Graft copolymer compatibilizer containing semiconductor and elastomer fragments and preparation, separation and application thereof

Abstract

The invention discloses a graft copolymer compatibilizer containing a semiconducting polymer and an elastomer fragment, and preparation, separation and application of the graft copolymer compatibilizer. The structural formula of the compatilizer is shown in the formula 1. According to the invention, a metal coupling reaction (Stille reaction or Suzuki reaction) is utilized to seal the end of a semiconductor polymer, and then the semiconductor polymer is grafted to an elastomer flexible segment to prepare a grafted copolymer compatibilizer containing semiconductor and elastomer segments, and the grafted copolymer compatibilizer is directly blended with a semiconductor material under the condition of not adding the elastomer segments, so that the p-type performance of the material can be inhibited, and the service life of the material is prolonged. Meanwhile, the n-type performance and the tensile property of the material are improved. Based on a'compatibility 'and'mixing' strategy, the problem of collaborative improvement of electrical and mechanical properties is solved. The strategy is designed and regulated according to the material microstructure and intermolecular interaction, electrical and mechanical properties are closely combined and unified, and a foundation is built for application of flexible electronic devices.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor conjugated polymers and elastomer polymers, and specifically focuses on the research of a unique graft copolymer "compatibility agent". This "compatibility agent" ingeniously integrates semiconductor polymer segments and elastomer segments. This invention elaborates on its preparation process, separation technology, and applications in related fields. Background Technology

[0002] Flexible and stretchable electronics, as a highly innovative and forward-looking scientific and technological field, has emerged from the highly interdisciplinary integration of multiple disciplines. It integrates cutting-edge knowledge and advanced technologies from materials science, electronic engineering, physics, chemistry, and biology. From a materials science perspective, it involves developing flexible materials with special properties, such as novel conductive polymers and nanocomposites. These materials ensure both good conductivity and excellent stretchability, providing the material basis for the construction of flexible and stretchable electronic devices. However, as an emerging field, it faces many problems and challenges, especially the contradiction between the severe lack of stretchable electronic materials and the ever-increasing application demands of next-generation information functional devices.

[0003] Regarding conjugated polymers, some p-type conjugated polymers, such as poly(3-hexylthiophene) and polymers based on diketopyrrolopyrrole, have been reported for use in skin-like devices. However, both p-type and n-type conjugated polymers have room for improvement in terms of material properties and application expansion. P-type conjugated polymers still have room for improvement in performance optimization, such as stability and mobility, while n-type semiconductor materials, due to their poor air stability, lower performance, rigidity, and limited material options, severely hinder the development of flexible and stretchable integrated circuits in the field of flexible and stretchable electronics. Therefore, developing a strategy to fabricate high-performance stretchable organic semiconductors suitable for various flexible and stretchable electronic devices, including intrinsically stretchable organic field-effect transistors (OFETs), is crucial. Summary of the Invention

[0004] Addressing the significant challenge of achieving compatibility between electrical and mechanical properties in the field of flexible and stretchable semiconductor materials, this invention introduces the concept of a "compatibility agent" from the perspectives of molecular design and material processing. A semiconductor-terminated prepolymer acts as a "compatibility agent" by grafting a semiconductor segment onto a polymer graft. The semiconductor segment and the conjugated polymer unit construct a stable electrical connection channel through π-π interactions, improving charge transport efficiency and ensuring electrical properties during stretching. The elastomer segment entangles with the elastomer polymer according to the principle of "like dissolves like," enhancing interactions and reducing irreversible slippage between chains during stretching. This overcomes the problems of mechanical property deterioration and short lifespan caused by plastic deformation in traditional materials, resulting in a material with good elasticity, fatigue resistance, and extended lifespan.

[0005] This invention provides a method for the preparation, separation, and application of a graft copolymer "compatibility agent" comprising semiconductor and elastomer segments. A semiconductor polymer is end-capped using a metal coupling reaction (Stille or Suzuki reaction) to obtain a semiconductor-endcapped prepolymer. This prepolymer is then combined with an ammonolysis reaction of an anhydride and an amine to combine the flexible elastomer segments with the semiconductor segments, thus preparing a graft copolymer "compatibility agent" containing both semiconductor polymer and elastomer segments. Simultaneously, the separation and purification process includes methods such as Soxhlet extraction and column chromatography to separate and purify this graft copolymer "compatibility agent," providing a simpler and more efficient strategy for the separation and purification of polar and non-polar polymers. Based on this unique "compatibility" strategy, the key problem of incompatibility between the electrical and mechanical properties of flexible and stretchable electronic materials is effectively solved. Flexible and stretchable field-effect transistors constructed using this strategy exhibit excellent device performance, significantly expanding their application prospects in a range of technological fields such as electronic skin, wearable devices, and implantable devices, and providing a pathway for their accelerated commercialization. Composite semiconductor films were prepared by blending different proportions of compatibilizers with conjugated polymers and elastomeric polymers. Their mechanical and electrical properties were investigated. The prepared flexible and stretchable devices did not exhibit performance degradation after being subjected to 150% strain in the tensile direction. Furthermore, their mobility remained relatively stable after multiple mechanical deformations at 50% strain. Simultaneously, the mechanical and electrical properties were studied by directly blending different proportions of compatibilizers with conjugated polymers. The prepared flexible and stretchable devices did not exhibit cracks after being subjected to 300% strain in the tensile direction.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a graft copolymer “compatibility” comprising semiconductor and elastomer segments.

[0008] The structural formula of the "compatibility agent" is shown in Formula 1:

[0009]

[0010] In structural formula 1, the elastomer segment refers to a segment that exhibits sufficient chain mobility and elasticity at the molecular level, with weak intermolecular interactions and grafted reactive groups. Examples include, but are not limited to, maleic anhydride-grafted ethylene-octene copolymer (POE-g-MAH), maleic anhydride-grafted ethylene propylene diene monomer (EPDM-g-MAH), and maleic anhydride-grafted styrene-ethylene / butene-styrene block copolymer (SEBS-g-MAH).

[0011] In the aforementioned structural formula 1, the semiconductor fragments are synthesized through metal coupling reactions into different conjugated polymers, including but not limited to: pyrrolopyrrole dione conjugated polymers, isoindigo conjugated polymers, naphthylimide conjugated polymers, perylene imide conjugated polymers, thiophene conjugated polymers, carbazole conjugated polymers, benzothiadiazole conjugated polymers, fluorene conjugated polymers, etc.

[0012] Preferably, A1 and A2 monomers are each independently selected from any structure of Formula 2 and functionally similar structural units extended based on this structure; wherein, n in the semiconductor segment is the number of repeating units of A1-A2.

[0013] Preferably, the Ar unit is a group that caps the semiconductor, containing a bromine atom and a reactive activating group such as an amino group or a hydroxyl group. This includes, but is not limited to, thiophene groups, thiophene-2-thiophene groups, bithiophene groups, etc.

[0014] In the synthesized "compatibilizer", the ratio (mass fraction) of semiconductor and elastomer units ranges from 1:12, 1:6, 1:3, to 1:1. Preferably, the optimal ratio is 1:3.

[0015]

[0016] Preferably, R in any monomer of Formula 2 is independently selected from any of the following: hydrogen, halogen atom, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, alkoxy or alkathioyl side chain; more preferably, R is selected from any of the following: substituted or unsubstituted alkyl, substituted or unsubstituted aryl, alkoxy or alkathioyl; even more preferably, R is selected from any of the following: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, n-hexyl, n-heptyl, n-octyl, isooctyl, n-nonyl The following compounds are listed: 2-decyltetradecyl, phenyl, fluorophenyl, bromophenyl, chlorophenyl, o-tolyl, p-tolyl, m-tolyl, o-ethylphenyl, p-ethylphenyl, m-ethylphenyl, o-isopropylphenyl, p-isopropylphenyl, m-isopropylphenyl, 1-naphthyl, 2-naphthyl, methylthio, ethylthio, propylthio, butylthio, pentylthio, hexylthio, heptylthio, octylthio, nonylthio, decylthio, methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy, octyloxy, nonoxy, decoxy, etc.

[0017] According to an embodiment of the present invention, the structural formula of the "compatibility agent" shown in Formula 1 can be selected from any of the following structures:

[0018]

[0019]

[0020] This invention synthesizes a target polymer "compatibility agent" by optimizing the different feed ratios of semiconductor fragments (conjugated polymers) and elastomer fragments.

[0021] In a second aspect, the present invention provides a method for preparing a polymer "compatibility agent" comprising semiconductor segments and elastomer segments as shown in Formula 1 above.

[0022] The method for preparing the polymer "compatibility agent" comprising semiconductor fragments and elastomer fragments as shown in Formula 1 provided by the present invention includes the following steps:

[0023] S1. Monomers A1 and A2 are polymerized through a coupling reaction, and a capping agent is added during the reaction to complete the capping, thus obtaining a semiconductor polymer fragment.

[0024] S2. The obtained semiconductor fragment is reacted with an elastomer containing reactive groups to obtain the final target product, "compatibilizer";

[0025] In S1, the monomers A1 and A2 used are specifically any monomer structure shown in Formula 2 and functionally similar structural units extended based on this monomer structure.

