KR101894982B1 - Method for fabricating nanoparticle clusters - Google Patents

Abstract

The present invention relates to a method of manufacturing a nanoparticle assembly, and more particularly, to a method of manufacturing a nanoparticle assembly by forming a plurality of guide patterns on a substrate, arranging sublimable liquid crystal supramolecules between the guide patterns, heating the sublimable liquid crystal supramolecules, Forming a liquid crystal thin film by cooling it with a smectic phase, applying a dispersion of nanoparticles on the formed liquid crystal thin film, and annealing at a liquid crystal phase temperature.
The nanoparticle assembly according to the manufacturing method of the present invention can be periodically arranged using the defect structure of the liquid crystal thin film and the liquid crystal thin film serving as a template is removed by sublimation so that only a nanoparticle assembly can be obtained without a liquid crystal thin film , The arrangement and spacing of the nanoparticle assemblies can be easily controlled. Therefore, the nanoparticle assembly produced by the present invention can be applied not only to nano-electronic devices and optical devices including semiconductor light emitting devices, but also to environment-related materials. In particular, in the case of semiconductor nanoparticles, And can be used as a new optical device material.

Description

[0001] METHOD FOR FABRICATING NANOPARTICLE CLUSTERS [0002]

The present invention relates to a method of manufacturing a nanoparticle assembly, and more particularly, to a method of manufacturing a nanoparticle assembly by forming a plurality of guide patterns on a substrate, arranging sublimable liquid crystal supramolecules between the guide patterns, heating the sublimable liquid crystal supramolecules, Forming a liquid crystal thin film by cooling it with a smectic phase, applying a dispersion of nanoparticles on the formed liquid crystal thin film, and annealing at a liquid crystal phase temperature.

One of the useful ways to fabricate functional nanostructures that exhibit specific structural and electro-optical properties is self-assembly, which finds the thermodynamic stability of the basic units that make up the structure and forms a spontaneously stable structure. It has attracted attention in the field of science and technology.

Basic units suitable for such self-assembly methods include various molecular units such as small molecular sieve units in angstroms, biomaterials such as DNA and proteins, and nanoparticles of colloid. Among these monomers, nano- or micro-sized organic / inorganic particles can uniformly produce nanoparticles as small as nanoparticles small enough to represent the resolution limit of conventional optical lithography techniques, Optical properties and so on, the nanoparticles and the microstructures of the nanoparticles have attracted considerable attention as a unit material. It is important to maximize the properties of these nanoparticles' self-assemblies and, above all, for an array of uniformly aligned self-assemblies over a large area for practical applications.

Various techniques such as drying oil-emulsion template, electrostatic assembly, chemical vapor deposition, and template assisted assembly have been developed for this purpose. Although it has been reported by a number of researchers at home and abroad, it has a disadvantage in that a complicated process using expensive equipment is required to reach uniform arrangement of nanoparticle assemblies over a large area.

The present inventors have made intensive efforts to arrange nanoparticle assemblies uniformly on a large area without complicated processes using existing expensive equipments. As a result, they have found that supercritical liquid crystal supramolecules are arranged and heated at above isotropic temperature of liquid crystal supramolecules, (TFCD), and it is possible to control the size of the assembly according to the concentration of the nanoparticle dispersion, and it is possible to control the pitch of the guide pattern The arrangement of the nanoparticle assemblies and the spacing between the assemblies can be adjusted according to the height, and the present invention has been completed.

It is an object of the present invention to provide a method of manufacturing a nanoparticle assembly.

It is another object of the present invention to provide a method of controlling the arrangement of nanoparticle assemblies.

It is another object of the present invention to provide a method for adjusting the distance between nanoparticle assemblies.

According to an aspect of the present invention, there is provided a method of manufacturing a semiconductor device, including: forming a plurality of guide patterns on a substrate; Disposing sublimable liquid crystal supramolecules between the plurality of guide patterns; Heating the sublimable liquid crystalline supramolecule and cooling it to a smectic phase to form a liquid crystal thin film; Applying a dispersion of nanoparticles on the formed liquid crystal thin film, and annealing the nanoparticle dispersion at a liquid crystal phase temperature.

