KR20160056776A - nanostructure, preparing method thereof, and panel unit comprising the same - Google Patents

Abstract

Provided are nanostructure comprising a conductive region and a nonconductive region, a manufacturing method thereof, and a panel unit comprising the nanostructure. The conductive region includes at least one first nanowire, and the nonconductive region includes at least one second nanowire which is partially disconnected.

Description

The present invention relates to a nanostructure, a method of manufacturing the same, and a panel unit including the nanostructure,

A nanostructure, a method of manufacturing the same, and a panel unit including the nanostructure.

Various electronic products such as a liquid crystal display (LCD), an organic light emitting display (OLED), a touch screen and the like include indium tin oxide (ITO) Has been widely used.

However, since ITO is easy to break, it is difficult to be used for flexible displays and solar cells, and the price is rising. Therefore, there is a high demand for development of materials capable of replacing ITO.

One aspect provides a nanostructure and a method of manufacturing the same.

Another aspect of the present invention provides a panel unit including the nanostructure and having improved visibility between patterns.

According to one aspect, a semiconductor device includes a conductive region and a nonconductive region,

The conductive region containing at least one first nanowire,

The non-conductive region is provided with a nanostructure comprising at least one second nano-crystal region partially broken.

Wherein the average diameter of the second nanowires is smaller than the average diameter of the first nanowires and the difference between the average diameter of the first nanowires and the average diameter of the second nanowires is less than 5% Respectively.

A first step of forming a first nanowire layer comprising at least one first nanowire according to another aspect;

A second step of coating a material for a matrix on the first nanowire layer to produce a conductive film including the first nanowire and the matrix; And

And a third step of etching a part of the conductive film with an etching solution containing at least one selected from the group consisting of alkali metal hypochlorite and alkaline earth metal hypochlorous acid and in a weakly acidic condition or an alkaline condition to form the nanostructure Is provided.

Yet another aspect provides a panel unit comprising the above-described nanostructure.

The panel unit may be a flat panel display (FPD), a touch screen panel (TSP), a flexible display, or a foldable display.

When the nanostructure according to one embodiment is used, the problem of visibility between patterns can be solved because there is little difference in transmittance and haze between patterns.

FIG. 1 schematically shows the structure of a conductive film having a nanostructure according to one embodiment.
FIGS. 2A to 2D are views for explaining a manufacturing process of a conductive film having a nanostructure according to an embodiment.
Figure 3 illustrates the partial etch mechanism of nanowires using an etchant containing NaOCl.
4A schematically illustrates the structure of a second nanowire in a nanowire structure according to another embodiment.
Figure 4b schematically illustrates the structure of a second nanowire in a nanowire structure according to another embodiment.
FIG. 4C shows the total scattering cross-sectional area change according to the change of the etching shape of the silver nanowire.
FIGS. 5A and 5B are transmission electron micrographs of the nanowires produced according to Example 3. FIG.
FIG. 5C shows an optical microscope photograph of the nanowire fabricated according to Example 3. FIG.
FIGS. 5D and 5E are electron micrographs of nanowires prepared according to Example 3. FIG.
6 is an electron micrograph of a nanowire produced according to Comparative Example 1. FIG.
FIG. 7A is an optical microscope photograph of the nanowire produced according to Comparative Example 2. FIG.
7B and 7C are electron micrographs of nanowires prepared according to Comparative Example 2. FIG.
FIGS. 8A to 8F show X-ray photoelectron spectroscopic analysis results in an etched region (non-conductive region) in the nanowire fabricated according to Example 1. FIG.
FIGS. 9A to 9C show the results of a high angle annular dark field scanning transmission electron microscope (HAADF-STEM) analysis in the etched region in the nanowire fabricated according to Example 3. FIG.
10A to 10D are electron micrographs of nanowires prepared according to Examples 4 to 6. FIG.
FIG. 11A shows a transmission electron microscope photograph of the nanowire prior to the etching.
11 (b) is a transmission electron micrograph of the nanowire fabricated according to Example 6. FIG.
FIG. 11C is a transmission electron microscope photograph of the nanowire fabricated according to Example 8. FIG.
12 schematically illustrates the structure of a touch screen panel including a nanostructure according to an embodiment.
13 is a schematic view illustrating a structure of a liquid crystal display device including a nanostructure according to an embodiment.
FIG. 14 schematically shows the structure of a plasma display panel including a nanostructure according to an embodiment.
FIGS. 15A to 15E are obtained by analyzing the areas of the nanostructures prepared according to Examples 1, 2, 13, and 3 and Comparative Example 4 using an electron scanning microscope.
FIGS. 16A to 16E are electron micrographs of nanostructures prepared according to Example 2, showing the change in optical microstructure as the etching time elapses. FIG.
17 shows the difference in the transmittance and the haze of the etched region and the non-etched region with respect to the etching time in the nanostructure produced according to Example 2. FIG.
18A schematically shows a structure of a device used in reliability evaluation in Evaluation Example 8. Fig.
18B is a view showing a reliability evaluation result of the nanostructure produced according to Example 1. FIG.
Fig. 18C is a diagram showing the reliability evaluation results of the nanostructures produced according to Example 1 and Comparative Example 4. Fig.

The nanostructure according to one embodiment comprises a conductive region and a nonconductive region, wherein the conductive region contains at least one first nanowire and the non-conductive region comprises at least one partially broken Lt; / RTI > of the second nano and porosity.

The non-conductive region has a surface resistance of 10 ⁹ Ω / □ or more, for example, 10 ¹⁰ Ω / □ It does not have conductivity due to infinite surface resistance. Therefore, even when the time passes, the non-conductive property is maintained, so that the reliability of the insulation part is excellent.

The nanostructure described above is characterized in that the average diameter of the second nanowire is smaller than the average diameter of the first nanowire and the difference in the average diameter of the second nanowire and the first nanowire is reduced to 5% Of the total etch rate

As a material that can replace the ITO electrode, a transparent conductive film containing silver nanowires (AgNWs) may be used. In order to form a transparent conductive film containing nanowires, for example, a mixture of phosphoric acid and nitric acid or a mixture of phosphoric acid, nitric acid and acetic acid is generally used as an etching solution. In the case of forming a transparent conductive film containing silver nanowires by using such an etching solution, the time is elapsed even though the visibility is improved due to visibility or partial etching between the patterns due to the difference in transmittance and haze between the patterns after etching. Etching may be additionally progressed to be visible between the patterns. Conversely, if the time elapses, if the nanowire is subjected to an external electrical force in the etched region, the conductive path may be re-formed and the reliability of the wiring may deteriorate.

Also, an insulating layer may be formed on the surface of the second nanowire in the non-conductive region in the nanostructure according to an embodiment. If the insulating film is formed as described above, even if the time passes in the conventional technique, the etching further proceeds to cause a visibility problem. On the contrary, the advantage of being able to prevent the problem of reformation of the conductive path due to the electrical external force is improved, can do. Therefore, the insulating property can be maintained even if the time passes in the non-conductive region (insulating portion).

It is noted that the overall light scattering of the nanostructure depends mainly on the diameter change rather than the length of the nanowire (see FIG. 4C), so that the average diameter of the second nanowires present in the non-conductive region is larger than the average diameter of the first nanowires The average diameter difference is smaller than the average diameter, and the partial etching is induced so that the average diameter difference between the second nanowire and the first nanowire is within 5%. Thus, the etching process of the second nanowire in the non-conductive region is controlled to control the shape of the second nanowire. Accordingly, the nanostructure according to an embodiment uses a shape of the nanowire when forming a nanowire pattern, a nanostructure pattern generated due to a change in transmittance, a refractive index, and a haze of each region using a correlation of optical characteristics such as transmittance, haze, It is possible to effectively solve the visibility problem of the display device. The use of nanostructures according to one embodiment eliminates the need for additional light diffusing layers.

Referring to FIG. 4C, it can be seen that when the average diameter of the nanowires is reduced (see c), the overall scattering cross-sectional area is reduced compared with the case where the average length of the nanowires is reduced (see FIG. In Figure 4c a is the average length of the nanowires and the state before reducing the average diameter.

The average diameter of the second nanowires is smaller than the average diameter of the first nanowires. The difference between the average diameter of the first nanowire and the average diameter of the second nanowire is 5% or less, for example, 0.01 to 5%, specifically 0.02 to 3%, of the average diameter of the first nanowire. Under these conditions, since the increase in transmittance and the decrease in haze in the non-conductive region are small, the problem of visibility of the pattern of the regions in the nanostructure is solved.

The average diameter of the first nanowires is between 10 and 100 nm, for example between 15 and 50 nm, and the average diameter of the second nanowires is between 9.5 and 95 nm, for example between 14 and 47.5 nm.

The difference between the average diameter of the first nanowire and the average diameter of the second nanowire may be between 0.5 and 5 nm.

The average length difference of the second nanowires present in the non-conductive region is smaller than that of the first nanowire. The difference between the average length of the first nanowires and the average length of the second nanowires is 20% of the average length of the first nanowires, for example, 10% or less, specifically 0.01 to 10%.

The average length of the first nanowire is between 3 and 200 탆, for example between 50 and 100 탆, and the average length of the second nanowire is between 2.4 and 80 탆, for example between 10 and 50 urn, for example between 8 and 40 탆 to be.

