KR102202491B1 - METHOD FOR CONFIGURATING PLATINUM NANOPARTICLES VIA DEWETTING EHANCED SOLID STATE OF In-Pt BILAYERS - Google Patents

Abstract

The present invention is to provide a method for constructing platinum nanoparticles (Pt NPs) capable of generating localized surface plasmons with improved composition, arrangement, and uniformity of Pt NPs. According to an embodiment of the present invention, a method for constructing Pt NPs through dewetting of a solid-state indium-platinum (In-Pt) double layer comprises the steps of: dicing and degassing a substrate in a pulsed laser deposition (PLD) chamber; depositing the degassed substrate as a double layer of In-Pt in a sputter chamber; relocating a substrate on which the In-Pt double layer is deposited to the PLD chamber so that the substrate on which the In-Pt double layer is deposited is annealed; and dewetting the substrate on which the In-Pt double layer is deposited in the PLD chamber.

Description

Method of constructing platinum nanoparticles through dewetting on solid indium-platinum (In-Pt) double layers{METHOD FOR CONFIGURATING PLATINUM NANOPARTICLES VIA DEWETTING EHANCED SOLID STATE OF In-Pt BILAYERS}

The present invention relates to a method of forming platinum nanoparticles through dewetting on a solid indium-platinum (In-Pt) double layer, and more specifically, indium (In) and platinum ( It relates to a method of configuring various platinum nanoparticles by controlling the thickness of the Pt) thin film layer, respectively.

Recently, based on research on a noble metallic nanostructure, it has been proven that the field of plasmon and photoelectron technology can be applied industrially.

In the field of medical, biological, and electrical energy storage technology, the dimensions, composition, arrangement and uniformity of nanoparticles (NP) constituting the precious metal nanostructure are considered for each technical field, and the optical, catalytic, and magnetic fields required for each field are considered. And noble metal nanostructures having electronic properties are being commercialized.

The interaction between the metal and the electromagnetic wave is mainly described by the behavior of free electrons inside the metal, and plasmon plays a very important role in the optical properties of the metal.

Surface plasmon refers to the collective vibration of free electrons on a metal surface, and localized surface plasmon is a surface that exists on the surface of a metal nanostructure such as NanoParticles (NP). Means plasmon.

Localized surface plasmon can be easily excited (excitation, a state in which the energy level of electrons is increased) by incident light, which is called localized surface plasmon resonance (LSPR).

When local surface plasmon resonance (LSPR) occurs, the electric field of incident light is strongly amplified near the nanostructure surface, and light absorption and scattering are greatly increased.

The wavelength, bandwidth, and peak position of light that generates local surface plasmon resonance (LSPR) are determined by a function that considers all of the material, size, shape, arrangement, geometry, and surrounding environment of the nanoparticle (NP). The function can be tuned by controlling the structural factors of the plasmon nanoparticles.

Gold (Au) and silver (Ag) are representative materials that exhibit excellent plasmon properties, and many studies have been made to improve the efficiency of solar cells by using nanoparticles (NP) or nanostructures of these materials.

Nanoparticles (NPs) of gold (Au) have a large surface-to-volume ratio of plasmon properties.

For example, when the power conversion efficiency of a solar cell is increased by using the plasmon characteristics of gold (Au), it can be greatly improved by adjusting the absorption wavelength by adjusting the particle size of gold nanoparticles (Au NP).

This efficiency conversion is largely due to two phenomena.

One is because light absorption can be increased due to the amplification of the electric field around gold nanoparticles (Au NP), and the other is that the optical path of light is increased due to scattering by gold nanoparticles (Au NP). This is because there is an effect of increasing the optical thickness of the light absorbing layer.

Both of these phenomena have the effect of ultimately increasing the light harvesting of the solar cell, and if more charges are generated in the absorption layer due to the increase of light harvesting, this may improve the current density and energy conversion efficiency of the solar cell.

As described above, intensive studies have been conducted on local surface plasmon resonance (LSPR) for the arrangement of silver (Ag) and gold (Au) nanoparticles and the interaction of metal, dielectric, or semiconductor active layers.

In addition, when visible light is irradiated to platinum (Pt), platinum nanoparticles (Pt NP) absorb photons, so platinum nanoparticles (Pt NP) of 10 nm or less are used to improve photocurrent and photocatalytic activity in redox reactions.

However, the plasmon characteristics of platinum (Pt) contained in precious metals, such as silver (Ag) and gold (Au), are rarely explored at present.

This was because the manufacturing process of platinum nanoparticles (Pt NP) was difficult.

이상의 높은 온도에서 디웨팅 공정을 수행할 필요가 있었다.That is, the platinum (Pt) atom has a lower diffusivity than silver (Ag) and gold (Au), and has more limited morphological and structural homogeneity than silver (Ag) and gold (Au), so that platinum nanoparticles (Pt NP) 800 to generate

It was necessary to perform the dewetting process at the higher temperature.

Because of the process performed at such a high temperature, the process of physically depositing or annealing platinum on a substrate has been complicated and difficult in reality.

A technology for manufacturing a composite using platinum nanoparticles has been disclosed in Korean Patent Application Publication No. 10-2018-0105057.

Republic of Korea Patent Publication No. 10-2018-0105057

An object of the present invention is to improve the above-described problems, and to provide a method of constructing platinum nanoparticles capable of generating local surface plasmons with improved configuration, arrangement and uniformity of platinum nanoparticles (Pt NP).

In addition, the present invention is to improve the above-described problems, and to provide a method of constructing platinum nanoparticles that enables the process of generating platinum nanoparticles to proceed at a lower temperature than the conventional method of constructing platinum nanoparticles. have.

In order to achieve the above object, the present invention is a step in which a substrate is diced and degassed in a pulsed laser deposition chamber (PLD), and the degassed substrate is deposited as a double layer of indium-platinum in a sputter chamber. The step of, relocating the substrate on which the double layer of indium-platinum is deposited is rearranged in the pulsed laser deposition chamber to anneal the substrate on which the double layer of indium-platinum is deposited, and the indium- It provides a method for constructing platinum nanoparticles through dewetting on a solid state indium-platinum (In-Pt) double layer, comprising the step of dewetting a substrate on which a double layer of platinum is deposited.

의 조건으로 설정되고, 이러한 조건하에서 상기 기판이 30분 동안 상기 펄스 레이저 증착 챔버 내부에 유지되는 제A 단계를 더 포함할 수 있다.In the dicing and degassing step, the inside of the pulsed laser deposition chamber is 1Х10 ^-4 Torr and 600

It is set to the condition of, and under such conditions, the substrate may further include step A in which the substrate is maintained in the pulsed laser deposition chamber for 30 minutes.

Prior to the dicing and degassing step, the step of polishing both sides of the substrate to a thickness of ~430 μm may be further included.

The substrate may be composed of a C-plane sapphire offset by ±0.1°.

Sapphire of 99.999% purity may be used as the substrate.

The depositing may further include a step B in which the inside of the sputter chamber is set to 1×10 ^-1 Torr.

The depositing step includes the step C of depositing each thin film in the order of indium (In) and platinum (Pt) on a substrate at a deposition rate of 0.05 nm/s at 5 mA ionization current, and the indium (In) and platinum (Pt ) Further comprising a D step of controlling the deposition time in minutes, wherein the D step includes controlling the deposition time of indium (In) and the deposition time of platinum (Pt), respectively, and the indium ( In) and platinum (Pt) thin film thickness can be adjusted respectively.

The D step is a step D-1 of controlling the deposition time of indium (In) and the deposition time of platinum (Pt) so that a 5 nm of platinum (Pt) layer is deposited on a 5 nm of indium (In) layer. It may further include.

The D step is a step D-2 of respectively controlling the deposition time of indium (In) and the deposition time of platinum (Pt) so that a 5 nm platinum (Pt) layer is deposited on a 15 nm indium (In) layer. It may further include.

The D step is a step D-3 of respectively controlling a time for depositing indium (In) and a time for depositing platinum (Pt) so that a 15 nm platinum (Pt) layer is deposited on a 5 nm indium (In) layer. It may further include.

The annealing step may further include a step E of lowering the pressure inside the pulsed laser deposition chamber to 1Х10 ^-4 Torr or less.

The annealing step includes the step F of increasing the temperature inside the pulsed laser deposition chamber at a temperature increase rate of 4°C sec ^-1 and a specific target temperature between 550°C and 900°C in the pulsed laser deposition chamber It may further include a Gth step of reaching.

After the G-th step, the H-th step of maintaining the substrate in the pulsed laser deposition chamber for 450 seconds may be further included.

In the annealing step, the annealing may be controlled by a computer program.

After the dewetting step, further comprising the step of stopping the operation of the heating system so that the temperature inside the pulsed laser deposition chamber is lowered, the step of stopping the operation of the heating system, the vacuum inside the pulsed laser deposition chamber The state of the vacuum state inside the pulsed laser deposition chamber in the dewetting step may be maintained, and the temperature may be lowered by naturally cooling the inside of the pulsed laser deposition chamber with the passage of time by the atmosphere.

The method of forming platinum nanoparticles (Pt NP) by performing dewetting on a solid-state indium-platinum (In-Pt) double layer according to the present invention is a method of forming platinum nanoparticles (Pt NP), due to the indium (In) component. The efficiency of the dewetting) process is remarkably improved, and platinum nanoparticles (Pt NP) and substrates with improved diffusivity and distribution uniformity to a specific substrate surface can be produced and manufactured.

In addition, the method of constructing platinum nanoparticles (Pt NP) by performing dewetting on a solid indium-platinum (In-Pt) double layer according to the present invention is a conventional method of forming a platinum (Pt) thin film. Compared with the method of generating platinum nanoparticles through dewetting on a substrate, the branches can produce platinum nanoparticles (Pt NP) having a more independent, uniform, and hemispherical shape at a lower temperature.

