JP5688794B2 - Method and apparatus for producing nanomaterial array structure - Google Patents

Description

  The present invention relates to the field of controlling the alignment of nanomaterials.

  When light is irradiated to a system in which two nanomaterials are close to a scale below the wavelength of light, each of the nanomaterials is polarized by the light. The interaction between the two nanomaterials that are light-induced polarization causes attraction or repulsion between the materials. Specifically, when the vibration direction of the electric field of light, that is, the direction of polarization is parallel to the arrangement direction of the two substances, an attractive force acts between the two substances. On the other hand, when the direction of polarization is perpendicular to the arrangement direction of the two substances, a repulsive force acts between the two substances. This is the basic mechanism of the photoinduced force between substances.

  A method for manipulating nanomaterials using such a mechanism is disclosed in, for example, JP-T-2006-027863 (Patent Document 1). According to Patent Document 1, a nanomaterial group composed of a plurality of nanomaterials is irradiated with light that resonates with the electronic excitation level of the nanomaterial. According to the above method, the attractive force or repulsive force acting between the nanomaterials by changing the polarization direction of the light is used for the manipulation of the nanomaterials.

JP 2006-027863 Publication

  Depending on the balance between repulsive force and attractive force generated between atoms, the crystal structure varies. Similarly, it is expected that composites of nanomaterials having various structures can be created by utilizing attractive and repulsive forces generated between nanomaterials by light-induced forces. Thereby, it can also be expected to produce a nanomaterial composite having a new function.

  Patent Document 1 discloses light polarized in the vertical (vertical) direction and light polarized in the horizontal direction as polarized light for manipulating the nanomaterial. That is, Patent Document 1 discloses a method for manipulating nanomaterials using light polarized in one direction. However, in order to realize diversification of the structure of the nanocomposite material, it is preferable that light other than the above-described polarized light can also be used for producing the nanocomposite material.

  An object of the present invention is to provide a technique for controlling the arrangement of a plurality of nanomaterials.

  According to one aspect of the present invention, a nanomaterial array control method includes: preparing a nanomaterial population including a plurality of nanomaterials; and irradiating the nanomaterial population with axially symmetric polarized light that is polarized symmetrically with respect to an optical axis. Generating a photo-induced force in the plurality of nanomaterials, thereby arranging the plurality of nanomaterials.

  Preferably, the step of arranging the plurality of nanomaterials includes a step of controlling a spot diameter of the axially symmetric polarized light in order to control the photoinduced force.

Preferably, the nanomaterial arrangement control method further includes a step of preparing a substrate. Arranging the plurality of nanomaterials includes arranging a plurality of nanomaterials on the substrate.

  According to another aspect of the present invention, an apparatus for controlling the arrangement of nanomaterials generates a plurality of nanomaterials with axially symmetric polarized light that is polarized symmetrically with respect to the optical axis in order to generate photoinduced force in the plurality of nanomaterials. A light source for irradiating a nanomaterial group including a control unit that controls axially symmetric polarized light so that a plurality of nanomaterials are arranged by light-induced force.

  Preferably, the control unit controls the spot diameter of the axially symmetric polarized light in order to control the light induced force.

Preferably, the control unit arranges a plurality of nanomaterials on the substrate.
According to still another aspect of the present invention, a method of manufacturing a nanomaterial array structure includes a step of preparing a nanomaterial population including a plurality of nanomaterials, and nanosymmetrically polarized light that is polarized symmetrically with respect to an optical axis. Irradiating the group of materials to generate a photo-induced force in the plurality of nanomaterials, thereby arranging the plurality of nanomaterials.

  Preferably, the step of arranging the plurality of nanomaterials includes a step of controlling a spot diameter of the axially symmetric polarized light in order to control the photoinduced force.

  Preferably, the manufacturing method further includes a step of fixing a plurality of nanomaterials arranged by axisymmetric polarization.

  According to still another aspect of the present invention, the apparatus for manufacturing a nanomaterial array structure includes a plurality of axially symmetric polarizations that are polarized symmetrically with respect to the optical axis in order to generate a photo-induced force in the plurality of nanomaterials. A light source that irradiates a nanomaterial group including the nanomaterial, and a control unit that controls axisymmetric polarization so that a plurality of nanomaterials are arranged by light-induced force.

  Preferably, the control unit controls the spot diameter of the axially symmetric polarized light in order to control the light induced force.

Preferably, the controller fixes a plurality of nanomaterials arranged with axially symmetric polarization.
According to still another aspect of the present invention, a method for simulating the arrangement of nanomaterials sets an initial condition of a plurality of nanomaterials, and sets a condition for axially symmetric polarization for controlling the arrangement of the plurality of nanomaterials And a step of simulating the arrangement of the plurality of nanomaterials based on the photo-induced force generated in the plurality of nanomaterials by the axially symmetric polarized light applied to the plurality of nanomaterials.

  Preferably, the step of simulating includes a step of changing a spot diameter of the axially symmetric polarized light.

  According to still another aspect of the present invention, an apparatus for simulating the arrangement of nanomaterials includes a first setting unit for setting initial conditions of a plurality of nanomaterials, and an axially symmetric polarization for controlling the arrangement of the plurality of nanomaterials. A second setting unit for setting the conditions of the above, an array simulation unit for simulating the array of the plurality of nanomaterials based on the photo-induced force generated in the plurality of nanomaterials by the axially symmetric polarized light irradiated to the plurality of nanomaterials, Is provided.

Preferably, the simulation unit changes the spot diameter of the axially symmetric polarized light.
Preferably, the axially symmetric polarization is light having an energy lower than the resonance energy of a single nanomaterial.

Preferably, the axially symmetric polarization is light having an energy higher than the resonance energy of a single nanomaterial.

Preferably, the plurality of nanomaterials are present in either free space or a flowable medium.
Preferably, the axially symmetric polarized light is radial polarized light.

Preferably, the axially symmetric polarized light is azimuth polarized light.
Preferably, the nanoparticles are metal nanoparticles.

  ADVANTAGE OF THE INVENTION According to this invention, the technique for diversifying the arrangement | sequence structure of a nanomaterial can be provided.

