KR102066988B1 - The metamaterial structure for tunable plasmonic resonance and its fabrication method - Google Patents

Abstract

Herein is a substrate; A first metal composed of a nanopattern on the substrate; A second metal galvanic substituted on the outer surface of the first metal; Disclosed is a metamaterial structure comprising a coating layer composed of a second metal and a method of manufacturing the same.

Description

 The metamaterial structure for tunable plasmonic resonance and its fabrication method

The present invention relates to a metamaterial structure having an adjustable plasmonic resonance property and a method for manufacturing the same, and more particularly, to a metamaterial structure and a method for manufacturing the same, which can be easily adjusted through galvanic substitution.

When light enters the metamaterial on which the metal nanostructure is formed, the free electron density called plasmon vibrates collectively and absorbs a specific wavelength due to interaction with free electrons present in the metal. Applications in the field of nano-optics are underway. Since plasmonic properties have to be adjusted to suit the characteristics required for each application, researches on applying complex metal nanostructures have been conducted.

Therefore, in recent years, new plasmonic materials have been explored by controlling the physical properties of materials and improving performance of existing plasmonic applications. In other words, by using two or more materials combined with each other or diluted form (Cu-Ag, Pb-Rh, Ag-Au, etc.) beyond the optical properties of the existing pure metal surface enhancement Raman scattering (SERS), In order to improve the performance in the application fields of photoelectrode, catalyst, etc., the research was conducted.

However, most of the studied binary metals are made of nanoshells in the form of core-shells by a complex synthesis method, and thus there is a problem in that the conventional metamaterial manufacturing method is not complicated and simple.

In addition, although the developed nanoparticles are meaningful in themselves, the method of preparing metamaterials using binary metals was limited to specific shapes. In addition, there is a problem that the conventional meta-material manufacturing method is not universal by using a specific metal that is also limited to the metal used as the binary metal.

In addition, the developed nanoparticles are able to control the approximate plasmonic properties, but the process is complicated or difficult in most cases, there was a problem in the ease of plasmonic properties control.

Korea Patent Registration No. 10-1519500

The object of the present invention is the simplicity of controlling the plasmonic properties of metamaterial structures, without resorting to complex synthetic methods.

It is also an object of the present invention to be easy to apply to metamaterial structures, and to be versatile in that various metals can be constructed in the metamaterial structures.

In addition, an object of the present invention is the ease of adjustment that can adjust the plasmonic properties of the metamaterial structure simply and precisely.

As a means for achieving the above object is a substrate; A first metal composed of a nanopattern on the substrate; A second metal galvanic substituted on the outer surface of the first metal; Disclosed is a metamaterial structure comprising a coating layer composed of a second metal.

In each metamaterial structure of the present invention, the first metal and the second metal are silver (Ag), gold (Au), copper (Cu), aluminum (Al), nickel (Ni), chromium (Cr) or lead ( Each of at least one metal selected from the group consisting of Pb), and the second metal is preferably a higher reduction potential than the first metal.

In each metamaterial structure of the present invention, the thickness of the coating layer is preferably 1 nm or more and 200 nm or less.

In each metamaterial structure of the present invention, the atomic content ratio of the first metal and the substituted second metal is preferably 10: 1 or more and 10: 8 or less.

In each metamaterial structure of the present invention, it is preferable that the third to n-th metals are galvanically substituted on the outer surfaces of the second to n-th metals, respectively. (N is a natural number of 3 to 5)

In addition, the present specification as a means for achieving the above object (step 1) forming a substrate; (Second step) nanopatterning the first metal into a metal thin film on a substrate; (Third step) immersing the substrate and the first metal in an aqueous solution containing the second metal; (Fourth step) The meta-material structure manufacturing method comprising a; the outer surface of the first metal is galvanic substituted with the second metal to form a coating layer consisting of the second metal.

In each of the metamaterial structure production methods of the present invention, the temperature of the aqueous solution containing the second metal is preferably 60 ° C or more and 100 ° C or less.

In each metamaterial structure manufacturing method of the present invention, the thickness of the coating layer is preferably 1 nm or more and 200 nm or less.

In each of the metamaterial structure production methods of the present invention, the atomic content ratio of the first metal and the galvanic substituted second metal of the metal thin film is preferably 10: 1 or more and 10: 8 or less.

In each of the meta-material structure manufacturing method of the present invention, it is preferable that the third to n-th metal further comprises a galvanic substitution on the outer surface of the second to n-th metal, respectively. (N is a natural number of 3 to 5)

In addition, the present specification as a means for achieving the above object (step 1) forming a substrate; (Second step) nanopatterning the first metal on the substrate with at least one metal nanoparticle; (Third step) immersing the substrate and the first metal in an aqueous solution containing the second metal; (Fourth step) The meta-material structure manufacturing method comprising a; the outer surface of the first metal is galvanic substituted with the second metal to form a coating layer consisting of the second metal.

In each of the metamaterial structure manufacturing method of the present invention, it is preferable to further include the step of thermally sintering the coated metal nanoparticles after the second step to couple between the metal nanoparticles.

In the method for preparing each metamaterial structure of the present invention, it is preferable to further include coupling the metal nanoparticles by ligand substitution of the coated metal nanoparticles after the second step.

In each of the metamaterial structure production methods of the present invention, the temperature of the aqueous solution containing the second metal is preferably 60 ° C or more and 100 ° C or less.

In each metamaterial structure manufacturing method of the present invention, the thickness of the coating layer is preferably 1 nm or more and 200 nm or less.

In each of the metamaterial structure production methods of the present invention, the atomic content ratio of the first metal and the galvanic substituted second metal of the metal nanoparticles is preferably 10: 1 or more and 10: 8 or less.

In each of the meta-material structure manufacturing method of the present invention, it is preferable that the third to n-th metal further comprises a galvanic substitution on the outer surface of the second to n-th metal, respectively. (N is a natural number of 3 to 5)

The present invention is characterized by the simplicity of controlling the plasmonic properties of metamaterial constructs through simple galvanic substitution without resorting to complex synthetic methods.

In addition, the present invention is not limited to the shape and size of the metamaterial structure, and can be replaced uniformly, and the general purpose that various metals having a negative dielectric constant can be formed in the metamaterial structure is an advantage.

In addition, the present invention is characterized by the ease of adjustment that can easily and precisely control the plasmonic properties of the metamaterial structure according to the metal to be substituted through galvanic substitution.

