KR102325698B1 - stretchable electrode ink composition, and stretchable electrode and thin film transistor preparation method using the same - Google Patents

Abstract

The present invention relates to a stretchable electrode ink composition, a stretchable electrode and a method for manufacturing a thin film transistor using the same, and more particularly, to a stretchable electrode ink composition comprising a conductive nano material, a polymer material and an ionic liquid, a stretchable electrode and a thin film transistor using the same It relates to a manufacturing method of

Description

Stretchable electrode ink composition, method for manufacturing stretchable electrode and thin film transistor using same

The present invention relates to a stretchable electrode ink composition, a stretchable electrode using the same, and a method for manufacturing a thin film transistor.

Stretchable electronic devices with bendable and stretchable properties overcome the limitations of the existing inorganic-based semiconductor electronic devices, and are easily attached to the skin or curved parts of people, or are easy to carry, display, energy storage devices, and wearable devices, which are attracting attention recently. As applications including sensors and the like are possible, the need for technology development of related materials and devices is increasing.

In order to realize such a stretchable electronic device, various methods for newly designing device components are being studied so that the device can maintain its performance while being compatible with external force and strain applied to the device.

In this regard, Korean Patent Registration No. 10-1394506 discloses a stretchable thin film transistor having a stretchable substrate, graphene electrodes, a wrinkled inorganic oxide insulating film, and a carbon nanotube channel. There is a problem in that the performance is limited to the stretching performance of the electrode material, that is, graphene. Accordingly, in order for the final stretchable electronic device to have excellent flexibility and stretchability, it is necessary to improve the flexibility and stretchability of the electrode, and thus research and development are required.

On the other hand, stretchable electrodes have the advantage that they can be attached to moving parts and arbitrary surfaces while maintaining constant electrical conductivity despite mechanical deformation, so they can be applied to fields such as displays and wearable electronic devices. In addition to the field of application, it can be applied as a tactile sensing film by using the property of changing electrical resistance to mechanical deformation, so it can be applied to artificial electronic skin, tactile sensor, artificial prosthesis, and robotics.

As a method for manufacturing such a stretchable electrode, there are a method of deforming a geometric structure of a rigid material to have stretchability, and a method of manufacturing a stretchable electrode using an essentially elastic organic material.

Among them, as a conventional technique for manufacturing a stretchable electrode by modifying the geometry of a rigid material, Nano Lett. 2014, 14, and 682-686 disclose a stretchable electrode having a wrinkled structure formed by forming a conductive film on a stretched rubber film and then shrinking it by removing tensile force. However, this method generally requires a multi-step manufacturing process, and also has a problem in that it is difficult to use for designing a precise structure.

In addition, as a method of manufacturing stretchable using organic materials, it is a method of manufacturing stretchable electrodes by combining a conductive filler with electrical conductivity such as metal nanoparticles or carbon nanoparticles with stretchable rubber, T. Someya , Y. Kato, T. Sekitani, S. Iba, Y. Noguchi, Y. Murase, H. Kawaguchi, T. Sakurai, Proc. Natl. Acad. Sci. USA, 102, 12321-12325 (2005) discloses a method for manufacturing a stretchable electrode prepared by using carbon nanoparticles as an intensities filter.

Such a method of imparting elasticity by using an organic material can be easily manufactured by direct printing and roll-to-roll process, etc., so that it can be manufactured at low cost and can be more suitable for large-scale manufacturing, but in the conventional case, stretchability When this is excellent, there is a problem in that the conductivity is low, or when the amount of the conductive filter is increased to increase the conductivity, there is a problem that the elasticity is lowered.

Republic of Korea Patent Registration No. 10-1394506

Nano Lett. 2014, 14, 682-686 T. Someya, Y. Kato, T. Sekitani, S. Iba, Y. Noguchi, Y. Murase, H. Kawaguchi, T. Sakurai, Proc. Natl. Acad. Sci. USA, 102, 12321-12325 (2005)

An object of the present invention is to provide a stretchable electrode ink composition, a stretchable electrode using the same, and a method for manufacturing a thin film transistor.

In order to achieve the above object,

In one aspect of the present invention

containing conductive nanomaterials, polymeric materials and ionic liquids.

A stretchable electrode ink composition is provided.

In addition, in another aspect of the present invention

dissolving the stretchable electrode ink composition in a solvent to prepare an electrode ink; and

There is provided a method of manufacturing a stretchable electrode comprising a; printing the electrode ink on a substrate.

Furthermore, in another aspect of the present invention

printing the source electrode and the drain electrode so as to be spaced apart from each other on a substrate using the electrode ink including the stretchable electrode ink composition;

printing a semiconductor layer connecting the source electrode and the drain electrode on the substrate using a semiconductor ink;

printing a dielectric layer on the semiconductor layer using an ion gel ink; and

There is provided a method of manufacturing a thin film transistor comprising; printing a gate electrode on the dielectric layer using a conductive ink.

Furthermore, in another aspect of the present invention

printing a gate electrode, a source electrode, and a drain electrode to be spaced apart from each other on a substrate using the stretchable electrode ink composition;

printing a semiconductor layer connecting the source electrode and the drain electrode on the substrate using a semiconductor ink; and

There is provided a method of manufacturing a thin film transistor comprising; printing a dielectric layer on the semiconductor layer using an ion gel ink.

Furthermore, in another aspect of the present invention

preparing an inverter resistance ink by dissolving a multi-walled carbon nanotube, a polymer material, and an ionic liquid in a solvent;

forming an inverter resistor by printing the resistive ink on a substrate; and

There is provided a method of manufacturing a stretchable inverter comprising a; electrically connecting the inverter resistor and the thin film transistor manufactured by the manufacturing method.

The stretchable electrode ink composition of the present invention can produce a stretchable electrode having a small resistance change according to elongation and contraction.

In addition, the thin film transistor and inverter manufactured by the manufacturing method of the present invention may be a stretchable device or a flexible device that is operated at a low operating voltage and has excellent device stability against stretching or flexible change.

