A multicolor electrochromic device and its fabrication method

Abstract

This invention belongs to the field of electrochromic technology, specifically relating to a multi-color electrochromic device and its fabrication method. Introducing an electrochromic composite thin film into traditional electrochromic devices can achieve large-area, patterned display effects. The electrochromic composite thin film prepared in this invention uses screen printing to print electrochromic materials onto a photonic crystal composite substrate. The color of different photonic crystals can be controlled by adjusting their size. Introducing a composite photonic crystal electrochromic layer effectively solves the problem of single-color limitations in traditional electrochromic devices. Compared to traditional patterned electrochromic devices, this invention uses a transfer printing method to fabricate electrochromic devices on different substrates. This fabrication method is convenient, fast, simple, and low-cost, providing a framework for the industrial production of large-area patterned multi-color electrochromic devices.

Description

Technical Field

[0001] This invention belongs to the field of electrochromic devices, specifically relating to a multicolor electrochromic device and its preparation method. Background Technology

[0002] With the development of the times, displays are becoming increasingly common in daily life and entertainment. Some aesthetically pleasing and fashionable electronic products and some beautiful decorative patterns are favored by people. Although the currently widely used light-emitting diodes (LEDs) or liquid crystal displays (LCDs) can bring high-quality color images and fast switching, the cost is high energy consumption. Especially when used outdoors in strong ambient light, reflected light increases significantly, which not only affects the viewing effect but also greatly increases energy consumption.

[0003] Electrochromic devices (ECDs) can achieve stable and reversible changes in transmittance, reflectance, and color by applying specific voltage switches. The most intuitive change is the color change in the visible light region achieved by adjusting the voltage. EC displays are widely used due to their advantages such as low cost, low driving voltage, power saving, simple structure, functional flexibility, and ideal visual friendliness.

[0004] Electrochromic materials are the core of ECD color change; however, most existing ECDs made from electrochromic materials suffer from low luminous efficiency and limited color variation, especially inorganic electrochromic materials, which suffer from a single color. Organic electrochromic materials also exhibit one-dimensional color change in the CIE coordinate system, generally only achieving a change from transparent to a single color, or requiring the design of complex double-layer EC devices for color mixing. This significantly limits the application of ECDs in multicolor displays.

[0005] Patent CN102608819A discloses a multicolor electrochromic device utilizing reversible metal electrodeposition, capable of switching between gray, black, copper, and silver, but large-area fabrication is not feasible. Patent CN114563896A discloses a multicolor inorganic all-solid-state electrochromic device, selecting V2O5, Co3O4, and Rh2O3 as materials for the multicolor ion storage layer. The device fabrication process is complex, and it only exhibits one-dimensional color changes in CIE coordinates.

[0006] Therefore, developing multicolor electrochromic devices with simple fabrication processes and multicolor tone modulation characteristics is an urgent problem to be solved for their application in the field of color rendering. Summary of the Invention

[0007] To address the aforementioned technical problems, the present invention provides a multicolor electrochromic device, comprising a transparent bottom electrode layer, a photonic crystal layer, an electrochromic layer, an electrolyte layer, and a transparent top electrode layer stacked sequentially.

[0008] The material of the photonic crystal layer is selected from one or more of polymer microspheres, silica microspheres, phase-separable block polymers, and liquid crystals; when the material of the photonic crystal layer is a combination of multiple photonic crystal materials, the photonic crystal layer will exhibit different structural colors on the front and back sides;

[0009] The electrochromic layer is made of poly(3,4-ethylenedioxythiophene), poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, polyaniline, polypyrrole, triphenylamine, poly(3,4-propylenedioxythiophene), violet, metal phthalocyanine and its derivatives.

[0010] Preferably, the thickness of the electrochromic layer is 200-800 nm.

[0011] Preferably, the thickness of the photonic crystal layer is 1-10 μm.

[0012] Preferably, the electrolyte layer comprises an electrolyte solution; the electrolyte solution is filled in the insulating frame.