[0026] Preferably, the A1 portion is a thiophene-thiophene donor unit with the following structural formula:

[0027] The A2 portion is a pyrrolopyrroledione receptor unit with the following structural formula: Wherein R group is 2-decyltetradecyl;

[0028] Preferably, the end-capping group of S1 is a thiophene unit, with the structural formula as follows:

[0029] The "compatibility agent" in S2; the ratio (mass fraction) of semiconductor and elastomer units is 1:12, 1:6, 1:3, 1:1. Preferably, the optimal ratio is 1:3;

[0030] The elastomer segment exhibits sufficient segmental mobility and elasticity at the molecular level, with weak intermolecular interactions and grafted reactive groups. Examples include, but are not limited to, maleic anhydride-grafted ethylene-octene copolymer (POE-g-MAH), maleic anhydride-grafted ethylene propylene diene monomer (EPDM-g-MAH), and maleic anhydride-grafted styrene-ethylene / butene-styrene block copolymer (SEBS-g-MAH). Preferably, maleic anhydride-grafted styrene-ethylene / butene-styrene block copolymer (SEBS-g-MAH) is selected as the reactive elastomer.

[0031] The product obtained in S2 conforms to the structure of Formula 1, "compatibilizer".

[0032] The reaction route of the preferred embodiment of the above preparation method can be represented as reaction route (A):

[0033] Taking the preparation of the "compatibility agent" SEBS-g-PDPPTT as an example, the synthetic route (A) is as follows:

[0034]

[0035] The preparation method of the "compatibility agent" described above includes the following specific reaction steps (Stille reaction):

[0036] (a1) Under an inert gas atmosphere, a specific amount of brominated monomer and tin oxide monomer are accurately weighed, and an appropriate amount of catalyst and ligand are measured. Then they are added to the reaction solvent and mixed thoroughly to prepare a mixed reaction solution.

[0037] (a2) Under anhydrous and oxygen-free conditions, the reaction is heated and stirred. After reacting for a period of time, the prepared end-capping agent solution is added to the reaction solution, and the reaction is continued with heating and stirring.

[0038] (a3) After the reaction is complete, cool to room temperature, add a methanol solution containing a small amount of potassium fluoride to quench the reaction (to remove unreacted tin reagent), allow precipitation, collect the product, and dry it under nitrogen atmosphere.

[0039] (a4) Weigh the appropriate amount of conjugated polymer, catalyst and elastomer fragment obtained in step (3), and carry out ammonolysis reaction of the conjugated polymer obtained in step (a3) ​​in an inert atmosphere;

[0040] (a5) After the reaction is completed, the reaction solution is added to a methanol solution to settle. The resulting reaction system is then subjected to Soxhlet extraction in methanol, acetone, and n-hexane in sequence. The solution extracted from n-hexane is evaporated to dryness to obtain the crude product.

[0041] Furthermore, the method also includes a step of separating and purifying the obtained crude product, as follows:

[0042] (a6) The crude product is separated and purified by column chromatography. The nonpolar maleic anhydride-grafted styrene-ethylene / butene-styrene block copolymer (SEBS-g-MAH) can be eluted by column chromatography, thereby separating the target product.

[0043] (a7) The target product was eluted with methanol and dichloromethane in column chromatography. After drying, it was redissolved in dichloromethane and the silica gel was removed by filtration. The resulting solution was then dried to obtain a pure polymer "compatibilizer".

[0044] Further, in step (a1), the bromine monomer is selected from: 3,6-bis(5-bromothiophen-2-yl)-2,5-bis(2-decyltetradecyl)-2,5-dihydropyrrolo[3,4-c]pyrrolo-1,4-dione (synthesized according to existing literature); the tin monomer is selected from: 2,5-bis(trimethylstanyl)thieno[3,2-b]thiophene;

[0045] The molar ratio of the brominated monomer to the tin monomer can be 1:1.1 (with the brominated monomer being slightly less than the tin monomer), ensuring that both ends of the polymer are tin reagents that can react with the end-capping agent;

[0046] The catalyst and ligand units are tris(dibenzylideneacetone)dipalladium(O)[Pd2(dba)3] and tris(o-methylphenyl)phosphine P(o-tol)3. The amount of the catalyst is 1-5% of the molar amount of the tin monomer in the reaction system, and the molar ratio of the amount of the ligand to the amount of the catalyst is 2:1-8:1.

[0047] The reaction solvent can be one of chlorobenzene, toluene, xylene, etc., and preferably, chlorobenzene is selected as the reaction solvent.

[0048] Furthermore, in step (a2), the reaction temperature is 115-120°C, and the capping agent is added after 1 hour of reaction.

[0049] Furthermore, in step (a4), the added capping compound has the following structural formula: The molar ratio of the end-capping compound to the conjugated polymer is 1:1 to 1:1.05;

[0050] Furthermore, in step (a2), the quenching reaction is stirred for 1-3 hours and then subjected to Soxhlet extraction with methanol and acetone for 8-14 hours in sequence.

[0051] In step (a4), the reaction is carried out in a reaction solvent, which may be chlorobenzene, toluene, or xylene. Preferably, chlorobenzene is selected as the reaction solvent.

[0052] In step (a4), the molar amount of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide catalyst added is 1-2 times the anhydride content in the maleic anhydride-grafted styrene-ethylene / butene-styrene block copolymer (SEBS-g-MAH).

[0053] Furthermore, in step (a4), preferably, the temperature is increased to 60°C for 13 hours.

[0054] Furthermore, a small amount of methanol is added in step (a5) to settle the polymerized "compatibilizer".

[0055] Furthermore, in step (a5), the ground is subjected to Soxhlet extraction, and the remaining catalyst and other impurities are removed by methanol and acetone, and the desired product is extracted by n-hexane.

[0056] Furthermore, in step (a6), the eluent used in the column chromatography is a mixed solvent of methanol and dichloromethane, with the polarity gradually increasing from pure petroleum ether to pure dichloromethane, and then to a mixed solvent of methanol and dichloromethane (methanol:dichloromethane = 1:3, v / v).

[0057] Furthermore, in step (a6), the solution obtained by passing the methanol and dichloromethane mixture (methanol:dichloromethane = 1:3, v / v) through the column is further dissolved in pure dichloromethane. During the filtration process, it is essential to remove the silica gel completely (excess methanol causes some of the silica gel in the column to dissolve in the column pass liquid).

[0058] The present invention further provides a method for preparing the above-mentioned stretchable film, comprising the following steps:

[0059] (a) First, the "compatibility agent" provided by the present invention is added to a mixed solution of polymer semiconductor and elastomer in a certain proportion, and a blended semiconductor thin film is prepared on a substrate by spin coating. After annealing, electrodes are deposited to prepare transistors, and the electrical performance is tested. Moreover, the "compatibility agent" can be directly added to the polymer semiconductor solution, and a directly blended semiconductor thin film can be prepared on a substrate by spin coating. After annealing, electrodes are deposited to prepare transistors, and the electrical performance is tested.

[0060] (b) Preparation of an elastic substrate for transfer blending of semiconductor thin films;

[0061] (c) The blended semiconductor thin film was transferred using an elastic substrate and stretched under different forces before being transferred back to the target substrate. The morphology was observed using an optical microscope and an atomic force microscope.

[0062] Further, in step (a), the polymer semiconductor, elastomer and "compatibility agent" are dissolved by heating to 90°C using chlorobenzene as a solvent at a concentration of 10 mg / ml.

[0063] Further, in step (a), the polymer semiconductor may be selected from at least one of the following: NDI-DTE molecule, N2200; the elastomer may be selected from: SEBS.

[0064] Further, in step (a), the semiconductor in the direct blend of the polymer semiconductor can be selected from at least one of the following: PNFFN-FDTE molecule, N2200;

[0065] The mass ratio of the polymer semiconductor to the elastomer can be 1:(1-100), preferably 1:1.

[0066] The amount of the "compatibility agent" added is 10%-60% of the total mass of the polymer semiconductor and the elastomer, preferably 30%.

[0067] In the direct mixing, the amount of "compatibility agent" added is 0%-70% of the mass of the polymer semiconductor, preferably 70%.

[0068] According to an embodiment of the present invention, further, in step (a), the polymer semiconductor is NDI-DTE and the elastomer is SEBS. NDI-DTE and SEBS are physically blended in a certain ratio, with mass ratios (NDI-DTE:SEBS) of 1:0, 3:1, 1:1, 3:7, and 1:9. Preferably, based on a blending ratio of 1:1 for NDI-DTE and SEBS, a compatibilizer is added, with the mass of the compatibilizer being 10%-60% of the total mass of the NDI-DTE semiconductor polymer and the SEBS elastomer, specifically 10%, 30%, and 60%. In the direct blending portion of step (a), the polymer semiconductor is PNFFN-FDTE, and the compatibilizer and semiconductor are directly physically blended in a certain ratio, with mass ratios (PNFFN-FDTE:compatibilizer) of 1:0, 5:5, and 3:7.

[0069]

[0070] Further, in step (a), the spin coating conditions are set to 2000 rpm for 60 s, and the annealing conditions are set to 200 °C for 30 min;

[0071] Furthermore, in step (a), among the various "compatibilizers", the "compatibilizer" with a semiconductor and elastomer unit ratio of 1:3 observed under an optical microscope is the best for improving the phase separation of the semiconductor and elastomer; in the direct blending portion, the 3:7 blend film is the best for improving the performance of FNFFN-FDTE.

