KR20190071489A - Polymer composition, and transparent conducting polymer thin film with excellent conductivity and flexibility using the same, and transparent electrode using the same and method for manufacturing the same - Google Patents

Abstract

Disclosed are a polymer composition, a transparent conductive polymer thin film with excellent conductivity and flexibility using the same, a transparent electrode using the transparent conductive polymer thin film, and a method for manufacturing the transparent electrode. According to the present invention, the transparent conductive polymer thin film is a cured material of a polymer composition, which includes: 0.1-2 parts by weight of ionic liquid; and 0.1-2 parts by weight of a surfactant with respect to 100 parts by weight of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). According to the present invention, the surfactant is added to the thin film having high conductivity and flexibility, and thus, it is possible to manufacture the thin film on various types of an elastic substrate and the thin film can be used as a conductive thin film for a stretchable electronic element.

Description

TECHNICAL FIELD [0001] The present invention relates to a polymer composition, and a transparent conductive polymer thin film excellent in conductivity and stretchability using the polymer composition, and a transparent electrode using the same, and a transparent electrode using the same, and a method for manufacturing the transparent electrode. AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to a transparent conductive polymer thin film having high conductivity and high elasticity, and more particularly, to a transparent conductive polymer thin film having excellent conductivity and stretchability including a PEDOT: PSS polymer, an ionic liquid and a surfactant, Electrode and a manufacturing method thereof.

Recently, researches on material development for the implementation of strainable electronic devices such as human body attachment type electronic devices have been actively studied, and in particular, researches on flexible conductors that constitute electrodes and conductors of electronic devices have become mainstream. Most stretchable conductors reported so far have obtained elasticity by making the non-stretchable metal material into a bent shape or by mixing it with an elastic body.

However, such stretchable conductors are limited to specific structures and substrates, and their use range is limited in the future. On the other hand, graphene, carbon nanotubes, conductive polymers and the like have been studied as conductors in which the material itself has elasticity. Among them, the conductive polymer can be produced at low cost through mass synthesis, and has a merit that a printing process is easy by forming a stable solution through a complex with a soluble polymer electrolyte.

1 is a graph showing the initial electrical conductivity and the maximum tensile strain of a conductive polymer (PEDOT: PSS) into which additives such as an elastomer, a surfactant, a plasticizer, and a soft polymer are introduced.

Recently, studies for introducing various additives as shown in Fig. 1 have been carried out in order to increase the stretchability of the conductive polymer. However, although the stretchability is increased, the electric conductivity of the conductive polymer is low.

The background art related to the present invention is Korean Patent Registration No. 10-1564587 (registered on October 26, 2015), which discloses a composition containing PEDOT / PSS and a fluorinated polymer and a transparent electrode film using the same.

It is an object of the present invention to provide a transparent conductive polymer thin film excellent in conductivity and stretchability.

Another object of the present invention is to provide a transparent electrode using the transparent conductive polymer thin film.

It is still another object of the present invention to provide a method of manufacturing the transparent electrode.

In order to accomplish the above object, the polymer composition according to the first embodiment of the present invention comprises 0.1 to 2 parts by weight of an ionic liquid per 100 parts by weight of PEDOT: PSS (poly (3,4-ethylenedioxythiophene): polystyrene sulfonate) And 0.1 to 2 parts by weight of a surfactant.

The ionic liquid may be composed of a combination of a cation selected from an imidazolium-based cation or a non-aromatic cation and an anion selected from an aromatic anion, a non-aromatic anion, or a sulfonate anion.

The ionic liquid may be composed of a combination of an imidazolium-based cation and a non-aromatic anion.

The surfactant may include at least one of a surfactant containing ethylene oxide in the main chain, a surfactant containing a fluorine group in the main chain, an anionic surfactant and an amphoteric surfactant.

The amphoteric surfactant may comprise N, N-dimethyldodecylamine N-oxide (NNDNO).

In order to accomplish the above object, the transparent conductive polymer thin film according to the second embodiment of the present invention is characterized by comprising 100 parts by weight of PEDOT: PSS (poly (3,4-ethylenedioxythiophene): polystyrene sulfonate) And 0.1 to 2 parts by weight of a surfactant.

