KR100764826B1 - Pixellated photonic crystal films for the applications of reflective mode display and photonic waveguide and fabrication method thereof - Google Patents

Abstract

A pixellated photonic crystal film for a reflective display device and photonic waveguide and a method for manufacturing the same are provided to simplify process steps by simultaneously controlling a reflected color through a micro patterning process and band gap tuning. A photonic crystal film of inverse opal structure is formed by forming a colloidal crystal film on a substrate, filling spaces of colloidal crystals with a crosslink monomer, and etching nano-particles. A transparent film is formed by re-implanting the inverse opal film with optical crosslink monomer. A mask pattern is put on the transparent film, and then the transparent is irradiated by ultraviolet rays and is developed.

Description

Pixelated Photonic Crystal Films for the Applications of Reflective Mode Display and Photonic Waveguide and Fabrication Method Thereof}

1 is a schematic diagram showing a method for producing an inverted opal and its patterned structure.

Figure 2 is a photo showing the opal film prepared by using a dip coating of the nanoparticle suspension and the reverse opal structure formed by injecting a photocrosslinkable polymer and etching the nanoparticles.

3 is an optical and electron micrograph showing the patterned structure of the prepared inverse opal film.

4 is an optical microscope photograph of an inverse opal film having two colors using an incomplete development method of a photocrosslinkable monomer.

FIG. 5 is a scanning electron micrograph showing the internal structure change of the inverse opal film that changes as the time for using the incomplete development of the photocrosslinkable monomer is adjusted. FIG.

6 is a computer simulation showing the change of the optical band gap according to the volume reduction of the micropores inside the reverse opal film.

7 is a computer simulation result showing that the color of the reflected light changes according to the change of the optical band gap.

8 is a schematic diagram of a manufacturing process of an inverse opal film having a mosaic pattern of three colors for application to a reflective display device;

FIG. 9 is an optical microscope photograph of an inverse opal film of three colors actually manufactured according to the manufacturing process of FIG. 8 (pixel size of 50 μm)

10 is a reflection spectrum result showing the reflection characteristics of the prepared three-color reverse opal film pattern.

11 is a comparison of the components of the conventional display devices and the reflective screen display device proposed through the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pixelated photonic crystal film and a method of manufacturing the same for application of a reflective display device and an optical waveguide.

Colloidal crystals having a microstructure have attracted much attention because they can be used in various fields, such as display devices, optical communication, catalyst carriers, biosensors, and acoustic materials.

In the case of colloidal crystals using self-assembly, it is difficult to manufacture in a large area and many defects are the biggest limitations in practical use, but in recent years, spin coating for arranging nanoparticles using a rotating substrate in the world Practical solutions have been proposed to solve the above problems based on a variety of methods including spin-coating and dip-coating, in which nanoparticles are regularly arranged at the interface of air with a suspension of nanoparticles dispersed therein.

 Therefore, the remaining task in the practical application of colloidal crystals can be said to be a technique for patterning and tuning the colloidal crystals to the desired shape so that they can be applied to the intended use. Some researchers have proposed two-photon polymerization or self-assembly on patterned substrates. However, two-photon polymerization has many problems in terms of economics and productivity, and self-assembly on patterned substrates. It takes a long time, and it is difficult to produce a complex pattern such as pixels. In addition, there is a problem that can not be applied to a structure having a superior optical characteristics, such as inverse opal (structure).

The present invention solves the above-mentioned complex problems in the patterning of photonic crystals, and at the same time develops a technique for tuning the characteristics of photonic crystals in a desired direction, the self-assembly photonic crystal formation characteristics and photoetching techniques ( We propose a complex process that combines tuning and patterning characteristics of photolithography.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pixelated photonic crystal film and a method of manufacturing the same for application of a reflective display device and an optical waveguide. More specifically, a pixelated (or patterned) photonic crystal film for a reflective display device selectively reflecting light of a specific wavelength, a method of manufacturing the patterned film using a self-assembly method and an optical etching method, and the film It relates to a reflective screen display device comprising a.

In general, a liquid crystal display device applies a voltage to a liquid crystal positioned between two electrodes, so that the physical orientation of the liquid crystal is changed according to the voltage, and the optical shutter function blocks or passes the light from the light source at an individual pixel level. The image is integrated.

