Organic electrochemical transistor with high cycling stability and preparation method thereof

Abstract

The invention discloses an organic electrochemical transistor with high cycling stability and a preparation method thereof. The organic electrochemical transistor mainly comprises a substrate, a source electrode, a cross-linking agent doped semiconductor layer, a drain electrode, a packaging layer, an electrolyte layer and a grid electrode, in the preparation process, a vertical structure mode is adopted, and the substrate is prepared, cleaned and dried; sequentially preparing a source electrode on the substrate, preparing a cross-linking agent doped semiconductor layer on the source electrode, preparing a drain electrode on the cross-linking agent doped semiconductor layer, preparing a packaging layer on the drain electrode, exposing the whole area of the vertical stacking part of the drain electrode and the source electrode and the area of the cross-linking agent doped semiconductor layer, and preparing an electrolyte layer above the packaging layer; and finally preparing a grid electrode connected with the electrolyte layer. According to the method disclosed by the invention, the composite cross-linking agent which is homogeneously mixed and heterogeneously mixed with the organic composite ion-electronic semiconductor is simultaneously introduced into the organic composite ion-electronic semiconductor, and through photo-crosslinking curing, effective doping of ions in the semiconductor is promoted, and long-term stable operation of the device is also ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic electrochemical transistors, and particularly relates to an organic electrochemical transistor with high cycle stability and a preparation method thereof. Background Art

[0002] Organic Electrochemical Transistors (OECTs) can control carriers through field effect, chemical, and / or electrochemical doping methods. Compared with traditional Organic Field-Effect Transistors (OFETs), they have advantages such as good biocompatibility, low driving voltage, and high transconductance. As efficient ion-electron transducers, they have received extensive research attention in bioelectronics fields such as electrophysiological signal recording, brain-computer interfaces, and cell monitoring. Although high carrier mobility and high capacitance are required to achieve high-performance bioelectronic devices, the stable operation of Organic Mixed Ionic-Electronic Conductor (OMIEC) is also very important. OMIEC is the core component of OECT. The operation of OECT depends on ion diffusion and charge carrier transport in OMIEC. However, this process will inevitably cause irreversible damage to the microstructure of OMIEC. The degradation of OECT may be caused by several different mechanisms, that is, excessive absorption of water molecules destroys the mutual physical interaction between polymer chains, parasitic side reactions reduce the efficiency of the Faraday charge-discharge process, and bias stress on the source / drain may lead to degradation of the interface properties and accelerate the degradation of OECT. Even in the absence of non-capacitive Faraday side reactions, the performance degradation of OECT based on OMIEC is also related to volume changes and structural degradation caused by repeated ion doping / dedoping cycles. Although continuous progress has been made in the research on the device physics and organic material properties of OECT, there is still a lack of OECTs with excellent cycle stability. However, achieving OECT with high cycle stability is a prerequisite for further improving its technology maturity and industrialization. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide an organic electrochemical transistor with high cycle stability and a preparation method thereof. On the one hand, it further promotes the effective doping of ions in the semiconductor, and on the other hand, it ensures the long-term stable operation of the device.

[0004] To solve the above technical problems, the specific technical solutions of the present invention are as follows:

[0005] An organic electrochemical transistor with high cycle stability, which successively includes, from bottom to top: a substrate, a source electrode, a crosslinker-doped semiconductor layer, a drain electrode, a packaging layer, an electrolyte layer, and a gate electrode;

[0006] A rectangular strip-shaped source electrode is arranged at the exact center of the substrate. A square crosslinker-doped semiconductor layer is arranged at the central position of the source electrode, and the width of the crosslinker-doped semiconductor layer is greater than that of the source electrode. A rectangular strip-shaped drain electrode perpendicular to the source electrode is arranged at the central position of the crosslinker-doped semiconductor layer, and the width of the drain electrode is less than that of the crosslinker-doped semiconductor layer. The drain electrode does not completely cover or block the crosslinker-doped semiconductor layer; A packaging layer is arranged on the drain electrode, and a square hole is opened at the exact center of the packaging layer. The size of the opening, observed from the top view, should satisfy the requirement of exposing all regions of the vertically stacked part of the drain electrode and the source electrode and the crosslinker-doped semiconductor layer region; The electrolyte layer covers the upper part of the packaging layer, and the size of the electrolyte layer only needs to satisfy the requirement of completely covering the square opening of the packaging layer; A gate electrode is arranged on the electrolyte layer, and the gate electrode is in full contact with the electrolyte layer.

