KR20190084240A - Color Coating layer using metal nano structure and the method for manufacturing the same - Google Patents

Abstract

The present invention discloses an optical coating layer and a method for manufacturing the same, forming a plurality of metal nanostructures protruding or recessed below a visible light wavelength on a metal surface to realize vivid colors while maintaining unique metallic luster. The color coating layer comprises: a metal layer; and a plurality of metal nanostructures arranged on a surface of the metal layer.

Description

[0001] The present invention relates to a color coating layer using a metal nanostructure and a method for manufacturing the same,

The present invention relates to a color coating layer using a metal nanostructure and a method of manufacturing the same, and more particularly, to a method of manufacturing a color coating layer using a metal nanostructure by forming a protruding or depressed metal nanostructure array having a visible light wavelength or less on a metal surface, To a color coating layer and a manufacturing method thereof.

Conventionally, as a technique for realizing the surface color of an object, a coating material capable of realizing a desired color is coated on the surface, or a material such as an oxide is deposited in several layers to induce an effect by interference of light, Coating method, or simply coating a transition metal and a transition metal nitride-based material to achieve metal luster has been the mainstream.

However, the use of paints is advantageous to realize the specific color of paints, but it is difficult to realize high-quality luster such as metallic luster and is vulnerable to heat or ultraviolet ray. Transition metal and nitride coating techniques are limited by the color of the material itself There is a disadvantage that only color can be realized. In addition, although it is possible to realize various colors by selecting the structure and material of the multilayered film, it is necessary to control the thickness of the deposited multilayered film so that the color uniformity And reproducibility can be ensured. In particular, when it is applied to a three-dimensional structure such as a cellular phone, it is difficult to maintain uniformity of thickness, and it is difficult to maintain uniformity of color.

In order to solve these problems, researches have been carried out to form a nano structure on a metal surface to realize color. &Quot; METHOD AND DEVICE FOR CONTROLLING THE COLOR OF METALS "was published in U.S. Patent Application Publication No. 2012/0015118. This technique forms a nanostructure on a metal surface, and colors are displayed by using a characteristic light absorption phenomenon along a surface plasmon excitation.

However, even with this technology, various ranges of brightness, saturation and chromaticity can not be secured. Due to the limitations of materials, the structure is complicated and the process cost is increased. Thus, the color reproduction range can be expanded by simple structure and low cost process There is an urgent need for a metal color coating layer.

The present invention has been proposed in order to overcome the problems of the conventional color coating technique as described above, and it is intended to provide a metal surface nano structured coloring technology capable of realizing various high-definition colors while maintaining an aesthetic luster effect inherent in metal, and a manufacturing process thereof .

In order to accomplish the above object, the present invention provides a metal nano-nano-metal absorbing metal material, which has a nano-metal absorption metal material and has a protruding or depressed nanostructure pattern of a size smaller than the wavelength of visible light on its surface, A coloring technique and a manufacturing method thereof.

One aspect of the present invention provides a color coating layer having a metal layer and a plurality of metal nanostructures arranged on a surface of the metal layer, wherein the metal of the metal layer has a reflectance of 30% to 80% in a wavelength band of 300 nm to 800 nm.

Preferably, the metal of the metal layer is selected from the group consisting of Pd, Ni, Co, Fe, Mn, Cr, Mo, W, V, Ta, Nb, Hf, Zr, Ti, In, Sn, Pb, Sb, Bi, Can be selected.

The metal of the plurality of metal nanostructures may preferably have a reflectance of 30% to 80% in a wavelength band of 300 nm to 800 nm.

On the other hand, the plurality of metal nanostructures may be the same metal as the metal of the metal layer or another metal. The plurality of metal nanostructures are protruding or depressed.

It is also possible that the metal layer is coated on the base material or a buffer layer is further added between the metal layer and the plurality of metal nanostructures.

Another aspect of the present invention provides a method of manufacturing a semiconductor device comprising: a metallic ceramic layer; And a plurality of nanostructures arranged on a surface of the metallic ceramic layer, wherein the metallic ceramic has a reflectance of 30% to 80% in a wavelength band of 300 nm to 800 nm.