The difference between the average length of the first nanowire and the average length of the second nanowire may be between 0.6 and 20 mu m.

The sheet resistance difference between the conductive region and the non-conductive region is at least 10 ⁹ Ω / □ or more.

In the non-conductive region, the average diameter deviation of at least one second nanowire is 5 to 10 nm and the average length deviation is 2 to 10 탆. On the contrary, the average diameter deviation of at least one first nanowire in the conductive region is 1 to 5 nm, and the average length deviation is 2 to 5 탆. Thus, the first nanowire has a more constant diameter and length than the second nanowire.

The aspect ratio of the second nanowire is 1 to 500, and the aspect ratio of the first nanowire is 20 to 10,000. And the aspect uniformity of the second nanowire is 90% or more, for example, 90 to 95%. The aspect uniformity of the second nanowire is 90% or more, for example, 90 to 95%. Here, the aspect ratio uniformity is obtained by calculating each of the approximations of about 10 second nanowires, and calculating the deviation of them, as the aspect ratio uniformity. On the other hand, the aspect ratio of the first nanowire is less than 90%, which is smaller than that of the second nanowire.

In the case of using the nanostructure including the first nanowire and the second nanowire having the average diameter, the average length and the aspect ratio described above, the problem of visibility of the pattern caused by the difference in haze, Can be solved.

The first nanowire and the second nanowire may be at least one selected from the group consisting of a metal, a metal alloy, a metal sulfide, a metal chalcogen compound, a metal halide, and a semiconductor.

The first nanowire and the second nanowire may be formed of, for example, iron (Fe), platinum (Pt), nickel (Ni), cobalt (Co), aluminum (Al), silver (Ag) (Cu), silicon (Si), germanium (Ge), cadmium sulfide (CdS), selenium sulfide (CdSe), cadmium telluride (CdTe), zinc sulfide (ZnS), zinc selenide (ZnSe) (GaAs), gallium arsenide (GaAs), gallium arsenide (GaSb), aluminum nitride (AlN), aluminum phosphate (AlP), aluminum arsenic (AlAs), aluminum antimony ), the group consisting of indium phosphide (InP), indium arsenide (InAs), indium antimony (InSb), silicon carbide (SiC), iron platinum (FePt), iron oxide (Fe ₂ O ₃₎ and iron oxide (Fe ₃ O ₄₎ ≪ / RTI >

According to one embodiment, the first nanowire and the second nanowire are made of silver (Ag).

According to another embodiment, as shown in FIG. 4A, the non-conductive region of the nanostructure may further include a second nanowire having a region having a very small average diameter as compared with other regions. Thus, a region having a very small diameter as compared with other regions can be called a " non-conductive bridge ". The average diameter of the non-conductive bridge can be controlled to be smaller than, for example, the average diameter in other areas of the second nanowire.

And is substantially non-conductive with a resistance of, for example, 10 ⁹ Ω / □ or higher in the non-conductive bridge in the second nanowire.

The nanostructure according to another embodiment has a second nanowire (hereinafter referred to as " second nanowire A ") having an average diameter difference of less than 5% of the first nanowire of the conductive region with the nonconductive bridge described above And a second nanowire (hereinafter referred to as " second nanowire B ").

The nanostructure according to another embodiment may have a non-conductive region by forming an insulating film between a plurality of nanowires as shown in FIG. 4B.

The nanostructure according to another embodiment includes a second nanowire (hereinafter referred to as " second nanowire C ") having a structure in which an insulating film is formed between the second nanowire A and a plurality of second nanowires ≪ / RTI >

The nanostructure according to another embodiment may contain both the second nanowire A, the second nanowire B, and the second nanowire C.

The mixing ratio of the second nanowire A, the second nanowire B, and the second nanowire C may be variously changed. The content of the second nanowires B and the second nanowires C may be 0.1 to 50 parts by weight based on 100 parts by weight of the second nanowires A. [

The first nanowire forms a conductive network structure. Here, the conductive network has a surface resistance of 10 ⁶ Ω / □ or less, for example, a surface resistance of 10 ⁵ Ω / □ or less, specifically 10 to 1000 Ω / □.

A polymer membrane may be formed on at least a part of the surface of the first nanowire. Wherein the polymer membrane is selected from the group consisting of polyvinylpyrrolidone, polystyrene, polyethyleneimine, polyphosphagene, polylactide, polylactide-co-glycolide, polycaprolactone, polyanhydride, At least one polymer selected from the group consisting of polyacrylates, polyacrylates, polyacrylates, polyacrylates, polyacrylates, polyacrylates, polyacrylates, polyacrylates, polyhydroxybutyrates, polycarbonates and polyorthoesters, polyethylene glycols, poly-L-lysine, polyglycolides and polymethylmethacrylates.

Since nanowires are generally very small in size, they tend to cohere with each other because of their strong surface tension. Therefore, as described above, the polymer membrane must be formed on the surface of the nanowire to protect each nanowire while increasing the dispersibility of the nanowire.

As with the first nanowire, the above-described polymer membrane can be formed only on at least a part of the surface of the second nanowire.

An insulating film may be formed on at least a part of the surface of the second nanowire. If the insulating film is formed as described above, unlike the conventional case, it is possible to prevent the conductive path from being formed again due to an external external force even if the time elapses.

The insulating film may include at least one selected from the group consisting of silver chloride (AgCl) and silver oxide. At this time, the thickness of the insulating film is not particularly limited. For example, 0.0001 to 10 nm.

 The transmittance of the non-conductive region is larger than the transmittance of the conductive region, and the difference of the transmittance of the non-conductive region and the transmittance of the conductive region is 0.1% or less, for example, 0.01 to 0.1% of the transmittance of the non-conductive region.

The haze of the non-conductive region is smaller than the haze of the conductive region, and the difference in haze of the non-conductive region and the conductive region is 0.2% or less of the haze of the non-conductive region, for example, 0.01 to 0.15%.

The surface resistance of the non-conductive region is larger than the surface resistance of the conductive region, and the difference in surface resistance between the non-conductive region and the conductive region is 10 ⁹ Ω / □ or more, for example, 10 ¹⁰ Ω / □ or more.

The non-conductive region has a transmittance of more than 90%, a haze of 1% or less, and a surface resistivity of 10 ⁹ Ω / □ or more. The transmittance is, for example, 90.2 to 95%, and the haze is, for example, 0.7 to 0.9%.

In this specification, the transmittance refers to the percentage of incident light transmitted through the medium. The permeability of the nanostructure is at least 80 to 98%.

Haze is an index of light diffusion, which refers to the percentage of light scattered and transmitted through the incident light. The haze of the nanostructure is 10% or less, for example, 5% or less. According to another embodiment, the haze of the nanostructure is 2% or less, for example, 1% or less, specifically 0.25% or less.

The conductive and non-conductive regions in the nanostructure further include a matrix. The matrix is a solid material in which the nano and the earth are dispersed or buried in order to protect the nano and the earth so that the nano and the earth do not wear or corrode. Some of the nanowires in the conductive and non-conductive regions may be exposed or protruded from the polymer matrix to be accessible to the conductive network.

The matrix may be selected from the group consisting of polyurethane, polyester, polyacrylic, polymethacrylic, polyether, cellulose resin, polyvinyl alcohol, epoxy resin, polyvinylpyrrolidone, polystyrene, polyethylene glycol, polyaniline, Polytetrafluoroethylene, polytetrafluoroethylene, polytetrafluoroethylene, polytetrafluoroethylene, polytetrafluoroethylene, polytetrafluoroethylene, polyphenylene sulfone, And the matrix may have a thickness of 10 nm to 5 μm, for example, 50-200 nm.

The matrix may further comprise an inorganic material. As the inorganic material, for example, silica (SiO ₂ ), alumina (Al ₂ O ₃ ), silicon carbide (SiC), alumina-silica (Al ₂ O ₃ -SiO ₂ ) When such an inorganic material is further added to the matrix, it is possible to manufacture a nanostructure having reduced glare by controlling light diffusion and the like.

The nanostructure according to one embodiment may further include an overcoat layer. The overcoat layer can be formed to stabilize and protect the conductive network of the nanostructure and to improve optical properties such as anti-glare and anti-reflection.

The overcoat layer can be, for example, an antireflection layer, a protective layer, a barrier layer, or a hard coat layer. The antireflective layer may comprise, for example, colloidal silica, light scattering materials such as fumed silica, siloxane, polythiophene, polypyrrole, polyurethane and the like. The protective film may include polyester, polyethylene terephthalate, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polyethylene, and the like.

According to another aspect, there is provided a conductive film comprising a substrate and a nanostructure formed on the substrate. Such a conductive film can be used as an optical film.

FIG. 1 is a schematic view illustrating a structure of a conductive film including a nanostructure according to an embodiment. Referring to FIG.

Referring to this, the conductive film has a structure in which the nanostructure 11 is formed on the substrate 10. The nanostructure 11 includes a conductive region 12a and a non-conductive region 12b. The nanostructure 11 may further include a matrix 15.