[0007] Further, the substrate is one of glass, silicon wafer, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polydimethylsiloxane (PDMS), polyurethane (PU), or polyimide (PI).

[0008] Further, the preparation materials of the source electrode and the drain electrode are one of gold, platinum, carbon paste, carbon nanotubes, or graphene. The electrode width range of the source electrode and the drain electrode is 20 - 100 μm, and the electrode thickness range is 40 - 200 nm.

[0009] Further, the preparation materials of the gate electrode are one of gold, silver, silver / silver chloride, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), carbon nanotubes, graphene, or graphdiyne.

[0010] Further, the material of the crosslinker-doped semiconductor layer is prepared by mixing an organic composite ion-electron semiconductor with a composite crosslinker. The composite crosslinker is composed of at least two organic materials with photocrosslinking functions that can be homogeneously mixed or heterogeneously mixed with the organic composite ion-electron semiconductor respectively.

[0011] Further, the thickness range of the crosslinker-doped semiconductor layer is 50 - 200 nm.

[0012] Further, the packaging layer is composed of an electrochemically stable insulating material, specifically one of SU-8 photoresist, parylene-C, polystyrene (PS), polydimethylsiloxane (PDMS), styrene-ethylene-butylene-styrene (SEBS), or cinnamic acid-modified cellulose (Cinnamate-Cellulose).

[0013] Furthermore, the electrolyte layer is made of a solid or liquid electrolyte that does not have electron-conducting properties but has ion-conducting properties.

[0014] The present invention also provides a method for preparing an organic electrochemical transistor with high cycle stability, and the method includes the following steps:

[0015] Step S1: Clean, dry, and perform ultraviolet ozone treatment on the substrate to obtain a pretreated substrate.

[0016] Step S2: Prepare a patterned source electrode on the pretreated substrate;

[0017] Step S3: Perform ultraviolet ozone cleaning treatment on the substrate with the patterned source electrode;

[0018] Step S4: Spin-coat a mixed solution of an organic composite ion-electron semiconductor and a composite cross-linking agent prepared in proportion on the substrate with the patterned source electrode, cover it with a metal mask template with preset patterned holes, and continuously irradiate it under an ultraviolet light source to achieve photo-crosslinking curing, obtaining a cross-linking agent-doped semiconductor layer; Develop the cross-linking agent-doped semiconductor layer / source electrode / substrate after photo-crosslinking curing in a solvent to remove the semiconductor layer that has not been photo-crosslinked and cured, and dry it with nitrogen to obtain a patterned cross-linking agent-doped semiconductor layer;

[0019] Step S5: Prepare a patterned drain electrode on the patterned cross-linking agent-doped semiconductor layer;

[0020] Step S6: Prepare a packaging layer on the patterned drain electrode, and expose all regions of the vertically stacked part of the drain electrode and the source electrode and the region of the patterned cross-linking agent-doped semiconductor layer;

[0021] Step S7: Prepare an electrolyte layer on the packaging layer, prepare a gate electrode connected to the electrolyte layer, and finally prepare an organic electrochemical transistor with high cycle stability.

[0022] Compared with the prior art, the present invention has the following beneficial technical effects:

[0023] (1) The present invention adopts a vertical structure, sandwiching the cross-linking agent-doped semiconductor layer between the source electrode and the drain electrode, reducing the contact area between the cross-linking agent-doped semiconductor layer and the electrolyte layer, thereby slowing down the irreversible consumption of the cross-linking agent-doped semiconductor layer during the long-term cyclic operation of the OECT;

[0024] (2) The present invention introduces a cross-linking reagent into the organic composite ion-electron semiconductor. Through photo-crosslinking curing, precise patterning of the semiconductor layer can be simply and efficiently achieved, and a high organic semiconductor content can be maintained, greatly improving the response sensitivity and ensuring the high performance of the device;

[0025] (3) In the present invention, a crosslinker-doped semiconductor layer is obtained by mixing an organic composite ion-electron semiconductor and a composite crosslinker in proportion. Among them, the organic small molecules with photo-crosslinking function that are homogeneously mixed with the semiconductor can achieve precise patterning of the semiconductor layer through photo-crosslinking curing, promoting effective doping of ions. And the organic polymers with photo-crosslinking function that are heterogeneously mixed with the semiconductor can form a stable dielectric film through photo-crosslinking curing, resisting the short-circuit effect between the source and drain of the OECT, and effectively enhancing the cycling stability of the OECT;

