KR100406442B1 - Wave-length selective multi-layered transparent conducting thin films - Google Patents

Abstract

The present invention is a thin film of a multi-layered structure formed by alternately forming two or more layers of a transparent film and a metal film on a substrate, the transparent film is a thin film formed using a material capable of transmitting light in the visible light region, the metal film of each layer Provided is a transparent conductive film having a wavelength selective multilayer structure having a thickness in the range of 5 to 50 nm. By controlling the number of alternating times or the thickness of each layer of the transparent film and the metal film forming the multi-layer structure, it is possible to adjust the light transmittance in the wavelength range of the desired light, to be used in a filter for shielding the transparent electrodes or electromagnetic waves used in flat panel displays Can be.

Description

Transparent conductive film with wavelength-selective multilayer structure {WAVE-LENGTH SELECTIVE MULTI-LAYERED TRANSPARENT CONDUCTING THIN FILMS}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent conductive film having a multi-layered structure that can control light transmittance in a selected wavelength range and has excellent conductivity, including TFT-LCD (Thin film transister liquid crystal display), PDP (Plasma panel display), and FED (Field emission). Shielding electromagnetic waves like transparent electrodes or PDPs or FEDs that transmit visible light that is used in flat panel displays such as displays), electroluminescent displays (ELD), organic electroluminescent displays (OELD), and solar cells using photoelectric effects. Can be used as a filter.

In general, an oxide-based material having a doping element added to SnO ₂ , In ₂ O ₃ , ZnO, or the like has been used as a transparent conductive film material that transmits light and is electrically conductive. Research on oxide-based transparent conductive films has not been commercially available since the first report showing that a transparent electrical conductive film can be obtained by oxidizing a Cd metal film deposited in a glow discharge chamber in 1907. It has emerged. However, full-scale R & D and commercialization of transparent conductive film materials began in the 1960s, and SnO _2- based transparent conductive films were developed by pyrolysis spray or sputtering, and thus, for building window glass or solar cell electrodes for energy saving. It has been applied to the material, and has established itself as an In ₂ O ₃ based (ITO) transparent conductive film added with Sn by sol-gel, evaporation or sputtering. On the other hand, research on ZnO-based oxide film, which has been widely studied as a sensor material, has been actively conducted since the 1980s, and the development of a transparent conductive film material by addition of Al, Ga, F or rare earth elements to ZnO Some studies have begun to show a degree of performance and are now achieving resistivity comparable to that of ITO.

In the practical application of the transparent conductive film, an important electrical resistance property is expressed as sheet resistance, which is obtained by dividing the specific resistance value by the thickness of the film actually used. For example, when a transparent conductive film having a specific resistance of 1 × 10 ⁻⁴ dBm is used at a thickness of 100 nm, the sheet resistance is 10 μs / Is given by.

In recent years, with the trend toward larger area and higher resolution of flat panel displays, stricter regulations for shielding electromagnetic waves, and new displays using organic EL, surface transmittance is maintained at 10 Ω / The demand for smaller conductive properties has increased the need for a more improved transparent conductive film. In addition, displays such as PDPs require a filter for blocking electromagnetic waves due to their characteristics. To be used as an effective electromagnetic wave blocking filter, the transmittance must be good as well as 1Ω / It is known that the following resistance is required.

However, until now, stability and reproducibility, and the highest electrical conductivity and light transmittance, ITO is the most widely used material for high quality flat panel display electrode film or electromagnetic wave shielding material, but for the last 20 years, Despite many efforts to improve the conductivity, no further progress has been made in terms of electrical conductivity because the resistivity value is limited to 1 × 2 × 10 ⁻⁴ dBm. Therefore, sheet resistance 10Ω / In order to obtain the following conductive properties, the thickness of the transparent conductive film must be thick, and this increase in thickness again causes a decrease in the light transmittance, thereby reducing the function as the transparent conductive film.

As described above, an oxide-based transparent conductive film such as ITO usually has a specific resistance value of about 1 to 10 × 10 ⁻⁴ μm cm, and usually has a specific resistance of about 1 to 5 × 10 ⁻⁶ μm cm, aluminum, gold, It has an inferior conductivity of about 1/100 or less as compared to metal films such as silver, copper, or alloys thereof.