The conductive region 12a contains at least one first nanowire 13

The non-conductive region 12b contains at least one second nanowire 14 partially broken. The non-conductive region 12b maintains the insulation property even after a lapse of time. The difference in haze, transmittance, and refractive index between the conductive region 12a and the non-conductive region 12b is small, so that the problem of visibility between the nanowire patterns can be prevented in advance.

2A to 2D, a method of manufacturing a conductive film having a nanostructure according to an embodiment will be described.

First, a conductive film including a first nanowire 23 and a matrix 25 is formed on a substrate 20 (Fig. 2A). Here, the thickness of the conductive film is 0.1 to 10 탆, for example, 1 to 150 nm, for example, about 100 nm.

Any material can be used as long as the base material 20 is transparent and does not inhibit the passage of light, and has elasticity and durability characteristics corresponding to the intended use.

For example, there are various kinds of materials such as polyethylene terephthalate (PET), polycarbonate (PC), polymethylmethacrylate (PMMA), polyethylenenaphthalate (PEN), polyethersulfone (PES) , A cyclic olefin copolymer (COC), a triacetylcellulose (TAC), a polyvinyl alcohol (PVA), a polyimide (PI), and a polystyrene (PS) Or more.

The thickness of the substrate is in the range of 10 to 200 μm, depending on the application of the device to be applied within the range of the production of the film itself.

The conductive film including the first nanowires 23 and the matrix 25 is formed by forming a first nanowire layer on the substrate 20 and applying and drying a composition for forming a matrix thereon. The above-mentioned first nanowire layer contains a plurality of nanowires and is formed to have a predetermined thickness on the substrate.

Silver nanowires can be used as the first nanowire.

The silver nanowires can be formed by using a mold such as a carbon nanotube or a polycarbonate membrane, a method using nanoparticles of silver bromide (AgBr) and silver nitrate (AgNO ₃ ), a method using two silver electrodes (NaNO ₃ ) and arc discharge, and a method of reducing by using polymers such as polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP). However, the synthesis of silver nanowires is not limited to the above-described method, but may be performed by various other methods. Such a silver nanowire can form a silver nanowire layer together with a predetermined solvent.

The matrix 25 may be formed using a polymer having a transmittance of 85% or more in a visible light region. Examples of such a polymer include polyurethane resins, polyester resins, acrylic resins, polyether resins, cellulose resins, polyvinyl alcohol resins, epoxy resins, polyvinyl pyrrolidone, polystyrene resins, polyethylene glycol , Pentaerythritol, polypyrrole, and the like, or a mixture of two or more thereof.

The composition for forming a matrix includes a matrix-forming polymer, a dispersion stabilizer and a solvent. As the solvent, at least one selected from ultrapure water, alcohol, ketone, ether, hydrocarbon and aromatic compounds is used. Here, ethanol, isopropanol or the like is used as an alcohol.

The coating method of the above-mentioned matrix-forming composition is not particularly limited, and examples thereof include a spin coating method, a slit coating method, a bead coating method, a spray coating method, a printing method and a dip coating method.

Instead of the matrix-forming polymer, a prepolymer or a monomer that can be used in the production of the matrix-forming polymer may be added. When a prepolymer or a monomer is used, a composition for forming a matrix containing a prepolymer or a monomer is applied on the first nanowire layer, and then light or heat is applied. Through the process of applying light or heat, the prepolymer or the monomer forms a matrix-forming polymer corresponding thereto.

The prepolymer or monomer may be any of those used in the art. Non-limiting examples include alkyl or hydroxyalkyl acrylates such as methyl, ethyl, butyl, 2-ethylhexyl and 2-hydroxyethyl acrylate, isobornyl acrylate, methyl methacrylate and ethyl methacrylate, (Meth) acrylamides, vinyl esters such as vinyl acetate, isobutyl vinyl ether, styrene, N-vinylpyrrolidone, N-vinylpyrrolidone, Diacrylates of vinylidene chloride, vinyl chloride and vinylidene chloride, ethylene glycol, propylene glycol, neopentyl glycol, hexamethylene glycol and bisphenol A, and 4,4'-bis (2-acryl Acryloyloxyethoxy) diphenylpropane, vinyl acrylate, divinylbenzene, divinyl succinate, dianilphthalate, triallylphosphate, But are not limited to, triallyl phosphate, triallyl isocyanurate, tris (2-acryloylethyl) isocyanurate, epoxy resin, acrylicized epoxy resins, Polyesters, polyurethanes and polyethers, unsaturated polyester resins, and the like, including acrylicized polyesters, vinyl ethers or epoxy groups.

In the case where light or heat is applied as described above, a polymerization initiator is added to the composition for forming a matrix.

A photopolymerization initiator or a thermal polymerization initiator may be used. The photopolymerization initiator can be used without limitation in the constitution as long as it is a compound capable of forming a radical by light such as ultraviolet rays. Examples of the photopolymerization initiator include 2-hydroxy-2-methyl-1-phenyl-propan-1-one (HMPP), benzoin ether, dialkyl acetophenone, At least one member selected from the group consisting of hydroxyl alkylketone, phenyl glyoxylate, benzyl dimethyl ketal, acyl phosphine and alpha-aminoketone, Can be used.

As the thermal polymerization initiator, at least one selected from persulfate-based initiators, azo-based initiators, initiators consisting of hydrogen peroxide and ascorbic acid can be used. Specifically, examples of persulfate-based initiators include sodium persulfate (Na2S2O8), potassium persulfate (K2S2O8), ammonium persulfate (NH4) 2S2O8, and the like. Azo Examples of the initiator include 2, 2-azobis (2-amidinopropane) dihydrochloride, 2,2-azobis- (N, N-dimethylene) isobutane Azobis- (N, N-dimethylene) isobutyramidine dihydrochloride, 2- (carbamoyl azo) isobutylonitrile, 2, 2-azobis Azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride), 4,4-azobis- ( 4-azobis- (4-cyanovaleric acid), and the like. And the content of the polymerization initiator is used at a usual level.

The dispersion stabilizer is a substance that helps each component to be stably dispersed in a composition for forming a matrix. Examples of the dispersion stabilizer include N, N-formamide, N, N-diacetamide, methylcellulose, ethylcellulose, hydroxypropylcellulose , Polyvinyl alcohol, polyvinyl methyl ether, polyacrylic acid, polyvinyl acetate, polyvinyl pyrrolidone, a copolymer of vinyl pyrrolidone and vinyl acetate, and the like. The content of such a dispersion stabilizer is used at a usual level.

2B, a mask pattern 26 is formed on a part of the conductive film (first region), and a second region of the conductive film on which the mask pattern is not formed is brought into contact with the etchant (FIG. 2B). Here, the second region corresponds to the non-conductive region 22b.

The above-described mask pattern can be formed according to a general photolithography process. A photoresist film may be formed on the conductive film and patterned to form the mask pattern 26 only on the first region of the conductive film. Here, the first region corresponds to the conductive region 22a.

The mask pattern 26 may be used as shown in FIG. 2B to contact the etching solution only in the second region of the conductive film as described above. However, it is also possible to use another method without such a mask pattern 26. [ As a method capable of applying the etching solution only to the second region of the conductive film, a spray coating method, a printing method, a doctor blade method, or the like can be used.

In the process of contacting only the second region of the conductive film with the etching solution, the partial etching of the second nanowire proceeds. The partial etching mechanism will be described as follows.

First, the etchant passes through the matrix to oxidize the silver nanowire surface. Subsequently, the silver ion and the anion of the etchant are combined with each other to appropriately adjust the etching time, thereby achieving the partial etching.

As shown in FIG. 2B, when the etchant is brought into contact with the second region of the conductive film, the polymer forming the matrix (polymer matrix) is swollen to expand the free space. The ions of the etchant diffuse and move through the extended free space to oxidize the surface of the second nanowire in the non-masking region, and the silver ions and the etchant react with each other to progress the partial etching. The ions of the etchant are, for example, PO ₄ ³ - of the etchant and NO ₃ ^- of the oxidant.

As shown in FIG. 2C, the etching time is adjusted so that the silver nanowires are partially etched so as to be electrically insulated without removing them, so that the non-masking region (non-conductive region 22b) A conductive film including at least one second nanowire 24 partially cut off and a matrix 25 is formed. When the mask is removed from the thus obtained resultant, the nanostructure 21 is formed on the substrate 20 as shown in FIG. 2D. The nanostructure 21 has a structure including a conductive region including a first nanowire 23 and a non-conductive region including a matrix 25, including at least one second nanowire 24 partially broken .

A method of dipping the second region of the conductive film in an etching solution in a process of contacting the second region of the conductive film with the etching solution, a method of spray coating an etchant in the second region of the conductive film, or the like. Among them, spray coating is advantageous for mass production of nanostructures.

The etching time depends on the kind of the etching solution, the method of contacting the conductive film and the etching solution, and the like. The etching time is, for example, 10 seconds to 10 minutes, for example, 30 seconds to 120 seconds. When the etching time is in the above range, there is no difference in haze and light transmittance of the conductive film having the nanostructure without etching the first region of the nanowire corresponding to the conductive region, so that the visibility problem can be solved and mass production becomes possible .

The etching solution contains at least one metal hypochlorite selected from alkali metal hypochlorite or alkaline earth metal hypochlorite as an essential component. The content of the hypochlorous acid metal salt as an essential ingredient is 1 to 30% by weight based on the weight of the etchant.