[0026] (4) The preparation method of an organic electrochemical transistor with high cycling stability provided by the present invention has strong universality and is applicable to a variety of organic composite ion-electron semiconductors covering p-type and n-type, overcoming the problem of poor long-term cycling stability of OECT in traditional preparation methods;

[0027] (5) The preparation method of an organic electrochemical transistor with high cycling stability provided by the present invention is compatible with large-scale solution preparation methods, and can effectively reduce the preparation energy consumption and preparation cost. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0029] Figure 1 It is a cross-sectional view of the organic electrochemical transistor with high cycling stability of the present invention.

[0030] Figure 2 It is a hierarchical structure diagram of the organic electrochemical transistor with high cycling stability of the present invention.

[0031] Figure 3 It is a schematic diagram of the composition of the crosslinker-doped semiconductor layer of the organic electrochemical transistor with high cycling stability of the present invention.

[0032] Figure 4 It is the change of the drain current during the long-term cycling stability test.

[0033] Figure 5 It is the change of the transfer characteristic curve during the long-term cycling stability test.

[0034] Explanation of the marks in the figure: 1 - substrate; 2 - source; 3 - crosslinker-doped semiconductor layer; 4 - drain; 5 - encapsulation layer; 6 - electrolyte layer; 7 - gate. Detailed Embodiments

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0036] The present invention proposes an organic electrochemical transistor with high cycle stability, as Figure 1 shown, the organic electrochemical transistor sequentially includes from bottom to top: a substrate 1, a source electrode 2, a crosslinker-doped semiconductor layer 3, a drain electrode 4, a packaging layer 5, an electrolyte layer 6, and a gate electrode 7.

[0037] Figure 2 is a hierarchical structure diagram of the organic electrochemical transistor with high cycle stability of the present invention. In Figure 2 a rectangular strip-shaped source electrode 2 is arranged at the exact center of the substrate 1 shown in (a) of Figure 2 as shown in (b) of Figure 2 ; as shown in (c) of Figure 2 , a square crosslinker-doped semiconductor layer 3 is arranged at the central position of the source electrode 2, and the width of the crosslinker-doped semiconductor layer 3 is greater than the width of the source electrode 2; as shown in (d) of Figure 2 , a rectangular strip-shaped drain electrode 4 perpendicular to the source electrode 2 is arranged at the central position of the crosslinker-doped semiconductor layer 3, and the width of the drain electrode 4 is less than the width of the crosslinker-doped semiconductor layer 3, and the drain electrode 4 does not completely cover or block the crosslinker-doped semiconductor layer 3; as shown in (e) of Figure 2 , a packaging layer 5 is arranged on the drain electrode 4, and a square hole is opened at the exact center of the packaging layer 5. The size of the opening observed from the top view should meet the requirement of exposing all regions of the perpendicular stacking part of the drain electrode 4 and the source electrode 2 and the region of the crosslinker-doped semiconductor layer 3; as shown in (f) of

[0038] , an electrolyte layer 6 is covered above the packaging layer 5, and the size of the electrolyte layer 6 only needs to meet the requirement of completely covering the square opening of the packaging layer 5; a gate electrode 7 is arranged on the electrolyte layer 6, and the gate electrode 7 is in full contact with the electrolyte layer 6.

[0039] When a control signal is applied to the gate electrode 7 and under the action of the source-drain voltage between the source electrode 2 and the drain electrode 4, ions from the electrolyte layer 6 penetrate into or precipitate inside the crosslinker-doped semiconductor layer 3, thereby regulating the conductivity of the crosslinker-doped semiconductor layer 3 and realizing the control of the cyclic switching of the organic electrochemical transistor.

[0040] Further, the materials for preparing the source and drain are one of gold, platinum, carbon paste, carbon nanotubes or graphene. The electrode width range of the source and drain is 20-100 μm, and the electrode thickness range is 40-200 nm. The material for preparing the gate is one of gold, silver, silver / silver chloride, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate, carbon nanotubes, graphene or graphdiyne.

