Electrochemical preparation methods, transfer methods and applications of patterned conductive polymer films

Abstract

This invention relates to the field of organic electronic materials technology, specifically to an electrochemical preparation method for patterned conductive polymer films, its transfer method, and its applications. The electrochemical preparation method includes: S1, sequentially performing a first washing, a first drying, and a UV ozone pretreatment on a conductive substrate; S2, performing photolithographic patterning on the pretreated conductive substrate from S1; S3, placing the photolithographically patterned conductive substrate from S2 into an electropolymer solution for in-situ electrochemical deposition to form a patterned conductive polymer film; S4, performing a second washing, adhesive removal, and a second drying on the patterned conductive polymer film. By employing photolithographic patterning of the conductive substrate, in-situ electrochemical deposition, and template transfer techniques, high-resolution, high-electrochemically active patterned conductive polymer films can be prepared and integrated with flexible substrates. The process is simple, highly controllable, suitable for large-scale production, and has broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of organic electronic materials technology, specifically to an electrochemical preparation method for patterned conductive polymer films, a transfer method thereof, and its application. Background Technology

[0002] Patterning technology for conductive polymer thin films is one of the core supporting technologies in the field of organic electronic materials and devices. Conductive polymer thin films such as polypyrrole and polythiophene are in high demand in flexible electronics, wearable devices, and other fields due to their stable conductivity, good flexibility, and precise functional control. With the development of related fields, single, flat conductive polymer thin films can no longer meet the requirements of conductivity in specific areas of devices and the integration of multiple components; therefore, patterned fabrication has become a key technological breakthrough.

[0003] Current methods for preparing conductive polymer film patterns mainly include printing and photolithography, but both have significant limitations. In printing methods, solution-based methods such as inkjet printing (e.g., CN201810128796.7), screen printing (e.g., CN201910703519.9), and 3D printing (e.g., CN202210882673.9) are affected by ink viscosity, surface tension, and printing precision. Ink formulations are sensitive, requiring precise matching of solvent, conductive polymer concentration, and binder ratio. Improper formulation can easily lead to uneven film formation and decreased conductivity. Furthermore, different substrates require customized inks, resulting in poor compatibility. Continuous printing on flexible substrates requires precise tension control; otherwise, misalignment can easily occur. Improper temperature or time control during post-processing can lead to film cracking and decreased conductivity. Moreover, the pattern resolution is generally >20μm, greatly hindering the high-density integration application of conductive polymers.

[0004] While photolithography can achieve high-resolution patterns, it is prone to material damage. During development and resist removal, chemical reagents may corrode the molecular structure of conductive polymer films, reducing their electrochemical performance and affecting device stability. Furthermore, the substrate compatibility is narrow, and exposure and post-processing (such as high-temperature baking and plasma etching) require high tolerance to flexible substrates (such as polyethylene terephthalate (PET), easily leading to substrate deformation, aging, or even damage, making it unsuitable for flexible device fabrication. Moreover, the electrochemical activity of conductive polymers is easily affected by photolithography solvents, making their patterning process often incompatible with the photolithography process. It is difficult to achieve high-performance conductive polymer patterning using photolithography, which is detrimental to large-scale industrial production. For large-area array fabrication of transistor devices, its efficiency is low, making it difficult to meet high-volume production demands.

[0005] In the existing technology, although there are patents (such as CN202310320395.2) that mention related patterning technology, the core contradiction of insufficient resolution of printing method and material damage and poor compatibility of photolithography method has not been resolved. There is an urgent need for a patterning preparation technology that takes into account high resolution, high electrochemical activity and flexible adaptability. Summary of the Invention

[0006] To address the problems of low pattern resolution, easy material damage, and poor electrochemical activity in the preparation of conductive polymer films using traditional printing and photolithography methods, this invention provides an electrochemical preparation method, transfer method, and application of patterned conductive polymer films. Utilizing photolithographic patterning of conductive substrates, in-situ electrochemical deposition, and template transfer techniques, this invention achieves the preparation of high-resolution, high-electrochemical-activity patterned conductive polymer films and their integration with flexible substrates. The process is simple, highly controllable, and suitable for large-scale production. It provides high-quality material support for high-precision devices such as flexible organic electrochemical transistors and gas sensors, and has broad application prospects.

[0007] To achieve the above objectives, in a first aspect, the present invention provides an electrochemical preparation method for patterned conductive polymer films, the electrochemical preparation method comprising: S1. The conductive substrate is sequentially subjected to a first wash, a first dry, and an ultraviolet ozone pretreatment. S2. Perform photolithographic patterning on the conductive substrate pretreated in S1. S3. The conductive substrate that has been photolithographically patterned in S2 is placed in an electropolymer solution for in-situ electrochemical deposition to form a patterned conductive polymer film. S4. Perform a second washing, adhesive removal, and second drying on the patterned conductive polymer film.

