KR102677586B1 - electrode for low resistance-high current and fabrication method for the same - Google Patents

Abstract

An electrode for low resistance and high current is disclosed. The low-resistance-high-current electrode of the present invention includes a base material; A hard coating layer disposed on the substrate; A metal layer disposed on the hard coating layer; Conductive capping layers disposed on top and bottom of the metal layer, respectively; and a conductive functional layer disposed on top of the conductive capping layer disposed on the metal layer.

Description

Low resistance-high current electrode and manufacturing method thereof {electrode for low resistance-high current and fabrication method for the same}

The present invention relates to a low-resistance-high-current electrode and a method of manufacturing the same.

Smart window products are windows that use PDLC (Polymer Dispersed Liquid Crystal), EC (Electrochromic), and EL (Electroluminescence) to perform various functions such as controlling light transmission, heat shielding, and insulation.

In particular, active smart windows are a technology that electronically changes the optical and thermal properties of windows, and conventional ITO electrodes were mainly applied. However, ITO electrodes are difficult to apply to foldable and rollable products due to their low flexibility, which limits their application as flexible smart window products, and are difficult to drive at low voltage, leading to low energy efficiency and stability. there is.

Meanwhile, silver (Ag) is an excellent material as a flexible transparent electrode due to its high visible light transmittance and very low specific resistance in thin films, but it is difficult to commercialize due to durability problems such as oxidation. In order to use silver (Ag), measures are needed to effectively prevent oxidation of silver and suppress migration, but at the same time, there is a limitation that it must be made of conductive materials for connection as an electrode.

The technical problem to be solved by the present invention is to provide a low-resistance-high-current electrode with excellent flexibility and a manufacturing method thereof that realizes low resistance by forming an electrode with a multi-layer structure, improves current flow by facilitating the movement of charges, and provides excellent flexibility. It is done.

In order to solve the above technical problem, an electrode for low resistance and high current according to an embodiment of the present invention includes a base material; A hard coating layer disposed on the substrate; A metal layer disposed on the hard coating layer; Conductive capping layers disposed on top and bottom of the metal layer, respectively; and a conductive functional layer disposed on top of the conductive capping layer disposed on the metal layer; wherein the composition forming the hard coating layer includes a photocurable oligomer, and the conductive capping layer is one of ITO, IZO, ZIST, and IZTO. It includes any one selected, and the conductive functional layer may include any one selected from ITO, IZO, ZIST, and IZTO.

In one embodiment of the present invention, it may be an alloy containing silver (Ag) as a main component and to which at least one of niobium (Nb) and gold (Au) is added.

In one embodiment of the present invention, an index matching layer is formed between the substrate and the hard coating layer and the medium and thickness are selected to determine the transmittance of the entire film.

In one embodiment of the present invention, the metal layer may include 89.5 at% to 96.5 at% of silver (Ag), 0.5 at% to 1.5 at% of niobium (Nb), and 3.0 at% to 9.0 at% of gold (Au). there is.

In one embodiment of the present invention, the substrate is formed to 125 nm using PET material, the hard coating layer is formed to 3 μm using an acrylate-based material, and the conductive capping layer is formed to 10 nm using IZO. The metal layer can be formed to be 10 nm thick, and the conductive functional layer can be formed to be 20 nm thick using ITO.

The present invention achieves low resistance by forming an electrode with a multi-layer structure, allows high currents to be applied, and has the effect of ensuring flexibility.

Figure 1 shows a low-resistance-high-current electrode according to an embodiment of the present invention.
Figure 2 shows a method of manufacturing a low-resistance-high-current electrode according to an embodiment of the present invention.

Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all transformations, equivalents, and substitutes included in the spirit and technical scope of the present invention.

In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 shows a low-resistance-high-current electrode 100 according to an embodiment of the present invention.

Referring to FIG. 1, the low-resistance-high-current electrode 100 according to an embodiment of the present invention includes a substrate 110, a hard coating layer 120, an index matching layer 130, and a conductive capping layer 140 and 160. , includes a metal layer 150 and a conductive functional layer 170.

The substrate 110 may include an inorganic material or an organic material.

