Vertical fiber-based organic electrochemical transistors and methods of making the same

Abstract

The application provides a vertical fiber-based organic electrochemical transistor and a preparation method thereof. The transistor comprises a conductive fiber, a first conductive layer as a source electrode is arranged on one end surface of the conductive fiber, an insulating layer is arranged on the surface of the conductive fiber, and the insulating layer is coaxially arranged with the conductive fiber; a second conductive layer as a drain electrode is arranged on the surface of the insulating layer, a source layer as a channel is arranged between the drain electrode and the source electrode; the transistor further comprises a second conductive fiber as a gate electrode, and a gel electrolyte is arranged between the gate electrode and the source electrode and the drain electrode. The vertical transistor structure is prepared, the thickness of the insulating layer is controlled to realize the adjustment of the channel length, the short channel effect is reduced while the short channel is beneficial to the transmission and migration of electrons, and compared with a traditional fiber-based transistor, the vertical fiber-based organic electrochemical transistor has reduced traps caused by the structure, the performance of the transistor is improved, and the transistor can be widely applied to the fields of intelligent wearable and biosensors.

Description

Technical Field

[0001] This invention relates to the field of organic electrochemical transistor technology, and more particularly to a vertical fiber-based organic electrochemical transistor and its fabrication method. Background Technology

[0002] In recent years, many researchers have focused on studying fiber-based organic electrochemical transistors (OLEDs), which can be applied to logic circuits, artificial synapses, and other fields. One of the most important parameters for evaluating the performance of OLEDs is transconductance; a higher transconductance value means a greater amplification of the input signal. Improving transconductance has become a key research focus. It has been reported that for depletion-type OLEDs, channel structure and related parameters are the main factors limiting transconductance. An invention patent (application number 201911245752.3) discloses a vertically structured OLED and its fabrication method. This method uses a spin-coating process to deposit an active layer thin film followed by annealing to obtain the active layer, with the active layer thickness, i.e., the channel length, controlled between 100 and 600 nm. Although this method shortens the channel length of the transistor, the substrate is made of glass or resin materials that can be annealed, a process unsuitable for fiber-based transistor fabrication. Furthermore, the overall fabrication process is complex and difficult to achieve industrial-scale mass production.

[0003] Currently, there are reports on improving the performance of organic electrochemical transistors (OETTs) by increasing the channel width. However, for fiber-based OETTs, the fiber diameter is fixed. Other methods have attempted to improve performance by increasing the channel thickness, but this reduces the response speed, hindering future applications. Due to the limitations of the fabrication process, controlling the channel size of fiber-based OETTs is difficult. Therefore, reducing the channel size of fiber-based OETTs is of paramount importance.

[0004] An invention patent (application number 201911375393.3) discloses a fiber-shaped vertical-channel transistor and its fabrication method. The semiconductor layer of this transistor is vertically disposed on the transistor surface with a thickness of 100-140 nm, and its carrier transport channel length (channel length) is equal to the thickness of the semiconductor layer, thus achieving the goal of shortening the channel size. However, shortening the channel size often easily leads to short-channel effects and trap effects, causing degradation in transistor performance and reliability, thereby limiting the transistor's lifespan and application areas. Currently, there is no existing technology that can simultaneously control the channel size parameters of a fiber-based organic electrochemical transistor while effectively mitigating short-channel effects, reducing traps, and ensuring transistor performance.

[0005] In view of this, it is necessary to design an improved vertical fiber-based organic electrochemical transistor and its fabrication method to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a vertical fiber-based organic electrochemical transistor and its fabrication method. Using conductive fibers as the substrate, a vertical transistor structure is fabricated, and the channel size is controlled by controlling the thickness of the insulating layer, which is beneficial to electron transport and migration, while avoiding the occurrence of short-channel effects. Compared with traditional fiber-based transistors, it reduces structural traps and improves the performance of fiber-based organic electrochemical transistors.

[0007] To achieve the above-mentioned objectives, the present invention provides a vertical fiber-based organic electrochemical transistor, comprising a conductive fiber, wherein a first conductive layer is provided on one end surface of the conductive fiber as a source electrode, an insulating layer is provided on the cylindrical surface of the conductive fiber, and the insulating layer is coaxially disposed with the conductive fiber; a second conductive layer is provided on the surface of the insulating layer as a drain electrode, and a source layer is provided between the drain electrode and the source electrode as a channel; the transistor further comprises a second conductive fiber as a gate electrode, and a gel electrolyte is provided between the gate electrode and the source electrode and the drain electrode.