[0008] Preferably, in step S1, the conductive substrate is selected from one or more of fluorine-doped tin oxide conductive glass, indium tin oxide conductive glass, conductive polymer substrate, and metal foil substrate.

[0009] Preferably, in step S1, the conditions for the first washing include: ultrasonically cleaning the conductive substrate in ammonia, ethanol and acetone in sequence for 5 to 15 minutes, preferably 8 to 10 minutes.

[0010] Preferably, the mass fraction of the ammonia water is 5-15%, more preferably 8-12%.

[0011] Preferably, in step S1, the first drying method is to use nitrogen gas to dry, with nitrogen purity ≥99.99%, gas flow pressure 0.1~0.3MPa, and purging time 30~120s.

[0012] Preferably, in step S1, the conditions for ultraviolet ozone pretreatment include: treating with an ultraviolet ozone device capable of releasing ozone for 10-20 minutes.

[0013] Preferably, the ozone concentration is 0.1~0.5 mg / m³. 3 .

[0014] Preferably, in step S2, the specific process of photolithographic patterning is as follows: spin-coating photoresist onto the surface of the conductive substrate after pretreatment in S1, followed by pre-baking, ultraviolet exposure, and development to obtain a selectively exposed conductive substrate.

[0015] Preferably, the photoresist is selected from one or more of AZ5214 photoresist, SU-8 photoresist and AZ4620 photoresist.

[0016] Preferably, the pre-baking conditions include: a temperature of 95~105℃ and a time of 30~90s.

[0017] Preferably, the conditions for ultraviolet exposure include: irradiation with ultraviolet light of wavelength 365nm for 10~30s.

[0018] Preferably, the developing conditions include: immersing in developing solution for 30 to 90 seconds at a temperature of 15 to 35°C.

[0019] Preferably, the developer is one or more of RZX-3038 developer, AZ 400K developer, and MF-319 developer.

[0020] Preferably, in step S3, the electropolymerization polymer solution is prepared by dissolving polymer monomers and surfactants in water at a molar ratio of 1:0.5~1.5.

[0021] Preferably, the polymer monomer is selected from one or more of pyrrole, thiophene, and aniline.

[0022] Preferably, the surfactant is selected from one or more of sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide, and Tween-80.

[0023] Preferably, the conditions for the in-situ electrochemical deposition include: a two-electrode system, with Ag / AgCl as the reference electrode, the photolithographically patterned conductive substrate as the working electrode, an electrode spacing of 1-2 cm, a deposition voltage of 0.5-1.1 V, a deposition time of 1-5 min, and a current density of 0.5-2 A / cm². 2 .

[0024] Preferably, in step S4, the second washing involves rinsing with ultrapure water 3 to 5 times.

[0025] Preferably, the conditions for removing the adhesive include: immersing the patterned conductive polymer film in anhydrous ethanol for 1-3 minutes, and then rinsing it with ultrapure water 3-5 times.

[0026] Preferably, the second drying method is to use nitrogen gas to dry, and then dry at a temperature of 80~100℃ for 3~7 minutes.

[0027] Secondly, the present invention provides a method for transferring patterned conductive polymer films, the method comprising: (1) Take the patterned conductive polymer film prepared by the preparation method of the present invention and fix it on a flat worktable; (2) Select a transfer template, place the patterned surface of the transfer template downwards, at a 45° angle to the patterned conductive polymer film, and contact the edge of the patterned conductive polymer film; (3) Apply uniform pressure from one side of the transfer template to the other side to eliminate air bubbles between the transfer template and the patterned conductive polymer film, so that the two are completely bonded together; (4) Peel off the transfer template at a 45° angle, and the patterned conductive polymer film is completely transferred from the original conductive substrate to the transfer template to complete the transfer.

[0028] Preferably, in step (2), the transfer template is selected from one or more of polydimethylsiloxane film, silicon-based template, metal template and polymer rigid template.

[0029] Preferably, in step (3), the method of applying uniform pressure is roller compaction.

[0030] Preferably, the roller is selected from one of a glass rod, a polytetrafluoroethylene roller, and a rubber roller.

[0031] Preferably, the applied pressure is 0.1~0.5 MPa.

[0032] Preferably, in step (4), the peeling further includes: adding 0.1~0.5 mL of deionized water to the edges of both to assist in the peeling.

[0033] Thirdly, the present invention provides an application of the patterned conductive polymer film prepared by the preparation method described in the present invention in the preparation of flexible organic electrochemical transistor devices.