FIG. 1 is a flowchart sequentially showing a manufacturing process of platinum nanoparticles produced on sapphire 10 from a double layer of indium-platinum (In-Pt) according to the present invention.
FIG. 2 is a flowchart of a process included in a method of constructing platinum nanoparticles through dewetting on a solid indium-platinum (In-Pt) double layer according to the present invention.
3 is an AFM plan view, an AFM side view, a cross-sectional line-profile, and graphs obtained by measuring and analyzing the composition of platinum nanoparticles according to the first embodiment of the present invention.
4 is a histogram of the size distribution of platinum nanoparticles according to the first embodiment of the present invention.
5 are graphs showing optical properties of platinum nanoparticles according to the first embodiment of the present invention.
FIG. 6 is an AFM plan view, an AFM side view, a cross-sectional line-profile, and graphs obtained by measuring and analyzing the composition of platinum nanoparticles according to the second embodiment of the present invention.
7 is a histogram of a size distribution of platinum nanoparticles according to a second embodiment of the present invention.
8 are graphs showing optical properties of platinum nanoparticles according to a second embodiment of the present invention.
9 is an AFM plan view, an AFM side view, a cross-sectional line-profile and graphs obtained by measuring and analyzing the composition of platinum nanoparticles according to the third embodiment of the present invention.
10 are graphs showing optical properties of platinum nanoparticles according to a third embodiment of the present invention.

All the embodiments described below are illustratively shown to aid understanding of the present invention, and may be modified differently from the embodiments described herein to be implemented in various embodiments. In addition, in describing the present invention, when it is determined that a detailed description of a related known function or known component may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

The accompanying drawings are not drawn to scale to aid understanding of the invention, but dimensions of some components may be shown exaggeratedly, and when reference numerals are given for each component, other drawings for the same components Even if it is indicated in, it is indicated with the same symbol as possible.

In addition, terms such as first, second, A, B, (a), and (b) may be used in describing the constituent elements of the embodiment of the present invention. These terms are only used to distinguish the component from other components, and the nature, order, or order of the component is not limited by the term. When a component is described as being'connected','coupled' or'connected' to another component, the component may be directly connected, coupled or connected to the other component, but that component and its other components It will be understood that another component may be'connected','coupled' or'connected' between elements.

Accordingly, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all the technical ideas of the present invention, so there may be various modified embodiments of the present invention. .

In addition, terms or words used in the present specification and claims should not be limited to conventional or dictionary meanings, and that the inventor may appropriately define the concept of terms in order to describe his own invention in the best way. Based on the principle, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention.

In addition, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only these embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have it, and the invention is only defined by the scope of the claims.

In addition, the singular expression used in the present application includes a plural expression unless the context clearly indicates otherwise.

Hereinafter, a method of constructing platinum nanoparticles through dewetting on a solid indium-platinum (In-Pt) double layer will be described in detail with reference to FIGS. 1 and 2.

1 is a flow chart showing in sequence the manufacturing process of platinum nanoparticles produced on sapphire 10 from a double layer of indium-platinum (In-Pt) according to the present invention, and FIG. 2 is a solid state according to the present invention. It is a flow chart of a process included in a method of constructing platinum nanoparticles through dewetting on an indium-platinum (In-Pt) double layer.

In the present invention, sapphire 10 is used as a substrate.

First, after sputtering the solid-state indium-platinum bilayers (In-Pt bilayers) strengthened on the sapphire 10, dewetting for these indium-platinum bilayers (In-Pt bilayers) ).

The present invention is a platinum nanoparticle (Pt NanoParticle, Pt NP), a platinum nanostructure (Pt Nanomatrix), and a platinum nanostructure (Pt NP) having an improved size, a distinct shape, and a uniform shape compared to the prior art through such a method. Nanostructure) is created and formed.

Meanwhile, as a term used in the present invention, dewetting is a phenomenon in which a thin film in a liquid phase is ruptured on a substrate and changes into droplets (metal droplets or volumes), or inducing such a phenomenon. I mean fair.

This is a concept opposite to a wetting phenomenon in which a droplet dropped on a substrate spreads widely to form a thin film.

Dewetting of the metal thin film in the molten state is affected by many factors including the initial thickness and structure of the metal thin film, but the driving force is the overall energy of the metal thin film and the surface of the substrate and its interface. It is to minimize it.

Dewetting of a metal thin film can be performed by various methods such as high-temperature heat treatment, irradiation of electrons or ion beams, and laser irradiation, and conventional dewetting has been mainly performed on a silicon or glass substrate.

However, in the present invention, as shown in FIG. 1, the process is performed on a sapphire wafer 10 (hereinafter referred to as sapphire).

In the present invention, a 430 μm-thick C-plane sapphire 10 that is off the ±0.1° axis and polished on both sides was used as a substrate.

However, the use of the sapphire 10 as a substrate in the present invention is only an exemplary case and does not limit the use of other materials as a substrate, and the deposition and dewetting process of the double layer according to the present invention is silicon or glass. This includes running on the substrate.

However, sapphire 10 has low surface energy, high thermal and chemical stability, and has high internal diffusion resistance, so that the effect of the method according to the present invention is markedly compared to the method of constructing the conventional platinum nanoparticles. Can be indicated.

In addition, since the sapphire 10 has high transparency, when a local surface plasmon resonance phenomenon occurs, the transmittance of the platinum nanoparticles can be directly measured, so that the optical properties or optical response of the platinum nanoparticles (Pt NP) can be more effectively improved. It is a substrate that can be irradiated and detected.

Accordingly, in the following, all embodiments of the present invention will be described as using sapphire 10 as a substrate. However, it has already been described that this description is not limited to the deposition and dewetting process of the present invention being performed on the sapphire 10 only.

2, the sapphire 10 is diced in a pulse laser deposition (PLD) chamber at 1×10 ^-4 Torr and 600° C. for 30 minutes and degassed. The gas is removed) (S1010).

Since the surface shape, reflectance, and transmittance of the pure sapphire 10 are already known, detailed descriptions are omitted.

The degassed sapphire 10 is a substrate on which an indium-platinum (In-Pt) double layer is deposited, and is used for manufacturing platinum nanoparticles, and is then moved to a sputter chamber for double layer deposition.

Meanwhile, as shown in FIG. 1, when the sapphire 10 is disposed in the sputter chamber, an indium (In) layer and a platinum (pt) layer are respectively deposited on the sapphire 10, so that the indium (In) layer is platinum. A double layer of indium-platinum (In-Pt) positioned under the (Pt) layer is formed (S1020).

More specifically, an indium (In) layer is first deposited on the sapphire 10 on the sapphire 10 located inside the sputter chamber using a sputtering method, which is a type of vacuum deposition, A platinum (pt) layer is deposited on the deposited indium (In) layer.

At this time, the sputter chamber in which the indium-platinum (In-Pt) double layer deposition process is performed maintains a vacuum state of 1×10 ⁻¹ Torr.

In addition, during sputtering, sapphire 10 having a purity of 99.999% is used as a target.

The indium-platinum (In-Pt) double-layer deposition process performed in the sputter chamber is performed at a deposition rate of 0.05 nm/s at 5 mA ionization current, and each of indium (In) and platinum (Pt) in the order of sapphire (10). The layer is deposited, and the deposited thickness is controlled by controlling the time taken for the deposition of each atom (indium and platinum).

In this way, a substrate in which indium (In) and platinum (Pt) are deposited, a substrate on which a double layer of indium-platinum (In-Pt) is deposited, an alloy layer of indium-platinum (In-Pt), or an indium-platinum ( It may be referred to as sapphire 10 on which a double layer of In-Pt) is deposited.

Meanwhile, the sapphire 10 on which the double layer of indium-platinum (In-Pt) is deposited is rearranged in the pulsed laser deposition chamber to perform an annealing process. Then, the sapphire 10 on which the double layer of indium-platinum (In-Pt) is deposited is annealed while passing through specific temperatures (S1030).

In the annealing process of the present invention, an indium-platinum (In-Pt) double layer is formed by inter-atomic mixing due to mutual diffusion of indium (In) and platinum (Pt) atoms at the interface.

That is, the indium (In) thin film layer and the platinum (Pt) thin film layer deposited on the sapphire (10) substrate undergo an annealing process, and the indium (In) thin film layer and platinum sputtered on the sapphire (10) The (Pt) thin film layer is a layer adjacent to each other, while diffusing indium (In) and platinum (pt) atoms to each other, and forming a solid-state indium-platinum (In-Pt) alloy and an indium-platinum (In-Pt) double layer. To form.

The indium (In) atom is activated at a temperature relatively lower than that of the platinum (Pt) atom and begins to diffuse. As shown in Fig. 1(b), indium at the interface between the indium (In) thin film layer and the platinum (Pt) thin film layer (In) atoms are diffused and mixed into the platinum (Pt) thin film layer, resulting in an interdiffusion phenomenon between the two thin film layers.

In addition, in the present invention, as the deposition temperature increases, a eutectic mixture may be formed at the indium-platinum (In-Pt) interface at a lower temperature during the annealing process, and the formation of an indium-platinum double layer or alloy due to the eutectic mixture The interdiffusion of atoms leading to alloy formation can be further promoted.

On the other hand, in all embodiments of the present invention, in order to clarify that the factor affecting the generation of platinum nanoparticles lies in controlling the thickness of the indium (In) layer and/or the platinum (Pt) layer, the overall annealing process is the same and It is controlled by a consistent computer program.

In particular, the annealing process controlled by a computer program ends the growth of platinum nanoparticles, until the temperature inside the pulsed laser deposition chamber is cooled down to a certain value or less by the atmosphere over time. It is configured to turn off the heating system while maintaining the same pressure in the vacuum state.

Meanwhile, after completing the annealing process, the sapphire 10 on which the double layer of indium-platinum (In-Pt) is formed is dewetted in the pulse laser deposition chamber (S1040).

The sapphire 10 on which the indium-platinum (In-Pt) double layer is deposited according to all embodiments of the present invention is maintained for 450 seconds in the pulse laser deposition chamber, and the inside of the pulse laser deposition chamber is at a specific target temperature. Upon reaching that temperature, the temperature is maintained for 450 seconds.

In addition, the specific target temperature here is a specific temperature included in the range of 550°C to 900°C, and may vary between 550°C and 900°C according to the annealing and dewetting processes included in each embodiment.

In this case, indium (In) is used as a sacrificial metal in In-Pt bilayers.

This is because indium (In) has a higher diffusivity than platinum (Pt), and indium (In) has a lower surface energy and a lower sublimation temperature than platinum (Pt).

In other words, platinum (Pt) has a higher surface energy than indium (In), so it has a higher melting point (1768℃) than indium (In), whereas indium (In) has a lower surface energy than platinum (Pt). Therefore, the melting point (156.6℃) is lower than that of platinum (Pt).

On the other hand, the sacrificial metal here refers to a sacrificial metal used for self-sacrificial corrosion, which instead corrodes other metals to prevent corrosion of a specific metal, and is more easily oxidized than a specific metal to prevent corrosion. The resulting metal is called a sacrificial metal.