The content of the metal hypochlorite in the etching solution may be slightly changed depending on the object to be etched (structure of the nanostructure). For example, if the nanostructure comprises a first nanowire and a second nanowire having a conductive region and a non-conductive region, if the matrix further contains a matrix, the content of the hypochlorite metal salt in the etchant can be controlled according to the degree of curing of the matrix. have. For example, the content of the metal hypochlorite in the etching solution may be 1 to 30% by weight, for example, 5 to 20% by weight. In the case where the nanostructure does not contain a matrix, the content of the metal hypochlorite in the etching solution may be in the range of 1 to 5 wt%, for example, in the range of 2 to 5 wt%. In the case where the nanostructure does not contain a matrix, etching can be performed using a smaller amount of metal hypochlorite than when a matrix is further contained.

The metal hypochlorite may be dissolved in a solvent such as deionized water and used appropriately. The concentration of the metal hypochlorite is, for example, 5 to 20% by weight. When a metal hypochlorite having such a concentration is used, a nanostructure having desired optical characteristics can be obtained by adjusting the etching rate, the etching time, and the like.

The etchant may contain an oxidizing agent and a solvent in addition to the above-described metal hypochlorite metal salt. The etchant may further include a general etchant.

The oxidizing agent may be any material that is commonly used in the art. The oxidizing agent uses at least one selected from the group consisting of, for example, peroxide, persulfide, peroxo compound, metal oxide salt, organic oxidizing agent and gas oxidizing agent.

Examples of peroxides include nitric acid, hydrogen peroxide, or potassium permanganate (KMnO ₄ ), examples of persulfates include ammonium persulfate, and examples of peroxo compounds are sodium persulfate or potassium persulfate. Examples of the metal oxide salt include palladium, magnesium, cobalt, copper or a silver-containing salt.

The gas oxidizing agent includes air, oxygen or ozone. Examples of the organic oxidizing agent include iron chloride, copper chloride, and 7,7 ', 8, 8'-tetracyanoquinodimethane.

If silver nanowires are used as nanowires, the oxidant reacts with silver nanowires to convert silver to silver oxide.

The oxidizing agent content is used at a conventional level. For example, 0.1 to 10% by weight based on the total weight of the etchant. When the content of the oxidizing agent is in the above range, there is no difference in haze and light transmittance, so that the problem of visibility between patterns can be solved.

The etchant may be any material that is commonly used in the art. The etchant may be at least one selected from the group consisting of phosphoric acid, acetic acid, sodium nitrate (NaNO ₃ ), ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ) and halides.

Examples of the halide include iodide (I ₂ ), chloride, bromide and the like. Here, the content of the etchant is a usual level, and 1 to 100 parts by weight is used based on 100 parts by weight of the metal hypochlorite metal salt.

The solvent may be water, alcohol or the like. The content of the solvent is used at a conventional level. Is controlled to 5 to 30% by weight based on the total weight of the etchant.

The pH of the etchant at the time of etching should be adjusted so as to control the nanowire mean diameter difference in the etched region and the non-etched region within an appropriate range, for example, within 5% while the polymer of the polymer membrane existing on the surface of the nanowire is well removed. The pH of such an etching solution is adjusted to a weakly acidic condition or an alkaline conditional range.

In the slightly acidic condition, the pH of the etching solution is 3 to 6, for example, 3 to 4. The alkali condition is adjusted to a pH of 10 or more, for example, 11.5 or more, specifically 12 to 13. When the pH is in the above range, not only the visibility of the pattern is solved but also the reliability of the insulating part is improved. If the pH of the etching solution exceeds the above range, excessive etching of the nanowires causes a difference in haze, transmittance, and refractive index of each region, so that the problem of visibility between patterns still remains. If the pH of the etching solution is less than the above range, the polymer film such as polyvinyl pyrrolidone existing on the surface of the nanowire still remains and the etching rate of the nanowire is too small. In this case, the difference in haze, It becomes difficult.

The etching solution may further include a reaction retarder, a pH adjusting agent, and the like.

Examples of the reaction retarder include sodium carbonate (Na ₂ CO ₃ ), sodium phosphate (Na ₃ PO ₄ ), sodium phosphate hydrate (Na ₃ PO ₄ .12H ₂ O), and the like. Sodium polyphosphate (Na ₅ P ₃ O ₁₀ ), sodium pyrophosphate (Na ₄ P ₂ O ₇ ), sodium pyrophosphate hydrate (Na ₄ P ₂ O ₇ .10H ₂ O), sodium ethylenediaminetetraacetate sodium hydrate (Na ₄ EDTA · 10H ₂ O). The content of such a retarder is a conventional level.

The pH adjuster may be ammonia water, sodium hydroxide solution or the like so that the pH of the etchant can be controlled in an alkaline condition, which is used when adjusting the pH of the etchant to an alkaline condition, for example, 10 or more, specifically 11.5 or more.

The nanostructure produced according to the above-described process can be further post-treated. Examples of the post-treatment include plasma treatment, corona discharge, UV-ozone, heating and pressurizing processes, and the like.

3 is a view for explaining a mechanism in which polyvinylpyrrolidone (PVP) coated on a nanowire surface in an alkali solution reacts with a metal hypochlorite to open a ring of PVP.

With reference to this, polyvinylpyrrolidone (PVP) reacts with sodium hypochlorite to form compound (I) and sodium chloride. Compound (I) then forms compound (II) in the presence of hydroxide ion (OH-). Compound (II) then reacts with the hydroxide ion (OH ^- ) to open the ring of PVP.

In this reaction, the hydroxide ion must be provided as a reactant to open the loop of PVP. Since the chains of the polymer such as PVP are easily broken in the alkali solution, the etching containing the PVP elimination reaction can proceed easily under the alkaline condition.

Figure 4a illustrates a second nanowire in a nanostructure according to another embodiment.

Referring to this, a PVP film 41 is formed on the second nanowire 40 and the second nanowire 40 ', and the second nanowire 40 and the second nanowire 40' And can have a non-conductive bridge 42. At this time, the non-conductive bridge 42 has a resistance of 10 < ⁹ > or more and is substantially non-conductive. The average diameter of the non-conductive bridge 42 is 50% or less, for example, 0.01 to 30% of the average diameter of the second nanowire 40 and the second nanowire 40 '. As described above, the average diameter of the non-conductive bridge has a very small average diameter as compared with the other regions, and the conductivity may not be substantially represented.

An insulating film may be further formed on the non-conductive bridge. Here, the insulating film may include at least one selected from silver chloride and silver oxide.

FIG. 4B illustrates the structure of a second nanowire in a nanostructure according to another embodiment.

Referring to FIG. 2, a part of the PVP film 41 coated on the second nanowire 40 is removed and an insulating film 43 is formed between the second nanowires 40 and 41 to have a non-conductive region.

According to one embodiment, in the method of manufacturing a nanostructure containing silver nanowires as a nanostructure, after the etching process of the second nanowire forming the non-conductive region, the etching structure of the silver nanowire has a uniform diameter . Because of this shape, the scattering change in the nanowire region is small, so that there is little difference in haze and transparency before and after the patterning, thereby solving the problem that the nanowire pattern is visible.

Applying an oxidizing agent that can uniformly remove the PVP film surrounding the nanowire minimizes the diameter variation of the silver nanowire and uniformly disconnects the nanowire. In the alkali solution of pH 11.5 or higher, hypochlorous acid metal salt such as sodium hypochlorite can uniformly remove the PVP, so that the thickness of the silver nanowire can be uniformly cut without changing much. In addition, since an etchant containing a metal hypochlorite can be applied to form an insulator such as silver chloride (AgCl) by reacting with the silver ions of the nanowire after the oxidation process, the problem that the partially etched silver nanowires are connected over time Can be effectively solved.

It can be shown that the average diameter difference between the second nanowire and the first nanowire has a greater effect on the light scattering change than the average length difference in the formation of the non-conductive region.

The haze of a nanowire is generated by light scattering in the vicinity of the silver nanowire.

By Rayleigh scattering theory, silver nanowires are considered to be electric linear dipoles. (Rayleigh dipole approximation) At this time, the overall light scattering cross-sectional area is determined by the following equations (1) to (3).

[Formula 1]

　　　　　　　　　　　　　　

　　　　　　　　　　　　　　

[Formula 2]

　　　　　　　

　　　　　　　

[Formula 3]

　　　　　　　　　　　　　　　　　　　　　　　

　　　　　　　　　　　　　　　　　　　　　　　

In the above equations (1) to (3),? Scat denotes a total scattering cross section,

a is the radius of the silver nanowire,

L is the length of the silver nanowire and is generally assumed to be L " a,

n _p is the complex refractive index of the silver nanowire,

n _m is the refractive index of the medium surrounding the silver nanowire.

It can be seen from Equation 1 that the light scattering in the vicinity of the silver nanowire is proportional to the fourth power of the radius of the silver nanowire and is proportional to the first power of the length, as shown in the following equation (4). That is, the smaller the diameter of the silver nanowire is, the smaller the haze is, and the length is less affected than the diameter.