[0034] In the above technical solution, the electrochemical preparation method for patterned conductive polymer thin films of the present invention achieves precise preparation of high-precision patterns by combining photolithographic patterning with in-situ electrochemical deposition. The patterns have high resolution and retain the electrochemical activity of the conductive polymer. The process parameters are clearly defined and controllable, the operation is simple, and the repeatability is good, making it suitable for large-scale production.

[0035] The transfer method of the present invention adopts a 45° angle bonding and peeling method, combined with a uniform pressure bubble removal process, which effectively avoids problems such as pattern damage and bubble residue during the transfer process, resulting in a high transfer success rate and complete preservation of the pattern's accuracy and integrity.

[0036] The patterned conductive polymer film prepared by this invention has good conductivity, electrochemical activity and flexibility. When applied to the preparation of flexible organic electrochemical transistor devices, it can significantly improve the performance stability and reliability of the devices and has broad application prospects.

[0037] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0038] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings: Figure 1 A schematic diagram of the electrochemical preparation of patterned polypyrrole conductive polymer films using a constant voltage current source two-electrode system, and a flowchart of the in-situ electrochemical growth process of conductive polymer patterning using a patterned conductive substrate template. Figure 2 Patterned polypyrrole conductive polymer films are generated on the selectively exposed FTO conductive glass surface for patterning. Figure 3 The growth curve and redox curve of the patterned polypyrrole conductive polymer film prepared by electrochemical method in Example 1 of this invention are shown. Figure 4 This is a SEM image of the polypyrrole conductive polymer film prepared in Example 1 of the present invention. Figure 5 The pattern is shown in Example 1 of this invention, which is a pattern of a patterned polypyrrole conductive polymer film. Figure 6 Microscopic patterns of patterned polypyrrole conductive polymer films on PDMS transfer templates; Figure 7 Macroscopic photograph of a polypyrrole conductive polymer film on a PDMS transfer template; Figure 8 This is a flowchart of the transfer process of the present invention; Figure 9Image a is an enlarged view of the patterned polypyrrole conductive polymer film formed on the patterned selectively exposed FTO conductive glass surface in Comparative Example 1; image b is an enlarged view of the patterned polypyrrole conductive polymer film formed on the patterned selectively exposed FTO conductive glass surface in Comparative Example 2; image c is an enlarged view of the patterned polypyrrole conductive polymer film formed on the patterned selectively exposed FTO conductive glass surface in Example 1. Detailed Implementation

[0039] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0040] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0041] In a first aspect, the present invention provides an electrochemical preparation method for patterned conductive polymer films, the electrochemical preparation method comprising: S1. The conductive substrate is sequentially subjected to a first wash, a first dry, and an ultraviolet ozone pretreatment. S2. Perform photolithographic patterning on the conductive substrate pretreated in S1. S3. The conductive substrate that has been photolithographically patterned in S2 is placed in an electropolymer solution for in-situ electrochemical deposition to form a patterned conductive polymer film. S4. Perform a second washing, adhesive removal, and second drying on the patterned conductive polymer film.

[0042] The electrochemical preparation method for patterned conductive polymer thin films of the present invention achieves precise preparation of high-precision patterns by combining photolithographic patterning with in-situ electrochemical deposition. The patterns have high resolution and retain the electrochemical activity of the conductive polymer. The process parameters are clearly defined and controllable, the operation is simple, and the repeatability is good, making it suitable for large-scale production.

[0043] In this invention, the conductive substrate must possess high conductivity, good chemical stability, and surface smoothness to provide stable conductive sites for in-situ electrochemical deposition; it must also have good compatibility with photoresist and electropolymerization solutions, and will not undergo chemical reactions that affect pattern accuracy. Therefore, in step S1, the conductive substrate is selected from one or more of fluorine-doped tin oxide conductive glass, indium tin oxide conductive glass, conductive polymer substrate, and metal foil substrate. The conductive polymer substrate and metal foil substrate are suitable for flexible device requirements. The flexible properties of the metal foil substrate and the lightweight properties of the conductive polymer substrate can meet the device integration needs in different scenarios, avoiding the application limitations of traditional rigid substrates.

[0044] In this invention, in step S1, the conditions for the first washing include: placing the conductive substrate in ammonia, ethanol and acetone in sequence for ultrasonic cleaning for 5 to 15 minutes, preferably 8 to 10 minutes, which can ensure the cleaning effect and avoid scratches on the substrate surface caused by prolonged ultrasonic cleaning.

[0045] In this invention, the mass fraction of the ammonia water is 5-15%, preferably 8-12%. This concentration range can effectively remove oil and oxides from the substrate surface without corroding the substrate.

