KR20160048546A - Conductive member and method for manufacturing the same - Google Patents

Abstract

A conductive member according to an embodiment of the present invention includes a base substrate, a conductive nano wire and a graphene layer formed on the base substrate, and a bonding layer formed between the base substrate and the graphene layer, and the conductive nano wire is located between the graphene layer and the bonding layer and at least a portion of the conductive nano wire is inserted into the bonding layer. Therefore, according to embodiments of the present invention, a conductive member having excellent electrical characteristics, that is, an excellent electrical conductivity can be manufactured without any loss of optical transmittance.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a conductive member and a manufacturing method thereof,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive member and a method of manufacturing the same, and more particularly, to a conductive member with improved electrical characteristics and a method of manufacturing the same.

BACKGROUND ART Transparent electrodes are used for electronic devices such as semiconductors, displays, and solar cells, and ITO (Indium Tin Oxide) films are mainly used as such transparent electrodes. However, ITO films are not easily broken by external impacts and are not flexible and can not be used in flexible next generation electronic devices. In addition, indium, which is a rare metal, is becoming depleted, and materials for replacing ITO films are required.

Transparent electrodes require low sheet resistance and high light transmittance. Among the substances meeting these conditions is Graphene. That is, Graphene is a material having a two-dimensional planar structure in which carbon atoms are connected in a honeycomb-like hexagonal shape, and has excellent electrical conductivity and light transmittance. In recent years, attempts have been made to replace transparent electrodes such as semiconductors, displays, and solar cells with indium tin oxide (ITO) films as graphene films.

Generally, a method for producing a graphene layer is as follows. First, at least one graphene layer is grown by chemical vapor deposition on a base substrate made of copper (Cu). Thereafter, a step of transferring the graphene layer onto a target substrate such as a PET substrate is performed. Such a transferring step requires a support capable of supporting the graphene thin film. More specifically, a PMMA (polymethylmethacrylate) support is formed on a graphene layer formed on one side of a base substrate. Then, the base substrate is removed by a method such as etching. Next, the graphene layer formed on the PMMA support is transferred again onto the target substrate, and then a complicated step of removing the PMMA support is performed. (See Korean Patent Publication No. 2011-0052300)

As described above, the graphene film has a complicated manufacturing process, difficulty in securing a sufficient electric conductivity, and weakness in external impact.

Korea Patent Publication No. 2011-0052300

The present invention provides a conductive member having excellent electrical conductivity while suppressing light transmission loss and a method of manufacturing the same.

The present invention provides a conductive member whose damage is suppressed or prevented, and which has excellent stability, and a method of manufacturing the same.

A conductive member according to an embodiment of the present invention includes a base substrate; A conductive nanowire and a graphene layer formed on the base substrate; And an adhesive layer formed between the base substrate and the graphene layer, wherein the conductive nanowire is positioned between the graphene layer and the adhesive layer, and at least a part of the conductive nanowire is inserted into the adhesive layer.

The length of the conductive nanowire may be longer than the average diameter of the grains of the graphene layer. A plurality of the conductive nanowires are provided, at least a part of the conductive nanowires directly contact the graphene layer, and at least a part of the graphene layer may directly contact the adhesive layer. In addition, a plurality of the conductive nanowires are provided, and the graphene layer has a plurality of crystal grains, and at least a part of the conductive nanowires may be disposed across the interface between the crystal grains.

The conductive nanowire may include at least one of silver, gold, copper, nickel, and at least one of the compounds, and the length of the conductive nanowire may be in the range of 5 to 150 mu m. The diameter of the conductive nanowire may range from 30 to 110 nm, and the ratio of the diameter to the length of the conductive nanowire may range from 50 to 1000: 1.

Meanwhile, the base substrate is light-transmissive and may include any one of glass, quartz, and a polymer resin. The graphene layer may be formed as a single layer or a plurality of layers, and the thickness of the graphene layer may range from 0.3 to 1.2 nm.

According to an aspect of the present invention, there is provided a method of manufacturing a conductive member, the method including: preparing a transfer substrate having a metal catalyst layer on one surface thereof; Forming a graphene layer on the metal catalyst layer; Coating the conductive nanowire on the graphene layer; Providing a base substrate having an adhesive layer on one surface thereof, and attaching the base substrate and the transfer substrate together; And removing the transfer substrate.