Hereinafter, indium (In) used as a sacrificial metal in the present invention may also be referred to as sacrificial in.

Therefore, in the present invention, during the dewetting process for indium-platinum bilayers, indium (In) atoms are sublimated at a relatively low temperature compared to platinum (Pt) atoms, and thus indium-platinum nanoparticles at the interface Indium (In) is preferentially removed from the matrix (In-Pt Nano Particle Matrix).

In general, metal thin films such as indium (In) thin films and platinum (Pt) thin films are not stable in a short time after being deposited. Therefore, when appropriate thermal energy is applied to the metal thin film, it is transformed into isolated particles or dewetting ( dewetting).

The transformation of these metallic thin films is mainly achieved by minimizing the total energy of the thermodynamic system.

During the dewetting process for the indium-platinum bilayers according to the present invention, the indium (In) layer has higher diffusivity and higher vapor pressure than the platinum (Pt) layer, so that the conventional platinum (Pt ) Compared to the case of performing the dewetting process on a single layer, the dewetting efficiency for a platinum (Pt) thin film is improved overall.

In the dewetting process for indium-platinum bilayers according to the present invention, a platinum nano matrix is grown and formed through the following process.

(i) mutual diffusion of indium (In) and platinum (Pt) atoms at the interface,

(ii) formation of an indium-platinum (In-Pt) binary system,

(iii) partial local dewetting of indium-platinum (In-Pt) alloy thin films,

(iv) sublimation of the indium (In) atom, and

(v) Generation of almost pure platinum nano-structures (Pt nano matrix).

More specifically, in relation to the diffusivity, surface energy, melting temperature, thickness of the sacrificial In layer and the platinum (Pt) thin film layer adjacent to the sacrificial In layer, such as mutual atomic diffusion. Due to the factors, the dewetting process for the indium-platinum (In-Pt) double layer according to the present invention improves the overall dewetting efficiency compared to the case of performing the dewetting process on a conventional platinum (Pt) single layer. do.

Therefore, the mutual atomic diffusion between the indium-platinum (In-Pt) double layers and the formation of the indium-platinum (In-Pt) alloy improve the diffusibility of the entire indium-platinum (In-Pt) double layer and reduce the dewetting process. It is the most important factor to promote.

In case of performing local dewetting on the indium-platinum (In-Pt) double layer, as depicted in Fig. 1(c), the indium-platinum due to improved surface diffusivity as the temperature inside the chamber increases. (In-Pt) alloy formation can be further promoted.

At this time, voids, pits, and some large indium-platinum (In-Pt) aggregates are formed on the surface of the double layer by the high temperature inside the chamber.

In addition, as shown in (d) of FIG. 1, while continuing dewetting, an indium (In) atom having an evaporation temperature lower than that of a platinum (Pt) atom is a platinum (Pt) atom on the sapphire 10 It is sublimated earlier, resulting in an almost pure Pt nano matrix.

In this way, the dewetting process for the indium-platinum bilayers according to the present invention is by using a sacrificial indium (In) layer, in contrast to the conventional dewetting process on a pure platinum (Pt) thin film The efficiency of the dewetting process can be improved, and the shape of the platinum nanoparticles can be more effectively controlled when forming the platinum nanoparticles.

In particular, the dewetting process for the indium-platinum bilayers according to the present invention can change the shape of the platinum nanoparticles by forming the indium-platinum (In-Pt) bilayer film with different thicknesses. have.

Hereinafter, a method of configuring platinum nanoparticles according to a first embodiment of the present invention will be described with reference to FIGS. 3 to 5. In addition, the shape and characteristics of the platinum nanoparticles produced by the dewetting process according to the first embodiment and the method according to the first embodiment will be described in detail.

The surface morphology of the platinum nanostructure (Pt NP) generated and produced in all examples as well as this example was an atomic force microscope (AFM) (XE-70, Park Systems, South Korea) and a scanning electron microscope ( It was photographed with a Scanning Electron Microscope, SEM) (CoXEM, South Korea), and a large-scale surface shape was analyzed.

Atomic force microscopy (AFM) scanning was performed in a non-contact mode using a batch of tips with a radius of curvature <10 nm, a force constant of 40 nm ^-1 , and a resonance frequency of ~300 kHz.

In order to explain the detailed structural and dimensional evolution of nanostructures in not only this embodiment, but also in all examples, a top view, a side view, a cross-section-line profile, a surface area to volume ratio (SAR), and a surface roughness, RMS) was statistically represented using the roughness parameter Rq.

In addition, for atomic properties and spectral mapping in all examples as well as this example, analysis was performed with an energy dispersive x-ray spectroscope (EDS) (Thermo Fisher, Noran System 7, USA). I did.

On the other hand, optical properties such as reflectance measurement in all embodiments as well as this embodiment, ANDOR sr-500i spectrograph (Oxford Instruments, United Kingdom), a CCD detector, and a UNIRAM II system equipped with various optical devices (UniNanoTech Co. Ltd.) , South Korea).

In addition, as a light source including ultraviolet (UV), visible (VIS), and near-infrared (NIR) regions of the electromagnetic spectrum, as well as in this embodiment, using halogen and deuterium lamps (OCEAN optics, United Kingdom), nano The particles were excited.

In the drawing, inset represents a graph of transmittance measured in each step of the process.

3 is an AFM plan view, an AFM side view, a cross-sectional line-profile and graphs measured and analyzed for each temperature of the composition of platinum nanoparticles according to the first embodiment of the present invention, and FIG. 4 is a first embodiment of the present invention. Is a histogram of the size distribution of platinum nanoparticles, and FIG. 5 is a graph showing optical properties of the platinum nanoparticles according to the first embodiment of the present invention.

Referring to FIG. 3, in the method of constructing platinum nanoparticles according to the first embodiment of the present invention, a 5 nm platinum (Pt) layer is deposited on a 5 nm indium (In) layer, and'In _{5 nm} /Pt _{5 nm} bilayer' It is represented by

The sapphire 10 according to the first embodiment of the present invention is first diced and degassed inside the pulsed laser deposition chamber (S1010), and then transferred to the sputtering chamber.

In the sputter chamber, an indium (In) thin film layer having a thickness of 5 nm and a platinum (Pt) thin film layer having a thickness of 5 nm are sequentially deposited on the sapphire 10 (S1020).

The sapphire 10 on which the indium-platinum (In-Pt) double layer is deposited is then transferred back to a pulsed laser deposition (PLD) chamber to undergo an annealing process (S1030).

During the annealing process, the internal pressure of the pulsed laser deposition chamber is maintained below 1Х10 ^-4 Torr, and the internal temperature of the pulsed laser deposition chamber is 4℃ sec ^-1 to reach a target temperature between 550℃ and 900℃. The temperature rises at the rate of temperature rise.

On the other hand, after completing the annealing process, the sapphire 10 on which the double layer of indium-platinum (In-Pt) is formed is dewetted for 450 seconds at a specific temperature present between 550°C and 900°C in the pulse laser deposition chamber, It is dewetted from 550°C to 900°C while increasing the temperature (S1040).

Referring back to FIG. 3, from a double layer in which a 5 nm-thick indium (In) thin film layer and a 5 nm-thick platinum (Pt) thin film layer are formed, generated through annealing performed at a specific target temperature between 550° C. and 900° C. You can see platinum nanoparticles (Pt NP).

First, as shown in (a) of FIG. 3, a 5 nm-thick indium (In) thin film layer was deposited on the sapphire 10, and a 5 nm-thick platinum (Pt) thin film layer was deposited on the indium (In) thin film layer. Deposited.

Referring to the AFM plan view (b) to the AFM plan view (i) of FIG. 3, in this embodiment, at a relatively low temperature of 550° C., a void is formed on the surface of the sapphire 10 and irregular platinum nanoclusters (Pt Platinum nanostructures including nano clusters (platinum nano clusters) begin to form, and as the temperature gradually increases to 900°C, hemispherical platinum nanoparticles (Pt NP) isolated from each other are generated.

Referring to the AFM plan view (b) of FIG. 3, when the temperature is 550°C, platinum nanoclusters are irregularly arranged, but relatively independent platinum nanoparticles (Pt NP) are already generated on the surface of the sapphire 10 Indicates that there is.

The average size of the platinum nanoparticles (Pt NP) thus formed is -58 nm in diameter and -10 nm in height, as shown in the AFM side view (b-1) and cross-sectional line-profile (b-2) of FIG. 3. .

In addition, the size distribution histogram of the platinum nanoparticles (Pt NPs) shown in (a) and (a-1) of FIG. 4 shows the change in diameter and height of the platinum nanoparticles (Pt NPs) at a specific temperature.

Meanwhile, as the interdiffusion of indium (In) and platinum (Pt) atoms increases, the dewetting process starts, and in particular, pin holes and voids at low energy sites. The creation of a void nucleation is caused and the accumulation of atoms through the void rim is caused.

Referring to the AFM plan view (b) to the AFM plan view (i) of FIG. 3, as a result, the size, shape, and spacing between the nanoparticles of the platinum nanoparticles (Pt NPs) formed according to the first embodiment of the present invention are temperature It gradually improved with the rise of, which is a result of the sublimation of the indium (In) atom and the diffusion of the platinum (pt) atom on the surface of the sapphire 10 a lot.

에서 백금 나노 입자의 높이는 ~15nm 내지 25nm이고, 직경은 ~70nm 내지 90nm로 현저히 증가한다. First, looking at the AFM side view (d-1) and the cross-sectional line-profile (d-2) of FIG. 3, 650

In the height of the platinum nanoparticles is ~15nm to 25nm, the diameter is significantly increased to ~70nm to 90nm.

However, the density of the platinum nanoparticles according to this embodiment shows a remarkable decrease.

And, as shown in the AFM plan view (d) of FIG. 3, the nanostructure is formed somewhat irregularly long.

This is because the increase or decrease of the spacing between the platinum nanoparticles is determined depending on how much the interfacial energy between the metal thin film layer and the sapphire 10 is minimized, and the growth of voids is determined.

In addition, as can be seen in the AFM top view (f) and AFM top view (i) of FIG. 3, as the temperature increases from 750° C. to 900° C., the spacing between the platinum nanoparticles widens, and all of them have a uniform shape, It can be seen that this is improved.

