KR20120042698A - Method for forming electrode - Google Patents

Abstract

PURPOSE: An electrode formation method is provided to obtain high packing density by completely eliminating small ethylenediamine molecules through a sintered process. CONSTITUTION: A polymer layer is formed on the top of the substrate. An amino-silane pattern is formed on the polymer layer. The substrate having amino-silane pattern is dipped in gold nano particle aqueous solution. A gold nano particle layer is formed in the amino-silane pattern. The substrate having the gold nano particle layer is dipped in ethylene diamine aqueous solution. An ethylene diamine layer is formed on the gold nano particle layer. The substrate having the gold nano particle layer and the ethylene diamine layer is sintered. A step for forming the gold nano particle layer and the ethylene diamine layer is reciprocally and repeatedly executed.

Description

Electrode Formation Method {Method for forming Electrode}

The present invention relates to a method of forming an electrode, and more particularly, to a method of forming an electrode on a flexible substrate.

Recently, interest in flexible electronic devices such as flexible solar cells, flat panel displays, and sensors has been amplified. However, in such flexible electronic devices, it is very difficult to form low resistance metal electrodes without damaging the polymer substrate. This is because the polymer substrate is not chemically suitable for the harsh environment of general photolithography.

Thus, numerous approaches have been attempted to form metal electrodes on polymer substrates, such as transfer printing, electroless deposition, capillary micromolding or decal transfer lithography. It became.

However, these methods are too complicated and too expensive to be used in flexible electronics.

Recently, microcontact printing (MCP), nanoimprinting, ink-jet printing and the like have been used to prepare metal electrodes using gold nanoparticles (GNP). Proposed. In particular, MCP is drawing attention because of the advantages of a simple, low cost and fast process. The disadvantage is the rough surface and low adhesion.

Meanwhile, studies have been made to manufacture a GNP multilayer using LBL deposition (layer-by-layer deposition). However, GNP multilayers produced by LBL deposition have a problem of low electrical conductivity due to the low packing density of residual linkers, capping molecules and GNP layers.

The problem to be solved by the present invention is to prepare a method for producing an electrode that can exhibit a low resistance without damaging the polymer layer.

Technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above technical problem, an aspect of the present invention provides a step of forming a polymer layer on a substrate, forming an aminosilane pattern on the polymer layer, and immersing the substrate on which the aminosilane pattern is formed in an aqueous gold nanoparticle solution. Shaking to form a gold nanoparticle layer on the aminosilane pattern, immersing the substrate on which the gold nanoparticle layer is formed in an aqueous solution of ethylene diamine and shaking to form an ethylene diamine layer on the gold nanoparticle layer and the gold And sintering the substrate on which the nanoparticle layer and the ethylene diamine layer are formed, and repeatedly forming the gold nanoparticle layer and the ethylene diamine layer by alternately repeating the multiplication of the gold nanoparticle layer and the ethylene diamine layer. It provides a method for forming an electrode, characterized in that to form a layer do.

The substrate may be a silicon substrate or a glass substrate.

The polymer layer may include polyimide.

Forming the aminosilane pattern is characterized by using microcontact printing, nanoimprinting or ink-jet printing.

The forming of the aminosilane pattern may include introducing a hydroxyl group on the surface of the polymer layer and contacting a patterned PDMS stamp coated with aminosilane on the polymer layer introducing the hydroxyl group to contact the aminosilane. Forming a pattern may be included.

The aminosilane may be 3-aminopropyltriethoxysilane.

The gold nanoparticle aqueous solution may be an aqueous gold nanoparticle solution surrounded by citrate.

As described above, according to the present invention, it is possible to provide an electrode capable of exhibiting low resistance without damaging the polymer layer.

However, the effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a schematic view showing an electrode manufacturing method according to an embodiment of the present invention.
2 and 3 are graphs showing the surface coverage of the GNP multilayer against the shaking speed.
4 and 5 are graphs showing UV-vis absorbance for the GNP multilayer of the two layers.
Figure 6 is a cross-sectional FE-SEM images of the GNP multilayer prepared according to the GNP multilayer manufacturing example.
7 shows surface FE-SEM images of a GNP multilayer prepared according to the GNP multilayer preparation example.
8 are images showing characteristics of a gold electrode pattern manufactured according to a gold electrode pattern manufacturing example.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Like numbers refer to like elements throughout. In addition, in the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

In addition, in the figures, where a layer is said to be "on" another layer or substrate, it may be formed directly on the other layer or substrate, or a third layer may be interposed therebetween.

Example

1 is a schematic view showing an electrode manufacturing method according to an embodiment of the present invention.

Referring to Figure 1, a substrate, for example a silicon substrate, is provided. As another example, various substrates such as glass substrates can be used.

A polyimide (PI) layer is formed on the silicon substrate. However, the polyimide layer is not limited thereto, and any polymer layer may be used.