Although the metal film is excellent in electrical conductivity, as in the case of the Ag thin film shown in FIG. 1, the light transmittance is low and the thickness is 5 nm or less to maintain a certain degree of permeability in the visible light region. The function as a transparent conductive film is lost.

When the metal thin film is deposited in vacuum, the metal film is formed to form a continuous thin film by forming islands and then forming islands as the islands continue to grow, and are grown by general vacuum deposition or magnetron sputtering. Ag thin film is known to form a continuous thin film to be more than 10nm thickness. As shown in FIG. 1, the metal thin film having such a thickness has low permeability and cannot be used as a transparent conductive film by itself.

In addition, recently, a transparent conductive film in which a metal film such as Ag is sandwiched between oxide-based transparent conductive films has been released. , When Ag is formed at 30 nm, 1 Ω / A degree of improvement has been reported. However, when Ag is formed at 10 nm, light transmittance is high only around the wavelength of 500 to 600 nm, but light transmittance is remarkably decreased in the wavelength range of 400 nm, which is a blue region.

Recently, display devices using organic ELs, which are emerging as one of new flat panel displays, are increasingly using plastic substrates that are not only impact-resistant and light, but also easily bent. However, in the case of an oxide-based transparent conductive film containing ITO, which is currently used most often as a transparent conductive film, in order to obtain a value of resistivity of 5 × 10 ^-4 Ωcm or less, a deposition temperature is generally set to 300 ° C. or higher or a film synthesized at room temperature. Heat treatment should be performed at a temperature above 200 ℃. This is to promote the crystal growth of the oxide-based thin film to increase the mobility of electrons to increase the conductivity. The oxide-based transparent conductive film synthesized at a low temperature is formed in an amorphous state or in a fine grain structure, resulting in a decrease in electron mobility and consequently decrease in conductivity, thus having a resistivity of about 10 ^-3 Ωcm. Therefore, it is very difficult to implement a high quality oxide transparent conductive film on a substrate that cannot be processed at a high temperature, such as plastic, and thus the application range of the high quality oxide transparent conductive film is limited. Such a plastic substrate not only needs a low temperature process, but also has a property of permeating oxygen or water in the air, which deteriorates the luminescence properties of the organic material used as the light emitting material, so that environmental resistance is strongly required.

Accordingly, the present invention has been made in view of the problems of the prior art, and an object thereof is to provide a transparent conductive film having improved electrical characteristics while maintaining a high light transmittance.

In addition, an object of the present invention has a high electrical conductivity and can arbitrarily adjust the light transmittance in the desired wavelength range, can not only function as a transparent conductive film for a simple electrode, but also have the function of an optical filter at the same time, a function for blocking electromagnetic waves The present invention also provides a transparent conductive film.

Another object of the present invention is to provide a high-quality transparent conductive film that can be synthesized even at low temperatures.

1 is a graph showing the change in light transmittance according to the thickness change of the Ag thin film.

2 is a schematic cross-sectional view of a multilayer structure transparent conductive film provided by the present invention.

Figure 3 is a graph showing the visible light transmittance of the multilayer structure transparent conductive film provided by the present invention.

4 is a graph showing the visible light transmittance and the near-ultraviolet and near-infrared blocking ability of the multilayer structure transparent conductive film provided by the present invention.

5 is a graph showing the transmission of red light by the multilayer structure transparent conductive film provided by the present invention.

Figure 6 is a graph showing the green light transmission by the multilayer structure transparent conductive film provided by the present invention.

7 is a graph showing blue light transmission by the multilayer structure transparent conductive film provided by the present invention.

8 is a graph showing green light transmission by a multilayer structure transparent conductive film in which a metal film provided in the present invention is a top layer.

*** Explanation of symbols for the main parts of the drawing ***

1: light 2: substrate

3a: transparent film 3b: transparent film

3c: transparent film 3d: transparent film

4a: metal film 4b: metal film

4c: metal film

In order to achieve the above object, the present invention is a thin film of a multi-layer structure formed by alternately forming two or more layers of a transparent film and a metal film on a substrate, the transparent film is a thin film formed using a material that can transmit light in the visible light region The metal film provides a wavelength selective transparent conductive film, wherein each layer has a thickness in a range of 5 to 50 nm.