1 is a photograph showing a state when the tensile strain of a stretchable electrode manufactured according to an embodiment of the present invention is 0%, 60% and 120%;
2 is a graph showing _{the resistance change (ΔR/R 0} ) value according to the tensile strain of the stretchable electrode manufactured according to Example 1 and Comparative Example 1 of the present invention;
3 is a photograph observed with a scanning electron microscope (SEM) at tensile strains of 0%, 60% and 120% of the stretchable electrode manufactured according to an embodiment of the present invention;
4 is a graph comparing different resistance values in composition ratios of stretchable electrodes manufactured according to Examples and Comparative Examples of the present invention;
5 is a photograph showing electrode ink, semiconductor ink, ion gel ink, and gate electrode ink manufactured according to an embodiment of the present invention;
6 is a schematic diagram showing a process of manufacturing a thin film transistor by a printing process according to an embodiment of the present invention;
7 is a schematic diagram showing a top gate type flexible thin film transistor according to an embodiment of the present invention;
8 is a photograph showing a flexible thin film transistor manufactured on PET, PI, and paper according to an embodiment of the present invention;
9 to 11 are graphs of the results of measuring the characteristics of the top gate type flexible thin film transistor manufactured according to Example 4 of the present invention;
12 is a graph showing the result of measuring the device characteristics of the flexible thin film transistor manufactured according to Example 5 of the present invention;
13 is a graph showing the result of measuring the device characteristics of the flexible thin film transistor manufactured according to Example 6 of the present invention;
14 is a photograph showing a state in which a thin film transistor is formed on a substrate having a curvature in order to evaluate the flexible stability of the thin film transistor of the present invention;
_{15 to 17 each shows I DS} -V _GS characteristics at various bending radii (r) of the flexible thin film transistor formed as in FIG. 14, hole mobility (μ) according to the bending cycle, threshold voltage (V _th ), I _Ds and the on-off current ratio (I _on /I _off ) is a measured graph,
18 is a schematic diagram showing a side-gate type thin film transistor according to Example 7 of the present invention;
19 to 22 are graphs as a result of measuring the characteristics of a side gate type thin film transistor manufactured according to Example 7 of the present invention;
23 and 24 are graphs as a result of measuring the characteristics of the stretchable inverter manufactured according to Example 8 of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiment of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided in order to more completely explain the present invention to those of ordinary skill in the art. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for clearer description, and elements indicated by the same reference numerals in the drawings are the same elements. In addition, the same reference numerals are used throughout the drawings for parts having similar functions and functions. In addition, "including" a certain element throughout the specification means that other elements may be further included, rather than excluding other elements, unless otherwise stated.

In one aspect of the present invention

containing conductive nanomaterials, polymeric materials and ionic liquids.

A stretchable electrode ink composition is provided.

Hereinafter, the stretchable electrode ink composition according to an embodiment of the present invention will be described in detail.

The stretchable electrode ink composition may include a conductive nano material.

The conductive nanomaterial may be at least one of carbon nanotubes, graphene, metal nanowires, and conductive polymers, and may preferably be single walled carbon nanotubes (SWCNTs) having a lower resistance value.

Accordingly, the stretchable electrode ink composition may include a single-walled carbon nanotube and an ion gel, and the dispersibility of the single-walled carbon nanotube is relatively increased by the ion gel, thereby further improving properties as an electrode.

In addition, the stretchable electrode ink composition may include an ionic liquid. The ionic liquid is a material composed of an organic cation and an organic or inorganic anion, and may be a material having excellent electrochemical stability and high electric capacity and ionic conductivity.

The ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]), 1-butyl-3-methylimidazolium bis(trifluoro Methylsulfonyl)imide ([BMI][TFSI]), 1-butyl-3-methylimidazolium hexafluorophosphate ([BMI][PF ₆ ]), 1-butyl-3-methylimidazolium tetra Fluoroborate (BMI][BF ₄ ]), 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [BMPYR][TFSI], 1-butyl-1-methylpyrrolidinium Tris (pentafluoroethyl) trifluorophosphate ([BMPYR] [FAP]), 1-ethyl-3-methylimidazolium tris (pentafluoroethyl) trifluorophosphate [EMI] [FAP], 1- Ethyl-3-methylimidazolium bis(fluorosulfonyl)imide ([EMI][FSI]) and ethyl-dimethyl-propylammotium bis(trifluoromethylsulfonyl)imide ([EDMPA][TFSI] ]) may be at least one selected from the group consisting of, preferably 1-ethyl-3methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]).

Meanwhile, the ionic liquid may be supported by the polymer material to form an ionic gel in a solid state. The ionic gel imparts the mechanical properties of a polymer material to the ionic liquid, and may exhibit excellent thermal, chemical, and electrochemical stability by the ionic liquid and excellent mechanical properties by the polymer material.

In this case, the polymer material may be at least one of a homopolymer, a copolymer, a multi-copolymer, and a mixture thereof.

Accordingly, the polymer material is polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polyvinyl chloride (PVC), polyvinyl alcohol (PVA), polyethylene (PE), polypropylene (PP), and polystyrene It may be a homopolymer selected from the group consisting of (PS) or a copolymer including the same, but may preferably be a polyvinylidene fluoride (PVDF) copolymer exhibiting high capacity characteristics when used as a dielectric layer of a thin film transistor, and poly ( More preferably, it is vinylidene fluoride-co-hexafluoro propylene (P(VDF-HFP)).

Accordingly, the ionic gel may preferably include the ionic liquid and P (VDF-HFP).

On the other hand, the stretchable electrode ink composition may have a different resistance value depending on the composition ratio of the conductive nano material, the polymer material, and the ionic liquid, and in order to have a lower resistance value, the conductive nano material, the polymer material and the ionic liquid are 1 It may be included in a weight ratio of 1:1:0.3 to 1:1:4, preferably in a weight ratio of 1:1:0.5 to 1:1:2.5, and more preferably 1:1:0.5 to 1 It may be included in a weight ratio of 1:1:1.5. In addition, the conductive nano material and the ion gel may be included in a weight ratio of 1:1.5 to 1:3.5, preferably 1:1.5 to 1:2.5 by weight.

The stretchable electrode ink composition according to an embodiment of the present invention may be an electrode ink composition for manufacturing a gel-type stretchable electrode. In addition, the stretchable electrode ink composition may be used to form at least one of a source electrode, a drain electrode, and a gate electrode of a thin film transistor through a printing process. In this case, the electrode manufactured by the stretchable electrode ink composition may have very small resistance changes due to not only bending but also relaxation and contraction. That is, stability according to stretching stress may be remarkably excellent.

On the other hand, in another aspect of the present invention

dissolving the stretchable electrode ink composition in a solvent to prepare an electrode ink; and

There is provided a method of manufacturing a stretchable electrode comprising a; printing the electrode ink on a substrate.

