Transparent flexible electrode and method for manufacturing the same

Abstract

The present application relates to the technical fields of flexible electronic device processing, and provides a transparent flexible electrode and a preparation method thereof, the transparent flexible electrode comprising: a polymer substrate composed of a transparent flexible polymer material; a first aluminum-doped zinc oxide particle layer, which is coated on the polymer substrate and used to enhance the adhesion of a silver nanowire network layer to the polymer substrate; the silver nanowire network layer, which is coated on the first aluminum-doped zinc oxide particle layer and used to realize the conductivity of the electrode; and a second aluminum-doped zinc oxide particle layer, which is coated on the silver nanowire network layer and used to enhance the mechanical properties of the silver nanowire network layer. The method realizes the preparation of the transparent flexible electrode with high conductivity, high light transmittance and high stability at low cost.

Description

Technical Field

[0001] This invention relates to the field of flexible electronic device fabrication technology, and in particular to a transparent flexible electrode and its fabrication method. Background Technology

[0002] In nature, transparent materials (such as glass) are generally non-conductive, while conductive materials (such as metals) are generally opaque. According to the principles of semiconductor physics, in highly transparent materials like glass, the energy bands containing valence electrons are completely filled. Empty bands have much higher energy than filled bands, confining the valence electrons within them, resulting in poor conductivity. From an energy perspective, transparency means that electrons in the material cannot absorb the energy corresponding to visible light and undergo transitions. Therefore, from a physical standpoint, the transparency and conductivity of materials are generally incompatible.

[0003] However, there is a wide demand for flexible transparent conductive films in fields such as advanced energy, flexible displays, and biomedicine. For example, in the field of advanced energy, in the research of organic solar cells, to realize stretchable solar cells for use in cutting-edge devices such as wearable electronic devices, it is necessary to use transparent flexible electrodes as the top electrode structure of the cell. This ensures that sunlight does not enter during the conversion and conduction of solar energy into electrical energy, and does not affect the energy conversion efficiency of the solar cell.

[0004] In the field of flexible displays, in order to realize flexible organic light-emitting diodes (f-OLEDs), it is necessary to use transparent flexible electrodes with high conductivity and high transmittance as their anode materials to achieve both high-efficiency carrier transport and high-efficiency light emission.

[0005] In the biomedical field, the applications of transparent flexible electrodes are even more clearly defined. For example, in electroretinography (ERG) (an important visual electrophysiological test that assesses retinal function by measuring the electrical signals induced by light stimulation in the cornea), transparent flexible electrodes are needed as corneal electrodes to accurately measure the weak electrical signals transmitted from the retina to the cornea without affecting the entry of light into the pupil during light stimulation. Similarly, in some cutting-edge optogenetic research, transparent flexible electrodes are needed as electrocorticography (ECoG) signal acquisition electrodes to accurately acquire ECoG signals in the cerebral cortex while neural light stimulation is being performed.

[0006] For the above-mentioned demand scenarios, the most commonly used transparent electrode is indium tin oxide (ITO) transparent electrode. Its sheet resistance is generally tens of ohms, and its transmittance in the visible light wavelength range is generally 70%-80%, which meets the application requirements of most transparent electrodes. However, there are several problems: (1) ITO electrodes are hard and brittle, and slight bending can cause them to lose conductivity; (2) The conventional sputtering temperature of ITO is about 200℃, and the processing is relatively complicated; (3) Indium is a rare metal material, and the cost of ITO raw materials is high, and the supply is limited; (4) There is some controversy regarding the biocompatibility of indium tin oxide.