[Formula 4]

σ _scat α d ⁴ , σ _scat α L

In Equation 4,? Scat denotes a total scattering cross section.

Figure 4c shows the overall scattering cross-sectional area change depending on the etched shape of the silver nanowire based on the Rayleigh scattering theory. In Fig. 4C, the length of the silver nanowires was about 15 mu m and the diameter was about 20 nm.

Referring to FIG. 4C, the change in light scattering is shown when the diameter and length of the nanowire are reduced to two thirds of their original diameter and length, respectively. If the diameter of the nanowire is not changed by the etching of the nanowire, the change in light scattering, i.e., haze, can be greatly reduced. Therefore, if the theoretical result is applied to the partial etching of the nanowire according to an embodiment, in order to solve the pattern after-view problem of the silver nanowire, the permeability and haze difference before and after the etching must be minimized. The diameter of the nanowire can be broken only in the longitudinal direction without significantly changing. In this case, it is possible to solve the problem that the haze difference is small after the patterning of the nanowires, thereby visually recognizing the pattern.

According to another aspect, there is provided a panel unit including the above-described nanostructure.

The nanostructure can be used as a transparent electrode that can replace the ITO electrode.

Examples of the panel unit include a flat panel display (FPD), a touch screen panel (TSP), a flexible display, or a foldable display.

Examples of the flat panel display include a liquid crystal display (LCD), a plasma display panel (PDP), and the like.

The flexible display or the foldable display provides flexibility to fold and unfold a substrate surrounding a liquid crystal in a liquid crystal display device or the like as a plastic film. Such a flexible display or a foldable display is advantageous not only in thickness and lightness but also in impact, and can be bent or bent and manufactured in various forms. Even if it is dropped, it can be handled with a thin and thin shape which can not be broken, and it is possible to form a curved surface, thereby enlarging a display application area.

Examples of the flexible display include a plasma display panel, a liquid crystal display, a mobile phone, a tablet, an electronic paper (E-paper), and a wearable display.

12 schematically illustrates the structure of a touch screen panel including a nanostructure according to an embodiment.

The touch screen panel device 640 includes a first substrate 644 that is coated or laminated with a first conductive layer 646 having a top conductive surface 648.

The upper panel 650 is disposed opposite from the lower panel 642 and separated therefrom by adhesive enclosures 652 and 652 'at the respective ends of the device 640. The top panel 650 includes a second conductive layer 654 coated or laminated on a second substrate 656. The second conductive layer 654 has an inner conductive surface 658 facing the conductive surface 648 and is hung on top of the spacer 660.

When the user touches the top panel 650, the inner conductive surface 658 and the top conductive surface 648 of the bottom panel 642 become electrical contacts. A contact resistance is generated, which causes a change in the electrostatic field. A controller (not shown) senses such changes and resolves the actual touch coordinates, after which information is passed to the operating system.

At least one of the first conductive layer 646 and the second conductive layer 654 uses a nanostructure according to an embodiment.

The above-described touch screen panel may have a capacitive type.

13 schematically shows the structure of a liquid crystal display (LCD), which is one of flat panel display panels including a nanostructure according to an embodiment of the present invention.

13 is a cross-sectional view of a top gate thin film transistor-based liquid crystal display device.

In the top gate type thin film transistor, the gate electrode is disposed above the active layer.

The LCD 542 has a color filter substrate 546 having a liquid crystal layer 548 interposed therebetween and a TFT substrate 544. In the TFT substrate 544, the thin film transistors 550 and the pixel electrodes 552 are arranged in a matrix configuration on the lower transparent substrate 554, as described above. The common electrode 556 can be applied with a common voltage and the color filter 558 is disposed on the top transparent substrate 560. The voltage applied between the pixel electrode 552 and the common electrode 556 drives the liquid crystal cells (pixels), and the pixel electrode 552 and the common electrode 556 are opposed to each other with the liquid crystal 548 therebetween. watching.

The thin film transistors 550 disposed for each of the pixels on the lower transparent substrate 554 are top gate type TFTs and their gate electrodes 562 are disposed on the active layer 564. [ The active layer 564 of the TFT is patterned on the lower substrate 554 according to methods known in the art. A gate insulating layer 566 is disposed on the active layer 564 to cover the active layer 564. And a part of the active layer 564 facing the gate electrode 562 is a channel region 564c. Impurity doped drain region 564d and source region 564c are disposed on each side of channel region 564c. The drain region 564d of the active layer 564 is connected to the data line and the data line also functions as the drain electrode 566 through a contact hole formed in the intermediate insulating layer 568 covering the gate electrode 562 . Further, the insulating layer 570 is arranged to cover the data line and the drain electrode 566. The nanostructure according to one embodiment of forming the pixel electrode 552 is disposed on the insulating layer 570. The pixel electrode 552 is connected to the source region 564s of the active layer 564 through the contact hole. The first alignment layer 572 may be disposed on the pixel electrode.

The nanostructure according to one embodiment can be applied to a liquid crystal display device based on a bottom gate type thin film transistor as well as a top gate thin film transistor based liquid crystal display device shown in FIG. In the bottom gate type thin film transistor, the gate electrode is disposed under the active layer, unlike the top gate type thin film transistor.

The nanostructure according to one embodiment is suitable for a display electrode in a PDP, and is electrically and optically stable at a high temperature such as 300 ° C.

FIG. 14 schematically shows a structure of a plasma display panel (PDP), which is one of flat panel display panels including a nanostructure according to one embodiment.

The PDP 606 includes a lower transparent substrate 608, a lower insulating layer 610 formed on the lower transparent substrate 608, an address electrode 612 formed on the lower insulating layer 608, A lower dielectric layer 614 formed on the address electrodes 612 and the lower insulating layer 610, insulating walls 616 defining discharge cells 618, black (not shown) disposed on the insulating walls 616, A phosphor layer 622, an upper transparent substrate 624, and an upper transparent substrate 624, which are formed on the side surfaces of the matrix layers 620, the black matrix layer 620 and the insulating wall 616 and on the lower insulating layer 608, A display electrode 626 disposed on the upper transparent substrate 624 at a right angle with respect to the electrode 612 and formed on a portion of the display electrode 626, An upper dielectric layer 630 formed on the display electrode 626 and the upper transparent substrate 624, And a protective layer (e.g., MgO) 632 formed on the upper dielectric layer 630.

The display electrodes are formed and patterned by the nanostructure according to one embodiment.

The nanostructure according to one embodiment may be used for a photovoltaic cell, an electroluminescence device, and the like.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Manufacturing example  One: Polyvinylpyrrolidone ( PVP ) The coating film  Silver formed on the surface Nanowire  Produce

² g of PtCl ₂ were dissolved in 0.5 ml of ethylene glycol, which was added to 5 ml of ethylene glycol and heated to about 160 캜.

5 ml of an ethylene glycol solution of silver nitrate (AgNO ₃ ) (0.05 g, Aldrich, 99 +%) and 5 ml of an ethylene glycol solution of polyvinylpyrrolidone (0.2 g, weight average molecular weight: 40,000) were added to the reaction mixture. The reaction mixture was heated at 160 < 0 > C for about 60 minutes.

The reaction product was cooled to room temperature (25 캜), added with acetone, diluted about 10 times and centrifuged at about 2000 rpm for about 20 minutes to prepare a silver nanowire having a PVP coating film on its surface.

Table 1 below shows the etchant used in Examples 1-11, the etching time, and the pH conditions of the etchant.

Etching solution, etching
Time and pH An etching solution Etching time The pH of the etchant Example 1 15 wt% NaOCl + Deionized Water 2.5 min 6 Example 2 15 wt% NaOCl + 1M CH3COOH (20 vol%) + deionized water 3min 4 Example 3 15 wt% NaOCl + 1M NaOH (10 vol%) + deionized water 2.5 min 11 Example 4 2.0 wt% NaOCl + 1M CH3COOH (20 vol%) + deionized water 3min 5.3 Example 5 2.5 wt% NaOCl + 1M CH3COOH (20 vol%) + deionized water 3min 5.4 Example 6 3.33 wt% NaOCl + 1M CH3COOH (20 vol%) + deionized water 30sec 5.6 Example 7 5.0 wt% NaOCl + 1 M CH3COOH (20 vol%) + deionized water 30sec 5.8 Example 8 2.5 wt% NaOCl + 1M CH3COOH (20 vol%) + deionized water 30sec 5.4 Example 9 15 wt% NaOCl + 1M NaOH (10 vol%) + deionized water 2.5 min 13 Example 10 15 wt% NaOCl + 1M NaOH (10 vol%) + deionized water 2.5 min 12 Example 11 15 wt% NaOCl + 0.1 M NaOH (10 vol%) + deionized water 7min 11

Example  1: Preparation of nanostructure

A silver nanowire aqueous dispersion was prepared by mixing silver nanowires formed on the surface of the PVP coating film and deionized water.

Silver nanowire aqueous dispersion was coated on top of the silicon substrate and dried to form a silver nanowire layer on the substrate.

A composition for forming a matrix was coated on the silver nanowire layer to form a matrix (overcoat film) having a thickness of about 100 nm on the silver nanowire-containing film to prepare a conductive film. The composition for forming a matrix was obtained by mixing 1 g of urethane acrylate and 9 g of a mixed solvent of diacetone alcohol and isopropyl alcohol (1: 1 volume ratio).

