Electrochromic device for camouflage and manufacturing method thereof

Abstract

An electrochromic device for camouflage and a method of manufacturing the same are provided. The electrochromic device for camouflage includes: a lower plate including a lower substrate and a lower color-changing layer provided on the lower substrate; an upper plate disposed on the lower plate and including an upper substrate, an upper color-changing layer disposed on the upper substrate, and an upper hole exposing a portion of the lower color-changing layer; the protection plate is arranged on the upper color changing layer; and an electrolyte disposed between the upper plate and the protective plate and disposed in the upper hole of the upper plate.

Description

[0001] This application claims the priority of Korean Patent Application No. 10-2023-0177001, filed on December 7, 2023, and Korean Patent Application No. 10-2024-0162290, filed on November 14, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to an electrochromic device and a method of manufacturing the same, and more particularly, to an electrochromic device for stealth camouflage that adjusts its emissivity to prevent detection by an external device and a method of manufacturing the same. Background Art

[0003] Generally, an electrochromic device may have the ability to control the transmittance of light in the visible wavelength range, near-infrared (NIR) wavelength range, and infrared (IR) wavelength range. Utilizing this function, electrochromic devices are manufactured and sold as smart windows, which are designed to block light or project light to block thermal infrared radiation or to enhance the view in a building. Electrochromic devices can be used to make windows opaque for privacy or to block thermal infrared radiation, thereby reducing the amount of intense sunlight entering a building during a hot summer. Additionally, electrochromic devices can be used to adjust and control the emissivity (e) of an object or a living body. Thermal imaging devices used at night identify specific objects or living bodies by measuring the thermal temperature, which varies according to the change in the emissivity of the object or living body. An electrochromic device capable of controlling emissivity can change the emissivity emitted from an object or a living body, so that the emissivity of the object or living body has a value similar to that of the surrounding environment. It can also hide or camouflage the emissivity of an object or a living body to avoid detection by an external thermal infrared device. Summary of the Invention

[0004] The present disclosure provides an electrochromic device for camouflage, which can easily control the emissivity in the thermal infrared wavelength range.

[0005] Embodiments of the inventive concept provide an electrochromic device for camouflage, the device including: a lower plate including a lower substrate and a lower electrochromic layer disposed on the lower substrate; an upper plate including an upper substrate disposed on the lower plate, an upper electrochromic layer disposed on the upper substrate, and an upper hole exposing a part of the lower electrochromic layer; a protection plate disposed on the upper electrochromic layer; and an electrolyte disposed between the upper plate and the protection plate and disposed in the upper hole of the upper plate.

[0006] In an embodiment, the lower plate may further include a lower electrode disposed between the lower substrate and the lower electrochromic layer.

[0007] In an embodiment, the lower color-changing layer and the lower electrode may be aligned with the upper hole.

[0008] In an embodiment, the upper plate may further include an upper electrode disposed between the upper substrate and the upper color-changing layer.

[0009] In an embodiment, the upper color-changing layer may have an upper color-changing tail disposed on a sidewall of the upper electrode within the upper hole.

[0010] In an embodiment, the electrochromic device for camouflage may further include an intermediate plate disposed between the lower plate and the upper plate.

[0011] In an embodiment, the intermediate plate may include an intermediate substrate, an intermediate color-changing layer disposed on the intermediate substrate, and an intermediate hole exposing a portion of the lower color-changing layer.

[0012] In an embodiment, the intermediate plate may further include an intermediate electrode disposed between the intermediate substrate and the intermediate color-changing layer.

[0013] In an embodiment, the intermediate color-changing layer may have an intermediate color-changing tail disposed on a sidewall of the intermediate electrode within the intermediate hole.

[0014] In an embodiment, the diameter of the intermediate hole may be smaller than the diameter of the upper hole.

[0015] In an embodiment of the inventive concept, an electrochromic device for camouflage includes: a lower plate including a lower substrate, a lower electrode disposed on the lower substrate, and a lower color-changing layer disposed on the lower electrode; an intermediate plate including an intermediate substrate disposed on the lower plate, an intermediate electrode disposed on the intermediate substrate, an intermediate color-changing layer disposed on the intermediate electrode, and an intermediate hole exposing a portion of the lower color-changing layer; an upper plate including an upper substrate disposed on the intermediate color-changing layer, an upper electrode disposed on the upper substrate, an upper color-changing layer disposed on the upper electrode, and an upper hole exposing a portion of the lower color-changing layer; a protection plate disposed on the upper color-changing layer; and an electrolyte disposed between the upper plate and the protection plate and disposed in the intermediate hole and the upper hole.

[0016] In an embodiment, the diameter of the intermediate hole may be smaller than the diameter of the upper hole.

[0017] In an embodiment, the upper color-changing layer may have an upper color-changing tail disposed on a sidewall of the upper electrode within the upper hole.

[0018] In an embodiment, the intermediate color-changing layer may have an intermediate color-changing tail disposed on a sidewall of the upper electrode in the intermediate hole.

[0019] In an embodiment, each of the intermediate electrode and the intermediate color-changing layer may have an annular shape.