The process of forming the graphene layer may include chemical vapor deposition and the metal catalyst layer may include at least one of copper, nickel, iron, ruthenium, cobalt, platinum, palladium, molybdenum, gold and iridium or an alloy thereof can do. In addition, the solvent may include an alcohol-based material, and the content of the conductive nanowires may be in the range of 0.1 to 1 wt% with respect to the dispersion solution.

The transition substrate may be formed integrally with the metal catalyst layer or may be a separate material different from the metal catalyst layer. When the transition substrate is a separate material, the transition substrate may include any one of silicon, silicon oxide, and quartz can do.

The process of coating the conductive nanowires may include preparing a dispersion solution in which the conductive nanowires are dispersed in a solvent, and coating the dispersion solution on the graphene layer.

Also, the method includes coating the dispersion solution and then removing the solvent, and the dispersion solution coating process and the solvent removal process may be performed a plurality of times.

The step of attaching the base substrate and the transition substrate may include the step of contacting the adhesive layer with the conductive nanowire and the graphene layer, and applying pressure to at least one of the base substrate and the transition substrate.

The process of removing the metal catalyst layer and the transition substrate may include a process of preparing an etchant and a process of etching the metal catalyst layer using the etchant.

According to the embodiments of the present invention, since the conductive member is manufactured using the graphene layer and the conductive nanowire, a conductive member having excellent electrical characteristics, that is, electrical conductivity can be manufactured without loss of light transmittance. That is, the conductive nanowires are inserted between the graphene layer and the adhesive layer, and the conductive nanowires serve as bridges at the grain boundary of graphene, thereby improving the overall electrical conductivity.

The conductive nanowires provided in the conductive member are covered by the graphene layer, so that the nanowires are not exposed to the outside, so that the conductive nanowires can be inhibited or prevented from being oxidized.

When the adhesive layer is pressed onto the conductive nanowire and the graphene layer in the production of the conductive member, the adhesive layer is flexible with a polymer material, so that the conductive nanowire can be squeezed without damaging the conductive nanowire. Further, by using the adhesive layer, the conductive nanowires can be prevented from being separated from the lower substrate and the stability can be ensured.

In addition, since the graphene layer is formed by a chemical vapor deposition method in a conductive member, it can be coated over the entire surface, and uniformity of the coated thickness can be secured.

Further, since the conductive member of the embodiments of the present invention uses pure graphene instead of oxide graphene, a separate reduction process is not necessary, and the manufacturing process of the conductive member can be simplified.

1 is a cross-sectional view schematically showing a conductive member according to an embodiment of the present invention;
Fig. 2 is an enlarged cross-sectional view
FIG. 3 is a plan view showing a part of FIG.
4 is a view sequentially showing a method of manufacturing a conductive member according to an embodiment of the present invention
Figure 5 is a micrograph of a graphene layer taken in an embodiment of the present invention
FIG. 6 is a micrograph showing a structure in which a conductive nanowire is formed on a graphene layer according to an embodiment of the present invention. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of other various forms of implementation, and that these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know completely. In the drawings, thicknesses are exaggerated or enlarged to clearly illustrate the layers and regions, and the same reference numerals denote the same elements in the drawings.

FIG. 1 is an enlarged cross-sectional view of a portion of FIG. 1, and FIG. 3 is a plan view of a portion of FIG. to be.

1, a conductive member according to an embodiment of the present invention includes a base substrate 100, a conductive nanowire 400 formed on the base substrate 100, a graphene layer 300, a base substrate 100, The conductive nanowire 400 is disposed between the graphene layer 300 and the adhesive layer 200 and at least a part of the conductive nanowire 400 is inserted into the adhesive layer 200.

The base substrate 100 may be a light-transmitting material as a base material for holding various layers formed thereon. That is, the base substrate 100 is formed of a transparent polymeric resin such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyethersulfone (PES), polycyclic olefin (PCO) (PA), polyether ether ketone (PEEK), polyimide (PI), polymethyl methacrylate (PMMA), and cycloolefin copolymer (COC). The present invention is not limited thereto, and a substrate made of any one of glass, quartz, and metal may be used.

