JP2007231335A - Fine structure body and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fine structure body which is superior in such energy transferability as to be able to convert light energy to electric energy, and to provide a manufacturing method therefor. <P>SOLUTION: The fine structure body has micropores, in which 50% or more of the micropores are regularly arrayed, and has at least (A) a donor of visible-light absorptive energy and (B) an energy receptor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a microstructure and a manufacturing method thereof.

  In the technical fields of metal and semiconductor thin films, thin wires, dots, etc., the phenomenon of electrical, optical and chemical peculiarities can be seen by confining the movement of free electrons in a size smaller than a certain characteristic length. It has been known. Such a phenomenon is called “quantum mechanical size effect (quantum size effect)”. Research and development of functional materials applying such a unique phenomenon is being actively conducted. Specifically, a material having a structure finer than several hundred nm is referred to as a “microstructure” or “nanostructure”, and is one of the objects of material development.

  As a method for manufacturing such a fine structure, for example, a method for directly manufacturing a nano structure by a semiconductor processing technique including a fine pattern forming technique such as photolithography, electron beam exposure, and X-ray exposure can be given.

In particular, much research has been conducted on methods for producing nanostructures having a regular microstructure.
For example, as a method for forming a regular structure in a self-regulating manner, an aluminum oxide film (anodized film) obtained by subjecting aluminum to an anodizing treatment in an electrolytic solution can be mentioned. It is known that a plurality of fine pores (micropores) having a diameter of about several nm to several hundred nm are regularly formed in the anodized film. By using this self-ordering of the anodized film and obtaining a perfectly regular arrangement, theoretically, hexagonal prism cells with a regular hexagonal bottom centered around the micropores are formed, and adjacent micropores are formed. It is known that the connecting line forms an equilateral triangle.
Non-Patent Document 1 describes an anodized film having micropores. Non-Patent Document 2 describes that pores are spontaneously formed in the anodized film as the oxidation proceeds. Non-Patent Document 3 also proposes forming an Au dot array on a Si substrate using a porous oxide film as a mask.

  The greatest feature of the material of the anodic oxide film is that it adopts a honeycomb structure in which a plurality of micropores are formed in a direction substantially perpendicular to the substrate surface and in parallel at substantially equal intervals. In addition to this, the pore diameter, the pore interval, and the pore depth can be controlled relatively freely, which is a feature not found in other materials (see Non-Patent Document 3).

As an application example of the anodic oxide film, various devices such as an optical functional device, a nano device for supporting a catalyst, a magnetic device, and a light emitter are known. In particular, the optical functional device is a field that has attracted attention in recent years. . For example, Non-Patent Document 4 and the like are researching observation of energy transfer and electron transfer using photosynthesis as a model. The photosynthetic pigment system is a biomolecular material that efficiently absorbs light energy and efficiently transmits excitation energy to the reaction center that converts it into electrical energy. Has a collecting chromoprotein complex. Molecular materials (for example, artificial photosynthesis systems) that chemically mimic these functions are being developed.
The energy transfer as described above has a very high moving speed on the order of picoseconds (10 ⁻¹² ) to nanoseconds (10 ⁻¹⁵ ). Such an energy transfer speed is expressed by Equation 1, and the speed coefficient k is a large variation factor in the distance R between molecules. As a molecular material for controlling the distance between molecules, for example, an LB film (Langmuir-Blodgett film), a method of regularly stacking energy donor molecules and acceptor molecules at a constant distance is known. The LB film has low strength and it is difficult to control the arrangement of molecules, and another device that can control the distance between molecules has been desired.

式中、Ｋは定数、τ_Ｒは蛍光寿命、Ｒは分子間距離、積分部分はエネルギー受容体の吸収ε_Ａ（ｖ）とエネルギー供与体の蛍光スペクトルｆ_Ｄ（ｖ）の重なりを表す。

In the formula, K is a constant, τ _R is the fluorescence lifetime, R is the intermolecular distance, and the integral part represents the overlap of the absorption ε _A (v) of the energy acceptor and the fluorescence spectrum f _D (v) of the energy donor.

H. Masuda et. Al. , Jpn. J. et al. Appl. Phys. , Vol. 37 (1998), pp. L1340-1342, Part 2, No. 1 11A, 1 November 1998 (FIG. 2.) “Surface Technology Handbook”, edited by Surface Technology Association (1998), Nikkan Kogyo Shimbun, p. 490-553 Hideki Masuda, “Highly Ordered Metal Nanohole Array Based on Anodized Alumina”, Solid State Physics, 1996, Vol. 31, No. 5, p. 493-499 S. Akimoto, M .; Yokono, M .; Ohmae, I .; Yamazaki, N .; Nagata, R.A. Tanaka, and M.M. Minuro, Chem. Phys. Lett. , 409, 167 (2005)

  Therefore, the present invention aims to provide a molecular material microstructure that chemically mimics the energy transfer function of a living organism, for example.