[0020] In an embodiment of the inventive concept, a method of manufacturing an electrochromic device for camouflage includes: manufacturing a lower plate including a lower substrate, a lower electrode disposed on the lower substrate, and a lower color-changing layer disposed on the lower electrode; disposing an upper plate on the lower plate, wherein the upper plate includes an upper substrate, an upper electrode disposed on the upper substrate, an upper color-changing layer disposed on the upper electrode, and an upper hole exposing a part of the lower color-changing layer; disposing an electrolyte in the upper hole and on the upper color-changing layer; and disposing a protection plate on the electrolyte.

[0021] In an embodiment, the method may further include disposing an intermediate plate between the lower plate and the upper plate, the intermediate plate including an intermediate substrate, an intermediate electrode disposed on the intermediate substrate, and an intermediate color-changing layer disposed on the intermediate electrode.

[0022] In an embodiment, the intermediate plate may have an intermediate hole exposing a part of the lower color-changing layer.

[0023] In an embodiment, a diameter of the intermediate hole may be smaller than a diameter of the upper hole.

[0024] In an embodiment, the upper color-changing layer may include an upper color-changing tail disposed on a sidewall of the upper electrode in the upper hole, and the intermediate color-changing layer may include an intermediate color-changing tail disposed on a sidewall of the upper electrode in the intermediate hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are included to provide a further understanding of the inventive concept, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the inventive concept and, together with the specification, serve to explain the principles of the inventive concept. In the drawings: Figure 1 is a plan view showing an example of an electrochromic device for camouflage according to an embodiment of the inventive concept; Figures 2A to 2D is a cross-sectional view taken along line I-I' of Figure 1 and its variations; Figure 3 is a plan view showing another example of an electrochromic device for camouflage according to an embodiment of the inventive concept; Figures 4A to 4Dis taken along Figure 3 sectional view II-II' and its variations taken along the line; Figure 5A and Figure 5B is a sectional view showing another example of an electrochromic device for camouflage according to an embodiment of the inventive concept; Figure 6A and Figure 6B is a sectional view showing another example of an electrochromic device for camouflage according to an embodiment of the inventive concept; Figures 7A to 7E is a process sectional view of an electrochromic device for camouflage according to an embodiment of the inventive concept; Figure 8 is a picture showing another example of an electrochromic device for camouflage according to an embodiment of the inventive concept; Figure 9 shows Figure 8 a spectrogram of an example of the preparation state, decolorized state, and colored state of an electrochromic device for camouflage; Figure 10 is a plan view showing another example of an electrochromic device for camouflage according to an embodiment of the inventive concept; and Figures 11A to 11D is taken along Figure 10 sectional view III-III' and its variations taken along the line. DETAILED DESCRIPTION

[0026] Hereinafter, preferred embodiments of the inventive concept will be described in detail with reference to the accompanying drawings. Through the following embodiments described with reference to the accompanying drawings, the advantages and features of the inventive concept and methods for implementing them will be clarified. However, the inventive concept may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Instead, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the inventive concept to those skilled in the art, which is defined only by the scope of the claims. Like reference numerals always denote like elements.

[0027] The terms used in this specification are only for explaining the embodiments and do not limit the disclosure. In this specification, unless the context clearly indicates otherwise, the singular forms also include the plural forms. Expressions including components, operations, and / or elements do not exclude other components, operations, and / or elements. Since preferred embodiments are provided below, the order of the reference numerals given in the description is not limited thereto.

[0028] In addition, the embodiments described in this specification will be explained with reference to cross-sectional views and / or plan views that are ideal exemplary views of the present disclosure. In the drawings, the thicknesses of the films and regions are exaggerated for effective description of the technical content. Therefore, the shapes of the exemplary views can be modified according to manufacturing techniques and / or allowable errors. Accordingly, the embodiments of the present inventive concept are not limited to the specific shapes shown in the exemplary views, but may include other shapes generated according to manufacturing processes.

[0029] Figure 1 An example of an electrochromic device 100 for camouflage (hereinafter, referred to as the camouflage electrochromic device 100) according to an embodiment of the present inventive concept is shown. Figures 2A to 2D A cross-sectional view taken along Figure 1 line I-I' and its variations are shown.

[0030] Referring to Figure 1 and Figures 2A to 2D , the camouflage electrochromic device 100 of the present inventive concept may include a lower plate 10, an upper plate 30, an electrolyte 40, and a protection plate 50.

[0031] The lower plate 10 may be disposed below the upper plate 30 and the electrolyte 40. According to one example, the lower plate 10 may include a lower substrate 12, a lower electrode 14, and a lower electrochromic layer 16.

[0032] The lower substrate 12 may be disposed below the lower electrode 14. For example, the lower substrate 12 may include a material such as glass or plastic. Optionally, the lower substrate 12 may include an opaque polymer plate or a metal plate. For example, the lower substrate 12 may include PET (polyethylene terephthalate), PE (polyethylene), or FEP (fluorinated ethylene propylene), but the present inventive concept is not limited thereto. The lower substrate 12 may have a thickness of about 125 μm. The lower substrate 12 may have various thicknesses, but the embodiments of the present inventive concept are not limited thereto.

