KR20240052338A - Infrared Blocking Optical Filter Using Plasmon Nano-Particles Applicable in Hypersonic Flow - Google Patents

Abstract

The present invention relates to an infrared blocking optical filter using plasmonic nanoparticles applicable to hypersonic flow, and more specifically, to a matrix; and an infrared absorption layer formed on the substrate and manufactured using a nanocrystal material capable of semiconductor doping, and an infrared blocking optical filter using plasmonic nanoparticles applicable to hypersonic flow.

Description

Infrared Blocking Optical Filter Using Plasmon Nano-Particles Applicable in Hypersonic Flow}

The present invention relates to an infrared blocking optical filter using plasmonic nanoparticles, and more specifically, to a technology for an infrared blocking optical filter using plasmonic nanoparticles applicable to hypersonic flow that can block infrared rays using plasmonic nanoparticles.

Plasmon refers to a pseudo-particle in which free electrons in a metal vibrate collectively. In metal nanoparticles, plasmons exist locally on the surface, so they are also called surface plasmons. Among them, in metal nanoparticles, light absorption occurs when plasmons couple with the electric field of light in the visible or near-infrared range, resulting in vivid colors. This phenomenon is called surface plasmon resonance, and generates a locally greatly increased electric field. This means that light energy is converted to surface plasmon and accumulated on the surface of the metal nanoparticle, and it also means that light control is possible in an area smaller than the diffraction limit of light. The interaction between these metal nanoparticles and light has recently been attracting attention in the field of optical technology.

Metals are often regarded as three-dimensional crystals of positively charged ions, and the free electrons from each metal atom move the periodic conduction band on the surface of the ionized metal. Plasmons generated by the vibration of these electrons play an important role in the optical properties of metals. For example, light with a frequency lower than the plasma frequency is reflected because the electric field is blocked by electrons on the metal surface, and light with a frequency higher than the plasma frequency is transmitted.

The energy of plasmon can be calculated using the free electron model as follows.

Surface plasmons refer to polaritons created when plasmons bound to a metal surface interact strongly with incident light. It mainly occurs in a vacuum or at the interface with a material with a positive dielectric constant (i.e., dielectric) and has a negative dielectric constant. The resonance of this surface plasmon is mainly used in biochemistry to study the binding mechanisms of ligands and receptors, such as the binding of enzymes and substrates.

Meanwhile, conventional supersonic material technology not only does not block infrared sunlight, but there is no optical material that can withstand the extreme environment of shock waves from supersonic flight approaching Mach 5. Therefore, as shown in FIG. 7, when the aircraft 10 to be tracked is located behind the sun, there was a problem in securing visibility due to saturation of the infrared signal.

Republic of Korea Patent No. 10-1903884

The technical problem to be solved by the present invention is to provide an infrared-blocking optical filter using semiconductor-type plasmonic nanoparticles as a material capable of transmitting far-infrared rays and realizing strong infrared absorption.

In addition, the technical problem to be achieved by the present invention is to provide an infrared-blocking optical filter by fixing plasmonic nanoparticles applicable to hypersonic flow to a substrate.

In addition, the technical problem to be achieved by the present invention is to block infrared spectrum radiation from solar black-body radiation energy by attaching plasmonic nanoparticles to a substrate to compensate for the blind spot angle of infrared heat detection. It provides an optical filter.

However, the technical problem to be achieved by the present invention is not limited to the technical problem mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. You will be able to.

In order to achieve the above technical problem, in one embodiment of the present invention, a matrix (matrix); and an infrared absorption layer formed on the substrate and manufactured using a nanocrystal material capable of semiconductor doping. It provides an infrared blocking optical filter using plasmonic nanoparticles applicable to hypersonic flow.

In one embodiment of the present invention, the infrared absorption layer includes indium tin oxide (Sn:In2O3), tungsten oxide (WOx), molybdenum oxide (MoOx), zinc oxide (ZnO), titanium oxide (TiO2), and aluminum oxide (Al2O3). ), vanadium oxide (V2O3/VO2), hafnium oxide (HfO2), cerium oxide (CeO2), copper sulfide (CuSx), silicon nitride (SiN), and titanium nitride (TiN). It can be included.

In one embodiment of the present invention, the doping element for the semiconductor type doping may be injected into the nanocrystal material in an amount of 15% or less.

In one embodiment of the present invention, the doping element is tin (Sn), zirconium (Zr), cerium (Ce), cesium (Cs), aluminum (Al), gallium (Ga), indium (In), tungsten ( W), and may contain one or more cations selected from the group consisting of molybdenum (Mo).