[0013] Specifically, the electrolyte layer is prepared by encapsulating it along the edge with encapsulating adhesive and insulating strips that control the glass gap (the glass gap refers to the distance between the photonic crystal and the electrochromic composite layer and the top electrode) to form an insulating frame, and defining a cavity within the insulating frame; then coating it with a 100μm doctor blade and filling the cavity with the prepared electrolyte solution.

[0014] Furthermore, the solute in the electrolyte includes one or more of LiPF6, LiBF4, LiClO4, LiAsF6, LiCF3SO3, LiN(CF3SO2)2, LiC(CF3SO2)3, LiFSI, LiBOB, and LiTFSI.

[0015] Preferably, the concentration of the solute in the electrolyte is 10. -5 -10 -3 mol / L.

[0016] Preferably, the insulating frame is made of organic epoxy resin.

[0017] Preferably, the coating method is brushing or spraying.

[0018] Preferably, the electrochromic layer is obtained by spin coating or spray coating followed by heating.

[0019] Preferably, the thickness of the electrolyte layer is 100-500 μm.

[0020] Preferably, the transparent bottom electrode layer comprises ITO (indium tin oxide) conductive glass, zinc oxide conductive film, fluorine tin oxide conductive film, metal mesh layer, and nano-conductive silver wire coating layer.

[0021] Preferably, the transparent top electrode layer comprises ITO conductive glass, zinc oxide conductive film, fluorine tin oxide conductive film, metal mesh layer and nano-conductive silver wire coating layer.

[0022] Preferably, various electrochromic materials can be transferred to the desired substrate or substrate-free surface by peeling and transfer method.

[0023] Furthermore, when the transparent bottom electrode layer is a metal mesh layer, a substrate is also provided at the bottom of the transparent bottom electrode layer.

[0024] Furthermore, the thickness of the metal mesh layer is 500-1000 nm.

[0025] The present invention also provides a method for preparing the above-mentioned multicolor electrochromic device, comprising the following steps:

[0026] S1: Coating a photonic crystal paste onto a transparent bottom electrode layer to obtain a photonic crystal layer; the photonic crystal paste comprises one or more of polymer microspheres, silica microspheres, phase-separable block polymers, and liquid crystals;

[0027] S2: Composite an electrochromic material onto the top of the photonic crystal layer to obtain an electrochromic layer; the electrochromic material is selected from one or more of poly(3,4-ethylenedioxythiophene), poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, polyaniline, polypyrrole, triphenylamine, poly(3,4-propylenedioxythiophene), violetin, metal phthalocyanine and its derivatives;

[0028] S3: After encapsulating the top of the electrochromic layer, fill it with electrolyte to obtain an electrolyte layer;

[0029] S4: Composite a transparent top electrode layer onto the top of the electrolyte layer to obtain the multicolor electrochromic device.

[0030] Preferably, the above-mentioned preparation method includes the step of patterning the multicolor electrochromic device.

[0031] Furthermore, step S1 also includes a patterning operation on the transparent bottom electrode layer.

[0032] Furthermore, step S1 also includes a patterning operation on the photonic crystal layer.

[0033] Specifically, it also includes the operation of patterning the photonic crystal layer by stripping and transferring the image.

[0034] Furthermore, step S2 also includes a patterning operation on the electrochromic layer.

[0035] Specifically, step S2 also includes a peeling and transfer operation on the electrochromic material.

[0036] It is conceivable that the patterning process in the above steps can include any combination of a transparent bottom electrode layer, a photonic crystal layer, and an electrochromic layer.

[0037] Furthermore, the above-mentioned patterning methods include inkjet printing, flexographic printing, gravure printing, screen printing, etching, or solvent treatment.

[0038] Furthermore, the screen printing employs a photomask. During patterning using screen printing, the upper layer of material fills the gaps in the lower photomask.

[0039] Furthermore, the metal mesh layer is a silver nanowire bottom electrode layer.

[0040] Specifically, the patterning method for the silver nanowire bottom electrode layer is screen printing.