It is a figure for demonstrating a single particle model. It is the figure which showed the result of having calculated the energy spectrum of the force which acts on a single particle (in a vacuum). It is a 1st figure for demonstrating a two-particle model. It is the figure which showed the calculation result of the light energy spectrum of the 2 particle | grain model shown by FIG. 3 (in a vacuum). It is a 2nd figure for demonstrating a two-particle model. It is the figure which showed the calculation result of the light energy spectrum of the 2 particle | grain model shown by FIG. 5 (in a vacuum). It is a figure for demonstrating the electric field intensity distribution of radial polarization, and the direction of an electric field vector. It is a figure for demonstrating the electric field intensity distribution of azimuth polarization, and the direction of an electric field vector. It is a figure for demonstrating the generation principle of radial polarization. It is a figure for demonstrating the generation principle of azimuth polarization. It is the figure explaining the position of the single nanoparticle in the beam waist surface of an axially symmetric polarization vector laser beam. It is the figure which showed the intensity distribution of the electric field in case a beam spot diameter is set to 800 nm. It is the figure which showed the intensity distribution of the electric field in case a beam spot diameter is set to 500 nm. It is the figure which showed the result of having calculated the force which acts on the particle | grains shown by FIG. It is the figure which showed the result of having calculated the force which acts on the particle | grains shown by FIG. It is a figure for demonstrating the interaction between these two particles which arises by irradiation of the radial polarization beam to two nanoparticles. It is the figure which showed the result of having calculated the force which acts on the two nanoparticles arrange | positioned according to the pattern A shown in FIG. 16 (room temperature water). It is the figure which showed the result of having calculated the force which acts on the two nanoparticles arrange | positioned according to the pattern B shown in FIG. 16 (room temperature water). It is the figure which showed the result of having calculated the force which acts on the two nanoparticles arrange | positioned according to the pattern A shown in FIG. 16 (room temperature water). It is the figure which showed the result of having calculated the force which acts on the two nanoparticles arrange | positioned according to the pattern B shown in FIG. 16 (room temperature water). It is a figure for demonstrating the interaction between two particles which arises by irradiation of an azimuthal polarized beam to two particles. It is the figure which showed the result of having calculated the force which acts on the two nanoparticles arrange | positioned according to the pattern A shown in FIG. 21 (room temperature water). It is the figure which showed the result of having calculated the force which acts on the two nanoparticles arrange | positioned according to the pattern B shown in FIG. 21 (room temperature water). It is the figure which showed the result of having calculated the force which acts on the two nanoparticles arrange | positioned according to the pattern A shown in FIG. 21 (room temperature water). It is the figure which showed the result of having calculated the force which acts on the two nanoparticles arrange | positioned according to the pattern B shown in FIG. 21 (room temperature water). It is the figure which showed the result which simulated the arrangement | sequence of two nanoparticles by polarization (in normal temperature water). It is the figure which showed the result which simulated the arrangement | sequence of four nanoparticles by polarization (in normal temperature water). It is a figure explaining the hardware constitutions of the computer 100 which performs the simulation method which concerns on embodiment of this invention. 2 is a block diagram showing a functional configuration of a CPU 120. FIG. It is a flowchart which shows an example of the flow of a process of the simulation method which concerns on embodiment of this invention. It is the figure which showed the structure of the manufacturing apparatus of the nanomaterial arrangement | sequence structure provided with the nanomaterial arrangement | sequence control apparatus which concerns on embodiment of this invention. It is the figure which showed the structural example of the light source 201 shown by FIG. FIG. 32 is a flowchart for explaining a nanomaterial arrangement control method and a nanomaterial arrangement structure production method by the production apparatus shown in FIG. 31. It is the figure which showed the structural example of the nanomaterial arrangement | sequence structure formed by irradiating a radial polarization to a nanomaterial group. It is the figure which showed the structural example of the nanomaterial arrangement | sequence structure formed by irradiating azimuth polarized light to a nanomaterial group. It is the figure which showed the model for calculating the absorption spectrum of the nano array structure produced | generated by radial polarization. It is the figure which showed the calculation result of the absorption spectrum of the nano-material arrangement | sequence structure shown by FIG. 36 (room temperature water). It is the figure which showed the model for calculating the absorption spectrum of the nano array structure produced | generated by azimuth polarization. It is the figure which showed the calculation result of the absorption spectrum of the nano-material arrangement | sequence structure shown by FIG. 38 (room temperature water). It is the figure which showed the example of application of the manufacturing apparatus which concerns on embodiment of this invention. It is a schematic diagram of the 1st example of the structure manufactured by the manufacturing apparatus 220 shown by FIG. It is a schematic diagram of the 2nd example of the structure manufactured by the manufacturing apparatus 220 shown by FIG. It is the schematic diagram which showed the structural example of the plasmonic solar cell.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

In the present invention and its embodiments, “nanomaterial” includes particles, structures, etc. having a size on the order of nanometers. “Nanometer order” includes the range of 1 to several hundred nanometers, typically in the range of 1 to 100 nm. According to the embodiment of the present invention, in a nanomaterial having a size of 1 to 100 nm, the force acting on the nanomaterial when a light resonance phenomenon occurs is equal to 10 ² of the force when there is no light resonance phenomenon. -10 to ^5- fold increase.

  In the present invention and its embodiments, the “photoresponsive nanomaterial” means a nanomaterial in which a large light-induced polarization is caused by light irradiation. Photoresponsive nanomaterials include, but are not limited to, organic polymers, semiconductor quantum dots, metal nanoparticles, carbon nanotubes, and the like. Light-induced polarization is an electrical polarization of a substance that is caused by the movement of electrons in the substance being excited by light. In the following, metal nanostructures will be described as one exemplary form of photoresponsive nanomaterial.

  In the present invention and its embodiments, “photo-induced force” is used as a general term for dissipative force, gradient force, and inter-material photo-induced force. A dissipative force is a force generated by imparting momentum of light to a substance in a dissipative process such as light scattering or light absorption. The gradient force is a force that moves a substance to a stable point of an electromagnetic potential when the substance in which light-induced polarization occurs is placed in a non-uniform electromagnetic field. The inter-substance photo-induced force is the sum of a force caused by a longitudinal electric field and a force caused by a transverse electric field (radiation field) generated from induced polarization in a plurality of photo-excited substances. Depending on the optical frequency and the characteristics of the excitation light (polarized light, phase, etc.), the force generated between a plurality of substances can be switched between repulsive force and attractive force.

  In the present invention and its embodiments, “resonant light” means light that causes light-induced polarization in a nanomaterial upon incidence on the nanomaterial. Typically, the resonant light is light that resonates with the electronic excitation level of the nanomaterial.

  In the present invention and its embodiments, the term “polarized light” means an electric field vector perpendicular to the propagation direction of the optical electromagnetic wave.

  In the present invention and its embodiments, “axially symmetric polarized light” means light polarized in an axially symmetric manner with respect to the optical axis. The “optical axis” may be read as the light propagation direction.

  In the present invention and its embodiments, the term “nanomaterial population” means a system comprising at least two nanomaterials. In the present invention, the “nanomaterial population” includes a population of a plurality of nanomaterials that gather to interact by irradiation with resonance light.

  In the present invention and its embodiments, the term “nanomaterial array structure” means a structure formed by disposing at least two nanomaterials at intervals of less than or equal to the light wavelength.

  In the present invention and its embodiments, “medium” means an environment in which nanomaterials exist. The type of medium is not particularly limited as long as the nanomaterial can move freely. The medium is not limited to a substance, and in the present invention and its embodiments, a vacuum can also be included as a “medium”. Therefore, in the present invention and its embodiments, nanomaterials may exist in free space or in a flowable medium. The fluid medium is, for example, a liquid. In the following description, it is assumed that the nanomaterial population exists in a liquid.

  In this specification, “energy” and “frequency (or angular frequency)” are interchangeable. According to quantum mechanics, a relationship of E = h / 2π × ω (h is Planck's constant) is established between the energy E and the angular frequency ω. Further, the angular frequency ω and the frequency f have a relationship of ω = 2πf. Therefore, in this specification, “energy” and “frequency (or angular frequency)” are interchangeable.

In the following description, the term “frequency” includes both the frequency f and the angular frequency ω unless it is necessary to distinguish between the frequency f and the angular frequency ω. In addition, since the wavelength λ is the reciprocal of the frequency f, “energy” and “wavelength” can be interchanged according to this relationship.

  The temperature of the environment where the nanomaterial group exists is, for example, room temperature (298K). However, the environmental temperature may be normal temperature or less. By reducing the environmental temperature, it is possible to reduce the thermal influence on the nanomaterial in the environment where the nanomaterial population exists, typically the Brownian motion by the thermally moving molecules.

<Photo-induced force applied to metal nanostructure>
Assume that the metal nanostructure is a spherical cell. In this case, the response photoelectric field can be expressed as an integral form of the Maxwell equation. The electric field E _i is expressed according to the following equation (1).

i and j are the particle numbers of the spherical cells. M and L are quantities related to self-interaction.
It is assumed that the susceptibility and electric field distribution inside each metal structure are flat. The induced polarization Pi is expressed according to the following formula (2).

  A Drude model is applied to the susceptibility χ. The susceptibility χ is expressed according to the following equation (3).

χ _b represents the background susceptibility, ω _p represents the plasma energy, γ represents the non-radiative relaxation constant, and V _f represents the electron velocity on the Fermi surface. The non-radiative relaxation constant is a value indicating relaxation from light to other than light (for example, heat).

  On the other hand, the photoinduced force is generally expressed by the following formula (4) (T. Iida and H. Ishihara, Phys. Rev. B 77, 245319 (2008)).

Induced polarization P _i and response electric field E _i expressed according to the above equations (2) and (3) are substituted into equation (4). Thereby, the photo-induced force is expressed according to the following formula (5).