Meanwhile, as the temperature increases, the randomly dispersed small platinum nanoparticles adhere to the platinum nanoparticles larger than themselves due to the adhesion phenomenon between the platinum nanoparticles, thereby decreasing their density and increasing their size.

And as the separated platinum nanoparticles adhere and grow, a more stable and large-sized platinum nanoparticle array is created.

The cross-sectional-line profiles shown in (f-2) to (i-2) of FIG. 3 show hemispherical platinum nanoparticles (Pt NPs) generated due to the isotropic surface energy distribution of the platinum nanoparticles.

Although the height of the hemispherical platinum nanoparticles according to the present embodiment increased significantly to ~30nm, the diameter was only slightly changed to ~80nm, but there was no significant change.

Under conditions similar to the conventional method of constructing platinum nanoparticles, a platinum thin film layer having a thickness of 5 nm and annealing temperature conditions, the method of constructing platinum nanoparticles according to the first embodiment of the present invention is a method of constructing platinum nanoparticles (Pt NP). It clearly shows that the size has been improved, the uniformity has been increased, and a uniform gap is formed between the particles.

In the conventional method of depositing only a platinum (Pt) thin film and then dewetting it to form a platinum nanostructure, the generation of void nuclei was observed only above 700℃, and even if the temperature change reached 900℃, platinum The size, uniformity and spacing between particles of the nanoparticles hardly changed.

However, the total size distribution of platinum nanoparticles (Pt NPs) formed according to the first embodiment of the present invention is as shown in FIG. 4, and their average height and diameter gradually increased with the increase in temperature. Is showing.

In addition, as shown in FIG. 4, it can be seen that the uniformity of the platinum nanoparticles is also improved as the temperature increases.

As described above, in the first embodiment of the present invention, a sacrificial in layer was introduced between the platinum (Pt) thin film layer and the sapphire 10 substrate, thereby improving the efficiency of the dewetting process. It had a great influence on the uniform formation.

In particular, the growth of the platinum nanostructure can be represented by a roughness parameter Rq and a surface area to volume ratio (SAR) obtained by statistically treating surface roughness (RMS), where Rq represents an average surface height. , SAR represents the 3D surface area of the platinum nanostructure.

Rq can be expressed as in Equation 1 below.

Where Zn is the profile height at each pixel.

SAR is given by Equation 2 below.

Where Ag and As are the geometric area (2D area) and the surface area (3D area), respectively.

As shown in graphs (j) and (k) of FIG. 3, Rq and SAR continuously increased with the increase in temperature.

에서 Rq 값은 약 5nm에서 10nm로 증가하였고, SAR 값은 4%에서 11%로 큰 증가를 보였다.Referring to graphs (j) and (k) of FIG. 3, 700

At, the Rq value increased from about 5 nm to 10 nm, and the SAR value showed a large increase from 4% to 11%.

In addition, as shown in graph (l) of FIG. 3, the results of atomic characterization through an energy dispersive X-ray spectrometer (EDS, hereinafter referred to as EDS) are three atoms (O Kα, Al Kα and Pt Mα1). It shows that the peak for) is commonly detected.

Here, the peaks of O Kα and Al Kα correspond to the atoms constituting the sapphire 10 as the substrate, and the peak of Pt Mα1 corresponds to the atoms constituting the platinum nanoparticles.

On the other hand, the indium (In) atom is desorption, a phenomenon in which ions, atoms, and molecules are separated from the adsorbent and transferred to the solution. In this embodiment, the indium (In) atom is related to No EDS peak was obtained.

However, as the temperature increases, a very small amount of residual indium (In) in the nanoparticles (NP) gradually desorbed from the nanoparticles by dewetting may be detected.

On the other hand, it can be seen that the amount of platinum (Pt) is kept constant throughout the temperature range ranging from 550°C to 900°C as shown in the summary chart shown in graph (l-1) of FIG. 3.

This indicates that there is no relationship between the shape of each platinum (Pt) nanoparticle formed on the surface of the sapphire 10 and the total amount of platinum (Pt).

Meanwhile, FIG. 5 shows the optical properties of platinum nanoparticles (Pt NP) produced and produced in a double layer of indium (In) 5 nm and platinum (Pt) 5 nm at 550°C to 900°C.

Graphs (a) to (c) of FIG. 5 represent reflectance, transmittance, and extinction spectra, respectively.

In this example, reflectance and transmittance spectra were experimentally measured in normal reflection and transmission modes, and extinction spectra were extracted in the relationship of extinction spectrum (%) = 100%-(reflectance + transmittance)%.

In general, platinum nanoparticles (Pt NP) are very sensitive to morphological changes, so the optical spectrum of platinum nanoparticles (Pt NP) shows the formation of various resonance peaks and reduced dips in a specific wavelength range. Is observed, and a change in intensity is observed.

Specifically, referring to the graph (a) of FIG. 5, when the diameter of the platinum nanoparticles (Pt NP) is 100 nm and the height is less than 30 nm, the reflectance of the optical spectrum of the platinum nanoparticles (Pt NP) is in the visible and near-infrared regions. The slope is lowered at.

In the graph (a) of FIG. 5, a peak at which the reflectance of the platinum nanoparticles (Pt NP) increases rapidly or a dip that decreases rapidly is not shown, but the size of the platinum nanoparticles (Pt NP) is formed. As a basis, the optical spectrum generated in the local surface plasmon resonance (LSPR) mode of dipolar and quadrupolar platinum nanoparticles (Pt NP) is observed in the ultraviolet (UV) and visible (VIS) regions. can do.

On the other hand, in the graph (a) of FIG. 5, because of the remarkable backscattering phenomenon caused by dipolar NPs at ultraviolet (UV) and visible (VIS) wavelengths, absorption of light is reduced, and the reflectance curve is reduced to ultraviolet rays ( UV) shows a shoulder pattern in the visible light (VIS) region.

The graph (b) of FIG. 5 shows transmittance, shows a dip at ~320nm, which is an ultraviolet (UV) region, and clearly shows a wide dip at ~460nm, which is a visible light (VIS) region. .

As shown in graph (b) of FIG. 5, the formation of a wavelength dependent dip in the transmittance graph is related to the excitation of various local surface plasmon resonances (LSPRs).

In particular, the dip of local surface plasmon resonance (LSPR) in the visible light (VIS) region is caused by the dipolar resonance mode, while the dip of local surface plasmon resonance (LSPR) in the ultraviolet (UV) region. (dip) may be generated by a quadrupolar resonance mode of platinum nanoparticles (Pt NPs).

As shown in the graphs (a) and (b) of FIG. 5, the reflectance of the platinum nanoparticles decreases at a wavelength longer than 750 nm, but the transmittance of the platinum nanoparticles rapidly increases in the near-infrared (NIR) region, resulting in a distinct shoulder pattern. It shows the graph of (shoulder pattern).

Since the wavelength region longer than 750 nm is a wavelength band that is far from excitation of local surface plasmon resonance (LSPR), high transmittance or low reflectance may not be measured in the near infrared (NIR) region due to the enhanced absorption and/or scattering phenomenon. I can.

On the other hand, since the refractive index mismatch between the air layer and the sapphire 10 is reduced by the layer of platinum nanoparticles (Pt NPs), the surface reflectance of the platinum nanoparticles decreases and the transmittance increases.

As shown in the graph (d) of FIG. 5, as the temperature increases, the average surface coverage of the platinum nanoparticles (Pt NP) decreases, and the average reflectance (R) of the platinum nanoparticles corresponding to the average size gradually decreases. Indicate that you are doing.

On the other hand, as the temperature increases, platinum nanoparticles are formed, and as the platinum thin film layer decreases on the sapphire substrate and the pure sapphire portion increases, the average transmittance (T) increases.

The dip of the local surface plasmon resonance (LSPR) clearly expressed in the reflectance and/or transmittance graph means the absorption or scattering of photons, which is the local surface in the extinction rate graph shown in graph (c) of FIG. It also appears as a peak of plasmon resonance (LSPR).

Referring to the graph (c) of FIG. 5, the position at which the peak of the local surface plasmon resonance for dipolar and quadrupolar platinum nanoparticles is formed is the graph of FIG. 5, which is a transmittance graph ( In b), a dip of local surface plasmon resonance is formed at a position corresponding to or similar to the formed position.

In order to specifically analyze the peak or dip trend of the local surface plasmon resonance that occurs with the evolution of platinum nanoparticles (Pt NPs), the detected optical spectrum is normalized and enlarged in the graph of FIG. 5 ( a-1) and graph (c-2).

Specifically, the standardized reflectance graph of graph (a-1) of FIG. 5 is characterized in that a graph of a shoulder pattern appears in the ultraviolet to visible light (UV-VIS) region, which occurs together with the back scattering effect. This is due to the excitation of the distinct surface plasmon resonance of the bipolar platinum nanoparticles and the small size of platinum nanoparticles (Pt NP).

From the standardized transmittance graph of graph (b-1) of FIG. 5, it can be seen that the dip of the local surface plasmon resonance gradually decreases in the ultraviolet to visible (UV-VIS) region as the temperature increases.

This is because light absorption gradually increases due to the formation of platinum nanoparticles (Pt NP) having a large and clear shape.

In addition, referring to the standardized extinction rate graph of graph (c-1) of FIG. 5, the size of the platinum nanoparticles (Pt NP) increases and the shape becomes clear, and the surface of the dipolar platinum nanoparticles Plasmon resonance shows a major peak in the visible light (VIS) region, and the surface plasmon resonance for quadrupolar platinum nanoparticles shows a relatively minor peak in the ultraviolet (UV) range. .

Furthermore, it can be seen that as the size of the platinum nanoparticles (Pt NP) increases and the shape becomes clear, the stiffness of the platinum nanoparticles gradually increases with the increase of temperature.

Meanwhile, referring to graph (c-1) of FIG. 5, platinum nanoparticles in a low temperature state have a small and irregular shape.

In this way, since platinum nanoparticles (Pt NP) of an overall irregular and small shape are widely distributed on the sapphire 10 substrate, the peak of local surface plasmon resonance (LSPR) is wider at low temperature than at high temperature. appear.

Therefore, as the temperature increases, the platinum nanoparticles (Pt NP) have a more uniform hemispherical shape, and as shown in graphs (b-2) and (c-2) of FIG. 5, local surface plasmon resonance (LSPR) ), the bandwidth is narrowed.