By controlling the number of alternating times or the thickness of each layer of the transparent film and the metal film forming the multi-layer structure, the transmittance of light can be controlled in the wavelength range of the desired light, the transparent film and the metal film layer forming the multi-layer structure, respectively two layers Alternately, the numbers of the transparent film layers and the metal film layers may be the same or different.

When the thickness of the metal film is 5 nm or less, the film formation itself is very difficult, and when it exceeds 50 nm, the transmittance is very low and it is difficult to be used in a transparent conductive film. As the substrate material on which the multilayer structure is formed, glass or plastic that transmits light is suitable.

2 shows a typical example of a multilayer structure which is a transparent conductive film provided by the present invention. Transparent film 3a, metal film 4a, transparent film 3b, metal film 4b, transparent film 3c, metal film 4c, transparent on substrate 2 through which light 1 is transmitted The film 3d shows an alternately deposited structure.

Such a transparent conductive film having a multilayer structure is not limited to the structure shown in FIG. 2 and can be changed depending on the purpose. That is, a metal film is first deposited on the substrate, and a structure consisting of a transparent film, a metal film, a transparent film, a metal film, and a transparent film or a final layer deposited may be a metal film. In addition, the alternating period of the transparent film and the metal film is not limited to the three periods shown in FIG. 2, but any period of two or more periods is possible. In addition, although the light 1 is shown in a manner of traveling toward the substrate 2 through the multilayer structure in FIG. 2, a method in which light 1 enters the substrate 2 portion and passes through the multilayer structure is also possible. Do.

The transparent film forming the multilayer structure may be selected from a dielectric material having a property of transmitting light in the visible light region, an oxide material having light transmitting in the visible light region and an electrically conductive material, or a polymer material transmitting light in the visible light region.

The dielectric material forming the multilayer structure may be SiO ₂ , TiO ₂ , ZrO ₂ , HfO ₂ , Al ₂ O ₃ , ZnO, Y ₂ O ₃ , BeO, MgO, PbO ₂ , WO ₃ , VO _X , SiN _{X , GeN X, AlN, ZnS,} CdS, SiC, MgF, CaF 2, NaF, BaF 2, PbF 2, LiF, LaF 3, can be used in any one or more than two mixing compound two selected from the group consisting of GaP Do.

Examples of the electrically conductive oxide material forming the multilayer structure include Sn-added In ₂ O ₃ , F, or Sb-added SnO ₂ , Al, Ga, B, Y, In, Sc, Si, Ge, Ti, Zr, Hf. Oxides added with impurities such as ZnO, In, or CdO added with one or two or more of N, F, or Cd0, MgO, SnO ₂ , In ₂ O ₃ , ZnO, GaO, PbO ₂ , Tl ₂ O ₃ , It is possible to use mixtures of oxides such as Sb ₂ O ₅ and oxides with impurities added to these mixtures. In addition, an oxide having a structure of AMO ₂ may be used, where A is a monovalent (+1) (monovalent) metal such as Cu, Ag, Li, Na, K, and M is Al, Ga, In, Tl, Sc, It is an oxide composed of trivalent (+3) (trivalent) metals such as Y and La, and a small amount of impurity is added thereto or a structure substituted by impurities may be used.

The polymer material forming the multilayer structure may include polycarbonate, polymethyl meta acrylate, polystyrene, polyester, polyethylene terephthalate, and acryl. Use of a material selected from the group consisting of resins is possible.

As the metal film material forming the multilayer structure, Ag, Au, Cu, Pd, Pt, Ni, Al, Y, La, Mg, Ca, Li, K, Na, Cr, Mo, W, V, Ta, Co, Fe, Nb, Mn, Re, In, Sn, Zn, Pb or their alloys can be selected.

In general, when the metal has a small refractive index n and a large light attenuation coefficient k, and thus forms a single layer, the metal has high reflectivity and hardly transmits. As shown in FIG. 1, even though the thickness of Ag is about 10 nm, the transmittance in the visible light region drops to 60% and rapidly decreases to 20% in 20nm. However, when such a metal film is combined with a material that transmits visible light to form a multi-layer structure as provided by the present invention, the propagation property of light in a multi-layered medium is changed by a phenomenon called resonant tunneling.