G represents the Green function.
The first term on the right side of Equation (5) represents the light-induced force or gradient force caused by incident light, and the second term represents the inter-material light-induced force. The gradient force due to incident light is proportional to the light intensity gradient. On the other hand, the inter-substance light-induced force is proportional to the light intensity. For this reason, the balance between the light intensity gradient and the inter-substance light-induced force can be adjusted by adjusting the spot diameter of the incident light.

Next, a single particle model is assumed. In this case, assuming that the background susceptibility χ _b = 0 in order to discuss the essence of polarization and photo-induced force under irradiation with resonant light, the polarization P is expressed according to the following equation (6) (later embodiments) Then, a non-zero finite value is used for the background susceptibility χ _b ).

(−S ^(R) (ω, a)) represents the resonance frequency of the localized surface plasmon (LSP). ω _p ² S ^(I) (ω, a) represents a radiation relaxation rate. The radiation relaxation rate is a constant indicating the relaxation force when the localized surface plasmon returns to light. Here, S = (ML / K ² ), and when the particle size is small, S ^(R) is approximately −1/3.

  FIG. 1 is a diagram for explaining a single particle model. Referring to FIG. 1, light 5 (plane wave) is incident on a single particle 1. The propagation direction of the light 5 is the x direction, and the polarization direction of the light 5 (the direction of the electric field vector) is the y direction. When the light 5 is incident on the particle 1, a force Fx along the x direction is generated on the particle 1.

FIG. 2 is a diagram showing a result of calculating an energy spectrum of a force acting on a single particle. With reference to FIG. 2, the vertical axis of the graph indicates the magnitude of the force Fx (see FIG. 1) acting on the particle 1, and the horizontal axis indicates the energy (frequency) of the light 5. In this calculation, the electric field strength is 5 (MW / cm ² ), the plasma frequency is 8.958 (eV), γ = 72.3 (meV), and the relative dielectric constant ε _b = 1 of the background (background) Between the susceptibility χ _b and the relative dielectric constant ε _b of the background is χ _b = ε _b −1). The medium was a vacuum. The particle size was varied between 10 (nm), 20 (nm) and 30 (nm). As shown in FIG. 2, as the particle size increases, the energy when the intensity of the force Fx reaches the peak shifts to the lower energy side and the peak value of the force Fx increases.

  FIG. 3 is a first diagram for explaining the two-particle model. Referring to FIG. 3, particles 1 and 2 are arranged along the y direction. An axis Ax indicates an axis connecting the centers of the particles 1 and 2.

  Light 5 is incident on the particles 1 and 2. The polarization direction of the light 5 is the y direction. That is, the direction of polarization of the light 5 is a direction parallel to the axis Ax connecting the centers of the particles 1 and 2. In this case, polarization occurs in each of the particles 1 and 2 along a direction parallel to the direction of polarization of the light 5.

  FIG. 4 is a diagram showing the calculation result of the light energy spectrum of the two-particle model shown in FIG. Referring to FIG. 4, the vertical axis of the graph indicates the force acting on each of particles 1 and 2, and the horizontal axis of the graph indicates the energy (frequency) of light 5. In this calculation, the radii of the particles 1 and 2 are both 20 (nm), and the distance between the particles 1 and 2 is 50 (nm). The energy value corresponding to the peak value of the force acting on each of the particles 1 and 2 is about 0.039 (eV) lower than the resonance energy of a single particle. This energy difference corresponds to the binding energy of the polariton molecule.

While a negative force acts on the particle 1, a positive force acts on the particle 2. For this reason, as shown in FIG. 3, an attractive force acts between the particles 1 and 2. The polarization P in this case is expressed according to the following equation (7), assuming that the background susceptibility χ _b = 0 as in the derivation of the equation (6).

  FIG. 5 is a second diagram for explaining the two-particle model. Referring to FIG. 5, light 5 polarized in a direction perpendicular to the direction of axis Ax is incident on particles 1 and 2. Each of the particles 1 and 2 is polarized along a direction parallel to the polarization direction of the light 5. That is, the direction of polarization is perpendicular to the direction of the axis Ax of the particles 1 and 2.

  FIG. 6 is a diagram showing the calculation result of the light energy spectrum of the two-particle model shown in FIG. Referring to FIG. 6, the vertical axis of the graph indicates the force acting on each of particles 1 and 2, and the horizontal axis of the graph indicates the energy (frequency) of light 5. In this calculation, the radii of the particles 1 and 2 are both 20 (nm), and the distance between the particles 1 and 2 is 50 (nm). As shown in FIG. 6, the energy value corresponding to the peak value of the force acting on each of the particles 1 and 2 is about 0.0095 (eV) larger than the resonance energy of a single particle. This energy difference corresponds to the antibonding energy of the polariton molecule.

The directions of polarization of the particles 1 and the particles 2 are equal to each other. Therefore, as shown in FIG. 5, repulsive force is generated between the particles 1 and 2. The polarization P in this case is expressed according to the following equation (8). In the derivation, the background susceptibility χ _b = 0 is set in the same manner as in equations (6) and (7).

In the model of FIG. 3, since the polarization direction of the light 5 is the y direction, the function G _yy is used in Equation (7). On the other hand, since the polarization direction of the light 5 is the z direction in the model of FIG. 5, the function _Gzz is used in the equation (8).

<Arrangement control of metal nanostructures by axially symmetric polarization>
In the embodiment of the present invention, the arrangement of a plurality of nanomaterials is controlled by irradiating a plurality of nanomaterials each having photoresponsiveness with axially symmetric polarization (Axially-Symmetric Polarization). When the photoresponsiveness of a nanomaterial has polarization dependence, it is possible to cause the nanomaterial to have a mechanical action different from linearly polarized light or circularly polarized light by irradiating the nanomaterial with axially symmetric polarized light. .

  Axisymmetric polarization is classified into radial polarization and azimuth polarization depending on the direction of the electric field vector. FIG. 7 is a diagram for explaining the electric field intensity distribution of radial polarization and the direction of the electric field vector. FIG. 8 is a diagram for explaining the electric field intensity distribution of the azimuth polarized light and the direction of the electric field vector. With reference to FIGS. 7 and 8, in the case of radial polarization, the direction of the electric field is the radial direction. On the other hand, in the case of azimuth polarization, the direction of the electric field is the azimuth direction.

In the case of an axially symmetric polarization vector beam, the electric field intensity | E ² | becomes zero at the center of the beam. For this reason, in both the case of radial polarization and azimuth polarization, the electric field intensity distribution is a donut-shaped intensity distribution.

Although not shown in FIGS. 7 and 8, the z-axis is an axis that passes through the intersection (origin) of the x-axis and the y-axis and is perpendicular to the paper surface. The z-axis corresponds to the optical axis of the axisymmetric polarized vector beam. Hereinafter, the position on the z-axis where the spot diameter of the vector beam is the smallest is defined as z = 0, and this position is referred to as a beam waist. w ₀ is the spot diameter of the beam at the position of the beam waist.

FIG. 9 is a diagram for explaining the principle of generation of radial polarization. FIG. 10 is a diagram for explaining the principle of generation of azimuth polarized light. With reference to FIGS. 9 and 10, axisymmetric polarization vector laser light can be generated by coherent superposition of two TEM ₀₁ Laguerre Gaussian beams with parallel or orthogonal polarization.

  In order to enhance the light-induced polarization of the nanomaterial, it is preferable that the axially symmetric polarized vector laser light is introduced into the nanomaterial after being narrowed down to the size of the wavelength. By arranging the nanomaterial having photoresponsiveness on the beam waist surface, the light-induced polarization generated in the nanomaterial can be enhanced. Below, the metal nanoparticle on a beam waist surface is demonstrated.

FIG. 11 is a diagram illustrating the position of a single nanoparticle in the beam waist plane of an axially symmetric polarized vector laser beam. Referring to FIG. 11, particles 1a, 1b, 1c are arranged on the x-axis. The x coordinates of the particles 1a, 1b, and 1c are set to x1, x2, and x3, respectively. x2 indicates a position where the intensity of the electric field is substantially maximum. The coordinate x1 indicates a position closer to the beam center than the coordinate x2. On the other hand, the coordinate x3 indicates a position farther from the beam center than the coordinate x2.

