KR101724336B1 - Transparent electrode and manufacturing method thereof - Google Patents

Abstract

There is provided a method of manufacturing a transparent electrode and a transparent electrode having excellent electrical conductivity and high charge injection efficiency. The transparent electrode according to the present invention includes a support substrate, a charge transfer electrode layer positioned on the support substrate, and a charge injection electrode layer located on the charge transfer electrode layer, wherein the charge transfer electrode layer and the charge injection electrode layer are at least partially embedded in the support substrate have.

Description

Transparent electrode and manufacturing method < RTI ID = 0.0 >

The present invention relates to a transparent electrode and a method of manufacturing a transparent electrode, and more particularly to a transparent electrode and a transparent electrode manufacturing method which are excellent in electric conductivity and high in charge injection efficiency.

Indium tin oxide (ITO) has generally been used as the transparent electrode. However, indium tin oxide has been pointed out as a factor that hinders the price competitiveness of the final product because it is a typical rare material. Therefore, it is of great interest to use ITO or replace it with other materials.

As an attempt to replace the ITO electrode, the nanowire technology based on silver (Ag) has been widely used in the fields of solar cells such as touch panels and OPVs, wiring electrodes of various electronic circuits and OLED manufacturing fields . In the case of metal nanowires, due to the unique high conductivity and the shape of a large aspect ratio, they are attracting particular attention because they can be compatible with high transparency and high conductivity when used as a transparent electrode. In addition, it has been evaluated that it is highly likely to be utilized in the development of next-generation flexible displays or electronic parts due to its excellent flexibility.

The inherent high permeability and high conductivity of metal nanowires are due to the high aspect ratio of the nanowires. 1 is a view showing an electrode using a conventional nanowire. Since the metal nanowires can form a percolated network with only a small distribution density, high electrical conductivity can be exhibited even in the presence of a vacant area as shown in FIG. 1, Electrode formation is possible. Transparent electrodes made using such metal nanowires exhibit a high figure of merit because they exhibit a transmittance of about 90% and a conductivity of less than 50 ohm / sq.

However, the characteristics of such a metal nanowire-based electrode are well suited for the manufacture of devices that utilize capacitance as a sensing parameter, such as a touch panel or a tactile sensor. However, devices that are driven by current flow, for example, organic light emitting diodes (OLED), and organic photovoltaic cells (OPV). This is because the metal nanowires have a small distribution density and a small charge injection area.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing a transparent electrode and a transparent electrode having excellent electrical conductivity and high charge injection efficiency.

According to an aspect of the present invention, there is provided an electrode including a support substrate, a charge transfer electrode layer positioned on a support substrate, and a charge injection electrode layer located on the charge transfer electrode layer, the charge transfer electrode layer, The charge injection electrode layer is at least partially embedded in the support substrate.

The charge transporting electrode layer may include metal nanowires, and the charge injecting electrode layer may include a conductive polymer.

The supporting substrate may be formed of a material such as polyimide (PI), polyamide (PA), polyamide-imide, polyurethane (PU), polyurethane acrylate (PUA) (PA), polyethyleneterephthalate (PET), polyether sulfone (PES), polyethylene naphthalate (PEN), polycarbonate (PC), polymethyl methacrylate polymethylmethacrylate (PMMA), polyether imide (PEI), polydimethylsiloxane (PDMS), acrylic resin, silicone resin, fluororesin, modified epoxy resin and combinations thereof.

The charge transporting electrode layer is entirely embedded in the supporting substrate, and the charge injection electrode layer can be embedded in the supporting substrate except for the upper surface.

The charge transporting electrode layer or the charge injection electrode layer may be formed on the substrate in two or more layers.

According to another aspect of the present invention, there is provided a light emitting device comprising: a support substrate; a charge injection electrode layer located on the support substrate; And a charge transfer electrode layer positioned on the charge injection electrode layer, wherein the charge injection electrode layer and the charge transport electrode layer are provided with a transparent electrode at least partially embedded in the support substrate.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: forming a charge injection electrode layer on a manufacturing board; Forming a charge transporting electrode layer on the charge injection electrode layer; Forming a support substrate on the charge transporting electrode layer, the charge injection electrode layer and the charge transporting electrode layer being embedded in the support substrate; And a step of removing the manufacturing substrate.

The step of forming the support substrate may be performed so that the support substrate is formed so as to be embedded in the whole of the charge injection electrode layer and in the charge transport electrode layer except for the upper surface.

The transparent electrode manufacturing method may further include the step of patterning the charge injection electrode layer and the charge transport electrode layer after the step of forming the charge transporting electrode layer. The supporting substrate may be formed by filling the patterned region of the charge injection electrode layer and the charge transport electrode layer .