[0041] Further, the material of the crosslinker-doped semiconductor layer is prepared by mixing an organic composite ion-electron semiconductor and a composite crosslinker in proportion. The composite crosslinker is composed of at least two organic materials with photocrosslinking functions that can be homogeneously mixed or heterogeneously mixed with the organic composite ion-electron semiconductor respectively. The thickness range of the crosslinker-doped semiconductor layer is 50-200 nm, and the width of the crosslinker-doped semiconductor layer is greater than that of the source and drain. The organic composite ion-electron semiconductor is an organic semiconductor with a carrier-conducting main chain and redox activity that can provide and / or receive electrons.

[0042] Further, the composite crosslinker uses an organic material with photocrosslinking function, which can make the resulting crosslinker-doped semiconductor solution have photo-processability by mixing with the organic composite ion-electron semiconductor. The composite crosslinker can undergo a covalent crosslinking reaction through ultraviolet exposure, and the wavelength range of the used ultraviolet light is 10-450 nm, which specifically depends on the used organic material with photocrosslinking function. The organic material with photocrosslinking function has a functionalized ultraviolet absorption group, and the functionalized ultraviolet absorption group is one of cinnamate, dienecinnamate, coumarin, vinyl, allyl, acrylate, azide and oxetane groups. The organic materials with photocrosslinking function can be divided into small molecules and polymers. Among them, the organic small molecules with photocrosslinking function can achieve homogeneous mixing with the organic composite ion-electron semiconductor, and the organic polymers with photocrosslinking function can achieve heterogeneous mixing with the organic composite ion-electron semiconductor.

[0043] Further, the encapsulation layer is composed of an electrochemically stable insulating material, specifically one of photoresist SU-8, parylene-C, polystyrene (PS), polydimethylsiloxane (PDMS), styrene-ethylene-butylene (SEBS) or cinnamate-modified cellulose.

[0044] Further, the electrolyte layer uses a solid or liquid electrolyte that does not have electron-conducting characteristics but has ion-conducting characteristics.

[0045] Combined with the above materials, the preparation method of an organic electrochemical transistor with high cycle stability of the present invention will be described in detail. The preparation method is used to prepare the above-mentioned organic electrochemical transistor with high cycle stability, and specifically includes the following steps:

[0046] Step S1: Use isopropyl alcohol to ultrasonically clean the silicon wafer substrate shown in (a) for 15 minutes, and after drying the silicon wafer substrate with nitrogen, perform ultraviolet ozone treatment for 15 minutes to obtain a pretreated silicon wafer substrate. Figure 2 The silicon wafer substrate shown in (a) is ultrasonically cleaned with isopropyl alcohol for 15 minutes, and after drying the silicon wafer substrate with nitrogen, it is treated with ultraviolet ozone for 15 minutes to obtain a pretreated silicon wafer substrate.

[0047] Step S2: Adopt the mask evaporation method to sequentially evaporate 3 nm of chromium and 150 nm of gold on the pretreated silicon wafer substrate as the source electrode by thermal evaporation to obtain a patterned source electrode, and the width of the source electrode is 20 - 100 μm, as shown in (b). Figure 2 as shown in (b).

[0048] Step S3: Perform ultraviolet ozone cleaning treatment on the silicon wafer substrate with the patterned source electrode for about 15 minutes.

[0049] Step S4: Spin-coat the mixed solution of the organic composite ion-electron semiconductor and the composite cross-linking agent prepared in proportion on the substrate with the patterned source electrode.

[0050] In this step, the mixing ratio of the organic composite ion-electron semiconductor and the composite cross-linking agent is as follows: poly[thiophene-bis(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)-2,2'-bithiophene]: bis(2,2,2-trifluoroethyl)diazine: cinnamic acid modified cellulose Cinnamate-Cellulose = 6:2:1, where [thiophene-bis(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)-2,2'-bithiophene]: bis(2,2,2-trifluoroethyl)diazine is used as the organic composite ion-electron semiconductor, bis(2,2,2-trifluoroethyl)diazine is used as the photocrosslinkable small molecule, and cinnamic acid modified cellulose Cinnamate-Cellulose is used as the photocrosslinkable polymer.

[0051] The spin-coating conditions are as follows: the humidity is controlled below 10%, the spin-coating speed is 3000 rpm, and the spin-coating time is 20 s; subsequently, cover with a metal mask template with square holes, and the length and width of the square holes are both larger than the width of the source electrode and the drain electrode, and place them under ultraviolet light sources with wavelengths of 365 nm and 280 nm for continuous irradiation for 3 min and 2 min respectively to achieve photocrosslinking curing; finally, place the photocrosslinked and cured cross-linking agent doped semiconductor layer / source electrode / substrate in a chloroform solution for development for 3 - 5 s to remove the semiconductor layer that has not been photocrosslinked and cured, and dry it with nitrogen to obtain a patterned cross-linking agent doped semiconductor layer, as shown in (c). Figure 2 as shown in (c).