The present invention also provides a method of adjusting the array of nanoparticle assemblies by adjusting the guide pattern pitch of the nanoparticle assembly produced by the method.

The present invention also provides a method for adjusting the distance between nanoparticle assemblies by adjusting the height of a guide pattern of the nanoparticle assembly produced by the method.

The nanoparticle assembly according to the manufacturing method of the present invention can be periodically arranged using the defect structure of the liquid crystal thin film and the liquid crystal thin film serving as a template is removed by sublimation so that only a nanoparticle assembly can be obtained without a liquid crystal thin film , The arrangement and spacing of the nanoparticle assemblies can be easily controlled. Therefore, the nanoparticle assembly produced by the present invention can be applied not only to nano-electronic devices and optical devices including semiconductor light emitting devices, but also to environment-related materials. In particular, in the case of semiconductor nanocomposites, And can be used as a new optical device material.

FIG. 1 illustrates a method of fabricating a nanoparticle assembly in accordance with one embodiment.
FIG. 2 is an electron micrograph of supersaturated liquid crystalline supramolecules according to one embodiment and the heating time after the arrangement.
FIG. 3 is an electron micrograph of an F-SiO ₂ nanoparticle assembly according to an embodiment of the present invention. FIG.
FIG. 4 illustrates a polarizing microscope image according to an annealing treatment time of an F-SiO ₂ nanoparticle assembly according to an embodiment.
FIG. 5 is an electron microscope image of the concentration of the F-SiO ₂ nanoparticle dispersion according to one embodiment.
FIG. 6 illustrates an F-SiO ₂ nanoparticle assembly and an electron microscope image produced on a PDMS substrate according to one embodiment.
7 illustrates a polarization microscope image of a quantum dot nanoparticle assembly according to one embodiment.
FIG. 8 and FIG. 9 are a schematic view, an electron microscope and a polarizing microscope image of the guide pattern pitch (interval) of the F-SiO ₂ nanoparticle assembly according to an embodiment.
10 and 11 are a schematic view, an electron microscope and a polarized microscope image of the guide pattern height of the F-SiO ₂ nanoparticle assembly according to an embodiment.

The present invention can be all accomplished by the following description. It is to be understood that the following description is only illustrative of preferred embodiments of the invention, but the invention is not necessarily limited thereto. It is to be understood that the accompanying drawings are included to provide a further understanding of the invention and are not to be construed as limiting the present invention. The details of the individual components may be properly understood by reference to the following detailed description of the related description.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly used in the art.

According to one aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: (1) forming a plurality of guide patterns on a substrate; (2) disposing sublimable liquid crystal supramolecules between the plurality of guide patterns; (3) heating the sublimable liquid crystalline supramolecules and then cooling them into a smectic phase to form a liquid crystal thin film; And (4) applying a dispersion of nanoparticles on the liquid crystal thin film thus formed, followed by annealing at a liquid crystal temperature.

(1) a step of forming a plurality of guide patterns on a substrate will be described in detail in the method of manufacturing the nanoparticle assembly of the present invention.

1 (a), a plurality of mutually spaced guide patterns are formed on a substrate, and liquid crystal supramolecules, which will be described later, are disposed between the guide patterns, The guide patterns may be formed to be spaced apart from each other by a predetermined distance so that liquid crystal supramolecules may be disposed therebetween.

The method of forming the guide pattern is not particularly limited and can be formed by methods known in the art and can be formed by, for example, photolithography, three-dimensional printing, or scratching.

The distance (pitch) and height between the plurality of guide patterns can be adjusted according to the arrangement, size, spacing, and the like of the nanoparticle assembly to be formed. This will be described later in detail. The interval (pitch) is preferably 3 to 100 占 퐉, more preferably 3 to 50 占 퐉, the height is preferably 3 to 25 占 퐉, and more preferably 3 to 10 占 퐉, no.

The width of the guide pattern is preferably 3 to 50 탆, but is not limited thereto. The width of the guide pattern also affects the arrangement of the nanoparticle assemblies so that the spacing between the nanoparticle assembly arrays can be adjusted by adjusting the width of the guide pattern.

The guide patterns can be formed to be parallel to each other, but are not limited thereto, and can be appropriately selected according to the arrangement to be implemented of the nanoparticle assembly.