As described above, according to the embodiments of the present invention, the transparent electrode is formed as a charge transfer electrode layer and a charge injection electrode layer, embedded therein, and the charge injection electrode layer is formed in a state exposed to the outside, There is an advantage that it is usefully used for a charge injection electrode layer and an element requiring charge injection, for example, an OLED or an OPV cell.

In addition, a transparent electrode can be manufactured by embedding a charge transfer electrode layer and a charge injection electrode layer using a polymer resin on a supporting substrate, and thus a flexible transparent electrode can be mass-produced by a roll-to-roll method.

1 is a view showing an electrode using a conventional nanowire.
FIGS. 2 to 7 are views for explaining a method of manufacturing a transparent electrode according to an embodiment of the present invention.
FIG. 8 is a photograph of the surface of the conductive polymer layer, FIG. 9 is a photograph of the surface of the nanowire layer formed on the conductive polymer layer, and FIG. 10 is a photograph of the exposed upper surface of the conductive polymer layer embedded in the supporting substrate.
FIG. 11 is a view of an electrode according to an embodiment of the present invention, and FIG. 12 is a cross-sectional photograph of a conductive polymer layer and a nanowire layer of the electrode of FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. The embodiments of the present invention are provided to enable those skilled in the art to more fully understand the present invention. It should be understood that while the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, The present invention is not limited thereto.

FIGS. 2 to 7 are views for explaining a method of manufacturing a transparent electrode according to an embodiment of the present invention. Hereinafter, a method of manufacturing a transparent electrode and a transparent electrode according to the present invention will be described with reference to FIGS. 2 to 7. FIG.

A transparent electrode according to an embodiment of the present invention is an electrode including a support substrate, a charge transfer electrode layer positioned on a support substrate, and a charge injection electrode layer positioned on a charge transfer electrode layer, wherein the charge transfer electrode layer and the charge injection electrode layer are formed on a support substrate At least a portion thereof is embedded.

The transparent electrode includes two or more electrode layers. The transparent electrode may include a charge transfer electrode layer having high charge transfer efficiency and a charge injection electrode layer for injecting charge. Accordingly, the transparent electrode can be effectively used depending on the device or device to be used. When the transparent electrode is used as an electrode for sensing a change in capacitance such as a touch panel or a tactile sensor, it can be used including an electrode layer that is effective in charge transport, such as a charge transporting electrode layer, and the transparent electrode can be used for a charge injection area For example, when the amount of emitted light is increased or decreased, an electrode layer that is effective for charge injection, such as a charge injection electrode layer, may be used.

That is, the charge transport electrode layer is preferably an electrode layer in which charges injected by an external power source or the like are actively transported, and is realized as a material having high electrical conductivity. For example, the charge transporting electrode layer preferably includes a metal. The metal is suitable for the charge transporting electrode layer because of its high electrical conductivity, but it is opaque to form the transparent electrode according to the present invention, so that it is used as a metal thin film layer rather than the metal layer itself, or more preferably, when metal nanowires are used, And transparency can be ensured.

The metal nanowires that can be used for the charge transporting electrode layer may be metal nanowires in the form of nano wire. For example, the metal nanowires may be silver (Ag), gold (Au), copper (Cu), nickel (Ni), platinum (Pt), palladium (Pd), or aluminum (Al) And a core-shell wire made of a combination of the two.

The charge injection electrode layer means an electrode layer having high efficiency of injecting charges injected by an external power supply or the like into an external element or the like. In the case of the charge transporting electrode layer, for example, metal nanowires having high electrical conductivity can be used to increase the charge transport efficiency. However, since the distribution density is low due to the high transparency of metal nanowires, It is not suitable as an electrode layer. That is, the charge injecting electrode layer needs to be improved in charge injection efficiency including a material capable of charge injection uniformly and widely considering the total area in addition to the electric conductivity.

For example, in the case of a conductive polymer, the electrical conductivity is lower than that of the metal nanowire by 10 times to 100 times. When the conductive polymer is mixed with the binder solution to form a layer, the conductive polymer is uniformly distributed over the formed layer Can be. Accordingly, if the conductive polymer is uniformly distributed over the entire contact surface with the device requiring charge injection, the charge injection can be performed over the entire contact surface, so that the charge injection electrode layer having high charge injection efficiency can be realized.

A conductive polymer such as poly (3,4-ethylenedioxythiophene), PEDOT (poly (3,4-ethylenedioxythiophene)) can be used as the conductive polymer which can be used for the charge injection electrode layer. PEDOT: PSS (polystyrene sulfonate) And may be generally applied in the form of a mixture with a binder resin to form a charge injection electrode layer.

In addition, as the conductive material such as graphene, carbon nanotube, or conductive paste, materials effective for charge injection may be used for the charge injection electrode layer.