That is, in the multi-layered medium in which the transparent film and the metal film are periodically arranged as provided in the present invention, a group velocity of light, which is one of electromagnetic waves, is caused by a sudden change in refractive index at adjacent transparent film / metal film interfaces. The velocity changes and the absorption of light traveling through the metal film with a large attenuation factor is drastically reduced, resulting in a change in transparency and reflectivity. The wavelength of the resonance tunneling and the degree of resonance tunneling vary depending on the optical properties of the transparent film and the metal film of the multilayer structure, the thickness of the individual film, the number of cycles and the order of formation of the multilayer structure. When properly combined, the transmittance in the wavelength region of the desired light can be adjusted.

As described above, in the multilayer structure of the transparent film and the metal film provided in the present invention, the transmittance in each wavelength band of light can be adjusted, and since the metal film having excellent electrical conductivity is included in the multilayer structure, the electrical conductivity is applied to the metal film. It is possible to improve to a comparable level. In addition, at least one of the transparent films used in the multilayer structure is electrically conductive, and when the transparent oxide-based transparent conductive film is used, it may have better electrical conductivity by combining the metal film and the oxide-based transparent conductive film.

Such a transparent conductive film can be used as a good electromagnetic wave shielding material as described below, and furthermore, in the multilayer structure as shown in FIG. If an existing oxide-based transparent conductive film is used, it can be applied as a transparent conductive film for electrodes of flat panel displays.

One of the advantages of the multilayer structure transparent conductive film provided by the present invention is that a transparent conductive film having excellent light transmittance and electrical conductivity can be synthesized at a low temperature. As described above, in order to obtain a high-quality transparent conductive film having a specific resistance of 5 × 10 ⁻⁴ Ωcm or less in an oxide-based transparent conductive film including ITO, which is currently used as a transparent conductive film, a high temperature process of 200 ° C. or higher is essential. to be. Therefore, it is not applicable to plastic substrates that easily deform at temperatures above 100 ° C. such as polycarbonate, acrylic, and PET. However, the transparent conductive film of the multilayer structure including the metal film provided by the present invention can be synthesized at low temperature at room temperature of 100 ° C or lower. This is because the electrical conductivity is excellent due to the adjacent metal film even when the oxide-based transparent film is to be used as one component layer. In addition, in the case of applying the multilayer structure provided by the present invention, when one or two layers of the transparent film layer of FIG. 2 are used as a dielectric material forming a dense film such as Si ₃ N ₄ , AlN, Al ₂ O _3, etc. Oxygen or water in the air can be prevented from penetrating into the organic material formed on the multi-layered transparent conductive film, and the environmental resistance when using the plastic substrate can be increased.

On the other hand, the transparent conductive film of the multilayer structure according to the present invention can be produced by any existing thin film forming method such as sputtering, CVD, PVD and the like.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings in which preferred embodiments are shown, but the present invention is not intended to be limited thereto.

Example 1

3 shows the transmittance in the visible light region of the transparent conductive film having a multilayer structure in which the transparent film / metal film provided by the present invention is alternately shown. In the multilayer structure of FIG. 3, six layers of a dielectric film (Si ₃ N ₄ ) and a metal film (Ag) are alternately formed on a glass substrate, and finally, an oxide-based transparent conductive film (ITO is used in this embodiment). In this coated structure, the thickness of each layer was 45 nm, 80 nm, and 70 nm in order from ITO to 30 nm, Ag to 10 nm, and Si ₃ N ₄ in order from the substrate as shown in FIG.

As shown in FIG. 3, the transparent conductive film of the multilayer structure provided by the present invention has a total thickness of 30 nm of Ag film forming a multilayer structure, but shows a transmittance of 80% or more in the wavelength range of 440 to 700 nm, which is a visible light region, and a maximum of 90%. It can be seen that the wavelength reaching the transmittance can also be obtained. The multi-layer structure of this embodiment is made of ITO, which is an oxide-based transparent conductive film material, and has excellent conductivity by being combined with a lower Ag film. Therefore, the multi-layered transparent conductive film provided by the present invention can be used as an electrode material for which a transparent material is required while excellent in conductivity in flat panel displays such as TFT-LCD, PDP, FED, ELD, OELD, and the like.