[0046] In this invention, in step S1, the first drying method is to use nitrogen gas to dry the substrate. The nitrogen gas purity is ≥99.99%. High-purity nitrogen gas can avoid oxidation of the substrate surface caused by oxygen and moisture. The airflow pressure is 0.1~0.3MPa and the blowing time is 30~120s. The low-pressure airflow can quickly dry the moisture without impacting the substrate surface and preventing residual water stains from affecting the adhesion of photoresist.

[0047] In this invention, in order to effectively improve the hydrophilicity of the conductive substrate surface, active hydroxyl groups are introduced to enhance the adhesion between the photoresist and the conductive substrate; at the same time, residual organic matter can be removed to avoid affecting the electrochemical deposition effect. In step S1, the conditions for the ultraviolet ozone pretreatment include: treating with an ultraviolet ozone device that can release ozone for 10 to 20 minutes. If the treatment time is too long, the conductivity of the substrate may decrease.

[0048] In this invention, the ozone concentration is 0.1~0.5 mg / m³. 3 .

[0049] In this invention, the specific process of photolithographic patterning in step S2 is as follows: spin-coating photoresist onto the surface of the conductive substrate after pretreatment in S1, followed by pre-baking, ultraviolet exposure, and development to obtain a selectively exposed conductive substrate.

[0050] In this invention, the photoresist is selected from one or more of AZ5214 photoresist, SU-8 photoresist and AZ4620 photoresist.

[0051] In this invention, in order to ensure that the solvent in the photoresist is fully removed and to strengthen the adhesion between the photoresist layer and the substrate, the pre-baking conditions include: a temperature of 95~105℃ and a time of 30~90s. This ensures that the photoresist is not carbonized and that solvent residue can prevent incomplete development.

[0052] In this invention, the ultraviolet exposure conditions include: irradiating the photoresist molecules with ultraviolet light of wavelength 365nm for 10~30s to induce cross-linking and curing, ensuring sufficient cross-linking and avoiding pattern blurring caused by insufficient exposure.

[0053] In this invention, to ensure a stable development rate, the development conditions include: immersing in a developing solution for 30 to 90 seconds at a temperature of 15 to 35°C.

[0054] In this invention, in order to accurately remove photoresist from unexposed areas without corroding the conductive substrate or affecting its conductivity, the developer is one or more of RZX-3038 developer, AZ 400K developer, and MF-319 developer.

[0055] In this invention, in step S3, the electropolymerization polymer solution is prepared by dissolving polymer monomers and surfactants in water at a molar ratio of 1:0.5~1.5.

[0056] In this invention, the polymer monomers must have good electrochemical polymerization activity and can undergo oxidative polymerization at low voltage. For example, they can be selected from one or more of pyrrole, thiophene and aniline. These monomers have low toxicity, are easy to obtain, and are suitable for large-scale preparation.

[0057] In this invention, the surfactant can improve the solubility of monomers in ultrapure water and avoid uneven film formation caused by monomer aggregation. For example, it can be selected from one or more of sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide and Tween-80.

[0058] In this invention, the conditions for the in-situ electrochemical deposition include: a two-electrode system, with Ag / AgCl as the reference electrode, the photolithographically patterned conductive substrate as the working electrode, an electrode spacing of 1-2 cm, a deposition voltage of 0.5-1.1 V, a deposition time of 1-5 min, and a current density of 0.5-2 A / cm². 2 The two-electrode system has a simple structure and is easy to operate, making it suitable for mass production. The deposition time and voltage can be used to control the film thickness, enabling precise control from micron to submicron thickness to meet the channel layer requirements of different devices.

[0059] In this invention, in step S4, the second washing involves rinsing with ultrapure water 3 to 5 times.

[0060] In this invention, the conditions for removing the photoresist include: immersing the patterned conductive polymer film in anhydrous ethanol for 1-3 minutes, and then rinsing it with ultrapure water 3-5 times. Anhydrous ethanol can quickly dissolve the photoresist without damaging the grown conductive polymer film. The immersion time is based on the standard of completely removing the photoresist without any residue, so as to avoid residual photoresist affecting the subsequent transfer process.

[0061] In this invention, the second drying method is to use nitrogen to blow dry, and then dry at a temperature of 80~100℃ for 3~7 minutes, for example, drying at a temperature of 85℃ for 5 minutes; drying at a temperature of 90℃ for 4 minutes; drying at a temperature of 95℃ for 6 minutes; drying at a temperature of 98℃ for 6 minutes or drying at a temperature of 99℃ for 7 minutes.