Hereinafter, a method of manufacturing a stretchable electrode according to an embodiment of the present invention will be described in detail for each step.

The method of manufacturing a stretchable electrode according to an embodiment of the present invention may include preparing the electrode ink by dissolving the stretchable electrode ink composition in a solvent.

The preparing of the electrode ink may be a step of dissolving the stretchable electrode ink composition according to an embodiment of the present invention in a solvent.

In this case, the solvent is not particularly limited as long as it dissolves the polymer material and the ionic liquid, and dimethylformamide (DMF) may be preferably used.

The preparing of the electrode ink may further include stirring at 30 to 70°C. This is for dissolving and uniformly dissolving the conductive nano material, polymer material and ionic liquid in the solvent. can In addition, in the stirring, the ink may be sonicated to more uniformly disperse the conductive nano-material, the polymer material, and the ionic liquid.

Next, the method of manufacturing a stretchable electrode according to an embodiment of the present invention may include printing the electrode ink on a substrate.

In this case, the substrate may preferably have at least one of stretchability and flexibility.

The substrate is a flexible substrate, polyethylene terephthalate (PET), polyimide (PI, polyimide), polyethersulfone (PES, polyethersulphone), polyacrylate (PAR, polyacrylate), polyether imide (PET) , polyetherimide), polyethylene naphthalate (PEN, polyethyelenen napthalate), polyphenylene sulfide (PPS, polyphenylene sulfide), polyallylate, polycarbonate (PC), cellulose triacetate (TAC) and cellulose acetate propionate It may be one or more selected from the group consisting of (CAP: cellulose acetate propinoate), but is not limited thereto, and various materials having flexibility may be used.

In addition, the substrate is a stretchable polymer substrate, eco-flex (ECO-FLEX), polydimethylsiloxane (PDMS, polydimethylsiloxane), polyurethane (PU, polyurethane) polyisoprene (polyisoprene), polybutadiene (polybutadiene), At least one selected from the group consisting of acrylonitrile-butadiene rubber (NBR, acrylonitrile butadiene rubber) and styrene-butadiene rubber (SBR, styrene-butadiene rubber) may be used, but it is not limited thereto, and various materials having elasticity may be used can

The temperature of the substrate may be preferably maintained at a temperature higher than room temperature for smooth solvent removal. Accordingly, the temperature of the substrate may be maintained at 30 ° C. to 220 ° C., preferably at 50 ° C. to 200 ° C., preferably at 100 to 160 ° C., more preferably at a temperature of 130 ° C. can keep

This is for using a flexible substrate or a stretchable polymer substrate as the substrate, and may be for quickly removing the solvent contained in the ink printed on the substrate.

In the method of manufacturing a thin film transistor of the present invention, the entire process can be performed at a temperature of 130° C. or less, so that various substrates requiring a low-temperature process can be used.

In addition, the printing may be performed by one method selected from spin coating, spray coating, inkjet printing and screen printing, flexo, gravure, and roll-to-roll, but may be preferably performed by a spray coating method.

For example, the stretchable electrode may be formed by spray-coating the electrode ink on the substrate at 130° C. in an atmospheric state and a gas pressure of 1.0 bar to 2.0 bar.

The method of manufacturing a stretchable electrode according to an embodiment of the present invention may further include drying the printed ink after the printing step.

This is a step for completely removing the solvent in the ink, and may be performed at a temperature of 130° C. or less, may be performed at a temperature of 25° C. to 130° C., and may be performed at a temperature of 50° C. to 100° C.

The stretchable electrode manufactured according to the embodiment of the present invention is a gel-type electrode, has excellent electrical properties and mechanical stability, and has excellent stability against stretching stress such as relaxation and contraction, so that flexible electronic devices, wearable electronics, etc. It can be used for electrodes of devices, smart sensors, etc.

On the other hand, in another aspect of the present invention

printing the source electrode and the drain electrode so as to be spaced apart from each other on a substrate using the stretchable electrode ink composition;

printing a semiconductor layer connecting the source electrode and the drain electrode on the substrate using a semiconductor ink;

printing a dielectric layer on the semiconductor layer using an ion gel ink; and

There is provided a method of manufacturing a thin film transistor comprising; printing a gate electrode on the dielectric layer using a conductive ink.

The manufacturing method of the thin film transistor may be a method of manufacturing an Electrolyte Gated Transistor (EGT) using a top-gate type electrolyte as a gate insulator as a stack printing method.

In the top gate type thin film transistor, the source electrode 120 and the drain electrode 130 are spaced apart on the substrate 110 as shown in FIG. 7 , and the source electrode 120 and the drain electrode 130 are connected to each other. The semiconductor layer 140 may be disposed, the dielectric layer 150 may be formed on the semiconductor layer 140 , and the gate electrode 160 may be formed on the dielectric layer 150 .

In addition, the printing may be performed by any one method selected from spin coating, spray coating, inkjet printing and screen printing, flexo, gravure, and roll-to-roll, and the same method may be used in all steps, but is not limited thereto. .

Hereinafter, a method of manufacturing a thin film transistor according to an embodiment of the present invention will be described in detail for each step.

The method of manufacturing a thin film transistor according to an embodiment of the present invention may include printing the source electrode and the drain electrode so as to be spaced apart from each other on a substrate using the electrode ink including the stretchable electrode ink composition.

The above step is a step for forming a source electrode and a drain electrode in the form of a gel having excellent elasticity on the substrate.

In this case, the substrate may be a flexible substrate or a stretchable substrate, and when a flexible substrate is used, a flexible thin film transistor may be manufactured, and when a stretchable substrate is used, a stretchable thin film transistor may be manufactured.

In this case, the conductive ink composition may include a conductive nano material, a polymer material, and an ionic liquid, and the conductive nano material may be at least one of carbon nanotubes, graphene, metal nanowires, and conductive polymers, preferably may be single walled carbon nanotubes (SWCNTs) having a lower resistance value.

In this case, the temperature of the substrate may be preferably maintained at a temperature higher than room temperature for smooth solvent removal. Accordingly, the temperature of the substrate may be maintained at 30 ° C. to 220 ° C., preferably at 50 ° C. to 200 ° C., preferably at 100 to 160 ° C., more preferably at a temperature of 130 ° C. can keep

After forming a mask on the substrate, the source electrode and the drain electrode may be spaced apart by printing the electrode ink.

In this case, a plurality of transistors may be simultaneously formed on the substrate by using the mask on which the pattern is formed.