[0041] Specifically, the patterning process for the ITO conductive glass is as follows: a photosensitive layer is formed on the ITO glass, and this photosensitive layer needs to cover the patterned ITO layer. A patterned first photosensitive layer is obtained through exposure, lithography, and development. The ITO pattern of the first photosensitive layer is transferred to the first ITO layer using an etching method to form the desired patterned ITO layer. Various patterned electrochromic devices can be transferred to the desired substrate using a stripping transfer method.

[0042] Preferably, the material of the photonic crystal layer is a PS@SiO2 nanosphere emulsion, and the preparation method of the PS@SiO2 nanosphere emulsion includes the following steps:

[0043] (1) DMC (methacryloyloxyethyltrimethylammonium chloride), styrene and initiator were added to an aqueous ethanol solution and heated under a protective atmosphere to obtain cationic PS microspheres;

[0044] (2) The cationic PS microspheres and silane coupling agent were added to ammonia water, and after the reaction, they were dispersed in alcohol to obtain the PS@SiO2 nanosphere emulsion.

[0045] In step (2), the silane coupling agent is γ-methacryloxypropyltrimethoxysilane (KH570).

[0046] In step (2), the reaction time is 5-7 hours.

[0047] Preferably, in step (1), the protective atmosphere is nitrogen.

[0048] Preferably, in step (1), the initiator is AIBN (azobisisobutyl nitrile).

[0049] Preferably, in step (1), the heating reaction temperature is 60-80℃ and the reaction time is 5-7h.

[0050] Preferably, in the ethanol-water solution, the mass ratio of ethanol to water is 2-4:1.

[0051] Preferably, in step (1), the mass ratio of styrene to initiator is 10:0.1-0.5.

[0052] Furthermore, in the PS@SiO2 nanosphere emulsion, the diameter of the PS@SiO2 nanospheres is 180-280 nm.

[0053] The technical solution of the present invention has the following advantages compared with the prior art:

[0054] This invention provides a method for preparing a novel patterned photonic crystal type multicolor electrochromic thin film device. By introducing an electrochromic@photonic crystal composite thin film into a traditional electrochromic device, the effect of large-area, patterned device display can be achieved.

[0055] The electrochromic composite film prepared in this invention uses methods such as inkjet printing, flexographic printing, gravure printing, screen printing, etching, or solvent treatment to print electrochromic materials onto a photonic crystal composite substrate. The color of different photonic crystals can be controlled by adjusting their size. Introducing a composite photonic crystal electrochromic layer effectively solves the problem of single-color electrochromic devices. Compared to traditional patterned electrochromic devices, this invention provides a simpler approach to patterning photonic crystal layers, enabling the fabrication of electrochromic devices on different substrates through transfer printing. This fabrication method is convenient, fast, simple, and low-cost, providing a possible method for the industrial production of large-area patterned multi-color electrochromic devices. Attached Figure Description

[0056] Figure 1 The images show the colored and faded states of the multicolor electrochromic device in Example 1.

[0057] Figure 2 The images show the colored and faded states of the multicolor electrochromic device in Example 3.

[0058] Figure 3 This is a schematic diagram of the transparent bottom electrode layer of the multicolor electrochromic device in Example 4;

[0059] Figure 4 This is a schematic diagram of the process of screen printing a photonic crystal layer on the transparent bottom electrode layer of a multicolor electrochromic device using a photomask in Example 4.

[0060] Figure 5 This is a schematic diagram illustrating the patterning process of the photonic crystal layer in Example 4;

[0061] Figure 6 This is a schematic diagram of printing an electrochromic layer on a photonic crystal layer in Example 4;

[0062] Figure 7 This is a schematic diagram of an electrolyte layer coated on an electrochromic layer using rectangular organic epoxy resin separators, as shown in Example 4.

[0063] Figure 8 This is a schematic diagram of the structure of the multicolor patterned electrochromic device in Example 4;

[0064] Figure 9 This is a schematic diagram of the transparent bottom electrode layer of the multicolor electrochromic device in Example 5;

[0065] Figure 10 This is a schematic diagram of the process of printing a photonic crystal layer on the transparent bottom electrode layer of a multicolor electrochromic device in Example 5;

[0066] Figure 11 This is a schematic diagram of the electrochromic layer being screen-printed using a mask on the photonic crystal layer in Example 5.