[0033] The lower electrode 14 may be disposed on the lower substrate 12. The lower electrode 14 may be disposed on the entire surface of the lower substrate 12, or may be discretely separated. For example, the lower electrode 14 may include a transparent metal oxide such as ITO (indium tin oxide) or FTO (fluorine-doped tin oxide). Optionally, the lower electrode 14 may include indium zinc oxide (IZO), indium tin oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), tungsten-doped zinc oxide (WZO), tungsten-doped tin oxide (WTO), gallium-doped zinc oxide (GZO), antimony-doped tin oxide (ATO), indium-doped indium zinc oxide (IZO), niobium (Nb)-doped titanium oxide (TiO x), at least one of single or multiple oxide-metal-oxide (OMO), conductive polymer, conductive organic molecule, carbon nanotube, graphene, silver nanowire, aluminum, silver, ruthenium, gold, platinum, tin, chromium, indium, zinc, copper, rubidium, nickel, ruthenium oxide, rubidium oxide, tin oxide, indium oxide, zinc oxide, chromium oxide, and molybdenum, but the inventive concept is not limited thereto. The lower electrode 14 may have a sheet resistance of about 30 Ω.

[0034] The lower color-changing layer 16 may be disposed on the lower electrode 14. The lower color-changing layer 16 may change color in response to a bias voltage between the lower electrode 14 and the upper plate 30. The lower color-changing layer 16 may include iridium oxide (IrO 2 and IrO 5 ). Optionally, the lower color-changing layer 16 may include Prussian blue, viologen, phenothiazine, or a conductive polymer, but the inventive concept is not limited thereto. The lower color-changing layer 16 may have a thickness of about 600 nm. The lower color-changing layer 16 may have various thicknesses, but the inventive concept is not limited thereto.

[0035] The upper plate 30 may be disposed on the lower plate 10. The upper plate 30 may have an upper hole 38. The upper hole 38 may be disposed at the center of the upper plate 30. The upper hole 38 may expose a part of the center of the lower color-changing layer 16. In a plan view, the surface area of the upper hole 38 may be about 20% to about 30% of the surface area of the upper plate 30. The ratio of the surface area of the upper hole 38 to the surface area of the upper plate 30 may vary, but the inventive concept is not limited thereto. According to an example, the upper plate 30 may include an upper substrate 32, an upper electrode 34, and an upper color-changing layer 36.

[0036] The upper substrate 32 may be disposed below the upper electrode 34. The upper substrate 32 may include a transparent substrate. The upper substrate 32 may include a material such as glass, plastic, or polymer. For example, the upper substrate 32 may include PET (polyethylene terephthalate), PE (polyethylene), or FEP (fluorinated ethylene propylene), but the inventive concept is not limited thereto. The upper substrate 32 may have a thickness of about 125 nm. The upper substrate 32 may have various thicknesses, but the inventive concept is not limited thereto.

[0037] The upper electrode 34 may be disposed on the upper substrate 32. The upper electrode 34 may include a transparent electrode. The upper electrode 34 may include the same material as the lower electrode 14. For example, the upper electrode 34 may include ITO or FTO. Optionally, the upper electrode 34 may include indium zinc oxide (IZO), indium tin oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), tungsten-doped zinc oxide (WZO), tungsten-doped tin oxide (WTO), gallium-doped zinc oxide (GZO), antimony-doped tin oxide (ATO), indium-doped indium zinc oxide (IZO), niobium (Nb)-doped titanium oxide (TiO x ), single or multiple oxide-metal-oxide (OMO), conductive polymer, conductive organic molecule, carbon nanotube, graphene, silver nanowire, aluminum, silver, ruthenium, gold, platinum, tin, chromium, indium, zinc, copper, rubidium, nickel, ruthenium oxide, rubidium oxide, tin oxide, indium oxide, zinc oxide, chromium oxide, and molybdenum, but the inventive concept is not limited thereto. The upper electrode 34 may have a sheet resistance of about 30 Ω. The lower electrode 14 is grounded, and a bias voltage may be applied to the upper electrode 34. The lower color-changing layer 16 and the upper color-changing layer 36 may change colors, that is, color or decolorize.

[0038] The upper color-changing layer 36 may be disposed on the upper electrode 34. The upper color-changing layer 36 may adjust the emissivity in the thermal infrared wavelength range (e.g., 0.8 μm to 30 μm). For example, the upper color-changing layer 36 may include tungsten oxide (WO 3 ). Tungsten oxide (WO 3 ). Tungsten oxide (WO 3 ) may have the characteristic of variable transmittance from visible light wavelength to infrared wavelength. Tungsten oxide (WO