1 is a schematic diagram of manufacturing a metamaterial structure using the galvanic substitution of the present invention.
2 is a structural diagram of a metal thin film-based metamaterial structure of the present invention.
FIG. 3 is a structural diagram of a metal thin film-based metamaterial structure in which a coating layer is formed by galvanic replacing an outer surface of an existing metal of FIG. 2.
4 is a structural diagram of a metal thin film-based metamaterial structure in which the outer surface of the metamaterial structure of FIG. 3 is galvanically substituted.
5 is a structural diagram of a metal nanoparticle-based metamaterial structure of the present invention.
FIG. 6 is a structural diagram of a metal nanoparticle-based metamaterial structure in which a coating layer is formed by galvanic replacing an outer surface of an existing metal of FIG. 5.
7 is a structural diagram of a metal nanoparticle-based metamaterial structure in which the outer surface of the metamaterial structure of FIG. 6 is galvanically substituted.
8 is a manufacturing diagram of the metal thin film-based metamaterial structure of the present invention.
9 is a manufacturing diagram of the metal nanoparticle-based metamaterial structure of the present invention.
FIG. 10 is a graph showing a ratio of substituted gold (Au) atoms to atoms of the entire metamaterial structure according to the substitution solution concentration and reaction time of the present invention.
FIG. 11 is a graph showing a change in the dielectric constant part of a metal thin film based metamaterial structure according to the substitution solution concentration and reaction time of Example 1 of the present invention.
12 is a graph showing the change in dielectric constant imaginary part of a metal thin film based metamaterial structure according to the substitution solution concentration and reaction time of Example 1 of the present invention.
FIG. 13 is a graph illustrating changes in plasmonic resonance characteristics of a metal nanoparticle-based metamaterial structure according to a substitution solution concentration and a reaction time of Example 2 of the present invention. FIG.
FIG. 14 is a graph illustrating changes in plasmonic resonance characteristics of metal nanoparticle-based metamaterial structures according to substitution solution concentration and reaction time of Example 2 of the present invention. FIG.
15 is a cross-sectional TEM image and EDX analysis results of Example 2 of the present invention.
16 is a graph showing changes in plasmonic resonance characteristics of the metal nanoparticle-based metamaterial structure according to Example 3 of the present invention.

The terminology used herein is for the purpose of describing particular examples only. Thus, for example, singular forms include plural forms unless the context clearly indicates that they are to be singular. In addition, the terms "comprise" or "comprise" as used in the present application are used to clearly indicate that there exists a feature, step, function, component, or a combination thereof described in the specification, and other features. It should be noted that it is not intended to preliminarily exclude the presence of elements, steps, functions, components, or combinations thereof.

On the other hand, unless defined otherwise, all terms used herein are to have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Accordingly, unless specifically defined herein, a particular term should not be construed in an excessively ideal or formal sense.

In addition, the terms "about", "substantially", and the like herein, are used at or near the numerical values when the manufacturing and material tolerances inherent in the meanings mentioned are given, and are accurate for the understanding of the present invention. Or absolute figures are used to prevent unfair use of unscrupulous infringers.

In addition, the "first" of the first metal of the present specification is added to distinguish from the second metal and should be interpreted to the extent that a person skilled in the art can clearly understand in the context of the entire specification. It is not interpreted otherwise.

In addition, the "existing metamaterial structure" of the present specification may be interpreted as a metamaterial structure including a first metal and a substrate.

In addition, the "metal thin film-based metamaterial structure" of the present specification may be interpreted as a metamaterial structure in which a first metal is deposited in the form of a metal thin film. In addition, in the context of the entire description, it can be extended to the extent that a person skilled in the art can clearly understand.

In addition, the "metal nanoparticle-based metamaterial structure" of the present specification may be interpreted as a metamaterial structure in which the first metal is coated in the form of metal nanoparticles. In addition, in the context of the entire description, it can be extended to the extent that a person skilled in the art can clearly understand.

In addition, the "substitution solution" of the present specification may be interpreted as a solution containing a galvanic substituted metal, and may be broadly interpreted in a range clearly understood by those skilled in the art in the context of the entire specification.

Hereinafter, the problem solving means of the present invention will be described in detail.

<Of the present invention Metamaterial  Structure>

Metamaterial structure of the present invention is a substrate; A first metal composed of a nanopattern on the substrate; A second metal galvanic substituted on the outer surface of the first metal; And a coating layer composed of a second metal. Hereinafter, each component constituting the metamaterial structure of the present invention will be described in detail.

The metamaterial structure of the present invention is formed by depositing or coating a first metal on a substrate. The substrate only needs to be capable of depositing or coating the first metal on the substrate in a micro or nano pattern, and is not particularly limited in material or shape of the substrate. The substrate may be a transparent material. For example, the substrate may comprise silicon (Si), glass, or transparent polymer.

First metal

The first metal of the present specification may be disposed on a substrate. In addition, the first metal may be disposed in a regular micro or nano pattern on the substrate, and there is no particular limitation on the method of disposing the first metal. Moreover, there is no restriction | limiting in particular also about the shape in which the 1st metal is arrange | positioned, and the magnitude | size. The first metal may be a metal having a negative dielectric constant for implementing plasmonic properties, and preferably, gold (Au), silver (Ag), aluminum (Al), nickel (Ni), chromium (Cr), or lead ( Pb), copper (Cu), and platinum (Pt) are mentioned.

The first metal may be disposed in a regular micro or nano pattern on the substrate. The first metal may be disposed two-dimensionally, and the disposed first metals may be spaced apart from each other by several nanometers (nm) to several hundred micrometers (μm) in a direction parallel to the upper surface of the substrate. Preferably, the arranged first metals may be spaced at equal intervals.

In addition, a method of disposing a first metal may be performed by depositing a first metal on a substrate using an e-beam evaporator, sputter, or the like. Another method of disposing a first metal may be a short ligand on a substrate. It can be done by connecting. When the first metal is deposited on the substrate, the metal thin film-based metamaterial structure may be formed, and when the first metal is connected with the short ligand on the substrate, the metal nanoparticle-based metamaterial structure may be formed.

In addition, the first metal is not limited in shape or size, and may be in various shapes such as cone, sphere, and wire in addition to the cylindrical shape disclosed as an example of the present specification. In the case of the cylinder disclosed as an example of the present specification, the diameter of the first metal may be several nanometers (nm) to several hundred micrometers (μm). The height of the first metal in a direction perpendicular to the upper surface of the substrate may be several nanometers (nm) to several hundred micrometers (μm). Also in other shapes, the length, width, diameter, etc. of the first metal in the horizontal direction from the upper surface of the substrate may be several nanometers (nm) to several hundred micrometers (μm). In addition, the height of the first metal in a direction perpendicular to the upper surface of the substrate may be several nanometers (nm) to several hundred micrometers (μm).

The first metal may be disposed on the substrate to form the metamaterial structure. In addition, the first metal outer surface of the metamaterial structure may be replaced with a second metal. Preferably, the metamaterial structure is immersed in the aqueous solution containing the second metal to replace the galvanic.

Second metal

The second metal of the present specification is a metal substituted with the outer surface of the first metal of the existing metamaterial structure consisting of the first metal and the substrate. By replacing the first metal with the second metal it is possible to control the plasmonic properties of the existing meta-material structure. As an example of the present invention, the existing metamaterial structure may be immersed in an aqueous solution containing a second metal to be galvanic substituted.

