KR20180124405A - Flexible transparent electrode and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a flexible transparent electrode and a manufacturing method thereof. The manufacturing method for a flexible transparent electrode comprises the steps of: mixing a first solution including a polymer having an amine group and a second solution including a silver ion to prepare a mixed solution; scanning the mixed solution with a laser; and forming an organic/inorganic hybrid layer including a silver nanoparticle and the polymer having the amine group by coating the mixed solution scanned with the laser on a substrate. Therefore, the flexible transparent electrode has excellent flexibility which does not generate a crack in the electrode due to a bending operation, has economic feasibility, has improved electrical characteristics of the electrode, has increased light transmittance, and has simplified manufacturing processes.

Description

TECHNICAL FIELD [0001] The present invention relates to a flexible transparent electrode and a manufacturing method thereof,

The present invention relates to an electrode, and more particularly, to a flexible transparent electrode and a manufacturing method thereof.

The transparent conductive film means a thin film having high transparency to light and electricity. The transparent conductive film can be used as a power source for a liquid crystal display, an electrochromic display (ECD), an organic electroluminescence device, a solar cell, a plasma display panel, an electronic paper, And is widely used as a common electrode and a pixel electrode. In recent years, there has been an increasing demand for a transparent conductive film having excellent transparency and a low resistivity, as a large-sized device is developed and a very fine pitch device is developed.

Since the material used for the transparent conductive film has a light transmittance of about 80% in a visible light region (400 nm to 700 nm), it should be transparent to human eyes and exhibit good electrical conductivity. In addition, since the optical bandgap is about 3.5 eV, it is preferable that the ultraviolet region is all transmitted, the reflectance is high in the infrared region, and the characteristic is suitable for etching.

Conventionally, a transparent conductive oxide (TCO) material was used as the transparent conductive film material. Currently, TCO material types used industrially include In ₂ O ₃ , ZnO, and SnO ₂ . Their common feature is that the bandgap is 3.3 eV, which has a higher bandgap than visible light, so that absorption in the visible light region does not occur. In addition, it is an n-type conductive material, has good bonding strength with glass, and is excellent in chemical resistance and abrasion resistance.

On the other hand, an organic light emitting display (OLED) having flexibility is attracting attention as a next generation display, and the OLED also uses the TCO material as an electrode material material.

Korean Patent Publication No. 10-1391510 (hereinafter referred to as "prior patent") relates to a multilayer transparent electrode element having metal nanowires, which comprises a lower transparent electrode layer formed on the upper surface of a transparent flexible substrate, A metal nanowire layer formed on the upper surface of the metal nanowire layer and an upper transparent electrode layer formed on the upper surface of the metal nanowire layer to improve the adhesion between the transparent flexible substrate and the metal nanowire layer and to reduce the surface roughness of the metal nanowire layer .

The upper transparent electrode layer of the prior art is applied to any one of ITO, ZTO, IZO, IZTO, GZO, AZO, NbTiO ₂ , FTO, ATO and BZO. The materials include the TCO material described above. However, in the case of TCO materials, the material cost is high, and when applied to a device having flexibility, there are problems such as device deterioration due to diffusion of In, high reducing property of In and Sn under hydrogen plasma, and accompanying instability of device. In addition, when TCO is deposited on a flexible substrate (PES, PC, PET, PEN, etc.), the TCO thin film is subjected to bending due to cracking or the like, There are disadvantages.

In addition, the prior art is disadvantageous in that the process is complicated because a solution process, a sputtering deposition process, and an opposite target sputtering process have to be performed in the production of a transparent electrode.

Patent Document 1: Korean Patent Publication No. 10-1391510 (Publication Date: May 05, 2014, entitled: Multilayer Transparent Electrode Device Having Metal Nanowire)

SUMMARY OF THE INVENTION An aspect of the present invention is to provide a flexible transparent electrode which has excellent flexibility and is economical so as not to generate cracks in electrodes due to bending work and can improve the electrical characteristics and light transmittance of electrodes. It is an object to provide an electrode.

Another aspect of the present invention is to provide a flexible transparent electrode capable of improving the electrical characteristics and light transmittance of the electrode and simplifying the process, which is excellent in flexibility, free from cracks in the electrode due to the bending operation, There is another purpose in providing a manufacturing method.

In order to solve the above-described problems, one aspect of the present invention provides a method of manufacturing a flexible transparent electrode. The flexible transparent electrode may be prepared by mixing a first solution containing a polymer having an amine group and a second solution containing silver ions to prepare a mixed solution, scanning the mixed solution with a laser, And coating the mixed solution on which the laser is scanned on the substrate to form an organic hybrid layer including a polymer having an amine group and silver nanoparticles.

Also, the first solution may contain 5 to 10 wt% of polyethyleneimine and the second solution may include 1.5 to 5 wt% of AgNO ₃ .

In addition, the step of scanning the laser may be performed for a time of 1 to 10 ms with an intensity of 50 to 200 mW.