[0067] Figure 12 This is a schematic diagram illustrating the patterning process of the electrochromic layer in Example 5;

[0068] Figure 13 This is a schematic diagram of an electrolyte layer coated on an electrochromic layer using rectangular organic epoxy resin partitions in Example 5.

[0069] Figure 14 This is a schematic diagram of the structure of the multicolor patterned electrochromic device in Example 5;

[0070] Figure 15 This is a schematic diagram of the substrate of the multicolor electrochromic device in Example 6;

[0071] Figure 16 This is a schematic diagram of the process of screen printing a silver nanowire bottom electrode layer on the substrate of a multicolor electrochromic device using a photomask in Example 6.

[0072] Figure 17 This is a schematic diagram of the patterning process achieved in the bottom electrode layer of silver nanowires in Example 6;

[0073] Figure 18This is a schematic diagram of printing a photonic crystal layer on the silver nanowire bottom electrode layer in Example 6;

[0074] Figure 19 This is a schematic diagram of printing an electrochromic layer on a photonic crystal layer in Example 6;

[0075] Figure 20 This is a schematic diagram of an electrolyte layer coated on an electrochromic layer using rectangular organic epoxy resin partitions in Example 6.

[0076] Figure 21 This is a schematic diagram of the structure of the multicolor patterned electrochromic device in Example 6;

[0077] Figure 22 This is a diagram of the transfer process of the multi-color patterned electrochromic device in Example 6.

[0078] Figure reference numerals: 10-Transparent bottom electrode layer, 11-Mask, 12-Photonic crystal layer, 13-Electrochromic layer, 14-Electrolyte layer, 15-Transparent top electrode layer, 16-Silver nanowire bottom electrode layer, 20-Insulating frame, 30-Substrate. Detailed Implementation

[0079] The present invention will be further described below with reference to specific embodiments, so that those skilled in the art can better understand and implement the present invention, but the embodiments are not intended to limit the present invention.

[0080] Example 1: Preparation and processing scheme 1 of PS@SiO2 composite nanospheres in a photonic crystal layer

[0081] Monodisperse cationic PS microspheres were prepared by dispersion polymerization. 60 parts by weight of ethanol and 20 parts by weight of deionized water were used as the medium. 15 parts by weight of styrene and 0.3 parts by weight of azobisisobutylnitrile (AIBN) were added as initiators, and an appropriate amount of methacryloyloxyethyltrimethylammonium chloride (DMC) was added as a comonomer. The reaction was carried out at 70°C under nitrogen protection for 6 hours. After centrifugation, the reaction product was washed several times with ethanol, and finally, the PS microspheres were dispersed in 30 parts by weight of anhydrous ethanol.

[0082] Core-shell structured PS@SiO2 composite nanospheres were prepared using the Stober method. A specific amount of PS was diluted to a dispersion with a solid content of 15%. 5.5 parts by weight of this dispersion were weighed and, under magnetic stirring, 60 parts by weight of deionized water were added dropwise. After stirring for 15 min, appropriate amounts of ammonia and 35 parts by weight of deionized water were added. After stirring for another 15 min, 2 parts by weight of γ-methacryloyloxypropyltrimethoxysilane (KH570) were added dropwise, and the reaction was allowed to proceed for 6 h. The reaction product was centrifuged and washed three times with anhydrous ethanol. Finally, the PS@SiO2 composite nanospheres were dispersed in 25 parts by weight of anhydrous ethanol.

[0083] The diameter of the obtained PS@SiO2 composite nanospheres is 220-240 nm.

[0084] A PS@SiO2 composite film with a five-pointed star pattern was prepared by screen printing.

[0085] The pattern on the PS@SiO2 composite film is green.