The liquid crystal display device includes a transmissive liquid crystal display device in which a rear light source assembly is disposed on a rear surface of the liquid crystal panel so that light from the backlight passes through the light guide plate and is applied to the liquid crystal panel. There is a reflection type liquid crystal display device in which a reflector disposed in the back diffuses the light back to the liquid crystal panel.

11A is a schematic diagram showing a display mechanism of a transmissive liquid crystal display, and FIGS. 11B and 11C are schematic diagrams showing a display mechanism of a reflective liquid crystal display. 11A, 11B, and 11C, A denotes an analyzer plate, P denotes a polarizing plate, LCD denotes a liquid crystal display panel, and R denotes a rear reflector.

Among these, the reflective liquid crystal display device has various advantages over the transmissive liquid crystal display device. This is because the separate device for providing light is not arranged or additionally arranged, and it is configured to reflect external light, so that it can be used without a backlight outdoors, which greatly reduces power consumption. Compared to the strong sunlight, it can be seen more clearly, and the device has the advantage of being lightweight and miniaturized in recent years, the application of note PC (Personal cumputer), PDA (Personal Didital Assistant) or personal portable electronic devices, etc. is increasing.

It is an object of the present invention to provide a method for producing an inverse opal crystal pattern.

Another object of the present invention is to provide a method of manufacturing an optical waveguide using an inverse opal pattern.

Another object of the present invention is to provide a method for manufacturing a photonic crystal film including a pixel pattern that emits red, green, and blue reflected light using multiple photolithography.

Still another object of the present invention is to provide a method of manufacturing a reflective screen display device using the photonic crystal film as a color filter and a rear reflector.

The present invention comprises the steps of: a) forming a colloidal crystal film on the substrate and filling the crosslinkable monomer between the formed colloidal crystals and etching the nanoparticles to produce an opal photonic crystal film; And

b) reinjecting a photocrosslinkable monomer into the reverse opal film to produce an optically clear film; And

c) a method of manufacturing a photonic crystal film comprising placing a mask pattern for photoetching on the transparent film and irradiating UV light to selectively photopolymerize and develop.

In the step c), a photocrosslinkable polymerization reaction may be completely or partially through a photoetching mask having a pattern drawn to irradiate UV light, and various structures may be formed in the development process according to the degree of polymerization.

The reflected light that is selectively reflected when the light is incident on the photonic crystal film obtained by photopolymerization by irradiating UV light may emit various reflected light according to the diameter of the nanoparticles and the refractive index of the monomer.

The photonic crystal film is manufactured using nanoparticles each having a dispersion degree of particle diameter of less than 5% and arranged in a regular pattern, and having an average particle diameter of 180 nm to 1000 nm.

In the above initial photonic crystal film may be used nanoparticles each containing any one selected from the group consisting of polystyrene, polymethyl methacrylate, silica.

The photonic crystal pattern may be formed according to a linear, lattice, or circular pattern having a width of 20 to 200 μm in the form of a photoetch mask.

As the crosslinkable monomer for preparing the reverse opal film, any one selected from epoxy-based and ETPTA or acrylate-based crosslinkable monomers may be used.

The present invention includes a photonic crystal film produced by the above-mentioned method.

The photonic crystal film produced by the above-mentioned method can give a monochromatic or multicolored reflected light in the form of the photonic crystal pattern.

The photonic crystal film produced by the above-mentioned method may have two portions, an optically transparent portion and a portion reflecting selected light.

The photonic crystal film produced by the above-mentioned method can be used as an optical waveguide for guiding light using the patterned photonic crystal film using the transparent portion of the pattern and the reflected portion. .

The present invention comprises the steps of a ') injecting a photocrosslinkable monomer into the reverse opal film following the above-mentioned a) to b) process;

b ') placing a mask pattern for photoetching on the transparent film and irradiating an insufficient amount of UV light to completely polymerize the photocrosslinkable monomer to form a portion having two different exposure degrees on the film; And

c ') a photoetching mask pattern is placed on the film at different angles and irradiated with an insufficient amount of UV light to fully polymerize the photocrosslinkable monomer to form a portion having 3 to 4 different exposure degrees on the film. step; And

d ') shows a method for producing a pixelated photonic crystal film comprising developing and washing it with a developer to selectively produce a film that reflects light of a different wavelength.