[0039] ) has the characteristic of variable emissivity of the thermal infrared light 39. The surface area of the upper color-changing layer 36 may be larger than the surface area of the portion of the lower color-changing layer 16 exposed through the upper hole 38. That is, in a cross-sectional view, the upper color-changing layer 36 may be wider than the portion of the lower color-changing layer 16 exposed through the upper hole 38. When the aperture ratio of the upper color-changing layer 36 is about 60% to 80%, the aperture ratio of the lower color-changing layer 16 exposed through the upper hole 38 may be about 20% to about 40%, where the aperture ratio of the upper color-changing layer 36 refers to the ratio of the planar area of the upper color-changing layer 36 to the planar area of the protection plate 50, and the aperture ratio of the lower color-changing layer 16 refers to the ratio of the planar area of the lower color-changing layer 16 located in the upper hole 38 (i.e., the planar area of the portion of the lower color-changing layer 16 exposed through the upper hole 38) to the planar area of the protection plate 50. The upper color-changing layer 36 may have a thickness of about 600 nm. The upper color-changing layer 36 may have various thicknesses, but the inventive concept is not limited thereto.The electrolyte 40 can be disposed on the lower plate 10 and the upper plate 30. The electrolyte 40 can be disposed in the upper holes 38. The electrolyte 40 can move through the upper holes 38. The electrolyte 40 can color or decolor the lower color-changing layer 16 and the upper color-changing layer 36 through the ion reaction of the lower color-changing layer 16 and the upper color-changing layer 36. The electrolyte 40 can include an ion-gel electrolyte or a polymer electrolyte. The electrolyte 40 can have the physical properties of a liquid, a gel, or a solid. The electrolyte 40 can also include polymers such as PVB, PMMA, or PVA to adjust its viscosity and viscoelasticity. The electrolyte 40 can include various organic molecules or inorganic molecules containing ionic liquids, LiClO 4 , HCl, and other molecules containing Li + ions and H + ions. The electrolyte 40 can have a thickness in the range of 10 nm to several hundred micrometers (μm). The electrolyte 40 can include polymers, organic molecules, ionic liquids, solvents, or ionic molecules. The electrolyte 40 composed of polymers can include PEG (polyethylene glycol), PMMA (polymethyl methacrylate), PBA (polybutyl acrylate), PVB (polyvinyl butyrate), PVA (polyvinyl alcohol), PEO (polyethylene oxide), PPO (polypropylene oxide), PAN (polyacrylonitrile), PVDF (polyvinylidene fluoride), and can include at least one of PVDF-HFP (polyvinylidene fluoride-hexafluoropropylene copolymer) and block copolymers. The electrolyte 40 composed of organic molecules, solvents, and ionic liquids can include propylene carbonate (PC), butylene carbonate (BC), ethylene carbonate (EC), gamma-butyrolactone (γ-BL), gamma-VL, NMO, dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), propyl methyl carbonate (PMC), ethyl acetate (EA), ethylene blue (EB), water (H 2 O), acetone, ethanol, methylene blue (MB), morpholinium cation, imidazolium cation, quaternary ammonium cation, quaternary phosphonium cation, and at least one of Br-, Cl-, NO 3 -, BF 4 -, PF 6 -, CH 3 CO 2 -, TFSI, CF3SO 3 -, N(SO 2 CF 3 )2-, and CF 3 WO 2 -. The ionic molecules can include at least one of lithium ion products and hydrogen ion products. The electrolyte 40 composed of lithium ion products can include lithium perchlorate (LiClO 4 ), LiBF 4, LiPF 6 , LiAsF 6 , LiTf (lithium trifluoromethanesulfonate, LiCF 3 SO 3 ), LiIm (lithium Imdide, Li[N(SO 2 CF 3 ) 2 ), LiBeTi (Li[N(SO 2 CF 2 CF 3 ) 2 ), LiBr, LiIy, and at least one of other electrolytes including lithium (Li), electrolytes including Na, and electrolytes including K. The electrolyte 40 composed of hydrogen ion products may include at least one of hydrochloric acid (HCl), sulfuric acid (H 2 SO 4 ), nitric acid (HNO 3 ), phosphoric acid (H 3 PO 4 ), acetic acid (CH 3 COOH), perchloric acid (HClO 4 ), and formic acid (HCOOH). Although not shown, the electrolyte 40 may include a lower electrolyte layer between the lower plate 10 and the upper plate 30, an intermediate electrolyte layer disposed in the upper holes 38 of the upper plate 30, and an upper electrolyte layer between the upper plate 30 and the protection plate 50. The lower electrolyte layer, the intermediate electrolyte layer, and the upper electrolyte layer may move relative to each other to eliminate their ion concentration differences. The thickness of each of the lower electrolyte layer, the intermediate electrolyte layer, and the upper electrolyte layer may be inversely proportional to the emissivity of the thermal infrared light. Each of the lower electrolyte layer, the intermediate electrolyte layer, and the upper electrolyte layer may have a thickness of several tens of nm to several hundreds of μm.

[0040] The protection plate 50 may be disposed on the electrolyte 40. The protection plate 50 may include PET (polyethylene terephthalate), PE (polyethylene), or FEP (fluorinated ethylene propylene), but the inventive concept is not limited thereto.

[0041] Referring to Figure 2A and Figure 2B , the lower electrode 14 and the lower color-changing layer 16 may be disposed on the entire surface of the lower substrate 12. The electrolyte 40 may be disposed between the lower color-changing layer 16 and the upper substrate 32, and also between the upper color-changing layer 36 and the protection plate 50. The electrolyte 40 may be disposed in the upper holes 38. The upper color-changing layer 36 may control the emissivity of the thermal infrared radiation. The thermal infrared light 39 may be reflected by the upper electrode 34. The upper color-changing layer 36 may change the transmittance or absorptivity (or emissivity) of the thermal infrared light 39 according to the coloring and color-changing of the device.

