A method for fabricating stretchable polymer nanowire transistors and optoelectronic applications

Abstract

The application provides a preparation method of a stretchable polymer nanowire transistor and photoelectric application thereof, and belongs to the field of stretchable electronic devices. The transistor adopts a bottom gate top contact or bottom gate bottom contact structure, is composed of a stretchable substrate, a gate, an insulating layer, a semiconductor layer and source-drain electrodes, and the semiconductor layer is a polymer nanowire prepared by coaxial fluid jet printing of a conjugated polymer and elastomer polymer blended solution. The method realizes preparation of nanowires with high stretchability and high orientation, so that the semiconductor layer has excellent stretchability and electrical properties. Through horizontal and vertical integration, a stretchable complementary inverter and a visual self-adaptive device are constructed, and the advantages of multifunctional integration are exhibited. The application has wide application prospects in the development of miniaturized, highly integrated wearable electronic devices and multifunctional neural interfaces.

Description

Technical Field

[0001] This invention belongs to the field of stretchable electronic device technology, specifically relating to a method for preparing and applying stretchable polymer semiconductor nanowires with both excellent electrical and mechanical properties. This invention utilizes polymer nanowires to prepare stretchable field-effect transistors with high stretchability and excellent electrical properties, and further realizes stretchable complementary inverters and visual adaptive function simulation applications. Background Technology

[0002] Stretchable electronic devices, as an emerging electronic application product, break through the limitations of traditional planar rigid circuits, further broadening the application fields of electronics and driving significant innovations in engineering and technology. Compared to traditional electronic devices, stretchable organic electronic devices, due to their flexibility, bendability, and simple structure, can adapt to irregular and soft objects and seamlessly connect with human skin. Therefore, they show great potential in many areas where traditional rigid electronic products cannot be implemented, such as long-term real-time medical monitoring, prosthetics, and virtual reality (VR). As one of the important basic active components in stretchable electronic circuits, stretchable organic field-effect transistors play a key role in sensor addressing, signal readout, and amplification in flexible electronic products. In the future, these devices will further develop towards high performance and multifunctionality, integrating more sensing, control, and feedback functions to achieve deeper interaction with the human body and environment, driving revolutionary progress in fields such as medical health, bionics, and brain-computer interfaces. To realize these applications, high-performance stretchable semiconductors and multifunctional device integration are required. However, current research mainly focuses on the development of stretchable p-type semiconductors, lacking high-performance stretchable n-type semiconductors. Their overall mobility is low, and the variety of materials is limited, severely restricting the potential of stretchable electronics. Furthermore, since existing devices cannot achieve multifunctional applications with simple structures, multifunctional devices often rely on complex structural designs and multilayer constructions. Therefore, there is an urgent need to develop novel device architectures to simplify structures and facilitate multifunctional integration.

[0003] Polymer semiconductors, characterized by low elastic modulus, high flexibility, and high stretchability, are crucial components of skin-inspired soft electronics. From a molecular design perspective, high performance and high stretchability in polymer semiconductors are often contradictory and difficult to achieve simultaneously. Current research on improving the mechanical properties of polymer semiconductors mainly falls into three categories: (i) enhancing molecular stretchability by incorporating modified side chains or non-conjugated flexible groups into semiconductor polymer chains (J. Am.Chem. Soc. 2022, 144, 4699−4715); (ii) increasing polymer chain stretchability by incorporating semiconductor polymer nanofiber networks into stretchable elastomers through nanoconfining (Science. 2017, 355, 59–64); and (iii) depositing semiconductor polymer nanowires onto pre-strained elastic substrates to generate strain-designed geometries (Adv. Mater. 2018, 30, 1704401). While these methods can improve the stretchability of conjugated polymers to some extent, they significantly impair carrier mobility. The fundamental problem lies in the fact that intrinsically stretchable polymers, due to their flexible side-chain / main-chain structures or the disordered structures formed by incorporated elastomers, exhibit low carrier mobility. Polymers with high mobility require rigid π-π conjugated molecular structures and ordered stacked molecular chain structures. However, rigid structures severely compromise electrical properties under significant mechanical deformation. Therefore, current research focuses on simultaneously achieving high stretchability and excellent electrical properties in organic semiconductors, and optimizing them according to different application requirements to promote the practical application of stretchable multifunctional electronic devices.

[0004] Given the aforementioned challenges, stretchable, highly crystalline semiconductor nanowires are more advantageous for charge carrier transport in active channels compared to randomly dispersed nanofibers in thin film form. Therefore, fabricating stretchable polymer nanowires with high crystallinity and ordered structures (from single-chain conformation to macroscopic orientation) is essential for the miniaturization and highly integrated production of wearable electronic devices. Summary of the Invention

[0005] This invention aims to provide a method for fabricating a stretchable polymer nanowire transistor and its optoelectronic applications. By employing electrofluidic printing technology, this invention achieves the fabrication of highly stretchable and highly oriented polymer nanowires, enabling the polymer semiconductor functional layer to possess both high stretchability and excellent electrical properties. Ultimately, a transistor with high stretchability and high performance is successfully fabricated, and analog applications with stretchable complementary inverters and visual adaptive functions are realized.