According to another aspect of the present invention, there is provided a transparent electrode comprising: a substrate; And a transparent conductive polymer thin film formed on the substrate, wherein the transparent conductive polymer thin film has an ionic liquid of 0.1 to 2 parts by weight per 100 parts by weight of poly (3,4-ethylenedioxythiophene) (PEDOT: PSS) And 0.1 to 2 parts by weight of a surfactant.

The substrate may include at least one of polydimethylsiloxane (PDMS), silicone rubber, styrene ethylene butylene styrene (SEBS), and polyimide (PI).

The thickness of the thin film may be 100 to 500 nm.

The method for manufacturing a transparent electrode according to a fourth embodiment of the present invention for achieving the above object is characterized by comprising the steps of: (a) preparing a transparent electrode by ion-implanting 100 parts by weight of PEDOT: poly (3,4-ethylenedioxythiophene) 0.1 to 2 parts by weight of a liquid and 0.1 to 2 parts by weight of a surfactant; (b) applying the polymer composition onto a substrate; And (c) thermally treating the resultant of step (c) to form a transparent conductive polymer thin film formed on the substrate.

The polymer composition may be applied in a thickness of 100 to 500 nm.

The heat treatment may be performed at 100 to 150 ° C for 5 to 120 minutes.

The application may be carried out by spin coating, roll coating, spray coating, dip coating, flow coating, doctor blade and dispensing, inkjet printing, Printing may be performed by a printing method, a pad printing method, a gravure printing method, a flexography printing method, a stencil printing method, an imprinting method, a xerography method or a lithography method.

According to the present invention, by adding a surfactant to a thin film having both high conductivity and high stretchability, a thin film can be formed on various elastic substrates and can be used as a conductive thin film for a stressable electronic device.

Also, the transparent conductive polymer thin film according to the present invention can control the conductivity and stretchability of the thin film depending on the concentration and kind of ionic liquid, kind of surfactant, and kind of substrate.

In addition, the transparent electrode based on the transparent conductive polymer thin film can be used alone or in the upper transparent electrode and the lower transparent electrode of the device, and has a higher price competitiveness than the conventional metal and carbon nanomaterial-based stretchable conductive material It is expected.

1 is a graph showing the initial electrical conductivity and the maximum tensile strain of a conductive polymer (PEDOT: PSS) into which additives such as an elastomer, a surfactant, a plasticizer, and a soft polymer are introduced.
Fig. 2 shows changes in electrical conductivity (a) and elongation (b) of PEDOT: PSS (None: no additives) and EMIM TCB + PEDOT: PSS thin films.
3 is a cross-sectional view of a transparent electrode using a transparent conductive polymer thin film according to the present invention.
Fig. 4 shows changes in electric conductivity (a) and resistance-tensile strain characteristics (b) of a thin film depending on the kind of an ionic liquid.
FIG. 5 shows changes in the electric conductivity (a) and the resistance-tensile strain characteristics (b) of the thin film depending on the concentration of the EMIN TCB ionic liquid.
6 shows an optical microscope image (d) of a thin film according to the modification of PEDOT: PSS and 1 part by weight EMIM TCB + PEDOT: PSS, a SEM image (e) of a thin film after being stretched by 40% strain, (F) shown.
Fig. 7 shows changes in the electric conductivity (a) and the resistance-tensile strain characteristics (b) of the thin film with the addition of the ionic liquid / surfactant mixture.
8 shows changes in the resistance-tensile strain characteristics of the thin film with the concentration of the NNDNO surfactant.
Fig. 9 shows changes in electric conductivity (a) and resistance-tensile strain characteristics (b) of a thin film depending on the type of surfactant.
10 shows changes in resistance-tensile strain characteristics of the thin film depending on the type of the substrate.
11 shows changes in resistance-curvature radial deformation and bending characteristics of a thin film formed on a PI substrate.
12 shows the change in resistance-tensile strain characteristics of a thin film formed on a PDMS substrate and a SEBS substrate based on a combination of EMIM TCM and NNDNO, ENHIM TCB and NNDNO.
13 is a photograph (a) of an ACEL device using an EMIM TCB + PEDOT: PSS thin film as an upper electrode and a lower electrode, a cross-sectional view (b) of the ACEL device, an electroluminescence spectrum centered at 452 nm (F), 0 to 10% strain, 0 to 20% strain, 0 (strain), 0 to 20% strain, ~ 30% strain, 0 ~ 40% Average luminescence (g) of the device with strain.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, a polymer composition according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, a transparent conductive polymer thin film having excellent conductivity and stretchability, and a transparent electrode using the same will be described in detail.