[0007] Therefore, in recent years, in order to replace traditional transparent electrodes such as ITO, the method of preparing transparent flexible electrodes based on materials such as carbon nanotubes, MXENE, metal nanomaterials, conductive polymers, and graphene has received widespread attention. Using these advanced materials, but still the following problems exist: (1) Unsatisfactory light transmittance - for example, electrodes prepared by PEDOT:PSS and related materials are not completely colorless and transparent, often with light blue, light gray and other colors, which have a significant impact on the light transmittance in applications such as ERG corneal electrodes; (2) Complex preparation method - involves complex process conditions such as high temperature, vacuum, sputtering, etc., and the steps are complicated, making patterning difficult; (3) Incompatible with curved structures - for curved substrates such as ERG corneal electrodes, conventional processing methods cannot prepare curved electrodes compatible with them; (4) High preparation cost - special materials such as graphene are expensive, and sputtering and other processes involve large equipment, all of which will increase the preparation cost of transparent flexible electrodes. Summary of the Invention

[0008] This invention provides a transparent flexible electrode and its preparation method, which solves the problems of poor bending resistance and high preparation cost of traditional transparent electrodes in the prior art. Based on the transparent flexible electrode preparation method of two low-cost nanomaterials, aluminum-doped zinc oxide and silver nanowires, a transparent flexible electrode with high conductivity, high transmittance and high stability can be prepared at low cost.

[0009] This invention provides a transparent flexible electrode, comprising: a polymer substrate composed of a transparent flexible polymer material; a first aluminum-doped zinc oxide particle layer coated on the polymer substrate to enhance the adhesion of a silver nanowire network layer to the polymer substrate; a silver nanowire network layer coated on the first aluminum-doped zinc oxide particle layer to achieve conductivity of the electrode; and a second aluminum-doped zinc oxide particle layer coated on the silver nanowire network layer to enhance the mechanical properties of the silver nanowire network layer.

[0010] According to the transparent flexible electrode provided by the present invention, the transparent flexible electrode further includes: a patterned mask layer, the patterned mask layer being formed by a patterning process and adhered to the polymer substrate.

[0011] The present invention also provides a method for preparing a transparent flexible electrode, comprising: pretreating a transparent flexible polymer substrate to improve its surface adhesion; preheating the pretreated polymer substrate; spraying an aluminum-zinc oxide aqueous dispersion onto the preheated polymer substrate; performing a first annealing treatment on the polymer substrate sprayed with the aluminum-zinc oxide aqueous dispersion to obtain a first aluminum-zinc oxide particle layer; spraying a silver nanowire aqueous dispersion onto the first aluminum-zinc oxide particle layer; performing a second annealing treatment on the first aluminum-zinc oxide particle layer sprayed with the silver nanowire aqueous dispersion to obtain a silver nanowire network; spraying an aluminum-zinc oxide aqueous dispersion onto the silver nanowire network layer to cover the silver nanowire network layer and encapsulate the silver nanowire junctions of the silver nanowire network layer; and performing a third annealing treatment on the silver nanowire network layer sprayed with the aluminum-zinc oxide aqueous dispersion to obtain a second aluminum-zinc oxide particle layer.

[0012] According to the transparent flexible electrode fabrication method provided by the present invention, the pretreatment of the transparent flexible polymer substrate to improve its surface adhesion includes: subjecting the polymer substrate to oxygen plasma pretreatment to improve the adhesion of the polymer substrate surface to nanomaterials.

[0013] According to the transparent flexible electrode fabrication method provided by the present invention, before pretreating the transparent flexible polymer substrate to improve its surface adhesion, the method further includes: depositing a layer of transparent flexible polymer substrate material on a rigid substrate to obtain a polymer substrate; after performing a third annealing treatment on the silver nanowire network layer sprayed with an aluminum-zinc oxide aqueous dispersion to obtain a second aluminum-zinc oxide particle layer, the method further includes: peeling the transparent flexible electrode from the rigid substrate, wherein the transparent flexible electrode comprises the polymer substrate, the first aluminum-zinc oxide particle layer, the silver nanowire network layer, and the second aluminum-zinc oxide particle layer.

[0014] According to the transparent flexible electrode preparation method provided by the present invention, the rigid substrate is coated with a layer of surfactant with hydrophilic properties before depositing a transparent flexible polymer substrate material and the coated surfactant is allowed to air dry; and the separation of the transparent flexible electrode from the rigid substrate includes: creating a small opening at the edge of the polymer substrate; adding an aqueous substance at the small opening, and using the hydrophilic properties and capillary action of the surfactant to separate the transparent flexible electrode from the rigid substrate.