According to another aspect of the present invention, there is provided a method of fabricating a semiconductor device, comprising the steps of preparing a metal layer and forming a plurality of metal nanostructures arranged on the surface of the metal layer, wherein the metal has a reflectance of 30% To 80% by weight of the colored coating layer.

Preferably, the forming of the plurality of metal nanostructures may be performed by using an electroplating method, or alternatively, an imprint method may be used. When the electroplating method is used, there is an advantage that a simpler and less expensive process can be secured.

The metal surface nano coloring technique according to the present invention can realize various colors of high definition only by selecting the metal material and controlling the geometrical structure without a separate coloring layer while maintaining the luster of the metal, Process.

Further, the metal color coating technique according to the present invention can be applied not only to a metallic luster effect, but also to a color filter and a colorimetric sensor for a reflective display application.

1A and 1B are cross-sectional schematic views of a color coating layer according to an embodiment of the present invention.
2 is a schematic plan view of a color coating layer according to an embodiment of the present invention.
FIGS. 3A and 3B show results of light reflectance spectrum calculations when the Al metal surface is made into a protruding type (FIG. 3A) and a recessed (FIG. 3B) structure of a hexagonal lattice structure circular nano disk array.
Fig. 4 shows the reflectance spectra measured for the three primary colors of red, blue and green primary colors and the secondary color samples of cyan and magenta.
FIG. 5B is a graph showing the reflectance of a metal according to a wavelength. FIG. 5B is a graph showing the optical constants of a metal according to wavelengths, n (refractive index) and k (extinction coefficient) Fig.
6A is a graph of a light reflectance spectrum simulation result of a color coating layer in which a circular nano structure array is formed in a recessed structure so as to have a hexagonal lattice structure on a nickel (Ni) substrate according to an embodiment of the present invention. 6a is a graph showing the reflectivity curve when the depth of the Ni metal nanostructure hole is increased to 200 nm
FIG. 7 is a graph showing a change in reflectivity curve when Cr metal is used instead of Ni for the same structure as FIG. 6A. FIG.
8 is a simulation result of a reflectivity curve when a protruding nano disk array with a thickness of 100 nm is formed in hexagonal crystal lattice structure on the surface of a Ni substrate.
9 is a graph showing the effect of the duty cycle on the reflectance curve for a 50 nm thick Ni nanodisk array formed on a Ni substrate.
10A to 10C are flow charts illustrating a method according to an example of manufacturing a protruding color coating layer of the present invention.
11A to 11C are flow charts showing a method according to an example of manufacturing the depression type color coating layer of the present invention.
FIG. 12 is a diagram showing an L ^* C ^* h color space of brightness, chroma, and hue that can be implemented according to the present invention.
13 is a graph illustrating an example of a structure in which a metal layer is formed on a separate substrate and a nanostructure pattern is formed thereon, according to another embodiment of the present invention.
FIG. 14 is a view showing an example of fabricating the nanostructure pattern according to the present invention in an anisotropic shape in two dimensions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like or similar elements are denoted by like reference numerals and duplicate descriptions thereof will be omitted. The suffix "part" for the constituent elements used in the following description is to be given or mixed with consideration only for ease of specification, and does not have a meaning or role that distinguishes itself. In the following description of the embodiments of the present invention, a detailed description of related arts will be omitted when it is determined that the gist of the embodiments disclosed herein may be blurred. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. , ≪ / RTI > equivalents, and alternatives.

1A and 1B are cross-sectional schematic views of a color coating layer 1 according to an embodiment of the present invention.

The color coating layer 1 according to the present invention may include a metal layer 110 and a plurality of metal nanostructures 120 arranged at regular intervals in a protruding manner on the metal layer 110 as shown in FIG. And a plurality of metal nanostructures 130 whose surfaces are recessed. The plurality of metal nanostructures are formed with a period (P) and a size (d). The thickness of the protrusion and the depth of the recess are expressed as t.