The polymer composition according to the present invention comprises 0.1 to 2 parts by weight of an ionic liquid and 0.1 to 2 parts by weight of a surfactant based on 100 parts by weight of PEDOT: PSS (poly (3,4-ethylenedioxythiophene): polystyrene sulfonate).

Details related to PEDOT: PSS, ionic liquids and surfactants are explained in detail in transparent conductive polymer thin films.

The transparent conductive polymer thin film according to the present invention is a polymer comprising 0.1 to 2 parts by weight of an ionic liquid and 0.1 to 2 parts by weight of a surfactant per 100 parts by weight of PEDOT: PSS (poly (3,4-ethylenedioxythiophene): polystyrene sulfonate) It is a cured product of the composition.

PEDOT: PSS is a conductive polymer material having high thermal and chemical stability, excellent transparency in a visible light region, and high water-dispersibility, enabling a solution process to be environmentally friendly. In addition, since the dispersibility is excellent, it is easy to form a uniform thin film when forming a coating.

The PEDOT: PSS is represented by the following structural formula 1.

[Structural formula 1]

The ionic liquid means a salt (a pair of a cation and an anion) present in a liquid state at a temperature of 100 ° C or lower. The ionic liquid serves as an intermediary for increasing conductivity and stretchability through induction of the structure in the thin film. By adding various types of ionic liquids to PEDOT: PSS, it is possible to produce conductive composite materials having both high conductivity and high stretchability. Fig. 2 shows changes in electrical conductivity (a) and elongation (b) of PEDOT: PSS (None: no additives) and EMIM TCB + PEDOT: PSS thin films. 2 (a) and 2 (b), when EMIM TCB, which is an ionic liquid, is added to PEDOT: PSS, the electric conductivity rapidly increases from 1 S / cm to 1000 S / cm or more, and the maximum tensile strain is 5 % To 27%. Also, the modulus of elasticity was reduced to about 15 times or less. From these results, it can be predicted that PEDOT: PSS thin film doped with ionic liquid can be used as a conductive thin film for stressable electronic devices based on excellent electrical and mechanical properties.

The ionic liquid may be composed of a combination of a cation selected from the imidazolium-based cation or non-aromatic cation and an anion selected from an aromatic anion, a non-aromatic anion, or a sulfonic acid anion.

Specifically, the ionic liquid may be represented by the following Structural Formula 2 to Structural Formula 23. EMIM is 1-ethyl-3-methylimidazolium in the following Structural Formulas 2 to 23, BMIM is 1-butyl-3-methylimidazolium, 3-methylimidazolium, HMIM is 1-hydroxyethyl-3-methylimidazolium, EHIM is 1-ethyl-3-hydroxyimidazolium )to be.

For example, the ionic liquid may include EHIM TCB (1-ethyl-3-hydroxy-imidazolium tetracyanoborate), which is a combination of imidazolium cations containing a hydroxy group and nonaromatic anions.

The ionic liquid is preferably contained in an amount of 0.1 to 2 parts by weight based on 100 parts by weight of the PEDOT: PSS. When the content of the ionic liquid is less than 0.1 part by weight, it is difficult to expect an increase in the conductivity and stretchability of the thin film as the concentration becomes too low. On the other hand, when the amount is more than 2 parts by weight, the polymer composition may have a high viscosity and a low dispersion stability, so that it may be difficult to form a uniform thin film having a smooth surface at the time of coating.

The surfactant serves to increase the wettability of the polymer composition.