Example 2

4 is made of the same structure and material as in FIG. 3, but shows the transmittance of the multilayered structure in which the thickness of each layer is changed. The thickness of each layer was 160 nm in ITO, Ag was 10 nm, 15 nm, and 10 nm in order from the substrate, and Si ₃ N ₄ was 65 nm, 85 nm and 80 nm in order from the substrate, as shown in the figure. Unlike the multilayer structure shown in FIG. 3 showing even transmittance in the visible light region, the transmittance of the multilayer structure shown in FIG. 4 has a transmittance peak around 650 nm, 530 nm, and 440 nm in the red, green, and blue wavelength ranges. Seems. In addition, the multilayer structure shown in FIG. 4 exhibits a rapid decrease in transmittance in the near-ultraviolet region with a wavelength of 400 nm and a sharp decrease in transmittance even in the near-infrared region of 750 nm or more.

By using the features shown in FIG. 4 obtained through the proper design of the multilayer structure, it can be seen that it can also be used as a filter material for the PDP. That is, in the case of PDP, electromagnetic waves are emitted due to the characteristics of plasma discharge, so an electromagnetic shielding filter should be used to prevent malfunction of surrounding electronic devices. In addition, the wavelength of the near-infrared region emitted from the PDP is the same as that used in the remote controller of general home appliances, and if it is not blocked, the remote controller of the peripheral device cannot be used and the 400nm wavelength is harmful to the human body. have. For this reason, it is essential to adopt a filter suitable for the above purpose in a PDP that is spotlighted as a large wall-mounted TV.

In addition, in recent years, displays such as FEDs have also increased in acceleration voltage, and thus, it is necessary to adopt an electromagnetic shielding filter such as a PDP. As shown in FIG. 4, the transparent conductive film of the multilayer structure provided by the present invention contains a metal film and an oxide-based transparent conductive film, thereby providing a function of blocking electromagnetic waves, as well as blocking the near infrared region in the wavelength range of 750 to 1100 nm. It can be seen that it can be used as a filter material that satisfies the near-ultraviolet region blocking ability in the region of 400 nm and also has excellent transmittance of visible light. Furthermore, when the transparent conductive film of the present invention is used as a bus electrode of the front panel of a display such as PDP or FED, it can function not only as a transparent electrode film material but also as a filter. You can get the result.

Example 3

FIG. 5 shows the transmittance for each wavelength of the transparent conductive film having the multilayer structure or the thickness of each layer having the structure as shown in Example 1. FIG. As shown in the figure, the thickness of each layer was 100 nm in ITO, Ag was 17 nm, 43 nm and 17 nm in order from the substrate, and Si ₃ N ₄ was 100 nm, 115 nm and 115 nm in order from the substrate. The multi-layered structure of this embodiment shows a peak in transmittance near 650 nm, which is a red wavelength region, and unlike the previous embodiment, it can be seen that there is little transmittance in other wavelength bands.

Example 4

FIG. 6 shows the transmittance for each wavelength of the transparent conductive film having the multilayer structure or the thickness of each layer having the structure as shown in Example 1. FIG. The thickness of each layer was 90 nm in ITO, Ag was 15 nm, 37 nm and 15 nm in order from the substrate, and Si ₃ N ₄ was 70 nm, 85 nm and 85 nm in order from the substrate, as shown in the figure. It can be seen that the multilayer structure of this embodiment shows a peak of transmittance in the vicinity of 530 nm, which is the green wavelength region, and almost no transmittance in other wavelength bands.

Example 5

FIG. 7 shows the transmittance for each wavelength of the transparent conductive film having the multilayer structure or the thickness of each layer having the structure as shown in Example 1. FIG. The thickness of each layer was 81 nm in ITO, Ag was 15 nm, 36 nm and 15 nm in order from the substrate, and Si ₃ N ₄ was 40 nm, 65 nm and 65 nm in order from the substrate, as shown in the figure. It can be seen that the multilayer structure of this embodiment shows a peak of transmittance in the vicinity of 460 nm, which is a blue wavelength region, and almost no transmittance in other wavelength bands.