In addition, a polymer substrate, for example, a polyimide substrate can be used.

An aminosilane pattern is formed on the polyimide layer. Forming the aminosilane pattern may use microcontact printing, nanoimprinting or ink-jet printing.

For example, hydroxyl (OH) groups are introduced onto the surface of the polyimide layer by exposing the polyimide (PI) layer to H ₂ O plasma and etching the H ₂ O plasma.

Meanwhile, a PDMS substrate having a surface patterned is prepared, and aminosilane is coated on the PDMS substrate. The aminosilane may be 3-aminopropyltriethoxysilane (γ-APS).

The aminosilane-coated PDMS substrate is contacted on the polyimide layer into which the hydroxyl group is introduced to form an aminosilane pattern on the polyimide layer.

The aminosilane and the polyimide layer may be bonded by a siloxane bond (Si-O), and as a result, the aminosilane pattern may be formed as a self-assembled monolayer on the polyimide layer.

The substrate on which the aminosilane pattern is formed is immersed in an aqueous gold nanoparticle solution and shaken to form a gold nanoparticle layer on the aminosilane pattern.

For example, an aqueous solution (GNP aqueous solution) in which gold nanoparticles (GNP) is dispersed is provided on a substrate on which the aminosilane pattern is formed, and a substrate provided with an aqueous GNP aqueous solution is shaken. Specifically, the substrate in which the aminosilane pattern is formed is placed in a container containing a GNP aqueous solution, and the container is shaken. In the aqueous GNP solution, GNP may be surrounded by an anion, for example, citrate (Ctrate, C ₃ H ₅ O (COO) ₃ ^3- ). In addition, the amino group of the aminosilane may have a positive charge due to contact with the aqueous solution. In the shaking process, GNP surrounded by anions is selectively adsorbed on the positively charged aminosilane pattern to form a GNP layer on the aminosilane pattern.

Subsequently, the substrate on which the gold nanoparticle layer is formed is immersed in an ethylene diamine aqueous solution and shaken to form an ethylene diamine layer on the gold nanoparticle layer.

For example, an aqueous solution of ethylene diamine (ethylenediamine, EDA) is provided on the substrate on which the GNP layer is formed, and the substrate on which the EDA aqueous solution is provided is shaken. Specifically, the substrate in which the GNP layer is formed is placed in a container containing an EDA aqueous solution, and the container is shaken. EDA in the aqueous EDA solution may have a positive charge. Thus, in the shaking process, the positively charged EDA is selectively adsorbed onto the GNP layer surrounded by anions. As a result, an EDA layer is formed on the GNP layer.

The forming of the GNP layer and the forming of the EDA layer may be alternately repeated to form multilayers of the GNP layer and the EDA layer.

By forming the GNP layer using the shaking-assisted LBL lamination method as described above, a gold layer having a large packing density, that is, having a good surface coverage can be formed within a short time.

The substrate on which the alternating laminate of the GNP layer and the EDA layer is formed is sintered. In this process, the aminosilane pattern, the EDA layer, and the citrate surrounding gold, which are organic layers, may be removed, and a gold pattern may be formed on the polyimide layer.

Hereinafter, preferred examples are provided to aid the understanding of the present invention. However, the following experimental examples are only for helping understanding of the present invention, and the present invention is not limited to the following experimental examples.

Experimental Examples; examples>

<GNP multilayer manufacturing example>

The polyimide (PMDA-ODA) layer was formed on a silicon substrate using spin coating. The polyimide layer was H ₂ O plasma etched to introduce hydroxyl groups onto the polyimide layer. Thereafter, γ-APS (Gelest) monolayer was formed on the polyimide layer using a PDMS stamp. This resultant and the GNP (12.8 nm) aqueous solution surrounded by citrate is placed in an orbital shaker and shaken for 1 to 15 minutes at a shaking speed of 90 to 150 rpm to form a GNP layer on the γ-APS monolayer. It was. The resultant and EDA (Aldirch) solution (10-30 mM) were placed in an orbital shaker and shaken for 3-7 minutes at a shaking speed of 90-150 rpm to form an EDA layer on the GNP layer. The formation of the GNP layer and the EDA layer was repeated.

2 and 3 are graphs showing the surface coverage of the GNP multilayer against the shaking speed.

Referring to FIG. 2, the surface coverage of the GNP layer according to the shaking-assisted LBL stacking method is 58%, which is improved compared to the surface coverage of 30% according to the general LBL stacking method.

This is because the kinetic energy provided by the shaking method could overcome the ionic repulsion of the gold nanoparticles and forcibly deposit more gold nanoparticles in the spaces between the gold nanoparticles.

The shaking speed is preferably 90 rpm to 150 rpm. If the shaking speed is less than 90 rpm, the kinetic energy provided by the shaking method may be too low to overcome ionic repulsion. In addition, when the shaking speed is more than 150rpm, the kinetic energy provided by the shaking method is too high to maintain the gravitational force (gravityal force) may be low surface coverage.