[0008] As a further improvement of the present invention, the first conductive layer serving as the source and the second conductive layer serving as the drain are coaxially disposed; the thickness of the insulating layer is greater than 10 nm, and the thickness of the insulating layer is the vertical distance between the drain and the source, which is the length of the channel.

[0009] As a further improvement of the present invention, the second conductive layer, the insulating layer, and the conductive fiber are all coaxially arranged.

[0010] As a further improvement of the present invention, the active layer is a mixture of PEDOT:PSS and graphene oxide, wherein the volume ratio of PEDOT:PSS to graphene oxide is (0.5~2):1.

[0011] As a further improvement of the present invention, the concentration of PEDOT:PSS is 1wt%~2wt%; and the concentration of graphene oxide is 0.1wt%~0.5wt%.

[0012] As a further improvement of the present invention, the conductive fiber includes one of carbon fiber, composite conductive fiber or flexible conductive fiber.

[0013] As a further improvement of the present invention, the gel electrolyte comprises several or all of polyvinyl alcohol, sodium poly(p-styrene sulfonate), ethylene glycol, sorbitol, and deionized water.

[0014] As a further improvement of the present invention, the insulating layer includes one or more of silicone rubber, insulating varnish or transparent adhesive.

[0015] As a further improvement of the present invention, the first conductive layer and the second conductive layer include one of silver paste, copper particles, platinum, silver nanowires, and conductive tape.

[0016] This invention also provides a method for fabricating a vertical fiber-based organic electrochemical transistor, comprising the following steps:

[0017] S1. Perform surface cleaning treatment on the conductive fibers and dry them for later use;

[0018] S2. Coat one end of the conductive fiber described in step S1 with a conductive material to form a first conductive layer, which serves as the source electrode;

[0019] S3. Coat the coaxial outer surface of the conductive fiber treated in step S2 with an insulating material, and after drying, form an insulating layer. Continue to coat the outer surface of the insulating layer with a conductive material to form a second conductive layer, which serves as the drain of the transistor. Drop a polymer solution between the drain and the source to form an active layer, which serves as the channel.

[0020] S4. Take the second conductive fiber as the gate, add gel electrolyte, and assemble it with the source and drain electrodes of the conductive fiber substrate after step S3 to form a transistor, thus obtaining a vertical fiber-based organic electrochemical transistor.

[0021] The beneficial effects of this invention are:

[0022] 1. The vertical fiber-based organic electrochemical transistor of the present invention includes conductive fibers. A first conductive layer is provided on one end surface of the conductive fiber as a source. An insulating layer is provided on the cylindrical surface of the conductive fiber, and the insulating layer is coaxially disposed with the conductive fiber. A second conductive layer is provided on the surface of the insulating layer as a drain. A source layer is provided between the drain and the source as a channel. The transistor also includes a second conductive fiber as a gate. A gel electrolyte is provided between the gate and the source and drain. The present invention, by fabricating a vertical transistor structure and controlling the channel size, achieves a short channel that facilitates electron transport and migration while reducing the occurrence of short-channel effects in transistors. Compared with traditional fiber-based transistors, this vertical fiber-based organic electrochemical transistor reduces structural traps, improving transistor performance. This transistor can be widely used in fields such as smart wearables and biosensors.

[0023] 2. In the fabrication method of the vertical fiber-based organic electrochemical transistor of the present invention, the source electrode is disposed on one end surface of the conductive fiber, the insulating layer is disposed on the coaxial surface of the conductive fiber, and the drain electrode is coated on the surface of the insulating layer. The thickness of the insulating layer becomes the vertical distance between the source electrode and the drain electrode, and a source layer is disposed between the source and drain electrodes as a channel. The length of the channel is the thickness of the insulating layer. Therefore, by controlling the thickness of the insulating layer, the channel length of the transistor can be controlled, realizing the control of arbitrary dimensions of the channel length. Moreover, the method is simple and easy to implement, convenient for mass production, and has good prospects for industrial application.