[0042] Referring to Figure 2B and Figure 2D , the upper color-changing layer 36 may have an upper color-changing tail 37. The upper color-changing tail 37 may be disposed on a sidewall of the upper color-changing layer 36 that is located in the upper hole 38. The upper color-changing tail 37 may increase the aperture ratio of the upper color-changing layer 36.

[0043] Referring to Figure 2C and Figure 2D , the lower electrode 14 and the lower color-changing layer 16 may be discretely separated and thus disposed in the upper hole 38. The bottom surface of the upper substrate 32 may be in contact with the top surface of the lower substrate 12. The lower color-changing layer 16 may be narrower than the upper color-changing layer 36.

[0044] Accordingly, the camouflage electrochromic device 100 of the inventive concept may be easily adjusted for the emissivity of the thermal infrared light 39 by using the upper color-changing layer 36 including tungsten oxide (WO 3 ), and having a surface area such that the surface area of the upper color-changing layer 36 is larger than the surface area of the portion of the lower color-changing layer 16 that is exposed through the upper hole 38.

[0045] Figure 3 FIG. shows another example of the camouflage electrochromic device 100 according to an embodiment of the inventive concept. Figures 4A to 4D is a cross-sectional view taken along line II-II' of Figure 3 and its variations.

[0046] Referring to Figure 3 as well as Figures 4A to 4D , in the cross-sectional view, compared to the upper hole in Figure 1 as well as Figures 2A to 2D , the upper hole 38 of the camouflage electrochromic device 100 of this example may expose the lower color-changing layer 16 wider. The lower color-changing layer 16 may include tungsten oxide (WO 3 ), thereby being able to adjust the emissivity of the thermal infrared light 39. The upper hole 38 may expose the lower color-changing layer 16 with an aperture ratio of about 60% to about 80%. As described above, the aperture ratio of the lower color-changing layer 16 refers to the ratio of the planar area of the lower color-changing layer 16 that is located in the upper hole 38 to the planar area of the protection plate 50. The aperture ratio of the upper color-changing layer 36 may be about 20% to 40%. As described above, the aperture ratio of the upper color-changing layer 36 refers to the ratio of the planar area of the upper color-changing layer 36 to the planar area of the protection plate 50. The surface area or aperture ratio of the upper color-changing layer 36 may be different from the surface area or aperture ratio of the upper hole 38, where the aperture ratio of the upper hole 38 refers to the ratio of the planar area of the upper hole 38 to the planar area of the protection plate 50, but the inventive concept is not limited thereto. The upper color-changing layer 36 may include iridium oxide (IrO 2 and IrO 5), or nickel oxide (NiO). Optionally, the upper color-changing layer 36 may include Prussian blue, viologen, phenothiazine, or a conductive polymer, but the inventive concept is not limited thereto.

[0047] Referring to Figure 4A and Figure 4B , the lower electrode 14 and the lower color-changing layer 16 may be disposed on the entire surface of the lower substrate 12. The electrolyte 40 may be disposed between the lower color-changing layer 16 and the upper substrate 32, and may also be disposed between the upper color-changing layer 36 and the protection plate 50. Additionally, the electrolyte 40 may be disposed within the upper hole 38. The lower color-changing layer 16 exposed through the upper hole 38 may control the emissivity of the thermal infrared light. The thermal infrared light 39 may be reflected by the lower electrode 14. The lower color-changing layer 16 may change the transmittance or absorptivity (or emissivity) of the thermal infrared light 39 according to the coloring and decoloring changes of the device.

[0048] Referring to Figure 4B and Figure 4D , the upper color-changing layer 36 may have an upper color-changing tail 37. The upper color-changing tail 37 may be disposed on the sidewall of the upper electrode 34 located within the upper hole 38.

[0049] Referring to Figure 4C and Figure 4D , the lower electrode 14 and the lower color-changing layer 16 may be discretely separated and thus aligned with the upper hole 38. The bottom surface of the upper substrate 32 may contact the top surface of the lower substrate 12.

[0050] Therefore, the camouflage electrochromic device 100 according to the inventive concept may easily adjust the emissivity of the thermal infrared light 39 by using a lower color-changing layer 16 including tungsten oxide (WO 3 ) and having a portion thereof exposed as follows: the portion of the lower color-changing layer 16 exposed through the upper hole 38 is wider than the upper color-changing layer 36.

[0051] The compositions of the lower substrate 12, the lower electrode 14, the upper substrate 32, the upper electrode 34, the upper color-changing layer 36, the electrolyte 40, and the protection plate 50 may be the same as those in Figure 1 and Figures 2A to 2D .

[0052] Figure 5A and Figure 5B show another example of the camouflage electrochromic device 100 according to an embodiment of the inventive concept.

[0053] Referring to Figure 5A and Figure 5B, the lower color-changing layer 16 and the upper substrate 32 are spaced apart from each other, and the electrolyte 40 can be disposed between the lower color-changing layer 16 and the upper substrate 32. For example, the lower color-changing layer 16 and the lower electrode 14 can be disposed on the entire surface of the lower substrate 12, or can be discretely separated and aligned with the upper holes 38. In a cross-sectional view, the width of the portion of the lower color-changing layer 16 exposed through the upper holes 38 is narrower than the width of the upper color-changing layer 36. The upper color-changing layer 36 can include tungsten oxide (WO 3 ) and has an aperture ratio of about 60% to about 80%. The lower color-changing layer 16 has an aperture ratio of about 20% to about 40% (as shown in Figure 5B ) and can be exposed through the upper holes 38.