  FIG. 12 is a diagram showing the intensity distribution of the electric field when the beam spot diameter is set to 800 nm. FIG. 13 is a diagram showing an electric field intensity distribution when the beam spot diameter is set to 500 nm. With reference to FIG. 12 and FIG. 13, the gradient of the electric field at coordinates x1, x3 is increased by reducing the beam spot diameter.

  FIG. 14 is a diagram showing the result of calculating the force acting on the particles shown in FIG. FIG. 15 is a diagram showing the result of calculating the force acting on the particles shown in FIG. In these calculations, the medium is assumed to be water, but the same results as those shown in FIGS. 14 and 15 can be obtained for particles in vacuum.

  Referring to FIG. 12 and FIG. 14, light having an energy lower than the resonance energy (about 2.2349 (eV)) is irradiated to the particle located at the coordinate x1 (370 nm). In this case, a positive force acts on the particle. Thereby, the particles are attracted from the coordinate x1 to a place where the electric field strength is higher. On the other hand, when light having a higher energy than the resonance energy is irradiated onto the particle located at the coordinate x1, a negative force acts on the particle. As a result, the particles are pushed out from the coordinate x1 to a position where the electric field intensity is smaller. The particles therefore move towards the center of the beam.

  When light having energy lower than the resonance energy is irradiated to the particle located at the coordinate x3 (900 nm), a negative force acts on the particle. As a result, the particles are attracted to a place where the electric field strength is strong. On the other hand, when light having an energy higher than the resonance energy is irradiated to the particle located at the coordinate x3, a positive force acts on the particle. As a result, the particles are pushed out from the coordinate x3 to a place where the electric field strength is smaller. The particles are therefore farther from the center of the beam.

  The particle located at the coordinate x2 (570 nm) is located at the place where the electric field strength is the largest. When a negative force acts on the particle by light having energy lower than the resonance energy, the gradient force approaches zero at x2 and becomes a stable region of the electromagnetic potential, so that the particle is supplemented in the vicinity of x2. On the other hand, when a positive force is applied to the particle by light having energy higher than the resonance energy, the particle is pushed near the center of the beam having a low intensity or outside the beam.

  FIG. 15 shows a result similar to the result shown in FIG. The particle at the coordinate x1 (200 nm) moves to a position where the electric field strength is high by light having energy lower than the resonance energy, while being pushed out to a position where electric field strength is higher than the resonance energy. The particle at the coordinate x3 (600 nm) moves to a position where the electric field strength is high by light having an energy higher than the resonance energy, and is pushed out to a position where the electric field strength is lower by light having an energy lower than the resonance energy. In the case of a particle located at the coordinate x2 (350 nm), a positive force acts on the particle by light having energy lower than the resonance energy. Thus, the particle moves from the coordinate x2 to the outside of the beam. On the other hand, a negative force acts on the particle by light having an energy higher than the resonance energy. Therefore, the particle moves from the coordinate x2 to the center of the beam.

12 to 15 show the following. By irradiating a plurality of particles with an axially symmetric polarized vector beam having energy lower than the resonance energy of the particles, the plurality of particles can be collected at a place where the electric field strength is large. Conversely, by irradiating a plurality of particles with an axially symmetric polarized vector beam having energy higher than the resonance energy of the particles, the plurality of particles can be moved away from a place where the electric field strength is large. By reducing the beam spot diameter, the gradient of force against energy is increased. Therefore, the gradient force acting on the particles can be increased. One inter-substance light-induced force is proportional to the intensity itself at the position where the particles exist, and therefore has a different dependence on the change in the intensity gradient from the gradient force. That is, the magnitude of the force acting on the particles can be controlled by the beam spot diameter. By utilizing these characteristics, it is possible to control the balance between the gradient force caused by incident light and the light-induced force between substances.

  FIG. 16 is a diagram for explaining the interaction between the two nanoparticles caused by irradiation of the two nanoparticles with a radial polarized beam. Referring to FIG. 16, each of pattern A and pattern B shows a pattern of arrangement of particles 1 and 2. Pattern A is a pattern in which the distance from the optical axis to particle 1 and the distance from the optical axis to particle 2 are both equal. Pattern B is a pattern in which the distance from the optical axis to the particle 1 is larger than the distance from the optical axis to the particle 2.

  In the case of the pattern A, the axis connecting the center of the particle 1 and the center of the particle 2 is orthogonal to the polarization direction (electric field direction). For this reason, repulsive force is generated between the particles 1 and 2. On the other hand, in the case of the pattern B, the axis connecting the center of the particle 1 and the center of the particle 2 is parallel to the polarization direction. For this reason, an attractive force is generated between the particles 1 and 2.

FIG. 17 is a diagram showing a result of calculating a force acting on two nanoparticles arranged according to the pattern A shown in FIG. FIG. 18 is a diagram showing a result of calculating a force acting on two nanoparticles arranged according to the pattern B shown in FIG. The results shown in FIG. 17 indicate that the spot diameter w ₀ is 800 nm, the distance ρ from the optical axis to each of the particles 1 and 2 is 565.55 nm, and the center of the particle 1 and the particle 2 This was obtained by setting the distance r to the center r = 50 (nm) and the resonance energy of a single particle to 2.2349 (eV). The results shown in FIG. 18 indicate that the spot diameter w ₀ is 800 (nm), the distance ρ1 from the optical axis to the particle 1 is 600 (nm), the distance ρ2 from the optical axis to the particle 2 is 550 (nm), The distance r between the center of the particle 1 and the center of the particle 2 was set to r = 50 (nm), and the resonance energy of a single particle was set to 2.2349 (eV). In these calculations, the medium is assumed to be water, but the same results as those shown in FIGS. 17 and 18 can be obtained for particles in a vacuum. As shown in FIGS. 17 and 18, a repulsive force is generated between the particles 1 and 2 arranged according to the pattern A, whereas an attractive force is generated between the particles 1 and 2 arranged according to the pattern B.

FIG. 19 is a diagram showing a result of calculating a force acting on two nanoparticles arranged according to the pattern A shown in FIG. FIG. 20 is a diagram illustrating a result of calculating a force acting on two nanoparticles arranged according to the pattern B illustrated in FIG. The results shown in FIG. 19 indicate that the spot diameter w ₀ is 500 (nm), the distance ρ from the optical axis to each of the particles 1 and 2 is 350.89 (nm), the center of the particle 1 and the center of the particle 2 The distance r is 50 (nm), and the resonance energy of a single particle is 2.2349 (eV). The results shown in FIG. 20 indicate that the spot diameter w ₀ is 500 (nm), the distance ρ1 from the optical axis to the particle 1 is 400 (nm), the distance ρ2 from the optical axis to the particle 2 is 350 (nm), The distance r between the center of the particle 1 and the center of the particle 2 was set to r = 50 (nm), and the resonance energy of a single particle was set to 2.2349 (eV). Since other conditions are the same as the conditions when the calculation results shown in FIGS. 17 and 18 are obtained, detailed description will not be repeated. As shown in FIGS. 19 and 20, even when the spot diameter w ₀ is changed from 800 (nm) to 500 (nm), the inter-substance photoinduced force is the particles 1 and 2 arranged according to the pattern A. Between the particles 1, 2 arranged according to the pattern B
As shown in FIGS. 14 and 15, since the magnitude of the gradient force varies depending on the spot diameter, different arrangement structures can be created by controlling the spot diameter.

  FIG. 21 is a diagram for explaining an interaction between two particles caused by irradiation of two particles with an azimuth polarized beam. Referring to FIG. 21, in the case of pattern A, the axis connecting the center of particle 1 and the center of particle 2 is parallel to the polarization direction (direction of the electric field). For this reason, an attractive force is generated between the particles 1 and 2. On the other hand, in the case of the pattern B, the axis connecting the center of the particle 1 and the center of the particle 2 is perpendicular to the polarization direction. For this reason, repulsive force is generated between the particles 1 and 2. That is, in the case of an azimuth polarized beam, a result opposite to the result of the radial polarized beam is produced. The conditions for obtaining the calculation results of FIGS. 22 to 25 described below are the same as the conditions for obtaining the calculation results of FIGS.