The present invention includes a pixelated film produced by the method comprising the steps a ') to d').

The pixelated film can optically reflect light of three to four different wavelengths.

The present invention includes a reflective screen display device manufactured by using the property that the pixelated photonic crystal film produced by the method comprising the steps a ') to d') may selectively emit reflected light having a different wavelength. do.

The present invention is a film prepared by the method comprising the steps a) to c) or the film prepared by the method comprising the steps a ') to d') of the above is reflected through the following formula The color to be determined can be determined.

λ = 2dn _{eff ...} [Equation 1]

In Formula 1, λ is the wavelength of the reflected light, d is the average interlayer distance to the <111> crystal direction of the nanoparticle crystal defined by the formula 2, n _eff is the effective refractive index of the inverse opal film defined according to the formula ;

...[계산식 2]

... [Calculation 2]

In Formula 2, D is the average particle diameter of the initial nanoparticles,

...[계산식 3]

... [Calculation 3]

In Formula 3, f _m is the volume fraction of the medium surrounding the particles, n _m is the refractive index of the medium, n _p is the refractive index of the air.

Hereinafter, the present invention will be described in more detail.

[Production of Reverse Opal Pattern]

Self-assembly-photolithography fusion pattern technology is a photonic crystal structure having a regular structure at the nano-level is prepared by the self-assembly of nanoparticles, the shape control of the colloidal crystal having a desired shape at the micrometer level, or the band gap of the photonic crystal In the characteristic tuning, it can be said to be a bottom-up top-down fusion process using an optical etching process. In general, in order to form a regular structure at the nano level, high energy wavelengths such as DUV or e-beam need to be used, which requires very expensive equipment and the manufactured pattern is also limited to a two-dimensional substrate. There is a problem in controlling it. Etching methods such as holographic lithography and two-photon polymerization have been proposed to form regular nanostructures in three dimensions, but they also require expensive equipment and are applied to light with wavelengths in the visible range. Not only does it require complex processes, but it also has to be more economical to manufacture large-area nanostructures. On the other hand, the process using self-assembly of colloidal particles can produce colloidal crystals in various wavelength ranges by producing particles having various sizes, and it does not require expensive manufacturing equipment and complicated processes. Has the advantage in In addition, when the particles synthesized from various materials are used, the band gap characteristics of the photonic crystal may be controlled accordingly, and specific optical properties such as nonlinear optical characteristics or light emission may be expected.

Photolithography is a general etching process used in the existing semiconductor process and is the most reliable process that can produce the micrometer unit pattern having the desired shape most economically. This method has the advantage of controlling the shape of the colloidal crystal structure with nano level regularity at the micrometer level by applying the photolithography process to control the shape of the photonic crystal structure. 1 shows a schematic diagram of fabricating a patterned colloidal photonic crystal.

First, colloidal crystals are prepared on a substrate using a dip-coating method or a capillary crystallization method as shown in FIG. 1 (i). Fill the photoresist material containing the photocrosslinkable epoxy in the space of the prepared colloidal crystal and crosslink it using the photopolymerization process, and then dissolve the colloidal crystal using hydrofluoric acid as shown in (ii). The film is made. When the resulting film is filled with the photosensitive photoresist again as shown in (iii) and irradiated with a photo-mask engraved with a pattern as shown in (iv) and ultraviolet light in parallel, only the desired part is selectively lighted along the shape of the photomask. This is investigated. When heated to 90 ℃ using soft-baking process, crosslinking reaction occurs only at the part irradiated with light selectively. As shown in (v), when the part which is covered by the photomask and covered by the photopolymerization is not melted again, the pore structure of the opal structure inverted is regenerated while the photopolymerized part is completely filled and optically dissolved. It remains transparent.

2 shows optical and electron micrographs of colloidal photonic crystals and their inverted films prepared using dip coating. That is, FIG. 2 is a photo showing an opal film prepared by deep coating of a nanoparticle suspension and an inverse opal structure formed by injecting a photocrosslinkable polymer into the nanoparticles and etching the nanoparticles, and FIG. 2 (a) selectively reflects green light. The opal structure is a dip coating picture and an electron microscope picture, Figure 2 (b) is a photo and electron micrograph of the inverted opal film that selectively reflects blue green light.