In one embodiment of the present invention, the doping element may include one or more anions selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and element vacancy.

In one embodiment of the present invention, the infrared absorption layer may absorb infrared rays in the 5,000-3,000/cm partn band.

In one embodiment of the present invention, the shape of the plasmonic nanoparticle may be any one of a sphere, a cube, a polyhedron, or a non-uniform shape.

In one embodiment of the present invention, the infrared absorption layer may be formed as a single layer of nanoparticles through spin coating or liquid-air interface deposition.

In one embodiment of the present invention, the infrared absorption layer may be formed into a multilayer structure of nanoparticles through spray coating or blade coating.

In one embodiment of the present invention, the substrate may be automobile glass.

According to one embodiment of the present invention, when semiconductor-type plasmon nanoparticles applicable to hypersonic flow are confined to a substrate, the free electron plasmon resonance band is located in the near-infrared spectrum region, thereby blocking solar heat and securing high transmittance in the far-infrared region. There is a possible effect.

In addition, according to the present invention, by attaching a solar heat blocking film to the surface of the sensor of a supersonic aircraft, radiation in the infrared spectrum region from solar black-body radiation energy is blocked from the infrared sensor, thereby supplementing the blind spot angle of infrared heat detection. There is.

However, the effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

Figure 1 is a schematic diagram of an infrared blocking optical filter using plasmonic nanoparticles according to an embodiment of the present invention.
Figure 2 is a graph of an experiment to verify whether the infrared blocking function is maintained after applying a supersonic shock wave of plasmonic nanoparticles according to an embodiment of the present invention.
Figure 3 is a photograph of a spherical infrared-absorbing plasmonic particle according to an embodiment of the present invention.
Figure 4 is a photograph of cube-shaped infrared-absorbing plasmonic particles according to an embodiment of the present invention.
Figure 5 is a photograph of a non-uniform infrared-absorbing plasmonic particle according to an embodiment of the present invention.
Figure 6 is a flow chart for manufacturing an infrared absorption layer using plasmonic nanoparticles according to an embodiment of the present invention.
Figure 7 is a schematic diagram illustrating supplementing the blind spot angle caused by sunlight with an optical filter attached to an infrared detector of a supersonic aircraft according to an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the attached drawings. However, the present invention may be implemented in various different forms and, therefore, is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts unrelated to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, combined)" with another part, this means not only "directly connected" but also "indirectly connected" with another member in between. "Includes cases where it is. Additionally, when a part is said to “include” a certain component, this does not mean that other components are excluded, but that other components can be added, unless specifically stated to the contrary.

The terms used in this specification are merely used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

Figure 1 is a schematic diagram of an infrared blocking optical filter 110 using plasmonic nanoparticles according to an embodiment of the present invention.

As shown in Figure 1, in one embodiment of the present invention, a matrix 101 and an infrared absorption layer formed on the matrix 101 and manufactured using a nanocrystal material capable of semiconductor type doping. An infrared blocking optical filter (110) using plasmonic nanoparticles containing (102) is provided. In one embodiment of the present invention, a doping element is added to produce semiconductor-type plasmonic nanoparticles. The free electrons (free carriers) in the nanoparticles are induced by semiconductor-type doping to generate infrared light absorption. The nanocrystals can be manufactured by sputtering or thermal vaporization under an inert gas atmosphere, or by using a sol-gel process. Unlike general crystalline metals, nanocrystal materials have very small grain sizes, so the proportion of atoms randomly distributed near grain boundaries is very high, so the area of the grain boundaries occupies a large portion. Due to the very small crystal grain size, a large proportion of atoms are located at the grain boundaries, and nanocrystal materials are known to be composed of equiaxed crystals surrounded by disordered grain boundaries.

The infrared absorption layer utilizes a semiconductor-type dopable nanocrystal material. For example, the infrared absorption layer is indium tin oxide (Sn:In2O3), tungsten oxide (WOx), molybdenum oxide (MoOx), zinc oxide (ZnO), titanium oxide (TiO2), aluminum oxide (Al2O3), vanadium oxide ( V2O3/VO2), hafnium oxide (HfO2), cerium oxide (CeO2), copper sulfide (CuSx), silicon nitride (SiN), and titanium nitride (TiN).

Hereinafter, a method for manufacturing an infrared absorption layer using plasmonic nanoparticles according to an embodiment of the present invention will be described.