[0086] The process of obtaining a polythiophene / PS@SiO2 electrochromic thin film using the above-mentioned PS@SiO2 composite nanospheres as a photonic crystal layer can be achieved by transferring patterned electrochromic devices onto the desired substrate using a "peel-off transfer" method. Both the transparent bottom electrode layer 10 and the transparent top electrode layer 15 are ITO glass substrates with sheet resistances of 5-25 Ω / sq and thicknesses of 100-200 nm.

[0087] Example 2: Preparation and treatment scheme 2 of PS@SiO2 composite nanospheres in photonic crystal layer

[0088] Monodisperse cationic PS microspheres were prepared by dispersion polymerization. 60 parts by weight of ethanol and 20 parts by weight of deionized water were used as the medium. 10 parts by weight of styrene and 0.2 parts by weight of azobisisobutyl nitrile (AIBN) were added as initiators, and an appropriate amount of methacryloyloxyethyltrimethylammonium chloride (DMC) was added as a comonomer. The reaction was carried out at 70°C under nitrogen protection for 6 hours. After centrifugation, the reaction product was washed several times with ethanol, and finally, the PS microspheres were dispersed in 30 parts by weight of anhydrous ethanol.

[0089] Core-shell structured PS@SiO2 composite nanospheres were prepared using the Stober method. A specific amount of PS was diluted to a dispersion with a solid content of 9%. 5 parts by weight of this dispersion were weighed and, under magnetic stirring, 60 parts by weight of deionized water were added dropwise. After stirring for 15 min, a suitable amount of ammonia and 30 parts by weight of deionized water were added. After stirring for another 15 min, 1 part by weight of γ-glycidoxypropyltrimethoxysilane (KH560) was added dropwise, and the reaction was allowed to proceed for 6 h. The reaction product was centrifuged and washed three times with anhydrous ethanol. Finally, the PS@SiO2 composite nanospheres were dispersed in 25 parts by weight of anhydrous ethanol.

[0090] The diameter of the obtained PS@SiO2 composite nanospheres is 180-200 nm;

[0091] A PS@SiO2 composite film with a mouse pattern was prepared by inkjet printing.

[0092] The PS@SiO2 composite film pattern is blue-green.

[0093] The process of obtaining a polyaniline / PS@SiO2 electrochromic thin film using the above-mentioned PS@SiO2 composite nanospheres as a photonic crystal layer can be achieved by transferring patterned electrochromic devices onto the desired substrate using a "peel-off transfer" method. Both the transparent bottom electrode layer 10 and the transparent top electrode layer 15 are ITO glass substrates with sheet resistances of 5-25 Ω / sq and thicknesses of 100-200 nm.

[0094] Example 3: Preparation and treatment scheme 3 of PS@SiO2 composite nanospheres in photonic crystal layer

[0095] Monodisperse cationic PS microspheres were prepared by dispersion polymerization. 90 parts by weight of ethanol and 30 parts by weight of deionized water were used as the medium. 20 parts by weight of styrene and 0.4 parts by weight of azobisisobutylnitrile (AIBN) were added as initiators, and an appropriate amount of methacryloyloxyethyltrimethylammonium chloride (DMC) was added as a comonomer. The reaction was carried out at 70°C under nitrogen protection for 6 hours. After centrifugation, the reaction product was washed several times with ethanol, and finally, the PS microspheres were dispersed in 30 parts by weight of anhydrous ethanol.

[0096] Core-shell structured PS@SiO2 composite nanospheres were prepared using the Stober method. A specific amount of PS was diluted to a dispersion with a solid content of 9%. 5 parts by weight of this dispersion were weighed and, under magnetic stirring, 60 parts by weight of deionized water were added dropwise. After stirring for 15 min, a suitable amount of ammonia and 30 parts by weight of deionized water were added. After stirring for another 15 min, 1 part by weight of vinyltrimethoxysilane (KH171) was added dropwise, and the reaction was allowed to proceed for 6 h. The reaction product was centrifuged and washed three times with anhydrous ethanol. Finally, the PS@SiO2 composite nanospheres were dispersed in 25 parts by weight of anhydrous ethanol.

[0097] The diameter of PS@SiO2 composite nanospheres is 230-250 nm.

[0098] A PS@SiO2 composite film with an elephant pattern was prepared by gravure printing.