[0052] The schematic composition of the crosslinker-doped semiconductor layer is as follows Figure 3 shown, where Figure 3 (a) in it is the top view of the crosslinker-doped semiconductor layer, Figure 3 (b) in it is the side view of the crosslinker-doped semiconductor layer. Poly[thiophene-bis(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)-2,2'-bithiophene] is an organic composite ion-electron semiconductor, bistrifluoromethyl diazine is a photo-crosslinkable small molecule, and cinnamic acid-modified cellulose Cinnamate-Cellulose is a photo-crosslinkable polymer. As can be seen from Figure 3 , poly[thiophene-bis(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)-2,2'-bithiophene] and bistrifluoromethyl diazine are homogeneously mixed and crosslinked by the activation of double carbon-hydrogen bonds, while poly[thiophene-bis(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)-2,2'-bithiophene] and cinnamic acid-modified cellulose Cinnamate-Cellulose are heterogeneously mixed to form insulating pillars between the source and drain, resisting the short-circuit effect between the source and drain of the OECT.

[0053] Step S5: Use the mask evaporation method to evaporate and deposit 150 nm of gold on the patterned crosslinker-doped semiconductor layer to prepare the drain, and the width of the drain is 20 - 100 μm, and the length direction of the drain is perpendicular to the length direction of the source, as Figure 2 (d) in it shows;

[0054] Step S6: Spin-coat the entire surface of the device after the drain is prepared with a photo-crosslinkable encapsulation layer, and perform exposure treatment with 365 nm ultraviolet light, and expose all areas of the perpendicular stacking part of the drain and the source and the crosslinker-doped semiconductor layer area, as Figure 2 (e) in it shows;

[0055] Step S7: Drop about 30 μL of phosphate buffer solution PBS on the exposed crosslinker-doped semiconductor layer to be used as the electrolyte layer, and connect the gate through the electrolyte layer to prepare an organic electrochemical transistor with high cycle stability, as Figure 2 (f) in it shows.

[0056] Furthermore, silver / silver chloride is used as the gate.

[0057] Next, we use the prepared organic electrochemical transistor with high cycle stability for testing, and the test conditions are as follows:

[0058] Constant drain voltage V D =-0.1 V, source voltage V S =0 V (equivalent to grounding), and the gate-source voltage V GSet as a periodic pulse signal with a frequency of 10 Hz, a duty cycle of 0.5, and a level switching between +0.4 V and -0.4 V. Capture the output current to obtain the change of the drain current and draw a graph, as Figure 4 shown. At the same time, after every 5000 cycle periods, according to a consistent test procedure (i.e., V G is swept from +0.4 V to -0.4 V, then back from -0.4 V to +0.4 V, and fix V D =-0.1 V, V S =0 V) to capture the output current to obtain the transfer characteristics and draw a graph, as Figure 5 shown.

[0059] From Figure 5 's graphical results, it can be seen that under this test condition, the organic electrochemical transistor exhibits excellent cycle stability. During 240,000 cycle periods (24,000 seconds of operation time), the drain current always remains at a relatively high level (always remains at the -9.0 mA level), and there is no decline before and after the long-term cycle stability test (growing from -9.06 mA in the first cycle period to -9.25 mA in the 240,000th cycle period, retaining 102.10% of the initial drain current). At the same time, during this process, the drain current (solid line) can always be controlled between an order of magnitude from 10 -7 A to 10 -3 A, and the gate current (dashed line) always remains at a relatively low order of magnitude (close to 10 -6 A), always having a great current regulation effect.

[0060] It can be understood that the present invention is described through some embodiments. Those skilled in the art know that without departing from the spirit and scope of the present invention, various changes or equivalent replacements can be made to these features and embodiments. Additionally, under the teaching of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present invention.