When the structure is inverted from the photonic crystal of the surface-centered cubic structure made of silica particles, which is an inorganic material, a blue shift phenomenon occurs in which the wavelength of reflected light approaches blue. This is consistent with theoretical predictions through Maxwell's calculation.

3 shows the patterned structure of the inverted opal structure photonic crystal produced through the above process. Fig. 3 (a) is a 50 times optical micrograph (scale bar shows 50 um), and Fig. 3 (b) is a scanning electron microscope photograph magnified 20000 times at the pattern boundary.

As shown in the photo, the pattern of the photonic crystal is transferred by the photolithography process along the shape of the mask, which means that the regular structure at the nano level and the micro level pattern can be freely patterned in a hierarchical form. Since this process is based on the photolithography process, it has the advantage that the existing semiconductor process infrastructure can be used as it is in patterning colloidal photonic crystals. It is also a proven process in economics and productivity, and thus has advantages in practical use. Patterned photonic crystals have a wide range of applications for colloidal crystals, ranging from photonic waveguides and optical filters to optical switches and ultimately to photonic integrated circuits. It can be extended.

[Color Control of Reverse Opal Structure]

What is required in patterning the inverted photonic crystal structure is the question of whether the optical bandgap, i.e. the wavelength of the reflected light, can be tuned at the same time in forming the desired pattern. In recent years, several researchers have been investigating varying band gaps by filling colloidal photonic crystals with other materials to change the effective refractive index of the entire material. For example, when filling liquid crystal molecules into colloidal photonic crystals or inverted opal photonic crystals, the bandgap can be tuned according to the direction and intensity of the electric field. However, liquid crystal molecules have limitations in application to patterned photonic crystals because it is impossible to tune the band gaps of selective portions. On the other hand, in the photopolymerization of the photoresist material, the reaction rate and the reaction stage are determined by the concentration of the cation generated, which is related to the total energy of the irradiated UV light. At this time, as the exposure time of the UV light decreases, the concentration of the cation for initiating the reaction decreases, thereby slowing down the rate of the polymerization reaction. Therefore, it is possible to control the degree of polymerization by adjusting the exposure time of UV light under specific conditions, which directly affects the development process of photoresist. Therefore, the development of photoresist is incomplete during the development of the second photoresist injected. Change the microstructure. As shown in FIG. 4, the bandgap of the patterned photonic crystal may be tuned by irradiating UV light for a short time to induce incomplete polymerization conditions.

Unlike the existing process, this process can be simplified because the tuning process and patterning process are performed at once, and it has the effect of improving the economic efficiency by shortening the process time.

FIG. 5 is a conceptual diagram and a scanning electron micrograph showing a change in microstructure of the inverted photonic crystal according to the irradiation time of UV light.

Using a computer simulation tool, it is possible to predict and control the change of the optical bandgap with the change of UV irradiation time. Using the plane wave expansion method or the finite element time domain method, it is possible to calculate the energy band gap of a photonic crystal by specifying boundary conditions from the undifferentiated equation of Maxwell's equation. .

In calculating the energy band gap of a photonic crystal, it is necessary to select appropriate process variables. The refractive index of the photonic crystal constituent particles, as well as the refractive index of the filling material, is also a process variable when forming an inverted opal structure. In particular, in the case of applying the incomplete development technique, the pore size changes according to the exposure time of the UV light, which causes a change in the effective refractive index of the material. Equation 1 can be used to predict the degree of change in the effective refractive index of a material depending on the degree of filling of pores.

...식 (1)

... (1)

n _eff represents the effective refractive index n _s of the material, n _air represents the refractive index of the colloidal particles and the filling material. f _s represents the volume fraction of the particles and is about 74% in the case of face-centered cubic structures.

6 shows a process of changing the microstructure with increasing exposure time. 6 shows the change of the optical band gap according to the change of pore volume. In the case of the photoresist used in the present invention, the optimum exposure conditions were shown in 10 seconds. In this case, the perfect crosslinking reaction occurs as the appropriate exposure is applied, and thus the pores are completely infiltrated by the secondly injected photoresist. In this case, since the background material and the filled material are the same, the refractive index is the same, and thus the optically transparent property is obtained.