The second metal, which is substituted on the outer surface of the first metal of the existing metamaterial structure, may be a metal having a negative dielectric constant for plasmonic properties, and may include gold (Au), silver (Ag), aluminum (Al), and nickel (Ni). ), Chromium (Cr), lead (Pb), copper (Cu), platinum (Pt) and the like. Preferably, the second metal may be galvanically substituted with the first metal by a metal having a higher reduction potential than the first metal, and is not limited to the examples described below. For example, when the first metal is aluminum (Al), the second metal is chromium (Cr), nickel (Ni), lead (Pb), copper (Cu), silver (Ag), platinum (Pt), gold (Au) This can be For example, when the first metal is chromium (Cr), the second metal may be nickel (Ni), lead (Pb), copper (Cu), silver (Ag), platinum (Pt), or gold (Au). For example, when the first metal is nickel (Ni), the second metal may be lead (Pb), copper (Cu), silver (Ag), platinum (Pt), or gold (Au). For example, when the first metal is lead (Pb), the second metal may be copper (Cu), silver (Ag), platinum (Pt), and gold (Au). For example, when the first metal is copper (Cu), the second metal may be silver (Ag), platinum (Pt), or gold (Au). For example, when the first metal is silver (Ag), the second metal may be platinum (Pt) or gold (Au). For example, when the first metal is platinum (Pt), the second metal may be gold (Au).

Further, the second metal is more preferably a metal having the same lattice structure as the first metal. The second metal has the same lattice structure as the first metal, so that galvanic substitution occurs better. Gold (Au), silver (Ag), aluminum (Al), nickel (Ni), lead (Pb), copper (Cu), and platinum (Pt) have a face centered cubic structure (FCC structure).

For example, when the first metal is aluminum (Al), the second metal may be nickel (Ni), lead (Pb), copper (Cu), silver (Ag), platinum (Pt), or gold (Au).

For example, when the first metal is nickel (Ni), the second metal may be lead (Pb), copper (Cu), silver (Ag), platinum (Pt), or gold (Au).

For example, when the first metal is lead (Pb), the second metal may be copper (Cu), silver (Ag), platinum (Pt), and gold (Au).

For example, when the first metal is copper (Cu), the second metal may be silver (Ag), platinum (Pt), or gold (Au).

For example, when the first metal is silver (Ag), the second metal may be platinum (Pt) or gold (Au).

For example, when the first metal is platinum (Pt), the second metal may be gold (Au).

The second metal of the present invention can be controlled by the plasmonic properties of the existing meta-material structure by being substituted with the first metal. For example, when silver (Ag) is replaced with gold (Au) as an example of the present invention, when the gold (Au) content of the metamaterial structure is increased, the plasmonic resonance characteristic is shifted toward the longer wavelength. In addition, when silver (Ag) is substituted with platinum (Pt) as an example of the present invention, when the platinum (Pt) content of the metamaterial structure is increased, the plasmonic resonance characteristic is shifted toward the shorter wavelength. Metamaterial structure of the present invention can adjust the plasmonic properties of the existing metamaterial structure according to the second metal to be substituted.

The second metal of the present invention is a metal substituted with the first metal on the outer surface of the first metal of the existing metamaterial structure. Preferably, the metamaterial structure is immersed in the solution containing the second metal to replace the galvanic. More preferably, it may be immersed in the aqueous solution contained in the second metal, the temperature of the aqueous solution may be 60 ℃ or more and 100 ℃ or less. Below 60 ° C., the second metal is not uniformly substituted on the outer surface of the first metal. Above 100 ° C., the aqueous solution containing the second metal boils and the galvanic substitution is limited. Even more preferably, the temperature of the aqueous solution may be 70 ° C or more and 90 ° C or less. Above 70 ° C., the second metal to be substituted diffuses into the existing metamaterial structure so that the second metal is uniformly substituted on the outer surface of the first metal. Above 90 ° C, bubbles are generated in the aqueous solution containing the second metal, so that the galvanic substitution is limited. Most preferably, the temperature of aqueous solution is 80 degreeC. At 80 ° C., the second metal to be substituted diffuses into the existing metamaterial structure so that the second metal is uniformly substituted on the outer surface of the first metal, and bubbles are not generated in the aqueous solution containing the second metal, so the galvanic substitution is well performed. Is done.

The first metal and the second metal of the present invention are not limited to the examples listed above as metals having a negative dielectric constant capable of realizing plasmonic properties. Therefore, the first metal and the second metal may be interpreted as various metals having negative permittivity. The present invention has the advantage that it can utilize a variety of metal having a negative dielectric constant as the first metal, the second metal.

On the other hand, as a result of the substitution of the second metal on the outer surface of the first metal, a coating layer consisting of the second metal can be formed. Coating layer in the present invention corresponds to the configuration to control the plasmonic properties.

Coating layer

As a result of replacing the first metal outer surface of the present invention with the second metal, a coating layer including the second metal may be formed. Adding the coating layer to the existing metamaterial structure, it is possible to control the plasmonic properties of the existing metamaterial structure. The metamaterial structure of the present invention has a feature of forming a coating layer through a simple solution process and controlling the plasmonic properties of the existing metamaterial structure with the formed coating layer.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail. However, the present invention is provided to be easily implemented by those skilled in the art, and the present invention can be embodied in many different forms, and the spirit of the present invention is necessarily limited to the following description. It is not.

1 is a simplified diagram of a process for forming a metamaterial structure of the present invention. The left figure and the right figure based on the arrow show the existing meta material structure 20 made of the substrate 10 and the first metal, and the existing meta material structure 20 is immersed in the solution 40 containing the second metal. The metamaterial structure 30 in which the first metal outer surface of the material structure 20 is galvanically substituted with the second metal.

2 is a metal thin film based metamaterial structure 200. The metamaterial structure 200 in which the first metal is deposited in the form of a thin film on the substrate 10. 2, the left and right diagrams show top and side cross-sectional views of the metamaterial structure 200, respectively. 3 is a metamaterial structure in which an outer surface of the first metal of FIG. 2 is replaced with a second metal 300. The second metal 300 may form a coating layer on the outer surface of the first metal as shown in FIG. The left and right figures of FIG. 3 show top and side cross-sectional views of the metamaterial structure, respectively. In FIG. 4, the metamaterial structure of FIG. 3 is galvanic substituted, and the metamaterial structure is double-substituted with the second metal 300 and the third metal 310 on the outer surfaces of the first metal and the second metal 300, respectively. . The left and right figures of FIG. 4 show top and side cross-sectional views of the metamaterial structure, respectively. The reduction potential of the second metal 300 is higher than that of the first metal, and the reduction potential of the third metal 310, which is the metal substituted in FIG. 4, is higher than that of the second metal 300.

5 is a metal nanoparticle based metamaterial structure 400. The metamaterial structure 400 is coated with a first metal in the form of nanoparticles 500 on the substrate 10. The left figure and the right figure of FIG. 5 show top and side cross-sectional views of the metamaterial structure 400, respectively. FIG. 6 is a metamaterial structure in which an outer surface of the first metal 500 of FIG. 5 is replaced with a second metal 300. As shown in FIG. 6, the second metal 300 may form a coating layer on the outer surface of the first metal 500. The left figure and the right figure of FIG. 6 show top and side cross-sectional views of the metamaterial structure, respectively. In FIG. 7, the metamaterial structure of FIG. 6 is galvanic substituted, and meta is double substituted by the second metal 300 and the third metal 310 on the outer surfaces of the first metal 500 and the second metal 300, respectively. It is a material structure. The left figure and the right figure of FIG. 7 show top and side cross-sectional views of the metamaterial structure, respectively. The second metal 300 has a higher reduction potential than the first metal 500, and the third metal 310, which is a metal substituted in FIG. 7, has a higher reduction potential than the second metal 300.

The coating layer of the present invention can control the plasmonic properties in addition to the existing meta-material structure.