The graphene layer 300 refers to a thin sheet or a thin film made of graphene and is formed on the adhesive layer 200 to be described later. Here, graphene is a material having a two-dimensional planar structure connected in a honeycomb-like hexagonal shape, and may be a layer of graphite. Graphene is generally characterized by excellent electrical conductivity, thermal conductivity and translucency. The graphene layer 300 made of such graphene is formed of a plurality of layers in which a single layer or a single layer is repeatedly laminated, and the thickness of the entire graphene layer 300 can be in the range of 0.3 to 1.2 nm. At this time, the resistance of the graphene layer 300 is about 100 to 1000? / Sq. If the thickness of the graphene layer 300 is too small, it is very difficult to manufacture and it is difficult to secure the electrical conductivity. If the thickness of the graphene layer 300 is too large, it is difficult to secure the light transmittance.

The graphene layer 300 includes a plurality of grains G and has a very high electrical conductivity in each crystal grain. However, in the grain boundary (GB), which is the boundary between the grains, the electrical conductivity decreases sharply . Therefore, in the embodiment of the present invention, the conductive nanowires are provided to connect the plurality of grains G of the graphene layer 300. This will be described later.

The conductive nanowire 400 is fabricated into a fiber or rod shape using a material having excellent electrical conductivity, and a plurality of the conductive nanowires 400 are provided inside the conductive member. That is, a plurality of conductive nanowires 400 are positioned between the graphene layer 300 and the adhesive layer 200, and at least a portion thereof is inserted into the adhesive layer 200. 2, at least a part of the conductive nanowire 400 is in direct contact with the graphene layer 300, and the remaining part of the conductive nanowire 400 is inserted into the adhesive layer 200 to directly contact with the adhesive layer 200. In addition, at least a part of the graphene layer 300 directly contacts the adhesive layer 200. That is, a portion of the graphene layer 300 that does not contact the conductive nanowire 400 directly contacts the adhesive layer 200. The entire conductive nanowire 400 including the upper and lower portions is surrounded by the adhesive layer 200 and the graphene layer 300, and is not exposed to the outside.

At least some of the conductive nanowires 400 are disposed across the grain interface GB of the graphene layer 300. 3, the conductive nanowires 400 are disposed across the crystal grain interface GB of the graphene layer 300 to connect adjacent crystal grains G to each other. At this time, at least a part of the conductive nanowires 400 may be longer than the average diameter of the grain G of the graphene layer 300. When the conductive nanowire 400 is longer than the average diameter of the crystal grains G, the crystal grains G are closely connected and the crystal grains G other than the adjacent grains G can be connected. Of course, the short-length conductive nanowire 400 may be positioned directly above the crystal grain boundary GB to connect the crystal grains G. When the conductive nanowire 400 is bridged between the grains G of the graphene layer 300 or between the crystal grain boundaries, the conductive nanowire 400 serves as a conduction path for electrical conduction, The electric conductivity can be maintained, thereby improving the electric conduction characteristic of the conductive member. The arrangement of the conductive nanowires 400 in the horizontal direction is not particularly limited and may be any arrangement in which the conductive nanowires 400 can extend between graphene grains. That is, the conductive nanowires 400 may be arranged regularly or irregularly.

The conductive nanowire 400 may be made of a material containing at least one of silver, gold, copper, nickel, and at least one of these compounds. That is, the conductive nanowire 400 may be a single metal of at least one of silver, gold, copper, and nickel, or may be an alloy made of two or more of these metals. In addition, various kinds of metal materials may be used, and various materials having good electrical conductivity may be used.

The length of conductive nanowire 400 may range from 5 to 150 [mu] m. If the length of the conductive nanowire 400 is too small to be less than 5 μm, it can not sufficiently serve as a bridge connecting the graphene grains, and it is difficult to dispose a large amount of the conductive nanowires 400 on the conductive member . Also, at the intersection of the conductive nanowires 400, the flow of electrons is slowed due to the contact resistance at the intersection, which may cause an increase in the overall surface resistance. This is because as the amount of nanowires increases, the probability of the nanowires crossing each other increases. When the length of the conductive nanowire 400 is more than 150 μm, the conductive nanowire 400 may be warped and the workability may deteriorate.