On the other hand, since no crosslinking reaction occurs when no UV light is irradiated, the secondary injection photoresist is completely melted by the developer. In the case of irradiating UV light with incomplete exposure conditions of 3 seconds and 6 seconds, the crosslinking reaction is partially progressed, partially developed and only partially melted, so that the size of pores in the microstructure can be seen to decrease. Since the lattice constant is constant, the change in effective refractive index caused by the volume fraction becomes the real process variable, and we can predict the change of the optical band gap by computer simulation. FIG. 7 shows the change of the optical band gap calculated by the finite element time domain method, and shows the change of the band gap according to the pore size and the shift of the reflected wavelength due to the band gap.

Figure 7a shows the change in pore size with the change in volume fraction, Figures 7b and 7c shows the change in bandgap at 100% pore size and 80% pore size. The Y-axis represents normalized energy, which can predict the wavelength of light reflected by the bandgap. Figure 8 shows the change of the bandgap position and the reflected wavelength according to the pore size.

Fabrication of Inverse Opal Pixels Using Multiple Photolithography

We have developed multiple photolithography techniques to apply incomplete development techniques to more complex processes. Multiple exposure technology is a technique that exposes two or more times by changing the photomask pattern in one sample, there is an advantage that can be controlled more various exposure in photoresist. For example, when a pattern is manufactured using a photomask pattern having a regular line-shaped pattern, two regions in which UV light does not reach are generated by being masked by a portion irradiated with UV light and a photomask pattern. At this time, if the UV light is irradiated again by rotating the line-shaped photomask pattern by 90 degrees, three parts of the region irradiated with UV light twice, the once irradiated area, and the unirradiated area appear on the sample. When applied to the incomplete development of the photonic crystal pattern of the inverted opal structure and applied to it, it is possible to produce a pixel-shaped photonic crystal pattern having a difference in the irradiation time in three areas as shown in FIG.

FIG. 9 illustrates a pixel-shaped photonic crystal pattern manufactured through an actual process through a process step for manufacturing the pixel-shaped photonic crystal pattern of FIG. 8. RGB A pixelated photonic crystal that reflects three colors (the scale bar represents 100 μm).

In order to apply the pixelated photonic crystal structure to the actual display device, it is necessary to analyze the optical characteristics of the fabricated photonic crystal pattern. Therefore, the researchers performed the reflection spectroscopic analysis to measure the reflective characteristics of the photonic crystal. Light generated from a 150W xenon light source was collected through a 10-fold objective lens and irradiated onto the sample, and the light reflected from the sample was analyzed by a spectrophotometer.

10 is a result of spectroscopic analysis of light reflected by a pixelated photonic crystal pattern through spectroscopic analysis. In FIG. 10, spectroscopic analysis results of pixilated photonic crystal patterns reflecting RGB three colors. Reflective peaks were detected at about 510 nm, 545 nm, and 580 nm, which is consistent with the results observed by optical microscopy.

<Example 1>; Manufacture of reverse opal film

The manufacturing process of the reverse opal film is shown in FIG. Oxygen plasma is treated on the glass substrate to make the surface hydrophilic, and then the substrate is immersed in about 5% of 250 nm silica colloidal solution to the extent that the glass substrate is coated and pulled up at a speed of 2 mm per hour using a stage controller. After about 5 hours, the prepared colloidal crystals can be obtained. The thickness of the photonic crystal coated on the glass substrate can be adjusted according to the pulling speed and the concentration of the solution. After that, a silicon wafer is prepared and attached to the crystal surface of the glass substrate prepared through the above process, and then the epoxy-based photocrosslinkable monomer is injected into the gap and dried. As the crosslinkable monomer, an epoxy series including SU-8 (manufactured by Microchem, USA) and an acrylate crosslinking monomer including ETPTA (Ethoxylated Trymethylolpropane Triacrylate) may be used.

At this time, the monomer is crosslinked using UV or heat to make it resistant to acid or organic solvent. When the substrate is immersed in 5% hydrofluoric acid (HF), the silica particles and the glass substrate are melted, and the photoresist is not affected. Thus, an inverse opal film is formed on the silicon substrate. At this time, hydrofluoric acid is very dangerous and should be cleaned and dried.

The crosslinkable monomer for preparing an inverse opal film uses an epoxy-based group including SU-8 and an acrylate-based crosslinkable monomer including ETPTA.