[0006] This invention first provides a stretchable polymer nanowire transistor, which is a bottom-gate top contact or bottom-gate bottom contact structure, including a stretchable substrate, a stretchable gate, a stretchable insulating layer, a stretchable semiconductor layer, and stretchable source and drain electrodes; The stretchable semiconductor layer is a polymer nanowire; the polymer nanowire is prepared by coaxial electrohydrodynamic printing from a blend solution of conjugated polymer and elastomer polymer.

[0007] In the aforementioned transistor, the conjugated polymer is a naphthalimide (NDI) polymer, an isoindigo (IID) polymer, a thiophene polymer, or a pyrrolopyrrole dione (DPP) polymer; The elastomer polymer is any one of unsaturated rubber, saturated rubber, and thermoplastic elastomer.

[0008] In the aforementioned transistor, the conjugated polymer is selected from poly-3,6-dithiophene-2-yl-2,5-bis(2-decyltetradecyl)-pyrrolo[3,4-c]pyrrolo-1,4-dione-alt-thiophenevinylthiophene-2,5-diyl (PDVT-10), polyindodithiophene-benzothiadiazole (IDT-BT), poly(fluorinated isoindigo trifluoromethylthiophene vinylthiophene) (FIID-CF3TVT), poly{[N,N9-bis(2-octyl) The following are all of the following: [2,5-bis(2-octyldodecyl)-naphthyl-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,59-(2,29-anthiophene)} (N2200), poly[2,5-bis(2-octyldodecyl)-3,6-bis(thiophene-2-yl)dionepyrrole[3,4-c]pyrrole-1,4-dione-alt-thiophene[3,2-b]thiophene} (DPPT-TT), and poly(3-hexylthiophene) (P3HT); The elastomer polymer is selected from any one of natural rubber (NR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), butyl rubber (IIR), ethylene propylene rubber (EPR), polydimethylsiloxane (PDMS), polyether ester elastomer (TPEE), polyacrylate rubber (ABR), hydrogenated styrene-butadiene block copolymer (SEBS), and polyurethane elastomer (PU).

[0009] Specifically, the hydrogenated styrene-butadiene block copolymer is a hydrogenated styrene-butadiene-styrene block copolymer elastomer; more specifically, it can be SEBS-H1221 or SEBS-H1052.

[0010] In the aforementioned transistor, the mass ratio of the conjugated polymer to the elastomeric polymer is 1:9 to 9:1; preferably 3:7 to 5:5. The solvent for the blend solution of the conjugated polymer and the elastomer polymer is any one of chlorobenzene, dichlorobenzene, xylene, and toluene; In the blend solution of the conjugated polymer and the elastomer polymer, the concentration of the polymer is 3 mg / mL to 20 mg / mL; specifically, it can be 10 mg / mL.

[0011] In the aforementioned transistor, the thickness of the stretchable substrate is 500 µm-2 mm, specifically 1.2-1.5 mm; The thickness of the stretchable gate is 50-100 nm, specifically 60-80 nm; The thickness of the stretchable insulating layer is 1.2 µm-2.5 µm, specifically 1.5 µm; The thickness of the stretchable semiconductor layer is 30 nm-500 nm, specifically 30-200 nm or 100 nm-200 nm; The thickness of the stretchable source and drain electrodes is 50-100nm, specifically 50-80nm; Both the stretchable substrate and the stretchable insulating layer are made of elastomeric polymers; Specifically, the elastomer polymer is any one of unsaturated rubber, saturated rubber, and thermoplastic elastomers; specifically, it can be selected from any one of natural rubber (NR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), butyl rubber (IIR), ethylene propylene rubber (EPR), polydimethylsiloxane (PDMS), polyether ester elastomer (TPEE), polyacrylate rubber (ABR), hydrogenated styrene-butadiene block copolymer (SEBS), hydrogenated styrene-butadiene-styrene block copolymer elastomer, and polyurethane elastomer (PU).

[0012] The stretchable gate, the stretchable source, and the drain electrode are all made of intrinsically stretchable conductive material. The intrinsically stretchable conductive material is a two-dimensional conductive material (such as graphene (G)), metal nanowires (such as silver nanowires (Ag NWs), gold nanowires (Au NWs) or copper nanowires (Cu NWs)), liquid metal (such as gallium indium alloy (EGaIn)), conductive polymer (such as poly(3,4-ethylenedioxythiophene)-polyvinylbenzenesulfonic acid (PEDOT:PSS)) or metallic single-walled carbon nanotubes (such as P1-SWNT, P2-SWNT, P3-SWNT, P5-SWNT, P7-SWNT, P8-SWNT or P9-SWNT); The conductivity of the stretchable gate and stretchable source and drain electrodes is 1×10⁻⁶. 3 -5×10 5 S·cm -1 .