The diameter of the conductive nanowire 400 may range from 30 to 110 nm. If the diameter of the conductive nanowire 400 is too small to be less than 30 nm, it can not sufficiently serve as a bridge connecting graphene grains. That is, when the conductive nanowire is manufactured, the length and diameter of the conductive nanowire are increased in proportion to each other. Therefore, when the diameter of the conductive nanowire is too small, the length of the conductive nanowire also decreases. If it is larger than 110 nm, too much light is scattered, thereby decreasing the light transmittance of the conductive member. In addition, the conductive nanowire 400 may have a diameter to length ratio ranging from 50 to 1000: 1.

The adhesive layer 200 is a layer that bonds or bonds between the base substrate 100 and the graphene layer 300 and between the base substrate 100 and the conductive nanowire 400. As the adhesive layer, a polymer resin may be used. The polymer is not particularly limited, and a thermoplastic polymer can be used, and in this case, no separate curing process is required. The polymer may be a thermosetting or photo-curable polymer. In this case, a separate process of curing by applying heat or irradiating light such as UV light may be performed. For example, the adhesive layer 200 may be formed by bonding the base substrate 100, the graphene layer 300, the base substrate 100, and the conductive nanowire 400 using a liquid state polymer having a predetermined viscosity, And becomes a bonding layer for bonding the upper and lower layers.

The polymer material may be at least one selected from the group consisting of an acrylic resin, an epoxy resin, a silicone resin, an ethylene vinyl acetate resin, a polyvinyl chloride resin, a polyurethane resin, a phenol resin, a polyester resin, a polyether resin, Based resin and a polyamide-based resin.

In the following, a manufacturing method for manufacturing a conductive member will be described. 4 is a view sequentially illustrating a method of manufacturing a conductive member according to an embodiment of the present invention.

A method of manufacturing a conductive member according to an exemplary embodiment of the present invention includes the steps of providing a transition substrate 900 having a metal catalyst layer 800 on one surface thereof and a process of forming a graphene layer 300 on the metal catalyst layer 800 A process of covering the conductive nanowire 400 on the graphene layer 300 may be performed by providing a base substrate 100 having an adhesive layer 200 on one surface thereof and attaching the base substrate 100 and the transition substrate 900 together And a process of removing the transfer substrate 900.

First, as shown in FIG. 4A, a transition substrate 900 having a metal catalyst layer 800 formed on one surface thereof is prepared. The transition substrate 900 may be formed integrally with the metal catalyst layer 800 or may be a separate material different from the metal catalyst layer 800. That is, the transition substrate 900 itself can serve as the metal catalyst layer 800 with a metal material, and the metal catalyst layer can be formed as a thin film on the transition substrate 900 using a separate substrate 900. When the transition substrate 900 is a separate material, the transition substrate 900 may include any one of silicon, silicon oxide, and quartz.

The metal catalyst layer 800 serves as a catalyst for growing the graphene layer 300 thereon, and the thickness of the graphene layer formed thereon can be adjusted according to the thickness of the catalyst layer. In addition, the metal catalyst layer 800 may include a metal material. For example, the metal catalyst layer 800 may include at least one of copper, nickel, iron, ruthenium, cobalt, platinum, palladium, molybdenum, gold and iridium or an alloy thereof. The metal catalyst layer 800 may be formed as a thin film on the transition substrate 900 and may have a thickness of several hundreds to several thousand nanometers.

Referring to FIG. 4 (b), a graphene layer 300 is formed on the metal catalyst layer 800. The process of forming the graphene layer 300 may be a chemical vapor deposition process. For example, after the transfer substrate 900 having the metal catalyst layer 800 is loaded on the deposition chamber, the chamber is adjusted to a proper vacuum pressure, the transfer substrate 900 is adjusted to an appropriate temperature, The process gas for growth is injected. In this case, the pressure at which the process proceeds may be in the range of 500 mtorr to 500 torr, the process progress temperature may be in the range of about 800 to 1000 ° C, and the process gas may be CH ₄ , C ₂ H ₂ , have. Through such a deposition process, graphene can be grown on the metal catalyst layer 800, and the graphene layer 300 can uniformly cover the entire lower layer. That is, the graphene layer 300 having a uniform thickness of a large area can be manufactured by the chemical vapor deposition method. Since the graphene layer 300 to be manufactured is pure graphene, a reduction process is not necessary afterwards.