Preferably, the thickness of a coating layer is 1 nm or more and 200 nm or less. If the thickness is less than 1nm, the coating layer is too thin so there is no change in the plasmonic properties of the existing metamaterial structure. If the thickness is 200nm or more, the coating layer is too thick so that the plasmonic properties of the first metal can be realized outside the metamaterial structure. none.

More preferably, the coating layer may adjust the plasmonic properties when the atomic content ratio of the first metal and the substituted second metal of the existing metamaterial structure is 10: 1 or more and 10: 8 or less. At less than 10: 1, there is no change in the plasmonic properties of the existing metamaterial structures because there are too few substituted metals. If at 10: 8 or more, there are too many substituted metals to lose the plasmonic properties of the existing metamaterial structures. The plasmonic properties of the metal become the plasmonic properties of the metamaterial structure.

The thickness and atomic content ratio of the coating layer of the present invention is determined according to the galvanic substitution, and the degree of galvanic substitution may be controlled by adjusting the concentration of the substitution solution, the reaction time, and the like. The atomic content ratio increases exponentially with the concentration of the substitution solution and the reaction time, and decreases as the concentration of the substitution solution and the reaction time increase.

Galvanic substitution in the present invention as well as in the case of the double-substituted metamaterial structures of FIGS. 4 and 7 may be substituted two or more times, wherein the third to nth metals are respectively on the outer surface of the second to n-1 metals. Galvanic substitution may be made. (N is a natural number of 3 or more.) Preferably, n is a natural number of 3 or more and 5 or less. When n is 3 or more, the galvanic substitution may be performed two or more times, so that the coating layer may be composed of two or more plural layers, thereby enabling more precise control of the plasmonic properties. On the other hand, when n is 5 or more, the thickness of the coating layer that can be formed in the shape of the existing metamaterial structure is limited, so there is a physical limit, so that the galvanic substitution occurs inefficiently.

As described above, the coating layer may be composed of two or more layers by performing galvanic substitution two or more times. For example, when silver (Ag) is replaced with platinum (Pt) and then platinum (Pt) is replaced with gold (Au) as an example of the present invention, platinum (Pt) of the metamaterial structure is substituted by platinum (Pt). As the content is increased, the plasmonic resonance characteristic is shifted toward the shorter wavelength. After gold (Au) is substituted, the plasmonic resonance characteristic is shifted to the longer wavelength as the gold (Au) content of the metamaterial structure is increased. As in the above-described example, when forming two or more coating layers than one coating layer, it is possible to adjust the plasmonic properties more precisely by combining them properly.

Combination Aspects and Specific Effects

The coating layer of the present invention consists of a second metal in which the outer surface of the first metal is galvanically substituted with the second metal as a result of infiltrating the existing meta-material structure in the substitution solution. The coating layer may adjust the plasmonic properties of the existing metamaterial structure according to its thickness and atomic content ratio, and may be composed of two or more layers through double and multiple substitutions as well as a single substitution.

In addition, the thickness of the coating layer, the atomic content ratio is determined according to the galvanic substitution, it is possible to control the degree of galvanic substitution by adjusting the concentration of the substitution solution, the reaction time. The atomic content ratio increases exponentially with the concentration of the substitution solution and the reaction time, and the increase decreases as the concentration of the substitution solution and the reaction time increase. An advantage of the present invention is the simplicity of the existing meta-material structure formed by infiltrating the substitution solution, and simply controlling the plasmonic properties of the meta-material structure by adjusting the concentration and reaction time of the substitution solution.

The second metal is a galvanic substituted metal with the first metal outer surface of the existing metamaterial structure. Preferably, the existing meta-material structure is immersed in the substitution solution containing the second metal so that the first metal may be galvanically substituted with the second metal. Since the metamaterial structure of the present invention is substituted from the outer surface of the first metal exposed to the substitution solution, the metamaterial structure is not limited to the shape and size of the existing metamaterial structure, and thus uniform substitution is possible. In addition, the first metal and the second metal of the present invention may be a metal having a negative dielectric constant capable of realizing plasmonic properties, and are not limited to the examples listed above. Therefore, the first metal and the second metal may be interpreted as various metals having negative permittivity. Advantages of the manufacturing method of the present invention is not limited to the shape and size of the existing meta-material structure, and can be replaced uniformly, and can be applied to various metals having a negative dielectric constant.

The existing metamaterial structure consisting of the first metal and the substrate corresponds to the metamaterial structure having the minimum requirements for realizing plasmonic properties. The metamaterial structure of the present invention may control the plasmonic properties by replacing the first metal outer surface of the existing metamaterial structure with another metal. For example, when silver (Ag) is replaced with gold (Au) as an example of the present invention, when the gold (Au) content of the metamaterial structure is increased, the plasmonic resonance characteristic is shifted toward the longer wavelength. In addition, when silver (Ag) is substituted with platinum (Pt) as an example of the present invention, when the platinum (Pt) content of the metamaterial structure is increased, the plasmonic resonance characteristic is shifted toward the shorter wavelength. An advantage of the present invention is the controllability of controlling the plasmonic properties of the existing metamaterial structure according to the metal to be substituted.

<Method for producing meta-material structure of the present invention>

8 is a manufacturing diagram of the metal thin film-based metamaterial structure of the present invention. The metal thin film-based metamaterial structure of the present invention comprises the steps of forming a substrate, followed by nanopatterning a first metal into a thin metal film on the substrate, and then submerging the substrate and the first metal in an aqueous solution containing a second metal. Next, the outer surface of the first metal is galvanically substituted with the second metal to form a coating layer formed of the second metal.

9 is a manufacturing diagram of the metal nanoparticle-based metamaterial structure of the present invention. The metal nanoparticle-based metamaterial structure of the present invention comprises the steps of forming a substrate, followed by nanopatterning the first metal on the substrate with at least one metal nanoparticle, followed by the substrate and the first metal as the second metal. Submerged in an aqueous solution containing, and then the outer surface of the first metal is galvanic substituted with the second metal to be prepared through the step of forming a coating layer composed of the second metal.

That is, the method of manufacturing a metamaterial structure of the present invention comprises the steps of forming a substrate; Nanopatterning the first metal on the substrate; Immersing the substrate and the first metal in a solution comprising the second metal; And an outer surface of the first metal to be galvanically substituted with the second metal to form a coating layer composed of the second metal. Hereinafter, each step will be described in detail.

Forming a substrate

In the present invention, the first metal is nanopatterned and immersed in a solution including the second metal together with the patterned first metal. In order to maintain the patterned state of the first metal in the nanopattern, the substrate does not react with the solution containing the second metal without reacting with the first metal, and is not limited thereto. As an example of the substrate, preferably, a glass substrate, a substrate based on a transparent polymer, may be mentioned.

Nanopatterning the first metal on the substrate

Nano-patterning the first metal in the present invention is sufficient to pattern the first metal on the substrate in a nano-pattern, and not limited to other limitations. Hereinafter, a nanopatterning technique for patterning a first metal on a substrate with a nanopattern will be described. The nanopatterning technique described below is merely illustrative of the present invention and the present invention is not limited to the following description.

Patterning methods include, for example, electron beam lithography (E-beam lithography), nano imprint (nano imprint), and the like.