(Formation of reverse opal pattern)

Injecting the photo-crosslinkable monomer into the reverse opal film, and drying for 12 hours at a temperature of 95 ℃ using a vacuum oven to form an optically transparent film, which is the refractive index of the reverse opal film and the injected photo-crosslinkable monomer This is because the engineering is the same.

Place a photo-etching mask with a pattern on the transparent film to selectively irradiate light, and direct UV light having a wavelength of 365 nm for 10 seconds, which is enough time to transfer energy for the photopolymerization. When heated on a hot plate for 4 minutes, the photocrosslinkable polymerization reaction proceeds only at the portion irradiated with UV light.

After immersing it in developer (PGMEA; propylene glycol monomethyl triacrylate) and washing it with ultrasonic waves for about 1 hour, the uncrosslinked monomer is completely developed and melted into the developer, and the crosslinked portion does not melt. After rinsing the film with isopropyl alcohol (IPA) and drying, the photonic crystal pattern as shown in FIG. 3 is generated.

<Example 2>

Injecting the photo-crosslinkable monomer into the reverse opal film prepared by the method of Example 1, and dried for 12 hours at a temperature of 95 ℃ using a vacuum oven to form an optically transparent film, on the transparent film A photo-etching mask with a pattern drawn to selectively irradiate light, and UV light having a wavelength of 365 nm is directly exposed for 3 to 6 seconds, which is insufficient time for the photocrosslinking polymerization reaction to proceed, and a hot plate having a temperature of 95 ° C. When the phase is heated for 4 minutes, the photocrosslinkable polymerization reaction proceeds only in the portion irradiated with UV light. Unlike Example 1, the photocrosslinkable polymerization reaction does not proceed completely but only partially. Therefore, an incomplete development process occurs even in a portion hit by UV light in the development process using a developer, which changes the microstructure of the inverse opal and consequently changes to a part having different physical optical properties. 4 is an optical micrograph showing a photonic crystal having two colors produced by the above method, Figure 5 shows a schematic diagram and an electron micrograph showing the appearance of the internal structure changes with increasing irradiation time of UV light.

<Example 3>

The incomplete development technique presented in Example 2 may also be applied to the production of multicolored pixelated photonic crystal films that can be applied to reflective display devices. Injecting the photo-crosslinkable monomer into the reverse opal film prepared by the method of Example 1, and dried for 12 hours at a temperature of 95 ℃ using a vacuum oven to form an optically transparent film, on the transparent film If you put on the photo-etching mask with the line pattern of 50㎛ interval to irradiate the light selectively and irradiate UV light with the wavelength of 365nm for 3 seconds, the part irradiated with the light for 3 seconds on the film is different Two parts will be created. At this time, if the photo-etching mask with a line pattern of 50 μm intervals is rotated by 90 degrees, the UV light is applied again by intersecting with the part where UV light is applied before, and the UV light is hit twice on the film for a total of 6 seconds. Three areas are created: the part irradiated with energy, the part irradiated with light energy for 3 seconds once, and the part not irradiated with light.

 When heated on a hot plate at 95 ° C for 4 minutes, the photocrosslinkable polymerization reaction proceeds only in the part irradiated with UV light, but the photocrosslinkable polymerization reaction does not proceed completely but only partially, and partially proceeds. The crosslinking polymerization also proceeds to a different degree in a portion where light is applied for 6 seconds and a portion where light is applied for 3 seconds. Therefore, in the developing process using a developing solution, an incomplete developing process occurs with different degrees depending on the irradiation time of UV light, which forms three different microstructures on the film of the opal, resulting in pixelation of the three It is possible to manufacture a photonic crystal film having a property of reflecting other light.

8 is a schematic diagram showing a pixelated photonic crystal film through the above process, FIG. 9 is an optical micrograph of the prepared photonic crystal, and FIG. 10 is a result of reflection spectroscopy showing its reflection characteristics.

The photonic crystal patterning technique proposed through the present invention can be applied to a wide range from a simple pattern technique that can be applied to an optical waveguide, to a pixelated photonic crystal film that can be applied to a reflective display device. In particular, in the present process, since the control of the reflection color through the fine patterning process and the tuning of the band gap is performed at the same time, there is an advantage that the process step can be simplified. In addition, since the self-assembly of colloidal particles is used in the control of nanostructures and the photolithography method, which is well known in the control of patterns, economical and compatibility are simultaneously achieved. In addition, the colloidal particles and the filling material can be selected, which makes it possible to select a reasonable material according to the characteristics in actual device formation.