In the case where the charge transfer electrode layer is a kind of linear conductor and the charge injection electrode layer is a planar conductor, the charges move in the charge transfer electrode layer and charge can move across the entire surface in the charge injection electrode layer, Charge injection becomes possible.

The charge transporting electrode layer and the charge injection electrode layer are formed in a shape in which at least part of the charge transporting electrode layer and the charge injection electrode layer are embedded in the supporting substrate. "Embedded form" will be described below with reference to the drawings.

The supporting substrate is an element constituting the transparent electrode in a state where the charge transfer electrode layer and the charge injection electrode layer are embedded. The supporting substrate is made of a material selected from the group consisting of polyimide (PI), polyamide (PA), polyamide-imide (PU), polyurethane (PU), polyacrylamide (PA), polyethyleneterephthalate (PET), polyether sulfone (PES) Polymers such as polyethylene naphthalate (PEN), polycarbonate (PC), polymethylmethacrylate (PMMA), polyetherimide (PEI), polydimethylsiloxane (PDMS) Acrylic resins, silicone resins, fluororesins, modified epoxy resins, and combinations thereof. In the case of these resins, the charge transporting electrode layer and the charge injection electrode layer may be embedded before being subjected to a curing step while being used as a support substrate. That is, when the patterning is performed on the charge transporting electrode layer and the charge injection electrode layer, and when the metal nanowire is used in the charge transporting electrode layer, the patterned region and the vacant region of the metal nanowire are filled with the above- And then the transparent electrode can be formed by curing it. Curing can be thermal or UV curing depending on the type of resin.

A method of manufacturing such a transparent electrode will be described below with reference to Figs. 2 to 7. In FIG. 2, a charge injection electrode layer 120 is formed on a manufacturing substrate 110. The charge injection electrode layer 120 does not cover the entire upper surface of the manufacturing substrate 110 but is formed only in a part to be embedded in the supporting substrate 140. For the charge injection electrode layer 120, a conductive polymer mixed with a binder, for example, PEDOT: PSS in the form of an aqueous solution, may be used.

A charge transfer electrode layer 130 is formed on the charge injection electrode layer 120. In FIG. 3, the charge transporting electrode layer 130 is formed of metal nanowires, but the present invention is not limited thereto.

The charge injection electrode layer 120 may be patterned together with the charge transporting electrode layer 130 for an electrode pattern of a desired shape (see FIG. 4). The charge injecting electrode layer 120 and the charge transporting electrode layer 130 may be separately patterned, or may be patterned simultaneously. In order to perform patterning simultaneously, the components of the binder or the aqueous solution of the charge injection electrode layer 120 can be adjusted so that simultaneous patterning is possible. Or the charge injecting electrode layer and the charge transporting electrode layer may be formed through a printing process at the time of formation, so that a separate patterning process may not be required.

The supporting substrate 140 is formed to cover the top and side surfaces of the patterned charge injection electrode layer 120 and the charge transport electrode layer 130 (see FIG. 5). The supporting substrate 140 may be formed of a polymer resin so that the uncured liquid or semi-solid polymeric resin is transferred to the charge injection electrode layer 120 and the charge transfer electrode layer 130 in the form of a supporting substrate 140 Can be covered. In this case, the polymer resin to be the supporting substrate 140 fills the patterning region, and if the charge transporting electrode layer 130 is a nanowire, the empty region of the nanowire is filled. When the polymer resin fills the patterning region and the vacant region, the support substrate 140 can be formed by curing the polymer resin. When the manufacturing substrate 110 is removed, the transparent electrode 100 having the charge injection electrode layer 120 and the charge transfer electrode layer 130 as shown in FIG. 6 embedded in the support substrate 140 is obtained.

7 is a cross-sectional view taken along the line AA 'of FIG. 6. As described above, the supporting substrate 140 fills the inside of the charge transfer electrode layer 130, and the charge transfer electrode layer 130 and the charge injection And filling the patterned region of the electrode layer 120. In addition, the upper surface of the charge injection electrode layer 120 is exposed (the upper and lower surfaces are used in a relative sense, meaning at least one surface to be a contact surface with the charge injection electrode of the charge injection electrode layer is exposed to the outside) And is embedded in the support substrate 140.

FIG. 8 is a photograph of the surface of the conductive polymer layer, FIG. 9 is a photograph of the surface of the nanowire layer formed on the conductive polymer layer, and FIG. 10 is a photograph of the exposed upper surface of the conductive polymer layer embedded in the supporting substrate. According to the present invention, a transparent electrode is used as a charge injection electrode layer, PEDOT: PSS is used as a charge transfer electrode layer, silver nano wire is used as a charge transporting electrode layer, I got a picture. As a manufacturing substrate, a glass substrate was used to lower the surface roughness of the charge injecting electrode layer.