[0054] The compositions of the lower substrate 12, the lower electrode 14, the lower color-changing layer 16, the upper substrate 32, the upper electrode 34, the upper color-changing layer 36, the electrolyte 40, and the protective plate 50 can be the same as those in Figures 2A to 2D .

[0055] Figure 6A And Figure 6B show another example of the camouflage electrochromic device 100 according to an embodiment of the inventive concept.

[0056] Referring to Figure 6A And Figure 6B , compared with the upper holes 38 in Figure 5A And Figure 5B , the upper holes 38 in Figure 6A And Figure 6B can expose the lower color-changing layer 16 wider or denser, and the lower color-changing layer 16 can include tungsten oxide (WO 3 ). The lower color-changing layer 16 can increase and / or control the emissivity in the wavelength range of thermal infrared. As shown in Figure 6B , the aperture ratio of the lower color-changing layer 16 can be about 60% to about 80%. The lower color-changing layer 16 and the lower electrode 14 can be disposed on the entire surface of the lower substrate 12 (as shown in Figure 6A ), or can be discretely separated and aligned with the upper holes 38 (as shown in Figure 6B ).

[0057] The compositions of the lower substrate 12, the lower electrode 14, the lower color-changing layer 16, the upper substrate 32, the upper electrode 34, the upper color-changing layer 36, the electrolyte 40, and the protective plate 50 can be the same as those in Figures 4A to 4D .

[0058] A method for manufacturing the camouflage electrochromic device 100 of the inventive concept having the above-described configuration is as follows.

[0059] Figures 7A to 7EIt is a process cross-sectional view of a camouflage electrochromic device according to an embodiment of the inventive concept.

[0060] Referring to Figure 7A , a lower electrode 14 and a lower color-changing layer 16 can be formed on the lower substrate 12, thereby forming the lower plate 10. The lower electrode 14 may include ITO or FTO formed by sputtering. The lower color-changing layer 16 may include tungsten oxide (WO 3 ). Optionally, the lower color-changing layer 16 may include iridium oxide (IrO 2 and IrO 5 ) or nickel oxide (NiO).

[0061] Referring to Figure 7B , a part of each of the lower electrode 14 and the lower color-changing layer 16 can be removed. The lower electrode 14 and the lower color-changing layer 16 can be patterned by a lithography process, an etching process, and / or a laser process. The lithography process may include a photolithography process or an ion beam printing process. The etching process may include a dry etching process, a wet etching process, or a laser etching process.

[0062] Referring to Figure 7C , an electrolyte 40 can be formed on the lower plate 10 such that a part of the electrolyte 40 is formed in the removed parts of the lower electrode 14 and the lower color-changing layer 16 of the lower plate 10. The electrolyte 40 may include an ion gel electrolyte or a polymer electrolyte and is formed by a dropping method, a printing method, a transfer method, a slot-die coating method, or a wet coating method.

[0063] Referring to Figure 7D , an upper plate 30 can be provided. The upper plate 30 can be provided on the electrolyte 40. According to an example, the upper plate 30 may include an upper substrate 32, an upper electrode 34, and an upper color-changing layer 36. The upper substrate 32 may include a material such as glass or plastic. The upper electrode 34 may include ITO or FTO formed by sputtering. When the lower color-changing layer 16 includes tungsten oxide (WO 3 ), the upper color-changing layer 36 may include iridium oxide (IrO 2 and IrO 5 ) or nickel oxide (NiO). When the lower color-changing layer 16 includes iridium oxide (IrO 2 and IrO 5 ) or nickel oxide (NiO), the upper color-changing layer 36 may include tungsten oxide (WO 3). The upper substrate 32, the upper electrode 34, and the upper electrochromic layer 36 may have upper holes 38. The upper holes 38 may be formed in the upper substrate 32, the upper electrode 34, and the upper electrochromic layer 36 by an etching process, an engraving process, or a laser process. The upper holes 38 may expose a portion of the electrolyte 40 located on the lower electrochromic layer 16.

[0064] Referring to Figure 7E , the electrolyte 40 may be additionally formed on the upper plate 30 and within the upper holes 38. The electrolyte 40 may be formed by a drop-casting method, a printing method, a transfer method, a slot-die coating method, or a wet coating method.

[0065] In addition, a protection plate 50 may be disposed on the electrolyte 40. The protection plate 50 may include a transparent polyethylene film.

[0066] Figure 8 is a picture showing another example of the camouflage electrochromic device 100 according to an embodiment of the inventive concept.

[0067] Referring to Figure 5A and Figure 8 , the camouflage electrochromic device 100 of the inventive concept may be arranged in a plurality of arrays. The lower electrode 14 is grounded, and the upper electrode 34 may be connected to a pad 101 to receive a bias voltage.

[0068] Figure 9 is a diagram showing Figure 8 an example of the standby state 11, the bleaching state 13, and the coloring state 15 of the camouflage electrochromic device 100 in

[0069] Referring to Figure 5A , Figure 8 and Figure 9 , the camouflage electrochromic device 100 may change its color by a bias voltage between the lower electrode 14 and the upper electrode 34. When no bias voltage is applied between the lower electrode 14 and the upper electrode 34, the camouflage electrochromic device 100 may be in the standby state 11. The camouflage electrochromic device 100 in the standby state 11 may be almost transparent.