Figure 6 is a flow chart for manufacturing an infrared absorption layer using plasmonic nanoparticles according to an embodiment of the present invention. Referring to Figure 6, the nanocrystal material is prepared (S110), and the nanocrystal material is prepared as a colloidal solution. (S120), nucleation-growth is performed using a nanoparticle synthesis technique (S130), and a doping element is injected into the solution to synthesize nanoparticles (S140). Thereafter, the synthesized nanoparticles are separated and purified and dispersed in a polar solution or a non-polar solution (S150) to prepare a plasmonic infrared absorption layer (S160).

In one embodiment of the present invention, doping elements of positive and negative ions are included to form semiconductor-type plasmonic nanoparticles. The cation is a group consisting of tin (Sn), zirconium (Zr), cerium (Ce), cesium (Cs), aluminum (Al), gallium (Ga), indium (In), tungsten (W), and molybdenum (Mo). and the anion is mainly a halogen anion and is at least one selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and the element vacancy.

In one embodiment of the present invention, the content of the doping element is limited to 15% or less. If the infrared absorption layer is manufactured including indium tin oxide (Sn:In2O3) and tungsten oxide (WOx), the indium tin oxide contains n-type doped tin (Sn) element in a weight ratio (x = 15% or less) of 15% or less. When composed of 0~15%), free electrons are generated within the nanoparticle crystal lattice, and the remaining ((100-x)%) is an indium oxide crystal component, which is strong as a supersonic material and has a crystal phase transition ( This is because it can be used without phase transformation. If the content of the doping element exceeds 15%, the material is defined as an alloy, and phase separation without forming free electrons may occur, which may lead to a decrease in infrared absorption performance. In other words, as the concentration of free electrons decreases, the peak shift of the localized surface plasmon resonance (LSPR) may red shift to a long wavelength region, which may lead to performance degradation, and thus, one implementation of the present invention The content of the doping element in the example is limited to 15% or less.

When nanoparticles are synthesized by injection of a doping element (S140), the synthesized nanoparticles are dispersed in a polar solution or non-polar solution (S150). If the synthesized nanoparticles are synthesized in a fat-soluble solution, they are dispersed in a non-polar solution, and the fat-soluble solution contains oleic acid, oleyl alcohol, octylamine, and trioctylamine. and one or more selected from the group containing Octadecene. The nonpolar solution at this time may be hexane or toluene.

In addition, when dispersing the synthesized nanoparticles in a polar solution, Meerwein salt containing Nitrosonium Tetrafluoroborate and Triethyloxonium Tetrafluoroborate is added before dispersing in the polar solution. Nanoparticles are surface treated using salt) or a basic aqueous solution containing sodium hydroxide (NaOH) and potassium hydroxide (KOH). In the surface treatment step, the concentration of the meervine salt or basic aqueous solution is preferably 80 to 120 mg/ml.

The plasmonic nanoparticles manufactured through the manufacturing process (S160) are manufactured in any one of the following shapes: spherical, cubic, polyhedral, or non-uniform.

Meanwhile, in one embodiment of the present invention, an infrared blocking optical filter 110 is manufactured using the infrared absorbing layer. For example, the infrared absorbing layer 101 is formed by spin coating or liquid-gas interface deposition. It can be manufactured by forming a single layer of nanoparticles on the substrate 101 through the -air interface deposition method. Furthermore, a multilayer structure of nanoparticles may be formed on the substrate 101 through spray coating or blade coating. In addition, before the nanoparticles are synthesized to form a polymer, the nanoparticles may be dispersed in a polar or non-polar solution and the solution in which the nanoparticles are dispersed may be added to the infrared absorption layer to be synthesized later to form a film composite. In other words, a film composite may be formed by dispersing nanoparticles in a polar solution or non-polar solution before the polymer polymer reaction and adding them to the infrared absorption layer 102, which is a subsequently polymerized polymer film.

By this method, an infrared blocking optical filter 110 using plasmonic nanoparticles can be formed, and this filter 110 can be formed on an automobile glass. That is, the filter 110 including the infrared absorption layer 102 can be attached to the glass of an automobile.

Hereinafter, the manufacturing process of the plasmonic infrared absorption layer according to an embodiment of the present invention will be described in more detail.

The production of a plasmonic infrared absorbing layer according to an embodiment of the present invention begins with the nanoparticle solution synthesis step. That is, to synthesize colloidal nanoparticles, nanoparticle powder is prepared into a solution and then synthesized.