8 shows the surface of the PEDOT: PSS layer, FIG. 9 shows the silver nanowire layer formed on the PEDOT: PSS layer, and FIG. 10 shows the surface of the PEDOT: PSS layer on the surface separated from the glass substrate after application of the polyimide substrate . It can be seen that the surface of the PEDOT: PSS layer of FIG. 10 is lower than the surface roughness of the PEDOT: PSS layer of FIG. 8 by transferring the surface roughness of the glass substrate. Therefore, since the manufacturing substrate can be suitably used to adjust the surface roughness of the transparent electrode of the present invention properly, and the manufactured substrate is removed from the manufactured transparent electrode, the manufacturing substrate does not necessarily have to be thin or flexible, Can be used if it can be improved or easily separated. For example, the manufacturing substrate may be a glass substrate, a silicon substrate, a PET substrate, or a PES substrate.

FIG. 11 is a view illustrating a transparent electrode according to an embodiment of the present invention, and FIG. 12 is a cross-sectional photograph of a conductive polymer layer and a nanowire layer of the transparent electrode of FIG. 11, the PEDOT: PSS layer 220 embedded in the polyimide supporting substrate 240 is shown as an electrode pattern, and the silver nanowire layer is entirely embedded in the polyimide supporting substrate 240 and is not shown in the drawing. In FIG. 12, it can be seen that the silver wire layer 230 is formed on the end face of the PEDOT: PSS layer 220 in FIG.

Although the charge injection electrode layer is disposed on the upper surface and the charge transfer electrode layer is entirely embedded in the support substrate in the above embodiment of the present invention, the charge transfer electrode layer is exposed to the outside from the support substrate, A transparent electrode in which the entirety is embedded in the supporting substrate can also be manufactured by a method similar to that of the transparent electrode manufacturing method of the present invention. If the charge transport electrode layer is exposed to the outside and used for devices requiring rapid electrical connection, the charge injection electrode layer is drawn into the support substrate and the charge transport electrode layer is exposed to the outside and functions.

In the embodiment of the present invention, the charge injection electrode layer and the charge transfer electrode layer are two-layered, but the charge injection electrode layer has two layers, the charge transfer electrode layer has one layer or the charge transfer electrode layer has two layers, It may be realized as three or more layers depending on the purpose of implementing a desired function as in the case of a single electrode layer.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the invention as defined by the appended claims. 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.

100 transparent electrode
110 manufactured substrate
120 charge injection electrode layer
130 charge transfer electrode layer
140 supporting substrate
150 base layer
220 PEDOT: PSS layer
230 silver wire layer
240 polyimide support substrate

Claims (10)

The support substrate,
A charge transporting electrode layer located on the supporting substrate; And
And a charge injection electrode layer located on the charge transporting electrode layer,
Wherein the charge transporting electrode layer and the charge injection electrode layer are at least partially embedded in the supporting substrate,
Wherein the charge transporting electrode layer is an electrode layer embedded entirely in the supporting substrate and carrying a charge including metal nanowires,
Wherein the charge injection electrode layer is an electrode layer embedded in the support substrate except for the upper surface and including a conductive polymer and injecting a charge.
delete delete The method according to claim 1,
Wherein the support substrate comprises:
Polyimide (PI), polyamide (PA), polyamide-imide, polyurethane (PU), polyurethane acrylate (PUA), polyacrylamide , PA), polyethylene terephthalate (PET), polyether sulfone (PES), polyethylene naphthalate (PEN), polycarbonate (PC), polymethylmethacrylate Transparent electrode comprising any one selected from the group consisting of polyetherimide (PEI), polydimethylsiloxane (PDMS), acrylic resin, silicone resin, fluorine resin, modified epoxy resin and combinations thereof.
delete The method according to claim 1,
Wherein at least one of the charge transporting electrode layer and the charge injection electrode layer is two or more.
delete Forming a charge injection electrode layer on the manufacturing substrate; Forming a charge transporting electrode layer on the charge injection electrode layer; Forming a support substrate on the charge transport electrode layer, the charge injection electrode layer and the charge transport electrode layer being embedded in the support substrate; And removing the manufacturing substrate,
The step of forming the supporting substrate is performed so that the supporting substrate is embedded so as to be embedded in the whole of the charge transporting electrode layer and the top surface of the charge injection electrode layer,
Wherein the charge transporting electrode layer is an electrode layer embedded entirely in the supporting substrate and carrying a charge including metal nanowires,
Wherein the charge injection electrode layer is an electrode layer embedded in the support substrate except for the top surface and including a conductive polymer and injecting a charge.
delete The method of claim 8,
After the step of forming the charge transporting electrode layer,
Further comprising patterning the charge injection electrode layer and the charge transport electrode layer,
Wherein the supporting substrate is formed while filling the patterning regions of the charge injection electrode layer and the charge transporting electrode layer.

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