[0015] According to the transparent flexible electrode preparation method provided by the present invention, the surfactant comprises a 5%-20% aqueous solution of a nonionic surfactant.

[0016] According to the transparent flexible electrode preparation method provided by the present invention, the first annealing treatment, the second annealing treatment and the third annealing treatment include annealing at a temperature of 150-200°C for 10-15 minutes; the concentration of the aluminum-doped zinc oxide aqueous dispersion is 0.5%-1%; the concentration of the silver nanowire aqueous dispersion is generally 0.1%-0.5%, and the number of spraying times of the silver nanowire aqueous dispersion is determined based on the thin-film resistance.

[0017] According to the transparent flexible electrode fabrication method provided by the present invention, before preheating the pretreated polymer substrate, the method further includes: placing the adhesive side of the first polymer tape facing upward on a laser processing stage, and laser-cutting out the desired pattern; carefully removing the mask of the first polymer tape from the laser processing stage and attaching it to the surface of the pretreated polymer substrate; and the step of separating the transparent flexible electrode from the rigid substrate further includes: removing the mask of the first polymer tape.

[0018] According to the transparent flexible electrode fabrication method provided by the present invention, before pretreating the polymer substrate to improve its surface adhesion, the method further includes: placing the adhesive side of the second polymer tape upwards on a laser processing stage and laser-cutting out the desired pattern; removing the mask of the second polymer tape from the laser processing stage and attaching it to the inner surface of the dried curved device; removing the area in the mask of the second polymer tape that needs to be sprayed with conductive material; using the completely dehydrated curved device as the polymer substrate; and after performing a third annealing treatment on the silver nanowire network layer sprayed with aluminum-zinc oxide aqueous dispersion to obtain a second aluminum-zinc oxide particle layer, the method further includes: removing the remaining mask of the second polymer tape to obtain the patterned transparent flexible curved electrode.

[0019] The transparent flexible electrode and its preparation method provided by this invention are based on two low-cost nanomaterials, aluminum-doped zinc oxide and silver nanowires, and realize the preparation of a transparent flexible electrode with high conductivity, high transmittance and high stability. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1This is a schematic diagram of the structure of the transparent flexible electrode provided by the present invention.

[0022] Figure 2 This is a schematic flowchart of the method for preparing the transparent flexible electrode provided by the present invention.

[0023] Figure 3 This is a schematic diagram of the fabrication process of the transparent flexible electrode provided by the present invention.

[0024] Figure 4 This is a schematic diagram of the fabrication process of the patterned transparent flexible electrode provided by the present invention.

[0025] Figure 5 This is a schematic diagram of the masked curved surface device provided by the present invention.

[0026] Figure 6 This is a schematic diagram of the thin-film resistance test site of the transparent flexible electrode provided by the present invention.

[0027] Figure 7 This is a schematic diagram showing the test results of the relationship between the number of coatings and the thin-film resistance of the transparent flexible electrode provided by this invention.

[0028] Figure 8 This is a schematic diagram showing the light transmittance test results of transparent flexible electrodes with different conductivity provided by the present invention.

[0029] Figure 9 This is a schematic diagram of the substrate adhesion test results of the transparent flexible electrode provided by the present invention.

[0030] Figure 10 This is a schematic diagram of the water immersion stability test results of the transparent flexible electrode provided by the present invention.

[0031] Figure 11 This is a schematic diagram of the test results for the reusability of the transparent flexible electrode provided by the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0033] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising,” “including,” or “including,” and similar terms mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or “connected,” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0034] The terminology involved in this invention will be briefly explained below.

[0035] The following is combined Figures 1-11 The transparent flexible electrode of the present invention and its preparation method are described.