Plasmonic nanoparticles utilize semiconductor-type doped nanocrystal materials. For example, the main nanoparticle materials of the plasmonic infrared absorption layer are indium tin oxide (Sn:In2O3) and tungsten oxide (WOx). However, molybdenum oxide (MoOx), zinc oxide (ZnO), titanium oxide (TiO2), aluminum oxide (Al2O3), vanadium oxide (V2O3/VO2), hafnium oxide (HfO2), cerium oxide (CeO2), copper sulfide (CuSx) ), infrared-absorbing nanomaterials such as silicon nitride (SiN), and titanium nitride (TiN) may also be included.

The appropriate concentration range of doping elements is 15% or less. Doping elements are combined to induce free electrons in the semiconductor through plasmonic implementation. Cations include tin (Sn), zirconium (Zr), cerium (Ce), cesium (Cs), aluminum (Al), gallium (Ga), and indium ( One or more of In), tungsten (W), and molybdenum (Mo) may be combined. Additionally, halogen anions are mainly used as anions, including fluorine (F), chlorine (Cl), and bromine (Br), and elemental vacancy can also be used.

Once the preparation of the nanocrystal material (S110) is completed, the particle material undergoes a nucleation-growth step (S130) using the colloidal nanoparticle synthesis technique, and a doping element is injected to form a polymer by synthesis (S140). . The appropriate range of doping activity is when the doping element is 5%, which is carried out at the concentration of Tin Acetate.

If nanoparticles are synthesized in a fat-soluble solution such as Oleic Acid, Oleyl Alcohol, Octylamine, Trioctylamine, or Octadecene, they are dispersed in a non-polar solution. This is possible. More specifically, indium acetate and tin acetate are polymerized with oleic acid at a temperature of 150°C to form indium oleate. The indium oleate is injected into Oleyl Alcohol at 290°C. At this time, the nanoparticles grow through synthesis, and the infrared absorption layer 102 is manufactured by separating and purifying the grown nanoparticles and dispersing them in a non-polar solution such as hexane or toluene. In order to manufacture the infrared absorption layer 102 in the form of a thin film, an infrared blocking filter 110 is created by spraying on a substrate 101 such as a glass film.

Meanwhile, when dispersing the nanoparticles in a polar solution, Meerwein Salt or basic aqueous solution is used. For example, Meerwein Salt containing Nitrosonium Tetrafluoroborate, Triethyloxonium Tetrafluoroborate, or basic salt containing sodium hydroxide (NaOH) and potassium hydroxide (KOH). Nanoparticles are surface treated using an aqueous solution.

For this purpose, approximately 100 mg/mL of meerbein salt or basic aqueous solution is added.

At this time, nanoparticles in the form of strips of organic ligands are dispersed in polar solutions such as water, aqueous solutions, alcohol-based solutions, dimethylformamide, acetonitrile, and polymers. It is possible, and thereby the infrared absorption layer 102 can be formed.

Figure 2 is a graph of an experiment to verify whether the infrared blocking function is maintained after applying a supersonic shock wave of nanoparticles according to an embodiment of the present invention. Referring to Figure 2, it can be seen that the infrared blocking function does not change significantly from 1 shock to 15 shocks at Mach 6. In other words, it can be seen that the infrared absorption layer absorbs infrared rays in the 5,000 to 3,000/cm wavenumber band despite multiple impacts.

The plasmonic nanoparticles in the infrared absorption layer 102 may be spherical, cube-shaped, polyhedral, or non-uniform. Figure 3 is a photograph of a spherical infrared-absorbing plasmonic particle according to an embodiment of the present invention, Figure 4 is a photograph of a cube-shaped infrared-absorbing plasmonic particle according to an embodiment of the present invention, and Figure 5 is an embodiment of the present invention. This is a photo of a non-uniform infrared absorbing plasmonic particle according to . Referring to Figures 3 to 5, the shape of the plasmonic nanoparticles can form a spherical cluster, cube- or square-shaped plasmonic nanoparticles can be formed by uniformly dispersing, and polyhedral, circular, etc. plasmonic nanoparticles can be formed. They may be overlapped and formed evenly.

The difference in absorbance per unit particle of the spherical, cube-shaped and heterogeneous plasmonic nanoparticles is not large. However, the theoretical packing density of spherical nanoparticles is 74%, and that of cube-shaped nanoparticles is 100%, so it can be said that cube-shaped particles have a greater expected effect of enhancing light absorption per unit area of the film.

Meanwhile, an infrared absorption layer 102 is formed dispersed in a polar solution or a non-polar solution. When the infrared absorption layer 102 has a small area in the form of a film thin film, it is possible to form a single layer of nanoparticles through spin coating or liquid-air interface deposition. In the case of large-scale manufacturing, the infrared absorption layer 102 with a multilayer nanoparticle structure can be formed by spray coating or blade coating on the substrate 101. The base material 101 at this time may be glass. At this time, if the nanoparticles are formed as a single layer, the number of particles per unit area decreases and the absorbance decreases, but if they are formed as a multilayer, the absorbance can be increased.