The pattern size d of the metal nanostructures 120 and 130 may be 20 nm or more and less than 750 nm, and the period P may be 200 nm to 800 nm. The protruding height t may be 10 to 300 nm, and the recessed depth t may be 10 to 300 nm.

On the other hand, the shape of the protruding shape can be formed into various kinds of shapes such as a circle, a hexagon, a square, and a triangle without limitation, and the shape of the depressed shape can be various shapes such as circle, hexagon, .

Figure 2 shows the nanostructure geometry and geometry applicable to the surface nanostructure pattern of the color coating layer according to the present invention. Dimensional geometry such as a linear nanowire array and a two-dimensional lattice structure such as a square or hexagonal lattice. The shape of the nanostructure forming the lattice structure is applicable to various shapes including the quadrilateral and the circular structure.

According to the present invention, surface plasmon excitation occurs due to nanostructure patterns formed on the surface of a metal base material, and selective light absorption occurs strongly in a specific wavelength band by coupling with a lattice mode. This enables the color coating layer 1 to exhibit a beautiful color. More specifically, when light is incident, a surface plasmon wave is excited by nanostructure patterns formed on a metal surface. At this time, since the metal nanostructure patterns have a periodic lattice structure, they exhibit extraordinary optical absorption (EOA) in a specific wavelength band where coupling between lattice mode and surface plasmon mode occurs. The spectrum of specific light absorption varies depending on the geometrical factors of the lattice structure such as the kind of the metal and the surrounding material, the shape, size and period of the nanostructure, and the central wavelength is dominantly dependent on the period of the lattice .

In the present invention, the specific light absorption behavior that occurs in the periodic lattice-patterned nanostructured pattern formed on the metal surface is controlled effectively in terms of material and optical aspect, thereby changing the reflection spectrum from the metal surface, Surface nanostructured coloring technology.

First, a limited material such as a noble metal material with a small light absorption loss of the metal itself is used so that the surface plasmon resonance phenomenon may appear without loss in order to realize the color using the metal nanostructure. For example, metals selected from among Au, Ag, Cu, Al, and their alloys are predominantly used. Such a group of metals is generally known to be a metal having a relatively high reflectance and well excited by surface plasmons. However, in the present invention, it has been confirmed that it may be more effective to use a metal group that causes attenuation of surface plasmons, rather than metals to excite surface plasmons well. These metals generally have a relatively low reflectance of about 30% to 80%.

3A and 3B illustrate examples of the above-described case. In the case where the Al metal surface is made into a protruding type (FIG. 3A) and a recessed (FIG. 3B) structure of a circular nano disk array having a hexagonal lattice structure, The reflectivity spectrum calculation result is shown.

The thickness of protrusions and depressions was the same at 50 nm, and the period was varied from 400 nm to 700 nm at intervals of 100 nm. The duty cycle, which is the ratio of the diameter of the nanostructure to the period, is fixed at 50%. In both cases, the reflectivity is as high as 90% in the visible light wavelength range, and a sharp and deep reflection due to the specific light absorption phenomenon is formed. The reflectivity, or light absorption center wavelength, is red-shifted in proportion to the lattice period, thereby controlling the subtractive color. When the implemented color is expressed by the CIE L ^* C ^* h coordinate system defined by the International Lighting Commission, the projected structure is (94.4, 6.8, 110.1), (92.6 (95.9, 1.4, 118.9), (93.8, 20.1, 110.8), and (94.3) for the recessed structure, , 17.8, 327.4), (93.0, 9.2, 163.4).

CIE L ^* C ^* h The color coordinates represent the CIE L ^* a ^* b ^* coordinate system in polar coordinates. L ^* represents lightness, C ^* represents chroma, and h represents hue. The L ^* value has a number varying from 0 to 100, with 0 representing black and 100 representing full reflector. Therefore, in the case of the color coating layer of Al nanostructure, the brightness value is very high as 90 or more, while the saturation value is relatively low. In this case, the color expressed is not bright because of high brightness, and it has a pastel tone of light color.