For example, nanoimprints may include, for example, hard lithography, soft lithography, and the like.

For example, hard lithography may include, for example, thermal imprinting (hot embossing) and UV imprinting.

Soft lithography, for example, may include, for example, microcontact printing (μCP), decal transfer microlithography (DTM), printing of light stamps, and the like, replica molding, capillary force lithography ( capillary force lithography, micromolding in capillaries (MIMIC), microtransfer molding (μTM), nanoimprinting, liquid-bridgemediated nanotransfer molding (LB-nTM), etc. Can be mentioned.

In addition, a method in which the first metal is deposited in the form of a metal thin film or the method of coating in the form of metal nanoparticles may be sufficient as an array of nanopatterns, and is not limited thereto.

For example, in the case of the deposition method, for example, chemical vapor deposition (CVD) and physical vapor deposition (Physical Vapor Deposition, PVD) may be mentioned. For example, chemical vapor deposition includes, for example, atmospheric chemical vapor deposition (APCVD), low pressure chemical vapor deposition (LPCVD), plasma chemical vapor deposition (PECVD), and the like.

For example, physical vapor deposition includes, for example, thermal evaporation, electron beam evaporation, sputtering, and the like.

In addition, in the case of the method of coating, the method of coating directly, the method of coating after surface modification, etc. are mentioned, for example.

Immersing the substrate and the first metal in a solution comprising the second metal

The present invention infiltrates the substrate and the first metal into a solution containing the second metal to galvanically replace the outer surface of the first metal with the second metal. Existing metamaterial structures of the substrate and the first metal are completely submerged in a solution comprising the second metal.

The solution including the second metal is a solution containing a metal having a higher dielectric constant than the first metal while having a negative dielectric constant, and may be various types of solutions. However, the second metal is not to be construed as being limited to the examples listed below.

For example, when the second metal substituted with the first metal is aluminum (Al), various salts including a single metal ion and aluminum are possible. For example, aluminum phosphate, aluminum fluoride salt, etc. are mentioned.

For example, when the second metal to be substituted with the first metal is chromium (Cr), various salts including a single metal ion, chromium, are possible. For example, chromate, chromate peroxide, chromate cyanate, etc. are mentioned.

For example, when the second metal to be substituted with the first metal is nickel (Ni), various salts including single metal ions and nickel are possible. For example, tetracyano nickel acid salt, nickel acid salt, etc. are mentioned.

For example, when the second metal to be substituted with the first metal is lead (Pb), various salts including a single metal ion and lead are possible. For example, lead bromide, lead chloride, etc. are mentioned.

For example, when the second metal to be substituted with the first metal is copper (Cu), various salts are possible including a single metal ion, copper. For example, tetracyano copper salt, trichloro copper salt, a copper sulfate salt, etc. are mentioned.

For example, when the second metal substituted with the first metal is silver (Ag), various salts including a single metal ion, silver, are possible. For example, trichloro nitrate, triiodo nitrate, diaceta nitrate, etc. are mentioned.

For example, when the second metal to be substituted with the first metal is platinum (Pt), various salts including a single metal ion, platinum, are possible. For example, chloroplatinum salt etc. can be mentioned.

For example, when the second metal to be substituted with the first metal is gold (Au), various salts including a single metal ion and gold are possible. For example, cyano gold salt, a gold chloride salt, etc. are mentioned.

In addition, the solution containing the second metal of the present invention may preferably be an aqueous solution. More preferably, the temperature of aqueous solution is 60 degreeC or more and 100 degrees C or less. Below 60 ° C., the second metal is not uniformly substituted on the outer surface of the first metal. Above 100 ° C., the aqueous solution containing the second metal boils and the galvanic substitution is limited. Even more preferably, the temperature of the aqueous solution may be 70 ° C or more and 90 ° C or less. Above 70 ° C., the second metal to be substituted diffuses into the existing metamaterial structure so that the second metal is uniformly substituted on the outer surface of the first metal. Above 90 ° C, bubbles are generated in the aqueous solution containing the second metal, so that the galvanic substitution is limited. Most preferably, the temperature of aqueous solution is 80 degreeC. At 80 ° C., the second metal to be substituted diffuses into the existing metamaterial structure so that the second metal is uniformly substituted on the outer surface of the first metal, and bubbles are not generated in the aqueous solution containing the second metal, so the galvanic substitution is well performed. Is done.

The first metal is immersed in a solution containing the second metal so that the outer surface of the first metal is galvanically substituted with a second metal having a higher reduction potential. As a result of the galvanic substitution, a coating layer composed of the second metal may be formed. Hereinafter, the step of forming the coating layer will be described.

The outer surface of the first metal is the second metal Galvanic  Substituting to form a coating layer consisting of a second metal

As a result of infiltrating the existing meta-material structure into the substitution solution, the outer surface of the first metal may form a coating layer composed of the second metal galvanically substituted with the second metal. The coating layer may adjust the plasmonic properties of the existing metamaterial structure according to its thickness and atomic content ratio, and may be composed of two or more layers through double and multiple substitutions as well as a single substitution. In addition, the thickness of the coating layer, the atomic content ratio is determined according to the galvanic substitution, it is possible to control the degree of galvanic substitution by adjusting the concentration of the substitution solution, the reaction time. The atomic content ratio increases exponentially with the concentration of the substitution solution and the reaction time, and the increase decreases as the concentration of the substitution solution and the reaction time increase. The present invention is formed by the existing meta-material structure is immersed in the substitution solution, it is possible to simply control the plasmonic properties of the meta-material structure by adjusting the concentration, the reaction time of the substitution solution.

The coating layer of the present invention is formed in addition to the existing meta-material structure can control the plasmonic properties. Preferably, the thickness of a coating layer is 1 nm or more and 200 nm or less. If the thickness is less than 1nm, the coating layer is too thin so there is no change in the plasmonic properties of the existing metamaterial structure. If the thickness is 200nm or more, the coating layer is too thick so that the plasmonic properties of the first metal can be realized outside the metamaterial structure. none.

More preferably, the coating layer may adjust the plasmonic properties when the atomic content ratio of the first metal and the substituted second metal of the existing metamaterial structure is 10: 1 or more and 10: 8 or less. At less than 10: 1, there is no change in the plasmonic properties of the existing metamaterial structures because there are too few substituted metals. If at 10: 8 or more, there are too many substituted metals to lose the plasmonic properties of the existing metamaterial structures. The plasmonic properties of the metal become the plasmonic properties of the metamaterial structure.

<Meta substance structure produced by the manufacturing method of the present invention>

Simplicity of Fabrication of Metal Nanoparticle-Based Metamaterial Structures

The coating layer of the present invention consists of a second metal in which the outer surface of the first metal is galvanically substituted with the second metal as a result of infiltrating the existing meta-material structure in the substitution solution. The coating layer may adjust the plasmonic properties of the existing metamaterial structure according to its thickness and atomic content ratio, and may be composed of two or more layers through double and multiple substitutions as well as a single substitution. In addition, the thickness of the coating layer, the atomic content ratio is determined according to the galvanic substitution, it is possible to control the degree of galvanic substitution by adjusting the concentration of the substitution solution, the reaction time. The atomic content ratio increases exponentially with the concentration of the substitution solution and the reaction time, and decreases as the concentration of the substitution solution and the reaction time increase. An advantage of the present invention is the simplicity of the existing meta-material structure formed by immersing in the substitution solution and simply controlling the plasmonic properties of the meta-material structure by adjusting the concentration and reaction time of the substitution solution.