[0062] Secondly, the present invention provides a method for transferring patterned conductive polymer films, the method comprising: (1) Take the patterned conductive polymer film prepared by the preparation method of the present invention and fix it on a flat worktable; (2) Select a transfer template, place the patterned surface of the transfer template downwards, at a 45° angle to the patterned conductive polymer film, and contact the edge of the patterned conductive polymer film; (3) Apply uniform pressure from one side of the transfer template to the other side to eliminate air bubbles between the transfer template and the patterned conductive polymer film, so that the two are completely bonded together; (4) Peel off the transfer template at a 45° angle, and the patterned conductive polymer film is completely transferred from the original conductive substrate to the transfer template to complete the transfer.

[0063] The transfer method of the present invention adopts a 45° angle bonding and peeling method, combined with a uniform pressure bubble removal process, which effectively avoids problems such as pattern damage and bubble residue during the transfer process, resulting in a high transfer success rate and complete preservation of the pattern's accuracy and integrity.

[0064] In this invention, in step (2), the transfer template is selected from one or more of polydimethylsiloxane film, silicon-based template, metal template and polymer rigid template. These transfer templates have moderate adhesion and the adhesion force to the conductive polymer film is greater than the adsorption force between the film and the original substrate, which can achieve low-damage peeling; and they have good flexibility and can adapt to the complete transfer of micro and nanoscale patterns.

[0065] In this invention, in step (3), the method of applying uniform pressure is roller compaction.

[0066] In this invention, the roller is selected from one of a glass rod, a polytetrafluoroethylene roller, and a rubber roller.

[0067] In this invention, the applied pressure is 0.1~0.5 MPa, for example, it can be 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa or 0.5 MPa, etc.

[0068] In this invention, step (4) further includes: adding 0.1 to 0.5 mL of deionized water to the edges of the two objects to assist in the peeling process, such as adding 0.1 mL, 0.2 mL, 0.3 mL, 0.4 mL, 0.45 mL, or 0.5 mL.

[0069] Thirdly, the present invention provides an application of the patterned conductive polymer film prepared by the preparation method described in the present invention in the preparation of flexible organic electrochemical transistor devices.

[0070] The patterned conductive polymer film prepared by this invention has good conductivity, electrochemical activity and flexibility. When applied to the preparation of flexible organic electrochemical transistor devices, it can significantly improve the performance stability and reliability of the devices and has broad application prospects.

[0071] In this invention, the room temperature is 15-30°C.

[0072] The present invention will be described in detail below through examples. In the following examples, the pharmaceuticals and agents are all conventional commercially available products.

[0073] Example 1 S1. Conductive Substrate Pretreatment: Fluorine-doped tin oxide (FTO) conductive glass was selected as the conductive substrate and ultrasonically cleaned for 9 minutes each in 10% ammonia, ethanol, and acetone solutions. Subsequently, it was purged with 99.99% pure nitrogen gas at a pressure of 0.2 MPa for 60 seconds to complete the first drying step. The dried conductive substrate was then placed in an ultraviolet ozone generator at an ozone concentration of 0.1 mg / m³. 3 Under these conditions, the UV ozone pretreatment was completed after 15 minutes of treatment.

[0074] S2. Photolithographic patterning: AZ5214 photoresist is spin-coated onto the surface of the pretreated conductive substrate, followed by pre-baking at 100℃ for 60s; through pattern design, the pre-baked conductive substrate is placed in a maskless photolithography machine and exposed to ultraviolet light at a wavelength of 365nm for 60s; at 25℃, the exposed substrate is immersed in RZX-3038 developer for 60s; the developed substrate is rinsed twice with ultrapure water to obtain a selectively exposed conductive substrate.

[0075] S3. In-situ electrochemical deposition: Weigh pyrrole monomer and sodium dodecylbenzenesulfonate in a molar ratio of 1:1 and dissolve them in ultrapure water to prepare an electropolymerization polymer solution; use as follows... Figure 1The two-electrode system shown uses Ag / AgCl as the reference electrode and a photolithographically patterned conductive substrate as the working electrode. A constant voltage current source is activated at a deposition voltage of 0.8V and a current density of 1.2A / cm². 2 Under the conditions of deposition for 3 minutes, a black / dark brown polypyrrole (PPy) conductive polymer film with a specific pattern gradually appears on the surface of the working electrode, namely the patterned conductive polymer film, such as... Figure 2 As shown, the obtained patterned conductive polymer film has a pentagonal array pattern; as Figure 9 As shown in Figure c, the PPy conductive polymer film grows uniformly, with clear boundaries and moderate thickness.