[0013] In the aforementioned transistor, during the preparation of the polymer nanowires, the external liquid is polydimethylsiloxane (PDMS), silicone oil, hydrogenated styrene-butadiene block copolymer (SEBS), or polymethyl methacrylate (PMMA); the internal liquid is a blend solution of the conjugated polymer and the elastomer polymer; the applied voltage is 2-10 kV (specifically 5 kV or 5.5 kV); the internal liquid supply flow rate is 200-2000 nL / min (specifically 600 nL / min, 800 nL / min, or 1000 nL / min); the external liquid supply flow rate is 1-20 µL / min (specifically 4 µL / min); the substrate migration rate is 1-800 mm / s (specifically 300 mm / s or 400 mm / s); and annealing is performed at 80-220 °C after printing.

[0014] Specifically, the annealing time is 10-120 min.

[0015] More specifically, the annealing is performed at 80 °C for 30 min.

[0016] The polymer nanowires are printed on a substrate with a sacrificial layer.

[0017] In the preparation of the polymer nanowires described above, after annealing, the prepared sample was placed in isopropanol at 60 °C for 5 min, dried with nitrogen, and then placed on a hot stage at 150 °C for 30 min.

[0018] The present invention further provides a method for fabricating the above-mentioned transistor, comprising the following steps: (1) Prepare a sacrificial layer on the substrate; (2) A stretchable substrate is prepared on a substrate with a precipitated sacrificial layer; (3) A stretchable gate is fabricated on a substrate with a precipitated sacrificial layer; (4) Prepare a stretchable insulating layer on the substrate of the precipitated sacrificial layer; (5) A stretchable semiconductor layer is prepared on a substrate with a precipitated sacrificial layer by coaxial electrohydrodynamic printing; (6) Fabricate stretchable source and drain electrodes on a substrate with a precipitated sacrificial layer; (7) Gently peel the stretchable substrate prepared in step (2) off the substrate of the precipitated sacrificial layer, and then attach the stretchable substrate to the stretchable gate prepared in step (3) from the other side to achieve complete coverage and attachment to the stretchable gate. Then gently peel the fully attached stretchable substrate and stretchable gate off the substrate to complete the stretchable gate transfer. (8) Transfer the stretchable insulating layer, stretchable semiconductor layer and stretchable source and drain electrodes onto the stretchable substrate in the same way as in step (7) to obtain the transistor.

[0019] In the above preparation method, in step (7), the bonding process is carried out in a vacuum oven; specifically, the temperature of the vacuum oven is 60 ℃ and the vacuum degree is 0.1 Pascal; the heating is carried out in the vacuum oven for 20 min; In the above preparation method, the substrate is a glass sheet, silicon wafer, SiO2-Si silicon substrate, PET plastic, or quartz, etc. The sacrificial layer can be prepared by depositing a self-assembled molecular layer; The substrate is treated as follows before the preparation of the sacrificial layer: it is ultrasonically cleaned sequentially with deionized water, acetone and ethanol, dried with a nitrogen gun, and then subjected to ozonolysis (UVO or O3plasma) to obtain a surface hydroxylated substrate; specifically, the ultrasonic cleaning power is 20-100W and the time is 5-15 min.

[0020] The sacrificial layer can be prepared using either a gas-phase modification method or a liquid-phase modification method. Specifically, the gas-phase modification method involves subjecting the substrate and any one of phenyltrichlorosilane, octadecyltrimethoxysilane, octadecyltrichlorosilane, and octadecyltrichlorosilane to vacuum heating at a vacuum level of 0.1 Pa, a heating temperature of 50-150 °C (specifically 120 °C), and a heating time of 1-3 h. The liquid-phase modification method includes the following steps: immersing the substrate in a modification material solution, wherein the volume ratio of octadecyltrimethoxysilane, octadecyltrichlorosilane, octadecyltrichlorosilane, or phenyltrichlorosilane to the solvent n-hexane, n-heptane, isohexane, or cyclohexane is 1:200-1:1000, and the immersion time is 0.1-3 h.

[0021] In the above preparation method, the stretchable substrate and the stretchable insulating layer are prepared by drop coating, spin coating, blade coating, or film stretching; the solvent used is toluene, xylene, chlorobenzene, dichlorobenzene, chloroform, dichloromethane, tetrahydrofuran, N,N-dimethylformamide (DMF), n-hexane, or cyclohexane; the concentration of the solution used for the stretchable substrate is 150-250 mg / mL; the concentration of the solution used for the stretchable insulating layer is 50-85 mg / mL. The stretchable gate and stretchable source and drain electrodes are prepared by a spray coating process. In one embodiment of the present invention, the spraying solution is a carbon nanotube solution, and the solvent is at least one selected from ethanol, water, chlorobenzene, isopropanol and N-methylpyrrolidone; the concentration of the carbon nanotube solution is 0.1-1 mg / mL; the distance between the spray gun and the substrate is 10-20 cm, the substrate temperature is 50-150 ℃, and the spray gun speed is 0.2-3 mL / min; After spraying, perform heat annealing to evaporate the solvent. The annealing temperature is 80-130 ℃ and the time is 5-20 min.