[0036] Figure 1 This is a schematic diagram of the structure of the transparent flexible electrode provided by the present invention, as shown below. Figure 1 As shown, the transparent flexible electrode includes: a polymer substrate 101, which is composed of a transparent flexible polymer material; a first aluminum-doped zinc oxide particle layer 102, which is coated on the polymer substrate to enhance the adhesion of the silver nanowire network layer to the polymer substrate 101; a silver nanowire network layer 103, which is coated on the first aluminum-doped zinc oxide particle layer 102 to achieve the conductivity of the electrode; and a second aluminum-doped zinc oxide particle layer 104, which is coated on the silver nanowire network layer 103 to enhance the mechanical properties of the silver nanowire network layer.

[0037] The transparent flexible electrode provided by this invention can be used in flexible organic solar cells, flexible organic light-emitting diodes, electroretinography corneal electrodes, optogenetic electrocorticography recording electrodes, etc.

[0038] The transparent flexible electrode provided by the present invention includes a polymer substrate, a first aluminum-doped zinc oxide particle layer, a silver nanowire network layer and a second aluminum-doped zinc oxide particle layer. The preparation process is simple, and based on the roughening effect of aluminum-doped zinc oxide on the substrate and the coverage effect on the silver nanowire layer, the transparent flexible electrode achieves good substrate adhesion and reusability.

[0039] In some alternative implementations, the transparent flexible electrode also includes a patterned mask layer, which is formed by a patterning process and adhered to a polymer substrate.

[0040] The preparation method of the transparent flexible electrode provided by the present invention will be described below. The preparation method of the transparent flexible electrode described below can be referred to in correspondence with the transparent flexible electrode described above.

[0041] Figure 2 This is a schematic flowchart of the method for fabricating the transparent flexible electrode provided in the embodiments of this application, as shown below. Figure 2 As shown, it specifically includes: Step 201: Pre-treat the transparent and flexible polymer substrate to improve the adhesion of its surface.

[0042] In this embodiment, the transparent flexible polymer substrate can be made of materials such as Parylene-C, polyimide, or polyvinyl alcohol (PVA), and the thickness can be selected according to actual needs, for example, a size of 3-5 micrometers. Pretreatment can include oxygen plasma treatment, chemical treatment, etc.

[0043] Step 202: Preheat the pretreated polymer substrate; In this embodiment, preheating can be performed by means of a hot plate, oven, infrared, etc. For example, the pretreated polymer substrate can be preheated on a hot plate at 150-200°C for 5-10 minutes.

[0044] Step 203: Spray an aluminum-doped zinc oxide aqueous dispersion onto the preheated polymer substrate.

[0045] In this embodiment, an aluminum-doped zinc oxide (AZO) aqueous dispersion can be rapidly and briefly sprayed onto the substrate using a sprayer or similar equipment to increase the substrate's roughness.

[0046] Step 204: Perform a first annealing treatment on the polymer substrate sprayed with an aluminum-zinc oxide aqueous dispersion to obtain a first aluminum-zinc oxide particle layer.

[0047] In this embodiment, the temperature and time of the first annealing treatment can be set according to actual conditions.

[0048] Step 205: Spray a silver nanowire aqueous dispersion onto the first aluminum-doped zinc oxide particle layer.

[0049] In this embodiment, after the first annealing treatment, the silver nanowire (AgNWs) aqueous dispersion can be quickly and briefly sprayed onto the first aluminum-doped zinc oxide particle layer using equipment such as a sprayer.

[0050] Step 206: Perform a second annealing treatment on the first aluminum-doped zinc oxide particle layer coated with silver nanowire aqueous dispersion to obtain a silver nanowire network.

[0051] In this embodiment, the temperature and time of the second annealing process can be set according to actual conditions.

[0052] Step 207: Spray an aluminum-doped zinc oxide aqueous dispersion onto the silver nanowire network layer to cover the silver nanowire network layer and encapsulate the silver nanowire junctions in the silver nanowire network layer.

[0053] In this embodiment, after the second annealing treatment, an AZO aqueous dispersion can be quickly and briefly sprayed onto the substrate using a sprayer to encapsulate and cover the silver nanowire network.

[0054] Step 208: Perform a third annealing treatment on the silver nanowire network layer sprayed with aluminum-zinc oxide aqueous dispersion to obtain a second aluminum-zinc oxide particle layer.