In the present invention, the substrate serves as a substrate on which a liquid crystal thin film is formed. The material is not limited as long as it does not cause deformation at a heating temperature. Examples of the material include plastic, glass, metal, metal oxide, And the like.

The plastic substrate is made of polyethylene terephthalate (PET), polyethylene sulfone (PES), polyethylene naphthalate (PEN), polycarbonate (PC), polymethylmethacrylate (PMMA), polystyrene (PS), polyimide (EVA), amorphous polyethylene terephthalate (APET), polypropylene terephthalate (PPT), polyethylene terephthalate glycerol (PETG), polyvinyl chloride (PVC), polyvinylpyrrolidone (PVP) ), Polycyclohexylenedimethylene terephthalate (PCTG), modified triacetyl cellulose (TAC), cycloolefin polymer (COP), cycloolefin copolymer (COC), dicyclopentadiene polymer (DCPD), cyclopentadiene polymer Selected from the group consisting of CPD, polyarylate (PAR), polyetherimide (PEI), polydimethylsilonane (PDMS), silicone resin, fluororesin, modified epoxy resin and FRP (Fiber Reinforced plastic) Or more, but is not limited thereto.

Further, in the manufacturing method of the present invention, a liquid crystal thin film can be formed also on a flexible substrate, and the substrate can be a flexible substrate.

The present invention may further include the step of modifying the substrate so that its surface has a hydrophilic group after forming the below-described light pattern, that is, the step of arranging the sublimable liquid crystal supramolecules. In such a case, when the liquid crystal supramolecules are positioned at two different boundary conditions, substrate and air, the molecules are arranged in parallel near the surface of the substrate, and because of the nature of the molecules to be arranged vertically as they approach the air, thereby forming a curvature and a tangential orientation of the plate-like structure.

For example, the substrate may be coated with polyethyleneimine or polyethylene glycol (PEG), or a self-assembled monolayer may be formed of a silica material. Alternatively, the surface of the substrate may be modified to have a hydrophilic group, assembled monolayer, SAM).

The silica material is preferably octadecyltrimethoxysilane (OTS) or trichloroperfluorooctylsilane, but is not limited thereto.

The coating method is not particularly limited and includes, for example, a slit coating method, a knife coating method, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a bar coating method, a roll coating method, Method, a spray coating method, or the like can be used.

Further, the method may further include a step of pretreating the substrate with a corona discharge treatment, a plasma treatment, or the like, before the substrate is modified so that the surface thereof has a hydrophilic group, if necessary. In such a case, the hydrophilization treatment of the substrate surface is easier.

(2) The step of arranging the sublimable liquid crystal supramolecules between the plurality of guide patterns will be described in detail in the manufacturing method of the nanoparticle assembly of the present invention.

The sublimable liquid crystal supramolecules of the present invention are liquid crystal supramolecules having sublimation properties and mean supramolecular liquid crystals vaporized on the liquid crystal.

As the sublimable liquid crystal supramolecules according to the present invention, rod-like liquid crystal molecules having two benzene rings in which both terminals are substituted with a fluorine (F) -based carbon chain and an ester group, respectively, can be used. Includes at least one compound represented by the following general formula (1), but is not limited thereto.

[Chemical Formula 1]

(Wherein R is an alkyl group having 1 to 4 carbon atoms).

By arranging the sublimable liquid crystal supramolecules between the plurality of guide patterns, it is possible to control the defect structure to be described later and the arrangement of the nanoparticle assemblies produced thereby.

A method of arranging sublimable liquid crystal supramolecules between a plurality of guide patterns is not particularly limited. For example, sublimable liquid crystal supramolecules are applied onto a substrate on which a guide pattern is formed, so that sublimable liquid crystal supramolecules are arranged between the guide patterns .

(3) a step of heating the sublimable liquid crystal supramolecules and then cooling them to a smectic phase to form a liquid crystal thin film will be described in detail.

Since the liquid crystal supramolecules are cooled in a smectic phase, the heating can be performed at an isotropic temperature or higher of liquid crystal supramolecules.

The isotropic temperature is preferably a temperature at which the liquid crystal supramolecule exhibits an isotropic liquid crystal phase, and is preferably 100 deg. C to 210 deg. C, and more preferably 154 deg. C to 210 deg.