In addition, in the step of preparing the mixed solution, the silver ions are uniformly arranged by the electrostatic attraction of the amine group and the silver ion, and in the step of scanning the laser, silver ions As the silver nanoparticles are reduced, the organic hybrid layer including the polymer having the amine group and the silver nanoparticles can be formed.

The method may further include forming an antireflection layer including a conductive polymer on the organic hybrid layer after forming the organic hybrid layer.

Another aspect of the present invention provides a flexible transparent electrode. Wherein the flexible transparent electrode comprises a substrate and an organic hybrid coating layer disposed on the substrate and comprising polymer and nanoparticles having amine groups, wherein the organic hybrid coating layer comprises a first solution comprising a polymer having an amine group, Ions is mixed with a solution prepared by scanning a laser in a mixed solution.

According to the flexible transparent electrode of the present invention, it is possible to obtain excellent flexibility that does not cause cracks in the electrode due to the bending operation, is economical, and has an effect of improving the electrical characteristics and light transmittance of the electrode. Further, according to the flexible transparent electrode manufacturing method of the present invention, it is possible to provide a flexible transparent electrode having excellent flexibility that does not cause cracking in the electrode due to the bending operation, is economical, improves the electrical characteristics and light transmittance of the electrode, .

1 is a flowchart showing a method of manufacturing a flexible transparent electrode according to an embodiment of the present invention.
2 is an image showing an arrangement state of silver ions according to an embodiment of the present invention.
3 is a cross-sectional view of a flexible transparent electrode according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

The present invention will now be described more specifically with reference to the following examples. However, the following examples should not be construed as limiting the scope of the present invention, and should be construed to facilitate understanding of the present invention.

1 is a flowchart showing a method of manufacturing a flexible transparent electrode according to an embodiment of the present invention.

Referring to FIG. 1, a method of manufacturing a flexible transparent electrode according to an exemplary embodiment of the present invention includes preparing a mixed solution by mixing a first solution containing a polymer having an amine group and a second solution containing silver ions (S300) of scanning a laser with the mixed solution, forming a hybrid organic-inorganic hybrid layer containing an amine group-containing polymer and silver nanoparticles by coating the mixed solution on which the laser is scanned on the substrate (S300 ).

The step of preparing the mixed solution (S100) will be described.

The mixed solution includes a first solution containing a polymer having an amine group and a second solution containing silver ions.

The first solution comprises a polymer having an amine group. The polymer having an amine group has an anionic property in an aqueous solution as it has an amine group. The polymer having an amine group may include at least one selected from the group consisting of polyethyleneimine (PEI), polylysine PLS, and polyallylamine (PAA).

When the polymer having an amine group is a polyethyleneimine, the first solution may be prepared as a solution having a concentration of 5 to 15% by weight by performing the spin coating of the polyethyleneimine for 1 to 20 hours. If the spin-coating time is less than 1 hour, the solution may be difficult to form. If the spin-coating time is more than 20 hours, the process time becomes long and the solution formation becomes difficult. If the concentration of the polyethyleneimine solution is less than 5 wt%, the distribution of silver ions may be uneven. If the concentration of the polyethyleneimine solution is more than 15 wt%, the solubility may be decreased and the effect of improving the flexibility due to the increase of the concentration of the polyethyleneimine . At this time, the solvent to be used is not limited as long as it is a solvent capable of dissolving a polymer having an amine group.

The second solution is a solution containing silver ions, and may be an aqueous solution containing AgNO ₃ . The solvent which can be used herein may be any solvent which can dissolve the silver ion-containing material, and may be, for example, water (H ₂ O).

When the second solution is an aqueous solution containing AgNO ₃ may include AgNO ₃ to 1.5 to a concentration of 5.0% by weight. When the concentration of AgNO ₃ is less than 1.5% by weight, the improvement of the electrical characteristics due to the inclusion of silver nanoparticles may be insignificant. If the concentration exceeds 5.0% by weight, the improvement of electrical characteristics may be insignificant due to the increase in concentration.

2 is an image showing an arrangement state of silver ions according to an embodiment of the present invention.

Referring to FIG. 2, the amine group is attracted to each other by the electrostatic attraction of the amine group and the silver ion, which are anionic in the polymer. Thus, the silver ions are uniformly distributed in the mixed solution in which the first solution and the second solution are mixed.

Next, a description will be given of the step (S200) of scanning the laser with the mixed solution.

As the laser is scanned on the mixed solution, the solvent molecules in the mixed solution are excited into a radical state capable of easily emitting electrons by two-photon absorption phenomenon. Thus, electrons generated from the solvent are reduced to silver nanoparticles by receiving silver ions. The reduced silver nanoparticles react with the amine group of the polymer containing the amine group to form coordination bonds.