The optical spectrum detected by applying local surface plasmon resonance to platinum nanoparticles formed according to the method of forming platinum nanoparticles (Pt NP) by depositing only a platinum thin film layer on a conventional sapphire 10 substrate, and As a result of comparing the optical spectra detected by applying local surface plasmon resonance to platinum nanoparticles formed according to the method, the method according to the present invention is more uniform and clearly separated platinum nanoparticles (Pt NP) compared to the conventional method. It was confirmed that can be formed.

In addition, it can be seen that the optical spectrum detected from the platinum nanoparticles formed according to the present invention has a distinct and strong local surface plasmon resonance (LSPR) wavelength band in the ultraviolet (UV) and visible (VIS) regions.

Moreover, when platinum nanoparticles are formed according to the present invention, the overall efficiency of the dewetting process is improved by the sacrificial indium (In) layer, and the local surface plasmon resonance ( LSPR) may change the wavelength band.

On the other hand, in the method of constructing platinum nanoparticles according to the second and third embodiments of the present invention, the indium (In) and platinum (Pt) thin film layers are configured to have different thicknesses, respectively, and the first embodiment of the present invention Likewise, a platinum (Pt) thin film layer is configured to be deposited on an indium (In) thin film layer.

Hereinafter, a method of constructing platinum nanoparticles according to a second embodiment of the present invention will be described with reference to FIGS. 6 to 8. In addition, the shape and characteristics of the platinum nanoparticles generated by the dewetting process according to the second embodiment and the method according to the second embodiment will be described in detail.

Meanwhile, in describing the method of constructing platinum nanoparticles according to the second exemplary embodiment of the present invention, a description of the same or overlapping configuration as the first exemplary embodiment of the present invention may be omitted.

6 is an AFM plan view, an AFM side view, a cross-sectional line-profile and graphs measured and analyzed for each temperature of the composition of platinum nanoparticles according to a second embodiment of the present invention, and FIG. 7 is a second embodiment of the present invention. Is a histogram of the size distribution of platinum nanoparticles, and FIG. 8 is a graph showing optical properties of the platinum nanoparticles according to the second embodiment of the present invention.

Referring to FIG. 6, in the method of constructing platinum nanoparticles according to the second embodiment of the present invention, an indium (In) layer is formed of 15 nm, a platinum (Pt) layer is formed of 5 nm, _{and'In 15 nm} /Pt _It is denoted as ' _5nm bilayer'.

In this embodiment (the second embodiment), when the thickness of the indium (In) layer is changed while maintaining the same thickness of the platinum (Pt) layer under the same growth conditions as the previous embodiment (the first embodiment), platinum nano It is prepared to show what changes occur in the evolution of particles and what effects are produced accordingly.

Referring to the side views (b-1) to (i-1) taken with an atomic force microscope (AFM) of FIG. 6, the size, density, distribution, and spatial image of platinum nanoparticles (Pt NP) generated according to the present embodiment It can be seen that the arrangement is more diverse than in the previous embodiment.

For example, referring to the AFM plan view (c) and AFM plan view (d) of FIG. 6, the platinum nanoparticles (Pt NP) obtained at 600°C or less are smaller than the platinum nanoparticles (Pt NP) obtained at more than 600°C. It has been shown that the platinum nanoparticles (Pt NP) obtained by exceeding 600°C have a decrease in areal density as the size increases.

Moreover, as the indium-platinum (In-Pt) double layer deposited according to the present embodiment undergoes a dewetting process, a transition phenomenon occurring at a specific annealing temperature is clearly distinguished and dynamic than in the previous embodiment.

This is because the phenomenon of global diffusion of metal atoms including indium (In) and platinum (Pt) atoms is promoted by the indium (In) layer having an increased thickness.

Meanwhile, in this embodiment, as the initial thickness of each of the indium (In) and platinum (Pt) thin film layers constituting the double layer is changed, the efficiency of the dewetting process is further improved compared to the previous embodiment.

That is, in this embodiment, compared to the previous embodiment, the thickness of the platinum (Pt) layer is the same, but the thickness of the indium (In) layer and its component ratio are increased three times compared to the previous embodiment, so that the thickened indium ( The dewetting process can be finished more quickly than in the previous embodiment by the In) layer.

The method of forming platinum nanoparticles according to the present embodiment increases the interdiffusion of indium (In) atoms by increasing the thickness of the indium (In) layer compared to the previous embodiment, and during the dewetting process, indium-platinum In the alloy composed of (In-Pt) double layers, the overall diffusion of both indium (In) and platinum (Pt) atoms was improved, greatly increasing the efficiency of the overall dewetting process.

In this embodiment, when a void (void) is nucleated during the dewetting process, the accumulation of metal atoms diffused by the thickened indium (In) layer proceeds rapidly, and the sublimation of the indium (In) atom is also Since it proceeds quickly, the dewetting process according to the present exemplary embodiment proceeds very quickly compared to the previous exemplary embodiment.

As described above, in the method of constructing the platinum nanoparticles according to the present embodiment, due to the rapidly proceeding dewetting process, well-defined platinum nanoparticles (Pt NP) may be formed even at a much lower temperature than in the previous embodiment.

In more detail, as can be seen in the AFM top-views (b) to (d) of FIG. 6, the small platinum nanoparticles and voids are large as the temperature increases from 550°C to 700°C. It rapidly develops into compact platinum nanoparticles.

In particular, referring to the AFM top-views (b) of FIG. 6, small platinum nanoparticles at 550° C. are in a high-density state, and indium-platinum (In-Pt) in an alloy state composed of a double layer. ) And platinum (Pt) atoms are mutually diffusible.

In addition, as the temperature increases, indium (In) atoms are sublimated, and nuclei of platinum nanoparticles are immediately formed and/or generated.

In this embodiment, the small platinum nanoparticles grow by adhering to adjacent platinum nanoparticles, and form platinum nanoparticles (Pt NPs) having an elongated-dome shape.

The size of these dome-shaped platinum nanoparticles gradually increases as the temperature increases.

Meanwhile, as the size of the dome-shaped platinum nanoparticles increases, the density decreases.

In the cross-section-line profile (b-1) to the cross-section-line profile (d-1) of FIG. 6, the shape of the platinum nanoparticles (Pt NP) formed according to the present embodiment and the cross-section-line profile of the platinum nanoparticles Is shown.

Referring to the cross-sectional-line profile (b-1) to the cross-sectional-line profile (d-1) of FIG. 6, the height of the platinum nanoparticles (Pt NPs) increases from ~5 nm to 20 nm as the temperature increases, and the diameter increases. It can be seen that the increase was increased from ~50 nm to 200 nm.

Compared with the previous embodiment, the average height of the platinum nanoparticles according to the present embodiment was formed to be almost the same, but the side diameter of the platinum nanoparticles according to the present embodiment increased about twice as compared to the previous example, and the previous example Compared to the platinum nanoparticles show a more superior lateral growth.

As a result, as shown in the AFM plan view (f) to the AFM plan view (i) of FIG. 6, as the temperature increases from 750 to 900° C., the irregularly arranged large platinum nanoparticles gradually become hemispherical platinum nanoparticles spaced widely apart. Transformed.

In addition, while the diameter of the irregularly arranged large platinum nanoparticles gradually decreases, the shape of the platinum nanoparticles (Pt NPs) evolved into a semi-spherical configuration, and the vertical height of the platinum nanoparticles (Pt NPs). Becomes higher.

That is, as can be seen from the cross-sectional-line profile (b-1) to the cross-sectional-line profile (d-1) shown in FIG. 6, the average height of the platinum nanoparticles increased from -30 nm to 45 nm as the temperature increased, Rather, the diameter decreased slightly from ~150nm to 120nm.

This is, in order for the platinum nanoparticles (Pt NPs) to obtain thermal stability, the vertical height of the platinum nanoparticles is superior to that of the previous embodiment, and vertically grown. The surface and interface energy of the platinum nanoparticles (Pt NPs) having an increased vertical height are minimized.

In addition, compared to the previous example, the platinum nanoparticles formed according to this example had a reduced overall density, but their size increased. Referring to FIG. 7, a histogram of the size distribution of platinum nanoparticles (Pt NPs) according to the present embodiment can be viewed, and compared with the previous embodiment, it can be seen how much the size is larger.

Meanwhile, as shown in graph (j) of FIG. 6, it can be seen that as the temperature increases, the Rq value increases from 3 nm to 10 nm, and the SAR value increases steeply from 1% to 12%, respectively.

Atoms present in the platinum nanoparticles formed according to this embodiment can be confirmed by the EDS spectrum result shown in graph (a) of FIG. 8.

Referring to the graph (a) of FIG. 8, this embodiment uses an indium (In) layer with a thickness of 15 nm that is three times thicker than the previous embodiment, and a more dynamic dewetting process is performed at a high temperature compared to the previous embodiment. Can be seen.

As can be seen from the graph (b) of FIG. 8, In Lα1 representing an indium (In) atom was observed between 550°C and 800°C, but at 800°C or higher, In Lα1 completely disappears, and In Lα1 cannot be observed.

This means that a small amount of indium (In) can be present in the platinum nanoparticles (NP) up to 800°C.

As can be seen from the Pt Mα1 shown in the graph (b) of FIG. 8, the amount of platinum (Pt) deposited can be confirmed that the content is kept constant in almost all temperature bands, which is similar to the EDS spectrum result of the previous example. Do.

On the other hand, when referring to the reflectance, transmittance, and extinction coefficient shown in graphs (c) to (e) of FIG. 8, respectively, the platinum nanoparticles according to the present embodiment have various optical properties compared to the previous embodiment. You can see that there is.

In this embodiment, the diameter of the platinum nanoparticles (Pt NP) is at least 170nm or more, which is larger than the average diameter of the platinum nanoparticles according to the previous embodiment, and since each platinum nanoparticles are widely dispersed and separated from each other on the substrate, according to the previous embodiment. In contrast, the optical properties of the platinum nanoparticles according to the present embodiment appear variously.

Compared to the previous embodiment, the evolution of platinum nanoparticles (Pt NP) according to this embodiment has been more dynamically changed as the number of indium (In) components deposited on the substrate is increased, and indium annealed from 550°C to 900°C- Looking at the optical properties of the platinum nanoparticles produced by using the platinum (In-Pt) double layer, it can be seen that the optical properties changed more clearly compared to the previous embodiment.

Looking more specifically, graph (c) of FIG. 8 is a graph showing reflectance, showing a graph of a shoulder pattern in the ultraviolet (UV) region of ~320 nm, and visible light (VIS) between 450 nm and 600 nm. ) Area also shows a graph of the shoulder pattern.