Also, the printing of the source electrode and the drain electrode may further include drying the electrode ink composition after printing. This is a step for completely removing the solvent in the electrode ink, and may be performed at a temperature of 130° C. or less, may be performed at a temperature of 25° C. to 130° C., and may be performed at a temperature of 50° C. to 100° C.

The method of manufacturing a thin film transistor according to an embodiment of the present invention may include printing a semiconductor layer connecting the source electrode and the drain electrode on the substrate using a semiconductor ink.

The printing of the semiconductor layer may further include preparing the semiconductor ink, and the semiconductor ink may be prepared by dissolving an organic semiconductor in a solvent.

The organic semiconductor is preferably a thiophene-based polymer semiconductor, and the semiconductor ink is poly(3-hexylthiophene) (P3HT), poly(2-hexylthiophene), poly(3,3'''-didodecylquater). thiophene) (PQT-12), poly (9,9'-dioctyl fluorene-co-bithiophene) (F8T2), and mixtures thereof may include any one selected from the group consisting of, preferably It may be a regular P3HT (regioregular P3HT).

In addition, the solvent is not particularly limited as long as it dissolves the organic semiconductor, and specifically may be chloroform.

After forming a mask on the substrate on which the source electrode and the drain electrode are formed, a semiconductor layer connecting the source electrode and the drain electrode may be formed by printing the semiconductor ink.

Also, the printing of the semiconductor layer may further include drying the semiconductor ink after printing the semiconductor ink.

The method of manufacturing a thin film transistor according to an embodiment of the present invention may include printing a dielectric layer on the semiconductor layer using ion gel ink.

The printing of the dielectric layer may further include preparing the ion gel ink, and the ion gel ink may be prepared by dissolving the ion gel in a solvent.

In this case, the ionic gel is a material in which an ionic liquid is supported by a polymer material, and includes an ionic liquid and a polymer material, and thus exhibits excellent thermal, chemical, and electrochemical stability while exhibiting excellent mechanical properties. .

In addition, since the ion gel does not vaporize during the process due to low vapor pressure, loss due to vaporization can be minimized and temperature stability is remarkably excellent.

The ionic liquid is bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMI] [TFSI]), 1-butyl-3-methylimidazolium hexafluorophosphate ([BMI][PF ₆ ]), 1-butyl-3-methylimidazolium tetrafluoroborate (BMI][BF ₄ ] ), 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [BMPYR][TFSI], 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluoro Phosphate ([BMPYR] [FAP]), 1-ethyl-3-methylimidazolium tris (pentafluoroethyl) trifluorophosphate [EMI] [FAP], 1-ethyl-3-methylimidazolium bis ( one selected from the group consisting of fluorosulfonyl)imide ([EMI][FSI]) and ethyl-dimethyl-propylammotium bis(trifluoromethylsulfonyl)imide ([EDMPA][TFSI]) or more, preferably 1-ethyl-3methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]).

In addition, the polymer material may be at least one of a homopolymer, a copolymer, a multi-copolymer, and a mixture thereof.

Accordingly, the polymer material is polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polyvinyl chloride (PVC), polyvinyl alcohol (PVA), polyethylene (PE), polypropylene (PP), and polystyrene It may be a homopolymer selected from the group consisting of (PS) or a copolymer containing the same, but may preferably be a polyvinylidene fluoride (PVDF) copolymer to form a dielectric layer exhibiting high capacity characteristics, and poly (vinylidene) It may more preferably be fluoride-co-hexafluoro propylene (P(VDF-HFP)), and the ionic gel may preferably include the ionic liquid and P(VDF-HFP).

In addition, the solvent is not particularly limited as long as it dissolves the ion gel, and specifically may be acetone.

Printing the dielectric layer may further include drying the ion gel ink after printing.

Since the dielectric layer formed through the above step is composed of ion gel, the thin film transistor manufactured by the above manufacturing method can have a very high specific capacitance, which enables the device to be driven at a low voltage and consumes very little power, making it suitable for portable devices. It can be advantageous to apply.

The method of manufacturing a thin film transistor according to an embodiment of the present invention may include printing a gate electrode on the dielectric layer using a conductive ink.

Printing the gate electrode may further include preparing the conductive ink.

In this case, the conductive ink may be the same as the electrode ink used to form the source electrode and the drain electrode, but may preferably include a conductive polymer, and more preferably include PEDOT:PSS used as a transparent electrode. can

On the other hand, in order to smoothly remove the solvent when printing the conductive ink, the temperature of the substrate may be maintained at 25 ° C. to 100 ° C., it may be maintained at 40 to 90 ° C., and preferably at 70 to 90 ° C. .

Also, the printing of the gate electrode may further include drying the conductive ink after printing.

The manufacturing method of the thin film transistor according to an embodiment of the present invention can be manufactured at low cost because the entire configuration of the transistor can be manufactured by a printing process, so it can be manufactured at low cost, and it is easy to manufacture, and a continuous process is possible, so that a large area and a large amount of it are possible. It may be easier to produce.

In addition, the thin film transistor manufactured according to an embodiment of the present invention can operate at a low operating voltage of 1V or less, exhibit a high output current, have an excellent on/off current ratio, and further expand and contract Because of its excellent stability against stress, it can be used in next-generation flexible devices or wearable devices.

On the other hand, in another aspect of the present invention

printing a gate electrode, a source electrode, and a drain electrode to be spaced apart from each other on a substrate using the stretchable electrode ink composition;

printing a semiconductor layer connecting the source electrode and the drain electrode on the substrate using a semiconductor ink; and

There is provided a method of manufacturing a thin film transistor comprising; printing a dielectric layer on the semiconductor layer using an ion gel ink.

The manufacturing method of the thin film transistor may be a method of manufacturing an Electrolyte Gated Transistor (EGT) using a side-gated type electrolyte as a gate insulator as a stack printing method.

In the side gated thin film transistor 200, as shown in FIG. 18, a gate electrode 260, a source electrode 220, and a drain electrode 230 are spaced apart from each other on a substrate 210, and the source electrode ( 220 ) and a semiconductor layer 240 connecting the drain electrode 230 may be disposed, and a dielectric layer 250 may be formed on the semiconductor layer 240 .

The manufacturing method is the method of forming the semiconductor layer and the dielectric layer, except that the gate electrode, the source electrode, and the drain electrode are simultaneously printed using the electrode ink containing the electrode ink composition on the substrate. The manufacturing method may be the same.