[0072] Further, in step (a), gold electrodes are deposited on the surface of the thin film to fabricate a transistor device with a bottom gate top contact structure, and its electrical performance is tested;

[0073] Further, in step (c), the elastic substrate is PDMS, which is prepared by mixing the PDMS precursor with Dow Corning SYLGARD 184 curing agent at a mass ratio of 15:1, pouring it into a glass petri dish, curing it at 80°C for 12 hours, and then cutting it into strips for later use.

[0074] Further, in step (d), a PDMS substrate is attached to the spin-coated film, quickly peeled off, and then placed on a stretching device to stretch it with different forces including 0%, 50%, 100%, 150%, and 300%. It is then transferred to an unmodified silicon wafer (i.e., the target substrate), and the morphological changes are observed under a microscope.

[0075] The present invention further provides a method for fabricating the above-described fully stretchable transistor, comprising the following steps:

[0076] (a) First, the “compatibility agent” provided by the present invention is added to the mixed solution of polymer semiconductor and elastomer in a certain proportion. Alternatively, the “compatibility agent” can be added to the polymer semiconductor solution in a certain proportion. The blended semiconductor film is then prepared on a SiO2 / Si substrate by spin coating and placed on a hot stage for annealing in a nitrogen atmosphere.

[0077] (b) Fabricating an elastic substrate for a fully stretchable transistor;

[0078] (c) Fabricating an elastic dielectric layer for a fully stretchable transistor on a silicon substrate;

[0079] (d) Patterning is performed on a silicon substrate, followed by spraying CNT electrodes as gates;

[0080] (e) The CNT gate is transferred down using a flexible substrate, followed by the transfer of the dielectric layer from the silicon substrate, and finally the semiconductor layer is transferred layer by layer.

[0081] (f) Spraying CNT electrodes onto the semiconductor surface as source and drain electrodes;

[0082] Further, in step (a), the polymer semiconductor, elastomer and "compatibility agent" are dissolved by heating to 90°C using chlorobenzene as a solvent at a concentration of 10 mg / ml.

[0083] Further, in step (a), the polymer semiconductor may be selected from at least one of the following: NDI-DTE molecule, N2200; the elastomer may be selected from: SEBS;

[0084] Further, in step (a), the semiconductor in the direct blend of the polymer semiconductor can be selected from at least one of the following: PNFFN-FDTE molecule, N2200;

[0085] The mass ratio of the polymer semiconductor to the elastomer can be 1:(1-100), preferably 1:1.

[0086] The amount of the "compatibility agent" added is 10%-60% of the total mass of the polymer semiconductor and the elastomer, preferably 30%.

[0087] According to an embodiment of the present invention, further, in step (a), the polymer semiconductor is NDI-DTE and the elastomer is SEBS. NDI-DTE and SEBS are physically blended in a certain ratio, with mass ratios (NDI-DTE:SEBS) of 1:0, 3:1, 1:1, 3:7, and 1:9. Preferably, based on a blending ratio of 1:1 for NDI-DTE and SEBS, a compatibilizer is added. The mass of the compatibilizer added is 10%-60% of the total mass of the NDI-DTE semiconductor polymer and the SEBS elastomer, specifically 10%, 30%, and 60%.

[0088] Further, according to an embodiment of the present invention, in step (a), the polymer semiconductor directly mixed is PNFFN-FDTE, and PNFFN-FDTE and "composite agent" are physically blended in a certain proportion, with mass ratios (PNFFN-FDTE: "composite agent") of 1:0, 5:5, and 3:7 respectively.

[0089] Further, in step (b), the elastic substrate is SEBS1221. SEBS particles are dissolved in toluene at a concentration of 250 mg / ml, poured into a mold to obtain the SEBS substrate, and then cut into 2 cm × 2 cm pieces.

[0090] Further, in step (c), the elastic dielectric layer is SEBS1052. SEBS particles are dissolved in toluene at a concentration of 70 mg / ml, spin-coated onto an OTS-modified silicon substrate at a speed of 1000 r, and then annealed in an oven at 100°C for 80 min.

[0091] Further, in step (d), the silicon substrate is patterned using tape, then CNT solution is sprayed on, and annealed at 90°C for 5 min;

[0092] Further, in step (f), the CNT solution is diluted with deionized water to a concentration of 0.2 wt%, a mask is used, and then CNTs are sprayed onto a semiconductor thin film to prepare stretchable source and drain electrodes.

[0093] Compared with the prior art, the present invention has the following beneficial technical effects:

[0094] This invention prepares polymer "compatibilizers" based on semiconductor polymers and elastomer fragments, selecting different types of conjugated polymers and different elastomer structures. Different types of polymer "compatibilizers" were prepared. One "compatibilizer" with optimal mechanical properties was selected and blended with different types of conjugated polymers and elastomers to obtain blended composite semiconductor films with excellent mechanical and electrical properties. The blended films can be stretched by more than 150%, and under a fixed 50% strain, their electrical properties remain stable and higher than the initial properties after 500 cycles of stretching, providing new ideas for future research on stretchable semiconductor systems. Furthermore, the graft copolymers can also be directly blended with n-type polymers to improve the stretchability of polymer semiconductors. Attached Figure Description

[0095] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0096] Figure 1 This is a physical blending method for the conjugated polymer, "compatibility agent", and elastomer in the embodiments of the present invention;

[0097] Figure 2 The infrared spectra of SEBS, polymer NDI-DTE, elastomer fragment SEBS-g-MAH, semiconductor fragment PDPPTT-NH2, and "compatibilizer SEBS-g-PDPPTT" in Example 1 of this invention are shown below.

[0098] Figure 3 The UV absorption spectra of "compatibilizer SEBS-g-PDPPTT" at different mass feeding ratios in Example 1 of this invention;

[0099] Figure 4 The optical microscope morphology of the blend films with different compatibilizers prepared in Example 1 of the present invention shows that the compatibilizer with a ratio of semiconductor to elastomer units of 1:3 is the best for improving the phase separation of semiconductor and elastomer.

[0100] Figure 5 Atomic force microscopy images of the blend films prepared in Example 1 of this invention with different proportions of "compatibilizer" added;

[0101] Figure 6 This document summarizes the electrical properties and transfer curves of the blend films prepared in Example 1 of this invention with different proportions of "compatibilizer" added; the addition of "compatibilizer" increases the mobility and the on / off ratio compared to the initial mobility.

[0102] Figure 7 The images shown are atomic force microscopy images of the composite blend film of NDI-DTE and SEBS with a blend ratio of 50:50 (mass ratio) prepared in Comparative Example 1 of this invention under different stretching conditions (50%, 100%, 150%, 200%). Large cracks appeared at 100% strain.

[0103] Figure 8 The images show optical micrographs of the composite blend film prepared in Example 1 of this invention, consisting of a compatibilizer, a semiconductor conjugated polymer, and an elastomer SEBS in a blend ratio of 30:50:50 (mass ratio), under different stretching conditions (50%, 100%, 150%, 200%). Cracks appeared under 200% stretching.

[0104] Figure 9 The structure diagram and transfer curve of the thin-film fully flexible transistor based on the composite blend of "compatibility agent", semiconductor conjugated polymer NDI-DTE and elastomer SEBS in a blend ratio of 30:50:50 (mass ratio) prepared in Example 1 of the present invention are shown.

[0105] Figure 10 The images show the transfer curves of the fully flexible thin-film transistor prepared in Example 1 of this invention, based on a composite blend of "compatibility agent", semiconductor conjugated polymer NDI-DTE and elastomer SEBS in a blend ratio of 30:50:50 (mass ratio), under different strains, parallel (left) to the stretching direction and perpendicular (right) to the stretching direction.

[0106] Figure 11 The images show the transfer curves of the fully flexible thin-film transistor prepared in Example 1 of this invention, based on a 50:50 (mass ratio) blend of semiconductor conjugated polymer NDI-DTE and elastomer SEBS, under different strains, parallel (left) to the stretching direction and perpendicular (right) to the stretching direction.

[0107] Figure 12 The mobility variation curves of the two types of fully flexible transistors prepared in Example 1 of the present invention, which are parallel ( / / ) and perpendicular (⊥) to the stretching direction under different strains;

[0108] Figure 13 The composite blend film prepared in Example 1 of this invention, based on a blend ratio of 30:50:50 (mass ratio) of "compatibility agent", semiconductor conjugated polymer NDI-DTE and elastomer SEBS, and the fully flexible transistor of the control sample, are shown as the mobility variation trend curves under cyclic stretching parallel ( / / ) and perpendicular (⊥) to the stretching direction under 50% stress.

[0109] Figure 14Optical microscope and atomic force microscope images of the composite film of the "compatibility agent" prepared in Example 2 of the present invention, which is a blend of semiconductor conjugated polymer N2200 and elastomer SEBS, before and after the incorporation of the "compatibility agent".

[0110] Figure 15 The electrical properties of the semiconductor conjugated polymer N2200 and elastomer SEBS blend composite film prepared in Example 2 of this invention before and after the addition of a "composite agent" are shown.