The inorganic material may be any one or a combination of glass, quartz, Al2O3, SiC, Si, GaAs, and InP, but is not limited thereto.

Organic substances include Kapton foil, polyimide (PI), polyethersulfone (PES), polyacrylate (PAR), polyetherimide (PEI), and polyethylene naphthalate (PEN). , polyethyleneterephthalate (PET), polyphenylene sulfide (PPS), polyarylate, polycarbonate (PC), cellulose triacetate (CTA), cellulose acetate propio It may be selected from cellulose acetate propionate (CAP), but is not limited thereto.

However, since the present invention is intended to achieve low resistance and high light transmittance, it is preferable that the substrate 110 is selected in consideration of appropriate thickness, material (index), etc.

The substrate 110 in one embodiment of the present invention includes polyethylene terephthalate (PET).

A hard coating layer 120 may be formed on the substrate 110.

The hard coating layer 120 may be formed from a photocurable type composition. A photocurable type composition refers to a composition in which the curing process is induced by irradiation of electromagnetic waves. Electromagnetic waves include microwaves, infrared (IR), ultraviolet (UV), X-rays, γ-rays or α-particle beams, proton beams, neutron beams and electron beams ( It is used as a general term for particle beams such as electron beams.

The composition forming the hard coating layer 120 may include a photocurable oligomer. As the photocurable oligomer, oligomer components used in the production of photocurable (eg, UV curable) compositions in the art can be used without limitation. For example, the oligomer includes urethane acrylate obtained by reacting polyisocyanate having two or more isocyanate groups in the molecule and hydroxyalkyl (meth)acrylate; Ester-based acrylate obtained by dehydration condensation reaction of polyester polyol and (meth)acrylic acid; Ester-based urethane acrylate obtained by reacting an ester-based urethane resin obtained by reacting polyester polyol and polyisocyanate with hydroxyalkyl acrylate; Ether-based acrylates such as polyalkylene glycol di(meth)acrylate; Ether-based urethane acrylate obtained by reacting an ether-based urethane resin obtained by reacting polyether polyol and polyisocyanate with hydroxyalkyl (meth)acrylate; Alternatively, epoxy acrylate obtained by addition reaction of epoxy resin and (meth)acrylic acid may be included, but is not limited thereto.

The index matching layer 130 is formed on top of the hard coating layer 120.

The index matching layer 130 may be introduced to optimize transmittance. The material (i.e., refractive index) and thickness of the index matching layer 130 may be selected to achieve optimal transmittance under given conditions. For example, when the medium forming each layer has a high refractive index, the index matching layer 130 may be selected to have a relatively low refractive index. This is because if the medium forming each layer is selected to have a relatively high refractive index, the reflectance may increase and consequently the transmittance may decrease. Accordingly, at least one of the material and thickness of the index matching layer 130 may be selected to adjust the overall transmittance as shown in the example above.

In an embodiment of the present invention, the index matching layer 130 may include a binary or higher compound with a refractive index of 2.0 or higher to facilitate control of transmittance. For example, the index matching layer 130 may include any one of Nb2Ox, SiNx, SiOx, ZnO, AZO, TiOx, AiNx, WOx, ZTS, and ZIST. Here, x may mean any integer or real number. Here, the visible light region may mean light within a wavelength range of 380 nm to 780 nm.

The thickness of the index matching layer 130 may be selected between 10 nm and 35 nm.

Since the index matching layer 130 is a layer connecting the hard coating layer 120 and the conductive capping layer 140, it is desirable to select a material that has good adhesion to both sides.

For example, the index matching layer 130 may include a Si-based ceramic material. In this case, it is desirable to use a ceramic-based hard coating as the hard coating layer 120.

Conductive capping layers 140 and 160 are formed on the top and bottom of the metal layer 150, respectively.

The conductive capping layers 140 and 160 may be made of three-component or higher compounds and may preferably have a large refractive index, but a smaller one than that of the index matching layer 130.

The conductive capping layers 140 and 160 may include any one selected from ITO, IZO, ZIST, and IZTO.