The optical reflecting plate of the present invention may exhibit reflected light of various colors, and has an advantage of making the color of the reflective screen display device more clear. In addition, the manufacturing method of the optical reflector of the present invention simplified the process by the method of patterning on the substrate using a nano-particle crystal and multiple optical etching method, the reflective screen display device comprising the optical reflector of the present invention is a backlight Since it does not require a backlight, it can save energy and provide clear picture quality even under sunlight.

Claims (15)

a) forming a colloidal crystal film on a substrate, filling a crosslinkable monomer between the formed colloidal crystals, and etching nanoparticles to prepare an opal photonic crystal film; And b) reinjecting a photocrosslinkable monomer into the reverse opal film to produce an optically clear film; And c) placing a mask pattern for photoetching on the transparent film and irradiating UV light to selectively photopolymerize and develop the photonic crystal film. According to claim 1, wherein the step c) is a photo-crosslinkable polymerization reaction is completely or partially through the photo-etching mask is patterned to irradiate UV light to form a variety of structures in the development process according to the degree of polymerization Characterized in that the method for producing a patterned photonic crystal film.  The patterned photonic crystal film of claim 1, wherein the reflected light selectively reflected when the light is incident on the photonic crystal film obtained by photopolymerization by irradiating UV light produces various reflected light according to the diameter of the nanoparticles and the refractive index of the monomer. Manufacturing method. The patterned photonic crystal of claim 1, wherein each of the photonic crystal films is manufactured using nanoparticles each having a dispersion degree of particle diameter of less than 5% and arranged in a regular pattern, and having an average particle diameter of 180 nm to 1000 nm. Method for producing a film. The method of claim 1, wherein the initial photonic crystal film comprises nanoparticles each including any one selected from the group consisting of polystyrene, polymethyl methacrylate, and silica. The method of claim 1, wherein the photonic crystal pattern is formed according to a linear, lattice, or circular pattern having a width of 20 to 200 μm. The method of claim 1, wherein the crosslinkable monomer for preparing the reverse opal film is selected from an epoxy series and an ETPTA or acrylate based crosslinkable monomer. The photonic crystal film manufactured by the method of any one of Claims 1-7. A patterned photonic crystal film, characterized in that the form of the photonic crystal pattern produced by the method of any one of claims 1 to 7 produces a single color or multicolored reflected light. The film produced by the method of claim 1 has two portions, an optically transparent portion and a portion reflecting selected light. A method of using a patterned photonic crystal film prepared by the method of claim 1 as a light guide to guide light using a transparent portion of a pattern and to guide light using a reflected portion. a ') injecting a photocrosslinkable monomer into the inverse opal film following the process a) to b) of claim 1; b ') placing a mask pattern for photoetching on the transparent film and irradiating an insufficient amount of UV light to completely polymerize the photocrosslinkable monomer to form a portion having two different exposure degrees on the film; And c ') a photoetching mask pattern is placed on the film at different angles and irradiated with an insufficient amount of UV light to fully polymerize the photocrosslinkable monomer to form a portion having 3 to 4 different exposure degrees on the film. step; And d ') manufacturing the film by using the developer and washing it to produce a film that selectively reflects light of a different wavelength. 13. The pixelated photonic crystal film of claim 12, wherein the film produced by the method of claim 12 selectively reflects light of three to four different wavelengths optically. A reflecting screen display device manufactured by using a property in which a pixelated photonic crystal film produced by the method of claim 12 can selectively emit reflected light having a different wavelength. 13. The photonic crystal film of claim 1 or 12, wherein the color to be reflected is determined by the following formula: λ = 2dn _{eff ...} [Equation 1] In Formula 1, λ is the wavelength of the reflected light, d is the average interlayer distance to the <111> crystal direction of the nanoparticle crystal defined by the formula 2, n _eff is the effective refractive index of the inverse opal film defined according to the formula ;

... [Calculation 2] In Formula 2, D is the average particle diameter of the initial nanoparticles,

... [Calculation 3] In Formula 3, f _m is the volume fraction of the medium surrounding the particles, n _m is the refractive index of the medium, n _p is the refractive index of the air.

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