As can be seen in the embodiments 3 to 5, the transparent conductive film of the multilayer structure provided by the present invention may have a function of obtaining a high transmittance in a desired wavelength band and blocking other wavelength ranges. It can be used as a transparent conductive film material that also functions as). That is, when the transparent conductive film of the multilayer structure provided by the present invention is used as an electrode used as a transparent anode in a display such as an ELD or an OELD, an electrode for white light does not need to use a separate color filter even when an EL emitting white light is used. It is possible to realize a full color display with the transparent conductive film itself. It goes without saying that such a transparent conductive film having a multilayer structure can be used directly as an electrode of an EL display for monochromatic light.

Furthermore, when used as a transparent electrode film connected to a TFT-array that must transmit white light transmitted from a light guide plate, such as a TFT-LCD, there is no need to configure a separate color filter on the color filter substrate of the LCD. In addition, when the transparent conductive film of the present invention is used as a bus electrode of the front panel of a display such as PDP or FED, it can function not only as a transparent electrode film material but also as a color filter, thereby obtaining very useful results. Can be.

Example 6

As shown in FIG. 8, a structure different from the previous embodiment, the metal film is located at the top, and the transparent film and the metal film are shown in two layers of alternating structure. The thickness of each layer is as shown in FIG. 8. 20 nm and Si ₃ N ₄ was 80 nm. This embodiment shows that the selective transmittance seen in the previous embodiment can be obtained even when the lamination cycle is changed or the upper layer is a metal. In this embodiment, the peak of the transmittance is shown in the wavelength band around 530 nm which is a green region. Such a transparent conductive film having a multi-layer structure uses a metal electrode that is easy to emit electrons with a small work function, as well as a conventional electromagnetic wave shielding filter or a transparent electrode conductive film as shown in the above embodiment. It can be seen that it can also be used as a negative electrode material. In addition, in a conventional organic EL display using a single metal film as a negative electrode, as shown in FIG. 1, the transmittance is low so that the display function cannot be performed in the direction of the negative electrode. It can be used as a negative electrode because it is excellent, it is possible to manufacture a device that can display in both directions.

In the above embodiments, only one material is used as the transparent film and the metal film, respectively, but two or more types of materials may be used to form the multilayer structure. For example, Ag and Cu may be used as the metal film, and Si ₃ N ₄ and Al ₂ O ₃ may be used as the transparent film. In such a multi-layered multilayer structure, the type of material selected for each layer, the thickness of each layer is variable, and the wavelength region through which light is transmitted and the transmittance are determined.

In addition, although not mentioned in the above embodiments, a material such as Si ₃ N ₄ , which is a dielectric material used in the embodiments, may provide a sufficient passivation effect even when manufactured by the same method as conventional sputtering. By optical deposited to a thickness of several tens nm one such a recording film as a recording film material in the optical disc using a magnetic effect oxidation resistance is used for very large rare earth metals in the materials Tb is contained in both the recording film of a material such as Si ₃ N ₄ Poly Since durability can be obtained while using a substrate vulnerable to oxygen or water such as carbonate, the present invention provides a technology that can use a plastic substrate in a display using a material vulnerable to oxygen or water such as an OLED by using such a transparent layer. . In addition, unlike the conventional single oxide-based transparent conductive film, the transparent conductive film of the present invention can be applied to a material such as plastic because it does not need a high temperature synthesis process to obtain excellent conductivity.

In the above, the present invention has been illustrated and described with reference to specific preferred embodiments, but the present invention is not limited to the above-described embodiments and the general knowledge in the technical field to which the present invention pertains without departing from the spirit of the present invention. Various changes and modifications will be made by those who possess.