Since most elastic substrates having stretchability are not hydrophilic and coating of the aqueous solution is not easy, it is preferable to include a surfactant in the polymer composition in order to form the transparent conductive polymer thin film on the elastic substrate. Accordingly, a transparent conductive polymer thin film having excellent conductivity and stretchability can be prepared using only a polymer composition containing a surfactant without needing to separately surface-treat the substrate.

The surfactant may include at least one of a surfactant containing ethylene oxide in the main chain, a surfactant containing a fluorine group in the main chain, an anionic surfactant and an amphoteric surfactant.

Specifically, the surfactant may be represented by the following formulas [24] to [46]. In the following Structural Formula 24 to Structural Formula 39, n, x, y, and z are each independently an integer of 1 to 100.

For example, the surfactant may comprise the amphoteric surfactant N, N-dimethyldodecylamine N-oxide (NNDNO).

The surfactant is preferably included in an amount of 0.1 to 2 parts by weight based on 100 parts by weight of the PEDOT: PSS. When the content of the surfactant is less than 0.1 part by weight, it is difficult to expect the effect of increasing the wettability of the polymer composition as the concentration becomes too low. On the other hand, when the amount of the surfactant is more than 2 parts by weight, the dispersion stability of the ionic liquid, the surfactant, and the conductive polymer mixed solution is impaired.

3 is a cross-sectional view of a transparent electrode using a transparent conductive polymer thin film according to the present invention. Referring to FIG. 3, the transparent electrode according to the present invention includes a substrate 10 and a transparent conductive polymer thin film 20 formed on the substrate.

The transparent electrode means an electrically conductive electrode, and is an electrically conductive film capable of transmitting light including visible light.

The substrate is for supporting the transparent conductive polymer thin film. It is preferable that the substrate is made of a material having elasticity so as to be applied to a stretchable device capable of freely increasing or decreasing a shape. The substrate may be formed of, for example, a material including at least one of polydimethylsiloxane (PDMS), silicone rubber synthesized by a platinum catalyst, styrene ethylene butylene styrene (SEBS), and polyimide (PI).

Wherein the transparent conductive polymer thin film comprises 0.1 to 2 parts by weight of an ionic liquid and 0.1 to 2 parts by weight of a surfactant based on 100 parts by weight of poly (3,4-ethylenedioxythiophene) (PEDOT: PSS) It is cargo.

The ionic liquid and the surfactant are as described above.

The thickness of the thin film may be 100 to 500 nm. By satisfying the range, the transparent conductive polymer thin film having high conductivity and high stretchability and excellent transparency in the visible region can be produced.

As described above, the present invention provides a polymer composition comprising 0.1 to 2 parts by weight of a surfactant added to a composite material containing 0.1 to 2 parts by weight of an ionic liquid per 100 parts by weight of PEDOT: PSS, The transparent conductive polymer thin film can be formed on the elastic substrate.

A method of manufacturing a transparent electrode according to the present invention is as follows.

First, a polymer composition comprising 0.1 to 2 parts by weight of an ionic liquid and 0.1 to 2 parts by weight of a surfactant is prepared per 100 parts by weight of PEDOT: PSS (poly (3,4-ethylenedioxythiophene): polystyrene sulfonate). The above polymer composition is as described above.

 Subsequently, the polymer composition is applied onto the substrate. At this time, the polymer composition can be applied so that the thickness of the coating layer is approximately 100 to 500 nm.

The application may be carried out by spin coating, roll coating, spray coating, dip coating, flow coating, doctor blade and dispensing, inkjet printing, Printing may be performed by a printing method, a pad printing method, a gravure printing method, a flexography printing method, a stencil printing method, an imprinting method, a xerography method or a lithography method.

Next, the resultant is heat-treated to prepare a transparent conductive polymer thin film formed on the substrate.

The heat treatment may be performed at 100 to 150 ° C for 5 to 120 minutes. If the temperature of the heat treatment is less than 100 占 폚, the polymer composition may be insufficient for curing, and if it exceeds 150 占 폚, the electrical characteristics may be deteriorated due to decomposition of the conductive polymer.