[0055] In this embodiment, the temperature and time of the second annealing treatment can be set according to actual conditions, and the aluminum-doped zinc oxide particles can encapsulate part of the silver nanowire knots in the silver nanowire network.

[0056] The method for preparing transparent flexible electrodes provided by this invention achieves the preparation of transparent flexible electrodes with high conductivity, high transmittance, and high stability at low cost through a rapid spraying film forming method of real-time annealing of aluminum-doped zinc oxide and silver nanowire dispersion.

[0057] In some alternative implementations, the transparent, flexible polymer substrate is pretreated to improve its surface adhesion, including subjecting the polymer substrate to oxygen plasma pretreatment to enhance the adhesion of nanomaterials to the polymer substrate surface. The oxygen plasma treatment parameters can be 80W for 3-5 minutes.

[0058] In some alternative implementations, before pretreating the transparent flexible polymer substrate to improve its surface adhesion, the method further includes: depositing a layer of transparent flexible polymer substrate material on a rigid substrate to obtain a polymer substrate; performing a third annealing treatment on a silver nanowire network layer sprayed with an aluminum-zinc oxide aqueous dispersion to obtain a second aluminum-zinc oxide particle layer; and then further including: peeling the transparent flexible electrode from the rigid substrate, wherein the transparent flexible electrode includes the polymer substrate, the first aluminum-zinc oxide particle layer, the silver nanowire network layer, and the second aluminum-zinc oxide particle layer.

[0059] See Figure 3 , Figure 3 This is a schematic diagram of the fabrication process of the transparent flexible electrode provided by the present invention. Figure 3The process includes the following steps: (1) Prepare a clean rigid substrate 301. (2) Apply a layer of surfactant 302 to the clean rigid substrate 301 and wait for it to air dry naturally. (3) Deposit a layer of transparent flexible polymer substrate material 303 onto the rigid substrate 301. (4) Preheat and use a sprayer 304 to spray AZO aqueous dispersion 305 onto the substrate. (5) Anneal the substrate and then use a sprayer to spray AgNWs aqueous dispersion 306 onto the substrate. (6) Anneal the substrate and then use a sprayer to spray AZO aqueous dispersion 305 onto the substrate. (7) Use a knife to gently cut a small opening at the edge of the substrate and add a drop of pure water 307 to the opening. (8) Obtain a transparent flexible electrode 308 that is automatically peeled off from the rigid substrate.

[0060] In some alternative implementations, a layer of hydrophilic surfactant is applied to the rigid substrate before depositing the transparent flexible polymer substrate material and the applied surfactant is allowed to air dry; and the transparent flexible electrode is peeled off from the rigid substrate, including: creating a small opening at the edge of the polymer substrate; adding an aqueous substance at the small opening, and automatically peeling off the transparent flexible electrode from the rigid substrate by utilizing the hydrophilic properties of the surfactant and capillary action.

[0061] In this implementation, the rigid substrate can be a glass sheet, silicon wafer, or other substrate that is easy to process. A layer of surfactant 2 is applied to the clean rigid substrate 1 and allowed to air dry naturally. The rigid substrate 1 can be made of materials such as glass substrates or silicon wafers, and the surfactant 2 can be made of reagents such as Tween 20, Tween 80, or Span 85. After the third annealing treatment, a small opening can be gently made at the edge of the substrate with a knife. Then, a drop of pure water 7 is added to the opening. Due to the hydrophilic properties and capillary action of the surfactant, the water quickly spreads between the polymer substrate and the rigid substrate, thereby achieving automatic peeling of the flexible device 8 from the rigid substrate without damaging the device, without the need for a sacrificial layer.

[0062] This implementation proposes an automatic peeling method for thin film devices based on capillary force, which realizes the automatic peeling of flexible electronic devices, represented by transparent flexible electrodes, without sacrificial layers, further simplifying the process flow of transparent flexible electrode fabrication and improving production efficiency.

[0063] In some alternative implementations, the surfactant includes a 5%-20% aqueous solution of a nonionic surfactant. For example, a 5%-20% aqueous solution of a nonionic surfactant such as Tween or Span can be used.