[0070] When a bias voltage of about 2V is applied between the lower electrode 14 and the upper electrode 34, the camouflage electrochromic device 100 may be in the bleaching state 13. In the visible wavelength range and the thermal infrared wavelength range, the camouflage electrochromic device 100 in the bleaching state 13 may have a transmittance lower than that in the standby state 11.

[0071] When a bias voltage of about -1.7 V is applied between the lower electrode 14 and the upper electrode 34, the camouflage electrochromic device 100 can be in the colored state 15. The colored state 15 can have a lower transmittance than the bleached state 13. For example, in the near-infrared wavelength range of about 1500 nm, the camouflage electrochromic device 100 in the colored state 15 can have a transmittance of about 4.8%. The camouflage electrochromic device 100 in the bleached state 13 can have a transmittance of about 24.1%.

[0072] Figure 10 Another example of the camouflage electrochromic device 100 according to an embodiment of the inventive concept is shown. Figures 11A to 11C is a cross-sectional view taken along line III-III' of Figure 10 and its variants.

[0073] Referring to Figure 10 and Figures 11A to 11C , the camouflage electrochromic device 100 of the inventive concept may further include an intermediate plate 20.

[0074] The intermediate plate 20 may be disposed between the lower plate 10 and the upper plate 30. For example, the intermediate plate 20 may have an intermediate hole 28. In addition, the diameter of the intermediate hole 28 may be smaller than the diameter of the upper hole 38. In a plan view, the region of the intermediate plate 20 located between the intermediate hole 28 and the upper hole 38 may have an annular shape or a donut shape. According to one example, the intermediate plate 20 may include an intermediate substrate 22, an intermediate electrode 24, and an intermediate electrochromic layer 26.

[0075] The intermediate substrate 22 may be disposed below the intermediate electrode 24 and the intermediate electrochromic layer 26. The intermediate substrate 22 may include a transparent substrate made of glass or plastic. For example, the intermediate substrate 22 may include PET (polyethylene terephthalate), PE (polyethylene), or FEP (fluorinated ethylene propylene), but the inventive concept is not limited thereto.

[0076] The intermediate electrode 24 may be disposed on the intermediate substrate 22. The intermediate electrode 24 may include ITO or FTO.

[0077] The intermediate electrochromic layer 26 may be disposed on the intermediate electrode 24. The intermediate electrochromic layer 26 may contain iridium oxide (IrO 2 and IrO 5 ) or nickel oxide (NiO). Additionally, the intermediate electrochromic layer 26 may include prussian blue or phenothiazine, but the inventive concept is not limited thereto.

[0078] The intermediate electrochromic layer 26 may include a material different from that of at least one of the lower electrochromic layer 16 and the upper electrochromic layer 36. When the upper electrochromic layer 36 includes iridium oxide (IrO 2 and IrO 5), the intermediate electrochromic layer 26 may include nickel oxide (NiO). When the upper electrochromic layer 36 includes nickel oxide (NiO), the intermediate electrochromic layer 26 may include iridium oxide (IrO 2 and IrO 5 ). Optionally, the intermediate electrochromic layer 26 and the upper electrochromic layer 36 may also include Prussian blue, viologen, or a conductive polymer, but the inventive concept is not limited thereto.

[0079] The lower electrochromic layer 16 may include tungsten oxide (WO 3 ). The lower electrochromic layer 16 may have an aperture ratio of about 60% to about 80%, the intermediate electrochromic layer 26 may have an aperture ratio of about 10% to about 20% (i.e., the ratio of the planar area of the intermediate electrochromic layer 26 located in the upper hole 38 to the planar area of the protection plate 50), and the upper electrochromic layer 36 may have an aperture ratio of about 10% to about 20%.

[0080] Referring to Figure 11A , the intermediate plate 20 may be wider than the upper plate 30 and narrower than the lower plate 10.

[0081] Referring to Figure 11B , the outer diameter of the intermediate plate 20 may be the same as the inner diameter of the upper hole 38, so that the intermediate plate 20 may have an overall annular shape.

[0082] Referring to Figure 11C , the intermediate electrode 24 and the intermediate electrochromic layer 26 of the intermediate plate 20 may be separately patterned on the intermediate substrate 22, such that the intermediate electrode 24 and the intermediate electrochromic layer 26 may be narrower than the intermediate substrate 22 and may have an annular shape.

[0083] Referring to Figure 11D , the intermediate electrochromic layer 26 may have an intermediate electrochromic tail 27. The intermediate electrochromic tail 27 may be disposed on the sidewall of the intermediate electrode 24 located in the intermediate hole 28. The intermediate electrochromic tail 27 may increase the effective electrochromic efficiency of the intermediate electrochromic layer 26.

[0084] The compositions of the lower substrate 12, the lower electrode 14, the lower electrochromic layer 16, the upper substrate 32, the upper electrode 34, the upper electrochromic layer 36, the electrolyte 40, and the protection plate 50 may be the same as those in Figures 2A to 2D and Figures 4A to 4D .