[0022] The present invention also provides a polymer nanowire prepared by coaxial electrohydrodynamic printing from a blend solution of a conjugated polymer and an elastomer polymer.

[0023] In the above-mentioned polymer nanowires, the conjugated polymer is a naphthalimide (NDI) polymer, an isoindigo (IID) polymer, a thiophene polymer, or a pyrrolopyrrole dione (DPP) polymer. The elastomer polymer is any one of unsaturated rubber, saturated rubber, and thermoplastic elastomer; The mass ratio of the conjugated polymer to the elastomer polymer is 1:9 to 9:1; preferably 3:7 to 5:5. The solvent for the blend solution of the conjugated polymer and the elastomer polymer is any one of chlorobenzene, dichlorobenzene, xylene, and toluene; In the conjugated polymer and elastomer polymer blend solution, the polymer concentration is 3 mg / mL-20 mg / mL; In the preparation of the polymer nanowires, the external liquid is polydimethylsiloxane, silicone oil, hydrogenated styrene-butadiene block copolymer, or polymethyl methacrylate; the internal liquid is a blend solution of the conjugated polymer and the elastomer polymer; the applied voltage is 2-10 kV; the internal liquid supply flow rate is 200-2000 nL / min; the external liquid supply flow rate is 1-20 µL / min; the substrate migration speed is 1-800 mm / s; and the nanowires are annealed at 80-220 °C after printing.

[0024] The polymer nanowires can be effectively controlled by changing any one of the following: the concentration of the mixed solution, the voltage, and the annealing temperature.

[0025] This invention also provides the application of polymer nanowires in the fabrication of stretchable complementary inverters; or Application of polymer nanowires in the fabrication of stretchable optical adaptive devices.

[0026] Finally, the present invention provides a stretchable complementary inverter comprising the aforementioned polymer nanowires.

[0027] A stretchable optical adaptive device comprising the aforementioned polymer nanowires.

[0028] The present invention has the following beneficial effects: This invention proposes a fabrication strategy for stretchable polymer nanowires. Specifically, it utilizes electrofluidic printing technology to achieve high-precision, non-destructive patterning of stretchable polymer semiconductors, while also supporting large-area integration. Based on this strategy, stretchable polymer nanowire-based transistors were successfully fabricated and applied to the simulation of stretchable complementary inverters and visual adaptive functions. Stretchable devices fabricated using stretchable polymer nanowires possess significant advantages in high stretchability, high performance, and multifunctional integration, providing a crucial impetus for the future development of brain-computer interfaces, medical detection, and multifunctional soft robots. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the stretchable polymer nanowire transistor structure of the present invention; Figure 1 (a) is the bottom gate top contact structure; (b) is the bottom gate bottom contact structure.

[0030] Figure 2 This is the main fabrication process of the stretchable polymer nanowire transistor of the present invention.

[0031] Figure 3 Optical microscope images of the polymer nanowires prepared in Example 1 and their stretched state are shown; wherein, Figure 3 (a) is an optical microscope image of the polymer nanowire, (b) is the stretched state in the parallel direction, and (c) is the stretched state in the perpendicular direction.

[0032] Figure 4 The ultraviolet-visible absorption spectrum, atomic force microscopy image, and grazing incidence X-ray diffraction pattern of the polymer nanowires prepared in this invention are shown below; wherein, Figure 4 In the image, (a) shows the UV-Vis absorption spectra of the polymer nanowires or films prepared in Example 1, Comparative Example 3 and Comparative Example 1, (b) shows the atomic force microscope image of the polymer nanowires prepared in Example 1, and (c) shows the grazing incidence X-ray diffraction pattern of the polymer nanowires prepared in Example 1.

[0033] Figure 5 The transfer characteristic curves of the stretchable polymer nanowire transistor prepared in Example 1 under different tensile deformations in the parallel channel direction and the perpendicular channel direction are shown; wherein, Figure 5 In the diagram, (a) represents the direction parallel to the channel, and (b) represents the direction perpendicular to the channel.

[0034] Figure 6The figures show the voltage-transfer characteristic curves of a stretchable nanowire inverter based on polymer nanowires and the current-time curves of a stretchable nanowire adaptive device; among them, Figure 6 In the figure, (a) is the voltage-transfer characteristic curve of the inverter, and (b) is the current-time curve of the adaptive device. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to specific embodiments. The embodiments given are only for illustrating the present invention and are not intended to limit the scope of the present invention.

[0036] Unless otherwise specified, the experimental methods described in the following examples are conventional methods.

[0037] In the quantitative experiments in the following examples, three replicate experiments were set up, and the average value of the results was taken.

