KR20100114401A - Method for fabrication of conductive film using sputtering and conductive film - Google Patents

Abstract

PURPOSE: A conductive film and a method for manufacturing the same are provided to simply form the conductive film by using a sputtering process. CONSTITUTION: A carbon nano tube is dispersed in solvents. A conductive film(100) includes a metal layer(130) deposited to cover one side of a carbon nano tube layer. A substrate(110) is made of light transmitting materials. The metal layer is made of gold, silver, copper, palladium, nickel, or platinum.

Description

TECHNICAL FOR FABRICATION OF CONDUCTIVE FILM USING SPUTTERING AND CONDUCTIVE FILM}

The present invention relates to a method for improving the electrical conductivity of a conductive film having light transmittance, a method for producing a conductive film, and a conductive film.

Conductive film is a kind of functional optical film and is widely used in home appliances, industrial equipment, and office equipment.

Today, a transparent conductive film having a light transmissive property is widely used in devices that simultaneously require two purposes of low transparency and low resistance, such as solar cells and various displays (PDP, LCD, OLED). Generally, indium tin oxide (ITO) has been used as a transparent conductive film, but it is not only expensive, but also has low strength and stiffness. Indicates.

Accordingly, a method of manufacturing a conductive film having improved electrical conductivity while maintaining light transmittance using a new material may be considered.

One object of the present invention is to provide a transparent conductive film manufacturing method and a conductive film of a different form from the prior art.

Another object of the present invention is to provide a transparent conductive film with improved electrical conductivity.

In order to achieve one object of the present invention, a conductive film manufacturing method according to an embodiment of the present invention includes a dispersion step, a forming step and a deposition step. The dispersing step disperses the carbon nanotubes in a solvent. In the forming step, the dispersion is coated on one surface of the substrate to form a carbon nanotube layer. In the deposition step, a metal film is deposited on one surface of the carbon nanotube layer through metal sputtering.

According to another aspect of the present invention, the solvent is N-methylpyrrolidone (NMP, N-methyl-2-pyrrolidone), dimethylacetamide (DMAc), dimethylformamide (DMF), cyclohexanone, ethyl alcohol, water And chlorobenzene.

According to another aspect of the invention, the method for producing a conductive film includes the step of pretreating the carbon nanotubes through at least one of cutting and acid and chemical reaction. The conductive film manufacturing method may include chemically treating the surface so that the substrate is hydrophilic or hydrophobic.

According to another aspect of the invention, the metal film is formed to a thickness of 0.1 to 100 nanometers (nm). The metal may be at least one of gold, silver, copper, palladium, nickel and platinum.

According to another aspect of the invention, the forming step is a vacuum filtration method, self-assembly method, Langmuir-Blodgett method, solution casting method, bar Carbon nanotube layer by any one of bar coating method, dip coating method, spin coating method, spray coating method and roll-to-roll method To form.

In addition, the conductive film manufacturing method according to another embodiment of the present invention includes an enhancement step, a dispersion step, a forming step and a deposition step. The enhancement step improves the solvent affinity of the carbon nanotubes through physical cleavage or oxidation. The dispersing step disperses the carbon nanotubes in a solvent. In the forming step, the dispersion is coated on the substrate to form a carbon nanotube film. In the deposition step, a metal film is deposited on one surface of the carbon nanotube film through metal sputtering.

In addition, the present invention provides a conductive film in order to realize the above object. The conductive film includes a light transmissive substrate, a carbon nanotube layer, and a metal film. The carbon nanotube layer is formed by coating a carbon nanotube dispersion on one surface of the substrate. The metal film is deposited on the carbon nanotube layer to cover one surface of the carbon nanotube layer. The carbon nanotubes may be formed of at least one of a single wall, a double wall, and a multi wall carbon nanotube. The light transmissive substrate may be formed of at least one of glass, quartz, synthetic resin, and polymer material.

The conductive film manufacturing method and conductive film according to the present invention configured as described above can form a conductive film in a simpler process through sputtering. In addition, a conductive film having improved electrical conductivity is realized while maintaining light transmittance.

Hereinafter, a method for manufacturing a conductive film and a conductive film according to the present invention will be described in more detail with reference to the accompanying drawings. In the present specification, the same or similar reference numerals are assigned to the same or similar configurations in different embodiments, and the description thereof is replaced with the first description. As used herein, the singular forms "a", "an" and "the" include plural forms unless the context clearly indicates otherwise.

1 is a cross-sectional view showing an embodiment of a conductive film 100 according to the present invention.

Referring to the figure, the conductive film 100 includes a light transmissive substrate 110, a carbon nanotube layer (CNT layer, Carbon nanotube layer, 120) and a metal film 130.