[0099] The PS@SiO2 composite film pattern is orange-red.

[0100] The process of obtaining a polypyrrole / PS@SiO2 electrochromic thin film by using the above-mentioned PS@SiO2 composite nanospheres as a photonic crystal layer can be achieved by transferring patterned electrochromic devices onto the desired substrate using a "peel-off transfer" method. Both the transparent bottom electrode layer 10 and the transparent top electrode layer 15 are ITO glass substrates with sheet resistances of 5-25 Ω / sq and thicknesses of 100-200 nm.

[0101] Example 4: Fabrication of Electrochromic Devices (Patterned Photonic Crystal Layer)

[0102] (1) First, the photonic crystal layer 12 is printed on the transparent bottom electrode layer 10, and the electrochromic device is patterned by screen printing through the PDMS mask 11.

[0103] (2) The electrochromic layer 13 is spin-coated onto the photonic crystal layer 12 to obtain a composite layer;

[0104] (3) An electrolyte layer 14 is formed by injecting an electrolyte sol between the electrochromic layer 13 and the transparent top electrode layer 15 using a rectangular insulating frame 20 (made of organic epoxy resin); wherein the electrolyte sol is an organic lithium-ion sol, and the electrochromic layer 13 will cover the gaps of the patterned photonic crystal layer 12.

[0105] (4) Cover with a transparent top electrode layer and encapsulate to obtain an electrochromic device.

[0106] The patterned photonic crystal type multicolor electrochromic device consists of, from top to bottom, a transparent top electrode layer 15, an electrolyte layer 14, an electrochromic layer 13, a photonic crystal layer 12, and a transparent bottom electrode layer 10.

[0107] The electrochromic layer 13 is made of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, the photonic crystal layer 12 is made of PS@SiO2, the transparent bottom electrode layer 10 is an ITO glass layer, and both the electrochromic layer 13 and the photonic crystal layer 12 are printed using screen printing. The patterning method is to use a mask 11 to screen print the photonic crystal layer 12.

[0108] This embodiment provides a patterned photonic crystal layer as a patterned electrochromic device, the structure of which is as follows: Figure 8 As shown.

[0109] Example 5: Fabrication of an electrochromic device (patterned electrochromic layer)

[0110] (1) First, the photonic crystal layer 12 is coated on the transparent bottom electrode layer 10;

[0111] (2) The electrochromic layer 13 is printed and laminated onto the photonic crystal layer 12 using a PDMS mask to pattern the electrochromic layer 13.

[0112] (3) An electrolyte layer 14 is formed by injecting an electrolyte sol between the electrochromic layer 13 and the transparent top electrode layer 15 by separating them with a rectangular insulating frame 20 (made of organic epoxy resin); wherein the electrolyte sol is an organic lithium-ion sol, and the electrolyte layer 14 will cover the gaps of the patterned electrochromic layer 13.

[0113] (4) Cover with a transparent top electrode layer and encapsulate to obtain an electrochromic device.

[0114] The patterned photonic crystal type multicolor electrochromic device consists of, from top to bottom, a transparent top electrode layer 15, an electrolyte layer 14, an electrochromic layer 13, a photonic crystal layer 12, and a transparent bottom electrode layer 10.

[0115] The electrochromic layer 13 is made of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, the photonic crystal layer 12 is made of PS@SiO2, the transparent bottom electrode layer 10 is an ITO glass layer, and both the electrochromic layer 13 and the photonic crystal layer 12 are printed using screen printing. The patterning method is to use a mask 11 to screen print the electrochromic layer 13.

[0116] This embodiment provides a patterned electrochromic layer as a patterned electrochromic device, and its constituent components are structured as follows: Figure 14 As shown.

[0117] Example 6: Fabrication of an electrochromic device (monolithic transfer of silver nanowires)

[0118] (1) First, the silver nanowire bottom electrode layer 16 is printed on the substrate 30 through a mask 11;

[0119] (2) Then the photonic crystal layer 12 is coated onto the silver nanowire bottom electrode layer 16 by screen printing.