[0038] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0039] The hydrogenated styrene-butadiene-styrene block copolymer elastomers SEBS-H1221 (80% EB) and SEBS-H1052 used in the following examples were purchased from Asahi Kasei, Japan.

[0040] The single-walled carbon nanotubes P3-SWNT were purchased from Carbon Solutions, Inc. (CSI) (USA).

[0041] Poly(fluorinated isoindigo trifluoromethylthiophene vinylthiophene) (FIID-CF3TVT) was synthesized in the laboratory: the specific synthesis route is described in Example 3 of Chinese Patent 202010098740.9.

[0042] The structure of FIID-CF3TVT is as follows:

[0043] Wherein, R is 4-decyltetradecyl, and n is a natural number from 13 to 20.

[0044] Polyindobisthiophene-benzothiadiazole (IDT-BT), molecular weight 10w, was purchased from Ruixun Technology Co., Ltd. (Shenzhen).

[0045] This invention provides a stretchable polymer nanowire-based transistor, which can be used as follows: Figure 1 The bottom grid top contact shown ( Figure 1 a) and bottom contact of the grid ( Figure 1b) Two device structures include a stretchable substrate, a stretchable gate electrode, a stretchable insulating layer, a stretchable semiconductor layer, a stretchable source, and a drain electrode; the stretchable semiconductor layer is a polymer nanowire.

[0046] The polymer nanowires are fabricated using coaxial electrohydraulic inkjet printing. An applied electric field causes the electric field force generated by the charges in the polymer liquid to drive the liquid to focus and flow inwards. Combined with the viscous shear force of the external liquid, the polymer liquid forms a stable conical jet, thus forming uniform nanowires on the substrate. The resulting nanowires exhibit high orientation and excellent stretchability, and the transistors fabricated from them possess excellent electrical and mechanical properties. Horizontal or vertical integration of two semiconductor nanowires with different polarities (P / N) produces stretchable nanowire functional devices with excellent device performance.

[0047] Example 1 (1) The silicon wafer and glass substrate were ultrasonically cleaned sequentially with deionized water, acetone and ethanol (ultrasonic time 10 min, power 30 W), dried with nitrogen gun, and then O3plasma treatment was performed on the substrate for 10 min at 100% power to obtain a clean substrate with surface hydroxylation treatment.

[0048] (2) A sacrificial layer was deposited on a clean substrate by gas phase precipitation. The specific steps are as follows: a small amount of octadecyltrichlorosilane (OTS) was dropped into a container, heated at 120 °C for 3 h under vacuum conditions with a vacuum degree of 0.1 Pa, and cooled to room temperature to complete the preparation.

[0049] (3) SEBS-H1221 solution (200 mg / mL, toluene solvent) was uniformly dripped onto the glass substrate with the precipitated sacrificial layer using a syringe. Then the substrate was placed on a hot table and heated at 40 °C for 6 h to remove the solvent, thus obtaining a stretchable substrate with a thickness of 1.2-1.5 mm.

[0050] (4) Place the silicon wafer substrate with the precipitated sacrificial layer on an 80 ℃ hot stage. Take 2 mL of P3-SWNT solution (0.1 mg / mL, solvent is isopropanol) and place it in the volume chamber of the spray gun. Spray the sacrificial layer onto the silicon wafer vertically and uniformly at a height of 10 cm from the substrate. Then anneal at 80 ℃ for 5 min to obtain a stretchable gate with a thickness of 60-80 nm. The conductivity of the obtained stretchable gate is 2×10 5 S·cm -1 .

[0051] (5) Place the silicon wafer substrate with the precipitated sacrificial layer at the center of the spin coater rotor, and use a pipette to take 300 uL of SEBS-H1052 solution (75 mg / mL, cyclohexane solvent) and drop it evenly onto the substrate. Start the spin coater, rotate at 1000 rpm, spin coat for 1 min, and then place it on a hot stage at 90 ℃ for 30 min; a stretchable insulating layer with a thickness of 1.5 μm is obtained.

[0052] (6) Place the silicon wafer substrate with the precipitated sacrificial layer on the sample stage of the electro-inkjet printer. Take 100 μL of FIID-CF3TVT / SEBS-H1221 chlorobenzene solution (10 mg / mL, FIID-CF3TVT / SEBS mass ratio of 3:7) into a syringe for the internal liquid and 1 mL of silicone oil into a 2.5 mL syringe for the external liquid. Apply a voltage of 5 kV, a supply flow rate of 800 nL / min for the internal liquid and 4 μL / min for the external liquid, and a substrate movement speed of 300 mm / s. Print the required number of nanowires, and then anneal at 80 °C for 30 min. Then place it in isopropanol at 60 °C for 5 min, dry it with a nitrogen gun, and finally place it on a hot stage at 150 °C for 30 min to obtain polymer nanowires, which are stretchable semiconductor layers with a thickness of 30-200 nm.