A photoresist film is formed on the first region of the conductive film and patterned to form a mask pattern on the first region of the conductive film. Using this mask pattern as a mask, the second region of the conductive film on which no mask is disposed is dipped in the etching solution for about 8 minutes to partially etch the silver nanowire existing in the second region of the conductive film by using the etching solution Lt; / RTI > for about 2.5 minutes.

As the etching solution, an etching solution containing sodium hypochlorite and deionized water was used. Here, the pH of the etching solution was about 6, and the content of sodium hypochlorite in the etching solution was about 15% by weight.

The resulting etched product was washed with deionized water and dried to produce a nanostructure.

Example  2: Preparation of nanostructure

A nanostructure was prepared in the same manner as in Example 1 except that a solution prepared by adding 1 M acetic acid to the etching solution of Example 1 was used as the etching solution and the etching time was about 3 minutes. The content of 1 M acetic acid in the etching solution was 20% by volume, and the pH of the etching solution was about 4.

Example  3: Preparation of nanostructure

A nanostructure was produced in the same manner as in Example 1 except that 1 M sodium hydroxide was added to the etching solution of Example 1 as an etching solution and the etching time was about 2.5 minutes. The content of sodium hydroxide in the etching solution was 10% by volume, and the pH of the etching solution was about 11.

Example  4: Preparation of nanostructure

A silver nanowire aqueous dispersion was prepared by mixing silver nanowires formed on the surface of the PVP coating film and deionized water.

Silver nanowire aqueous dispersion was coated on top of the silicon substrate and dried to form a silver nanowire layer on the substrate.

A photoresist film is formed on the first region of the silver nanowire layer and patterned to form a mask pattern on the first region of the nanowire layer. Using this mask pattern as a mask, a second region of the nanowire layer where no mask is disposed is dipped in an etchant for about 8 minutes to partially etch silver nanowires existing in the second region of the nanowire layer For about 3 minutes. Here, a solution prepared by adding 1 M CH ₃ COOH solution to a solution containing sodium hypochlorite and deionized water was used as an etchant, and the pH of the etchant was about 5.3. In the etching solution, the content of 1 M acetic acid in the etching solution was 20 vol%, and the content of hypochlorous acid was about 2.0 wt%.

The resultant was washed with deionized water and dried to prepare a nanostructure.

Example  5: Preparation of nanostructure

The procedure of Example 4 was repeated except that a solution containing about 2.5% by weight of sodium hypochlorite (NaOCl) was prepared using the etching solution of Example 4 and the solution was used as an etching solution, . The pH of the etchant was about 5.4.

Example  6: Preparation of nanostructures

A solution containing about 3.33% by weight sodium hypochlorite was prepared using the etchant of Example 4, and the solution was used as an etchant and the etching time was changed to about 30 seconds. In the same manner as in Example 4 Thus preparing a nanostructure. The pH of the etchant was about 5.6.

Example  7: Fabrication of nanostructures

The same procedure as in Example 4 was carried out except that a solution containing about 5.0 wt% sodium hypochlorite was prepared by using the etchant of Example 4, and this solution was used as an etchant and the etching time was about 30 seconds Thus preparing a nanostructure. The pH of the etchant was about 5.8.

Example  8: Fabrication of nanostructures

A solution containing about 2.5% by weight of sodium hypochlorite (NaOCl) was prepared using the etchant of Example 4, the same solution as in Example 4 except that this solution was used as an etchant and the etch time was changed to about 30 seconds To prepare a nanostructure. The pH of the etchant was about 5.4.

Example  9: Preparation of nanostructure

A nanostructure was prepared in the same manner as in Example 3 except that the pH of the etching solution was changed to about 13.

Example  10: Fabrication of nanostructures

A nanostructure was prepared in the same manner as in Example 3 except that the pH of the etching solution was changed to about 12.

Example  11: Fabrication of nanostructures

A nanostructure was prepared in the same manner as in Example 1 except that a solution prepared by adding sodium hypochlorite as an etchant and 0.1 M sodium hydroxide to deionized water was used and the etching time was changed to about 7 minutes . The sodium hypochlorite content in the etchant was about 15 wt%, the sodium hydroxide content was 10 vol%, and the etchant had a pH of about 11.

Table 2 shows etching conditions and etching time conditions in Comparative Example 1-4.

division Etching solution Etching time Comparative Example 1 91.8 wt% H3PO4 + 8.2 wt% HNO3 7min Comparative Example 2 67wt% H3PO4 + 6.0wt% HNO3 + 10wt% CH3COOH + Deionized Water (Balance) + additives 2 min Comparative Example 3 67wt% H3PO4 + 6.0wt% HNO3 + 10wt% CH3COOH + Deionized Water (Balance) + additives 3min Comparative Example 4 67wt% H3PO4 + 6.0wt% HNO3 + 10wt% CH3COOH + Deionized water (Balance) + additives 20 sec

Comparative Example  1: Preparation of nanostructure

A nanostructure was prepared in the same manner as in Example 1, except that a mixture of 91.8% by weight of H ₃ PO ₄ and 8.2% by weight of HNO ₃ was used as an etching solution and etching was performed for 7 minutes.

Comparative Example  2: Preparation of nanostructure

Except that PMA-17A (Soulbrain Co., phosphoric acid 67 weight%, nitric acid 6.0 weight, acetic acid 10 weight%, additive + deionized water (balance)) was used as the etching solution and the etching time was changed to 2 minutes , The same procedure as in Comparative Example 1 was carried out to prepare a nanostructure.

Comparative Example  3: Preparation of nanostructure

The nanostructure was prepared in the same manner as in Comparative Example 2 except that the etching time was changed to about 3 minutes.

Comparative Example  4: Preparation of nanostructure

The nanostructure was prepared in the same manner as in Comparative Example 2 except that the etching time was changed to about 20 seconds.

Evaluation example  1: Optical microscope, electron microscope and transmission electron microscopy

1) Example 3 and Comparative Example 1-2

The nanostructures prepared according to Example 3 and Comparative Example 1-2 were subjected to optical microscopy and electron microscope analysis. S-5500 (Hitachi) was used for the electron microscope analysis and Titan cubed 60-300 of FEI was used as the analyzer for the transmission electron microscopic analysis.

The optical microscope photographs of the nanostructures prepared in Example 3 are as shown in FIG. 5c, and the micrographs of the nanostructures prepared in Example 3 are as shown in FIG. 5b and FIG. 5e. 6, and the results of the optical microscope and the electron microscope analysis of the nanostructure produced in accordance with Comparative Example 2 are shown in FIGS. 7A, 7B, and 7B. FIG. 7c. FIG. 7B is an enlarged view of the circle area in FIG. 7A, and FIG. 7C is an enlarged circle area in FIG.

In Figs. 5D, 6 and 7B, the left region represents the etched region and the right region represents the non-etched region.

As shown in Fig. 6, in the nanostructure produced according to Comparative Example 1, silver nanowires were hardly observed even in the region where etching was performed using nitric acid and phosphoric acid as an etchant.

As can be seen from FIGS. 7A to 7C, the nanostructure produced according to Comparative Example 2 has a considerable number of silver nanowires in the etched region using a mixture of nitric acid, phosphoric acid, and acetic acid as an etchant, And the length thereof were very different from those of Example 3.

On the other hand, the nanostructure produced according to Example 3 has a problem in that it is difficult to distinguish the etched region from the non-etched region as shown in FIGS. 5C to 5E, the diameter of the silver nanowires in the etched region is uniform, And it was found that it shows the insulation characteristics between patterns. And that the break length of the second nanowire is relatively uniform. The uniformity of the diameter of the nanowire is maintained by the reaction of sodium hypochlorite and silver nanoparticles in the alkali solution and polyvinylpyrrolidone present on the surface of the nanowire uniformly in the chain of the polyvinylpyrrolidone It is because it cuts out.

2) Measurement of mean diameter and average length of nanowires

Electron microscopic analysis of the nanostructures prepared according to Example 3 and Comparative Example 1-2 was carried out. S-5500 (Hitachi) was used for electron microscope analysis.

The average length and average diameter deviation of the first nanowire and the second nanowire can be calculated by using the length and diameter of the first nanowire and the second nanowire through electron microscope analysis and calculating the average length and average diameter of the first nanowire and the second nanowire Respectively. And the difference between the average diameter of the first nanowire and the second nanowire and the average length of the first nanowire and the second nanowire are calculated according to the following equations (5) and (6), respectively.

[Formula 5]

Average diameter difference = {average diameter of first nanowire (AgNW1) - average diameter of second nanowire (AgNW2)} / average diameter of first nanowire (AgNW1)} X100

[Formula 6]

Average length difference = {average length of first nanowire (AgNW1) - average length of second nanowire (AgNW2)} / average length of first nanowire (AgNW1)} X100

division Mean diameter difference (%) Average
Length difference (%) Example 3 4.5 9 Comparative Example 1 7 15 Comparative Example 2 9 20

As shown in Table 3, the nanostructure produced according to Example 3 had a difference in average diameter between the first nanowire and the second nanowire of 5% or less and an average length difference between the first nanowire and the second nanowire The average diameter difference between the first nanowire and the second nanowire is greater than 5% and the average length difference between the first nanowire and the second nanowire is within 10%, while in the nanostructure produced according to Comparative Example 1-2, Was in the range exceeding 10%.