[0024] 3. By coaxially arranging the drain, insulating layer, and conductive fiber, and making the channel between the drain and source ring-shaped, this invention effectively shortens the channel length while widening the channel thickness, mitigating the short-channel effect caused by the shorter channel length and reducing the adverse impact on the response speed of the organic electrochemical transistor. Furthermore, the structure of this vertical fiber-based transistor can reduce structural defect effects, significantly reducing the adverse effects of defect effects and short-channel effects on the stability and reliability of the transistor. This results in a vertical fiber-based organic electrochemical transistor with excellent overall performance, extending the transistor's lifespan and broadening its application areas.

[0025] 4. The method for preparing the vertical fiber-based organic electrochemical transistor provided by the present invention reduces the channel length by coating or spraying an insulating material onto the fiber and controlling its thickness. The method is simple to operate and the assembly materials are inexpensive and readily available, providing unlimited possibilities for the subsequent practical application of the transistor. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of a vertical fiber-based organic electrochemical transistor according to the present invention.

[0027] Figure 2 This is a schematic diagram of the source and drain cross-sectional structure of a vertical fiber-based organic electrochemical transistor according to the present invention.

[0028] Figure 3 This is an electron microscope image of the fiber cross-section after the insulating layer has been coated in Embodiment 1 of the present invention.

[0029] Figure 4 The output curve of the vertical fiber-based organic electrochemical transistor prepared in Example 1 of the present invention is shown.

[0030] Figure 5 The graph shows the transfer and transconductance curves of the vertical fiber-based organic electrochemical transistor prepared in Example 1 of this invention.

[0031] Figure Labels

[0032] 100 - Vertical fiber-based organic electrochemical transistor; 110 - Conductive fiber; 120 - Source; 130 - Insulating layer; 140 - Drain; 150 - Channel; 160 - Gate; 170 - Gel electrolyte. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0035] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0036] Please see Figures 1-2 As shown, a vertical fiber-based organic electrochemical transistor 100 includes a conductive fiber 110. One end surface of the conductive fiber 110 is provided with a first conductive layer as a source 120. An insulating layer 130 is provided on the cylindrical surface of the conductive fiber 110, and the insulating layer 130 is coaxially arranged with the conductive fiber 110. A second conductive layer is provided on the surface of the insulating layer 130 as a drain 140. A source layer is provided between the drain 140 and the source 120 as a channel 150. The transistor also includes a second conductive fiber as a gate 160. A gel electrolyte 170 is provided between the gate 160 and the source 120 and the drain 140. This invention coaxially arranges the drain 140, insulating layer 130, and conductive fiber 110, with the channel between the drain 140 and source 120 being annular. This effectively shortens the length of the channel 150 while widening its thickness, mitigating the short-channel effect caused by the shorter channel 150 and reducing its adverse impact on the response speed of the organic electrochemical transistor. Furthermore, the structure of this vertical fiber-based transistor reduces structural defect effects, significantly mitigating the potential adverse effects of defect effects and short-channel effects on transistor stability and reliability. This results in a vertical fiber-based organic electrochemical transistor with excellent overall performance, extending the transistor's lifespan and expanding its application areas.

[0037] Specifically, the first conductive layer serving as the source 120 and the second conductive layer serving as the drain 140 are coaxially arranged, and the thickness of the insulating layer 130 is greater than 10 nm. The thickness of the insulating layer 130 is the vertical distance between the drain 140 and the source 120, which is the length of the channel 150. The second conductive layer, the insulating layer 130, and the conductive fiber 110 are all coaxially arranged. In this invention, the thickness of the insulating layer 130 of the transistor is the length of the channel 150. Since the thickness is easier to control than the length, the channel size of the fiber-based organic electrochemical transistor can be controlled, and the shortest channel is 10 nm. A short channel is beneficial for electron transport and migration, which is beneficial for improving the performance of the transistor.

[0038] The active layer of the transistor is a mixture of PEDOT:PSS and graphene oxide, with a volume ratio of PEDOT:PSS to graphene oxide of (0.5~2):1; the concentration of PEDOT:PSS is 1wt%~2wt%; and the concentration of graphene oxide is 0.1wt%~0.5wt%. By limiting the composition of the active layer to PEDOT:PSS and graphene oxide, as well as their ratio and concentration, the trapping effect of the active layer can be reduced from the source, thereby improving the performance of the transistor.

[0039] In some specific embodiments, the conductive fiber 110 includes one of carbon fiber, composite conductive fiber or flexible conductive fiber.