[0053] (7) Place the silicon wafer substrate with the precipitated sacrificial layer and a suitable mask on a 100 ℃ hot stage and heat for 5 min. Then, use a pipette to draw 2 mL of carbon nanotube P3-SWNT solution (concentration 0.1 mg / mL, solvent isopropanol) and place it in the volume chamber of the spray gun. The spray gun is held 12 cm above the substrate and then sprayed vertically and uniformly onto the silicon wafer with the sacrificial layer at a rate of 0.2 mL / min. The wafer is then placed on a hot stage and annealed at 100 ℃ for 5 min to obtain a silicon wafer substrate with patterned stretchable source and drain electrodes. The obtained stretchable source and drain electrodes have a thickness of 50-80 nm and a conductivity of 2×10⁻⁶. 5 S·cm -1 .

[0054] (8) Gently peel the prepared stretchable substrate from the glass substrate with the sacrificial layer, and then attach the stretchable substrate to the silicon wafer with the stretchable gate from the other side. Place it in a vacuum drying oven at 60 °C (vacuum degree of 0.1 Pascal) for 20 min to remove air bubbles at the interface during the bonding process so that the substrate completely covers and is bonded to the silicon wafer with the stretchable gate. Then gently peel the fully bonded stretchable substrate and stretchable gate from the silicon wafer to complete the transfer of the stretchable gate. Then, transfer the stretchable insulating layer, stretchable semiconductor layer and stretchable source and drain electrodes to the stretchable substrate in sequence according to the same method to obtain the stretchable polymer nanowire-based transistor, as shown in the figure. Figure 2 The main preparation process is shown below.

[0055] Comparative Example 1 This comparative example shows the fabrication of a stretchable thin-film transistor based on a spin-coating process, following the steps outlined below.

[0056] The preparation method is the same as in Example 1, except for step 6), which is as follows: The silicon wafer substrate with the precipitated sacrificial layer is placed at the center of the spin coater rotor. 30 μL of FIID-CF3TVT / SEBS solution (10 mg / mL, chlorobenzene solvent, FIID-CF3TVT / SEBS mass ratio of 3:7) is taken with a 50 μL pipette and evenly dropped onto the substrate. The spin coater is started at 2000 rpm for 1 min, and then placed on a hot plate at 150 ℃ for 30 min. The thickness of the resulting stretchable film is 150 nm.

[0057] Example 2 The preparation method was exactly the same as in Example 1, except that the polymer FIID-CF3TVT / SEBS chlorobenzene solution was replaced with IDT-BT / SEBS chlorobenzene solution, and the electrohydraulic printing conditions were changed to an applied voltage of 5.5 kV, an internal liquid supply flow rate of 600 nL / min, an external liquid supply flow rate of 4 μL / min, and a substrate movement speed of 400 mm / s; the remaining steps were the same as in Example 1. The thickness of the stretchable semiconductor layer prepared in this example was 100 nm-200 nm.

[0058] Comparative Example 2 This comparative example shows the fabrication of a bottom-gate top-contact stretchable thin-film transistor following the steps outlined below.

[0059] The remaining steps are the same as those in Example 2, except for step (6), which is as follows: Place the silicon wafer substrate with the precipitated sacrificial layer at the center of the spin coater rotor, and then use a pipette to take 30 uL of IDT-BT / SEBS solution (10 mg / mL, chlorobenzene solvent) and drop it evenly onto the substrate. Start the spin coater, rotate at 2500 rpm, spin coat for 1 min, and then place it on a hot stage at 150 ℃ for 30 min. The thickness of the resulting stretchable film is 150 nm.

[0060] Example 3 The preparation method was exactly the same as in Example 1, except that the polymer FIID-CF3TVT / SEBS chlorobenzene solution was replaced with FIID-CF3TVT chlorobenzene solution (10 mg / mL). The electrofluidic printing conditions were changed to an applied voltage of 5 kV, an internal liquid supply flow rate of 1000 nL / min, an external liquid supply flow rate of 4 μL / min, and a substrate movement speed of 400 mm / s. All other conditions remained the same as in Example 1. The thickness of the stretchable semiconductor layer prepared in this example was 100 nm-200 nm.

[0061] Comparative Example 3 This comparative example demonstrates the fabrication of stretchable thin-film transistors based on the pure polymer solution FIID-CF3TVT.

[0062] The remaining steps are the same as those in Example 1, except for step (6), which is as follows: Place the silicon wafer substrate with the precipitated sacrificial layer at the center of the spin coater rotor, and then use a pipette to take 30 uL of FIID-CF3TVT solution (10 mg / mL, chlorobenzene solvent) and drop it evenly onto the substrate. Start the spin coater, rotate at 2000 rpm, spin coat for 1 min, and then place it on a hot stage at 150 ℃ for 30 min. The thickness of the resulting stretchable film is 150 nm.