Local surface plasmon resonance (LSPR) for platinum nanoparticles (Pt NP) according to the present invention can be greatly affected by backscattering, which is represented by a graph of a shoulder pattern in the reflectance graph, and this embodiment In, a graph of a shoulder pattern in the ultraviolet (UV) and visible light (VIS) regions is shown.

Referring to the graph (c) of FIG. 8, in the case of platinum nanoparticles formed on a sapphire 10 substrate using an indium-platinum (In-Pt) double layer annealed at 550°C, which is a temperature lower than 900°C, platinum As the shape and distribution uniformity of nanoparticles (Pt NP) improves, the graph of the shoulder pattern, which appeared relatively narrow in the visible light (VIS) region, gradually increased in temperature, resulting in a much wider shoulder pattern. It is shown as a graph of.

Referring to the graph (d) of FIG. 8, in the graph showing the transmittance of platinum nanoparticles, dips of local surface plasmon resonance for dipolar and quadrupolar platinum nanoparticles are respectively converted to ultraviolet ( UV) and visible light (VIS) are clearly visible.

On the other hand, looking at the transmittance graph (d) of FIG. 8, regardless of how the surface shape of the platinum nanoparticles (Pt NP) is formed, the peak of the local surface plasmon resonance for the quadrupolar platinum nanoparticles (quadrupolar Pt NP) ( peak) and dip trends are shown to be the same as in the previous embodiment.

However, looking at the transmittance graph (d) of FIG. 8, it can be seen that the dip of the local surface plasmon resonance for the dipolar platinum nanoparticles (dipolar Pt NP) is significantly changed compared to the previous example.

That is, referring to the graphs (c) to (e) of FIG. 8, the dip of the local surface plasmon resonance for the dipolar platinum nanoparticles (dipolar Pt NP) is compared with the previous embodiment, near infrared (NIR) Transition to the realm.

내지 600

의 비교적 낮은 온도에서 어닐링된 인듐-백금(In-Pt) 이중 층을 이용하여 사파이어(10) 기판 상에 형성된 백금 나노 입자(Pt NP)는 사파이어(10) 기판상의 넓은 영역에 분포되어 있으므로, 쌍극성 백금 나노 입자에 대한 국소 표면 플라즈몬 공명의 피크(peak)는 넓게 나타나다가, 온도가 고온으로 증가하면서 백금 나노 입자(Pt NP)의 크기가 커지고 형상의 균일성이 개선되면서 피크의 폭이 크게 좁아지는 것으로 나타난다.Also, 550

To 600

The platinum nanoparticles (Pt NP) formed on the sapphire 10 substrate by using an indium-platinum (In-Pt) double layer annealed at a relatively low temperature of are distributed over a large area on the sapphire 10 substrate, The peak of the local surface plasmon resonance for the polar platinum nanoparticles appears wide, and as the temperature increases to a high temperature, the size of the platinum nanoparticles (Pt NP) increases and the shape uniformity improves, resulting in a significantly narrower peak. Appears to lose.

In graphs (c-1) to (e-2) of FIG. 8, optical properties of platinum nanoparticles (Pt NP) formed according to the present embodiment are represented by standardized reflectance, transmittance, and extinction coefficient.

Graphs (c-1) to (e-2) of FIG. 8 show trends in how local surface plasmon resonance (LSPR) appears as the platinum nanoparticles (Pt NP) of the present embodiment evolve.

As shown in graph (c-1) of FIG. 8, in the graph representing the standardized reflectance, the graph of the shoulder pattern is shown in the ultraviolet (UV) and visible (VIS) regions.

In addition, as the temperature gradually increases, the graph of the shoulder pattern appearing in the visible light (VIS) region is composed of a short wavelength.

This is because as the temperature increases, the size of the platinum nanoparticles (Pt NP) increases and the uniformity of the shape is improved.

On the other hand, as the temperature increases, the graph (d-1) of FIG. 8 shows that the dip of local surface plasmon resonance (LSPR) extends deeper and longer in the ultraviolet (UV) and visible (VIS) regions. .

In particular, as shown in the graph (e) of FIG. 8, in the graph of the extinction rate of the platinum nanoparticles according to the present embodiment, the peak of the local surface plasmon resonance of the quadratic and bipolar platinum nanoparticles is They appear in the ultraviolet (UV) and visible (VIS) regions, respectively.

In addition, the average reflectance (R) and transmittance (T) of the platinum nanoparticles measured at a specific annealing temperature are shown in the graph (f) of FIG. 8.

Referring to the graph (f) of FIG. 8, as the temperature increases and the surface coverage of the platinum nanoparticles (Pt NP) gradually decreases, the transmittance of the platinum nanoparticles decreases and the reflectance gradually increases. .

Meanwhile, the fact that the platinum nanoparticles according to the present embodiment exhibit a low extinction rate in the near infrared (NIR) region is due to the high transmittance of the platinum nanoparticles and relatively low absorption of local surface plasmon resonance.

This is because the light absorption intensity of platinum nanoparticles (Pt NP) formed to have a larger and distinct shape with a wide distance from each other is gradually improved.

As a result, as shown in graph (e-1) of FIG. 8, in a graph showing the extinction rate of platinum nanoparticles (Pt NP), it was found that the peak intensity of local surface plasmon resonance (LSPR) was improved. I can.

Referring to the graph (e-1) of FIG. 8, in the graph showing the standardized extinction rate, the peak of the local surface plasmon resonance of the bipolar platinum nanoparticles is higher than the peak of the local surface plasmon resonance of the quadratic platinum nanoparticles. It appears that the nanoparticles (Pt NP) react more sensitively to changes in shape.

As shown in graphs (d-2) and (e-2) of FIG. 8, the size and shape uniformity of platinum nanoparticles (Pt NP) are improved with an increase in temperature, while localization for platinum nanoparticles The wavelength band of surface plasmon resonance (LSPR) has been substantially narrowed.

Compared with the previous example, in this example, the size and shape of the platinum nanoparticles (Pt NP) were further improved, so the distribution and diffusivity of the platinum nanoparticles (Pt NP) were improved. There was an effect that the wavelength band of plasmon resonance (LSPR) was narrowed compared to the previous embodiment.

In addition, the method of constructing the platinum nanoparticles according to the second embodiment improves the overall dewetting efficiency by changing only the thickness of the indium (In) layer while maintaining a constant thickness of the platinum (Pt) layer. It can change the optical properties of the particles.

Moreover, when the dewetting process is performed on the indium-platinum (In-Pt) double layer according to the present embodiment, dewetting (dewetting, dewetting or non-wetting) is performed on a substrate on which only a conventional platinum (Pt) thin film layer is deposited. In contrast to the case of performing the process, the efficiency of the overall dewetting process is remarkably improved by the introduction of the indium (In) component, and platinum nanoparticles (Pt NP) with improved uniformity can be produced and manufactured.

Hereinafter, a method of constructing platinum nanoparticles according to a third embodiment of the present invention will be described with reference to FIGS. 9 to 10. In addition, the shape and characteristics of the platinum nanoparticles generated by the dewetting process according to the third embodiment of the present invention and the method according to the third embodiment will be described in detail.

Meanwhile, in describing the method of constructing platinum nanoparticles according to the third embodiment of the present invention, a description of the same or overlapping configuration as the first embodiment of the present invention may be omitted.

9 is an AFM plan view, an AFM side view, a cross-sectional line-profile and graphs measured and analyzed for each temperature of the composition of platinum nanoparticles according to a third embodiment of the present invention, and FIG. 10 is a third embodiment of the present invention. These are graphs showing the optical properties of platinum nanoparticles.

In the method of constructing platinum nanoparticles according to the third embodiment of the present invention, a 15 nm platinum (Pt) layer is deposited on a 5 nm indium (In) layer, and is expressed as'In _{5 nm} /Pt _{15 nm} bilayer'.

Referring to FIG. 9, the method of constructing platinum nanoparticles according to the third embodiment of the present invention is similar to the first embodiment of the present invention, while maintaining the thickness of the indium (In) layer at 5 nm, the platinum (Pt) layer The double layer is formed with a thickness of 15 nm, which is three times thicker than the existing embodiment (first embodiment).

In the third embodiment of the present invention, the process and method of evolving into a platinum nano cluster (Pt nano cluster) by thickening only the platinum (Pt) layer in this manner are shown.

In this embodiment (third embodiment), only the thickness of the platinum (Pt) layer is maintained while maintaining the same thickness of the indium (In) layer as in the previous embodiment under the same growth conditions as the previous embodiment (the first embodiment). By changing, it was prepared to see how the increase in the platinum (Pt) component affects the evolution of platinum nanoparticles or platinum nanoclusters.

The process and method of generating and evolving platinum nanoclusters using the double layer of this embodiment in which only the thickness of the platinum (Pt) thin film layer is changed are significantly different compared to those of the previous embodiment.

AFM top-views (a) to (f) of FIG. 9 show various stages of growth of platinum (Pt) nanoclusters.

In this embodiment, i) generation and growth of void nuclei and ii) formation of platinum nanoclusters irregularly connected to each other can be observed, and finally, iii) platinum nanoclusters are decomposed and randomly dispersed and isolated. The process of forming platinum nanoparticles is also possible.

In this embodiment, the total thickness of the indium-platinum (In-Pt) double layer is the same as in the previous embodiments, but since the content of the platinum (Pt) component is significantly increased, the overall efficiency for the dewetting process is changed.

In this embodiment, the thickness of the indium (In) layer has a thickness of 5 nm as in the previous embodiment, while the thickness of the platinum (Pt) layer increases three times from 5 nm to 15 nm. Therefore, in this embodiment, unlike the previous embodiments in which the dewetting process and efficiency were dynamic, the stability of the dewetting process and efficiency was improved.

On the other hand, as the thickness of the platinum (Pt) layer increases, the degree to which each of the indium (In) and platinum (Pt) atoms are mutually diffuse, the degree of alloying of indium-platinum (In-Pt), and the degree of diffusion of all metal atoms are previously It was lowered compared to the examples.

Accordingly, the present embodiment is more inferior in dewetting efficiency at the same temperature as the previous embodiments.

In more detail, as shown in the AFM plan view (a) of FIG. 9, the surface of the sapphire 10 substrate becomes rough as platinum nanoparticles and voids having a small size at 550° C. are formed.