FIG. 22 is a diagram showing a result of calculating a force acting on two nanoparticles arranged according to the pattern A shown in FIG. FIG. 23 is a diagram showing a result of calculating a force acting on two nanoparticles arranged according to the pattern B shown in FIG. The spot diameter w ₀ was set to 800 (nm).

  As shown in FIGS. 22 and 23, an attractive force is generated between the particles 1 and 2 arranged according to the pattern A, whereas a repulsive force is generated between the particles 1 and 2 arranged according to the pattern B.

FIG. 24 is a diagram showing a result of calculating a force acting on two nanoparticles arranged according to pattern A shown in FIG. FIG. 25 is a diagram showing a result of calculating a force acting on two nanoparticles arranged according to the pattern B shown in FIG. It should be noted, was the spot diameter _{w 0} and 500 (nm). As shown in FIG. 24 and FIG. 25, even when the spot diameter w ₀ is changed, the attractive force is generated between the particles 1 and 2 arranged according to the pattern A, whereas the particles arranged according to the pattern B. A repulsive force is generated between 1 and 2.

  Thus, the force (attraction and repulsion) generated between the particles 1 and 2 can be controlled by controlling the polarization direction. As a result, the particles 1 and 2 can be aligned.

  FIG. 26 is a diagram showing the result of simulating the arrangement of two nanoparticles by polarized light. Referring to FIG. 26, by irradiating two nanoparticles with linearly polarized light polarized in the y direction, the two particles are aligned in a direction substantially parallel to the y direction at the position of the beam waist. FIG. 26 shows that even when a random force due to thermal fluctuation exists, two particles are arranged along a direction parallel to the polarization direction due to the balance between the electric double layer repulsive force and the light-induced force (attractive force and repulsive force). It shows that you can.

  The results shown in FIG. 26 are obtained under the following conditions. The nanoparticles were gold nanoparticles, and the diameter of the particles was 40 (nm). Furthermore, the gold nanoparticles were assumed to be present in water at room temperature. The light intensity was 600 (mW), and the excitation wavelength was 1064 (nm), which is a non-resonant wavelength. Further, the spot diameter was set to 1000 (nm), the irradiation time of the laser beam was set to 0.02 (s), and the number of steps was set to 1000000 (steps). The particle trajectory is plotted).

  FIG. 27 is a diagram showing the result of simulating the arrangement of four nanoparticles by polarized light. The conditions for obtaining the result of FIG. 27 are the same as the conditions for obtaining the result of FIG. As shown in FIG. 27, even when the number of nanoparticles is increased from two to four, four particles can be arranged along a direction parallel to the polarization direction.

<Method and apparatus for simulating nanomaterial arrangement>
In one embodiment of the present invention, an array of a plurality of nanomaterials by light induced force is simulated. By simulating the arrangement of a plurality of nanomaterials, the structure of the nanomaterial arrangement structure can be predicted. By predicting the structure of the nanomaterial array structure, the properties of the nanomaterial array structure can be predicted. This increases the possibility of producing a nanocomposite having a new function.

  FIG. 28 is a diagram illustrating a hardware configuration of the computer 100 that executes the simulation method according to the embodiment of the present invention. Referring to FIG. 28, a computer 100 includes a computer main body 101, a flexible disk (hereinafter referred to as “FD”) drive 103, an optical disk drive 104, a communication interface 105, a monitor 106, a keyboard 107, and the like. And a mouse 108. The FD drive 103, the optical disc drive 104, the communication interface 105, the keyboard 107 and the mouse 108 are connected to the computer main body 101 via the bus 102.

The FD drive 103 reads information from the FD 113 and records information on the FD 113. The optical disc drive 104 reads information recorded on an optical disc such as a CD-ROM (Compact Disc Read-Only Memory) 114. Communication interface 105
Transmits and receives data to and from a device external to the computer 100 via a communication line (not shown).

The computer main body 101 includes a CPU (Central Processing Unit) 120 and a ROM.
A memory 121 including a (Read Only Memory) and a RAM (Random Access Memory) and a hard disk 122 are included. The CPU 120, the memory 121, and the hard disk 122 are connected to the bus 102.

  The hard disk 122 stores a parameter 130 for simulating the arrangement of a plurality of nanomaterials, a simulation program 131, and a simulation result 132. The hard disk 122 is an example of a direct access memory device, and other types of direct access memory devices may be used instead of the hard disk 122.

  The parameter 130 includes various parameters for simulating the arrangement of nanomaterials. As an example, the parameters 130 include the number of nanomaterials, the size of the nanomaterial (radius, volume, etc.), the distance between a plurality of nanomaterials, the light frequency, the light intensity (power), the polarization direction of the light, the spot diameter, It includes the irradiation time, the irradiation cycle, and the number of irradiations, the environmental temperature, the type of medium in which the nanomaterial exists, and the like. However, the types of parameters are not limited to these.

  A user can change the parameter 130 via an input device such as a keyboard 107 and a mouse 108. The parameter 130 may be supplied from an external database via the communication interface 105.

  The simulation program 131 is a program for simulating the arrangement of a plurality of nanomaterials based on the above parameters. The simulation program 131 may be supplied by a storage medium such as the FD 113 and the CD-ROM 114, or may be supplied from another computer via a communication line. The simulation result 132 includes an execution result of the simulation program 131.

The simulation program 131 is software executed by the CPU 120. When the CPU 120 executes the simulation program 131,
The computer 100 functions as a simulation device.

  FIG. 29 is a block diagram illustrating a functional configuration of the CPU 120. Referring to FIG. 29, CPU 120 includes an initial condition setting unit 150, a polarization condition setting unit 160, and an array simulation unit 170.

  The initial condition setting unit 150 sets initial states of a plurality of nanomaterials based on the parameter 130. For example, the initial condition setting unit 150 sets the number of nanomaterials, the initial position of the nanomaterial (or the interval between the plurality of nanomaterials), the size of the nanomaterial, the medium, and the environmental temperature.

  Based on the parameter 130, the polarization condition setting unit 160 sets conditions relating to axially symmetric polarization that is applied to a plurality of nanomaterials. For example, the polarization condition setting unit 160 sets a frequency, intensity (power), polarization direction, light propagation direction, spot diameter, irradiation time, irradiation cycle, number of irradiations, and the like. In order to set the polarization direction, either one of radial polarization and azimuth polarization may be selected. Alternatively, not only radial polarization and azimuth polarization but also linear polarization may be selected. By selecting linearly polarized light, the simulation model can be further simplified. When the user changes the condition of the axially symmetric polarization included in the parameter 130, the polarization condition setting unit 160 changes the condition related to the axially symmetric polarization based on the parameter 130.

  Based on the initial state of the plurality of nanomaterials set by the initial condition setting unit 150 and the condition of axially symmetric polarization set by the polarization condition setting unit 160, the array simulation unit 170 is configured according to the simulation program 131. Simulate the array. The array simulation unit 170 uses a formula (7) or a formula (8) based on a relationship between an axis connecting the centers of two nanomaterials and a polarization direction to generate a photo-induced force (two nanomaterials) generated in the nanomaterial. The attractive force or repulsive force generated between them, or the gradient force acting on the nanomaterial) and its magnitude are calculated. The array simulation unit 170 simulates the array of a plurality of nanomaterials based on the calculated photoinduced force and the force acting on the nanomaterial by the thermal fluctuation, and outputs the result as a simulation result 132.

  FIG. 30 is a flowchart showing an example of a processing flow of the simulation method according to the embodiment of the present invention. The process of this flowchart is executed by the computer 100 shown in FIG. It should be noted that the simulation method according to the embodiment of the present invention is not limited to being executed in the order shown in FIG. For example, the order of the processes may be changed as appropriate, and a plurality of processes may be executed in parallel.

  Referring to FIG. 30, in step S <b> 1, initial conditions for a plurality of nanomaterials are set based on parameter 130. In step S2, conditions regarding the axially symmetric polarization vector beam are set. In step S <b> 3, the array of nanomaterials is simulated according to the simulation program 131. In step S4, the simulation result 132 is output. When the process of step S4 ends, the entire process ends. When the computer 100 (simulation apparatus) executes the process shown in FIG. 30, the simulation results shown in FIGS. 26 and 27 can be obtained.