[0120] (3) The electrochromic layer 13 is applied to the photonic crystal layer 12 by screen printing. The electrochromic layer 13 and the transparent top electrode layer 15 are separated by a rectangular insulating frame 20 (made of organic epoxy resin). An electrolyte layer 14 is formed by injecting an electrolyte sol. The electrolyte sol is an organic lithium-ion sol. The photonic crystal layer 12 will cover the gaps of the patterned silver nanowire bottom electrode layer 16.

[0121] (4) The device is assembled by printing silver nanowires;

[0122] (5) The patterned electrochromic device is transferred by means of transfer printing: the device is immersed in a glass container containing 15% hydrochloric acid for 60 minutes, the substrate is completely separated from the patterned device, and finally placed in a petri dish containing pure water and dried in the air. A suitable substrate is selected for transfer printing.

[0123] (6) Cover with a transparent top electrode layer (silver nanowire bottom electrode layer 16) and encapsulate to obtain an electrochromic device.

[0124] The patterned photonic crystal type multicolor electrochromic device consists of, from top to bottom, a silver nanowire bottom electrode layer 16, an electrolyte layer 14, an electrochromic layer 13, a photonic crystal layer 12, and a silver nanowire bottom electrode layer 16.

[0125] The electrochromic layer 13 is made of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, the photonic crystal layer 12 is made of PS@SiO2, and the bottom electrode is a silver nanowire bottom electrode layer 16. Both the electrochromic layer 13 and the photonic crystal layer 12 are printed by screen printing.

[0126] This embodiment provides a method for integrally transferring an electrochromic device and using silver nanowires as patterned electrochromic devices. The component structure is as follows: Figure 21 .

[0127] Example 7: Fabrication of an electrochromic device (patterned photonic crystal layer and electrochromic layer)

[0128] (1) First, the photonic crystal layer 12 is coated on the transparent bottom electrode layer 10, and patterning is achieved by screen printing through the PDMS mask 11.

[0129] (2) The electrochromic layer 13 is coated onto the photonic crystal layer 12 using a PDMS mask 11 to obtain a composite layer.

[0130] (3) An electrolyte layer 14 is formed by injecting an electrolyte sol between the electrochromic layer 13 and the transparent top electrode layer 15, which are separated by a rectangular insulating frame 20 (made of organic epoxy resin); wherein the electrolyte sol is an organic lithium-ion sol.

[0131] (4) Cover with a transparent top electrode layer and encapsulate to obtain an electrochromic device.

[0132] The patterned photonic crystal type multicolor electrochromic device consists of, from top to bottom, a transparent top electrode layer 15, an electrolyte layer 14, an electrochromic layer 13, a photonic crystal layer 12, and a transparent bottom electrode layer 10.

[0133] The electrochromic layer 13 is made of poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, the photonic crystal layer 12 is made of PS@SiO2, and the transparent bottom electrode layer 10 is an ITO glass layer. Both the electrochromic layer 13 and the photonic crystal layer 12 are applied by screen printing.

[0134] Example 8: Fabrication of an electrochromic device (monolithic transfer of silver nanowires and patterning of a photonic crystal layer)

[0135] (1) First, the silver nanowire bottom electrode layer 16 is printed on the substrate 30 through a mask 11;

[0136] (2) The photonic crystal layer 12 is printed on the transparent bottom electrode layer 10, and the patterning of the photonic crystal layer 12 is achieved by screen printing through the PDMS mask 11.

[0137] (3) The electrochromic layer 13 is applied onto the photonic crystal layer 12 by screen printing;

[0138] (4) An electrolyte layer 14 is formed by injecting an electrolyte sol between the electrochromic layer 13 and the transparent top electrode layer 15, separated by a rectangular insulating frame 20 (made of organic epoxy resin); wherein the electrolyte sol is an organic lithium-ion sol. Finally, the device is assembled by printing silver nanowires.

[0139] (5) The patterned electrochromic device is transferred by means of immersing the device in a glass container containing 15% hydrochloric acid for 60 minutes, the substrate is completely separated from the patterned device, and finally placed in a petri dish containing pure water and dried in the air. A suitable substrate is selected for transfer.