Generality of the Structure of Metamaterial Structures

The production method of the present invention can be galvanic substitution by infiltrating the existing meta-material structure in the substitution solution. Since the second metal is substituted from the outer surface of the first metal exposed to the substitution solution, uniform substitution is possible without being limited to the shape and size of the existing metamaterial structure. In addition, the first metal and the second metal of the present invention are not limited to the examples listed above as metals having a negative dielectric constant capable of realizing plasmonic properties. Therefore, the first metal and the second metal may be interpreted as various metals having negative permittivity. Advantages of the present invention are not limited to the shape and size of the existing metamaterial structure, and can be uniformly substituted, and can be applied to various metals having a negative dielectric constant.

Ease of controlling plasmonic properties of metamaterial structures

The existing metamaterial structure consisting of the first metal and the substrate corresponds to the metamaterial structure having the minimum requirements for realizing plasmonic properties. The manufacturing method of the present invention can control the plasmonic properties by galvanic replacement of the first metal outer surface of the existing metamaterial structure with other metals. For example, when silver (Ag) is replaced with gold (Au) as an example of the present invention, when the gold (Au) content of the metamaterial structure is increased, the plasmonic resonance characteristic is shifted toward the longer wavelength. In addition, when silver (Ag) is substituted with platinum (Pt) as an example of the present invention, when the platinum (Pt) content of the metamaterial structure is increased, the plasmonic resonance characteristic is shifted toward the shorter wavelength. An advantage of the present invention is the controllability of controlling the plasmonic properties of the existing metamaterial structure according to the metal to be substituted.

Coupling of Metal Nanoparticle-based Metamaterial Structures

The metal nanoparticle-based metamaterial structure manufactured by the method of the present invention has the property of thermally sintering metal nanoparticles or substituting them with chemically short ligands to electromagnetically couple between nanoparticles. This makes it possible to better implement the plasmonic characteristics.

{Example}

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is provided to be easily implemented by those skilled in the art, and the present invention may be embodied in many different forms, and the spirit of the present invention is not necessarily limited to the embodiments. no.

FIG. 10 is the total atomic content substitution when silver (Ag) is galvanically substituted with gold (Au) according to the concentration of aqueous solution of HAuCl ₄ (0.007mM, 0.014mM, 0.035mM) and reaction time (10, 30, 60 minutes). It is a graph showing the atomic content ratio of gold. The atomic content ratio increases exponentially with the concentration of the substitution solution and the reaction time, and the increase is decreased as the concentration of the substitution solution and the reaction time increase.

Example  1: metal thin film base Metamaterial  Structure

Each manufacturing step of Example 1 will be described in detail below.

Step (A) In the step of forming the substrate, the substrate of the present invention used a glass substrate, a transparent polymer substrate and the like.

Step (B) In the step of uniformly coating the (polymer) resin to increase the monolayer in order to form a nano-pattern on the substrate, the resin 600 used a photoresist (PR), polymethyl glutarimide (PMGI).

(C) step of uniformly coating the resin of the micro- or nano-pattern directly on the substrate or uniformly on the resin of the second step, the resin can be heat or UV curable (Hydrofen silsesquioxane) or polybutyl meta Polymer resins such as acrylate (PBMA) and polymethyl methacrylate (PMMA) were used.

Step (D) is a step of contacting the stamp mold of the micro or nanopattern, applying a constant pressure and processing according to heat or UV curing, the stamp mold used a polymer-based material made of polydimethylsiloxane (PDMS) or the like.

Step (E) In the step of separating the stamp mold to form a micro pattern or a nano pattern of the resin, the remaining layer of the resin in contact with the stamp mold was removed.

Step (F) In the step of depositing the metal thin film between the patterns, the metal thin film is silver (Ag), and sputtering was used as the vapor deposition method.

Step (G) The (polymer) resin structures 600 and 610 were removed to selectively leave only a pattern made of a metal thin film, which was removed with a chemical solution.

(H) step of galvanic substitution in order to control the physical properties of the formed metamaterial structure, the metamaterial structure of silver (Ag) is immersed in an aqueous solution of HAuCl _{4 having} an aqueous solution temperature of 80 degrees silver (Ag) The outer surface was galvanic substituted with Au.

A silver metal thin film based metamaterial structure was formed according to the above-described manufacturing procedure, and the silver (Ag) of the structure was changed according to the concentration of the aqueous solution of HAuCl ₄ (0.007 mM, 0.035 mM) and the reaction time (10, 30, 60 minutes). ) The outer surface was galvanically substituted with Au.

Example  2: metal nanoparticle base Metamaterial  Structure

Each manufacturing step of Example 2 will be described in detail below.

Step (a) In the step of forming a substrate, the substrate of the present invention used a glass substrate, a transparent polymer substrate and the like.

(B) step of uniformly coating the (polymer) resin to increase the monolayer to form a nano-pattern on the substrate, the resin used a photoresist (PR), polymethyl glutarimide (PMGI).

(C) step of uniformly coating the resin of the micro- or nano-pattern directly on the substrate or uniformly on the resin of the second step, the resin may be heat or UV-curable HSQ (Hydrofen silsesquioxane) or polybutyl meta Polymer resins such as acrylate (PBMA) and polymethyl methacrylate (PMMA) were used.

Step (d) Contacting the stamp mold of the micro or nanopattern, applying a constant pressure, and treating with heat or UV curing, the stamp mold used a polymer-based material made of polydimethylsiloxane (PDMS) or the like.

Step (ㅁ) In the step of separating the stamp mold to form a micro pattern or a nano pattern of the resin, the remaining layer of the resin in contact with the stamp mold was removed.

(Iii) coating the metal nanoparticles between the patterns, wherein the metal nanoparticles were silver (Ag).

(G) step (polymer ) The step of removing the resin structure to selectively leave only the pattern consisting of metal nanoparticles, was removed with a chemical solution.

Step (o) The metal nanoparticles constituting the metamaterial structure were thermally sintered or replaced with chemically short ligands to couple the nanoparticles.

(B) step of galvanic substitution in order to control the physical properties of the formed metamaterial structure, the metamaterial structure of silver (Ag) is immersed in an aqueous solution of HAuCl _{4 having} an aqueous solution temperature of 80 degrees silver (Ag) The outer surface was galvanic substituted with Au.

According to the manufacturing procedure described above, silver (Ag) metal nanoparticle-based metamaterial structures were formed, and gold (Au) was changed according to the concentration of aqueous solution of HAuCl ₄ (0.014mM, 0.035mM) and reaction time (10, 30, 60 minutes). Galvanic substitution.

Example  3: based on metal nanoparticles Metamaterial  Structure

Prepared under the same conditions as in Example 2, except that the silver (Ag) metal nanoparticles were sintered, and the sintered silver (Ag) nanoparticle-based metamaterial structure was reacted at a concentration of 0.05 mM of HPtCl ₄ aqueous solution having an aqueous temperature of 80 degrees. Infiltrated in minutes, the silver (Ag) outer surface of the metamaterial structure was replaced with platinum (Pt).