[0076] S4. Post-processing: Rinse the patterned conductive polymer film four times with ultrapure water, then soak it in ethanol for 2 minutes to remove the adhesive; first blow it dry with nitrogen, then heat it at 90℃ for 5 minutes to complete the second drying, and obtain the dried patterned conductive polymer film.

[0077] S5. Transfer process: Fix the dried patterned conductive polymer film obtained above on a flat workbench. Select a polydimethylsiloxane (PDMS) film as a transfer template. Place the template with the patterned side facing down and make contact with the edge of the film at a 45° angle. Use a glass rod as a roller and apply pressure from one side of the template to the other at a pressure of 0.3 MPa to remove air bubbles. Add 0.3 mL of deionized water to the edge of the template and the film, and slowly peel off the template at a 45° angle to complete the transfer and obtain an applicable patterned conductive polymer film.

[0078] Example 2 The method described in Example 1 was implemented, except that in the in-situ electrochemical deposition of step S3, the phrase "weighing pyrrole monomer and sodium dodecylbenzene sulfonate in a molar ratio of 1:1 and dissolving them in ultrapure water to prepare an electropolymerization polymer solution" was replaced with "weighing 3,4-ethylenedioxythiophene (EDOT) monomer and sodium poly(p-styrene sulfonate) (NaPSS) in a molar ratio of 1:10 and dissolving them in ultrapure water to prepare an electropolymerization polymer solution"; and the phrase "at a deposition voltage of 0.8V and a current density of 1.2A / cm²" was replaced with "preparing an electropolymerization polymer solution at a deposition voltage of 0.8V and a current density of 1.2A / cm²". 2 Replace "deposited for 3 minutes under the conditions of deposition voltage 1.1V and current density 2.0A / cm²" with "deposited at a voltage of 1.1V and a current density of 2.0A / cm²". 2 "Deposit for 1.5 min under the condition of [condition]", with other steps unchanged, a brownish-blue PEDOT:PSS conductive polymer film with a specific pattern gradually appears on the surface of the working electrode, namely the patterned conductive polymer film. After post-processing and transfer, an applicable patterned conductive polymer film is finally obtained.

[0079] Example 3 The method described in Example 1 was implemented, except that in the in-situ electrochemical deposition of step S3, the phrase "weighing pyrrole monomer and sodium dodecylbenzenesulfonate in a molar ratio of 1:1 and dissolving them in ultrapure water to prepare an electropolymerization polymer solution" was replaced with "weighing N,N-dimethylacetamide (DMA) monomer and sulfuric acid (H2SO4) in a molar ratio of 2:25 and dissolving them in ultrapure water to prepare an electropolymerization polymer solution"; and the phrase "at a deposition voltage of 0.8V and a current density of 1.2A / cm²" was replaced with "...". 2 Replace "deposited for 3 minutes under the conditions of deposition voltage 1.1V and current density 1.8A / cm²" with "deposited at a voltage of 1.1V and a current density of 1.8A / cm²". 2 Under the condition of deposition for 3 min", with other steps unchanged, a reversible color-changing poly(2,5-dimethoxyaniline) (PDMA) conductive polymer film with a specific pattern of yellow-green-blue gradually appears on the surface of the working electrode, namely the patterned conductive polymer film. After post-processing and transfer, the finally applicable patterned conductive polymer film is obtained.

[0080] Comparative Example 1 The method described in Example 1 was carried out, except that "at a deposition voltage of 0.8V and a current density of 1.2A / cm²", the deposition was carried out at a deposition voltage of 0.8V and a current density of 1.2A / cm². 2 Replace "deposited for 3 minutes under the conditions of deposition voltage 0.8V and current density 1.2A / cm³" with "deposited at a voltage of 0.8V and a current density of 1.2A / cm³". 2 Deposition under the conditions of 30s yielded a film with the following properties: Figure 9 As shown in a.

[0081] Depend on Figure 9 As can be seen from content a, when the deposition time is too short, the PPy conductive polymer film grows unevenly and discontinuously, making it impossible to carry out subsequent transfer steps, and the electrochemical activity is poor, affecting the further application of the conductive polymer film.

[0082] Comparative Example 2 The method described in Example 1 was carried out, except that "at a deposition voltage of 0.8V and a current density of 1.2A / cm²", the deposition was carried out at a deposition voltage of 0.8V and a current density of 1.2A / cm². 2 Replace "deposited for 3 minutes under the specified conditions" with "deposit voltage 0.8V, current density 1.2A / cm³". 2 "Deposit for 10 min under the conditions", and the resulting film properties are as follows Figure 9 As shown in b.

[0083] Depend on Figure 9 As can be seen from b, when the deposition time is too long, the PPy conductive polymer film grows too thick, which is not conducive to subsequent transfer and cannot be further applied.