The reflectance spectrum of the Macbeth ColorChecker standard color specimen was measured using a spectrophotometer equipped with an integrating sphere to refer to the vivid color reference. Fig. 4 shows the reflectance spectra measured for the three primary colors of red, blue and green primary colors and the secondary color samples of cyan and magenta. Compared with the reflectivity curves of FIGS. 3A and 3B, the significant difference is that the overall reflectivity is very low. It can be seen that the reflectivity of the center color peak is only about 30% to 40%.

Table 1

Table 1 summarizes the CIE L ^* a ^* b ^* color coordinate system provided for some standard color specimens including the color of FIG. 4 into the CIE L ^* C ^* h color coordinate system under the D ₆₅ light source (daylight) condition. It can be seen that the brightness value is formed low as a whole and the saturation value has a comparatively high value. The CIE L ^* C ^* h color space has a spherical shape with L ^* as the central axis. When L ^* is limited to a high value, the sharpness of color is inevitably low. It becomes extremely limited. As a result, it is necessary to lower the brightness value of the metal nanostructure color coating layer in order to achieve a clear color and broaden the color range.

For this purpose, the present invention employs a lossy metal having a relatively low reflectance as one of its characteristic features. In the present invention, a metal having a relatively low reflectance is used in a visible light region of 380 nm to 780 nm wavelength band with a reflectance of 30% to 80%. Therefore, it is preferable to use a metal selected from among Pd, Ni, Co, Fe, Mn, Cr, Mo, W, V, Ta, Nb, Hf, Zr, Ti, In, Sn, Pb, Sb, Bi, This is possible.

Even if an alloy containing a metal having a high reflectance is used, an alloy or metallic ceramic having a relatively low reflectance with a reflectance of about 30% to 80% in a wavelength band of 380 nm to 780 nm can be used in the present invention. Preferably, the metal nitride, carbide and / or nitride of Ti-N, Al-N, Cr-N, Zr-N, Ti-C, Cr-C, Fe-C, Mixing thereof or employing a compound may be effective. These metallic nitrides and carbides exhibit characteristic spectra according to their composition, unlike white metals exhibiting a constant reflectance spectrum in the entire visible light region, and thus have unique colors and metallic luster. In addition, it is possible to lower the reflectivity range to 30% according to the composition. Using these materials as the base material and nanostructuring the surface thereof, spectral distortion due to nano-structuring is added to the spectrum of the material itself, It is possible to obtain an effect of expanding the size of the display device.

On the other hand, in the case of metallic materials, there is not much material for lowering the reflectivity to 50% or less. In contrast, the use of metallic nitride, carbide, or a mixture or compound thereof can relatively easily lower the reflectivity to 50% There are advantages. That is, it is effective to apply an alloy type material such as a metal nitride or a carbide as a method for compensating for the lower limit of the reflectivity of the metal material. Thus, more preferably, the reflectivity of the above-mentioned metallic nitride, carbide and its mixture or compound may be 30% to 50%.

5A is a graph showing the reflectance of a metal with respect to a wavelength. Referring to FIG. 5A, the reflectance of metals such as Au, Ag, and Al, which is usefully used as a plasmonic matter, exceeds 80% in a wavelength band of 300 nm to 800 nm. As described above, the inventors of the present invention have found that it is difficult to realize a clear color in the case of using a metal having a high reflectivity and an excellent plasmonic resonance characteristic, and it is difficult to manufacture the metal having a high value in the drawing.

Meanwhile, FIG. 5B is a graph showing the optical constants of the metal according to the wavelength, the value of n (refractive index) and k (extinction coefficient) on the ordinate axis corresponding to the k value when the horizontal axis is n. The optical constant value is shown taking a value from 300 nm to 800 nm in the wavelength range. Referring to FIG. 3B, it can be seen that the dispersion behavior of n and k values of the metal material is largely divided into two regions. The material group adjacent to the longitudinal axis, such as Al, Ag, and Au, is a typical plasmonic material. Since the n value is very small and the k value has a dispersion behavior that increases in proportion to the wavelength, the absorption loss of the material itself is low. On the other hand, in the graphs of the horizontal axis n and the vertical axis k, the metals present in the intermediate region have a large absorption loss of the material itself and a relatively low reflectivity because the imaginary term of the dielectric constant defined by 2nk is large. Referring to FIG. 5A, it can be seen that the material group corresponds to a metal exhibiting a relatively low reflectance of about 30% to 80% in a wavelength band of 300 nm to 800 nm.