<Evaluation of Example 1>

In Example 1, silver (Ag) nanoparticles were deposited on a substrate to form a metal thin film-based metamaterial structure, and according to the concentration of the aqueous HAuCl ₄ solution (0.007mM, 0.035mM) and the reaction time (10, 30, 60 minutes) The outer surface of silver (Ag) of the structure was galvanically substituted with gold (Au).

11 is a graph showing the change in the real part of the dielectric constant according to the galvanic substitution conditions (substitution solution concentration, reaction time) of Example 1. The abscissa and the ordinate represent the real part of the wavelength (nm) and the dielectric constant (ε), respectively. According to the concentration of aqueous solution of HAuCl ₄ (0.007mM, 0.035mM) and the reaction time (10, 30, 60 minutes), the degree of substitution of gold (Au) is ordered in order of 10 minutes, 30 minutes, 60 minutes at 0.007mM. Minutes and 0.035mM will be 10 minutes, 30 minutes and 60 minutes. On the graph, the real part of the dielectric constant is negative in the range of 400 nm to 1600 nm.

11, the amount of the galvanic substituted metal may be adjusted by adjusting the concentration and reaction time of the solution containing the metal to be substituted. In FIG. 11, as the atomic content of gold (Au) substituted according to the galvanic substitution increases, the real part of the permittivity has a negative permittivity characteristic that is close to zero. That is, it can be seen that the dielectric constant of the metamaterial structure of the present invention can be adjusted through galvanic substitution.

12 is a graph showing the imaginary part change in permittivity according to the galvanic substitution condition (substituent solution concentration, reaction time) of Example 1. FIG. The abscissa and the ordinate represent imaginary parts of wavelength (nm) and dielectric constant (ε), respectively. As described above in detail with reference to FIG. 11, when the gold (Au) substitution degree is arranged in order in order of 10 minutes, 30 minutes, 60 minutes at 0.07 mM and 10 minutes, 30 minutes, 60 minutes at 0.035 mM. In the graph, the imaginary part of dielectric constant varies linearly from about 1 to 2.5 to about 10 to 15 in the wavelength range of 400 nm to 1600 nm.

12, the amount of the galvanic substituted metal can be adjusted by adjusting the concentration and reaction time of the solution containing the metal to be substituted. In FIG. 12, the higher the atomic content of gold (Au) substituted according to the galvanic substitution, the lower the imaginary part of the dielectric constant. The higher the imaginary part of the dielectric constant, the greater the optical loss. Therefore, the higher the atomic content of gold (Au), the lower the imaginary part of the dielectric constant. That is, it can be seen that the dielectric constant of the metamaterial structure of the present invention can be adjusted through galvanic substitution.

In the metamaterial structure, the negative real part and the imaginary part of the dielectric constant mean plasmon resonance characteristics and optical loss (intrinsic electromagnetic energy loss due to the medium) of the metamaterial. 11 and 12, the higher the atomic content of gold (Au) substituted according to the galvanic substitution, the negative real part of the dielectric constant is closer to zero and the imaginary part is controlled lower.

< Example  2, Evaluation>

In Example 2, silver (Ag) nanoparticles were coated on a substrate to form a metal nanoparticle-based metamaterial structure, depending on the concentration of the aqueous solution of HAuCl ₄ (0.014mM, 0.035mM) and reaction time (10, 30, 60 minutes). The outer surface of silver (Ag) of the structure was galvanically substituted with gold (Au).

FIG. 13 is a graph showing changes in plasmonic resonance characteristics according to galvanic substitution conditions (replacement solution concentration and reaction time) of Example 2. FIG. The abscissa and the ordinate represent wavelengths (nm) and normalized transmittances, respectively. The normalized transmittance is 1.0 when the transmittance is 100%, and when transmittance is 0.0, the transmittance is 0%. For example, 0.6 transmittance means 60% transmittance. According to the concentration of the aqueous solution of HAuCl ₄ (0.014mM) and the reaction time (0, 10, 30, 60 minutes), the degree of gold (Au) substitution is ordered in the order of 0 minute, 10 minutes, 30 minutes at 0.014 mM. , 60 minutes. In the graph, the response time curve of 0 minutes (initial curve in FIG. 13) shows a resonance wavelength at about 750 nm, a 10 minute curve at about 850 nm, and a 30 minute curve at about 900 nm at 60 minutes. The curve of has a resonant wavelength at about 950 nm.

By interpreting FIG. 13, the amount of the galvanic substituted metal may be adjusted by adjusting the concentration and reaction time of the solution containing the metal to be substituted. In FIG. 13, as the atomic content of gold (Au) substituted according to the galvanic substitution increases, the resonance wavelength of the metamaterial structure shifts toward the longer wavelength. That is, it becomes a red shift. It can be seen that the plasmonic resonance characteristics of the metamaterial structure of the present invention can be adjusted through galvanic substitution.

FIG. 14 is a graph showing changes in plasmonic resonance characteristics according to galvanic substitution conditions (replacement solution concentration and reaction time) of Example 2. FIG. The horizontal and vertical axes represent wavelength (nm) and normalized transmittance, respectively. The normalized transmittance is 1.0 when the transmittance is 100%, and when transmittance is 0.0, the transmittance is 0%. For example, 0.6 transmittance means 60% transmittance. According to the concentration of the aqueous solution of HAuCl ₄ (0.035mM) and the reaction time (0, 10, 20 minutes), the substitution degree of gold (Au) is ordered in the order of 0 minute, 10 minutes, and 20 minutes at 0.035mM. On this graph, the curve of 0 minutes of response time (initial curve of FIG. 14) has a resonance wavelength at about 750 nm, a 10 minute curve at about 980 nm, and a 20 minute curve at about 1050 nm.

By analyzing FIG. 14, the amount of the galvanic substituted metal may be adjusted by adjusting the concentration and reaction time of the solution containing the metal to be substituted. In FIG. 14, as the atomic content of gold (Au) substituted according to the galvanic substitution increases, the resonance wavelength of the metamaterial structure moves toward the longer wavelength. That is, it becomes a red shift. It can be seen that the plasmonic resonance characteristics of the metamaterial structure of the present invention can be adjusted through galvanic substitution.

The normalized transmission at the resonant wavelength on Figs. 13, 14 has a value close to about 0.0. That is, as an example of the metamaterial structure of the present invention, the second embodiment has a characteristic of not selectively transmitting electromagnetic waves having a resonance wavelength. In Example 2, the resonant wavelength of the metamaterial structure shifts toward the longer wavelength as the atomic content of gold (Au) substituted according to the galvanic substitution increases. That is, the present invention has the advantage that the desired plasmonic resonance characteristics can be realized by simply adjusting the physical properties of the metamaterial structure through the galvanic substitution process.

The metamaterial structure in FIG. 15 was formed based on metal nanoparticles by coating silver (Ag) nanoparticles on a substrate according to the galvanic substitution condition of Example 2. The reaction concentration and reaction time were 0.035 mM in a HAuCl ₄ aqueous solution and a reaction time of 20 minutes, and the silver (Ag) outer surface of the metamaterial structure was galvanically substituted with gold (Au). 15 is a cross-sectional SEM, TEM image and EDX analysis results of the metamaterial structure prepared under the above conditions.