On the other hand, in another aspect of the present invention

preparing an inverter resistance ink by dissolving a multi-walled carbon nanotube, a polymer material, and an ionic liquid in a solvent;

forming an inverter resistor by printing the resistance ink on a stretchable substrate; and

and electrically connecting the inverter resistor and the thin film transistor manufactured by the manufacturing method.

The inverter according to an embodiment of the present invention connects a resistor including a multi-walled carbon nanotube to the thin film transistor, has excellent voltage transfer performance at a low operating voltage of 1V or less, and has a small change value for stretch deformation, It is a stretchable inverter with remarkably excellent performance as a stretchable element.

Hereinafter, a method of manufacturing a stretchable inverter according to an embodiment of the present invention will be described in detail for each step.

The method of manufacturing a stretchable inverter according to an embodiment of the present invention may include preparing an inverter resistance ink by dissolving a multi-walled carbon nanotube, a polymer material, and an ionic liquid in a solvent.

In this case, the resistance ink may include multi-walled carbon nanotubes, a polymer material, and an ionic liquid.

In this case, the polymer material may be at least one of a homopolymer, a copolymer, a multi-copolymer, and a mixture thereof. Accordingly, the polymer material is polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polyvinyl chloride (PVC), polyvinyl alcohol (PVA), polyethylene (PE), polypropylene (PP), and polystyrene It may be a homopolymer selected from the group consisting of (PS) or a copolymer including the same, but may preferably be a polyvinylidene fluoride (PVDF) copolymer exhibiting high capacity characteristics when used as a dielectric layer of a thin film transistor, and poly ( More preferably, it is vinylidene fluoride-co-hexafluoro propylene (P(VDF-HFP)).

In addition, the ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]), 1-butyl-3-methylimidazolium bis(tri Fluoromethylsulfonyl)imide ([BMI][TFSI]), 1-butyl-3-methylimidazolium hexafluorophosphate ([BMI][PF ₆ ]), 1-butyl-3-methylimida zolium tetrafluoroborate (BMI][BF ₄ ]), 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [BMPYR][TFSI], 1-butyl-1-methylpyr Rollidinium tris (pentafluoroethyl) trifluorophosphate ([BMPYR] [FAP]), 1-ethyl-3-methylimidazolium tris (pentafluoroethyl) trifluorophosphate [EMI] [FAP], 1-Ethyl-3-methylimidazolium bis(fluorosulfonyl)imide ([EMI][FSI]) and ethyl-dimethyl-propylammotium bis(trifluoromethylsulfonyl)imide ([EDMPA] [TFSI]) may be at least one selected from the group consisting of, preferably 1-ethyl-3methylimidazolium bis(trifluoromethyl sulfonyl)imide ([EMI][TFSI]).

On the other hand, the resistance ink may have a different resistance value depending on the composition ratio of the multi-walled carbon nanotube, the polymer material, and the ionic liquid, and may preferably include a weight ratio of 1:1:0.3 to 1:1:4. and more preferably in a weight ratio of 1:1:0.5 to 1:1:2.5, and more preferably in a weight ratio of 1:1:0.5 to 1:1:1.5.

Also, the method of manufacturing a stretchable inverter according to an embodiment of the present invention may include forming an inverter resistor by printing the resistance ink on a stretchable substrate.

The printing method may be performed in the same manner as the thin film transistor printing method, but is not limited thereto, and various printing methods may be used.

A gel-type inverter resistor may be manufactured through the printing, and the gel-type inverter resistor may have a very small change in resistance due to not only bending but also relaxation and contraction. That is, stability according to stretching stress may be remarkably excellent.

Also, the method of manufacturing a stretchable inverter according to an embodiment of the present invention may include electrically connecting the inverter resistor and the thin film transistor manufactured by the manufacturing method.

The method for manufacturing a stretchable inverter according to an embodiment of the present invention can be manufactured at a low cost because all components constituting the inverter can be manufactured by a printing process, and it is easy to manufacture, and a continuous process is possible, so that it is suitable for large-area and mass production. It could be easier.

Hereinafter, the present invention will be described in detail through Examples and Experimental Examples.

However, the following Examples and Experimental Examples are merely illustrative of the present invention, and the content of the present invention is not limited by the following Examples.

<Example 1> Stretchable electrode

Step 1: Dissolve single-walled carbon nanotubes (SWCNTs), P(VDF-HFP) and [EMI][TFSI] in 15mL of dimethylformamide (DMF) of 8mg each to obtain single-walled carbon nanotubes, [EMI] ][TFSI] and P(VDF-HFP) were prepared as 1:1:1 electrode ink. For uniform dispersion of the single-walled carbon nanotubes (SWCNT), P(VDF-HFP) and [EMI][TFSI], the mixture was stirred at 50° C. for one hour, and then bar-sonicated for one hour.

Step 2: The electrode ink was spray-printed on an ECO-FLEX stretchable substrate to form a stretchable electrode having a length of 1200 μm, a thickness of 3 μm and a width of 200 μm.

<Example 2> Stretchable electrode

Example except that in step 1 of Example 1, electrode ink containing single-walled carbon nanotubes, P(VDF-HFP) and [EMI][TFSI] was prepared in a ratio of 1:1:2 A stretchable electrode was formed in the same manner as in 1 .

<Example 3> Stretchable electrode

Example except that in step 1 of Example 1, electrode ink containing single-walled carbon nanotubes, P(VDF-HFP), and [EMI][TFSI] was prepared in a ratio of 1:1:3 A stretchable electrode was formed in the same manner as in 1 .

<Example 4> Top-gate flexible thin film transistor

Step 1: As shown in FIG. 5, electrode ink was prepared by dissolving single-walled carbon nanotubes, P(VDF-HFP) and [EMI][TFSI] in 15 mL of dimethylformamide (DMF) of 8 mg each, and the position was regular A semiconductor ink was prepared by dissolving 1 mg of poly(3-hexylthiophene) (regioregular P3HT) in 1 mL of chloroform, and P(VDF-HFP), [EMI][TFSI] and acetone were mixed in a ratio of 1:9:40 The ion gel ink was prepared by mixing, and 0.1 mL of ethylene glycol, 1 mL of PEDOT:PSS, and 0.5 mL of DI-water were mixed to prepare a gate electrode ink.