[0111] Figure 16 The composite blend film (W / O) of semiconductor conjugated polymer N2200 and elastomer SEBS with a blend ratio of 30:50:50 (mass ratio) prepared in Example 2 of the present invention, and the composite blend film (W / O) of semiconductor N2200 and elastomer SEBS with a blend ratio of 50:50 (mass ratio) in Comparative Example 2, show the trend curves of the migration rate under different strains in the parallel and perpendicular stretching directions.

[0112] Figure 17 Optical microscope and atomic force microscope images of the composite film of the "compatibility agent" prepared in Example 3 of the present invention, which is a blend of semiconductor conjugated polymer PDPPTT and elastomer SEBS, before and after the incorporation of the "compatibility agent".

[0113] Figure 18 The electrical properties of the composite film of the "compatibility agent" prepared in Example 3 of this invention, which is a blend of semiconductor conjugated polymer PDPPTT and elastomer SEBS, are compared before and after the incorporation of the "compatibility agent".

[0114] Figure 19 The composite blend film (W / O) prepared in Example 3 of this invention, which is a blend of "compatibility agent" with semiconductor conjugated polymer N2200 and elastomer SEBS in a blend ratio of 30:50:50 (mass ratio), and the composite blend film (W / O) of semiconductor PDPPTT and elastomer SEBS in Comparative Example 3 in a blend ratio of 50:50 (mass ratio), show the trend curves of migration rate under different strains in the parallel and perpendicular stretching directions.

[0115] Figure 20 The mobility and on / off ratio of PNFFN-FDTE and hybrid films;

[0116] Figure 21 Optical micrographs of PNFFN-FDTE and hybrid thin films under tensile stress and crack initiation stress; Detailed Implementation

[0117] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0118] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0119] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0120] In the embodiments of this invention, anhydrous chlorobenzene, anhydrous N,N-dimethylformamide, and anhydrous dichloromethane refer to anhydrous and oxygen-free organic solvents that have been treated by a solvent treatment system. Furthermore, all solvents added during the experimental operation are placed in a glove box to strictly ensure that the experiment is conducted under anhydrous and oxygen-free conditions.

[0121] In this embodiment of the invention, the silicon wafer is modified as follows: First, it is sonicated with deionized water for 10 minutes (to remove water-soluble impurities from the silicon wafer surface). Then, approximately 15 mL of hydrogen peroxide and 35 mL of concentrated sulfuric acid are added, and the mixture is heated to boiling for approximately 15 minutes. Next, it is sonicated with deionized water for 10 minutes and isopropanol for 10 minutes. The cleaned silicon wafer is placed in a vacuum drying oven and heated to 90°C for 30 minutes to remove residual water molecules from the silicon wafer surface. Then, a small amount of n-octadecyltrichlorosilane (OTS) is added to the center of a petri dish, and the mixture is heated to 120°C. After 2 hours, it is cooled to room temperature, completing the modification. The modified silicon wafer is then sonicated with chloroform, n-hexane, and isopropanol for 10 minutes each to remove multiple layers of OTS deposited on the silicon wafer surface, ensuring that the OTS modification is a single layer. Finally, it is rapidly dried with nitrogen gas.

[0122] In this embodiment of the invention, a semiconductor thin film is prepared by spin coating in a glove box under a nitrogen atmosphere. The spin coater is rotated at 500 rpm for 5 seconds and then at 4000 rpm for 60 seconds to prepare the semiconductor thin film. After preparation, it is placed on a hot plate at 150°C for annealing for 30 minutes to further improve the deposition and increase the mobility.

[0123] In this embodiment of the invention, a metal mask is attached to a portion of the thin film, and 20 nm Au is deposited as the source and drain electrodes. Then, the field effect performance is characterized using an electrical testing system.

[0124] In this embodiment of the invention, the PDMS precursor (prepolymer) and Dow Corning SYLGARD 184 curing agent are mixed evenly at a mass ratio of 12:1, poured into a flat petri dish, cured at 80°C for 12 hours, and after complete curing, cut into strips for use as a flexible transfer substrate.

[0125] In this embodiment of the invention, PDMS is bonded to the surface of a semiconductor thin film, quickly peeled off, and stretched by 0%, 50%, 100%, 150%, and 200% respectively before being transferred to the surface of an unmodified silicon wafer.

[0126] In this embodiment of the invention, PDMS is bonded to the surface of a semiconductor thin film, quickly peeled off, stretched under 50% stress, cyclically stretched 500 times, a metal mask is attached, source and drain electrodes are deposited by vapor deposition, and electrical performance is tested.

[0127] Example 1

[0128] In this embodiment, the "compatibility agent" SEBS-g-PDPPTT is used, the blended polymer semiconductor is NDI-DTE, and the blended elastomer polymer is SEBS, with the following structure:

[0129]

[0130] The semiconductor fragment used, NDI-DTE, has a molecular weight of 50 kDa / mol; the SEBS used is H1221 (Asahi Kasei).

[0131] A blend film based on compatibilizer SEBS-g-PDPPTT, polymer semiconductor NDI-DTE, and SEBS was prepared by the following method:

[0132] I. Preparation of the "Compatibilizer" SEBS-g-PDPPTT

[0133] 1) End-capping of the target polymer under closed conditions: Weigh appropriate amounts of DPP39 (200 mg), TT (90.70 mg), catalyst tris(dibenzylacetone)dipalladium(O)[Pd2(dba)3] (2.8 mg), ligand tris(o-methylphenyl)phosphine P(o-tol)3 (3.4 mg), 3 ml of ultra-dry chlorobenzene, and 0.2 ml of LDMF into a 10 ml Schlenk reaction tube. Heat and stir at 115 °C for 1 h, then add end-capping agent 5-bromothiophene-2-methylamine (67.99 mg), and heat to 120 °C to react overnight.

[0134] 2) The reacted polymer was precipitated in a methanol solution containing a small amount of potassium fluoride, filtered, dried under nitrogen, and weighed to obtain the end-capped conjugated polymer PDPPTT-NH2; the structural formula is shown below:

[0135]

[0136] 3) Under an anhydrous and oxygen-free atmosphere, the capped conjugated polymer (40 mg) and SEBS-g-MAH (120 mg) were completely dissolved in 4 ml of anhydrous chlorobenzene, and then 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (11.16 mg) was added and heated at 60 °C for 13 h.

[0137] 4) After the reaction is complete, cool to room temperature, add the reaction solution dropwise into 400 mL of methanol solution to settle, and filter to obtain a dark green solid product.

[0138] 5) The product from 4) is subjected to Soxhlet extraction, and the remaining catalyst and other impurities are removed by methanol and acetone, and the desired product is extracted by n-hexane.

[0139] 7) The crude product is separated and purified by column chromatography. The nonpolar maleic anhydride-grafted styrene-ethylene / butene-styrene block copolymer (SEBS-g-MAH) can be eluted by column chromatography to separate the target product. The eluent used in the column chromatography is a mixed solvent of methanol and dichloromethane, with the polarity gradually increasing from pure petroleum ether to pure dichloromethane, and then to a mixed solvent of methanol and dichloromethane (methanol:dichloromethane = 1:3, v / v).

[0140] 8) The solution obtained in step 7) by passing methanol and dichloromethane (methanol:dichloromethane = 1:3, v / v) through the column was further dissolved in pure dichloromethane. During filtration, it is crucial to remove all silica gel (excess methanol will cause some silica gel in the column to dissolve in the column buffer). After further filtration to remove the silica gel, the resulting mixed solution was evaporated to dryness to obtain the pure graft copolymer "compatibilizer," namely SEBS-g-PDPPTT. The GPC:M ratio was determined by room temperature THF phase testing. n Molecular weight = 7.6 kDa, M w Molecular weight = 15.4 kDa, PDI = 2.20. 1 H NMR (400MHz): δ (ppm) 7.04 (d, 4H), 6.57 (d, 2H), 1.95 (d, 2H), 1.50 (s, 4H), 1.31 (s, 46H), 1.18–1.08 (m, 2H), 0.89 (q, 10H).

[0141] II. Preparation of Blend Thin Films

[0142] 9) Weigh 2 mg NDI-DTE, 2 mg SEBS, and 2 mg "composite agent" into pre-washed glass bottles, add 0.2 ml chlorobenzene to each, and finally prepare solutions with a concentration of 10 mg / mL. Take 0.15 ml NDI-DTE and 0.15 ml SEBS, along with different amounts of "composite agent" solutions, to prepare blended solutions with final "composite agent" ratios (the ratio of the mass of the "composite agent" to the total mass of the NDI-DTE semiconductor polymer and the SEBS elastomer) of 10%, 30%, and 60%. Under a nitrogen atmosphere, heat the solutions at 90°C on a hot plate for 1 hour with continuous stirring until completely dissolved. Use a spin coater at 2000 rpm on an OTS-modified silicon wafer for 60 seconds to prepare semiconductor thin films. After preparation, place the wafer on a hot plate at 200°C for annealing for 30 minutes to further improve deposition and increase mobility.