The substrate 110 may be formed of a light transmissive material, and may be formed of at least one of glass, quartz, synthetic resin, and polymer material. The substrate 110 may be formed of a thin film.

The carbon nanotube layer 120 is formed by coating a carbon nanotube dispersion on one surface of the substrate 110.

The carbon nanotubes may be formed of at least one of a single wall, a double wall, and a multi wall carbon nanotube. The multi-walled carbon nanotubes may include thin multiwall carbon nanotubes.

The metal film 130 is deposited on one surface of the carbon nanotube layer. The deposition is performed by metal sputtering, and the metal is formed to cover the carbon nanotube layer.

The metal film 130 is formed of at least one of gold, silver, copper, palladium, nickel, and platinum. The metal film 130 may be formed to a thickness of 0.1 to 100 nanometers (nm). The thickness of the metal film 130 may be implemented through sputtering and does not significantly reduce the degree of light transmittance (hereinafter referred to as 'transparency') of the conductive film 100. Through this, the conductive film 100 having improved electrical conductivity is realized while maintaining transparency.

Hereinafter, a method of manufacturing a conductive film that can implement the conductive film 100 of FIG. 1 will be described. 2 is a flow chart showing an embodiment of a conductive film manufacturing method related to the present invention.

First, the surface of the substrate is chemically treated (S10), and carbon nanotubes are pretreated (S20).

The chemical treatment step S10 chemically treats the surface such that the substrate is hydrophilic or hydrophobic. The substrate is formed of a light transmissive material, and may be formed of at least one of glass, quartz, synthetic resin, and polymer material.

The chemical treatment step S10 will be described by way of example. A plate-shaped substrate formed of a material of polyethylene (PET) is cut to a size of about 1.5 x 5 cm 2. The substrate was immersed in 2 normal sodium hydroxide solution and reacted at about 70 ° C. for about 30 minutes. The substrate is then washed and then naturally dried. This allows the substrate to have a hydrophilic surface.

In the pretreatment step (S20), the carbon nanotubes are pretreated through at least one of cutting and acid and chemical reaction.

The preprocessing step S20 will be described by way of example. 400 mg of carbon nanotubes are cut by stirring for 1 hour in a sulfuric acid and nitric acid mixed solution having a volume ratio of 3: 1. Dilution with distilled water to form a carbon nanotube suspension, the carbon nanotube suspension is filtered through an artificial fluoropolymer (PTFE, polytetrafluoroethylene) membrane and then dried in a lyophilizer. Through this, the carbon nanotubes are cut in the state where the carboxyl group is exposed.

Next, the carbon nanotubes are dispersed in a solvent (S100).

The solvent may be at least one of N-methylpyrrolidone (NMP, N-methyl-2-pyrrolidone), dimethylacetamide (DMAc), dimethylformamide (DMF), cyclohexanone, ethyl alcohol, water and chlorobenzene. Can be.

For example, the dispersing step (S100) is described. After dispersing 0.01 wt% of carbon nanotubes in a dimethylformamide (DMF) solvent, the dispersant is dispersed in a sonicator for 10 hours.

Next, the dispersion is coated on one surface of the substrate to form a carbon nanotube layer (S200).

Formation step (S200) is a vacuum filtration method, self-assembly method, Langmuir-Blodgett method, solution casting method, bar coating method A carbon nanotube layer on the substrate by any one of a dip coating method, a spin coating method, a spray coating method, and a roll-to-roll method. .

Referring to the formation step (S200), for example, after dropping about 0.1mL of the carbon nanotube dispersion on the hydrophilic substrate, the dimethylformamide solvent is evaporated through natural drying or vacuum oven.

When the carbon nanotube layer is formed through the forming step (S200), a metal film is deposited on one surface of the carbon nanotube layer through metal sputtering (S300).

The metal may be at least one of gold, silver, copper, palladium, nickel and platinum, and the metal film may be formed to a thickness of 0.1 to 100 nanometers (nm).

For example, the deposition step S300 will be described. The platinum thin film is deposited by sputtering the surface of the carbon nanotube layer for about 10 seconds.

Since charged particles in the plasma used for metal sputtering or sputter particles having high kinetic energy do not damage the carbon nanotube layer, productivity for manufacturing a conductive film may be improved.

Figure 3 is a flow chart showing another embodiment of the conductive film manufacturing method related to the present invention.

Referring to FIG. 3, the method for manufacturing a conductive film includes an affinity improving step (A100), a dispersion step (A200), a film forming step (A300), and a deposition step (A400).