Thereafter, the heated liquid crystal supramolecules are cooled in a smectic phase.

The heated liquid crystal supramolecules can be cooled in a smectic phase, more specifically in a smectic A phase. The temperature of the Smectic A phase is preferably 59 to 207 占 폚. In such a case, a liquid crystal thin film having a defect structure can be formed. Further, since the fluidity of the liquid crystal supramolecules is maximized at the time of transition from the liquid phase to the smectic A phase, the spreadability on the substrate is good and the liquid crystal film can be easily formed.

Liquid crystal supramolecules can basically be organized in a uniform cluster structure due to their inherent physical-chemical functionalities, and the assembly behavior at the molecular level is caused by reversible physical interactions, so that the most stable structure thermodynamically The liquid crystal supramolecules according to the present invention form a curvature in the molecular orientation at the interface between the substrate and the air and the tangential structure of the liquid crystal supramolecules is tangential ), And a defect structure (a toric focal conic domain, hereinafter referred to as TFCD) may be formed on the Smectic phase (see FIG. 2- (b)).

In particular, the sublimable liquid crystal supramolecules according to the present invention are arranged between a plurality of guide patterns, and a defect structure is located between the plurality of guide patterns. Therefore, the size of the defect structure, the interval between the defect structures, the arrangement of the defect structure, and the like can be adjusted according to the interval and height between the plurality of guide patterns.

The cooling rate is not particularly limited, and is preferably cooled at a rate of 5 to 20 占 폚 / min.

The size of the defect structure is not particularly limited. For example, the width may be 50 nm to 5 占 퐉, and the depth may be 10 nm to 1 占 퐉.

TFCD is unequally expressed in one TFCD due to the energy non-equilibrium state due to the layered structure bent around the TFCD when annealed at the liquid crystal phase. The molecules in the revealed stratified structure are vertically reoriented at the air interface, resulting in the recombination of the stratified structure. As a result, as shown in FIGS. 2- (c) and 2- (d), three-dimensional nano-sized semi-cylindrical structures around the TFCD concentrically form a hierarchical dome shape.

Using this sublimation and recombination phenomenon, TFCD can be adjusted in various ways.

(4) a step of applying a dispersion of nanoparticles on the liquid crystal thin film formed above and then performing an annealing treatment at a liquid crystal phase temperature will be described in detail.

The nanoparticle dispersion contains nanoparticles and a dispersion medium, and the nanoparticles contained in the dispersion form an aggregate according to the method of the present invention.

As the nanoparticles, nanoparticles known in the art can be used without limitation, and silica nanoparticles, metal nanoparticles, metal oxide nanoparticles, quantum dots and quantum rods can be used, and silica nanoparticles and quantum dots can be used. It is more preferable to use it. These may be used alone or in combination of two or more.

As the dispersion medium, nanoparticles can be dispersed, and it is easy to dry. If the liquid crystal thin film is not damaged, organic dispersion media, water, and the like known in the art can be used without limitation.

The method of applying the nanoparticle dispersion on the liquid crystal thin film is not particularly limited and examples thereof include a slit coating method, a knife coating method, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, A coating method, a wire bar coating method, a dip coating method, and a spray coating method.

When the nanoparticle dispersion is applied on the liquid crystal thin film, the nanoparticles collect on the recessed portion of the defect structure of the liquid crystal thin film.

The method of manufacturing a nanoparticle assembly of the present invention may further comprise the step of applying the dispersion of nanoparticles followed by drying the dispersion medium.

The drying method is not particularly limited, and can be, for example, natural drying, hot air drying, ultraviolet drying and the like.

Thereafter, the liquid crystal thin film coated with the nanoparticle dispersion liquid is annealed at a liquid crystal phase temperature.

As described above, since the liquid crystal thin film has a defect structure, when the nanoparticle dispersion is applied on the liquid crystal thin film having a defect structure as shown in FIG. 3- (a), the nanoparticles Gathered.