The transparent conductive film material having the multilayer structure of the transparent film / metal film according to the present invention as described above can not only provide excellent light transmittance and selective transmission of wavelength, but also contains a metal film excellent in electrical conductivity. At the same time, the conventional oxide-based transparent conductive film can be used as the transparent film material, thereby providing excellent conductivity. Therefore, the multi-layered transparent conductive film provided in the present invention can be used as a material for electrodes of flat panel displays requiring light transmittance and battery conductivity in the visible light region such as TFT-LCD, PDP, FED, ELD, and OELD, Depending on the design, it can have selective wavelength transmission, which can provide an advantage of simultaneously implementing the functions of the electrode and the color filter. In addition, since it provides excellent electrical conductivity including a metal film, it can also provide a function of shielding electromagnetic waves when used as a bus electrode of a PDP or FED, so that a function of transparent electrode film and electromagnetic shielding can be simultaneously obtained. Furthermore, as shown in the above embodiment, a design capable of blocking the wavelength region is also possible, so that it can be used as a multifunctional filter of PDP or FED as well as a transparent electrode film.

Claims (8)

A multi-layered thin film in which two or more transparent films and a metal film are alternately formed on a substrate, wherein the transparent film is a thin film formed using a material capable of transmitting light in the visible light region, and the metal film has a thickness of 5 layers. Is in the range of ~ 50nm, By controlling the number of alternating times or the thickness of each layer of the transparent film and the metal film to form a multi-layer structure characterized in that for controlling the light transmittance in the wavelength range of the desired light Transparent conductive film of wavelength selective multilayer structure. According to claim 1, wherein the transparent film forming the multi-layer structure is a dielectric material having a property of transmitting light in the visible region, an oxide material having a light transmission in the visible region and electrically conductive or a polymer that transmits the light in the visible region A transparent conductive film having a wavelength selective multilayer structure, wherein at least one material is selected. The method of claim 2, wherein the dielectric material is SiO ₂ , TiO ₂ , ZrO ₂ , HfO ₂ , Al ₂ O ₃ , ZnO, Y ₂ O ₃ , BeO, MgO, PbO ₂ , WO ₃ , VO _X , SiN _X , GeN as _{X, AlN, ZnS, CdS,} SiC, MgF, CaF 2, NaF, BaF 2, PbF 2, LiF, LaF 3, either or characterized in that two or more than two mixing compound is selected from the group consisting of GaP A transparent conductive film having a wavelength selective multilayer structure. The method of claim 2, wherein the oxide material is of the following groups, Sn added In ₂ O ₃ , F or Sb added SnO ₂ , Al, Ga, B, Y, In, Sc, Si, Ge, Ti, Zr, Hf, ZnO, In with one or more of N or F added Oxides with added impurities, such as added CdO, Mixtures of oxides such as Cd0, MgO, SnO ₂ , In ₂ O ₃ , ZnO, GaO, PbO ₂ , Tl ₂ O ₃ , Sb ₂ O ₅ , or oxides with impurities added thereto, or An oxide having a structure of AMO ₂ or an oxide having a structure in which a small amount of impurities are added to or substituted by an impurity, wherein A is a monovalent metal such as Cu, Ag, Li, Na, K, M is a trivalent metal such as Al, Ga, In, Tl, Sc, Y, La, A transparent conductive film having a wavelength-selective multilayer structure, wherein any one or two or more selected from oxides included in the oxide are mixed oxides. The method of claim 2, wherein the polymer material is polycarbonate, polymethyl methacrylate, polystyrene, polyester, polyethylene terephthalate and acrylic resin. A transparent conductive film having a wavelength-selective multilayer structure, wherein any one or two or more selected from the group consisting of a mixture is a compound. The method of claim 1, wherein the metal film forming the multilayer structure is Ag, Au, Cu, Pd, Pt, Ni, Al, Y, La, Mg, Ca, Li, K, Na, Cr, Mo, W, V , Ta, Co, Fe, Nb, Mn, Re, In, Sn, Zn, Pb or any one or more of these alloys, a transparent conductive film having a wavelength selective multilayer structure. The transparent conductive film of claim 1, wherein the multilayer conductive film is used as a transparent electrode of a flat panel display such as TFT-LCD, PDP, FED, ELD, OELD, and the like. The transparent conductive film having a wavelength selective multilayer structure according to claim 1, wherein the transparent conductive film having a multilayer structure is used for shielding electromagnetic waves.