Step 2: As shown in FIG. 6, patterned stencil masks were placed on a PET (polyethylene terephthalate) flexible substrate to form 30 transistor devices, and then the stencil masks were placed using an airbrush with a nozzle size of 250 μm. Source and drain electrodes were formed by spray-printing 2 ml of electrode ink 10 on a PET substrate. At this time, the temperature of the substrate was maintained at 130°C. Thereafter, in order to remove the solvent from the printed electrode, it was dried under vacuum and 130° C. conditions for 2 hours.

Step 3: After that, stencil masks are placed in the same manner using the airbrush, and then 0.4 mL of semiconductor ink (20) and 0.8 mL of ion gel ink (30) are spray-printed on the source and drain electrodes to print the semiconductor. Layers and dielectric layers were formed. At this time, the temperature of the substrate was maintained at 50 °C.

Step 4: Thereafter, stencil masks were placed in the same manner using the airbrush, and then 0.8 mL of gate electrode ink 40 was spray-printed to form a gate electrode. At this time, the temperature of the substrate was maintained at 80 °C.

All of the spray printing processes were performed in the atmosphere at a substrate temperature of 130° C. or less, and a gas pressure of 1.5 bar was performed.

Step 5: Thereafter, 30 top gate thin film transistors of the form of FIG. 7 were printed on a PET substrate by drying under vacuum and 50° C. conditions for 24 hours to remove residual solvent.

<Example 5> Top gate type flexible thin film transistor

A flexible thin film transistor was manufactured in the same manner as in Example 4, except that in step 2 of Example 4, a flexible substrate was used differently as polyimide (PI).

<Example 6> Top gate type flexible thin film transistor

A flexible thin film transistor was manufactured in the same manner as in Example 4, except that in step 2 of Example 4, a flexible substrate was used differently as paper.

<Embodiment 7> Side-gated stretchable thin film transistor

Using the electrode ink, semiconductor ink, and ink gel ink of the same composition as in Example 4, the side gated stretchable thin film transistor as shown in FIG. 18 was printed on an ECO-FLEX stretchable substrate by performing the following method. did.

Step 1: After placing the patterned stencil masks on the ECO-FLEX stretchable substrate, using an airbrush with a nozzle size of 250 μm, 2 ml of the stencil masks were placed on the ECO-FLEX substrate. Electrode ink was spray-printed to form gate, source, and drain electrodes spaced apart. At this time, the spray process was performed in the air, and the temperature of the substrate was maintained at 130° C. or less. Thereafter, in order to remove the solvent from the printed electrode, it was dried under vacuum and 130° C. conditions for 2 hours.

Step 2: After that, after placing stencil masks in the same way using the airbrush, 0.4 mL of semiconductor ink and 0.8 mL of ion gel ink are spray-printed on the gate, source and drain electrodes to form the semiconductor and dielectric layers. formed. At this time, the spray process of the semiconductor ink and the ion gel ink was performed in the air, and the temperature of the substrate was maintained at 50°C.

Step 3: Thereafter, it was dried under vacuum and 50° C. conditions for 24 hours to remove residual solvent.

<Embodiment 8> Elastic inverter

Step 1: Prepare an inverter resistance ink in which multi-walled carbon nanotube (MWCNT), P(VDF-HFP) and [EMI][TFSI] are dissolved in acetone in a 1:1:1 ratio, and the multi-walled carbon nanotube (MWCNT) For uniform dispersion of multi walled carbon nanotube (MWCNT), P(VDF-HFP) and [EMI][TFSI], the mixture was stirred at 50 °C for one hour, and then bar-sonicated for one hour.

Step 2: Multi-walled carbon nanotube (MWCNT)-based inverter resistance by spray-printing the inverter resistance ink prepared in step 1 so as to be spaced apart from the drain electrode of the side gated planar thin film transistor of Example 7 was formed to manufacture a stretchable inverter.

<Comparative Example 1> Stretchable electrode

A stretchable electrode was formed by spray coating single-walled carbon nanotubes on an ECO-FLEX stretchable substrate.

<Comparative Example 2> Stretchable electrode

In Step 1 of Example 1, the single-walled carbon nanotubes, [P(VDF-HFP) and [EMI][TFSI] were prepared in a 1:1:0 ratio, except for the production of electrode ink. A stretchable electrode was formed in the same manner as in Example 1.

<Experimental Example 1> Measurement of resistance change according to stretching of a stretchable electrode

_{In order to check the resistance change (ΔR/R 0} ) according to the stretching of the stretchable electrode according to an embodiment of the present invention, the length of the stretchable electrode prepared in Example 1 and Comparative Example 1 is increased, as shown in FIG. 1 , After forming in a tensile strain state of 0%, 60%, and 120%, the resistance change (ΔR/R ₀ ) in each of the tensile strain states was measured, and the results are shown in FIG. 2 .

As shown in FIG. 2 , it can be seen that the electrode of Example 1 has a smaller resistance change than the electrode of Comparative Example 1 at the same tensile strain. That is, in the case of the electrode of Comparative Example 1, a resistance change of 2 or more was exhibited at 60% tensile strain, and a resistance change of 10 or more was shown at a tensile strain of 120%, whereas, in the case of the electrode of Example 1, a resistance of about 0.2 at 60% tensile strain. It can be seen that only a change occurs, and the change in resistance is about 1 even at a tensile strain of 120%, indicating that the change in resistance to tensile strain is remarkably small. can

3 is a photograph of the surface of the electrode of Example 1 observed with a scanning electron microscope (SEM) at tensile strains of 0%, 60%, and 120%, and the electrode at 0% tensile strain is about It can be seen that it is composed of multiple microdomains of 100 μm or less, and it can be seen that several micro-sized side cracks are generated in the state of 60% tensile strain, and that the cracks are larger in the state of 120% tensile strain. Able to know. The reason why the resistance change is small up to the state where the tensile strain is 120% in spite of the surface change as described above is because the electrode remains electrically connected even when cracks occur.

<Experimental Example 2> Measurement of resistance value according to composition ratio of stretchable electrode composition

In order to check the resistance value according to the composition ratio of the stretchable electrode manufactured according to the embodiment of the present invention, the resistance value was measured for the electrodes of Examples 1 to 3 and Comparative Example 2 using a resistance measuring device, and the results are shown in FIG. 4 shown in

As shown in FIG. 4 , it can be seen that Example 1 exhibits the smallest resistance value.

<Experimental Example 3> Confirmation of top gate type flexible thin film transistor

As a result of checking the thin film transistors manufactured by Examples 4 to 6 to confirm the thin film transistors manufactured according to the embodiment of the present invention, the entire process was performed as a spray process as shown in FIG. 8 to form PET, PI and paper substrates. It can be seen that the thin film transistor was printed well.