In this state, the liquid crystal supramolecules of the liquid crystal thin film are sublimated when the liquid crystal is annealed at the liquid crystal temperature. Part of the liquid crystal thin film where the nanoparticles are present prevents the particles from contacting the molecules of the defect structure surface with air, The peripheral portion of the defect structure is relatively more rapidly subdivided so that the nanoparticles are clustered around the defect structure as shown in FIG. 3- (a), and thus the nanoparticles are trapped in the defect structure, To form aggregates.

In addition, the molecules of the defect structure where sublimation is inhibited by the nanoparticles are distorted by the planar anchoring of the surface of the nanoparticles, creating a mixture with the nanoparticles. Thus, when all the liquid crystal molecules are removed by sublimation, aggregates in which the particles are densely assembled can be formed.

As described above, since the defect structure is located between the plurality of guide patterns, the size of the defect structure, the interval between the defect structures, the arrangement of the defect structure, and the like can be adjusted according to the interval and height between the plurality of guide patterns, The nanoparticle assembly is positioned between the plurality of guide patterns, and the size, spacing, arrangement, and the like of the nanoparticle assembly can be adjusted according to the interval and height between the guide patterns.

The temperature of the liquid crystal phase may specifically be a temperature on the Smectic A phase. For example, from 120 to 190 < 0 > C, but is not limited thereto.

The annealing time is not particularly limited and may be appropriately adjusted depending on the thickness of the liquid crystal thin film, the amount of nanoparticles, etc., and may be, for example, 10 seconds to 8 hours, specifically 5 minutes to 8 hours, Preferably from 2 hours to 8 hours, and most preferably from 2 hours to 6 hours, in terms of the uniformity of the solvent.

The aggregate of nanoparticles obtained according to the above step may be spherical in shape, but is not limited thereto.

The size of the nanoparticle aggregate is not particularly limited, and may be, for example, 50 nm to 5 탆.

The method for controlling the size of the nanoparticle aggregate is not particularly limited, and for example, the size of the aggregate can be controlled by controlling the concentration of nanoparticles in the nanoparticle dispersion. When the concentration of nanoparticles in the nanoparticle dispersion is increased, the number of the nanoparticles to be assembled increases, so that the size of the nanoparticle aggregate can be increased. Conversely, if the concentration is lowered, the number of nanoparticles to be assembled can be decreased, .

As described above, the method of the present invention is a method of forming a liquid crystal thin film having a defect structure with sublimable liquid crystal supramolecules and forming a nanoparticle assembly through an annealing process on the thin film, wherein the liquid crystal thin film is removed by sublimation, Only.

In another aspect, the present invention provides a method of adjusting the array of nanoparticle assemblies by adjusting the guide pattern pitch of the nanoparticle assembly.

According to the above-described method of manufacturing a nanoparticle assembly, since the nanoparticle assembly is formed between a plurality of mutually spaced guide patterns, the pitch of the guide patterns can be adjusted to control the arrangement of the nanoparticle assemblies disposed between neighboring guide patterns .

As shown in FIGS. 8 and 9, the pitch of the guide pattern may be reduced or increased to reduce or increase the number of rows of nanoparticle assemblies disposed between neighboring guide patterns.

More specifically, when the height of the guide pattern is 5 占 퐉, the pitch of the guide pattern is 5 占 퐉, and one row of nanoparticle assemblies can be positioned between neighboring guide patterns. When the height of the guide pattern is 5 占 퐉, the pitch of the guide pattern is set to 10 占 퐉 so that 2 to 3 rows of nanoparticle assemblies are positioned between neighboring guide patterns. The nanoparticle assembly may be positioned at about 50 占 퐉 so that about ten rows of nanoparticle assemblies are positioned, but the present invention is not limited thereto.

The adjustment of the pitch of the guide pattern can be performed by adjusting the interval when the guide pattern is formed. For example, in the case of photolithography, it can be performed by adjusting the size of the mask and the interval of the holes. In the case of the scratch, by adjusting the distance between the particles forming the grooves by scratching But is not limited thereto.

The pitch of the guide pattern is preferably 3 to 100 탆, and most preferably 3 to 50 탆. And may be appropriately selected according to the arrangement of the nanoparticle assembly to be implemented within the above range.

In another aspect, the present invention provides a method of adjusting the distance between nanoparticle assemblies by adjusting the height of a guide pattern of the nanoparticle assembly.