FIG. 6A is a graph of a light reflectance spectrum simulation result for a color coating layer in which a circular nano structure array is formed in a recessed structure so as to have a hexagonal lattice structure on a nickel (Ni) substrate according to an embodiment of the present invention. The depth of the depression was fixed at 100 nm and the duty cycle was fixed at 50%. The result was calculated by changing the period from 400 nm to 600 nm at intervals of 100 nm. Compared to the Al substrate case of FIG. 3, the lattice period dependence is still evident, but a significant decrease in the basic reflectivity and reflectivity? The widening of the curve can be confirmed. In the case of the periodic lattice structure nanostructure pattern formed on the metal base material, the reinforced light absorbing substrate through the coupling with the lattice mode operates in spite of the surface plasmon attenuation due to the combination of the optical constants of the metal itself, .

FIG CIE L ^* C ^* h ask a coordinate value, period 400 nm, 500 nm, 600 nm for each (72.4, 31.9, 89.6), (72.7, 29.2, 6.7), (62.1, 18.8 from the reflectivity curves of 6a, 269.6). Compared with the Al substrate, the brightness value is significantly lowered, and the saturation value is also increased to 31.9.

6B shows the reflectivity curve when the depth of the Ni metal nano-structure hole is increased to 200 nm in the structure of FIG. 6A. Compared to FIG. 6A, the reflectivity? It can be seen that the center wavelength of the curve moves to the long wavelength region and the half price width increases. The L ^* C ^* h coordinate values are (68.8, 36.9, 82.9), (61.7, 38.4, 341.0), (55.9, 36.9, 212.9) for the periods 400 nm, 500 nm and 600 nm, respectively. As the height of the depressed metal nanostructure pattern increases, the brightness value of the implemented color is further reduced, and the saturation value is greatly increased.

FIG. 7 shows a change in reflectivity curve when Cr metal is used instead of Ni for the same structure as FIG. 6A. The overall tendency is similar, but it can be seen that the basic reflectivity curve does not lean to the short wavelength region unlike the Ni, but has a flat curve distribution according to the reflectivity spectrum characteristics of the metal itself. The CIE L ^* C ^* h coordinate values have values of (77.4, 13.6, 110.4), (74.6, 17.9, 67.0), (69.9, 35.3, 299.9) for the periods of 400 nm, 500 nm and 600 nm, respectively.

8 shows a simulation result of a reflectance curve when a protruding nano disk array of 100 nm thickness is formed on a surface of a Ni substrate in a hexagonal lattice structure. 6A, the total reflectance is significantly lowered to 50% or less, and the half-value width is greatly widened. (40.2, 41.0, 57.9), (40.4, 65.3, 315.5), (43.3, 48.5, and 234.0) for the periods of 400 nm, 500 nm and 600 nm in the CIE L ^* C ^* h coordinate system. The brightness decreased significantly to about 40, and the saturation value increased to a maximum of 65.3.

9 is a graph showing the effect of the duty cycle on the reflectance curve for a 50 nm thick Ni nanodisk array formed on a Ni substrate. For a hexagonal lattice period of 400 nm, increasing the diameter of the nanodisk by 50 nm from 200 nm to 250 nm indicates that the red shift of the center wavelength of light absorption and the half-width increase of the light absorption curve are observed. The CIE L ^* C ^* h coordinate values were changed from (70.9, 32.6, 86.2) to (65.2, 40.5, 77.42).