The method of manufacturing a transparent electrode according to the present invention can be applied to a stressable electronic device through processes such as dry lamination and dry transfer in addition to coating and heat treatment.

The transparent conductive polymer thin film according to the present invention and the transparent electrode using the transparent conductive polymer thin film will now be described in detail with reference to the drawings.

In the following drawings, ENHIM refers to EHIM. The wt% shown in the following drawings is expressed as 1 part by weight (1 wt%) and 1.5 parts by weight (1.5 wt%), calculated as parts by weight.

The physical property measurement method in FIGS. 4 to 10 is as follows.

The film thickness was measured using a Surfcorder ET-3000 profile meter. The electrical conductivity was measured by connecting a 0.05 mm diameter copper wire to the sample via EGaIn. Stress-strain analysis was performed at 24 ° C and 50% relative humidity using a TXA Texture analyzer (yeoungjin corp.) With a load of 30 kg. The strain rate was set at 0.15 mm · s-1 and the film was stretched until it broke. Optical microscope photographs were observed with a Zeiss Axio Scope.A1 microscope. SEM images were observed with a Quanta 200FEG field emission SEM (FEI corp) operating at 10 kV.

Fig. 4 shows changes in electric conductivity (a) and resistance-tensile strain characteristics (b) of a thin film depending on the kind of an ionic liquid. 1 part by weight of an ionic liquid was added to PEDOT: PSS (Heraeus) and 1 part by weight of FS-31 (Dupont, formula 31) was further added as a surfactant to the PDMS substrate by spin coating to a thickness of 200 nm And then heat-treated at 130 ° C for 15 minutes.

Referring to FIG. 4, the electrical conductivities were different depending on the type of the ionic liquid. EMIM TCM and ENHIM TCB show excellent electrical conductivity as well as excellent stretchability. In particular, ENHIM TCB showed a 30% increase in elasticity compared to EMIM TCM.

FIG. 5 shows changes in the electric conductivity (a) and the resistance-tensile strain characteristics (b) of the thin film depending on the concentration of the EMIN TCB ionic liquid. The thin film was prepared by applying EMIM TCB to PEDOT: PSS and further adding 1 part by weight of FS-31 surfactant to the PDMS substrate by spin coating to a thickness of 200 nm, followed by heat treatment at 130 ° C for 15 minutes . Electrical conductivity and stretchability were influenced by the concentration of ionic liquid. As the concentration of ionic liquid increased, the electrical conductivity of PEDOT: PSS increased and the durability of electrical properties to tensile strain also increased.

From these results, it is preferable that the polymer composition contains 0.1 to 2 parts by weight, more preferably 1.0 to 1.5 parts by weight, of the ionic liquid relative to 100 parts by weight of PEDOT: PSS. However, when the ionic liquid is added in an amount of 2 parts by weight or more, it is difficult to uniformly coat the polymer composition due to the high viscosity state and low dispersion stability of the polymer composition.

6 shows an optical microscope image (d) of a thin film according to the modification of PEDOT: PSS and 1 part by weight EMIM TCB + PEDOT: PSS, a SEM image (e) of a thin film after being stretched by 40% strain, (F) shown. EMIM TCB + PEDOT: PSS thin film was prepared by adding 1 part by weight of EMIM TCB to PEDOT: PSS and adding 1 part by weight of FS-31 as a surface active agent to the PDMS substrate by spin coating to a thickness of 200 nm, Lt; RTI ID = 0.0 > 130 C < / RTI > for 15 minutes.

As shown in (d), a small crack was observed in the original PEDOT: PSS film even without deformation, and the crack tended to become larger and thicker as the strain increased to 20% and 40%, respectively. This crack shows a degree of fragility of the PEDOT: PSS thin film. On the other hand, the EMIM TCB + PEDOT: PSS thin film was hardly cracked even at 40% strain. (e), when a PEDOT: PSS thin film was subjected to 40% deformation, a crack having a width of about 2 탆 was formed. On the other hand, under the same strain, the EMIM TCB + PEDOT: PSS film formed a very thin crack with a width of approximately 0.2 μm.