<Manufacture of nanomaterial array structure>
A nanomaterial arrangement control method according to an embodiment of the present invention includes a step of preparing a nanomaterial group composed of a plurality of nanomaterials, and a step of irradiating the nanomaterial with axially symmetric polarized light. Light-induced force is generated in the nanomaterial by irradiating the nanomaterial population with axially symmetric polarized light. By utilizing the force, the arrangement of nanomaterials is controlled. Note that the type of medium for the presence of the nanomaterial is not particularly limited.

  FIG. 31 is a diagram illustrating a configuration of a nanomaterial array structure manufacturing apparatus including the nanomaterial array control device according to the embodiment of the present invention. Referring to FIG. 31, manufacturing apparatus 200 according to the embodiment of the present invention includes light source 201, housing 202, nanomaterial group generation unit 203, medium supply unit 204, substrate fixing unit 205, and control. Unit 206.

  According to the present embodiment, the arrangement of nanomaterials can be controlled in a room temperature environment. Therefore, the housing 202 is not necessarily required for the nanomaterial arrangement control. According to the present embodiment, for example, the arrangement of nanomaterials can be controlled even in an environment in which a solution in which nanomaterials (for example, gold nanoparticles) are dispersed is sealed in a sample cell. Alternatively, the substrate 11 and the nanomaterial group 10 may be prepared by dropping a solution in which the nanomaterial (for example, gold nanoparticles) is dispersed onto the substrate 11.

  The light source 201 irradiates the nanomaterial group 10 with an axisymmetric polarized vector beam. The control unit 206 changes the condition of axially symmetric polarization emitted from the light source 201. For example, the spot diameter of the polarized beam irradiated on the nanomaterial group 10 is changed.

  FIG. 32 is a diagram showing a configuration example of the light source 201 shown in FIG. With reference to FIG. 32, the light source 201 includes a laser light source 211, a radial polarization converter 212, and a condensing optical system 213.

  The laser light source 211 generates linearly polarized laser light. The specific configuration of the laser light source 211 is not particularly limited, and a known laser light source used for manipulating nanomaterials can be used. For example, when controlling the arrangement of gold nanoparticles as described above, a laser light source (for example, an Nd: YAG laser) that generates laser light having a wavelength of 1064 (nm) can be used as the laser light source 211. In addition, for example, in order to change the photoinduced force under conditions close to the resonance conditions of the localized surface plasmon of the metal nanoparticles disclosed in the embodiment, a semiconductor laser having a wavelength in the range of 500 nm to 700 nm is used as the laser light source 211. It can also be used. The laser light source 211 is preferably a tunable laser so that the wavelength (energy, optical frequency) of the laser light can be changed. Thereby, light having an energy higher than the resonance energy of a single nanoparticle and light having an energy lower than the resonance energy can be generated.

  The radial polarization converter 212 converts the linearly polarized beam from the laser light source 211 into an axially symmetric polarized beam. For example, the radial polarization converter 212 is a polarization control device that includes a liquid crystal layer. The liquid crystal molecules contained in the liquid crystal layer change the alignment direction by an electric signal from the control unit 206. Linearly polarized light is incident on a liquid crystal layer containing liquid crystal molecules whose orientation direction is controlled. Thereby, linearly polarized light can be converted into radial polarized light or azimuth polarized light.

  The radial polarization converter 212 is preferably capable of switching between generation of radial polarization and generation of azimuth polarization. However, the radial polarization converter 212 may be capable of generating only one of radial polarization and azimuth polarization.

  The condensing optical system 213 collects the axially symmetric polarized beam from the radial polarization converter 212 and irradiates the nanomaterial group. The condensing optical system 213 is not particularly limited as long as it is a device that can change the spot diameter of the axially symmetric polarized beam. For example, a beam expander or a lens having a known configuration can be used.

Returning to FIG. 31, the manufacturing apparatus 200 may include a light source that generates linearly polarized light or circularly polarized light in addition to the light source 201 that generates axially symmetric polarized light. By irradiating the nanomaterial group 10 with different types of polarized light, various arrangements of nanomaterials can be realized.

  The nanomaterial group 10 is confined inside the housing 202. The size, shape, and the like of the housing 202 are not particularly limited as long as they can provide an appropriate environment for the nanomaterial group 10. The inside of the housing 202 may be a vacuum or may be filled with a liquid medium.

  The nanomaterial group generation unit 203 generates a nanomaterial group 10 composed of a plurality of nanomaterials. For example, the nanomaterial group generation unit 203 first generates a nanomaterial and then forms the nanomaterial group 10.

  The medium supply unit 204 supplies a medium into the housing 202. The type of the medium is not particularly limited, and is a fluid medium, for example. The kind of fluid medium is not particularly limited. When it is required to cool the inside of the housing 202, for example, liquid nitrogen, liquid helium, or the like may be used as the fluid medium. In addition, when the inside of the housing 202 needs to be in a state close to a vacuum, a vacuum pump can be used as the medium supply unit 204.

  The substrate fixing unit 205 fixes the substrate 11. In this embodiment, a nanomaterial array structure is manufactured by arranging a plurality of nanomaterials on the surface of the substrate 11. Although the kind of board | substrate 11 is not specifically limited, For example, a semiconductor substrate, a glass substrate, etc. can be used.

  The control unit 206 controls the light source 201, the nanomaterial group generation unit 203, and the medium supply unit 204. Specifically, the control unit 206 controls the condition of axially symmetric polarization emitted from the light source 201. This condition includes frequency (wavelength), intensity, polarization type, irradiation time, irradiation cycle, number of irradiations, and the like. However, the condition of axially symmetric polarization is not limited to the above condition. The control unit 206 further controls the generation of the nanomaterial group 10 by the nanomaterial group generation unit 203 (for example, the generation timing of the nanomaterial group 10, the concentration of the nanomaterial, etc.). Further, the control unit 206 controls medium supply (for example, supply amount, supply timing, etc.) by the medium supply unit 204. Further, the control unit 206 may execute a process for fixing the plurality of nanoparticles arranged on the substrate 11 to the substrate 11.

  Although not shown in FIG. 31, the manufacturing apparatus 200 detects display means (such as various displays) for presenting various types of information related to the array control of the nanomaterial group 10 to the operator, and a nanomaterial array structure. And means for keeping the temperature inside the housing 202 constant may be further provided. As such means, a known configuration can be used, and its operation can also be controlled by the control unit 206.

  FIG. 33 is a flowchart for explaining a nanomaterial arrangement control method and a nanomaterial arrangement structure production method using the production apparatus shown in FIG. 31. In addition, the arrangement | sequence control method and manufacturing method which concern on embodiment of this invention are not limited to what is performed according to the order shown in FIG. For example, the order of the processes may be changed as appropriate, and a plurality of processes may be executed in parallel.

  Referring to FIG. 33, in step S <b> 11, nanomaterial group generation unit 203 forms nanomaterial group 10. That is, the nanomaterial group 10 is prepared in step S11. The substrate 11 is prepared in advance prior to the processing in step S11.

  In step S <b> 12, the light source 201 generates an axially symmetric polarized vector beam and irradiates the nanomaterial group 10 with the axially symmetric polarized vector beam.

  In step S <b> 13, the control unit 206 controls the light source 201. Thereby, the axially symmetric polarization vector beam emitted from the light source 201 is controlled. By controlling the axially symmetric polarization vector beam, a light-induced force is generated in the plurality of nanomaterials. A plurality of nanomaterials are arranged on the surface of the substrate 11 by the photoinduced force.

  In step S <b> 14, the nanomaterial is fixed on the surface of the substrate 11. The process of step S14 may optionally be executed. Since a known method can be used as a method for fixing the nanomaterial on the surface of the substrate 11, detailed description thereof will not be repeated here. For example, the nanomaterial may be fixed to the surface of the substrate 11 using electrostatic interaction between the substrate 11 and the nanomaterial, or after a plurality of nanomaterials are arranged on the surface of the substrate 11. The surface may be coated with a thin film, and when the process of step S14 ends, the entire process ends.