[0040] In some specific embodiments, the gel electrolyte 170 includes several or all of polyvinyl alcohol, sodium poly(p-styrene sulfonate), ethylene glycol, sorbitol, and deionized water.

[0041] In some specific embodiments, the insulating layer 130 includes one or more of silicone rubber, insulating varnish, or transparent adhesive.

[0042] In some specific embodiments, the first conductive layer and the second conductive layer include one of the following: silver paste, copper particles, platinum, silver nanowires, conductive tape, etc.

[0043] A method for fabricating a vertical fiber-based organic electrochemical transistor includes the following steps:

[0044] S1. Perform surface cleaning treatment on conductive fiber 110 and dry it for later use;

[0045] S2. Coat one end of the conductive fiber 110 from step S1 with a conductive material to form a first conductive layer, which serves as the source electrode 120.

[0046] S3. Coat the coaxial outer surface of the conductive fiber 110 after step S2 with an insulating material, and after drying, form an insulating layer 130. Coat the outer surface of the insulating layer 130 with a conductive material to form a second conductive layer, which serves as the drain 140 of the transistor. Add a polymer solution between the drain 140 and the source 120 to form an active layer, which serves as the channel 150.

[0047] S4. Take the second conductive fiber as the gate 160, add gel electrolyte 170, and assemble it with the source and drain electrodes of the conductive fiber 110 substrate after step S3 to form a transistor, thus obtaining the vertical fiber-based organic electrochemical transistor 100.

[0048] In this fabrication method, the source electrode 120 is disposed on one end surface of the conductive fiber 110, the insulating layer 130 is disposed on the coaxial surface of the conductive fiber 110, and the drain electrode 140 is coated on the surface of the insulating layer 130. The thickness of the insulating layer 130 is the vertical distance between the source electrode 120 and the drain electrode 140. A source layer is disposed between the source and drain electrodes as a channel 150, and the length of the channel 150 is the thickness of the insulating layer 130. Therefore, by controlling the thickness of the insulating layer 130, the length of the transistor channel 150 can be controlled, realizing arbitrary control of the length of the channel 150. The method is simple and easy to implement, convenient for mass production, and has good prospects for industrial application.

[0049] It should be noted that, theoretically, this method can control the insulating layer 130 to any thickness, meaning that the length of the channel 150 can be infinitely small. However, in practice, due to the influence of the fabrication process and existing methods, the thickness of the insulating layer 130 is limited to more than 10 nm to ensure the successful fabrication of the channel 150 structure and to ensure the performance of the final transistor.

[0050] Example 1

[0051] This embodiment provides a method for fabricating a vertical fiber-based organic electrochemical transistor, including the following steps:

[0052] S1. Soak the carbon fiber in deionized water, anhydrous ethanol and acetone in sequence for 15 minutes for ultrasonic cleaning. After each cleaning, dry it before the next surface cleaning treatment. Finally, clean it with acetone and dry it for later use.

[0053] S2. Coat one end of the carbon fiber bundle in step S1 with silver paste to form a first conductive layer, which serves as the source electrode 120.

[0054] S3. Coat the coaxial outer surface of the carbon fiber bundle treated in step S2 with a layer of silicone rubber, and after drying, form an insulating layer 130. Continue to coat the outer surface of the insulating layer 130 with conductive silver paste to form a second conductive layer, which serves as the drain 140 of the transistor. Drop a polymer solution between the drain 140 and the source 120 to form an active layer, which serves as the channel 150. The organic polymer is 1.3 wt% PEDOT:PSS and 0.5 wt% graphene oxide, with a volume ratio of 1:1.

[0055] S4. Take another carbon fiber bundle after decontamination treatment as the gate 160, add gel electrolyte 170, and assemble it with the source and drain electrodes of the carbon fiber bundle as the substrate after step S3 to form a transistor, thus obtaining a vertical fiber-based organic electrochemical transistor 100.

[0056] Please see Figure 3 The image shown is an electron microscope image of the fiber cross-section after the insulating layer is coated in Example 1. As can be seen from the image, the carbon fiber bundle is wrapped with insulating material to form an insulating layer of a certain thickness. The thickness of the insulating layer is the channel length of the transistor. By controlling the thickness of the insulating layer, the channel length of the transistor can be controlled more easily, thereby increasing the transconductance of the transistor. The larger the transconductance, the greater the amplification of the input signal by the transistor and the better its performance.