[0064] In some optional implementations, the first, second, and third annealing processes include annealing at 150-200°C for 10-15 minutes; the concentration of the aluminum-doped zinc oxide aqueous dispersion is 0.5%-1%, and the number of spraying times depends on the actual situation, generally 3-5 times; the concentration of the silver nanowire aqueous dispersion is generally 0.1%-0.5%, and the number of spraying times of the silver nanowire aqueous dispersion can be determined based on the required thin-film resistance.

[0065] In some alternative implementations, before preheating the pretreated polymer substrate, the method further includes: placing the adhesive side of the first polymer tape face up on a laser processing stage and laser-cutting out the desired pattern; carefully removing the mask of the first polymer tape from the laser processing stage and attaching it to the surface of the pretreated polymer substrate; and peeling the transparent flexible electrode from the rigid substrate further includes: removing the mask of the first polymer tape.

[0066] In this implementation, to withstand the high temperatures in subsequent steps, a high-temperature resistant mask tape can be used, such as a 50-micron thick polyimide tape. As an example, the laser power for laser processing can be selected as 0.23W.

[0067] See Figure 4 , Figure 4 This is a schematic diagram of the fabrication process of the patterned transparent flexible electrode provided by the present invention. Figure 4 The process includes the following steps: (1) Prepare a clean hard substrate 401. (2) Apply a layer of surfactant 402 to the clean hard substrate 401 and wait for it to air dry naturally. (3) Deposit a layer of transparent flexible polymer substrate material 403 onto the hard substrate 401. (4) Place the polymer tape with the adhesive side facing up on the laser processing table, laser cut out the desired pattern, carefully remove the tape mask 409 from the laser processing table, and stick it to the surface of the polymer substrate 403. (5) Preheat, and use a sprayer 404 to spray AZO aqueous dispersion 405 onto the substrate. (6) Annealing treatment, and then use a sprayer to spray AgNWs aqueous dispersion 406 onto the substrate. (7) Annealing treatment, and then use a sprayer to spray AZO aqueous dispersion 405 onto the substrate. (8) Use a knife to gently cut a small opening at the edge of the substrate, and drop a drop of pure water 407 into the small opening. (9) A transparent flexible electrode 408 is obtained after automatic peeling from the rigid substrate.

[0068] In some alternative implementations, before pretreating the polymer substrate to improve its surface adhesion, the method further includes: placing the second polymer tape with the adhesive side facing up on a laser processing stage and laser-cutting out the desired pattern; removing the mask of the second polymer tape from the laser processing stage and attaching it to the inner surface of the dried curved device; removing the areas of the mask of the second polymer tape that need to be sprayed with conductive material; using the completely dehydrated curved device as the polymer substrate; and after performing a third annealing treatment on the silver nanowire network layer sprayed with aluminum-zinc oxide aqueous dispersion to obtain the second aluminum-zinc oxide particle layer, the method further includes: removing the remaining mask of the second polymer tape to obtain the patterned transparent flexible curved electrode. The curved device can be selected according to actual needs; for example, a contact lens device can be selected when fabricating a corneal electrode. This implementation proposes a new technical path for curved flexible electrodes. The application of this technology can bring new solutions to fields such as ophthalmic electrophysiological measurement, improving the quality of signal acquisition and the user experience for patients.

[0069] In this implementation, carefully peeling off the area in the adhesive tape mask that needs to be coated with conductive material will yield the following result: Figure 5 The masked contact mirror device can be placed on a hot plate at 180-200°C and, after complete dehydration, serve as a polymer substrate. Steps 201 to 208 in the above embodiments are then performed. After the third annealing process, the remaining adhesive tape mask can be carefully removed to obtain a patterned transparent flexible curved electrode.