Although the height of the small platinum nanoparticles is less than 3 nm, as shown in the graph (a-1) of FIG. 9, some platinum nanoparticles exhibiting a random anisotropic diffusion phenomenon unexpectedly grew to 8 nm in height.

Meanwhile, as the temperature increases, not only the sublimation rate of indium (In) atoms but also the surface diffusion rate of all metal atoms including platinum (Pt) atoms increases.

As a result, as shown in the AFM plan view (b) of FIG. 9 and the AFM side view (b-1) of FIG. 9, surface diffusion of platinum (Pt) atoms and sublimation of indium (In) atoms increase at 650° C. The (void) grows, and the dewetting process is further advanced by adhesion between adjacent voids.

In addition, as shown in the AFM plan view (d) of FIG. 9, the voids were almost merged with each other at 750° C. to expose a lot of pure sapphire 10 regions on the sapphire 10 substrate, and had an average height of -50 nm. Platinum nanoclusters in the form of irregularly connected networks are formed.

In this embodiment as well, the process of growing voids is induced by minimizing the interface energy between the metal thin film layer and the sapphire 10.

로 증가하면, 도 9의 AFM 평면도 (f)에 나타난 바와 같이, 표면 에너지 이방성과 백금 나노 클러스터 주변부의 레일리형(Rayleigh-like) 불안정성으로 인하여, 서로 연결된 백금 나노 클러스터가 불규칙하게 분산 격리된 백금 나노 입자로 분열된다.Meanwhile, the temperature is 900

As shown in the AFM plan view (f) of FIG. 9, due to the surface energy anisotropy and Rayleigh-like instability around the platinum nanoclusters, platinum nanoclusters connected to each other are irregularly dispersed and isolated platinum nanoparticles. Breaks into particles.

As described above, in the case of the irregularly dispersed and isolated platinum nanoparticles, the spacing between the platinum nanoparticles increases and at the same time has a compact size and shape, so that surface energy and interfacial energy are naturally reduced.

The AFM side view (a-1) to the AFM side view (f-1) of FIG. 9 specifically represent the evolution of the surface morphology of the platinum nanoparticles at a specific temperature.

A cross-sectional line profile for each of the AFM side view (a-1) to the AFM side view (f-1) of FIG. 9 shows the size and shape of the platinum nanoclusters.

First, referring to the AFM side view (a-1) to the AFM side view (f-1) of FIG. 9, the platinum nanoparticles formed according to this embodiment have a vertical height and a side length of 550° C., respectively, compared to the previous embodiment. It increased about 5 times at and 10 times at 900°C.

In addition, referring to graphs (g) and (h) of FIG. 9, Rq values and SAR values gradually increased with the evolution of platinum nanoparticles (Pt NPs).

However, referring to the graph (h) of FIG. 9, due to the rapid decrease in the average surface coverage of the platinum nanoclusters, the SAR value shows a tendency to slightly decrease at 750°C or higher.

In addition, referring to the graph (i) of FIG. 9, after the dewetting process, EDS spectrum analysis was performed on the sapphire 10 substrate and the platinum nanocluster, confirming that only the platinum (Pt) atom Pt Mα1 and the substrate atom were detected. I can. That is, it can be seen that all of the indium (In) atoms are sublimated through the dewetting process.

In this embodiment, the deposition amount of indium (In) was three times lower than that of the previous embodiment (the second embodiment), and the indium (In) atom was not detected at all as confirmed by the graph (i) EDS spectrum result of FIG. Therefore, it can be seen that the sapphire 10 is completely sublimated from the substrate.

10 is a graph showing optical properties of platinum nanoclusters according to the present embodiment in terms of reflectance, transmittance, and extinction rate.

Referring to the graph of FIG. 10, it can be seen that the optical properties of the platinum nanocluster according to the present embodiment are in contrast to the previous embodiment (the second embodiment) and are very diverse.

This is, in the previous embodiment (second embodiment), small, isolated and spherical platinum nanoparticles (Pt NP) were formed on the substrate, but in this embodiment (third embodiment), platinum nanoparticles are connected to each other to form a platinum nanocluster. This is because it constitutes.

For example, referring to graph (a) of FIG. 10, in the reflectance graph of the platinum nanocluster according to the present embodiment, a dip of the local surface plasmon resonance of the platinum nanocluster is a visible light (VIS) region of ~495 nm It is clearly seen in the ultraviolet (UV) region of and ~320nm.

This is, when comparing the previous example (the second example) and the present example (third example) composed of platinum nanoparticles that are regularly uniformly dispersed and isolated, a grain-shaped void that can be observed in this example. And it shows that the optical properties of the platinum nanoclusters that are largely formed by being connected to each other are different from the optical properties of the previous embodiment.

In this embodiment, excitation of local surface plasmons of various multipoles platinum nanoclusters including bipolar, quadrupole, and higher order mode (HR) is generated by the interaction of photons. As compared to the previous embodiment, the difference in optical properties occurs.

On the other hand, the platinum nanoclusters formed according to the present embodiment maintain an average width of 500 nm, and platinum nanoparticles are connected to each other while the height is 30 nm.

In order to induce a single local surface plasmon resonance phenomenon, various multipoles corresponding to a dip of local surface plasmon resonance in the visible light (VIS) region of the reflectance graph may overlap each other.

On the other hand, a dip of local surface plasmon resonance in the ultraviolet (UV) region may contribute to a higher order resonance mode (HR) as well as a transition between bands of electrons.

In this embodiment, the dip of the local surface plasmon resonance shown in the reflectance graph is correlated with the phenomenon that the platinum nanoparticles exhibit improved photon absorption and/or the forward scattering phenomenon due to the multipoles resonance (MR). have.

In addition, in this embodiment, since the size of the platinum nanoparticles (Pt NP) is larger than in the previous embodiment, the Multipoles Resonance (MR) mode exhibits a more remarkable effect than other modes.

The transmittance shown in the graph (b) of FIG. 10 is a characteristic distinguishing from the previous embodiment, and shows a graph of a shoulder pattern in the ultraviolet (UV) region ~320nm and the visible light (VIS) region ~485nm.

In this embodiment, the reason why such a shoulder pattern appears in the transmittance graph is that forward scattering of light occurs due to the multipoles resonance (MR) mode of the large platinum nanocluster. .

Referring to the graph (b) of FIG. 10, when platinum nanoparticles (Pt NP) are irregularly dispersed and isolated at 900°C, the dip of the local surface plasmon resonance in the transmittance graph is in the visible light (VIS) region. Appears, and it can be seen that the dip of the local surface plasmon resonance is easily shifted compared to the previous example.

Meanwhile, it can be seen that the platinum nanoparticles (Pt NP) formed by irregular dispersion and isolation according to the present embodiment also improve light absorption in the visible light (VIS) region, but rather reduce forward scattering, as in the previous embodiment.

As shown in each of the graphs (a-1) and (b-1) of FIG. 10, this embodiment is similar to the previous embodiment, while the surface coverage of the platinum nanoparticles (Pt NP) decreases and the average The reflectance (R) decreases and the transmittance (T) increases.

Referring to the graph (c) of FIG. 10, in the extinction rate graph, the local surface plasmon resonance peaks for the platinum nanoclusters in the multiple (MR) and high-order resonance (HR) modes are narrowed in the visible light (VIS) region, respectively. Appeared, and the peak appeared wide in the ultraviolet (UV) region.

On the other hand, in this embodiment, since the platinum nanoclusters are widely distributed and connected to each other on the sapphire 10 substrate, the peak of local surface plasmon resonance (LSPR) is generally more than that of the previous embodiment. Appears widely.

Referring to the graph (a-2) of FIG. 10, in the graph showing the standardized reflectance, it can be seen that the dip intensity of the local surface plasmon resonance for the multi-polar platinum nanocluster gradually increases as the temperature increases. have.

This is because backscattering increases as platinum nanoparticles (Pt NP) evolve with increasing temperature.

In addition, referring to the graph (b-2) of FIG. 10, which is a graph showing the standardized transmittance, widely distributed and connected platinum nanoclusters are gradually isolated into platinum nanoparticles (Pt NP), thereby reducing forward scattering and reducing light absorption. You can see it increases.

Referring to the graph (c-1) of FIG. 10, platinum nanoclusters that are widely distributed on the sapphire 10 substrate and connected to each other with a high coverage rate undergo a dewetting process, and gradually show local surface plasmon resonance (LSPR). It can be seen that the overall effect is improved.

As compared with the previous example, the platinum nanoparticles formed according to the method of the present embodiment show improved light absorption and scattering in the visible light (VIS) region.

Referring to graph (c-2) of FIG. 10, the peak of local surface plasmon resonance (LSPR) appears narrower by the separated platinum nanoparticles (Pt NPs).

This means that the formation of separated platinum nanoparticles (Pt NPs) also affects the peak band-width of local surface plasmon resonance (LSPR).

That is, in order to form platinum nanoparticles on the sapphire 10 substrate, the present invention polishes both sides of the C-side sapphire 10 substrate offset by ±0.1° of 99.999% purity to a thickness of ~430 μm, and the substrate Dicing and degassing in a pulsed laser deposition chamber (PLD), depositing the degassed substrate as a double layer of indium-platinum in a sputter chamber, and then depositing sapphire with a double layer of indium-platinum (10) In order to anneal the substrate, it is repositioned in a pulsed laser deposition chamber to anneal, and the annealed indium-platinum deposited substrate is dewetted.

When the sapphire 10 substrate is diced and degassed, the inside of the pulsed laser deposition chamber is set to conditions of 1×10 ^-4 Torr and 600°C, and the substrate is held inside the pulsed laser deposition chamber for 30 minutes under these conditions. .

Further, when the sapphire 10 substrate is deposited, the interior of the sputter chamber is set to 1×10 ⁻¹ Torr.

And when the sapphire substrate is deposited, indium (In) and platinum (Pt) are sequentially deposited on the sapphire 10 substrate at a deposition rate of 0.05 nm/s at 5 mA ionization current.

At this time, by using a computer program, it is possible to adjust the deposition time of indium (In) and platinum (Pt) in minutes, respectively.

In addition, thin film thicknesses of indium (In) and platinum (Pt) may be respectively adjusted by controlling the deposition time of indium (In) and the deposition time of platinum (Pt).

The sapphire 10 substrate on which the double layer of indium-platinum is deposited is rearranged in the pulsed laser deposition chamber and annealed. When the sapphire 10 substrate is rearranged in the pulsed laser deposition chamber, the pressure inside the pulsed laser deposition chamber is It is lowered to less than 1×10 ^-4 Torr.