Thereafter, as shown in FIG. 4C, the conductive nanowire 400 is coated on the upper portion of the graphene layer 300. The coating process may include preparing a dispersion solution in which the conductive nanowires are dispersed in a solvent, and coating the dispersion solution on the graphene layer 300. The solvent may include alcohol-based materials such as ethanol and methanol, and the content of the conductive nanowires with respect to the dispersion solution may range from 0.1 to 1% by weight. At this time, if the content of the conductive nanowires is too small, the viscosity of the dispersion solution is very low, so that the uniformity of the coated layer is low, and if the content is too high, the viscosity becomes too high to make coating difficult. The dispersion solution may be coated by various methods such as spray coating, bar coating, spin coating, and slot die coating.

After the dispersion solution in which the conductive nanowires are dispersed is coated on the graphene layer 300, the dispersion liquid, that is, the solvent is removed. The conductive nanowires 400 are disposed on the graphene layer 300. Here, the dispersion solution coating process and the solvent removal process may be repeated a plurality of times. That is, the coating can be repeated to control the amount of the conductive nanowires 400.

4 (d), a base substrate 100 having an adhesive layer 200 on one side, and a transition substrate 900 on which a graphene layer 300 and a conductive nanowire 400 are formed are bonded . That is, a liquid polymer resin is applied to the base substrate 100 to form an adhesive layer 200, which is placed on the transfer substrate 900 and the pressure is applied. The adhesive layer 200 is brought into contact with the conductive nanowire 400 and the graphene layer 300 and the pressure can be applied to at least one of the base substrate 100 and the transition substrate 900. At this time, since the adhesive layer 200 is in a liquid state, the upper and lower substrates adhere tightly to each other without damaging the conductive nanowire 400 even when pressure is applied. Also, at least a portion of the conductive nanowire 400 may be inserted into the interior of the adhesive layer 200.

As shown in FIG. 4 (e), the metal catalyst layer 800 and the transition substrate 900 are removed from the complex in which both substrates are bonded together. That is, the etching solution 10 is provided, and the metal catalyst layer 800 is etched by immersing the complex in the etching solution 10. When the metal catalyst layer 800 is removed, the transition substrate 900 is naturally removed from the base substrate 100. At this time, the etchant 10 is not particularly limited as long as it can dissolve and etch the metal catalyst layer 800. For example, ammonium persulfate (NH ₄ ) ₂ S ₂ O ₈ ), FeCl ₃ , HNO ₃ , KOH, HCl, HF and the like can be used as an etching solution.

4 (f), the base substrate 100, the adhesive layer 200, the conductive nanowires 400, and the graphene layer 300 (FIG. 4 ) Is obtained.

A structure in which a conductive nanowire is formed on a graphene layer and a graphene layer manufactured according to an embodiment of the present invention will be described below. FIG. 5 is a photomicrograph of a graphene layer taken in an embodiment of the present invention, and FIG. 6 is a photomicrograph of a structure in which conductive nanowires are formed on a graphene layer in an embodiment of the present invention.

A silicon wafer was used as a transfer substrate, and a copper layer was formed to a thickness of 1000 nm as a metal catalyst layer on the substrate. Then, chemical vapor deposition was carried out at a synthesis pressure of 500 mTorr and CH ₄ and H ₂ gases at 30 and 10 sccm, and graphene was synthesized and grown for about 20 minutes. A photograph of the surface of the graphene layer thus formed is shown in Fig. As shown in FIG. 5, the graphene layer has crystal grains, and a crystal grain interface GB appears between crystal grains.

The conductive nanowires were coated on the thus-prepared graphene layer using IPA (isopropylalcohol) dispersion solution in which 0.5 wt% of silver nanowires (AgNW) were dispersed. A photograph of the surface of the conductive nanowire-coated graphene layer is shown in FIG. As shown in FIG. 6, silver nanowires having a length of several to several tens of micrometers are arranged on the grains of the graphene layer. These silver nanowires serve as bridges connecting graphene grains and improve electrical conductivity.