[0143] 10) The PDMS precursor (prepolymer) and Dow Corning SYLGARD 184 curing agent were mixed evenly at a mass ratio of 18:1, poured into a flat petri dish, and cured at 80°C for 12 hours. After complete curing, the mixture was cut into strips for use as flexible transfer substrates. The strips were then adhered to the surface of a semiconductor thin film using PDMS, quickly peeled off, and stretched by 0%, 50%, 100%, 150%, and 200% before being transferred to the surface of an unmodified silicon wafer. The morphological changes were observed using an optical microscope and an atomic force microscope.

[0144] III. Fabrication of Fully Stretchable Transistors

[0145] 11) Weigh SEBS1221 particles into a large beaker, add toluene solvent to prepare a viscous solution of 250 mg / ml, pour into a mold, and let stand to allow the solvent to slowly evaporate. Then, place it on a hot plate and heat at 80°C to remove residual solvent. After molding, cut to the required size. Weigh SEBS1052 particles into a glass bottle, add toluene solvent to prepare a solution of 70 mg / ml, filter with a filter head, and spin-coat it onto the surface of an OTS-modified silicon wafer at a speed of 1000 rpm. Then, place it in an oven for annealing at 100°C for 80 min. Pattern the OTS-modified silicon wafer, then spray CNT solution to prepare the gate, and place it on a hot plate at 90°C to remove water. Use an SEBS substrate to transfer the CNT gate, SEBS dielectric layer, and semiconductor layer layer layer by layer. Then, spray CNT source and drain electrodes onto the semiconductor surface to prepare a complete, fully stretchable transistor. Then, test the electrical properties of the blend film before and after adding the compatibilizer under stretching. The results show that the blended thin film with added compatibilizer exhibits excellent electrical and mechanical properties when used as a semiconductor layer in transistor devices. The mobility of the transistor device fabricated based on the blended thin film with added compatibilizer remains constant in the parallel direction under different strains within a 150% strain range, and the mobility does not decrease after film release. Furthermore, the transistor device with the blended thin film at 50% strain shows good stability in both the perpendicular and parallel stretching directions after 500 cyclic stretching cycles.

[0146] Comparative Example 1 (Comparative Example 1)

[0147] To more clearly demonstrate the improvement and optimization of device performance by the "composite agent", Comparative Example 1 and Example 1 were compared and analyzed. Comparative Example 1 did not add the "composite agent" and was the same as Example 1 in all other aspects such as preparation and testing.

[0148] Based on the conjugated polymer NDI-DTE, the elastomer polymer is SEBS, and the structure is as follows:

[0149]

[0150] The conjugated polymer used, NDI-DTE, has a molecular weight of 74 kDa / mol; the SEBS used is H1221 (Asahi Kasei).

[0151] Thin-film transistors based on conjugated polymer NDI-DTE and SEBS blends were fabricated using the following method:

[0152] I. Preparation of blended thin films

[0153] Weigh 2 mg of NDI-DTE and 2 mg of SEBS into pre-washed glass bottles, and add 0.2 ml of chlorobenzene to each, ultimately preparing solutions of 10 mg / mL. Prepare a blend solution using 0.15 ml of NDI-DTE and 0.15 ml of SEBS solution. Under a nitrogen atmosphere, heat the solution at 90°C for 1 hour with continuous stirring until completely dissolved. Spin coat the OTS-modified silicon wafer at 2000 rpm for 60 seconds to prepare a semiconductor thin film. After preparation, anneal the film on a 200°C hot stage for 30 minutes to further improve deposition and increase mobility.

[0154] II. Tensile Properties Study

[0155] The PDMS precursor (prepolymer) was mixed with Dow Corning SYLGARD 184 curing agent at a mass ratio of 18:1, poured into a flat petri dish, and cured at 80°C for 12 hours. After complete curing, it was cut into strips for use as flexible transfer substrates. The strips were then adhered to the surface of a semiconductor thin film using PDMS, quickly peeled off, and stretched by 0%, 50%, 100%, 150%, and 200% before being transferred to the surface of an unmodified silicon wafer. The morphological changes were observed using an optical microscope and an atomic force microscope.

[0156] III. Fabrication of Fully Stretchable Transistors

[0157] SEBS1221 particles were weighed into a large beaker, and toluene solvent was added to prepare a viscous solution of 250 mg / ml. This solution was poured into a mold and allowed to stand for slow solvent evaporation. Then, the mold was heated to 80°C on a hot plate to remove residual solvent. After molding, the mold was cut to the required size. SEBS1052 particles were weighed into a glass bottle, and toluene solvent was added to prepare a solution of 70 mg / ml. This solution was filtered and then spin-coated onto the surface of an OTS-modified silicon wafer at a speed of 1000 rpm. The wafer was then annealed in an oven at 100°C for 80 minutes. Patterning was performed on the OTS-modified silicon wafer, followed by spraying CNT solution to fabricate the gate layer. The wafer was then heated to 90°C on a hot plate to remove water. CNT gates, SEBS dielectric layers, and semiconductor layers were layer-by-layer transferred using a SEBS substrate. CNT source / drain electrodes were then sprayed onto the semiconductor surface to fabricate a complete, fully stretchable transistor. The electrical properties of the blend film before and after the addition of a compatibilizer under stretching were then tested. The results show that the blended thin film with added compatibilizer exhibits excellent electrical and mechanical properties when used as a semiconductor layer in transistor devices. The mobility of the transistor device fabricated based on the blended thin film with added compatibilizer remains constant in the parallel direction under different strains within a 150% strain range, and the mobility does not decrease after film release. Furthermore, the transistor device with the blended thin film at 50% strain shows good stability in both the perpendicular and parallel stretching directions after 500 cyclic stretching cycles.

[0158] Example 2

[0159] In this embodiment, the "compatibility agent" SEBS-g-PNBT is used, the blended polymer semiconductor is N2200, and the blended elastomer polymer is SEBS, with the following structure:

[0160]

[0161] The polymer semiconductor N2200 used has a molecular weight of 50 kDa / mol; the SEBS used is H1221 (from Asahi Kasei).

[0162] A blend film based on compatibilizer SEBS-g-PNBT, polymer semiconductor N2200, and SEBS was prepared by the following method:

[0163] I. Preparation of "Compatibilizer" SEBS-g-PNBT (compared to SEBS-g-PDPPTT, where DPP39 is replaced with NDI-C8C) 10 (TT replaced with BT)

[0164] 1) End-cap the target polymer under sealed conditions, weigh an appropriate amount of NDI-C8C 10 178 mg of BT (92.96 mg), 9 mg of BT catalyst tris(dibenzylacetone)dipalladium(0)[Pd2(dba)3] and 24.6 mg of ligand tris(o-methylphenyl)phosphine P(o-tol)3, 3 ml of ultra-dry chlorobenzene and 0.2 ml of LDMF were added to a 10 ml Schlenk reaction tube and heated and stirred at 115 °C for 1 h. Then, 72.60 mg of 5-bromothiophene-2-methylamine (72.60 mg) was added as a capping agent and the temperature was raised to 120 °C and reacted overnight.

[0165] 2) The reacted polymer was precipitated in a methanol solution containing a small amount of potassium fluoride, filtered, dried under nitrogen, and weighed to obtain the end-capped conjugated polymer PNBT-NH2; the structural formula is shown below:

[0166]

[0167] 3) Under an anhydrous and oxygen-free atmosphere, the capped conjugated polymer (40 mg) and SEBS-g-MAH (120 mg) were completely dissolved in 4 ml of anhydrous chlorobenzene, and then 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (11.16 mg) was added and heated at 60 °C for 13 h.

[0168] 4) After the reaction is complete, cool to room temperature, add the reaction solution dropwise into 400 mL of methanol solution to settle, and filter to obtain a dark green solid product.

[0169] 5) The product from 4) is subjected to Soxhlet extraction, and the remaining catalyst and other impurities are removed by methanol and acetone, and the desired product is extracted by n-hexane.

[0170] 7) The crude product is separated and purified by column chromatography. The nonpolar maleic anhydride-grafted styrene-ethylene / butene-styrene block copolymer (SEBS-g-MAH) can be eluted by column chromatography, thereby separating the target product. The eluent used in the column chromatography is a mixed solvent of methanol and dichloromethane, with the polarity gradually increasing from pure petroleum ether to pure dichloromethane, and then to a mixed solvent of methanol and dichloromethane (methanol:dichloromethane = 1:3, v / v).

[0171] 8) The solution obtained in step 7) by passing methanol and dichloromethane (methanol:dichloromethane = 1:3, v / v) through the column was further dissolved in pure dichloromethane. During filtration, it is crucial to remove all silica gel (excess methanol causes some silica gel in the column to dissolve in the column buffer). After further filtration to remove the silica gel, the resulting mixed solution was evaporated to dryness to obtain the pure graft copolymer "compatibilizer," namely SEBS-g-PNBT. The GPC:M ratio was determined by room temperature THF phase testing. n Molecular weight = 7.8 kDa, M w Molecular weight = 16.1 kDa, PDI = 2.10. 1 H NMR (400MHz): δ (ppm) 7.62 (d, 4H), 7.28 (m, 12H), 6.85 (d, 2H), 1.98 (d, 2H), 1.52 (s, 16H), 1.30 (s, 30H,), 1.10 (m, 4H,), 0.88 (q, 12H).