Therefore, it can be seen from the results (d) to (f) of FIG. 6 that the EMIM TCB + PEDOT: PSS thin film shows high elasticity.

Fig. 7 shows changes in the electric conductivity (a) and the resistance-tensile strain characteristics (b) of the thin film with the addition of the ionic liquid / surfactant mixture. The thin film was prepared by spin coating a solution of 1 part by weight of EMIM TCB in PEDOT: PSS and 1 part by weight of a surfactant on a PDMS substrate to a thickness of 200 nm, and then heat treating the resultant at 130 DEG C for 15 minutes.

The addition of FS-31 was maintained above 1000 S / cm without changing the electrical conductivity. Addition of Triton-X, N, N-Dimethyldodecylamine N-oxide (NNDNO) and Synperonic PE / P84 slightly reduced the electrical conductivity of the thin film, but most of them showed electrical conductivity of more than 700 S / cm. On the other hand, these three enhance the stretchability of the transparent electrode more than when FS-31 was added. In particular, the NNDNO surfactant exhibited the highest stretchability.

8 shows changes in the resistance-tensile strain characteristics of the thin film with the concentration of the NNDNO surfactant. The thin film was prepared by applying 1 part by weight of EMIM TCB to PEDOT: PSS and further adding NNDNO surfactant to the PDMS substrate by spin coating to a thickness of 200 nm, followed by heat treatment at 130 ° C for 15 minutes.

As the concentration of surfactant increases, the durability of electrical properties to tensile strain tends to increase.

From these results, it is preferable that the polymer composition contains 0.1 to 2 parts by weight, more preferably 1.0 to 1.5 parts by weight, of the surfactant based on 100 parts by weight of PEDOT: PSS. However, when the surfactant is added in an amount of 2 parts by weight or more, it is difficult to uniformly coat the polymer composition due to the high viscosity state and low dispersion stability of the polymer composition.

Fig. 9 shows changes in electric conductivity (a) and resistance-tensile strain characteristics (b) of a thin film depending on the type of surfactant. The thin film was prepared by spin coating a solution prepared by adding 1 part by weight of a surfactant to PEDOT: PSS to a thickness of 200 nm on a PDMS substrate, followed by heat treatment at 130 ° C for 15 minutes. When the electrical conductivity and the resistance-tensile strain characteristics of FS-31, Triton-X, Synperonic PE / P84 and NNDNO were measured after addition of PEDOT: PSS without ionic liquid, Conconductivity was increased, but the electrical conductivity did not increase for Synperonic PE / P84 and NNDNO. It was also confirmed that the enhancement of the stretchability of the PEDOT: PSS film was not induced by the addition of only the surfactant.

10 shows changes in resistance-tensile strain characteristics of the thin film depending on the type of the substrate. The thin film was prepared by spin coating a solution prepared by adding 1 part by weight of EMIM TCB to PEDOT: PSS and 1 part by weight of NNDNO to a substrate to a thickness of 200 nm, and then heat treating at 130 ° C for 15 minutes. It was confirmed that the stretchability of the conductive polymer thin film was also affected by the substrate type. In the case of PDMS and platinum-catalyzed silicon rubber, which are commonly used as elastic substrates, Ecoflex does not cause an electrical short-circuit even at 50% tensile strain. Styrene ethylene butylene styrene (SEBS) Thereby making it possible to produce a conductive polymer thin film having very excellent elasticity which does not appear.

Also, it has been confirmed that the polyimide (PI) exhibiting excellent mechanical strength as a typical flexible substrate has durability up to a tensile strain of about 30%, and electrical shorting is not induced.

11 shows changes in resistance-curvature radial deformation and bending characteristics of a thin film formed on a PI substrate. The thin film was prepared by spin coating a solution of 1 part by weight of EMIM TCB in PEDOT: PSS and 1 part by weight of NNDNO on a PI substrate by spin coating to a thickness of 200 nm, and then heat treating the resultant at 130 ° C for 15 minutes.

The change in resistance was not observed even at a radius of curvature of 0.5 to 3.5 mm, and it was confirmed that the electric characteristics were maintained even after 100,000 cycles of concave and convex bending with a radius of curvature of 2.5 mm.