Referring to the case where the period of FIG. 9 is 200 nm, it can be seen that the shape of the reflectivity curve can be gradually increased only in one direction of the wavelength. Also in this case, as the diameter of the nanodisk is increased from 100 nm to 150 nm, the reflectivity boundary wavelength shifts to a long wavelength. The L ^* C ^* h coordinate system changed from (70.1, 23.9, 84.1) to (57.9, 49.3, 44.2). In particular, it can be seen that the reflectivity remains low throughout the short wavelength range, which suggests that a spectrum similar to red or yellow standard specimen reflectance curves may be implemented, depending on the structural and material design.

 The pattern size of the metal nanostructures 120 can be 20 nm or more and less than 750 nm, and the period is preferably 200 nm to 800 nm. In the case of manufacturing a pattern with a size of 200 nm or more, a photolithography process can be used instead of expensive processes such as beam lithography, and a metal nano structure coating layer can be formed in a large area by an inexpensive process such as electroplating and imprinting after master mold replication It is possible to produce.

The protrusion height of the protrusion can be made 10 to 300 nm, and the depth of recess can be made 10 to 300 nm.

On the other hand, the shape of the protruding shape can be formed into various kinds of shapes such as a circle, a hexagon, a square, and a triangle without limitation, and the shape of the depressed shape can be various shapes such as circle, hexagon, ≪ / RTI >

10A to 10C are flow charts illustrating a method according to an example of manufacturing a protruding color coating layer of the present invention.

Referring to FIG. 10A, a metal layer 110 is first prepared. The metal layer 110 may be a metal surface of an object or may be formed of a metal layer separately. For example, when a color coating layer of the present invention is to be formed on the back side of a mobile phone, a metal or alloy layer having a relatively low reflectivity can be formed with a reflectance of 30% to 80% in a wavelength band of 300 nm to 800 nm as described above It can be regarded as a metal layer 110. In the case where the back surface of the mobile phone is made of a metal or alloy layer having a relatively low reflectance of about 30% to 80% in a wavelength band of 300 nm to 800 nm, it is also possible to designate the surface thereof as the metal layer 110.

Next, referring to FIG. 10B, the protruding metal nanostructure 120 is formed using a plating mold. The protruding metal nanostructure 120 may be the same metal as the metal layer 110 or may be another metal. However, it may be more effective for the purpose of realizing the object of the present invention that the protruding type metal nanostructure 120 is made of a metal or alloy layer having a relatively low reflectance of about 30% to 80% in a wavelength band of 300 nm to 800 nm .

Referring to FIG. 10C, the plating mask is removed to complete the manufacture of the color coating layer.

11A to 11C are flow charts showing a method according to an example of manufacturing the depression type color coating layer of the present invention.

On the other hand, in FIGS. 10A to 10C and 11A to 11C, a method of manufacturing a color coating layer by electroplating has been described, but the production of the color coating layer is not limited thereto. Alternatively, the nanoimprint method can be used. According to this method, a metal nanostructure or a depressed metal nano structure is imprinted on the metal layer.

12 is a diagram showing L ^* C ^* h color space of lightness, saturation, and color. Referring to FIG. 12, it can be seen that as the brightness increases, the saturation value has a relatively small range of values. The present inventors have found that when the color coating layer of the present invention is fabricated of a metal or alloy layer having a relatively low reflectance of 30% to 80% in a wavelength band of 300 nm to 800 nm, a suitable brightness is ensured, Color coating layer can be realized.

The color realized in the conventional high reflectivity metal is in a high brightness area having an L ^* value of 80 or more, so that the sharpness of the color is degraded and there is a clear limit to the range of color realization as can be seen from the volume occupied in the L ^* C ^* h color space . According to the present invention, it is possible to manufacture a color coating layer capable of remarkably expanding the color realization range as well as the color sharpness by largely expanding the brightness control range to 30 L ^* 80 by controlling the metal having a low reflectance and the geometry have.

In addition, metals such as Ni and Cr are very advantageous for producing metal products having a nanostructure surface at low cost by using electrolytic processes. It is also possible to use an alloy with Cu, Sn, Zn or the like to reduce the allergen inducing effect.