Hereinafter, the characteristic results of the conductive member manufactured according to the embodiment of the present invention will be described. That is, in the conductive member manufactured according to the embodiment, the length and the diameter ratio of the silver nanowire to the diameter and length were varied, and the characteristics were compared.

First, a graphene layer was prepared under the above-mentioned conditions, and a silver nanowire dispersion solution having the respective conditions shown in Table 1 below was coated on the graphene layer to prepare a conductive member. The manufacturing process is the same as the above-described description as a whole, so redundant description is omitted.

In the experimental examples shown in Table 1, the conductive nanowires were coated four times using a dispersion solution in which 0.5 weight% of silver nanowires were dispersed in each graphene layer, and then bonded to a base substrate having an adhesive layer to prepare a conductive member. In Experimental Example 1, a silver nanowire having a length of 0.1 to 1 μm, a diameter of 25 nm, and a diameter to length ratio of 4 to 40 was used. In Experimental Example 2, the length was in the range of 20 to 50 μm, Silver nanowires having a diameter to length of 90 nm and a diameter to length of 222: 1 to 556: 1 were used. In Experimental Example 3, the length was in the range of 152 to 160 μm, the diameter was 150 nm, Silver nanowires with a ratio of 1013: 1 to 1067: 1 were used. In addition, the sheet resistance and light transmittance of the conductive member manufactured using the angle silver nanowires were measured.

AgNW
 Length (㎛) AgNW
 diameter( Nm ) Aspect ratio
(Length: diameter ) Sheet resistance
(Ω / □) Permeability (%) Experimental Example 1 0.1 to 1 25 4 to 40 31200 85.4 Experimental Example 2 20 to 50 90 222: 1 to 556: 1 61 91.2 Experimental Example 3 152 ~ 160 150 1013: 1 to 1067: 1 289 86.2

In all the experimental examples, the light transmittance was 85% or more, and when the length and the diameter of the silver nanowire were controlled to a predetermined range, the light transmittance could be improved while reducing the sheet resistance further. That is, when the silver nanowire of Experimental Example 2 was used, the sheet resistance was reduced to 61 Ω / □ and the light transmittance was improved to 91.2%.

On the other hand, using the silver nanowire having a length in the range of 20 to 50 mu m, a diameter of 90 nm and a diameter to length ratio of 222: 1 to 556: 1 as used in Experimental Example 2, The conductive member was prepared and properties were evaluated as shown in Table 2 below by varying the content of the conductive nanowires contained in the conductive member. The manufacturing process is the same as the above-described description as a whole, so redundant detailed description is omitted.

In Experimental Example 21, a dispersion solution having a conductive nanowire content of 0.05 wt% was used. In Experimental Example 22, a dispersion solution having a conductive nanowire content of 0.5 wt% was used. In Experimental Example 23, Was prepared using a dispersion solution having a wire content of 1.5% by weight. Each graphene layer was coated four times on the basis of the content of the conductive nanowires contained in the dispersion solution (Experimental Examples 21 to 23), followed by bonding to a base substrate having an adhesive layer to prepare a conductive member. In the comparative example, a graphene layer containing no silver nanowire was used. That is, for comparison with the experimental examples of the present invention, silver nanowires were not used, and only graphene was laminated in the same manner as in Experimental Examples 21 to 23 to prepare a conductive member. The sheet resistance and permeability of each of the prepared conductive members were measured. The sheet resistance was measured at nine different positions of the conductive member, and the sheet resistance measurement positions were selected at nine points arranged at the same interval in the region of the square shape.

AgNW  content
(weight%) Sheet resistance
(Ω / □) Permeability (%)
Experimental Example 21


0.05 wt%

112 103 126
90.9

116 162 169 167 117 117 Average: 132
Experimental Example 22


0.5 wt%

68 51 53
91.2

65 64 59 66 67 57 Average: 61
Experimental Example 23


1.5 wt%

88 99 65
89.3

79 117 98 74 102 105 Average: 92
Comparative Example


-

294 308 299
91.9

313 298 299 356 272 263 Average: 300

In all experimental examples, the sheet resistance was lower than 150 Ω / □ and the light transmittance was more than 89%. That is, the light transmittance is close to 90% while having a significantly lower sheet resistance value as compared with the comparative example in which silver nanowires are not included. In particular, when the content of the silver nanowires is controlled within a predetermined range, it is found that the light transmittance can be further improved while further reducing the sheet resistance. That is, when the silver nanowire of Experimental Example 22 was used, the average sheet resistance was reduced to 61? / ?, and the light transmittance was improved to 91.2%.