12 shows the change in resistance-tensile strain characteristics of a thin film formed on a PDMS substrate and a SEBS substrate based on a combination of EMIM TCM and NNDNO, ENHIM TCB and NNDNO. The thin film was prepared by spin coating a solution prepared by adding 1.5 parts by weight of an ionic liquid to PEDOT: PSS and adding 1 part by weight of NNDNO to a substrate to a thickness of 200 nm, and then heat-treating at 130 ° C for 15 minutes.

12, the stretchability of the thin film on the SEBS substrate was superior to that of the PDMS substrate.

Finally, the highly flexible, highly conductive PEDOT: PSS thin film, which does not cause electrical shorts to more than 300% using ENHIM TCB, EMIM TCM, surfactant NNDNO, and SEBS substrate, .

13 is a photograph (a) of an ACEL device using an EMIM TCB + PEDOT: PSS thin film as an upper electrode and a lower electrode, a cross-sectional view (b) of the ACEL device, an electroluminescence spectrum centered at 452 nm (F), 0 to 10% strain, 0 to 20% strain, 0 (strain), 0 to 20% strain, ~ 30% strain, 0 ~ 40% Average luminescence (g) of the device with strain.

The ACEL device comprises a PDMS containing ZnS: Cu, a PEDOT: PSS / EMIM TCB thin film formed on both sides of the PDMS, and a PDMS formed on both sides of the thin film. PDMS containing ZnS: Cu contains ZnS: Cu powder and PDMS liquid at a weight ratio of 2: 1. This was spin-coated on the lower electrode at 2000 rpm for 120 seconds and then dried at 110 ° C for 40 minutes. Next, another layer of the PEDOT: PSS / EMIM TCB thin film was spin-coated on the PDMS active layer containing ZnS: Cu at 2000 rpm for 40 seconds and annealed at 110 ° C for 15 minutes. Finally, PDMS was encapsulated by spin coating and spinning at 500 rpm for 120 seconds and at 110 캜 for 40 minutes. The initial length of the ACEL device was 1 cm < ² > and the device was stretched at a draw speed of 0.13 mm < ^-1 > using a custom stretcher.

The luminance of the ACEL device was measured by connecting it to a DC-AC inverter purchased from Shanghai KPT Company using a PR650 spectrophotometer with a Keithley 2400 Source Measure Unit.

Referring to FIG. 13, (a) and (b) show the photograph and structure of the ACEL device having a stretchy and translucent state. The ACEL device was powered by a rectangular pulse function (pulse voltage of ± 110V and frequency of 1.5kHz) and exhibited excellent mechanical performance as shown in (c) to (g) and a deep blue luminescence. (d) and (e) show that, when the device is increased by 50%, the device is not deteriorated in function even if it is bent and twisted. As in (f) the strain increases from 0% to 50% of the luminance of the device was decreased slightly at 106cd / m ^-2 to 102cd / m ^-2. These results are in good agreement with the normalized resistance change of the thin film. In addition, the mechanical durability of ACEL was evaluated under repeated stretching cycles within a range in which the maximum strain increased from 10% to 40%. In a total of 80 stretching cycles, the device was found to have excellent elasticity by maintaining 90% of the luminance.

The transparent conductive polymer thin film based on PEDOT: PSS, an ionic liquid, and a surfactant obtained through the present invention can be formed on an elastic substrate and can be applied as a transparent electrode for a stressable electronic device. In addition, the transparent conductive polymer thin film may be used alone, or as an upper transparent electrode, a lower transparent electrode, and upper and lower transparent electrodes of the device in various structures. In particular, a transparent electrode coated with a thin film on a scalable substrate can be used as it is, but it is possible to use dry transfer and without a support.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It is to be understood that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

10: substrate
20: Transparent conductive polymer thin film

Claims (21)