[0084] Detection Example 1 The growth curve and redox curve of the polypyrrole conductive polymer film in Example 1 were detected and recorded, and the results are as follows: Figure 3 As shown.

[0085] The growth curve of conductive polymer thin films can describe the changes in film thickness, deposition rate, and deposition saturation time over time, and is primarily used to characterize the synthesis and deposition kinetics of the thin films.

[0086] Redox curves: Redox curves directly reflect the electrochemical activity of the channel material. The logic is achieved by corresponding the three core parameters—peak potential, peak current, and peak shape symmetry—to the doping / dedoping capability, carrier concentration, and reaction reversibility of the channel material.

[0087] The growth curve determines the baseline of the redox curve: the more uniform the growth of the conductive polymer film and the more controllable its thickness, the better the symmetry of the redox peaks and the more significant the linear relationship between the peak current and the thickness.

[0088] Redox curves provide feedback on growth quality: If the redox peak shape is distorted or the peak potential difference is too large, it indicates that there are defects in the film growth process (such as agglomeration or high porosity), and the deposition potential or time needs to be adjusted.

[0089] Depend on Figure 3 As can be seen from the content, the redox curve of the polypyrrole conductive polymer film of Example 1 of the present invention exhibits good redox peak symmetry and minimal distortion, indicating that the polypyrrole conductive polymer film of Example 1 is uniformly grown, of moderate thickness, and possesses excellent electrochemical activity. Furthermore, after multiple cyclic voltammetry tests, the peak potential of the polypyrrole conductive polymer film prepared in Example 1 of the present invention shows almost no decrease, indicating good chemical stability.

[0090] Detection Example 2 Microscopic observation of the polypyrrole conductive polymer film in Example 1 yielded the following results: Figure 5-7 As shown.

[0091] Depend on Figure 5-7 It is known that the pattern resolution of the polypyrrole conductive polymer film in Example 1 of the present invention can reach ≤5μm, which is more than 4 times higher than the film resolution. The template for growth is obtained by photolithography, the resolution of photolithography is ≤5μm, the resolution of the grown polypyrrole conductive polymer film is ≤5μm, and the resolution of the patterned conductive polymer film after transfer is ≤5μm.

[0092] Detection Example 3 The polypyrrole conductive polymer film of Example 1 was subjected to SEM analysis, and the results are as follows: Figure 4 As shown.

[0093] Depend on Figure 4As can be seen from the SEM image, the surface of the polypyrrole conductive polymer film prepared in Example 1 of the present invention is dense and uniform, which provides a good premise for subsequent applications.

[0094] In summary, the electrochemical preparation method for patterned conductive polymer films of this invention fundamentally avoids the limitations of existing technologies. Through electropolymerization, conductive polymer chains are directly nucleated and grown on the surface of a conductive substrate, eliminating the need for organic solvents and developing solutions, and fully preserving the conjugated structure and electrochemical active sites. While printing and photolithography are traditional mainstream technologies in the patterning preparation of conductive polymers, they are generally limited by their process principles and suffer from the critical problem of damage to the intrinsic properties of the material, directly restricting the electrochemical activity of devices and the expansion of application scenarios. In-situ growth technology can specifically address this pain point.

[0095] Simultaneously, this invention achieves a perfect balance between controllable photolithography for high-precision patterning and efficient fabrication, avoiding damage to the materials caused by either method. Adjusting electrochemical parameters allows for precise control of the growth shape of conductive polymers, such as polypyrrole conductive polymer films, ensuring uniformity and density. Compared to traditional liquid-phase or vapor-phase deposition methods, this invention offers a simpler and more efficient process, suitable for large-scale fabrication, and provides a new technological pathway for high-performance flexible electronic devices.

[0096] Furthermore, the electrochemical method of this invention can precisely control the thickness of the polypyrrole conductive polymer film by adjusting parameters such as current, voltage, and reaction time. This alters the channel length, allowing it to be scaled down to the micro-nano level, reducing carrier transport paths, increasing current density, and achieving rapid switching performance, making it suitable for applications in vertical-structure organic electrochemical transistors.

[0097] Furthermore, compared to polypyrrole conductive polymer films prepared by traditional methods, films obtained by electrochemical deposition have a more uniform thickness distribution and can be arbitrarily designed with growth patterns, which can reduce material inhomogeneity and improve device stability and performance.

[0098] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0099] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0100] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. An electrochemical preparation method for patterned conductive polymer films, characterized in that, The electrochemical preparation method includes: S1. The conductive substrate is sequentially subjected to a first wash, a first dry, and an ultraviolet ozone pretreatment. S2. Perform photolithographic patterning on the conductive substrate pretreated in S1. S3. The conductive substrate that has been photolithographically patterned in S2 is placed in an electropolymer solution for in-situ electrochemical deposition to form a patterned conductive polymer film. S4. Perform a second washing, adhesive removal, and second drying on the patterned conductive polymer film.