The average diameter difference and the average length difference of the first nanowire and the second nanowire in the nanostructure fabricated according to Example 11 and Comparative Example 3-4 were determined and are shown in Table 4 below.

division Mean diameter difference (%) Average length difference (%)
Example 11 4.3 8 Comparative Example 3 9 15 Comparative Example 4 11 20

As shown in Table 4, the nanostructure produced according to Example 11 had a difference in average diameter between the first nanowire and the second nanowire of 5% or less and an average length difference between the first nanowire and the second nanowire The average diameter difference between the first nanowire and the second nanowire is greater than 5% and the average length difference between the first nanowire and the second nanowire is within 10%, while in the nanostructure produced according to Comparative Examples 3 and 4, Was in the range exceeding 10%.

3) Example 1, Example 2, Example 11 and Comparative Example 3-4

The nanostructures prepared according to Example 1, Example 2, Example 11, and Comparative Example 3-4 were analyzed using a scanning electron microscope.

S-5500 (Hitachi) was used for electron microscope analysis.

15A to 15E show electron micrographs of etched regions in the nanostructures prepared according to Example 1, Example 2, Example 11, Comparative Example 3, and Comparative Example 4, respectively.

15A to 15C, Example 1 using a solution containing hypochlorous acid as an etchant, Example 2 using a mixture of hypochlorous acid and acetic acid as an etchant, and Example 1 in which sodium hydroxide was further added to the etchant of Example 1 The nanostructures prepared according to Example 11 showed that the silver nanowires were relatively homogeneously present in the etched regions.

On the other hand, referring to FIG. 15D to FIG. 15E, the diameter and the length of the silver nanowire in the nanostructure produced according to Comparative Examples 3 and 4, in which PMA-17A was used as the etchant and the etching time was 3 minutes and 20 seconds, 1, 2, and 11, respectively.

Evaluation example  2: Transmission electron microscopy analysis

1) Examples 4-7

FIGS. 10A to 10D are transmission electron micrographs of nanowires prepared according to Examples 4-7. FIG. As the transmission electron microscope, Titan cubed 60-300 of FEI company was used. In Examples 4, 5, 6 and 7, the contents of sodium hypochlorite were 2.0 wt%, 2.5 wt%, 3.33 wt% and 5.0 wt%, respectively.

Referring to this, it can be seen that the shape of the etched nanowires varies depending on the content of sodium hypochlorite used in the etching. As described above, when the concentration of sodium hypochlorite is appropriately controlled, not only the shape of the nanowire to be etched is changed but also the etching can proceed in a shorter time, and it is found that mass production is easy to apply.

2) Example 3

Transmission electron microscopic analysis results of the nanostructures prepared according to Example 3 are shown in FIGS. 5A and 5B, and optical microscope photographs are shown in FIG. 5C. FIG. 5A shows a transmission electron microscope photograph of the initial etching stage in Example 3, and FIG. 5B shows a transmission electron microscope photograph of the etching state. And FIG. 5C shows an optical microscope photograph of a partially etched region and a mask region performed according to Example 3, FIGS. 5D and 5E are electron micrographs, FIG. 5E shows a circle region in FIG. FIG.

3) Example 6 and Example 8

Transmission electron micrographs of the nanowires prepared according to Examples 6 and 8 are shown in FIGS. 11B and 11C. A transmission electron micrograph of the nanowire before etching is shown in FIG. 11A.

As a result, it was found that the pattern of PVP etching was different depending on the concentration of NaOCl. And pH control changes the removal of PVP, which changes the length of etched silver nanowires.

Evaluation example  3: Light transmittance  And Hayes's  Measure

1) Example 3, Comparative Example 1-2

The light transmittance, haze and resistance of the nanostructures prepared according to Example 3 and Comparative Example 1-2 were measured. Here, light transmittance and haze were measured using a BYK Gardner Haze-Gard Plus. The surface resistivity was measured using a Fluke 175 True RMS Multometer.

The measurement results are shown in Table 5 below. In Table 3, the difference in light transmittance represents the light transmittance before and after the etching of the nanostructure, or the light transmittance difference between the conductive region and the non-conductive region. And the haze difference represents the haze difference before etching in the nanostructure and the haze difference after etching or the haze difference between the conductive region and the nonconductive region.

division Light transmittance (%) Haze (%) ΔT (light transmittance difference) (%) ΔH
(Difference in Haze) (%) Before etching 90.6 1.04 Example 3 90.7 0.9 0.1 0.14 Comparative Example 1 92.4 0.6 1.8 0.44 Comparative Example 2 92.1 0.55 1.5 0.49

As can be seen from the above Table 5, the nanostructure prepared according to Example 3 has a smaller difference in transmittance and haze than the nanostructure prepared according to Comparative Example 1 and Comparative Example 2, and thus the visibility problem can be solved. From these results, it was confirmed that the case of performing etching according to the third embodiment solves the problem of visibility by having the diameter of the nanowire not changed greatly and being partially disconnected. It is considered that the scattering around the silver nanowire depends on the change of the diameter of the silver nanowire based on the theoretical formula for Rayleigh scatterning in Table 5 above. Since the difference in transmittance and haze is small, the problem of pattern inter-view after silver nanowire patterning can be largely solved. It has been found that the reliability of the insulating portion is improved by forming an insulator of silver chloride after etching using a chlorine-based etching agent such as sodium hypochlorite.

2) Example  One, Example  2, Example  11 and Comparative Example  3-4

The light transmittance, haze and resistance of the nanostructures prepared according to Example 1, Example 2, Example 11, and Comparative Example 3-4 were measured. Here, light transmittance and haze were measured using BYK Gardner Haze-Gard Plus. The surface resistivity was measured using a Fluke 175 True RMS Multimeter.

The measurement results are shown in Table 4 below. In Table 6, the difference in light transmittance represents the light transmittance before and after etching of the nanostructure, or the light transmittance difference between the conductive region and the non-conductive region. And the haze difference represents the haze difference before etching in the nanostructure and the haze difference after etching or the haze difference between the conductive region and the nonconductive region.

division Visibility Δ T (%) H (%)
Example 1 0.04 0.039 Example 2 0.06 0.07 Example 11 0.08 0.016 Comparative Example 3
1.54 0.696
Comparative Example 4 0.98 0.429

In Table 6, ΔT represents the difference in light transmittance before and after etching, and ΔH represents the difference in haze before and after etching.

From Table 6, it can be seen that the nanostructures prepared according to Examples 1, 2, and 11 are different from the nanostructures prepared according to Comparative Examples 3 and 4 in that the difference in transmittance and haze is reduced and the visibility problem is solved.

Evaluation example  4: Measurement of surface resistance

The surface resistances of the nanostructures prepared according to Example 1 and Comparative Example 1 were measured. Here, the surface resistance was measured using a Fluke 175 True RMS Multometer, and the surface resistance difference represents the surface resistance of the etched region and the non-etched region, or the difference in surface resistance before and after etching.

The surface resistance of the nanostructure prepared according to Comparative Example 1 increased to 30 Ω / □ before etching and to 154.5 Ω / □ after etching.

On the contrary, the nanostructures prepared according to Example 1 showed a difference in surface resistance before and after etching compared with the nanostructures prepared according to Comparative Example 1.

Evaluation example  5: Photoelectron spectroscopy (X- photoelectron spectroscopy ) And HAADF -STEM (a high angle annular dark field scanning transmission electron microscope ) analysis

XPS spectroscopy was performed on the nanostructures prepared according to Example 1 using Qunatum 2000 (Physical Electronics) equipment. XPS analysis was performed using Qunatum 2000 (Physical Electronics) equipment.

The XPS spectroscopic test results are shown in Figs. 8A to 8F.

Referring to FIG. 8B, it can be seen that the chemical state of the surface-coated polymer of the silver nanowire has hardly changed after the etching.

As shown in Figs. 8A and 8E, it was confirmed that silver chloride (AgCl) and sodium chloride (NaCl) were observed in the region where the silver component was detected. Sodium hypochlorite has been found to react with silver nanowires to form insulators such as silver chloride and sodium chloride. Sodium chloride could be removed through a sufficient cleaning process.

The results of HAADF-STEM analysis are as shown in Figs. 9A to 9C. As a result, the presence of silver and chlorine (Cl) could be confirmed.

Evaluation example  6: aging test

The wiring reliability of the silver nanowires fabricated according to the nanostructure fabricated in accordance with Example 5-6 was evaluated and the aging test was performed.

In the following Table 6, the resistance change was evaluated by examining the resistance change at 85 ° C and the relative humidity of 85%, and the reliability of the silver nanowire was evaluated by examining the resistance change. The results are shown in Table 7 same.

division Change in resistance (R) (%) 10 day 18 day Example 5 5.1 10.4 Example 6 4.9 -

As shown in Table 7, it was found that the silver nanowires prepared according to Example 5-6 had excellent wiring reliability.