<Experimental Example 4> Characteristics evaluation of top gate type flexible thin film transistor

In order to confirm the device characteristics of the top gate type flexible thin film transistor manufactured in Example 4, a device characteristic test was performed, and the results are shown in FIGS. 9 to 11 .

_{9 is a graph of the current (I DS} ) voltage (V _DS ) of the source-drain electrode when the gate voltage (V _GS ) is applied to -0.1 to -0.7V. As shown in FIG. 9, very small current hysteresis ( I _DS hysteresis) appears, and it can be seen that an appropriate linear region and a saturation region appear at a low voltage.

In addition, FIG. 10 shows a _{transfer curve in a linear region where V DS} is -0.1V. As shown in FIG. 10, the thin film transistor of Example 4 is excellent at a low voltage of 1V or less. It can be seen that the switching characteristics appear, and it can be seen that a small hysteresis and a high on-off current ratio of ^{10 4 or more appear.} In addition, the hole mobility ( μ ) and the threshold voltage (V _th ) in the linear region where _{the V DS} is -0.1V were calculated to be 0.32 cm ² /Vs and 0.4 V, respectively.

On the other hand, as shown in FIG. 11 , a _{linear characteristic appeared between I DS} ^1/2 and V _DS at saturation with _{V DS} of -0.7V, and the hole mobility ( μ ) was 0.62 cm ² /Vs was calculated as In addition, the average on/off current ratio in the linear region of the 30 devices manufactured in Example 4, the hole mobility ( μ ) and As a result of calculating the threshold voltage (V _th ), the on/off current ratio is 1.02 ± 0.19 × 10 ⁴ , the Hall mobility ( μ ) is 0.23 ± 0.07 cm ² /Vs, and the threshold voltage (V _th ) is 0.37 ± 0.05 was calculated as V.

<Experimental Example 5> Evaluation of characteristics of flexible thin film transistors formed on PI and paper substrates

The characteristics of the flexible thin film transistors of Examples 5 and 6 were evaluated in the same manner as in Experimental Example 4, and the results are shown in FIGS. 12 and 13 .

As shown in FIGS. 12 and 13, the flexible thin film transistors of Examples 5 and 6 formed on PI and paper substrates also exhibit excellent switching characteristics like the flexible thin film transistors of Example 4 formed on a PET substrate. it can be seen that

<Experimental Example 6> Flexible stability evaluation

In order to evaluate the flexible stability of the flexible thin film transistor manufactured according to an embodiment of the present invention, the device is formed to have various bending radii (r) as in FIG. 14 for the flexible thin film transistor of Example 4, and then the bending radius _{Transition characteristics were measured in a linear region where V DS} was -0.1 V in a state where (r) was ∞, 12, 7, and 2 mm, and the results are shown in FIG. 15 , and the results are shown in FIG. The results of measuring the hole mobility (μ ) and the threshold voltage (V _th ) by performing the repeated bending test of the cycle are shown in FIG. 16 , the threshold voltage (V _th ), on-current (I _on ), off- The results of measuring the current (I _off ) and the on/off current ratio are shown in FIG. 17 .

As shown in FIG. 15 , it can be seen that _{similar I DS} -V _GS curves appear in the state where the bending radius (r) is ∞, 12, 7, and 2 mm. When the bending radius (r) is ∞, 12, 7, and 2 mm, the tensile strain is calculated using the equation ε=t/2r (t is the thickness of the substrate, r is the bending radius). 0, 0.42, 0.71, and 2.5% with r) of ∞, 12, 7, and 2 mm, respectively.

Through this, it can be seen that the thin film transistor according to the embodiment of the present invention exhibits the same characteristics even in a mechanically deformed state, which can be seen as excellent in characteristics as a flexible device.

In addition, it can be seen through FIGS. 16 and 17 that even when the bending test is performed for 5000 cycles at a bending radius of 1 mm, the performance is maintained almost constant, and through this, the thin film transistor according to Example 4 of the present invention has stability according to deformation. It can be seen that this is excellent.

<Experimental Example 7> Characteristic evaluation of side gated stretchable thin film transistors

In order to confirm the device characteristics of the side gated stretchable thin film transistor manufactured according to Example 7, a device characteristic test was performed, and the results are shown in FIGS. 19 to 22 .

_{19 is a graph showing transition curves in a linear region in which V DS} is -0.3V for the transistor device of Example 7, wherein 0%, 20%, and 40% for the transistor device of Example 8 %, 60%, 80% and 100% of tensile strain, and then restored to the initial state (strain 0%) were measured for each.

19 , it can be seen that the side gated stretchable thin film transistor of Example 7 is also operated at a low voltage of 1 V or less, and the transition characteristics of the device are 0%, 20%, 40%, 60%, 80 It can be seen that similar properties appear even when the initial state (strain 0%) is restored after deformation at % and 100% tensile strain. Through this, it can be seen that the side gated stretchable thin film transistor of Example 8 exhibits excellent switching characteristics at a low voltage and also has excellent flexibility stability.

Figure 20 shows normalized mobility (μ/μ ₀ ) as a function of tensile strain in the vertical and horizontal directions (0%, 20%, 40%, 60%, 80% and 100%) to quantify the performance. ), the change in normalized mobility was maintained at about 90% when stretched by 20% in both the horizontal and vertical directions and about 70% when stretched by 40%.

21 is a tensile strain (0%, 20%, 40%, 60%, 80% and 100%) in the threshold voltage (V _th) value corresponding to a shown a graph, the values threshold voltage (V _th) is larger tensile strain It moves to a more negative (-) value according to

22 shows that the thin film transistor of Example 7 is deformed to 20% tensile strain and then restored to the initial state (strain of 0%) by repeating 5000 cycles of normalized mobility ( μ/μ ₀ ) Stability of As a specific thing, as shown in FIG. 22 , it can be seen that 80% of the performance is maintained even if it is performed 5000 times. Through this, it can be seen that the thin film transistor according to Example 7 has excellent stability due to deformation.

<Experimental Example 8> Characteristic evaluation of flexible inverter

In order to confirm the characteristics of the stretchable inverter manufactured according to Example 8, the following experiments were performed, and the results are shown in FIGS. 23 to 24 .

