color-changing device according to claim 2, characterized in that, The counter electrode and the color-changing layer are stacked together along the thickness direction or arranged side by side along the width direction.

4. The electrically controlled color-changing device according to claim 2, characterized in that, The counter electrode is transparent or semi-transparent.

5. The electrically controlled color-changing device according to claim 1, characterized in that, The electrolyte contains a variety of cations.

6. The electrically controlled color-changing device according to claim 5, characterized in that, The cations in the electrolyte include H. + Li + Al 3+ Na + K + 、Rb + Ag + Ni 2+ Ca 2+ Mo 6+ Mn 2+ Ti 4+ V 4+ Zn 2+ W 6+ Ta 5+ Cu 2+ Bi 3+ Sn 4+ Mg 2+ Cs + Any two or more combinations of the above.

7. The electrically controlled color-changing device according to claim 6, characterized in that, The electrolyte contains a zinc salt compound.

8. The electrically controlled color-changing device according to claim 7, characterized in that, The zinc salt compound includes any one or a combination of two or more of Zn(ClO4)2, Zn(NO3)2, ZnSO4, ZnCl2 or Zn(Ac)2.

9. The electrically controlled color-changing device according to claim 7, characterized in that, The electrolyte can be in liquid, gel, or solid state.

10. The electrically controlled color-changing device according to claim 1, characterized in that, The active material layer is made of any one or a combination of two or more of the following: metal oxides, metals, and polymers.

11. The electrically controlled color-changing device according to claim 10, characterized in that, The active material layer is made of any one or more of the following materials: ZnO, MnO2, MoO3, WO3, Fe3O4, Fe2O3, NiO, VO2, V2O5, TiO2, CuO, Cu2O, Al2O3, Ta2O5, Ag2O, Ag, Cu, Al, Ni, Zn, Bi, Au, Pt, polyaniline, polythiophene, and polypyrrole. The material of the conductive layer includes any one or a combination of two of the following: metal and non-metal conductive materials. The conductive layer is made of any one or more of the following materials: Cu, Ag, W, Ti, V, Fe, Cr, Ni, Zn, Al, Mo, Au, Pd, Co, Ta, Pt, Mg, carbon materials, conductive metal oxides, and conductive polymer materials.

12. The electrically controlled color-changing device according to claim 1, characterized in that, The structure of the conductive layer can be any one of a one-dimensional thin film, a two-dimensional photonic crystal, a three-dimensional photonic crystal, or nanoparticles.

13. The electrically controlled color-changing device according to claim 1, characterized in that, The structure of the active material layer can be any one of a one-dimensional thin film, a two-dimensional photonic crystal, a three-dimensional photonic crystal, or nanoparticles.

14. A method for preparing an electrically regulated color-changing device according to any one of claims 1-13, characterized in that, include: A conductive layer is formed on the substrate; The electrolyte is brought into contact with the conductive layer, and an active material layer is formed between the electrolyte and the conductive layer by electrochemical deposition to form an electro-controlled color-changing device. Alternatively, an active material layer can be formed on the surface of the conductive layer, and then the electrolyte can be brought into contact with the active material layer to form an electrically regulated color-changing device; When the electrolyte reacts electrochemically with the surface of the active material layer, the thickness of the active material layer changes, causing a change in the interference parameters of the physical interference.

15. A color control method for an electrically regulated color-changing device according to any one of claims 1-13, characterized in that... include: Provide an electrically regulated color-changing device according to any one of claims 1-13; A voltage is applied between the conductive layer and the electrolyte, and by adjusting the application time of the applied voltage, the electro-controlled color-changing device can exhibit different colors.

16. The color control method according to claim 15, characterized in that, Also includes: A reverse voltage is applied between the conductive layer and the electrolyte to reversibly restore the color exhibited by the electro-controlled color-changing device. The applied voltage is below 6V, and the application time is 0-160s. By adjusting the application time, the electro-controlled color-changing device can exhibit any one of the following colors: red, orange, yellow, green, blue, indigo, and violet.

17. The application of the electro-controlled color-changing device according to any one of claims 1-13 in any of the fields of display, decoration, anti-counterfeiting, batteries, and energy-saving building materials.

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