[0063] Figure 3 Optical microscope images of the polymer nanowires prepared in Example 1 and their stretched state are shown. Figure 3 As shown in (a) above, the nanowires prepared by this invention exhibit high alignment, controllable width, good uniformity, and smooth morphology. Figure 3 As shown in (b) and (c), the prepared polymer nanowires have excellent mechanical properties, and no breakage occurs even when stretched to 100%, regardless of whether the direction is perpendicular or parallel.

[0064] Figure 4 The images show the UV-Vis absorption spectrum, atomic force microscopy pattern, and grazing incidence X-ray diffraction pattern of the polymer nanowires. Figure 4 As shown in (a), compared to the blended film (Comparative Example 1), the 0-0 / 0-1 oscillation peak intensity ratio of the blended nanowires (Example 1) is significantly increased, with a redshift of 10 nm. This indicates that, compared to the film, the polymer chains of the nanowire structure polymer exhibit a higher degree of molecular aggregation and short-range ordering. Figure 4 As shown in (b), the three-dimensional atomic force microscope image reveals that the nanowire is approximately 150 nm high and 300-400 nm wide, with a cylindrical shape. Figure 4 As shown in (c), the polymer with nanowire structure has a good layered stacking microstructure and π-π conjugated structure.

[0065] Figure 5 The stretchable polymer nanowire-based transistor prepared in Example 1 is shown in the parallel channel direction. Figure 5 a) and vertical channel direction ( Figure 5 b) Transfer characteristic curves under different tensile deformations. Figure 5 Analysis shows that transistors made from polymer nanowires have excellent electrical and mechanical properties. They can still function even when stretched to 100% in either the parallel or perpendicular direction, and their electrical performance does not significantly degrade.

[0066] Figure 6 The figures show the voltage-transfer characteristics of a stretchable nanowire inverter based on polymer nanowires and the current-time curves of a stretchable nanowire adaptive device. Figure 6 As shown in (a), the stretchable nanowire complementary inverter fabricated by horizontal integration of p-type and n-type semiconductor nanowires exhibits a high gain (35.35) at a bias voltage of 60 V. Figure 6 As shown in (b), vertically integrated p-type and n-type semiconductor nanowires can be used to fabricate optically adaptive devices. Under the first light pulse stimulation, the phototransistor current value rapidly decreases to position "a" after reaching its peak current. After the light stimulation is removed, the current value rapidly decreases back to its initial state. When a second light pulse is applied, the current value will again reach its peak at position "a" and then rapidly decrease, and so on, until the current value reaches and remains at a relatively constant value. The device exhibits excellent optical adaptive performance, simulating the self-protective behavior of the human eye under strong light stimulation.

[0067] Figure 6 The experimental method in (a) is as follows: The polymer nanowires prepared in Example 1 are used as the n-type transport functional layer and the polymer nanowires prepared in Example 2 are used as the p-type transport functional layer. The two nanowires are horizontally integrated into the stretchable source and drain electrodes to prepare a complementary inverter. Then, an input voltage of 60V is applied and the output voltage curve is tested.

[0068] Figure 6 The experimental method in (b) is as follows: After transferring the polymer nanowires prepared in Example 1 using SEBS, another layer of polymer nanowires prepared in Example 2 is transferred at a vertical angle to vertically integrate the two nanowires. Then, the stretchable source and drain electrodes are transferred, and the current-time curve is tested under the stimulation of light pulse.

Claims

1. A transistor based on stretchable polymer nanowires, characterized in that: The transistor has a bottom-gate top contact or bottom-gate bottom contact structure, including a stretchable substrate, a stretchable gate, a stretchable insulating layer, a stretchable semiconductor layer, and stretchable source and drain electrodes; The stretchable semiconductor layer is a polymer nanowire; the polymer nanowire is prepared by coaxial electrohydrodynamic printing from a blend solution of conjugated polymer and elastomer polymer.

2. The stretchable polymer nanowire transistor according to claim 1, characterized in that: The conjugated polymer is a naphthalimide polymer, an isoindigo polymer, a thiophene polymer, or a pyrrolopyrrole dione polymer; The elastomer polymer is any one of unsaturated rubber, saturated rubber, and thermoplastic elastomer.

3. The stretchable polymer nanowire transistor according to claim 1, characterized in that: The conjugated polymer is selected from any one of poly-3,6-dithiophene-2-yl-2,5-bis(2-decyltetradecyl)-pyrrolo[3,4-c]pyrrolo-1,4-dione-alt-thiophene-2,5-diyl, polyindothiophene-benzothiadiazole, poly(fluorinated isoindigotrifluoromethylthiophene vinylthiophene), poly{[N,N9-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,59-(2,29-anthiophene)}, poly{2,5-bis(2-octyldodecyl)-3,6-bis(thiophene-2-yl)dione-pyrrolo[3,4-c]pyrrolo-1,4-dione-alt-thiophene[3,2-b]thiophene} and poly(3-hexylthiophene); The elastomer polymer is selected from any one of natural rubber, styrene-butadiene rubber, chloroprene rubber, butyl rubber, ethylene propylene rubber, polydimethylsiloxane, polyether ester elastomer, polyacrylate rubber, hydrogenated styrene-butadiene block copolymer, and polyurethane elastomer.