According to the above-described method of manufacturing a nanoparticle assembly, a nanoparticle assembly is formed between a plurality of mutually spaced guide patterns. The height of the guide pattern can be adjusted to control the spacing of nanoparticle assemblies disposed between neighboring guide patterns .

In the sublimable liquid crystal supramolecules according to the present invention, the size of the defect structure is controlled according to the thickness of the liquid crystal thin film. Specifically, the thickness of the thin film has a positive correlation with the diameter of the defect structure. Therefore, since the thickness of the nanoparticle assembly is positively correlated with the thickness of the thin film, the distance between the nanoparticle assemblies can be controlled by controlling the thickness of the liquid crystal thin film by adjusting the height of the guide pattern.

As shown in FIGS. 10 and 11, the height of the guide pattern may be reduced or increased to reduce or increase the spacing of the nanoparticle assemblies disposed between neighboring guide patterns.

As the height of the guide pattern increases, the diameter of the nanoparticle assembly increases and the gap of the nanoparticle assembly increases.

The height of the guide pattern can be adjusted by adjusting the height of the guide pattern when forming the guide pattern. For example, it is possible to regulate the thickness of a pattern formed once during photolithography and printing, or to regulate the pattern thickness by forming a pattern a plurality of times, to control the pressure applied at the time of scratching, But is not limited thereto.

The height of the guide pattern is preferably 1 to 20 탆, and most preferably 1 to 10 탆. And may be appropriately selected according to the interval of the nanoparticle assembly to be implemented within the above range.

[ Example ]

Hereinafter, the present invention will be described in more detail by way of examples. It will be apparent to those skilled in the art that these embodiments are merely illustrative of the present invention and that the technical scope of the present invention is not limited to these embodiments.

- LCD Supramolecular  And synthesis of nanoparticles

F-SiO ₂ nanoparticles and multi-shell quantum dots (CdSe / CdS / ZnS) of fluorine (F) series represented by the following formula (2) can be synthesized by a well-known synthesis method (K. Kim et al., Adv. Mater., 2011, 23, 911).

(2)

- Analysis of liquid crystal thin film and nanoparticle assemblies

The liquid crystal thin film and nanoparticle assemblies prepared according to one embodiment of the present invention were observed based on a comprehensive microscopic method. The optical properties of the liquid crystal were observed in order to confirm the micro-sized repeating structure deformed during the heat treatment in real time. For this purpose, a polarizing microscope equipped with a temperature controller (LV 100-POL, Nikon) was used . In order to observe the topographical characteristics of the formation process step by step, four identical samples were prepared, and after 1 hour, 2 hours, and 4 hours after the heat treatment, (FE-SEM, Hitachi, S-4800) at 7 kV at 7 mA electron beam to observe each of the above samples. The observation of the quantum dot nanoparticle assembly was performed using a fluorescence microscope (LV-UDM, Nikon), with a fluorescence filter having an electron excitation wavelength range of 440 to 460 nm and an emission wavelength range of 540 to 560 nm.

Example  1: Liquid crystal thin film formation

In this embodiment, liquid crystal supramolecules are arranged on a silicon substrate, and a liquid crystal thin film is formed by heating and cooling.

First, a guide pattern was formed on a silicon substrate by photolithography as shown in Fig. 1- (a). The pitch and width of the guide pattern were set to 10 탆, 5 탆 and 5 탆, respectively. The pitch and the width were adjusted by adjusting the size of the mask and the spacing of the holes. Respectively.

The silicon substrate on which the guide pattern was formed was exposed to oxygen plasma (100 W, running time 2 min) to provide a substrate environment rich in active electrons. Thereafter, polyethyleneimine (Aldrich, Mw 60,000) was coated on the surface of the substrate by spin coating (4500 rpm, 45 sec), and the surface of the substrate was modified to have a glycol functional group. This allows the liquid crystal supramolecules to have a horizontal orientation (inducing a high interaction with the conjugated electrons of the molecules) on the substrate.

The liquid crystal supramolecules on the powder were placed on the substrate, and the substrate was placed on a hot stage (Linkam LTS 350) and heated to 195 ° C or higher to heat the liquid crystal supramolecules to an isotropic liquid crystal phase (see Fig. 1- (b)).