The step of scanning the laser may be performed for 1 to 10 MS hours of intensity from 50 to 200 mW. If the intensity of the laser is less than 50 mW, the silver ions may not be reduced and the generation rate of silver nanoparticles may be lowered. If the laser intensity is more than 200 mW, the size of the silver nanoparticles may increase and the silver nanoparticles may aggregate. When the laser scanning time is less than 1 ms (millisecond), silver ions are not reduced and the generation rate of silver nanoparticles may be lowered. If the laser scanning time exceeds 10 ms, the size of the silver nanoparticles increases, It can be difficult.

Next, a description will be given of a step (S300) of forming an organic hybrid layer including a polymer having amine groups and silver nanoparticles by coating the mixed solution on which the laser is scanned on the substrate.

The substrate may be a flexible substrate and may be a flexible substrate such as a polyimide (PI), a polyethersulfone (PES), a polyacrylate (PAR), a polyetherimide (PEI), a polyethylene naphthalate naphthalate (PEN), polyethyleneterephthalate (PET), polyphenylene sulfide (PPS), polyarylate, polycarbonate (PC), cellulose triacetate , And cellulose acetate propionate (CAP).

The substrate may be coated on the substrate by a spin coating method, a roll coating method, a spray coating method, a flow coating method, an inkjet printing method, a nozzle printing method, a dip coating method, an electrophoretic deposition method, a tape casting method, It is possible to coat the laser-scanned mixed solution by performing a pad printing method, a doctor blade coating method, a gravure printing method, a gravure offset printing method, or a Langmuir-Blogett method .

The organic hybrid layer thus formed is formed in a state in which a polymer having amine groups and silver nanoparticles are coordinated to each other through a simple solution process. Specifically, the process is simplified and the thickness of the electrode can be made thinner as compared with the case where the polymer layer including a polymer having an amine group and the metal layer including silver nanoparticles are formed in a multilayered form, It is possible to achieve high integration and miniaturization. In addition, since the silver nanoparticles are uniformly arranged by the polymer having an amine group in an ionic state before reduction, uniform electrical characteristics are exhibited throughout the organic hybrid layer, and thus the lifetime of the organic electronic device may be prolonged. Further, since it is a single layer structure, it is possible to prevent the electrical and mechanical properties from deteriorating due to the interlayer interfacial property which occurs when the multilayer structure is used.

The method may further include forming an antireflection layer including a conductive polymer on the organic hybrid layer after forming the organic hybrid layer. When the antireflection layer is further formed, the light transmittance and sheet resistance of the electrode can be improved. The conductive polymer may be at least one selected from the group consisting of polyaniline, polythiophene, polyethylenedioxythiophene (PEDOT), polyimide, polystyrenesulfonate (PSS), polypyrrole, polyacetylene Poly (p-phenylene sulfide), poly (p-phenylene sulfide), poly (p-phenylene vinylene) (phenylenevinylene)], polythiophene poly (thienylene vinylene), and poly (3,4-ethylenedioxythiophene) poly (styrene sulfonate) [Poly -ethylenedioxythiophene poly (styrenesulfonate), (PEDOT: PSS)]. The antireflection layer may be formed by a method such as spin coating, roll coating, spray coating, flow coating, inkjet printing, nozzle printing, dip coating, electrophoretic deposition, A doctor blade coating method, a gravure printing method, a gravure offset printing method, or a Langmuir-Blogett method.

3 is a cross-sectional view of a flexible transparent electrode according to an embodiment of the present invention.

3, the flexible transparent electrode according to an exemplary embodiment of the present invention includes a substrate 100 and the organic-inorganic hybrid coating layer 200 disposed on the substrate 100 and including polymer and nano- . Hereinafter, the substrate 100 and the organic / inorganic hybrid coating layer 200 will be described in detail.

In summary, the flexible transparent electrode according to an embodiment of the present invention can form an organic hybrid layer by a simple solution process on a substrate, can be applied to a flexible device, and can produce an electrode with excellent light transmittance have.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

100: substrate 200: organic hybrid layer

Claims (6)

Preparing a mixed solution by mixing a first solution containing a polymer having an amine group and a second solution containing silver ions;
Scanning the laser with the mixed solution; And
And coating the mixture solution on which the laser is scanned on the substrate to form an organic hybrid layer including a polymer having an amine group and silver nanoparticles. The method according to claim 1,
Wherein the first solution comprises 5 to 10 wt% of polyethyleneimine and the second solution comprises 1.5 to 5.0 wt% of AgNO ₃ . The method according to claim 1,
Wherein the laser is scanned at an intensity of 50 to 200 mW for 1 to 10 ms. The method according to claim 1,
In the step of preparing the mixed solution, the silver ions are uniformly arranged by the electrostatic attraction between the amine group and the silver ion, and in the step of scanning the laser, the silver ions in the mixed solution are reduced And the organic hybrid layer is formed as silver nanoparticles are generated. The method according to claim 1,
After the step of forming the organic-inorganic hybrid layer,
Further comprising the step of forming an antireflection layer containing a conductive polymer on the organic / inorganic hybrid layer. Board; And
And an organic hybrid coating layer disposed on the substrate and comprising an amine group-containing polymer and silver nanoparticles coordinated to each other.

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