[0057] Please see Figure 4 The figure shows the output curve of the vertical fiber-based organic electrochemical transistor prepared in Example 1. As can be seen from the figure, the transistor's on-state current reaches 42.9 mA. The curve exhibits a depletion mode, meaning that when the gate voltage is constant, the output current gradually increases with the increase of the source-drain voltage, and the curve shows a good linear trend. When the source-drain voltage is constant, the output current gradually decreases with the increase of the gate voltage, indicating that the prepared vertical fiber-based organic phototransistor has good operating performance.

[0058] Please see Figure 5 The figure shows the transfer and transconductance curves of the vertical fiber-based organic electrochemical transistor prepared in Example 1. From the transfer curves, it can be seen that when the source-drain voltage is constant, the source-drain current gradually decreases as the gate voltage increases, which is consistent with the working principle of a transistor. Figure 3 The output curves are consistent; it can be seen from the transconductance curve that at V g At 0.5V, the transconductance reaches its maximum value of 61.8mS, indicating that the device has excellent amplification efficiency for the input signal.

[0059] Examples 2-6

[0060] Examples 2-6 provide a method for preparing a vertical fiber-based organic electrochemical transistor. The difference from Example 1 is that in step S3, the concentrations of the organic polymer PEDOT:PSS and the volume ratio of graphene oxide are shown in the table below. The rest is roughly the same as in Example 1 and will not be repeated here.

[0061] Comparative Examples 1-4

[0062] Comparative Examples 1-4 provide a method for preparing a vertical fiber-based organic electrochemical transistor. The difference from Example 1 is that in step S3, the concentrations of the organic polymer PEDOT:PSS and the volume ratio of graphene oxide are shown in the table below. The rest is roughly the same as in Example 1 and will not be repeated here.

[0063] Table 1. Process parameter settings for Examples 2-6 and Comparative Examples 1-4

[0064]

[0065] The performance of the vertical fiber-based organic electrochemical transistors prepared in Examples 1-6 and Comparative Examples 1-4 was tested, and the results are shown in the table below.

[0066] Table 2. Transistor performance test results of Examples 2-6 and Comparative Examples 1-4

[0067]

[0068] As shown in Table 2, the transistor performance of Examples 1-3 was analyzed, and V... PEDOT:PSS With V 氧化石墨烯 Decreasing the proportion will reduce transistor performance because it reduces ion transport efficiency; the transistor performance in Example 3 has reached saturation, and further increasing the proportion will not increase transistor performance.

[0069] Analysis of the transistor performance of Examples 4 and 5 and Comparative Examples 1 and 2 revealed that both increasing and decreasing the concentration of PEDOT:PSS led to a decrease in transistor performance. This is because a decrease in the concentration of PEDOT:PSS reduces its conductivity. In Comparative Example 1, when only graphene oxide was used, the resulting device did not possess transistor performance. In Comparative Example 2, when the concentration of PEDOT:PSS was too high, it led to excessive deposition, which was detrimental to ion transport.

[0070] Analysis of the transistor performance of Example 6 and Comparative Examples 3 and 4 revealed that the absence of graphene oxide, excessively low or excessively high concentrations of graphene oxide all led to a decrease in device performance. The absence of graphene oxide or excessively low concentrations of graphene oxide resulted in a decrease in conductivity, which was detrimental to ion transport. While excessively high concentrations of graphene oxide improved the conductivity of the transistor, they also reduced its transconductance and on / off ratio.

[0071] Example 7

[0072] This embodiment provides a method for preparing a vertical fiber-based organic electrochemical transistor. The difference from Embodiment 1 is that the fiber used is a composite conductive fiber. The rest is roughly the same as Embodiment 1 and will not be repeated here.

[0073] Example 8

[0074] This embodiment provides a method for fabricating a vertical fiber-based organic electrochemical transistor. The difference from Embodiment 1 is that the conductive material of the transistor source and drain is platinum. The rest is roughly the same as in Embodiment 1 and will not be described again here.