Evaluation example  7: Optical microstructural change test

The change in optical microstructure according to the elapse of etching time in the preparation of the nanostructure according to Example 2 was examined using an electron scanning microscope, and the light transmittance, haze and resistance of the nanostructure were measured in Example 2. Here, light transmittance and haze were measured using BYK Gardner Haze-Gard Plus. The surface resistivity was measured using a Fluke 175 True RMS Multimeter.

The results of electron microscope analysis are shown in Figs. 16A to 16E. FIGS. 16A to 16D are electron micrographs each showing an etching time of about 1 minute, about 2 minutes, about 3 minutes, about 4 minutes, and about 5 minutes, respectively.

In addition, the permeability and the haze difference of the etched region and the non-etched region according to the etching time in the nanostructure produced according to Example 2 were investigated and shown in FIG. In Fig. 17, an etched area-non-etched area represents a difference in transparency or haze between an etched area and a non-etched area.

With reference to this, when the etching according to the second embodiment was applied and further etching was performed starting from about 1 minute to be insulated, the etched shape of the AgNW did not change much after 5 minutes and the etching. Therefore, the light transmittance and the haze difference did not vary greatly.

In the case of using the conventional etching solution, when the etchant is etched, the haze difference becomes larger and visibility problem occurs. However, when the etching solution of pH 4 is used, since the silver nanowire does not change, the haze does not change much and the visibility problem does not occur. An insulating film is formed on the surface of the nanowire, so that the durability of the transparent electrode made of silver nanowires can be improved without being influenced by the etching solution.

Evaluation example  8: Reliability Analysis

The nanostructures prepared in accordance with Example 1 and Comparative Example 4 were etched and packaged in the device of FIG. 18A, respectively, and reliability analysis was performed.

18A, reference numeral 180 denotes a glass substrate, reference numeral 181 denotes an optical clear adhesive (OCA), reference numeral 182 denotes a nanostructure produced according to Example 1 or a comparison Reference numeral 184 denotes a polyethylene terephthalate (PET) film, and reference numeral 183 denotes a metal wiring such as a silver wiring.

The above-described reliability analysis results are shown in Figs. 18B and 18C. In Fig. 18B, 50 占 퐉 and 200 占 퐉 indicate the case where the thickness of the nanostructure produced according to Example 1 is 50 占 퐉 and 200 占 퐉, respectively.

18C shows a case in which the nanostructure (thickness is 50 mu m) prepared in Example 1 ((50 mu m) and Comparative Example 4 (50 mu m) according to Example 1 and Comparative Example 4 is measured in a film state .

Referring to FIG. 18B, the nanostructure fabricated according to Example 1 showed a resistance change of 1% or less as a result of reliability experiment.

Referring to FIG. 18C, it can be seen that the reliability of the nanostructure fabricated according to Example 1 is lower than that of the nanostructure fabricated according to Comparative Example 4, since the change with time of resistance is small.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the exemplary embodiments or constructions. It will be apparent to those skilled in the art that various modifications and variations are possible in light of the above teachings will be. Accordingly, the scope of protection of the present invention should be determined by the appended claims.

10, 20: substrate 11: nanostructure
12a: conductive region 12b: non-conductive region
13, 23: first nanowire 14: second nanowire
15, 25: Matrix

Claims (33)

And includes a conductive region and a nonconductive region,
The conductive region containing at least one first nanowire,
Wherein the non-conductive region comprises at least one second nano-crystal region partially broken. The method according to claim 1,
Wherein the average diameter of the second nanowires is smaller than the average diameter of the first nanowires and the difference between the average diameter of the first nanowires and the average diameter of the second nanowires is less than 5% . The method according to claim 1,
Wherein an average length of the second nanowires is smaller than an average length of the first nanowires and a difference between an average length of the first nanowires and an average length of the second nanowires is within 10% Nanostructures. The method according to claim 1,
Wherein the difference in resistance between the non-conductive region and the conductive region is 10 ⁹ Ω / □ or more. The method according to claim 1,
And the second nanowire has an average diameter deviation of 5 to 10 nm. The method according to claim 1,
And the second nanowire has an average length deviation of 2 to 10 占 퐉. The method according to claim 1,
Wherein the second nanowire has an aspect ratio of 1 to 500. The method according to claim 1,
Wherein the aspect ratio of the second nanowire is 90% or more. The method according to claim 1,
Wherein an insulating film is formed on at least a part of the surface of the second nanowire. 10. The method of claim 9,
Wherein the insulating film comprises at least one selected from the group consisting of silver chloride (AgCl) and silver oxide. The method according to claim 1,
And a polymer membrane is formed on at least a part of surfaces of the first nanowire and the second nanowire. 12. The method of claim 11,
The polymer membrane may be formed of at least one selected from the group consisting of polyvinylpyrrolidone, polyacetylene, polypyrrole, polythiophene, polyaniline, polyfluorene, poly (3-alkylthiophene) And at least one selected from the group consisting of rhenium and polyparaphenylene vinylene. The method according to claim 1,
Wherein the second nanowire has an average diameter of 9.5 to 95 nm and an average length of 2.4 to 80 탆. The method according to claim 1,
Wherein the haze in the non-conductive region is smaller than the haze in the conductive region, and the haze in the non-conductive region and the haze difference in the conductive region is 0.2% or less. The method according to claim 1,
Wherein the first nanowires have an average diameter of 10 to 100 nm and an average length of 3 to 200 탆. The method according to claim 1,
And a second nanowire having a region having a very small average diameter as compared with an average diameter of the second nanowires. The method according to claim 1,
Wherein the non-conductive region further comprises an insulating portion between the plurality of second nanowires. The method according to claim 1,
Wherein the first nanowire and the second nanowire are made of at least one selected from the group consisting of Fe, Pt, Ni, Co, Al, Ag, Au, , Silicon (Si), germanium (Ge), cadmium sulfide (CdS), selenium sulfide (CdSe), cadmium telluride (CdTe), zinc sulfide (ZnS), zinc selenide (ZnSe), zinc telluride (GaN), gallium arsenide (GaP), gallium arsenide (GaAs), gallium arsenide (GaSb), aluminum nitride (AlN), aluminum phosphate (AlP), aluminum arsenide (AlAs), aluminum antimony the (InP), indium arsenide (InAs), indium antimony (InSb), silicon carbide (SiC), iron platinum (FePt), iron oxide (Fe ₂ O ₃₎ and iron oxide is selected from the group consisting of (Fe ₃ O ₄₎ One or more nanostructures. The method according to claim 1,
Wherein the transmittance of the non-conductive region is larger than the transmittance of the conductive region, and the difference between the transmittance of the non-conductive region and the transmittance of the conductive region is 0.1% or less. The method according to claim 1,
A nanostructure further comprising a matrix. 21. The method of claim 20,
Wherein the matrix is at least one polymer selected from the group consisting of a polyurethane resin, a polyester resin, an acrylic resin, a polyether resin, a cellulose resin, a polyvinyl alcohol resin, an epoxy resin, polyvinyl pyrrolidone, a polystyrene resin and polyethylene glycol ≪ / RTI > A first step of forming a first nanowire layer comprising at least one first nanowire;
A second step of coating a material for a matrix on the first nanowire layer to produce a conductive film including the first nanowire and the matrix; And
And a third step of etching a part of the conductive film in contact with an etching solution containing at least one selected from among alkali metal hypochlorous acid and alkaline earth metal hypochlorous acid and in a weakly acidic condition or an alkaline condition, A method of manufacturing a nanostructure for manufacturing a nanostructure of one term. 23. The method of claim 22,
A photoresist film is formed on the conductive film before the third step,
Wherein a portion of the conductive film is in contact with the etching solution using the photoresist film as an etching mask. 23. The method of claim 22,
Wherein at least one selected from alkali metal hypochlorous acid and alkaline earth metal hypochlorous acid is at least one selected from the group consisting of sodium hypochlorite, potassium hypochlorite, lithium hypochlorite, magnesium hypochlorite and calcium hypochlorite. 23. The method of claim 22,
Wherein the pH is 3 to 6 under the weakly acidic condition and the pH is 10 or more under the alkaline condition. 23. The method of claim 22,
Wherein the etchant comprises at least one selected from the group consisting of a solvent, a pH adjuster, a reaction retarder, an oxidizer, and an etchant. 23. The method of claim 22,
Wherein the content of at least one selected from alkali metal hypochlorous acid and alkaline earth metal hypochlorous acid in the etching solution is 1 to 30% by weight. 23. The method of claim 22,
And the step of contacting the conductive film with the etchant is 10 seconds to 10 minutes. 27. The method of claim 26,
Wherein the oxidizing agent is at least one selected from the group consisting of peroxide, persulfide, peroxo compound, metal oxide salt, organic oxidizing agent and gas oxidizing agent. 27. The method of claim 26,
Wherein the etching agent is at least one selected from the group consisting of nitric acid, phosphoric acid, acetic acid, sodium nitrate (NaNO ₃ ) and halides. 23. The method of claim 22,
Wherein a conductive polymer film is formed on at least a part of the surface of the first nanowire. 22. A panel unit comprising a nanostructure according to any one of claims 1 to 21. 33. The method of claim 32,
Wherein the panel unit is a flat panel display (FPD), a touch screen panel (TSP), a flexible display, or a foldable display.

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