In the SEM image (left) in FIG. 15, the silver (Ag) outer surface of the metamaterial structure was replaced with gold (Au), and the EDX of the cross section of the metamaterial structure was confirmed through TEM (right). It can be seen that the structure is substituted with gold (Au) on the outer surface of silver (Ag). That is, the present invention can adjust the physical properties of the metamaterial structure using galvanic substitution.

<Evaluation of Example 3>

In Example 3, silver (Ag) nanoparticles were coated on a substrate to form a metal nanoparticle-based metamaterial structure, followed by sintering, and immersed in a concentration of 0.05 mM of HPtCl ₄ solution at a reaction time of 10 minutes for platinum (Pt). ) To replace the galvanic.

FIG. 16 is a graph illustrating changes in plasmonic resonance characteristics according to galvanic substitution of Example 3. FIG. The abscissa and the ordinate represent wavelengths (nm) and normalized transmittances, respectively. Meanwhile, sintered AgNPs in FIG. 16 mean sintered Silver NanoPartcles and are curves showing initial state resonance characteristics when the reaction time is 0 minutes. Ag-Pt in FIG. 16 is a curve showing resonance characteristics when the reaction time is 10 minutes. The normalized transmittance is 1.0 when the transmittance is 100%, and when transmittance is 0.0, the transmittance is 0%. For example, 0.6 transmittance means 60% transmittance. On this graph, the sintered AgNPs with a response time of 0 minutes have a resonance wavelength at about 780 nm, and the 10 minute curve (Ag-Pt) has a resonance wavelength at about 760 nm.

In FIG. 16, when the metal to be substituted is platinum (Pt), the resonance wavelength of the metamaterial structure is shifted toward the shorter wavelength. That is, it becomes blue-shift. In the case of galvanic substitution with gold (Au) in Example 2, it is interpreted that the resonant wavelength is opposite to the shift of the long wavelength (red displacement). That is, when galvanic substitution is performed by appropriately selecting and adjusting the metal to be substituted, it can be seen that the plasmonic resonance characteristics of the metamaterial structure of the present invention can be more precisely controlled.

The normalized transmission at the resonance wavelength on FIG. 16 has a value close to about 0.0. That is, Example 3 of the metamaterial structure of the present invention has a characteristic of not selectively transmitting electromagnetic waves of resonant wavelength. In Example 3, the resonant wavelength of the metamaterial structure shifts toward the shorter wavelength as the atomic content of platinum (Pt) substituted by galvanic substitution increases. That is, the present invention has the advantage that the desired plasmonic resonance characteristics can be realized by simply adjusting the physical properties of the metamaterial structure through the galvanic substitution process.

10: substrate
20 meta-structure
30: galvanic substituted metamaterial structure
40: substitution solution
200: metal thin film based metamaterial structure
300: galvanic substituted second metal
310: third metal double substituted by galvanic substitution
400: metal nanoparticle-based metamaterial structure
500: the first metal in the form of metal nanoparticles

Claims (17)

A first metal composed of a nanopattern;
A second metal galvanic substituted on the outer surface of the first metal;
Third to n-th metals galvanic substituted on the outer surfaces of the second to n-th metals; And
It includes; the coating layer consisting of the second metal to the n-th metal;
The first to n-th metals are each independently selected from the group consisting of silver (Ag), gold (Au), copper (Cu), aluminum (Al), nickel (Ni), chromium (Cr) or lead (Pb) A metamaterial structure comprising at least one metal:
(N is 4 or 5).
The method of claim 1,
The second metal has a reduction potential higher than that of the first metal, and the n-th metal has a reduction potential higher than that of the n-th metal.
The method of claim 2,
Meta-material structure, characterized in that the thickness of the coating layer is more than 1nm 200nm.
The method of claim 3,
A metamaterial structure, characterized in that the atomic content ratio of the second metal substituted with the first metal is 10: 1 or more and 10: 8 or less.
delete In the meta-material structure manufacturing method,
(First step) preparing a substrate;
(Second step) nanopatterning the first metal into a metal thin film on the substrate;
(Third step) immersing the substrate and the first metal in an aqueous solution containing the second metal;
(Step 4) forming a coating layer composed of a second metal by galvanic substitution of the outer surface of the first metal with the second metal; And
And an outer surface of each of the second metal to n-th metal to be galvanically substituted with the third metal to the n-th metal to form a coating layer composed of the third to n-th metals.
The first to n-th metals are each independently selected from the group consisting of silver (Ag), gold (Au), copper (Cu), aluminum (Al), nickel (Ni), chromium (Cr) or lead (Pb) One or more metals,
The nano-patterning is electron beam lithography, heated imprinting, UV imprinting, microcontact printing, microtransfer method, light stamp, capillary force lithography, capillary-micromolding, microtransfer molding, nanoimprinting, liquid-mediated transfer molding, chemical vapor Method for producing a metamaterial structure, characterized in that carried out by a method selected from the group consisting of vapor deposition, physical vapor deposition and combinations thereof:
(N is 4 or 5).
The method of claim 6,
Method for producing a meta-material structure, characterized in that the temperature of the aqueous solution containing the second metal is more than 60 ℃ 100 ℃.
The method of claim 7, wherein
Meta-material structure manufacturing method characterized in that the thickness of the coating layer is more than 1nm 200nm.
The method of claim 8,
Method for producing a meta-material structure, characterized in that the atomic content ratio of the first metal and the galvanic substituted second metal of the metal thin film is 10: 1 or more and 10: 8 or less.
delete In the meta-material structure manufacturing method,
(First step) preparing a substrate;
(Second step) nanopatterning the first metal on the substrate with at least one metal nanoparticle;
(Third step) immersing the substrate and the first metal in an aqueous solution containing the second metal;
(Step 4) forming a coating layer composed of a second metal by galvanic substitution of the outer surface of the first metal with the second metal; And
An outer surface of each of the second metal to n-th metal is galvanic substituted with a third to n-th metal to form a coating layer composed of third to n-th metals; Including;
The first to n-th metals are each independently selected from the group consisting of silver (Ag), gold (Au), copper (Cu), aluminum (Al), nickel (Ni), chromium (Cr) or lead (Pb) One or more metals,
The nano-patterning is electron beam lithography, heated imprinting, UV imprinting, microcontact printing, microtransfer method, light stamp, capillary force lithography, capillary-micromolding, microtransfer molding, nanoimprinting, liquid-mediated transfer molding, chemical vapor Method for producing a metamaterial structure, characterized in that carried out by a method selected from the group consisting of vapor deposition, physical vapor deposition and combinations thereof:
(N is 4 or 5).
The method of claim 11,
After the second step,
And thermally sintering the metal nanoparticles to couple between the metal nanoparticles.
delete The method of claim 12, wherein the temperature of the aqueous solution containing the second metal is 60 ° C. or more and 100 ° C. or less.
The method of claim 14,
Meta-material structure manufacturing method characterized in that the thickness of the coating layer is more than 1nm 200nm.
The method of claim 15,
Method for producing a meta-material structure, characterized in that the atomic content ratio of the first metal of the metal nanoparticles and the galvanic substituted second metal is 10: 1 or more and 10: 8 or less.
delete

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