23 is a graph showing the output voltage (V _{out ) with respect to the input voltage (V in} ) at 0%, 20%, 40% and 60% tensile strain of the inverter manufactured by Example 8, and FIG. 24 is the input voltage A graph showing a gain value for (V _in ), wherein the supply voltage (V _DD ) was set to 0.6V. On the other hand, the circuit diagram inserted in FIG. 23 shows an equivalent circuit diagram of the stretchable inverter of Example 8, and the measurement according to the tensile strain is the initial state after deformation at tensile strains of 0%, 20%, 40%, and 60%. (Strain rate 0%) was measured after recovery.

23 and 24, the inverter of Example 8 at all 0%, 20%, 40% and 60% tensile strain has excellent voltage transfer characteristics and gain even at a very low voltage of 0.6V. ), and the voltage gain (∂V _out /∂V _in ) was measured to be 5.1, 4.9, 4.5, and 3.8 at 0%, 20%, 40%, and 60% tensile strain. _{In addition, the figure inserted in FIG. 24 shows the input voltage value (V inversion} ) when representing the maximum gain value at each of 0%, 20%, 40% and 60% tensile strain, the V _inversion value It can be seen that the change in is very low, about 0.1 V or less, even when the tensile strain is changed.

Accordingly, it can be seen that the stretchable inverter manufactured according to Example 8 has excellent voltage transfer performance at a low operating voltage and has no change value for stretch deformation, and thus has excellent performance as a stretchable element.

10: electrode ink
20: semiconductor ink
30: ion gel ink
40: gate electrode ink
100: top gate type flexible thin film transistor
110: flexible substrate
120: source electrode
130: drain electrode
140: semiconductor layer
150: dielectric layer
160: gate electrode
200: side gated thin film transistor
210: substrate
220: source electrode
230: drain electrode
240: semiconductor layer
250: dielectric layer
260: gate electrode

Claims (15)

flexible substrate; and
Including a; stretchable electrode ink composition printed on the flexible substrate;
The stretchable electrode ink composition comprises carbon nanotubes and ion gels in a weight ratio of 1:1.5 to 1:3.5, a stretchable electrode.
The method of claim 1,
The ion gel comprises a polymer material and an ionic liquid in a weight ratio of 1:0.5 to 1:2.5, a stretchable electrode.

The method of claim 1,
The printing is performed by any one method of spin coating, spray coating, inkjet printing and screen printing, flexo, gravure and roll-to-roll, stretchable electrode.
3. The method of claim 2,
wherein the polymer material is at least one of a homopolymer, a copolymer, a multi-copolymer, and a mixture thereof.
3. The method of claim 2,
The ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMI][TFSI]), 1-butyl-3-methylimidazolium bis(trifluoro Methylsulfonyl)imide ([BMI][TFSI]), 1-butyl-3-methylimidazolium hexafluorophosphate ([BMI][PF ₆ ]), 1-butyl-3-methylimidazolium tetra Fluoroborate (BMI][BF ₄ ]), 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide [BMPYR][TFSI], 1-butyl-1-methylpyrrolidinium Tris (pentafluoroethyl) trifluorophosphate ([BMPYR] [FAP]), 1-ethyl-3-methylimidazolium tris (pentafluoroethyl) trifluorophosphate [EMI] [FAP], 1- Ethyl-3-methylimidazolium bis(fluorosulfonyl)imide ([EMI][FSI]) and ethyl-dimethyl-propylammotium bis(trifluoromethylsulfonyl)imide ([EDMPA][TFSI] ]) at least one stretchable electrode selected from the group consisting of.
preparing an electrode ink by dissolving the stretchable electrode ink composition in a solvent; and
Including; printing the electrode ink on a flexible substrate to produce the stretchable electrode of claim 1;
The method for producing a stretchable electrode, wherein the stretchable electrode ink composition includes carbon nanotubes and ion gels in a weight ratio of 1:1.5 to 1:3.5.
7. The method of claim 6,
The manufacturing of the electrode ink is a method of manufacturing a stretchable electrode performed at a temperature of 50 to 200 ℃.
Printing the source electrode and the drain electrode so as to be spaced apart from each other on a flexible substrate using an electrode ink comprising a stretchable electrode ink composition;
printing a semiconductor layer connecting the source electrode and the drain electrode on the flexible substrate using a semiconductor ink;
printing a dielectric layer on the semiconductor layer using an ion gel ink; and
Including; printing a gate electrode on the dielectric layer using a conductive ink;
The method for manufacturing a thin film transistor, wherein the stretchable electrode ink composition contains carbon nanotubes and ion gels in a weight ratio of 1:1.5 to 1:3.5.
printing a gate electrode, a source electrode, and a drain electrode to be spaced apart from each other on a flexible substrate using a stretchable electrode ink composition;
printing a semiconductor layer connecting the source electrode and the drain electrode on the flexible substrate using a semiconductor ink; and
Including; printing a dielectric layer on the semiconductor layer using ion gel ink,
The method for manufacturing a thin film transistor, wherein the stretchable electrode ink composition contains carbon nanotubes and ion gels in a weight ratio of 1:1.5 to 1:3.5.
10. The method according to claim 8 or 9,
The semiconductor ink is poly(3-hexylthiophene) (P3HT), poly(2-hexylthiophene), poly(3,3'''-didodecylquaterthiophene) (PQT-12), poly(9, A method of manufacturing a thin film transistor comprising any one selected from the group consisting of 9'-dioctyl fluorene-co-bithiophene) (F8T2) and mixtures thereof.
10. The method according to claim 8 or 9,
The ion gel ink is a method of manufacturing a thin film transistor comprising a polymer material and an ionic liquid.
10. The method according to claim 8 or 9,
Before printing the source electrode and the drain electrode, maintaining the substrate at a temperature of 100 to 130 ℃; manufacturing method of a thin film transistor comprising a further.
10. The method according to claim 8 or 9,
Before printing the source electrode and the drain electrode, the manufacturing method of the thin film transistor further comprising the step of forming a mask having a pattern.
10. The method according to claim 8 or 9,
drying at least one of the stretchable electrode ink, semiconductor ink, and ion gel ink;
preparing an inverter resistance ink by dissolving a multi-walled carbon nanotube, a polymer material, and an ionic liquid in a solvent;
forming an inverter resistor by printing the resistance ink on a stretchable substrate; and
10. A method of manufacturing a stretchable inverter comprising: electrically connecting the inverter resistor and the thin film transistor manufactured by the manufacturing method of claim 9.

Images