[0070] The optimal thin-film resistance of the transparent flexible electrode described in this invention is approximately 7.5 Ω. Specific testing can be performed using the following steps: For the transparent flexible electrodes obtained by different spraying times of the AgNWs aqueous dispersion in the above embodiments, their resistance can be tested using an impedance analyzer and a probe platform. See [link to relevant documentation]. Figure 6 , Figure 6 This is a schematic diagram of the thin-film resistance testing sites for the transparent flexible electrode provided by this invention. For each electrode, the following can be selected: Figure 6 The resistance values ​​were measured at the six locations shown (dots of the same color indicate the positive and negative terminals of the same test location). The average of the six resistance values ​​was then taken as the thin-film resistance of this electrode sample. See also... Figure 7 , Figure 7 This is a schematic diagram showing the test results of the relationship between the number of coatings and the thin-film resistance of the transparent flexible electrode provided by this invention.

[0071] Figure 8This is a schematic diagram of the light transmittance test results of transparent flexible electrodes with different conductivity provided by the present invention. As an example, the specific test steps are as follows: Select 6 samples of each of the 4 types of transparent flexible electrodes with conductivity (thin layer resistance of 10Ω, 20Ω, 50Ω and 100Ω respectively) obtained in the above embodiment; place the above electrode samples in a UV-Vis spectrophotometer and measure their light transmittance at different wavelengths.

[0072] The present invention compares the substrate adhesion of the transparent flexible electrode (red curve) with the substrate adhesion of a conventional AgNWs transparent electrode (black curve) for example. Figure 9 As shown, the specific test steps are as follows: S1: Take 6 transparent flexible electrodes with a thin-film resistance of about 15Ω obtained in Example 1, test their substrate adhesion and take the average value; S2: For each sample, rub the sample surface once with a finger wearing a rubber glove, and then test its thin-film resistance; S3: Repeat step S2 10 times, test the thin-film resistance, and record it as a curve.

[0073] See Figure 10 , Figure 10 This is a schematic diagram of the water immersion stability test results of the transparent flexible electrode provided by the present invention. As an example, the specific test steps are as follows: S1: Take 6 transparent flexible electrodes with a thin-film resistance of about 15Ω obtained in the above embodiment, test their water immersion stability and take the average value; S2: For each sample, immerse it in deionized water at room temperature for about 3-5 minutes, take it out and dry it, and then test its thin-film resistance; S3: Repeat step S2 10 times, test the thin-film resistance, and record it as a curve.

[0074] See Figure 11 , Figure 11 This is a schematic diagram of the test results of the reusability characteristics of the transparent flexible electrode provided by the present invention. As an example, the specific test steps are as follows: S1: Take 6 transparent flexible electrodes with a thin-film resistance of about 15Ω obtained in the above embodiment, test their reusability characteristics and take the average value; S2: For each sample, wear it on the surface of a rabbit eye coated with ofloxacin eye ointment and carry out an ERG signal detection experiment for about 5-10 minutes; S3: After the experiment, remove the above electrode samples and dry them, and then test their thin-film resistance; S4: Repeat steps S2-S3 10 times, test the thin-film resistance, and record it as a curve.

[0075] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0076] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A transparent flexible electrode, characterized in that, include: A polymer substrate, wherein the polymer substrate is composed of a transparent flexible polymer material; A first aluminum-doped zinc oxide particle layer is coated on the polymer substrate to enhance the adhesion of the silver nanowire network layer to the polymer substrate. A silver nanowire network layer, which is coated on the first aluminum-doped zinc oxide particle layer, is used to achieve the conductivity of the electrode; A second aluminum-doped zinc oxide particle layer is applied over the silver nanowire network layer to enhance its mechanical properties.

2. The transparent flexible electrode according to claim 1, characterized in that, The transparent flexible electrode also includes: A patterned mask layer, formed by a patterning process, is adhered to the polymer substrate.