[0172] II. Preparation of Blend Thin Films

[0173] 9) Weigh 2 mg N2200, 2 mg SEBS, and 2 mg "compatibility agent" into pre-washed glass bottles, and add 0.2 ml of chlorobenzene to each, ultimately preparing solutions of 10 mg / mL. Take 0.15 ml of N2200, 0.15 ml of SEBS, and 0.09 ml of the "compatibility agent" solution to prepare a blending solution. Heat the solution on a hot plate at 90°C for 2 hours with continuous stirring until completely dissolved. Prepare a semiconductor thin film by spinning the OTS-modified silicon wafer at 2000 rpm for 60 seconds. After preparation, anneal the film on a hot plate at 200°C for 30 minutes to further improve the stacking properties.

[0174] III. Fabrication of Stretchable Transistors

[0175] 10) PDMS precursor (prepolymer) and Dow Corning SYLGARD 184 curing agent were mixed at a mass ratio of 15:1, poured into a flat petri dish, and cured at 80℃ for 12 hours. After complete curing, the mixture was cut into strips for use as flexible transfer substrates. PDMS was used to adhere the strips to the surface of semiconductor films, which were then quickly peeled off and stretched by 0%, 100%, and 200% before being transferred to unmodified silicon wafers. Morphological changes were observed using optical microscopy and atomic force microscopy. The results showed that the blend film with the added compatibilizer exhibited excellent electrical and mechanical properties when used as a semiconductor layer in transistor devices. The mobility of the transistor devices prepared based on the blend film with the added compatibilizer remained stable even after 200% stretching.

[0176] Comparative Example 2 (Comparative Example 2)

[0177] To more clearly demonstrate the improvement and optimization of device performance by the "compatibility agent", Comparative Example 2 and Example 2 were compared and analyzed. Comparative Example 2 did not add the "compatibility agent" and was the same as Example 2 in all other aspects such as preparation and testing.

[0178] In this comparative example, the conjugated polymer N2200 is used as the base polymer, and the blended elastomer polymer is SEBS, with the following structure:

[0179]

[0180] The conjugated polymer N2200 used has a molecular weight of 50 kDa / mol; SEBS uses H1221 (from Asahi Kasei).

[0181] The following method was used to prepare a blend film based on conjugated polymer N2200 and SEBS:

[0182] I. Preparation of blended thin films

[0183] 1) Weigh 5 mg N2200 and 5 mg SEBS into a pre-washed glass bottle, add 1 ml chlorobenzene, and finally prepare a solution containing 50% SEBS at a concentration of 10 mg / mL. Under atmospheric conditions, heat the solution on a hot plate at 75°C for 1 hour with constant stirring until completely dissolved. Spin coat the OTS-modified silicon wafer at 500 rpm for 5 seconds, then at 4000 rpm for 60 seconds to prepare a blended thin film. After preparation, anneal the film on a hot plate at 150°C for 30 minutes to further improve deposition and increase mobility. Then, deposit gold as the source and drain electrodes to construct an organic field-effect transistor.

[0184] II. Fabrication of Stretchable Transistors

[0185] 2) PDMS precursor (prepolymer) and Dow Corning SYLGARD 184 curing agent were mixed evenly at a mass ratio of 15:1, poured into a flat petri dish, and cured at 80℃ for 12 hours. After complete curing, the mixture was cut into strips for use as flexible transfer substrates. PDMS was used to adhere the strips to the surface of semiconductor films, which were then quickly peeled off and stretched by 0%, 100%, and 200% before being transferred to unmodified silicon wafers. Morphological changes were observed using optical and atomic force microscopy. The results showed that transistor devices prepared using the blend film without compatibilizer as the semiconductor layer exhibited significantly worse electrical and mechanical properties than those prepared with compatibilizer.

[0186] Example 3

[0187] In this embodiment, the "compatibility agent" SEBS-g-PDPPTT is used, the blended polymer semiconductor is PDPPTT, and the blended elastomer polymer is SEBS, with the following structure:

[0188]

[0189] The semiconductor fragment PDPPTT used has a molecular weight of 52 kDa / mol; the SEBS used is H1221 (Asahi Kasei).

[0190] A blend film of SEBS-g-PIVT, polymer semiconductor PDPPTT, and SEBS was prepared by the following method:

[0191] I. Preparation of the "Compatibilizer" SEBS-g-PIVT

[0192] 1) End-cap the target polymer under sealed conditions, weigh an appropriate amount of ISA-C 10 C 12 (191.75 mg), TVT (97.88 mg), catalyst tris(dibenzylacetone)dipalladium(0)[Pd2(dba)3] (2.8 mg), ligand tris(o-methylphenyl)phosphine P(o-tol)3 (3.4 mg), 3 ml of ultra-dry chlorobenzene and 0.2 ml of LDMF were placed in a 10 ml Schlenk reaction tube and heated and stirred at 115 °C for 1 h. Then, the end-capping agent 5-bromothiophene-2-methylamine (67.99 mg) was added, and the temperature was raised to 120 °C and reacted overnight.

[0193] 2) The reacted polymer was precipitated in a methanol solution containing a small amount of potassium fluoride, filtered, dried under nitrogen, and weighed to obtain the end-capped conjugated polymer PIVT-NH2; the structural formula is shown below:

[0194]

[0195] 3) Under an anhydrous and oxygen-free atmosphere, the capped conjugated polymer (40 mg) and SEBS-g-MAH (120 mg) were completely dissolved in 4 ml of anhydrous chlorobenzene, and then 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (11.16 mg) was added and heated at 60 °C for 13 h.

[0196] 4) After the reaction is complete, cool to room temperature, add the reaction solution dropwise into 400 mL of methanol solution to settle, and filter to obtain a dark green solid product.

[0197] 5) The product from step 4) is subjected to Soxhlet extraction. Residual catalyst and other impurities are removed using methanol and acetone, and the desired product is extracted using n-hexane.

[0198] 7) The crude product is separated and purified by column chromatography. The nonpolar maleic anhydride-grafted styrene-ethylene / butene-styrene block copolymer (SEBS-g-MAH) can be eluted by column chromatography, thereby separating the target product. The eluent used in the column chromatography is a mixed solvent of methanol and dichloromethane, with the polarity gradually increasing from pure petroleum ether to pure dichloromethane, and then to a mixed solvent of methanol and dichloromethane (methanol:dichloromethane = 1:3, v / v).

[0199] 8) The solution obtained in step 7) by passing methanol and dichloromethane (methanol:dichloromethane = 1:3, v / v) through the column was further dissolved in pure dichloromethane. During filtration, it is crucial to remove all silica gel (excess methanol causes some silica gel in the column to dissolve in the column buffer). After further filtration to remove the silica gel, the resulting mixed solution was evaporated to dryness to obtain the pure graft copolymer "compatibilizer," namely SEBS-g-PIVT. The GPC:M ratio was determined by room temperature THF phase testing. n Molecular weight = 8.0 kDa, M w Molecular weight = 16.2 kDa, PDI = 2.10. 1 H NMR (400MHz): δ (ppm) 7.80 (s, 2H), 7.45–7.35 (m, 12H), 7.00–6.80 (m, 8H), 1.90 (d, 2H), 1.50 (s, 20H), 1.30 (s, 40H), 1.10 (m, 6H), 0.88 (q, 18H).

[0200] II. Preparation of Blend Thin Films

[0201] 9) Weigh 2 mg of PDPPTT, 2 mg of SEBS, and 2 mg of "compatibilizer" into pre-washed glass bottles, and add 0.2 ml of chlorobenzene to each bottle to prepare solutions of 10 mg / mL. Prepare a blend solution by mixing 0.15 ml of PDPPTT, 0.15 ml of SEBS, and 0.09 ml of the "compatibilizer" solution. Under a nitrogen atmosphere, heat the solution at 90°C for 2 hours with continuous stirring until completely dissolved. Spin coat the OTS-modified silicon wafer at 2000 rpm for 60 seconds to prepare a semiconductor thin film. After preparation, anneal the film at 150°C for 30 minutes to further improve deposition and increase mobility.

[0202] III. Fabrication of Stretchable Transistors

[0203] 10) PDMS precursor (prepolymer) and Dow Corning SYLGARD 184 curing agent were mixed evenly at a mass ratio of 15:1, poured into a flat petri dish, and cured at 80℃ for 12 hours. After complete curing, the mixture was cut into strips for use as flexible transfer substrates. PDMS was used to adhere the strips to the surface of semiconductor films, which were then quickly peeled off and stretched by 0%, 100%, and 150%, respectively, before being transferred to unmodified silicon wafers. Morphological changes were observed using optical microscopy and atomic force microscopy. The results showed that the blend film with the added compatibilizer exhibited excellent electrical and mechanical properties when used as a semiconductor layer in transistor devices. The mobility of the transistor devices prepared based on the blend film with the added compatibilizer remained stable even under 200% stretching.

[0204] Comparative Example 3 (Comparative Example 3)

[0205] To more clearly demonstrate the improvement and optimization of device performance by the "compatibility agent", Comparative Example 3 and Example 3 were compared and analyzed. Comparative Example 3 did not add the "compatibility agent" and was the same as Example 3 in all other aspects such as preparation and testing.