The affinity improvement step (A100) improves the solvent affinity of carbon nanotubes through physical cutting or oxidation treatment. The physical cutting may be implemented by, for example, applying ultrasonic waves to carbon nanotubes. The oxidation treatment may, for example, oxidize the carbon nanotubes in a state where the carboxyl group is exposed.

The dispersing step (A200) disperses the carbon nanotubes in a solvent, and the film forming step (A300) forms a carbon nanotube film by coating the dispersion on a substrate. Next, a metal film is deposited on one surface of the carbon nanotube film through metal sputtering (A400).

If the conductive film is formed using only carbon nanotubes or metal thin films, an excessive amount of carbon nanotubes or a metal layer having a predetermined thickness is required to realize a certain level of electrical conductivity, thereby making it difficult to secure a certain level of transparency. Accordingly, when a thin metal film is formed on one surface of the carbon nanotube film through sputtering, the metal film can be easily formed on the carbon nanotube film regardless of the material and shape of the substrate. Through this, electrical conductivity is improved without loss of transparency, and the design and manufacturing tolerances of the conductive film can be increased.

4A and 4B are graphs showing the results of measuring sheet resistance and transparency of the conductive film manufactured by the method of manufacturing the conductive film of FIG. 2 or 3, respectively.

4A is a graph of surface resistance measured by a four-point probe method, and FIG. 4B is a UV-Vis-NIR spectrophotometer. It is a graph measuring the transparency.

Referring to FIG. 4A, the sheet resistance decreased by about 8 kohm / sq before and after sputtering. Referring to FIG. 4B, the transparency decreased by about 3% before and after sputtering. Through this, it can be seen that the conductive film is improved through the sputtering while the electrical conductivity is maintained.

The conductive film manufacturing method and the conductive film related to the present invention as described above is not limited to the configuration and method of the embodiments described above, the embodiments are all or part of each embodiment selectively so that various modifications can be made It may be configured in combination.

1 is a cross-sectional view showing an embodiment of a conductive film according to the present invention.

Figure 2 is a flow chart showing an embodiment of a conductive film manufacturing method related to the present invention.

Figure 3 is a flow chart showing another embodiment of the conductive film manufacturing method related to the present invention.

Figures 4a and 4b are graphs showing the results of measuring the sheet resistance and transparency of the conductive film produced by the conductive film manufacturing method of Figure 2 or 3, respectively.

Claims (13)

Dispersing carbon nanotubes in a solvent; Coating the dispersion on one surface of a substrate to form a carbon nanotube layer; And Conductive film manufacturing method comprising the step of depositing a metal film on one surface of the carbon nanotube layer through metal sputtering. The method of claim 1, A method of manufacturing a conductive film further comprising the step of pretreating carbon nanotubes through at least one of cutting and acid and chemical reaction. The method of claim 1, The solvent is at least one of N-methylpyrrolidone (NMP, N-methyl-2-pyrrolidone), dimethylacetamide (DMAc), dimethylformamide (DMF), cyclohexanone, ethyl alcohol, water and chlorobenzene Method for producing a conductive film, characterized in that. The method of claim 1, The metal is a conductive film production method, characterized in that at least one of gold, silver, copper, palladium, nickel and platinum. The method of claim 1, The metal film is a conductive film manufacturing method, characterized in that formed in a thickness of 0.1 to 100 nanometers (nm). The method of claim 1, The forming step, Vacuum filtration, self-assembly method, Langmuir-Blodgett method, solution casting method, bar coating method, dip coating method ), A method of manufacturing a conductive film, characterized in that the carbon nanotube layer is formed by any one of a spin coating method, a spray coating method and a roll-to-roll method. . The method of claim 1, And chemically treating the surface of the substrate so that the substrate is hydrophilic or hydrophobic. Light transmissive substrates; A carbon nanotube layer formed by coating a carbon nanotube dispersion on one surface of the substrate; And A conductive film comprising a metal film deposited to cover one surface of the carbon nanotube layer. The method of claim 8, The carbon nanotubes are made of at least one of a single wall, a double wall and a multiwall carbon nanotube. The method of claim 8, The metal film is formed of at least one of gold, silver, copper, palladium, nickel and platinum. The method of claim 8, The metal film is a conductive film, characterized in that formed in a thickness of 0.1 to 100 nanometers (nm). The method of claim 8, The light transmissive substrate is a conductive film, characterized in that formed of at least one of glass, quartz, synthetic resin and polymer material. Improving the solvent affinity of the carbon nanotubes by physically cleaving or oxidizing; Dispersing the carbon nanotubes in a solvent; Coating the dispersion on a substrate to form a carbon nanotube film; And Conductive film manufacturing method comprising the step of depositing a metal film on one surface of the carbon nanotube film through metal sputtering.

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