2. The preparation method according to claim 1, characterized in that, In step S1, the conductive substrate is selected from one or more of fluorine-doped tin oxide conductive glass, indium tin oxide conductive glass, conductive polymer substrate, and metal foil substrate; The conditions for the first washing include: ultrasonically cleaning the conductive substrate in ammonia, ethanol and acetone in sequence for 5 to 15 minutes, preferably 8 to 10 minutes; Preferably, the mass fraction of the ammonia water is 5-15%, more preferably 8-12%; The first drying method is to use nitrogen gas to dry, with nitrogen purity ≥99.99%, gas flow pressure 0.1~0.3MPa, and purging time 30~120s; The conditions for the ultraviolet ozone pretreatment include: treating with an ultraviolet ozone device capable of releasing ozone for 10-20 minutes; Preferably, the ozone concentration is 0.1~0.5 mg / m³. 3 .

3. The preparation method according to claim 1 or 2, characterized in that, In step S2, the specific process of photolithographic patterning is as follows: spin-coating photoresist onto the surface of the conductive substrate after pretreatment in S1, followed by pre-baking, ultraviolet exposure, and development to obtain a selectively exposed conductive substrate. Preferably, the photoresist is selected from one or more of AZ5214 photoresist, S1805 photoresist, SU-8 photoresist and AZ4620 photoresist; The pre-baking conditions include: a temperature of 95~105℃ and a time of 30~90s; The conditions for the ultraviolet exposure include: irradiation with ultraviolet light of wavelength 365nm for 10~30s; The developing conditions include: immersing in developing solution for 30 to 90 seconds at a temperature of 15 to 35°C; Preferably, the developer is one or more of RZX-3038 developer, AZ 400K developer, and MF-319 developer.

4. The preparation method according to any one of claims 1-3, characterized in that, In step S3, the electropolymerization polymer solution is prepared by dissolving polymer monomers and surfactants in water at a molar ratio of 1:0.5~1.5; The polymer monomer is selected from one or more of pyrrole, thiophene, and aniline; The surfactant is selected from one or more of sodium dodecylbenzenesulfonate, hexadecyltrimethylammonium bromide and Tween-80; The conditions for the in-situ electrochemical deposition include: a two-electrode system with Ag / AgCl as the reference electrode, the photolithographically patterned conductive substrate as the working electrode, an electrode spacing of 1–2 cm, a deposition voltage of 0.5–1.1 V, a deposition time of 1–5 min, and a current density of 0.5–2 A / cm². 2 .

5. The preparation method according to any one of claims 1-4, characterized in that, In step S4, the second washing involves rinsing with ultrapure water 3 to 5 times; The conditions for removing the adhesive include: immersing the patterned conductive polymer film in anhydrous ethanol for 1-3 minutes, and then rinsing it with ultrapure water 3-5 times. The second drying method is to use nitrogen gas to dry the product, and then dry it at a temperature of 80~100℃ for 3~7 minutes.

6. A method for transferring patterned conductive polymer films, characterized in that, The transfer method includes: (1) Take the patterned conductive polymer film prepared by any one of claims 1-5 and fix it on a flat worktable; (2) Select a transfer template, place the patterned surface of the transfer template downwards, at a 45° angle to the patterned conductive polymer film, and contact the edge of the patterned conductive polymer film; (3) Apply uniform pressure from one side of the transfer template to the other side to eliminate air bubbles between the transfer template and the patterned conductive polymer film, so that the two are completely bonded together; (4) Peel off the transfer template at a 45° angle, and the patterned conductive polymer film is completely transferred from the original conductive substrate to the transfer template to complete the transfer.

7. The transfer method according to claim 6, characterized in that, In step (2), the transfer template is selected from one or more of polydimethylsiloxane film, silicon-based template, metal template and polymer rigid template.

8. The transfer method according to claim 6 or 7, characterized in that, In step (3), the method of applying uniform pressure is roller compaction; The roller is selected from one of glass rod, polytetrafluoroethylene roller and rubber roller; The applied pressure is 0.1~0.5 MPa.

9. The transfer method according to any one of claims 6-8, characterized in that, In step (4), the peeling also includes adding 0.1 to 0.5 mL of deionized water to the edges of both to assist in the peeling.

10. The application of a patterned conductive polymer film prepared by any one of claims 1-5 in the preparation of flexible organic electrochemical transistor devices.

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