Referring to FIG. 3, it takes 60 minutes to form the GNP layer according to the general LBL lamination method, whereas the formation time of the GNP layer according to the shaking-assisted LBL lamination method is very short 10 minute lamination time (shaking time). It can be seen that

4 and 5 are graphs showing UV-vis absorbance for the GNP multilayer of the two layers. 4 illustrates the GNP multilayer manufacturing example, using a glass substrate instead of the silicon substrate used, forming a GNP layer under a shaking time of 10 minutes, and forming an EDA layer under a shaking time of 5 minutes. After forming samples of the GNP layer at 10 minutes of shaking time again, the samples were prepared by splitting the concentration of EDA solution into 0, 10mM, 20mM and 30mM, and then UV-vis absorbance of these samples. On the other hand, Figure 5 performs the manufacturing example of the GNP multilayer, using a glass substrate instead of the silicon substrate used, the GNP layer is formed under a shaking time of 10 minutes, an EDA layer is formed under a concentration of 20mM After forming the GNP layer under the shaking time of 10 minutes again, the samples having the shaking time for forming the EDA layer into 0, 3 minutes, 5 minutes and 7 minutes were prepared, and then UV- vis absorbance.

Figure 6 is a cross-sectional FE-SEM images of the GNP multilayer prepared according to the GNP multilayer manufacturing example.

7 shows surface FE-SEM images of a GNP multilayer prepared according to the GNP multilayer preparation example.

The following table is a table showing the characteristics of the GNP multilayer prepared according to the GNP multilayer preparation example.

[table]

<Gold electrode pattern manufacturing example>

The polyimide (PMDA-ODA) layer was formed on a silicon substrate using spin coating. The polyimide layer was H ₂ O plasma etched to introduce hydroxyl groups onto the polyimide layer. Thereafter, γ-APS (Gelest) monolayer was formed on the polyimide layer using a PDMS stamp. The resultant and the citrate aqueous solution surrounded by citrate (2.5nm) was placed in an orbital shaker and shaken for 1 to 15 minutes at a shaking speed of 90 to 150 rpm to form a GNP layer on the γ-APS monolayer. The resultant and EDA (Aldirch) solution (10-30 mM) were placed in an orbital shaker and shaken for 3-7 minutes at a shaking speed of 90-150 rpm to form an EDA layer on the GNP layer. The formation of the GNP layer and the EDA layer was repeated, and a total of 20 GNP layers were formed. Thereafter, the resultant was sintered at 150 for 1 hour.

8 are images showing characteristics of a gold electrode pattern manufactured according to a gold electrode pattern manufacturing example.

Referring to FIG. 8, the gold electrode pattern exhibits a conductivity of 2 × 10 ⁵ Ω ⁻¹ cm ⁻¹ , which is greatly improved compared to the conductivity of the gold electrode pattern formed by a general LBL lamination method or any other method. It turns out that it is very close to 4 * 10 <^5> Pa <^-1> cm <^-1> which is the conductivity shown.

This is because small EDA molecules are completely removed through the sintering process, resulting in a high packing density.

In addition, it can be seen that the gold electrode pattern (light yellow) prepared according to the gold electrode pattern preparation example was not formed in the unwanted region.

In the above, the present invention has been described in detail with reference to preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications and changes by those skilled in the art within the spirit and scope of the present invention. This is possible.

Claims (7)

Forming a polymer layer on the substrate;
Forming an aminosilane pattern on the polymer layer;
Immersing and shaking the substrate on which the aminosilane pattern is formed in an aqueous gold nanoparticle solution to form a gold nanoparticle layer on the aminosilane pattern;
Immersing and shaking the substrate on which the gold nanoparticle layer is formed in an aqueous solution of ethylene diamine to form an ethylene diamine layer on the gold nanoparticle layer; And
Sintering the substrate on which the gold nanoparticle layer and the ethylene diamine layer are formed;
And repeatedly forming the gold nanoparticle layer and the ethylene diamine layer alternately to form a multilayer of the gold nanoparticle layer and the ethylene diamine layer. The method of claim 1,
And the substrate is a silicon substrate or a glass substrate. The method of claim 1,
The polymer layer is an electrode forming method comprising a polyimide. The method of claim 1,
Forming the aminosilane pattern is an electrode forming method, characterized in that using micro-contact printing, nanoimprinting or ink-jet printing. The method of claim 1, wherein forming the aminosilane pattern comprises:
Introducing a hydroxyl group onto the surface of the polymer layer; And
Contacting a patterned PDMS stamp coated with aminosilane on the polymer layer introducing the hydroxyl group to form an aminosilane pattern. The method of claim 1,
And wherein said aminosilane is 3-aminopropyltriethoxysilane. The method of claim 1,
The gold nano-particle aqueous solution is a gold nano-particle aqueous solution surrounded by citrate.

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