[0140] (6) Cover with a transparent top electrode layer (silver nanowire bottom electrode layer 16) and encapsulate to obtain an electrochromic device.

[0141] The patterned photonic crystal type multicolor electrochromic device consists of, from top to bottom, a silver nanowire bottom electrode layer 16, an electrolyte layer 14, an electrochromic layer 13, a photonic crystal layer 12, and a silver nanowire bottom electrode layer 16.

[0142] The electrochromic layer 13 is a poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid layer, the photonic crystal layer 12 is PS@SiO2, and the bottom electrode is a silver nanowire bottom electrode layer 16. Both the electrochromic layer 13 and the photonic crystal layer 12 are printed using screen printing.

[0143] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for fabricating a multicolor electrochromic device, characterized in that, Includes the following steps: S1: Coating a photonic crystal paste onto the transparent bottom electrode layer (10) to obtain a photonic crystal layer (12); the photonic crystal paste is selected from a combination of polystyrene microspheres and silica microspheres; step S1 also includes a patterning operation of the photonic crystal layer (12) by peeling and transfer method; S2: Composite an electrochromic material onto the top of the photonic crystal layer (12) to obtain an electrochromic layer (13); the electrochromic material is selected from one or more of poly(3,4-ethylenedioxythiophene), poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, polyaniline, polypyrrole, triphenylamine, poly(3,4-propylenedioxythiophene), violet, metal phthalocyanine and its derivatives; S3: After encapsulating the top of the electrochromic layer (13), fill it with electrolyte to obtain an electrolyte layer (14). S4: Composite a transparent top electrode layer (15) onto the top of the electrolyte layer (14) to obtain the multicolor electrochromic device.

2. The method for preparing the multicolor electrochromic device as described in claim 1, characterized in that, The electrolyte layer (14) is selected from one or more of urea-choline chloride, diethylenetriamine-choline chloride, ethylene glycol-choline chloride and malic acid-choline chloride, and is a mixture of one or more of LiPF6, LiBF4, LiClO4, LiAsF6, LiCF3SO3, LiN(CF3SO2)2, LiC(CF3SO2)3, LiFSI and LiBOB and LiTFSI.

3. The method for preparing the multicolor electrochromic device as described in claim 1, characterized in that, Step S1 also includes a patterning operation on the transparent bottom electrode layer (10).

4. The method for preparing the multicolor electrochromic device as described in claim 3, characterized in that, The patterning process can be inkjet printing, flexographic printing, gravure printing, screen printing, etching, or solvent treatment.

5. The method for preparing the multicolor electrochromic device as described in claim 1, characterized in that, Step S2 also includes a patterning process for the electrochromic layer (13); the patterning process can be inkjet printing, flexographic printing, gravure printing, screen printing, etching, or solvent treatment.

6. The method for preparing the multicolor electrochromic device as described in claim 5, characterized in that, Step S2 also includes a peeling and transfer operation on the electrochromic material.

7. A multicolor electrochromic device prepared by the preparation method according to any one of claims 1-6, characterized in that, It includes a transparent bottom electrode layer (10), a photonic crystal layer (12), an electrochromic layer (13), an electrolyte layer (14), and a transparent top electrode layer (15) stacked in sequence. The material of the photonic crystal layer (12) is selected from a combination of polystyrene microspheres and silica microspheres; The electrochromic layer (13) is made of one or more of the following materials: poly(3,4-ethylenedioxythiophene), poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, polyaniline, polypyrrole, triphenylamine, poly(3,4-propylenedioxythiophene), violet, metal phthalocyanine and its derivatives. The transparent bottom electrode layer (10) is selected from ITO conductive glass, zinc oxide conductive film, fluorine tin oxide conductive film, metal mesh layer or nano-conductive silver wire coating layer; the thickness of the metal mesh layer is 500-1000nm, the thickness of the electrochromic layer (13) is 200-800nm, and the thickness of the photonic crystal layer (12) is 1-10μm.

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