  FIG. 34 is a diagram showing a structure example of a nanomaterial array structure formed by irradiating a nanomaterial group with radial polarized light. FIG. 35 is a diagram showing a structural example of a nanomaterial array structure formed by irradiating azimuth polarized light to a nanomaterial population. Referring to FIGS. 34 and 35, by irradiating the nanomaterial group 10 with light having energy lower than the resonance energy of a single nanomaterial, a force that attracts the nanomaterial to a portion where the electric field strength is strong works. When the radial polarized light is irradiated to the nanomaterial group, an attractive force works in the radial direction and a repulsive force works in the azimuth direction. As shown in FIG. 34, in the nanomaterial array structure 21, the central axis of the pair of particles 1 and 2 (axis corresponding to the axis Ax shown in FIGS. 3 and 5) is along the radial direction. , A pair of particles 1, 2 is arranged. Furthermore, a plurality of nanomaterials are arranged so as to be dense in the radial direction and sparse in the azimuthal direction.

  On the other hand, when azimuthal polarized light is irradiated onto a group of nanomaterials, repulsive force works in the radial direction and attractive force works in the azimuth direction. As shown in FIG. 35, in the nanomaterial array structure 22, the central axes of the pair of particles 1 and 2 are arranged along the azimuth direction. Furthermore, a plurality of nanomaterials are arranged so as to be sparse in the radial direction and dense in the azimuth direction.

  As described above, according to the embodiment of the present invention, the arrangement structure of nanomaterials can be changed by changing the type of axially polarized light. Furthermore, the balance between gradient force and attractive force (or repulsive force) can be changed by changing the spot diameter of the axisymmetric polarized vector beam. For this reason, it is also possible to create an array structure with different particle spacings.

  By changing the structure of the nanomaterial array structure, the characteristics of the structure can also be changed. Below, an absorption spectrum is shown as an example of the characteristic depending on the structure of the nanomaterial array structure.

FIG. 36 is a diagram showing a model for calculating the absorption spectrum of the nano-array structure generated by radial polarization. Referring to FIG. 36, let N be the number of particles arranged concentrically. When the number of particles in the arrangement direction is 1, the number of circles in which N particles are arranged is (N / l). .., J,... Are assigned to a plurality of particles arranged on the same circumference counterclockwise from the particles on the x-axis. Let θ _j be the angle at which the straight line extending from the center of the circle to the center of the j-th particle is the x axis. The angle θ _j is expressed according to the following equation (9).

θ _j = 8π (j−1) / N (9)
The coordinates (x _kj , y _kj ) of the j-th particle having the center on the k-th circumference from the inside are expressed according to the following equations (10) and (11), respectively.

x _kj = ρ _k cos θj (10)
y _kj = ρ _k sin θj (11)
FIG. 36 shows the configuration of the nanomaterial array structure when N = 48 and l = 12.

FIG. 37 is a view showing a calculation result of an absorption spectrum of the nanomaterial array structure shown in FIG. The particle diameter was set to 40 nm. In addition, the distance between the centers of two particles adjacent in the radial direction (= ρ _{k + 1, j} −ρ _{k, j} ) was set to 50 nm. Moreover, it set to (rho) _{1, j} = 275nm. θ _j−1 −θ _j−1 = π / 6.

  FIG. 37 also shows two absorption spectra of 48 nanoparticles arranged in a line for comparison with the absorption spectrum of the nanomaterial array structure (ie, the curve shown by RTEM). One of these two absorption spectra (ie, the curve indicated by Linear (parallel)) is the absorption spectrum of the linear structure for linearly polarized light that is polarized in a direction parallel to the array direction of the nanoparticles, and the other (ie, , A curve represented by Linear (perpendicular)) is an absorption spectrum of the linear structure with respect to linearly polarized light polarized in a direction perpendicular to the arrangement direction of the nanoparticles.

  The absorption spectrum of the linear structure shows that the absorption wavelength greatly depends on the polarization direction. On the other hand, the absorption spectrum of the structure created by radial polarization (curve shown by RTEM) absorbs linearly polarized light in various directions over a wide frequency band by densely arranging nanomaterials in the radial direction. Show what you can do.

  FIG. 38 is a diagram illustrating a model for calculating an absorption spectrum of a nanoarray structure generated by azimuth polarization. Referring to FIG. 38, N particles are arranged at a position where the electric field strength of azimuth polarized light is strongest. Therefore, N particles are arranged in an annular shape. Let the radius of this circle be ρ. FIG. 38 shows an example of the nano-array structure when N = 48.

  FIG. 39 is a diagram showing a calculation result of an absorption spectrum of the nanomaterial array structure shown in FIG. N was 48, the particle diameter was 40 nm, the center-to-center distance between two particles adjacent in the azimuth direction was 49.7 nm, and ρ = 380 nm. Further, θ = π / 24 was set.

  Similar to FIG. 37, FIG. 39 shows two absorption spectra of 48 nanoparticles arranged linearly (that is, a curve indicated by Linear (y-direction) and a curve indicated by Linear (z-direction)). Indicated. The absorption spectrum (ie, the curve shown by ATEM) of structures created by azimuth polarization can absorb linearly polarized light in various directions over a wide frequency band by densely arranging nanomaterials in the azimuth direction. Indicates.

  As described above, according to the embodiment of the present invention, the arrangement of a plurality of nanomaterials is controlled by the axially symmetric polarization vector beam. This makes it possible to manufacture a nanomaterial array structure that can efficiently absorb light polarized in various directions.

  FIG. 40 is a diagram showing an application example of the manufacturing apparatus according to the embodiment of the present invention. Referring to FIG. 40, the manufacturing apparatus 220 includes a light source 201, a control unit 206, a grating 222, a telescope 223, a mirror 224, an objective lens 225, an illuminator 226, and an eyepiece (eyepiece) 227. And a video camera 228.

  The grating 222 is a hologram generated by a computer, for example. The axially symmetric polarization vector beam from the light source 201 is divided into a plurality of beams traveling in an arbitrary direction by the grating 222. The plurality of beams pass through the telescope 223 and enter the objective lens 225 through the mirror 224. The objective lens 225 condenses the laser beam from the mirror 224. The nanomaterial population 10 exists on the surface of the substrate 11. The laser beam emitted from the objective lens 225 is applied to the nanomaterial group 10. Note that the light source 201 is controlled by the control unit 206. Thereby, the axially symmetric polarized vector beam emitted from the light source 201 is controlled. Further, a radial polarization converter 212 may be provided immediately after the light source 201.

  According to the configuration of FIG. 40, a plurality of axially symmetric polarization vector laser beams can be generated by controlling the hologram pattern of the grating 222. Thereby, a large number of nanomaterial array structures shown in FIGS. 34, 35, 36, and 38 can be generated on the surface of the substrate 11. Further, a radial polarization converter 212 (see FIG. 32) may be provided immediately after the light source 201. In this case, the single axially symmetric vector laser beam generated by the radial polarization converter 212 is reflected by the grating 222, so that the single axially symmetric vector laser beam is converted into a plurality of axially symmetric vector laser beams while preserving the polarization. Divide into Even with such a configuration, a large number of radial and concentric array structures shown in FIGS. 34, 35, 36, and 38 can be produced.

  FIG. 41 is a schematic view of a first example of a structure manufactured by the manufacturing apparatus 220 shown in FIG. Referring to FIG. 41, a plurality of nanomaterial array structures 21 are arranged on the surface of substrate 11. The configuration of the nanomaterial array structure 21 corresponds to the configuration shown in FIG. That is, each nanomaterial array structure includes a plurality of nanomaterials arranged radially. FIG. 42 is a schematic view of a second example of the structure manufactured by the manufacturing apparatus 220 shown in FIG. Referring to FIG. 42, a plurality of nanomaterial array structures 22 are arranged on the surface of substrate 11. The configuration of the nanomaterial array structure 22 corresponds to the configuration shown in FIG. The configuration of the nanomaterial array structure 22 corresponds to the configuration shown in FIG. That is, each nanomaterial array structure includes a plurality of nanomaterials arranged concentrically. It should be noted that only one kind of nanomaterial array structure (that is, only one of the nanomaterial array structure 21 and the nanomaterial array structure 22) is not limited to be arranged on the surface of the substrate 11. Both nanomaterial array structures 21 and 22 may be arranged on the surface of the substrate 11.