Although the technical idea of the present invention has been specifically described according to the above embodiments, it should be noted that the above embodiments are for explanation purposes only and not for the purpose of limitation. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention.

100: base substrate 200: adhesive side
300: graphene layer 400: conductive nanowire

Claims (19)

A base substrate;
A conductive nanowire and a graphene layer formed on the base substrate; And
And an adhesive layer formed between the base substrate and the graphene layer,
Wherein the conductive nanowire is positioned between the graphene layer and the adhesive layer, and at least a portion of the conductive nanowire is inserted into the adhesive layer.
The method according to claim 1,
Wherein the length of the conductive nanowire is longer than the average diameter of the grains of the graphene layer.
The method according to claim 1,
A plurality of the conductive nanowires are provided,
Wherein the conductive nanowire is at least partially in direct contact with the graphene layer,
Wherein the graphene layer is at least partially in direct contact with the adhesive layer.
The method according to claim 1,
A plurality of the conductive nanowires are provided,
Wherein the graphene layer has a plurality of crystal grains,
Wherein at least some of the conductive nanowires are disposed across the grain boundary.
The method according to any one of claims 1 to 4,
Wherein the base substrate is light transmissive and comprises any one of glass, quartz, and a polymeric resin.
The method according to any one of claims 1 to 4,
Wherein the conductive nanowire comprises at least one of silver, gold, copper, nickel, and at least one of the compounds.
The method of claim 6,
Wherein the conductive nanowires have a length in the range of 5 to 150 mu m.
The method of claim 7,
Wherein the conductive nanowires have a diameter in the range of 30 to 110 nm.
The method of claim 6,
Wherein the conductive nanowires have a diameter to length ratio ranging from 50 to 1000: 1.
The method according to any one of claims 1 to 4,
Wherein the graphene layer is formed of a single layer or a plurality of layers, and the thickness of the graphene layer is in a range of 0.3 to 1.2 nm.
Providing a transition substrate having a metal catalyst layer on one surface thereof;
Forming a graphene layer on the metal catalyst layer;
Coating the conductive nanowire on the graphene layer;
Providing a base substrate having an adhesive layer on one surface thereof, and attaching the base substrate and the transfer substrate together; And
And removing the transfer substrate.
The method of claim 11,
Wherein the step of forming the graphene layer includes a chemical vapor deposition method.
The method of claim 11,
The transition substrate may be formed integrally with the metal catalyst layer or may be a separate material different from the metal catalyst layer,
Wherein the transition substrate comprises any one of silicon, silicon oxide, and quartz when the transition substrate is a separate material.
The method according to any one of claims 11 to 13,
Wherein the metal catalyst layer comprises at least one of copper, nickel, iron, ruthenium, cobalt, platinum, palladium, molybdenum, gold and iridium or an alloy thereof.
The method of claim 11,
Wherein the step of coating the conductive nanowires comprises the steps of: preparing a dispersion solution in which the conductive nanowires are dispersed in a solvent; and coating the dispersion solution on the graphene layer.
16. The method of claim 15,
Wherein the solvent comprises an alcohol-based material, and the content of the conductive nanowires with respect to the dispersion solution is in the range of 0.1 to 1 wt%.
The method according to claim 15 or 16,
Coating the dispersion solution, and removing the solvent,
Wherein the dispersion solution coating process and the solvent removal process are performed a plurality of times.
The method of claim 11,
Wherein the step of bonding the base substrate and the transition substrate comprises the step of contacting the adhesive layer with the conductive nanowire and the graphene layer and applying pressure to at least one of the base substrate and the transition substrate Way.
The method of claim 11,
Wherein the process of removing the metal catalyst layer and the transition substrate comprises: preparing an etchant; and etching the metal catalyst layer using the etchant.

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