[0075] In summary, this invention provides a vertical fiber-based organic electrochemical transistor and its fabrication method. By placing the source electrode on one end surface of a conductive fiber, an insulating layer on the coaxial surface of the conductive fiber, and coating the drain electrode on the surface of the insulating layer, the thickness of the insulating layer becomes the vertical distance between the source and drain electrodes. A source layer is positioned between the source and drain electrodes as a channel, and the length of the channel is equal to the thickness of the insulating layer. Therefore, by controlling the thickness of the insulating layer, the channel length of the transistor can be controlled, achieving arbitrary control of the channel length. This invention, by coaxially arranging the drain electrode with the insulating layer and conductive fiber, and making the channel between the drain and source electrodes annular, effectively shortens the channel length while widening the channel thickness, mitigating the short-channel effect caused by the shorter channel length and reducing its adverse impact on the response speed of the organic electrochemical transistor. Furthermore, the structure of this vertical fiber-based transistor reduces structural defect effects, significantly mitigating the adverse effects of defect effects and short-channel effects on transistor stability and reliability, resulting in a vertical fiber-based organic electrochemical transistor with excellent overall performance. This method is simple to implement, easy to mass-produce, uses inexpensive and readily available assembly materials, and the transistors produced can be widely used in fields such as smart wearables and biosensors.

[0076] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A vertical fiber-based organic electrochemical transistor, characterized in that, The transistor includes conductive fibers, one end of which has a first conductive layer as a source electrode, and an insulating layer on its cylindrical surface, which is coaxially arranged with the conductive fibers. A second conductive layer is provided on the surface of the insulating layer as a drain electrode, and a source layer is provided between the drain electrode and the source electrode as a channel. The thickness of the insulating layer is the vertical distance between the drain electrode and the source electrode, and is the length of the channel. The transistor also includes a second conductive fiber as a gate electrode, and a gel electrolyte is provided between the gate electrode and the source and drain electrodes.

2. The vertical fiber-based organic electrochemical transistor according to claim 1, characterized in that, The first conductive layer, serving as the source, and the second conductive layer, serving as the drain, are coaxially disposed; the thickness of the insulating layer is greater than 10 nm.

3. The vertical fiber-based organic electrochemical transistor according to claim 1, characterized in that, The second conductive layer, the insulating layer, and the conductive fiber are all coaxially arranged.

4. The vertical fiber-based organic electrochemical transistor according to claim 1, characterized in that, The active layer is a mixture of PEDOT:PSS and graphene oxide, and the volume ratio of PEDOT:PSS to graphene oxide is (0.5~2):

1.

5. The vertical fiber-based organic electrochemical transistor according to claim 4, characterized in that, The concentration of PEDOT:PSS is 1wt%~2wt%; the concentration of graphene oxide is 0.1wt%~0.5wt%.

6. The vertical fiber-based organic electrochemical transistor according to claim 1, characterized in that, The conductive fiber is a composite conductive fiber or a flexible conductive fiber.

7. The vertical fiber-based organic electrochemical transistor according to claim 6, characterized in that, The flexible conductive fiber is carbon fiber.

8. The vertical fiber-based organic electrochemical transistor according to claim 1, characterized in that, The gel electrolyte includes several or all of polyvinyl alcohol, sodium poly(p-styrene sulfonate), ethylene glycol, sorbitol, and deionized water.

9. The vertical fiber-based organic electrochemical transistor according to claim 1, characterized in that, The insulating layer includes one or more of silicone rubber, insulating varnish, or transparent adhesive.

10. The vertical fiber-based organic electrochemical transistor according to claim 1, characterized in that, The first conductive layer and the second conductive layer include one of silver paste, platinum, silver nanowires, and conductive tape.

11. A method for preparing a vertical fiber-based organic electrochemical transistor according to any one of claims 1 to 10, characterized in that, Includes the following steps: S1. Perform surface cleaning treatment on the conductive fibers and dry them for later use; S2. Coat one end of the conductive fiber described in step S1 with a conductive material to form a first conductive layer, which serves as the source electrode; S3. Coat the coaxial outer surface of the conductive fiber treated in step S2 with an insulating material, and after drying, form an insulating layer. Continue to coat the outer surface of the insulating layer with a conductive material to form a second conductive layer, which serves as the drain of the transistor. Drop a polymer solution between the drain and the source to form an active layer, which serves as the channel. The thickness of the insulating layer is the vertical distance between the drain and the source, and is the length of the channel; S4. Take the second conductive fiber as the gate, add gel electrolyte, and assemble it with the source and drain electrodes of the conductive fiber substrate after step S3 to form a transistor, thus obtaining a vertical fiber-based organic electrochemical transistor.

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