(Application examples)
According to the embodiment of the present invention, it can be used for array control of any kind of nanomaterial. For example, when local surface plasmon (LSP) in a metal nanoparticle is resonantly excited with light, a strong photoelectric field is generated in the vicinity of the surface of the metal nanoparticle, thereby showing strong light scattering and light absorption even at room temperature. In addition, since the optical spectrum changes sensitively depending on the arrangement state of the nanoparticle population, various applications of the nanomaterial arrangement structure are expected by designing the arrangement of the metal nanoparticles.

  Therefore, according to the embodiment of the present invention, it can be expected that various materials having different utilization forms of light are produced. Further, according to the embodiment of the present invention, it is possible to produce a material that can be used by converting light energy into another physical quantity with high efficiency by controlling the arrangement of nanomaterials using an axially symmetric polarized beam. I can expect.

Application examples of the nanomaterial array structure according to the embodiment of the present invention will be described below.
(1) Use for novel high-efficiency photoelectric conversion material and device Examples of the material or device include the following.

(A) Plasmonic solar cell having metal nanoparticles with controlled arrangement and photoresponse characteristics (b) Organic-inorganic hybrid artificial collection system with locally controlled photoelectric conversion characteristics (c) Photocurrent detection type Localized Surface Plasmon Biosensor FIG. 43 is a schematic diagram showing a configuration example of a plasmonic solar cell. Referring to FIG. 43, plasmonic solar cell 300 includes metal layer 302, n-type semiconductor layer 304 disposed on metal layer 302, and p-type semiconductor layer disposed on n-type semiconductor layer 304. 306 and a plurality of nanomaterial array structures 21 arranged on the surface of the p-type semiconductor layer 306. The nanomaterial array structure 21 includes a plurality of nanomaterials arranged radially. On the surface of the p-type semiconductor layer 306, instead of the plurality of nanomaterial array structures 21, a plurality of nanomaterial array structures 22 (each nanomaterial array structure 22 includes a plurality of nanomaterials arranged concentrically. Including) may be arranged. Furthermore, both the nanomaterial array structure 21 and the nanomaterial array structure 22 may be disposed on the surface of the p-type semiconductor layer 306.

  For example, in the examples described in the items (a) and (b) above, a wide light absorption band due to the electromagnetically coupled state of the localized surface plasmon can be used, and at a site that causes light-induced polarization with high efficiency. There is a possibility that an array structure of nanomaterials capable of concentrating light energy can be produced. Further, in the example described in item (c), there is a possibility that a sensor capable of detecting the biomolecule with high efficiency can be produced by the combination of the photoresponsive biomolecule and the plasmon.

(2) High-efficiency light-heat conversion material For example, there is a possibility that a material for photothermal therapy that converts light energy into heat energy with high efficiency can be created. For example, development of a material capable of locally heating a desired place and application of the material to a living body can be expected.

(3) Nano-optical device that transmits light energy as light As the above-mentioned optical device, for example, the following can be cited.

(D) Visible light metamaterial (e) Near-field nano-optical device (f) Nano-optoelectronic circuit In the case of (d), by appropriately designing the array of nano-materials, light having specific properties can be selectively selected There is a possibility that an optical filter that transmits, collects, or absorbs light can be produced.

  In the case of (e), there is a possibility that an optical interconnection for assisting the photoelectric conversion device can be produced by appropriately designing the arrangement of nanomaterials so that, for example, an aggregate of photofunctional molecules is formed.

  In the case of (g), there is a possibility that an optical interconnection for assisting the photoelectric conversion device can be produced by appropriately designing an array of carbon nanomaterials or quantum dots having desired quantum characteristics.

  As described above, according to the embodiment of the present invention, diversification of the structure of the nanocomposite material can be realized by controlling the arrangement of the plurality of nanomaterials using the axially symmetric polarization.

In the above embodiment, a plurality of nanomaterials are arranged on the substrate. That is, a two-dimensional array structure is produced. However, according to the present invention, a three-dimensional array structure can be produced. For example, in a flowable photo-curing resin or thermosetting resin, the array of nanoparticles is controlled by an axially symmetric polarized beam to trap the nanoparticles, and other light having a wavelength different from that of the axially symmetric polarized beam is captured. The resin is cured by irradiating the photocurable resin or heating the thermosetting resin. This makes it possible to produce a three-dimensional array structure.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention can be widely used in fields related to nanotechnology, such as production of structures having novel properties.

  1, 2, 1a, 1b, 1c particle, 5 light, 11 substrate, 21, 22 nanomaterial array structure, 100 computer, 101 computer body, 102 bus, 103 FD drive, 104 optical disk drive, 105 communication interface, 106 monitor 107 Keyboard, 108 Mouse, 114 ROM, 120 CPU, 121 Memory, 122 Hard disk, 130 Parameter, 131 Simulation program, 132 Simulation result, 150 Initial condition setting unit, 160 Polarization condition setting unit, 170 Array simulation unit, 200, 220 Manufacturing apparatus, 201 light source, 202 housing, 203 nano material group generation unit, 204 medium supply unit, 205 substrate fixing unit, 206 control unit, 211 laser light source, 212 radius Polarization converter, 213 condensing optical system, 222 grating, 223 telescope, 224 mirror, 225 objective lens, 226 illuminator, 228 video camera, 300 plasmonic solar cell, 302 metal layer, 304 n-type semiconductor layer, 306 p Type semiconductor layer, A, B pattern, Ax axis.

Claims (12)

A method for producing a nanomaterial array structure comprising:
Preparing a nanomaterial population comprising a plurality of nanomaterials;
Irradiating the nanomaterial population with axially symmetric polarized light that is polarized symmetrically with respect to an optical axis, thereby generating a photo-induced force in the plurality of nanomaterials, thereby arranging the plurality of nanomaterials. A method for producing a nanomaterial array structure. The step of arranging the plurality of nanomaterials includes:
The method of manufacturing a nanomaterial array structure according to claim 1, comprising a step of controlling a spot diameter of the axially symmetric polarized light in order to control the photoinduced force.   The method of manufacturing a nanomaterial array structure according to claim 1, further comprising a step of fixing the plurality of nanomaterials arranged by the axially symmetric polarized light.   The method for producing a nanomaterial array structure according to claim 1, wherein the axially symmetric polarized light is radial polarized light.   The method for producing a nanomaterial array structure according to claim 1, wherein the axially symmetric polarized light is azimuth polarized light.   The method for producing a nanomaterial array structure according to claim 1, wherein the nanoparticles are metal nanoparticles. An apparatus for producing a nanomaterial array structure,
A light source that irradiates a group of nanomaterials including a plurality of nanomaterials with axially symmetric polarization that is polarized symmetrically with respect to an optical axis in order to generate a photo-induced force in the plurality of nanomaterials;
An apparatus for manufacturing a nanomaterial array structure, comprising: a control unit that controls the axially symmetric polarized light so that the plurality of nanomaterials are arranged by the photoinduced force.   The said control part is a manufacturing apparatus of the nanomaterial array structure of Claim 7 which controls the spot diameter of the said axially symmetrical polarization | polarized-light in order to control the said light induced force.   The apparatus for manufacturing a nanomaterial array structure according to claim 7, wherein the control unit fixes the plurality of nanomaterials arranged by the axially symmetric polarized light.   The apparatus for producing a nanomaterial array structure according to claim 7, wherein the axially symmetric polarized light is radial polarized light.   The apparatus for producing a nanomaterial array structure according to claim 7, wherein the axially symmetric polarized light is azimuth polarized light.   The apparatus for producing a nanomaterial array structure according to claim 7, wherein the nanoparticles are metal nanoparticles.