Figure 7 is a schematic diagram illustrating the supplementation of the blind spot angle caused by sunlight with an optical filter attached to the infrared detector of a supersonic aircraft according to an embodiment of the present invention, showing the area (β1 + α + β2) blocked by infrared sunlight. ) is shown expanded by the optical filter 110 for infrared detection attached to the supersonic vehicle 100. Referring to FIG. 7, conventionally, the blind spot angle of the infrared detector of the supersonic vehicle 100 with respect to the vehicle 10 approaching at supersonic speed was (β1+α+β2), but the plasmonic infrared absorption layer according to an embodiment of the present invention When the optical filter 110 using is attached, it can be seen that the angle of the solar blind spot is reduced to α. That is, the angle of the conventional solar blind spot was in the green area, but in one embodiment of the present invention, the angle of the solar blind spot was reduced to the red area. The yellow area is an area where solar infrared rays are not blocked and is an area where infrared tracking for the supersonic aircraft 10 is possible even conventionally.

In order to increase the effect of blocking solar infrared rays, the blind spot angle must be minimized by increasing the absorbance of the film. In one embodiment of the present invention, the absorbance per nanoparticle is maximized by controlling the doping component and content ratio to maximize the number of free electrons. increased.

In this way, the supersonic aircraft 100 in which the infrared absorption layer 102 using plasmonic nanoparticles according to an embodiment of the present invention is attached to the infrared sensor can have a wider infrared heat detection angle.

The description of the present invention described above is for illustrative purposes, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. will be. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. For example, each component described as single may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the patent claims described below, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

100: supersonic aircraft, 110: infrared blocking optical filter

Claims (10)

matrix; and
Formed on the substrate and comprising an infrared absorption layer manufactured using a nanocrystal material capable of semiconductor type doping,
Infrared blocking optical filter using plasmonic nanoparticles applicable to hypersonic flow.
In claim 1,
The infrared absorption layer is,
Indium tin oxide (Sn:In2O3), tungsten oxide (WOx), molybdenum oxide (MoOx), zinc oxide (ZnO), titanium oxide (TiO2), aluminum oxide (Al2O3), vanadium oxide (V2O3/VO2), hafnium oxide ( HfO2), cerium oxide (CeO2), copper sulfide (CuSx), silicon nitride (SiN), and titanium nitride (TiN),
Infrared blocking optical filter using plasmonic nanoparticles applicable to hypersonic flow.
In claim 1,
The doping element for the semiconductor type doping is,
Characterized in that 15% or less is injected into the nanocrystal material,
Infrared blocking optical filter using plasmonic nanoparticles applicable to hypersonic flow.
In claim 3,
The doping element is,
selected from the group consisting of tin (Sn), zirconium (Zr), cerium (Ce), cesium (Cs), aluminum (Al), gallium (Ga), indium (In), tungsten (W), and molybdenum (Mo). Characterized in that it contains one or more cations,
Infrared blocking optical filter using plasmonic nanoparticles applicable to hypersonic flow.
In claim 3,
The doping element is,
Characterized in that it contains one or more anions selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and elemental vacancy,
Infrared blocking optical filter using plasmonic nanoparticles applicable to hypersonic flow.
In claim 1,
The infrared absorption layer is characterized in that it absorbs infrared rays in the wavelength range of 5,000 to 3,000/cm,
Infrared blocking optical filter using plasmonic nanoparticles applicable to hypersonic flow.
In claim 1,
The shape of the plasmonic nanoparticle is characterized in that it is any one of spherical, cubic, polyhedral, or heterogeneous shape.
Infrared blocking optical filter using plasmonic nanoparticles applicable to hypersonic flow.
In claim 1,
The infrared absorption layer is,
Characterized in that it is formed as a single layer of nanoparticles through spin coating or liquid-air interface deposition.
Infrared blocking optical filter using plasmonic nanoparticles applicable to hypersonic flow.
In claim 1,
The infrared absorption layer is,
Characterized in that it is formed into a multilayer structure of nanoparticles through spray coating or blade coating.
Infrared blocking optical filter using plasmonic nanoparticles applicable to hypersonic flow.
In claim 1,
Characterized in that the substrate is automobile glass,
Infrared blocking optical filter using plasmonic nanoparticles applicable to hypersonic flow.