4. The stretchable polymer nanowire transistor according to any one of claims 1-3, characterized in that: The mass ratio of the conjugated polymer to the elastomer polymer is 1:9 to 9:1; preferably 3:7 to 5:

5. The solvent for the blend solution of the conjugated polymer and the elastomer polymer is any one of chlorobenzene, dichlorobenzene, xylene, and toluene; In the blend solution of the conjugated polymer and the elastomer polymer, the concentration of the polymer is 3 mg / mL to 20 mg / mL.

5. The stretchable polymer nanowire transistor according to any one of claims 1-4, characterized in that: The thickness of the stretchable substrate is 500 µm-2 mm; The thickness of the stretchable gate is 50-100 nm; The thickness of the stretchable insulating layer is 1.2 µm-2.5 µm; The thickness of the stretchable semiconductor layer is 30 nm-500 nm; The thickness of the stretchable source and drain electrodes is 50-100 nm; Both the stretchable substrate and the stretchable insulating layer are made of elastomeric polymers; The stretchable gate, the stretchable source, and the drain electrode are all made of intrinsically stretchable conductive material.

6. The stretchable polymer nanowire transistor according to any one of claims 1-5, characterized in that: In the preparation of the polymer nanowires, the outer liquid is polydimethylsiloxane, silicone oil, hydrogenated styrene-butadiene block copolymer or polymethyl methacrylate; the inner liquid is a blend solution of the conjugated polymer and the elastomer polymer. The applied voltage is 2-10kV; The internal liquid supply flow rate is 200-2000 nL / min; the external liquid supply flow rate is 1-20 µL / min; the substrate movement rate is 1-800 mm / s; and the substrate is annealed at 80-220 °C after printing.

7. A method for fabricating the stretchable polymer nanowire transistor according to any one of claims 1-6, comprising the following steps: (1) Prepare a sacrificial layer on the substrate; (2) A stretchable substrate is prepared on a substrate with a precipitated sacrificial layer; (3) A stretchable gate is fabricated on a substrate with a precipitated sacrificial layer; (4) Prepare a stretchable insulating layer on the substrate of the precipitated sacrificial layer; (5) A stretchable semiconductor layer is prepared on a substrate with a precipitated sacrificial layer by coaxial electrohydrodynamic printing; (6) Fabricate stretchable source and drain electrodes on a substrate with a precipitated sacrificial layer; (7) Gently peel the stretchable substrate prepared in step (2) off the substrate of the precipitated sacrificial layer, and then attach the stretchable substrate to the stretchable gate prepared in step (3) from the other side to achieve complete coverage and attachment to the stretchable gate. Then gently peel the fully attached stretchable substrate and stretchable gate off the substrate to complete the stretchable gate transfer. (8) Transfer the stretchable insulating layer, stretchable semiconductor layer and stretchable source and drain electrodes onto the stretchable substrate in the same way as in step (7) to obtain the stretchable polymer nanowire transistor.

8. A polymer nanowire, characterized in that: The polymer nanowires are prepared by coaxial electrohydrodynamic printing from a blend solution of conjugated polymer and elastomer polymer.

9. The polymer nanowires according to claim 8, characterized in that: The conjugated polymer is a naphthalimide polymer, an isoindigo polymer, a thiophene polymer, or a pyrrolopyrrole dione polymer; The elastomer polymer is any one of unsaturated rubber, saturated rubber, and thermoplastic elastomer; The mass ratio of the conjugated polymer to the elastomer polymer is 1:9 to 9:1; preferably 3:7 to 5:

5. The solvent for the blend solution of the conjugated polymer and the elastomer polymer is any one of chlorobenzene, dichlorobenzene, xylene, and toluene; In the conjugated polymer and elastomer polymer blend solution, the polymer concentration is 3 mg / mL-20 mg / mL; In the preparation of the polymer nanowires, the outer liquid is polydimethylsiloxane, silicone oil, hydrogenated styrene-butadiene block copolymer or polymethyl methacrylate; the inner liquid is a blend solution of the conjugated polymer and the elastomer polymer. The applied voltage is 2-10 kV; The internal liquid supply flow rate is 200-2000 nL / min; the external liquid supply flow rate is 1-20 µL / min; the substrate movement rate is 1-800 mm / s; and the substrate is annealed at 80-220 °C after printing.

10. The use of the polymer nanowires of claim 8 or 9 in the fabrication of stretchable complementary inverters; Application of the polymer nanowires of claim 8 or 9 in the fabrication of stretchable optical adaptive devices; A stretchable complementary inverter comprising the polymer nanowires as described in claim 8 or 9; A stretchable optical adaptive device comprising the polymer nanowires of claim 8 or 9.

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