3. A method for preparing a transparent flexible electrode, characterized in that, include: Pretreatment of transparent and flexible polymer substrates is performed to improve the adhesion of their surfaces; The pretreated polymer substrate is preheated; Aluminum-zinc oxide aqueous dispersion was sprayed onto the preheated polymer substrate; The polymer substrate coated with an aluminum-zinc oxide aqueous dispersion is subjected to a first annealing treatment to obtain a first aluminum-zinc oxide particle layer. A silver nanowire aqueous dispersion was sprayed onto the first aluminum-doped zinc oxide particle layer. A second annealing treatment was performed on the first aluminum-doped zinc oxide particle layer sprayed with silver nanowire aqueous dispersion to obtain a silver nanowire network. Aluminum-doped zinc oxide aqueous dispersion is sprayed onto the silver nanowire network layer to cover the silver nanowire network layer and encapsulate the silver nanowire junctions of the silver nanowire network layer. The silver nanowire network layer coated with an aluminum-zinc oxide aqueous dispersion is subjected to a third annealing treatment to obtain a second aluminum-zinc oxide particle layer.

4. The method for preparing a transparent flexible electrode according to claim 3, characterized in that, The pretreatment of the transparent, flexible polymer substrate to improve its surface adhesion includes: The polymer substrate is pretreated with oxygen plasma to improve the adhesion of nanomaterials to the polymer substrate surface.

5. The method for preparing a transparent flexible electrode according to claim 3, characterized in that, Before pretreating the transparent, flexible polymer substrate to improve its surface adhesion, the method further includes: A polymer substrate is obtained by depositing a layer of transparent flexible polymer substrate material on a rigid substrate; After performing a third annealing treatment on the silver nanowire network layer coated with an aluminum-zinc oxide aqueous dispersion to obtain a second aluminum-zinc oxide particle layer, the method further includes: The transparent flexible electrode is separated from the rigid substrate. The transparent flexible electrode includes the polymer substrate, the first aluminum-doped zinc oxide particle layer, the silver nanowire network layer, and the second aluminum-doped zinc oxide particle layer.

6. The method for preparing a transparent flexible electrode according to claim 5, characterized in that, The rigid substrate is coated with a hydrophilic surfactant before the transparent flexible polymer substrate material is deposited, and the coated surfactant is allowed to air dry. And the separation of the transparent flexible electrode from the rigid substrate includes: A small opening is made at the edge of the polymer substrate; An aqueous substance is dripped into the small opening, and the transparent flexible electrode is automatically separated from the rigid substrate by utilizing the hydrophilic properties and capillary action of the surfactant.

7. The method for preparing a transparent flexible electrode according to claim 6, characterized in that, The surfactant includes a 5%-20% aqueous solution of a nonionic surfactant.

8. The method for preparing a transparent flexible electrode according to claim 3, characterized in that, The first annealing treatment, the second annealing treatment, and the third annealing treatment include annealing at a temperature of 150-200℃ for 10-15 minutes; the concentration of the aluminum-doped zinc oxide aqueous dispersion is 0.5%-1%; the concentration of the silver nanowire aqueous dispersion is generally 0.1%-0.5%, and the number of spraying times of the silver nanowire aqueous dispersion is determined based on the thin-film resistance.

9. The method for preparing a transparent flexible electrode according to any one of claims 5-8, characterized in that, Before preheating the pretreated polymer substrate, the method further includes: Place the first polymer tape with the adhesive side facing up on the laser processing table, and laser cut out the desired pattern; The mask of the first polymer tape was carefully removed from the laser processing stage and pasted onto the surface of the pretreated polymer substrate; The process of separating the transparent flexible electrode from the rigid substrate also includes: Remove the mask from the first polymer tape.

10. The method for preparing a transparent flexible electrode according to any one of claims 3-8, characterized in that, Prior to pretreating the polymer substrate to improve its surface adhesion, the method further includes: Place the second polymer tape with the adhesive side facing up on the laser processing table, and laser cut out the desired pattern. Remove the mask of the second polymer tape from the laser processing stage and attach it to the inner surface of the dried curved device; Remove the areas in the mask of the second polymer tape that require the application of conductive material; The curved device after complete water loss was used as a polymer substrate; After performing a third annealing treatment on the silver nanowire network layer coated with an aluminum-zinc oxide aqueous dispersion to obtain a second aluminum-zinc oxide particle layer, the method further includes: Remove the remaining mask from the second polymer tape to obtain a patterned transparent flexible curved electrode.

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