Claims

1. An organic electrochemical transistor with high cycle stability, characterized in that The organic electrochemical transistor comprises, from bottom to top, a substrate, a source electrode, a cross-linking agent doped semiconductor layer, a drain electrode, an encapsulation layer, an electrolyte layer and a gate electrode; A rectangular strip source is arranged in the center of the substrate, a square cross-linker-doped semiconductor layer is arranged at the center of the source, and the width of the cross-linker-doped semiconductor layer is greater than the width of the source; a rectangular strip drain is arranged at the center of the cross-linker-doped semiconductor layer, which is perpendicular to the source, and the width of the drain is less than the width of the cross-linker-doped semiconductor layer, and the drain does not completely cover or block the cross-linker-doped semiconductor layer; an encapsulation layer is arranged on the drain, and a square hole is opened in the center of the encapsulation layer, and the size of the hole observed from the top view must meet the requirement of exposing the entire area of ​​the vertical stacking part of the drain and the source and the cross-linker-doped semiconductor layer area; an electrolyte layer is covered on the top of the encapsulation layer, and the size of the electrolyte layer only needs to meet the requirement of completely covering the square opening of the encapsulation layer; a gate is arranged on the electrolyte layer, and the gate is in full contact with the electrolyte layer.

2. The organic electrochemical transistor with high cycle stability according to claim 1, characterized in that: The substrate is one of glass, silicon wafer, polyethylene terephthalate PET, polyethylene naphthalate PEN, polydimethylsiloxane PDMS, polyurethane PU or polyimide PI.

3. The organic electrochemical transistor with high cycle stability according to claim 1, characterized in that: The source electrode and the drain electrode are made of one of gold, platinum, carbon paste, carbon nanotubes or graphene. The electrode width of the source electrode and the drain electrode ranges from 20 to 100 μm and the electrode thickness ranges from 40 to 200 nm.

4. The organic electrochemical transistor with high cycle stability according to claim 1, characterized in that: The gate is made of a material selected from the group consisting of gold, silver, silver / silver chloride, poly(3,4-ethylenedioxythiophene): polystyrene sulfonate, carbon nanotubes, graphene, and graphyne.

5. The organic electrochemical transistor with high cycle stability according to claim 1, characterized in that: The material of the crosslinker-doped semiconductor layer is prepared by mixing an organic composite ion-electron semiconductor and a composite crosslinker, and the composite crosslinker is composed of at least two organic materials with photo-crosslinking function that can be homogeneously mixed or heterogeneously mixed with the organic composite ion-electron semiconductor.

6. The organic electrochemical transistor with high cycle stability according to claim 5, characterized in that: The thickness of the cross-linking agent doped semiconductor layer is in the range of 50 to 200 nm.

7. The organic electrochemical transistor with high cycle stability according to claim 1, characterized in that: The encapsulation layer is made of an electrochemically stable insulating material, specifically one of photoresist SU-8, parylene-C, polystyrene PS, polydimethylsiloxane PDMS, polystyrene-ethylene-butylene SEBS or cinnamate-cellulose.

8. The organic electrochemical transistor with high cycle stability according to claim 1, characterized in that: The electrolyte layer uses a solid or liquid electrolyte that does not have electronic conductivity but has ion conductivity.

9. A method for preparing an organic electrochemical transistor with high cycle stability, characterized in that: The method comprises the following steps: Step S1: cleaning, drying, and ultraviolet ozone treating the substrate to obtain a pretreated substrate; Step S2: preparing a patterned source electrode on the pretreated substrate; Step S3: performing ultraviolet ozone cleaning treatment on the substrate with the patterned source electrode; Step S4: Spin-coating a mixed solution of an organic composite ion-electron semiconductor and a composite cross-linking agent prepared in proportion on a substrate with a patterned source electrode, covering it with a metal mask with holes in a preset pattern, and continuously irradiating it under an ultraviolet light source to achieve photo-cross-linking and curing to obtain a cross-linking agent-doped semiconductor layer; developing the cross-linking agent-doped semiconductor layer / source electrode / substrate after photo-cross-linking and curing in a solvent to remove the semiconductor layer that has not been photo-cross-linked and cured, and drying it with nitrogen to obtain a patterned cross-linking agent-doped semiconductor layer; Step S5: preparing a patterned drain electrode on the patterned cross-linking agent-doped semiconductor layer; Step S6: preparing an encapsulation layer on the patterned drain electrode, and exposing the entire region of the vertically stacked portion of the drain electrode and the source electrode and the patterned cross-linking agent-doped semiconductor layer region; Step S7: preparing an electrolyte layer on the encapsulation layer, preparing a gate connected to the electrolyte layer, and finally preparing an organic electrochemical transistor with high cycle stability.

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