After the liquid crystal supramolecules reached the isotropic liquid crystal phase, the liquid crystal supramolecules were cooled to a Smectic A phase at a rate of 10 ° C / min for 3 minutes. Thus, a liquid crystal thin film having a TFCD was formed (see Fig. 1- (c)).

Example  2: F- SiO ₂  Manufacture of nanoparticle assemblies

In this example, a F-SiO ₂ (silica chemically surface treated with silica) nanoparticle assembly was prepared.

The liquid crystal thin film having the dimple-shaped topographical defect structure of the TFCD prepared in Example 1 was cooled to room temperature to confirm that the defect structure was maintained.

Figure 1- F-SiO ₂ nano-particle dispersion of 0.01% by weight on the thin film as shown in (d) (dispersion medium Novec7300, 3M) was added dropwise a 50 ㎕ by spin coating (2000rpm, 15s), and until the dispersion medium to dry completely And dried naturally (Fig. 1- (e)). Thus, as shown in FIG. 3 (a), it was confirmed that F-SiO ₂ nanoparticles having a diameter of 100 nm primarily gathered in the recessed portion of the defect structure.

The dried sample was placed on a hot stage (Linkam LTS350) and annealed at a temperature of 160 占 폚 at a Smectic A liquid crystal temperature for 4 hours using a temperature controller (Linkam TMS94) to form a spherical cluster of F-SiO ₂ nanoparticles ) Were formed and observed under an electron microscope (Fig. 1- (f)).

When a solution in which F-SiO ₂ nanoparticles are dispersed is deposited by spin-coating on a TFCD thin film, the deposited nanoparticles are removed during the annealing at the temperature of the Smectic phase (160 ° C.) (B) one hour, (c) two hours, (c) one hour, (c) two hours, and (c) one hour. d) 4 hours).

Example  3: F- SiO ₂  Changes in the size of the assembly depending on the concentration of the nanoparticle dispersion

In this embodiment, it was examined for the size of the F-SiO ₂ nanoparticles assembly in accordance with the concentration of the nanoparticles of the nanoparticle dispersion F-SiO _2.

Except that 0.001 wt.%, 0.005 wt.%, 0.01 wt.%, 0.05 wt.%, 0.1 wt.% And 0.5 wt.% Of the dispersion was dropped into the F-SiO ₂ nanoparticle assembly manufacturing method of Example 2 .

Figure 5 As the F-SiO ₂ increases to exhibit a nano a result of analyzing the size of the electron microscope image and the particles of an assembly according to the concentration of the particle dispersion, in the F-SiO ₂ is 0.001% by weight of the nanoparticle dispersion as a 0.5% by weight of the The size of the aggregate increased from 400 nm to 1.8 ㎛ with a relatively uniform size.

Example  4: Flexible On the substrate  The prepared F- SiO ₂  Manufacture of nanoparticle assemblies

In this example, an F-SiO ₂ nanoparticle assembly was fabricated on a flexible substrate.

Except that a polydimethylsiloxane (PDMS) substrate was used in place of the silicon substrate in the F-SiO ₂ nanoparticle assembly manufacturing method of Example 2.

FIG. 6 shows a PDMS substrate and an electron microscope image on which F-SiO ₂ nanoparticle assemblies are arrayed, and it can be confirmed that PDMS substrates excellent in flexibility can also be performed.

Example  5: Qdot  Manufacture of nanoparticle assemblies

In this example, a quantum dot nanoparticle assembly was prepared by applying a dispersion of quantum dot nanoparticles.

Was prepared in the same manner, except the second embodiment, instead of F-SiO ₂ nanoparticles assembly manufacturing F-SiO _2, nano-particle dispersion of the ways that with quantum dots (CdSe / CdS / ZnS) nanoparticle dispersion of 7 mg / ml .

FIG. 7 shows a glare microscope image of a quantum dot nanoparticle assembly. The quantum dot nanoparticle assemblies having a hexagonal arrangement in a large area of about 1 mm ² were identified, and from images processed by fast Fourier transform (FFT) And it was confirmed that they have a substantially uniform arrangement (see the inset image in Fig. 7).

Example  6: Fabrication of nanoparticle assemblies according to guide pattern pitch

In this example, the arrangement of the nanoparticle assemblies was checked by adjusting the guide pattern pitch.