[0085] The electrochromic device for camouflage according to an embodiment of the inventive concept may easily control the emissivity in the thermal infrared wavelength range by using the lower electrochromic layer and the upper electrochromic layer including tungsten oxide (WO 3 ).

[0086] Embodiments have been described in the drawings and the specification. Although specific terms are used, they are not used to limit the meaning or scope of the inventive concept described in the claims, but are only used to explain embodiments of the inventive concept. Accordingly, those skilled in the art will understand that various modifications and other equivalent embodiments are also feasible. Therefore, the actual scope of protection of the present disclosure should be determined by the technical scope of the appended claims.

Claims

1. An electrochromic device for camouflage, the electrochromic device comprising: A lower plate, comprising a lower substrate and a lower color-changing layer disposed on the lower substrate; an upper plate comprising an upper substrate disposed on the lower plate, an upper color-changing layer disposed on the upper substrate, and an upper hole exposing a portion of the lower color-changing layer; A protection plate, disposed on the upper color-changing layer; as well as An electrolyte is disposed between the upper plate and the protection plate and is disposed in the upper hole of the upper plate.

2. The electrochromic device according to claim 1, wherein: The lower plate further includes a lower electrode disposed between the lower substrate and the lower color-changing layer.

3. The electrochromic device according to claim 2, wherein: The lower color-changing layer and the lower electrode are aligned with the upper hole.

4. The electrochromic device according to claim 1, wherein: The upper plate further includes an upper electrode disposed between the upper substrate and the upper color-changing layer.

5. The electrochromic device according to claim 4, wherein: The upper color-changing layer has an upper color-changing tail portion disposed on a side wall of the upper electrode located in the upper hole.

6. The electrochromic device of claim 1, further comprising an intermediate plate disposed between the lower plate and the upper plate.

7. The electrochromic device according to claim 6, wherein: The intermediate plate includes an intermediate substrate, an intermediate color-changing layer disposed on the intermediate substrate, and an intermediate hole exposing a portion of the lower color-changing layer.

8. The electrochromic device according to claim 7, wherein: The intermediate plate further includes an intermediate electrode disposed between the intermediate substrate and the intermediate color-changing layer.

9. The electrochromic device according to claim 8, wherein: The intermediate color-changing layer has an intermediate color-changing tail portion disposed on a side wall of the intermediate electrode located in the intermediate hole.

10. The electrochromic device according to claim 7, wherein: The diameter of the middle hole is smaller than the diameter of the upper hole.

11. An electrochromic device for camouflage, the electrochromic device comprising: A lower plate, comprising a lower substrate, a lower electrode disposed on the lower substrate, and a lower color-changing layer disposed on the lower electrode; an intermediate plate, comprising an intermediate substrate disposed on the lower plate, an intermediate electrode disposed on the intermediate substrate, an intermediate color-changing layer disposed on the intermediate electrode, and an intermediate hole exposing a portion of the lower color-changing layer; an upper plate, comprising an upper substrate disposed on the intermediate color-changing layer, an upper electrode disposed on the upper substrate, an upper color-changing layer disposed on the upper electrode, and an upper hole exposing a portion of the lower color-changing layer; A protection plate, disposed on the upper color-changing layer; as well as An electrolyte is disposed between the upper plate and the protection plate and is disposed in the middle hole and the upper hole.

12. The electrochromic device according to claim 11, wherein: The diameter of the middle hole is smaller than the diameter of the upper hole.

13. The electrochromic device according to claim 11, wherein: The upper color-changing layer has an upper color-changing tail portion disposed on a side wall of the upper electrode located in the upper hole.

14. The electrochromic device according to claim 11, wherein: The intermediate color-changing layer has an intermediate color-changing tail portion disposed on a side wall of the upper electrode located in the intermediate hole.

15. The electrochromic device according to claim 11, wherein: Each of the intermediate electrode and the intermediate color-changing layer has a ring shape.

16. A method for making an electrochromic device for camouflage, the method comprising: Manufacturing a lower plate, the lower plate comprising a lower substrate, a lower electrode disposed on the lower substrate, and a lower color-changing layer disposed on the lower electrode; An upper plate is disposed on the lower plate, wherein the upper plate includes an upper substrate, an upper electrode disposed on the upper substrate, an upper color-changing layer disposed on the upper electrode, and an upper hole exposing a portion of the lower color-changing layer; disposing an electrolyte in the upper hole and on the upper color-changing layer; and A protective plate is disposed on the electrolyte.

17. The method of claim 16, further comprising disposing an intermediate plate between the lower plate and the upper plate, the intermediate plate comprising an intermediate substrate, an intermediate electrode disposed on the intermediate substrate, and an intermediate color-changing layer disposed on the intermediate electrode.

18. The method of claim 17, wherein: The middle plate has a middle hole exposing a portion of the lower color-changing layer.

19. The method of claim 18, wherein: The diameter of the middle hole is smaller than the diameter of the upper hole.

20. The method of claim 18, wherein: The upper color-changing layer includes an upper color-changing tail portion disposed on a side wall of the upper electrode located in the upper hole, and the intermediate color-changing layer includes an intermediate color-changing tail portion disposed on a side wall of the upper electrode located in the intermediate hole.

Images