After the sapphire (10) substrate on which the double layer of indium-platinum is deposited is annealed, the temperature inside the pulsed laser deposition chamber is increased at a rate of 4℃ sec ^{-1, and} the temperature inside the pulsed laser deposition chamber is 550℃. The dewetting process is set to reach a specific target temperature between to 900°C.

During the dewetting process, when the temperature inside the pulsed laser deposition chamber reaches a specific target temperature between 550°C and 900°C, the sapphire 10 substrate is maintained at that target temperature for 450 seconds.

When the sapphire (10) substrate on which the double layer of indium-platinum is deposited finishes the dewetting process, the operation of the heating system is stopped so that the temperature inside the pulsed laser deposition chamber decreases, and the same vacuum state as during the dewetting process is maintained. It allows the interior of the pulsed laser deposition chamber to be naturally cooled over time by the ambient atmosphere.

The present invention provides platinum nanoparticles having various shapes, sizes and shapes through a thermal dewetting (thermal dewetting) process for a platinum (Pt) layer continuously deposited on a sacrificial indium (In) layer. It is about a method of generating a platinum nano matrix consisting of (Pt NP).

Platinum nanoparticles (Pt NP) according to the present invention are based on excitation of dipole, quadrupole, and high-order resonance modes, and local surface plasmon resonance (LSPR) in the ultraviolet (UV) and visible (VIS) regions. ) Of the wavelength band (wavelength band) appears dynamically.

More specifically, the wavelength band of local surface plasmon resonance (LSPR) is adjusted to ~480nm and ~580nm by platinum nanoparticles (Pt NP) of various sizes having a uniform shape and interparticle spacing.

Meanwhile, the present invention uses sacrificial indium (In) to control the shape of nanoparticles (NP) formed on the substrate surface while platinum (Pt) having a diffusivity lower than indium (In) undergoes a dewetting process. do.

That is, the sacrificial indium (In) makes it possible to control the morphology of the platinum nanoparticles (Pt NP) on the substrate surface.

In addition, in the present invention, the sacrificial indium (In) layer causes mutual mixing of indium (In) and platinum (Pt) atoms, and improves the overall diffusivity and uniformity of the platinum nano matrix.

In addition, by adjusting the thickness of the indium (In) layer while maintaining a constant thickness of the platinum layer, the size, spacing, and density of the formed platinum nanoparticles (Pt NP) can be easily controlled.

In addition, the dewetting process according to the present embodiment is performed at a relatively low temperature compared to the dewetting process for a substrate on which only a platinum (Pt) thin film is deposited, and during the annealing process, the thickness of the thin film (film) , A platinum nano-structure (Pt Nano Matrix) composed of various types of platinum nano particles (Pt NP) may be generated by varying the annealing temperature and duration.

Various types of platinum nanoparticles (Pt NP) formed according to the present invention include platinum nanoclusters, elongated platinum nanoparticles, and hemispherical platinum nanoparticles.

In addition, in the method of forming platinum nanoparticles according to the present invention, the size of platinum nanoparticles (Pt NP) and the size of platinum nanoparticles (Pt NP) are changed by making all other growth conditions the same and changing only the thickness of the sacrificial indium (In) layer. NP) interval can be adjusted.

In addition, the various types of platinum nanoparticles formed according to the present invention may have various optical properties including reflectance, transmittance, and extinction coefficient depending on the size and composition of the platinum nanoparticles (Pt NP). Surface Plasmon Resonance (LSPR) effects can be derived.

In particular, the present invention can obtain platinum nanoparticles (Pt NP) having various sizes and intervals by performing a dewetting process on an indium-platinum (In-Pt) double layer using a sacrificial indium (In) layer. It is possible to improve the efficiency of the dewetting process.

Moreover, the present invention introduces a sacrificial indium (In) layer, and at the same time as the temperature increases, the indium (In) atoms are completely separated by sublimation, the shape uniformity is improved, and independent platinum nanoparticles (Pt NP) By promoting the development of the dewetting (dewetting) process had a significant effect on the efficiency.

This is because the indium (In) component promotes the mutual diffusion of indium (In) and platinum (Pt) atoms, and greatly improves the diffusivity of metal atoms as a whole by indium-platinum (In-Pt) alloying.

In addition, the method according to the present invention has shown that it is possible to form platinum nanoparticles (Pt NP) uniformly distributed with a distinct shape at a relatively low temperature compared to the conventional method.

In particular, the platinum nanoparticles (Pt NP) according to the present invention have a larger size and uniform shape than that of the conventional platinum nanoparticles (Pt NP), so that the local surface plasmon resonance (LSPR) bandwidth of the platinum nanoparticles is varied, and the absorption of light Is enhanced and exhibits dynamic local surface plasmon resonance (LSPR) properties in the ultraviolet (UV) and visible (VIS) regions.

Above all, the present invention provides various structures of platinum nanoparticles (Pt NP) by individually changing only the thickness of indium (In) and platinum (Pt) in an indium-platinum double layer while keeping all other growth conditions the same, It is possible to obtain the shape, size, and density, and based on this, high-temperature treatment of the platinum (Pt) thin film during the platinum nanoparticle manufacturing process can be performed more easily than before. In addition, the present invention enables the manufacture of various platinum nanostructures.

Finally, the present invention can be applied not only to the production of platinum nanoparticles (Pt NP), but also to the production of other metal nanostructures for plasmon mediated optical, electronic, and catalytic systems.

Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made without departing from the spirit of the present invention.

Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative and non-limiting in all respects. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

10: sapphire

Claims (14)

Dicing and degassing the substrate in a pulsed laser deposition chamber (PLD);
Depositing the degassed substrate as a double layer of indium-platinum in a sputter chamber;
Annealing the substrate on which the double layer of indium-platinum is deposited by rearranging the substrate on which the double layer of indium-platinum is deposited in the pulsed laser deposition chamber; And
Comprising the step of dewetting the substrate on which the double layer of indium-platinum is deposited in the pulsed laser deposition chamber, forming platinum nanoparticles through dewetting on the double layer of indium-platinum (In-Pt) in a solid state How to.
The method according to claim 1,
The dicing and degassing step,
Step A in which the pulsed laser deposition chamber is set to a condition of 1Х10 ^-4 Torr and 600°C, and the substrate is maintained in the pulsed laser deposition chamber for 30 minutes under such conditions, further comprising, in a solid state Method of constructing platinum nanoparticles through dewetting on an indium-platinum (In-Pt) double layer.
The method according to claim 1,
Before the dicing and degassing step,
A method of constructing platinum nanoparticles through dewetting on a solid state indium-platinum (In-Pt) double layer, further comprising the step of polishing the substrate to a thickness of ~430 μm.
The method according to claim 1,
The substrate is composed of ±0.1° offset C-plane sapphire, a solid state indium-platinum (In-Pt) method of forming platinum nanoparticles through dewetting on a double layer. The method according to claim 1,
The depositing step,
A method of constructing platinum nanoparticles through dewetting on a solid state indium-platinum (In-Pt) double layer, further comprising step B in which the inside of the sputter chamber is set to 1×10 ⁻¹ Torr.
The method according to claim 1,
The depositing step,
A step C of depositing each thin film in the order of indium (In) and platinum (Pt) on the degassed substrate at a deposition rate of 0.05 nm/s at 5 mA ionization current; And
A step D of controlling the deposition time of each of the indium (In) and platinum (Pt) in minutes; further comprising,
The D step,
Indium-Platinum (In-Pt) in a solid state, which controls the thickness of the indium (In) and platinum (Pt) thin films by controlling the deposition time of indium (In) and the deposition time of platinum (Pt), respectively Method of constructing platinum nanoparticles through dewetting on a double layer.
The method of claim 6,
The D step,
Solid state further comprising step D-1 of respectively controlling a time when indium (In) is deposited and a time when platinum (Pt) is deposited so that a 5 nm platinum (Pt) layer is deposited on a 5 nm indium (In) layer Method of constructing platinum nanoparticles through dewetting on the indium-platinum (In-Pt) double layer of the state.
The method of claim 6,
The D step,
Solid state further comprising step D-2 of respectively controlling a time when indium (In) is deposited and a time when platinum (Pt) is deposited so that a 5 nm platinum (Pt) layer is deposited on a 15 nm indium (In) layer Method of constructing platinum nanoparticles through dewetting on the indium-platinum (In-Pt) double layer of the state.
The method of claim 6,
The D step,
Solid state further comprising step D-3 of respectively controlling a time when indium (In) is deposited and a time when platinum (Pt) is deposited so that a 15 nm platinum (Pt) layer is deposited on a 5 nm indium (In) layer Method of constructing platinum nanoparticles through dewetting on the indium-platinum (In-Pt) double layer of the state.
The method according to claim 1,
The annealing step,
Constructing platinum nanoparticles through dewetting on the solid state indium-platinum (In-Pt) double layer, further comprising the step E of lowering the pressure inside the pulsed laser deposition chamber to 1×10 ⁻⁴ Torr or less How to.
The method according to claim 1,
The annealing step,
A step F of increasing the temperature inside the pulsed laser deposition chamber at a temperature increase rate of 4° C. sec ^-1 ; And
Platinum through dewetting on the solid state indium-platinum (In-Pt) double layer, further comprising a G-th step in which the temperature inside the pulsed laser deposition chamber reaches a specific target temperature between 550°C and 900°C How to construct nanoparticles.
The method of claim 11,
After the G step,
The method of constructing platinum nanoparticles through dewetting on a solid state indium-platinum (In-Pt) double layer, further comprising an H-th step in which the substrate is maintained in the pulsed laser deposition chamber for 450 seconds.
The method of claim 12,
In the annealing step, the annealing is controlled by a computer program, a method of forming platinum nanoparticles through dewetting on a solid state indium-platinum (In-Pt) double layer.
The method according to claim 1,
After the dewetting step,
Stopping the operation of the heating system to lower the temperature inside the pulsed laser deposition chamber,
Stopping the operation of the heating system,
The vacuum state inside the pulsed laser deposition chamber is maintained the same as the vacuum state inside the pulsed laser deposition chamber in the dewetting step, and the inside of the pulsed laser deposition chamber is naturally cooled with the passage of time by the atmosphere to A method of constructing platinum nanoparticles through dewetting on a solid state of indium-platinum (In-Pt) double layer so that is lowered.

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