[0206] Based on the conjugated polymer NDI-DTE, the elastomer polymer is SEBS, and the structure is as follows:

[0207]

[0208] The conjugated polymer used, NDI-DTE, has a molecular weight of 74 kDa / mol; the SEBS used is H1221 (Asahi Kasei).

[0209] Thin-film transistors based on conjugated polymer NDI-DTE and SEBS blends were fabricated using the following method:

[0210] I. Preparation of blended thin films

[0211] Weigh 2 mg of PDPPTT and 2 mg of SEBS into pre-washed glass bottles, and add 0.2 ml of chlorobenzene to each, ultimately preparing solutions of 10 mg / mL. Prepare a blend solution using 0.15 ml of PDPPTT and 0.15 ml of SEBS solution. Under a nitrogen atmosphere, heat the solution at 90°C for 1 hour with continuous stirring until completely dissolved. Spin coat the OTS-modified silicon wafer at 2000 rpm for 60 seconds to prepare a semiconductor thin film. After preparation, anneal the film at 150°C for 30 minutes to further improve deposition and increase mobility.

[0212] II. Tensile Properties Study

[0213] PDMS precursor (prepolymer) and Dow Corning SYLGARD 184 curing agent were mixed at a mass ratio of 15:1, poured into a flat petri dish, and cured at 80°C for 12 hours. After complete curing, the mixture was cut into strips for use as flexible transfer substrates. PDMS was then applied to the surface of a semiconductor thin film, quickly peeled off, and stretched by 0%, 50%, and 150% before being transferred to an unmodified silicon wafer. Morphological changes were observed using optical microscopy and atomic force microscopy. The results showed that transistor devices prepared using the blend film without compatibilizer as the semiconductor layer exhibited significantly worse electrical and mechanical properties than those prepared with compatibilizer.

[0214] Example 4

[0215] In this embodiment, the polymer semiconductor blend is based on the compatibilizer SEBS-g-PDPPTT, and the structure is as follows:

[0216]

[0217] I. Preparation of the "Compatibilizer" SEBS-g-PDPPTT

[0218] 1) End-capping of the target polymer under closed conditions: Weigh appropriate amounts of DPP39 (200 mg), TT (90.70 mg), catalyst tris(dibenzylacetone)dipalladium(O)[Pd2(dba)3] (2.8 mg), ligand tris(o-methylphenyl)phosphine P(o-tol)3 (3.4 mg), 3 ml of ultra-dry chlorobenzene, and 0.2 ml of LDMF into a 10 ml Schlenk reaction tube. Heat and stir at 115 °C for 1 h, then add end-capping agent 5-bromothiophene-2-methylamine (67.99 mg), and heat to 120 °C to react overnight.

[0219] 2) The reacted polymer was precipitated in a methanol solution containing a small amount of potassium fluoride, filtered, dried under nitrogen, and weighed to obtain the end-capped conjugated polymer PDPPTT-NH2; the structural formula is shown below:

[0220]

[0221] 3) Under an anhydrous and oxygen-free atmosphere, the capped conjugated polymer (40 mg) and SEBS-g-MAH (120 mg) were completely dissolved in 4 ml of anhydrous chlorobenzene, and then 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (11.16 mg) was added and heated at 60 °C for 13 h.

[0222] 4) After the reaction is complete, cool to room temperature, add the reaction solution dropwise into 400 mL of methanol solution to settle, and filter to obtain a dark green solid product.

[0223] 5) The product from 4) is subjected to Soxhlet extraction, and the remaining catalyst and other impurities are removed by methanol and acetone, and the desired product is extracted by n-hexane.

[0224] 7) The crude product is separated and purified by column chromatography. The nonpolar maleic anhydride-grafted styrene-ethylene / butene-styrene block copolymer (SEBS-g-MAH) can be eluted by column chromatography, thereby separating the target product. The eluent used in the column chromatography is a mixed solvent of methanol and dichloromethane, with the polarity gradually increasing from pure petroleum ether to pure dichloromethane, and then to a mixed solvent of methanol and dichloromethane (methanol:dichloromethane = 1:3, v / v).

[0225] 8) The solution obtained in step 7) by passing methanol and dichloromethane (methanol:dichloromethane = 1:3, v / v) through the column was further dissolved in pure dichloromethane. During filtration, it is crucial to remove all silica gel (excess methanol will cause some silica gel in the column to dissolve in the column buffer). After further filtration to remove the silica gel, the resulting mixed solution was evaporated to dryness to obtain the pure graft copolymer "compatibilizer," namely SEBS-g-PDPPTT. The GPC:M ratio was determined by room temperature THF phase testing. n Molecular weight = 7.6 kDa, M w Molecular weight = 15.4 kDa, PDI = 2.20. 1 H NMR (400MHz): δ (ppm) 7.04 (d, 4H), 6.57 (d, 2H), 1.95 (d, 2H), 1.50 (s, 4H), 1.31 (s, 46H), 1.18–1.08 (m, 2H), 0.89 (q, 10H).

[0226] II. Preparation of Blend Thin Films

[0227] 9) Weigh 2 mg of PNFFN-FDTE and 2 mg of "compatibilizer" into pre-washed glass bottles, add 0.2 ml of chlorobenzene to each, and finally prepare solutions of 10 mg / mL. Take 0.15 ml of PNFFN-FDTE and 0.15 ml of "compatibilizer" solution to prepare a blend solution. Under a nitrogen atmosphere, heat the solution at 90°C for 4 hours with constant stirring until completely dissolved. Spin coat the OTS-modified silicon wafer at 2000 rpm for 60 seconds to prepare a semiconductor thin film. After preparation, place it on a 200°C hot stage for annealing for 30 minutes to further improve deposition and increase mobility.

[0228] III. Fabrication of Stretchable Transistors

[0229] 10) The PDMS precursor (prepolymer) and Dow Corning SYLGARD 184 curing agent were mixed evenly at a mass ratio of 18:1, poured into a flat petri dish, and cured at 80°C for 12 hours. After complete curing, the mixture was cut into strips for use as flexible transfer substrates. The strips were then adhered to the surface of a semiconductor thin film using PDMS, quickly peeled off, and stretched by 0%, 50%, 100%, and 150% before being transferred to the surface of an unmodified silicon wafer. The morphological changes were observed using an optical microscope and an atomic force microscope.

[0230] The results show that direct blending of the graft copolymer SEBS-g-PDPPTT with the n-type polymer can improve the electrical properties of the polymer semiconductor. Pure PNFFN-FDTE films are bipolar materials with a very low on / off ratio (102). 2 -10 3 And the electron mobility is 0.188 cm⁻¹ 2 V -1 s -1 When SEBS-g-PDPPTT was added at a 1:1 mass ratio, the electron mobility increased to 0.284 cm⁻¹. 2 V -1 s -1 Furthermore, hole mobility decreased. When SEBS-g-PDPPTT was added at a mass ratio of 3:7, electron mobility decreased slightly to 0.180 cm⁻¹. 2 V -1 s -1 The hole mobility is further reduced, making the material a fully n-type material, and the on / off ratio is increased (10). 5 Furthermore, the blended film exhibits significantly improved tensile strength, remaining crack-free even after being stretched by 300%; upon release, the film shows no cracks or wrinkles, indicating that the blended film possesses excellent elasticity.

Claims

1. A graft copolymer "compatibilizer" comprising a semiconductor and an elastomer segment, the structure of which is shown in Formula 1: In the structure of Formula 1, the elastomer segment refers to a segment that exhibits sufficient chain mobility and elasticity at the molecular level, has weak intermolecular interaction, and has a reactive group for grafting. It includes but is not limited to maleic anhydride grafted ethylene-octene copolymer (POE-g-MAH), maleic anhydride grafted ethylene-propylene-diene rubber (EPDM-g-MAH), maleic anhydride grafted styrene-ethylene / butylene-styrene block copolymer (SEBS-g-MAH), etc. The different conjugated polymers synthesized by metal coupling reaction of the semiconductor fragments in structural formula 1, wherein A1 and A2 monomers are each independently selected from any structure of formula 2 and functionally similar structural units extended on the basis of this structure; wherein, In the structure of Formula 1, n is the number of A1-A2 repeating units. In the structure of Formula 1, Ar is a group that terminates the semiconductor. In the structure of Formula 1, the ratio of the semiconductor segment to the elastomer segment is 1:12, 1:6, 1:3, or 1:

1.

2. The graft copolymer "compatibilizer" comprising semiconductor and elastomeric segments according to claim 1, characterized in that: The semiconductor segment includes but is not limited to pyrrolodiketone conjugated polymers, isatin conjugated polymers, naphthalimide conjugated polymers, perylene conjugated polymers, thiophene conjugated polymers, carbazole conjugated polymers, benzothiadiazole conjugated polymers, fluorene conjugated polymers, etc. The Ar unit includes but is not limited to thiophene groups, thienothiophene groups, and bithiophene groups. In the structure of Formula 1, the ratio of the semiconductor segment to the elastomer segment is 1:12, 1:6, 1:3, or 1:

1. In Formula 2, each R is independently selected from any one of the following groups: substituted or unsubstituted alkyl, substituted or unsubstituted aryl, alkoxy, or alkylthio; preferably, each R is independently selected from any one of the following groups: methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, t-butyl, pentyl, n-hexyl, n-heptyl, n-octyl, i-octyl, n-nonyl, phenyl, fluorophenyl, bromophenyl, chlorophenyl, o-tolyl, p-tolyl, m-tolyl, o-ethylphenyl, p-ethylphenyl, m-ethylphenyl, o-i-propylphenyl, p-i-propylphenyl, m-i-propylphenyl, 1-naphthyl, 2-naphthyl, methylthio, ethylthio, propylthio, butylthio, pentylthio, hexylthio, heptylthio, octylthio, nonylthio, decylthio, methoxy, ethoxy, propoxy, butoxy, pentoxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, or decyloxy.