0.1 to 2 parts by weight of an ionic liquid and 0.1 to 2 parts by weight of a surfactant based on 100 parts by weight of PEDOT: PSS (poly (3,4-ethylenedioxythiophene): polystyrene sulfonate).
The method according to claim 1,
Wherein the ionic liquid is composed of a combination of a cation selected from an imidazolium-based cation or a non-aromatic cation and an anion selected from an aromatic anion, a non-aromatic anion, or a sulfonic acid anion.
3. The method of claim 2,
Wherein the ionic liquid comprises a combination of an imidazolium-based cation and a non-aromatic anion.
The method according to claim 1,
Wherein said surfactant comprises at least one of a surfactant containing ethylene oxide in its main chain, a surfactant containing a fluorine group in its main chain, an anionic surfactant and an amphoteric surfactant.
5. The method of claim 4,
Wherein the amphoteric surfactant comprises N, N-dimethyldodecylamine N-oxide (NNDNO).
, 0.1 to 2 parts by weight of an ionic liquid and 0.1 to 2 parts by weight of a surfactant per 100 parts by weight of PEDOT: PSS (poly (3,4-ethylenedioxythiophene): polystyrene sulfonate). Conductive polymer thin film.
The method according to claim 6,
Wherein the ionic liquid comprises a combination of a cation selected from an imidazolium-based cation or a non-aromatic cation and an anion selected from an aromatic anion, a non-aromatic anion, or a sulfonic acid anion.
8. The method of claim 7,
Wherein the ionic liquid comprises a combination of an imidazolium-based cation and a non-aromatic anion.
The method according to claim 6,
Wherein the surfactant comprises at least one of a surfactant containing ethylene oxide in the main chain, a surfactant containing a fluorine group in the main chain, an anionic surfactant and an amphoteric surfactant.
10. The method of claim 9,
Wherein said amphoteric surfactant comprises N, N-dimethyldodecylamine N-oxide (NNDNO).
Board; And
And a transparent conductive polymer thin film formed on the substrate,
The transparent conductive polymer thin film
, 0.1 to 2 parts by weight of an ionic liquid and 0.1 to 2 parts by weight of a surfactant per 100 parts by weight of PEDOT: PSS (poly (3,4-ethylenedioxythiophene): polystyrene sulfonate). electrode.
12. The method of claim 11,
Wherein the substrate comprises at least one of polydimethylsiloxane (PDMS), silicone rubber, styrene ethylene butylene styrene (SEBS), and polyimide (PI).
12. The method of claim 11,
Wherein the ionic liquid comprises a combination of a cation selected from an imidazolium-based cation or a non-aromatic cation and an anion selected from an aromatic anion, a non-aromatic anion, or a sulfonic acid anion.
14. The method of claim 13,
Wherein the ionic liquid comprises a combination of an imidazolium-based cation and a non-aromatic anion.
12. The method of claim 11,
Wherein the surfactant comprises at least one of a surfactant containing ethylene oxide in the main chain, a surfactant containing a fluorine group in the main chain, an anionic surfactant and an amphoteric surfactant.
16. The method of claim 15,
Wherein the amphoteric surfactant comprises N, N-dimethyldodecylamine N-oxide (NNDNO).
12. The method of claim 11,
Wherein the thickness of the thin film is 100 to 500 nm.
(a) providing a polymer composition comprising 0.1 to 2 parts by weight of an ionic liquid and 0.1 to 2 parts by weight of a surfactant per 100 parts by weight of PEDOT: PSS (poly (3,4-ethylenedioxythiophene): polystyrene sulfonate);
(b) applying the polymer composition onto a substrate; And
(c) heat-treating the resultant of step (c) to form a transparent conductive polymer thin film on the substrate.
19. The method of claim 18,
Wherein the polymer composition is applied in a thickness of 100 to 500 nm.
19. The method of claim 18,
Wherein the heat treatment is performed at 100 to 150 DEG C for 5 to 120 minutes.
19. The method of claim 18,
The application may be carried out by spin coating, roll coating, spray coating, dip coating, flow coating, doctor blade and dispensing, inkjet printing, Characterized in that the method is performed by a printing method, a pad printing method, a gravure printing method, a flexography printing method, a stencil printing method, an imprinting method, a xerography method or a lithography method. Way.

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