The conductive capping layers 140 and 160 may be formed to have a thickness of 5 nm to 40 nm. If the conductive capping layers (140, 160) are less than 5 nm, it is difficult to form the layer itself, making it difficult to perform the capping function, and if it is more than 40 nm, it affects the optical characteristics, lowering the transmittance and causing the color difference to deviate from the center. there is a problem.

The conductive capping layers 140 and 160 selected from the above materials and thicknesses effectively prevent oxidation of the metal layer 150 and are conductive, thereby contributing to forming a low-resistance electrode.

In one embodiment of the present invention, the conductive capping layers 140 and 160 may include IZO. The IZO of the conductive capping layers 140 and 160 is preferably configured so that the ratio of In2Ox:ZnO is 7:3 to 8:2. When the IZO of the conductive capping layers 140 and 160 is configured in this way, the capping function can be improved while the conductivity is minimized.

The metal layer 150 is formed by being disposed between the two conductive capping layers 140 and 160.

In an embodiment of the present invention, the metal layer 150 may include an alloy containing silver (Ag) as a main component and adding at least one of niobium (Nb) and gold (Au).

Preferably, the metal layer 150 may include 89.5 at% to 96.5 at% of silver (Ag), 0.5 at% to 1.5 at% of niobium (Nb), and 3.0 at% to 9.0 at% of gold (Au). However, inevitable components may include metals such as Pd, Cu, Fe, Ni, Pb, Sn, Zn, Mg, Cd, C, and Ta, and the concentration may be less than 100 mass ppm.

The concentration of oxygen inevitably included in the metal layer 150 may be 1000 mass ppm or less.

In an embodiment of the present invention, the overall resistance of the electrode can be reduced by forming a metal layer 150 containing silver (Ag) as a main component.

The conductive functional layer 170 is formed by being disposed on the conductive capping layer 160 formed on the metal layer 150.

The conductive functional layer 170 may be made of a material with excellent conductivity and durability (solvent resistance, etc.).

The conductive functional layer 170 may use a three-component or higher compound. For example, the conductive functional layer 170 may include any one of ITO, IZO, ZIST, and IZTO. For example, the conductive functional layer 170 may include a conductive polymer such as PEDOT.

The conductive functional layer 170 may be formed to have a thickness of 5 nm to 40 nm. If the conductive functional layer 170 is less than 5 nm, it is difficult to form the layer itself, making it difficult to perform the capping function. If it is more than 40 nm, it affects the optical characteristics, causing problems such as lower transmittance and off-center color difference. there is.

In one embodiment of the present invention, the conductive functional layer 170 may include ITO.

Figure 2 shows a method of manufacturing a low-resistance-high-current electrode 100 according to an embodiment of the present invention.

Referring to Figure 2, the substrate 110 is prepared in step S210.

The substrate 110 may include an inorganic material or an organic material, and any one of the above-described example substrates 110 may be selected. The substrate 110 in one embodiment of the present invention includes polyethylene terephthalate (PET).

In step S220, a hard coating layer 120 is formed on the substrate 110.

The hard coating layer 120 can be formed using the hard coating layer 120 material of the examples described above. The hard coating layer 120 can be formed using a spin coating method, a roll coating method, a spray coating method, a flow coating method, an inkjet printing method, a nozzle printing method, or a dip coating method using any of the compositions of the above-mentioned examples. , wet methods such as electrophoretic deposition, tape casting, screen printing, pad printing, doctor blade coating, gravure printing, gravure offset printing, and Langmuir-Blogett method. It can be formed by a coating method.

In step S230, an index matching layer 130 is formed on the hard coating layer 120.

The index matching layer 130 may be selected from any one of the index matching layers 130 of the examples described above.

The index matching layer 130 prepares a solution related to a material that can achieve the desired refractive index by spin coating, roll coating, spray coating, flow coating, inkjet printing, or nozzle printing. method, dip coating method, electrophoretic deposition method, tape casting method, screen printing method, pad printing method, doctor blade coating method, gravure printing method, gravure offset printing method, and Langmuir-Blodget method. It can be formed on the hard coating layer 120 by any one method selected from the Blogett method.

In step S240, a conductive capping layer 140 is formed on the index matching layer 130.

The conductive capping layer 140 may include any one selected from ITO, IZO, ZIST, and IZTO.