The height of the guide pattern was fixed to 5 mu m on the silicon substrate by photolithography, and guide patterns were formed with pitches of 5 mu m, 10 mu m, 20 mu m, and 50 mu m, respectively. A nanoparticle assembly was prepared in the same manner as in Example 2 and Example 3 except for the size of the guide pattern.

FIGS. 8 and 9 are cross-sectional schematic views of the guide patterns of the F-SiO ₂ nanoparticle assemblies according to their pitches, polarizing microscope images of the TFCDs formed in the respective guide patterns, and electron microscope images of the nanoparticle assemblies formed using the TFCDs When the height of the guide pattern is 5 占 퐉, it is confirmed that the pitch of the guide pattern is 5 占 퐉, and that one row of nanoparticle assemblies is positioned between neighboring guide patterns. When the height of the guide pattern is 5 占 퐉, two to three rows of nanoparticle assemblies are positioned between neighboring guide patterns at a pitch of 10 占 퐉, and the pitch is set to 20 占 퐉, thereby forming three to four rows of nanoparticles It was found that about 10 rows of nanoparticle assemblies were located at an assembly position and a pitch of 50 μm.

Example  7: Fabrication of nanoparticle assemblies according to guide pattern height

In this example, the distance between the nanoparticle assemblies was checked by adjusting the height of the guide pattern.

The pitch of the guide pattern was fixed to 50 mu m on the silicon substrate by photolithography (Fig. 10- (a) is 20 mu m), and guide patterns having heights of 3 mu m, 5 mu m, 7 mu m and 10 mu m, respectively . A nanoparticle assembly was prepared in the same manner as in Example 2 and Example 3 except for the size of the guide pattern.

FIGS. 10 and 11 are schematic views of the guide pattern height of the F-SiO ₂ nanoparticle assembly, a polarizing microscope image of the TFCD formed in each guide pattern, and an electron microscope image of the nanoparticle assembly formed using the TFCD, It was found that the distance between the nanoparticle assemblies formed in each guide pattern increases from 3 탆 to 10 탆 while the height of the guide pattern increases from 3 탆 to 10 탆.

Claims (11)

Forming a plurality of guide patterns on a substrate;
Disposing sublimable liquid crystal supramolecules between the plurality of guide patterns;
Heating the sublimable liquid crystalline supramolecule and cooling it to a smectic phase to form a liquid crystal thin film; And
Applying a dispersion of nanoparticles on the formed liquid crystal thin film and annealing at a liquid crystal phase temperature,
Wherein the guide pattern has a pitch of 3 to 100 占 퐉 and a height of 1 to 20 占 퐉.
2. The method of claim 1, further comprising forming a guide pattern and then modifying the surface to have a hydrophilic group.
2. The method of claim 1, further comprising forming a guide pattern and then coating the substrate with polyethyleneimine or polyethylene glycol.
The method of claim 1, further comprising forming a guide pattern and then forming a self-assembled monolayer (SAM) with a silica material on the substrate.
The liquid crystal display device according to claim 1, wherein the sublimable liquid crystal supramolecules are rod-shaped liquid crystal molecules having two benzene rings directly substituted with fluorine (F) -based carbon chains and ester groups, ≪ / RTI >
The method of claim 1, wherein the submerged liquid crystalline supramolecules are cooled to form an inverted cone-shaped defect structure.
The method of claim 1, wherein the nanoparticle assembly is sized by controlling the nanoparticle concentration in the nanoparticle dispersion.
The method of claim 1, wherein the nanoparticles are at least one selected from the group consisting of silica nanoparticles, metal nanoparticles, metal oxide nanoparticles, quantum dots, and quantum rods.
The method of claim 1, wherein the nanoparticle assembly is spherical.
10. A method of adjusting the arrangement of nanoparticle assemblies according to the pitch of a guide pattern, the nanoparticle assembly being prepared by the method of any one of claims 1 to 9 and having a guide pattern pitch of 3 to 100 m.
10. A method of adjusting the distance between nanoparticle assemblies according to the height of a guide pattern produced by the method of any one of claims 1 to 9, wherein the guide pattern height of the nanoparticle assembly is 1 to 20 m.

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