13 is a graph showing an example of a structure in which a metal layer 110 is formed on a base material 100 such as a separate substrate and metal nanostructure patterns 120 and 130 are formed thereon. It is also possible to insert a separate buffer layer (not shown) between the metal layer 110 and the metal nanostructure patterns 120 and 130. The buffer layer is preferably a metal and is preferably a metal selected from the group consisting of Pd, Ni, Co, Fe, Mn, Cr, Mo, W, V, Ta, Nb, Hf, Zr, Ti, In, Sn, Pb, Sb, Bi, It is possible to adopt a selected metal.

Also, as illustrated in FIG. 14, the nanostructure pattern according to the present invention can be formed in an anisotropic shape in a two-dimensional manner. In this case, different colors may be implemented depending on the viewing direction.

It is also possible to alternately arrange two or more patterns having different periods for a mixed color effect. By doing so, it is possible to realize a green-based color and an orange-based color having reflectance peaks in the middle region in the visible light region.

Meanwhile, the metal nanostructure color coating layer technique according to the present invention can be applied to a technique of a paint such as a metal effect pigment by being manufactured in a metal flake form.

The color coating layer described above is not limited to the configuration and the method of the embodiments described above, but the embodiments may be configured by selectively combining all or a part of each embodiment so that various modifications can be made. It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the above description should not be construed in a limiting sense in all respects and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention.

Claims (18)

A metal layer; And
A plurality of metal nanostructures arranged on a surface of the metal layer,
Wherein the metal of the metal layer has a reflectance of 30% to 80% in a wavelength band of 300 nm to 800 nm.
The method according to claim 1,
The metal of the metal layer is at least one selected from Pd, Ni, Co, Fe, Mn, Cr, Mo, W, V, Ta, Nb, Hf, Zr, Ti, In, Sn, Pb, Sb, Bi, Lt; / RTI >
The method according to claim 1,
Wherein the metal of the plurality of metal nanostructures has a reflectance of 30% to 80% in a wavelength band of 300 nm to 800 nm.
The method according to claim 1,
Wherein the plurality of metal nanostructures are the same metal as or different from the metal of the metal layer.
The method according to claim 1,
Wherein the plurality of metal nanostructures are protruding or depressed.
The method according to claim 1,
Wherein the metal layer is coated on the base material.
The method according to claim 1,
Wherein a buffer layer is further added between the metal layer and the plurality of metal nanostructures.
A metallic ceramic layer; And
And a plurality of nanostructures arranged on a surface of the metallic ceramic layer,
Wherein the metallic ceramic has a reflectance of 30% to 80% in a wavelength band of 300 nm to 800 nm.
9. The method of claim 8,
Wherein the metallic ceramic is a metallic nitride, a carbide, and a mixture or compound thereof.
10. The method of claim 9,
Wherein the metallic ceramic is at least one selected from Ti-N, Al-N, Cr-N, Zr-N, Ti-C, Cr-C, Fe-C, Co-C, Ni-C, Zr- Lt; / RTI >
Preparing a metal layer; And
And forming a plurality of metal nanostructures arranged on a surface of the metal layer,
Wherein the metal of the metal layer has a reflectance of 30% to 80% in a wavelength band of 300 nm to 800 nm.
12. The method of claim 11,
Wherein the forming of the plurality of metal nanostructures is performed by an electroplating method.
12. The method of claim 11,
Wherein the forming of the plurality of metal nanostructures is performed by using an imprint method.
12. The method of claim 11,
The metal of the metal layer is at least one selected from Pd, Ni, Co, Fe, Mn, Cr, Mo, W, V, Ta, Nb, Hf, Zr, Ti, In, Sn, Pb, Sb, Bi, ≪ / RTI >
12. The method of claim 11,
Wherein the metal of the plurality of metal nanostructures has a reflectance of 30% to 80% in a wavelength band of 300 nm to 800 nm.
12. The method of claim 11,
Wherein the plurality of metal nanostructures are the same metal as or different from the metal of the metal layer.
12. The method of claim 11,
Wherein the plurality of metal nanostructures are protruding or depressed.
12. The method of claim 11,
Wherein the metal layer is coated on the base material.

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