The conductive capping layer 140 may be formed to have a thickness of 5 nm to 40 nm.

In step S250, a metal layer 150 is formed on the conductive capping layer 140.

The metal layer 150 may be determined as a sputtering target so that silver (Ag), niobium (Nb), and gold (Au) can be included in a desired ratio.

Preferably, the metal layer 150 may include 89.5 at% to 96.5 at% of silver (Ag), 0.5 at% to 1.5 at% of niobium (Nb), and 3.0 at% to 9.0 at% of gold (Au). However, inevitable components of the sputtering target may include metals such as Pd, Cu, Fe, Ni, Pb, Sn, Zn, Mg, Cd, C, and Ta, and the concentration may be 100 mass ppm or less.

The concentration of oxygen inevitably included in the metal layer 150 may be 1000 mass ppm or less.

In step S260, a conductive capping layer 160 is formed on the metal layer 150.

The conductive capping layer 160 above the metal layer 150 may be formed of the same material and thickness as the conductive capping layer 140 below the metal layer 150, but is not necessarily required to be formed of the same material and thickness. The conductive capping layer 160 is selected from the materials and thickness ranges in the above-described example, but may be formed of a material and thickness different from the conductive capping layer 140 formed below.

In step S270, a conductive functional layer 170 is formed on the conductive capping layer 140 formed on the metal layer 150.

The conductive functional layer 170 may include any one selected from ITO, IZO, ZIST, and IZTO. The conductive functional layer 170 may include a conductive polymer such as PEDOT.

The conductive functional layer 170 may be formed to have a thickness of 5 nm to 40 nm.

Figure 3 is a cyclic voltammogram obtained by conducting an anode experiment using the low-resistance-high-current electrode 100 according to an embodiment of the present invention.

In the experiment, for comparison, an electrode incorporating ITO as the metal layer 150 was compared with an electrode according to the structure of an embodiment of the present invention. Blue is the result of +1V cycling, red is the result of +1.5V cycling. The conditions of comparative examples and examples are as follows.

[Comparative example]

Substrate: PET, 125nm

Hard coating layer: Acrylate-based material, 3μm

Index matching layer: SiOx, 20nm

Metal layer: ITO, 25nm

[Example]

Substrate: PET, 125nm

Hard coating layer: Acrylate-based material, 3μm

Index matching layer: SiNx, 30nm

Conductive capping layer: IZO, 10nm

Metal layer: Silver (Ag) alloy, 10 nm

Conductive functional layer: ITO, 20nm

As a result of the experiment, the electrode according to the embodiment of the present invention showed a higher amount of charge than the ITO electrode, and almost no damage was observed even when cycling at +1.5V.

Figure 4 is a sample photograph after applying +1.5V cycling to an electrode according to an embodiment of the present invention.

Referring to FIG. 4, the low-resistance-high-current electrode 100 according to an embodiment of the present invention was evaluated as having excellent durability as no special damage was found throughout the electrode even when +1.5V cycling was applied.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

100: Low-resistance-high-current electrode
110: Description
120: Hard coating layer
130: Index matching layer
140: Conductive capping layer
150: metal layer
160: Conductive capping layer
170: Conductive functional layer

Claims (5)

A substrate comprising PET and formed to a thickness of 125 nm;
A hard coating layer disposed on the substrate, containing an acrylate-based material, and formed to a thickness of 3 μm;
An index matching layer disposed on the hard coating layer, including SiNx, and formed to a thickness of 30 nm;
A metal layer disposed on the index matching layer and containing an alloy containing silver (Ag) as a main component and formed to a thickness of 10 nm;
A conductive capping layer disposed on the top and bottom of the metal layer, respectively, includes IZO, and is formed to a thickness of 10 nm; and
A conductive functional layer disposed on top of the conductive capping layer disposed on the metal layer and containing ITO and formed to a thickness of 20 nm,
The alloy includes 89.5 at% to 96.5 at% of silver (Ag), 0.5 at% to 1.5 at% of niobium (Nb), and 3.0 at% to 9.0 at% of gold (Au),
The IZO is a low-resistance-high-current electrode, characterized in that the In2Ox:ZnO ratio is 7:3 to 8:2.
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