3. Grafted copolymer "compatibilizer" comprising semiconductor and elastomeric segments according to claim 1 or 2, characterized in that: The structure of the "compatibilizer" shown in Formula 1 is selected from any one of the following structures:

4. A method for preparing the block copolymer "compatibilizer" comprising a semiconductor and an elastomer segment according to any one of claims 1-3, comprising the following steps: S1, pre-polymerizing monomer A1 and monomer A2 by coupling reaction, and terminating by metal coupling reaction to synthesize a semiconductor polymer; the metal coupling reaction is Stille reaction or Suzuki reaction; S2, further polymerizing the terminated semiconductor polymer obtained in step S1 with the existing elastomer segment to obtain the target product "compatibilizer"; wherein The monomers A1 and A2 used in the S1 are each independently selected from any one of the monomer structures shown in Formula 2 as described in claim 1 and functionally similar structural units extended on the basis of the monomer structures.

5. The method for preparing the SEBS-g-PDPPTT as described in claim 4, the synthetic route (A) is shown as follows, comprising the following steps: (a1) under inert gas atmosphere, accurately weigh a specific amount of bromide monomer and tin monomer, meanwhile, weigh an appropriate amount of catalyst and ligand, then add them into the reaction solvent and mix well to prepare a mixed reaction solution; (a2) under anhydrous and anaerobic conditions, heat and stir the reaction. Then after a period of reaction, add the prepared end-capping agent solution into the reaction solution and continue to heat and stir the reaction; (a3) after the reaction is completed, cool to room temperature, add a methanol solution containing a small amount of potassium fluoride for quenching reaction (remove unreacted tin reagent), sedimentation, then collect the product and dry it under nitrogen environment. (a4) weigh the conjugated polymer obtained in step (3), catalyst and elastomer segment, and carry out ammonolysis reaction on the conjugated polymer obtained in step (a3) under inert atmosphere; (a5) add the reaction solution after the reaction into methanol solution for sedimentation, and then carry out Soxhlet extraction on the obtained reaction system in methanol, acetone and n-hexane in sequence, spin dry the solution extracted from n-hexane to obtain the crude product. Further, the method further comprises the step of separating and purifying the obtained crude product, specifically as follows: (a6) separate and purify the crude product by column chromatography, the non-polar maleic anhydride grafted styrene-ethylene / butylene-styrene block copolymer (SEBS-g-MAH) can be eluted by column chromatography, so as to separate the target product; (a7) elute the target product with methanol and dichloromethane in column chromatography. After spin drying, redissolve it with dichloromethane, filter to remove silica gel, then spin dry the obtained solution to obtain the pure polymer "compatibilizer". Further, in the step (a1), the bromide monomer is selected from 3,6-bis(5-bromothiophene-2-yl)-2,5-bis(2-decyltetradecyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (synthesized according to the existing literature); and the tin monomer is selected from 2,5-bis(trimethylstannyl)thieno[3,2-b]thiophene; The molar ratio of the bromide monomer and the tin monomer can be 1:1.1 (the bromide monomer is slightly less than the tin monomer), so as to ensure that both ends of the polymer are tin reagents which can react with the end-capping agent; The catalyst and ligand unit are tris(dibenzylideneacetone)dipalladium(0) [Pd2(dba)3] and tri(o-tolyl)phosphine P(o-tol)3, respectively. The amount of the catalyst is 1-5% of the molar amount of the tin monomer in the reaction system, and the molar ratio of the amount of the ligand to the amount of the catalyst is 2:1-8:

1. The reaction solvent can be one of chlorobenzene, toluene, xylene and the like, preferably, chlorobenzene is selected as the reaction solvent. Further, in step (a2), the reaction temperature of the reaction is 115-120℃, and the reaction is carried out for 1 hour, and then a capping agent is added. Further, the end-capping compound added in step (a4) has a structural formula of The molar ratio of the end-capping compound to the conjugated polymer is 1:1-1:1.

05. Further, in step (a2), the quenching reaction is stirred for 1-3 hours, and then Soxhlet extraction is carried out with methanol and acetone for 8-14 hours. In step (a4), the reaction is carried out in a reaction solvent, and the reaction solvent can be chlorobenzene, toluene, or xylene, and preferably, chlorobenzene is selected as the reaction solvent. In step (a4), the molar amount of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide catalyst added is 1-2 times the acid anhydride content in the maleic anhydride grafted styrene-ethylene / butylene-styrene block copolymer (SEBS-g-MAH). Further, in step (a4), preferably, heating is carried out at 60℃ for 13 hours. Further, in step (a5), a small amount of methanol is added to precipitate the "compatibilizer" polymerized. Further, in step (a5), Soxhlet extraction is carried out, and the remaining catalyst and other impurities are removed by methanol and acetone, and the desired product is extracted by n-hexane. Further, in step (a6), the eluent used in column chromatography is a mixed solvent of methanol and dichloromethane, and the polarity gradually increases from pure petroleum ether to pure dichloromethane, and then to a mixed solvent of methanol and dichloromethane (methanol:dichloromethane = 1:3, v / v). Further, in step (a6), the solution passed through the mixed solvent of methanol and dichloromethane (methanol:dichloromethane = 1:3, v / v) is further dissolved by dichloromethane, and it is necessary to remove the silica gel completely during the filtration process (excessive methanol causes part of the silica gel in the column to dissolve in the over-column liquid).

6. Use of the graft copolymer "compatibilizer" comprising a semiconductor and an elastomer segment according to any one of claims 1-3 in the preparation of a flexible and stretchable field effect transistor.

7. A flexible and stretchable field effect transistor, wherein the active layer comprises the graft copolymer "compatibilizer" comprising a semiconductor and an elastomer segment according to any one of claims 1-3. Further, the active layer further comprises a polymer semiconductor and an elastomer or a polymer semiconductor; Preferably, the amount of "compatibilizer" added is 0.01%-50% of the total mass of the polymer semiconductor and the elastomer, and preferably 30%. Or the "compatibilizer" is directly added to the semiconductor polymer solution, and the ratio of the semiconductor polymer to the "compatibilizer" is 1:0, 1:1, 3:7, and preferably 3:

7.

8. A method for preparing the flexible and stretchable field effect transistor according to claim 7, comprising the following steps: (a) first adding the graft copolymer "compatibilizer" comprising a semiconductor and an elastomer segment according to any one of claims 1-3 to a mixed solution of a polymer semiconductor and an elastomer, and preparing a blended semiconductor thin film on a substrate by a spin coating method; or directly adding the "compatibilizer" to a polymer semiconductor, and preparing a blended semiconductor thin film on a substrate by a spin coating method. (b) preparing an elastic substrate for transferring the blended semiconductor thin film; (c) transferring the blended semiconductor thin film using an elastic substrate and stretching different forces and then transferring to a target substrate again, evaporating source-drain electrodes, obtaining the flexible and stretchable field effect transistor.

9. The method of claim 8, wherein: In the step (a), the polymer semiconductor and the elastomer are dissolved in chlorobenzene and heated to obtain a mixed solution; or the polymer semiconductor is directly dissolved in chlorobenzene and heated. In the step (a), the polymer semiconductor is NDI-DTE molecule and the elastomer is SEBS. NDI-DTE and SEBS are physically blended in a certain proportion, and the mass ratio of NDI-DTE:SEBS is 1:0, 3:1, 1:1, 3:7, and 1:9, respectively. Preferably, based on the blending ratio of NDI-DTE and SEBS being 1:1, the "compatibilizer" (SEBS-g-PDPPTT) is added, and the mass of the "compatibilizer" is 0.1%-30% of the total mass of NDI-DTE semiconductor polymer and SEBS elastomer; or the polymer semiconductor is PNFFN-FDTE, which is directly mixed with the "compatibilizer", and the blending ratio of FNFFN-FDTE: "compatibilizer" is 1:0, 1:1, and 3:7, preferably 3:

7. In the step (a), the solution spin coating speed is 1500 rpm, and the remaining rotation speed is 4000 rpm; the selected substrate is an OTS modified silicon wafer; the evaporated metal is gold as the source-drain electrode. In the step (b), the elastic substrate is PDMS, and its preparation includes stirring PDMS precursor and Dow Corning SYLGARD184 curing agent uniformly at a mass ratio of 12:1, pouring into a glass culture dish, curing at 80°C for 12h, and cutting into strips for standby; In the step (c), the PDMS substrate is used to adhere to the spin-coated prepared thin film, quickly peeled off, and then placed on a stretching device, and different forces are stretched, including 0%, 25%, 50%, 75%, 100%, 150%, and 300%.

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