  As a result of diligent research, the present inventor has found that an oxide film having micropores with high pore arrangement regularity on the surface carries a light-absorbing energy donor molecule and an energy acceptor molecule, thereby achieving finer energy transferability. The present inventors have found that a structure can be obtained and completed the present invention.

That is, the present invention provides the following (1) to (5).
(1) A microstructure having a micropore with an ordering degree of arrangement of 50% or more, and having at least (A) a visible light-absorbing energy donor, and (B) an energy acceptor.
(2) The microstructure according to the above (1), wherein the visible light absorbing energy donor (A) is a compound having a structure comprising a carotene part, a porphyrin part, and a quinone part.
(3) The microstructure according to (1) or (2) above, wherein the (B) energy acceptor is a compound having a quinone structure.

(4) [1] A step of manufacturing a fine structure having micropores with an ordering degree of arrangement of 50% or more,
[2] (A) Visible light absorbing energy donor or (B) An energy acceptor is attached to the inside of the micropore and the surface of the fine structure, and (A) the visible light absorbing energy donor or ( B) removing only the energy acceptor, and [3] depositing (B) the energy acceptor or (A) the visible light absorbing energy donor on the surface of the micropore,
The manufacturing method of the microstructure in any one of said (1)-(3) which has this.
(5) The step of removing only the (A) visible light-absorbing energy donor or (B) the energy acceptor attached to the surface is a step of polishing at least a part of the micropore. A manufacturing method of a fine structure.

  For example, a microstructure having excellent energy transferability capable of converting light energy into electric energy and a manufacturing method thereof are provided.

The present invention is described in detail below.
1. The fine structure of the present invention is a fine structure having micropores with an ordering degree of arrangement of 50% or more, and has at least (A) a visible light-absorbing energy donor, and (B) an energy acceptor. The micropores with a degree of ordering of 50% or more can arrange energy donor molecules and acceptor molecules at regular distances and regularly, so that, for example, it has excellent energy transfer ability that can convert light energy into electric energy. A fine structure.
When the degree of ordering of the arrangement is preferably 70% or more, more preferably 90% or more, the energy transferability is further improved.

2. Manufacturing method of fine structure

<Board>
The starting material for producing the microstructure of the present invention is a substrate, and the substrate is composed of a surface layer composed of an aluminum member described below and a support provided thereunder. The support and the surface layer may be composed of the same aluminum member, or a relatively low-purity aluminum member may have a high-purity aluminum surface layer.
The support may be a heat-resistant material other than aluminum, and the heat-resistant material is a material having a melting point exceeding the melting point of aluminum (660 ° C.), and the shape thereof is not limited, but the plate-like substrate It is preferable that the material has a melting point of 1000 ° C. or higher. For example, pure metals are Co, Cr, Fe, Cu, Li, Mn, Mo, Nb, Ni, Si, Ta, Ti, W, Zr, and alloys are appropriately mixed and melted as follows. What is known. Examples include cast iron, carbon steel, low alloy steel, stainless steel, Ni steel, Cr—Mo, heat resistant alloys (Inconel, Hastelloy, Nimonic), copper alloys, nickel alloys, and titanium alloys.
Further, some stainless steels include non-magnetic austenitic stainless steel (common name: SUS304) and ferritic stainless steel (magnetized name: SUS405) exhibiting magnetism, martensitic stainless steel, PH steel, Cr cast iron, Cr- It is classified into Ni heat-resistant cast steel and Ni-Cr heat-resistant cast steel.
In addition, inorganic oxide materials such as various ceramics, concrete, bricks, quartz, soda glass, borosilicate glass (trade name: Pyrex ^TM 7740), glass ceramic (trade name: Corning 9606) are also known.

<Aluminum member (aluminum surface layer)>
The aluminum member used in the method for producing a structure of the present invention has an anodic oxide film on one surface where micropores are present. Such an aluminum member can be obtained by anodizing one surface of the aluminum member.
The aluminum member used for the anodizing treatment is not particularly limited, and a conventionally known aluminum member can be used. For example, a pure aluminum plate, an alloy plate containing aluminum as a main component and containing a small amount of foreign elements, a member obtained by depositing high purity aluminum on a low purity aluminum (for example, recycled material), glass, silicon, or the like can be given.
In the aluminum member, the purity of the aluminum part is preferably 99.5% by mass or more, more preferably 99.9% by mass or more, and further preferably 99.99% by mass or more. When the aluminum purity is in the above range, the regularity of the pore arrangement is sufficient.

  The aluminum member is preferably preliminarily degreased and mirror finished. Moreover, when using for the use using the structure of this invention being light transmittance, it is preferable to heat-process beforehand. By heat treatment, a region having a high regularity of pore arrangement is widened.

Hereinafter, the processing procedure of an aluminum member is described in order.
<Heat treatment>
When heat treatment is performed, it is preferably performed at 200 to 350 ° C. for about 30 seconds to 2 minutes. Thereby, the regularity of the arrangement | sequence of the micropore produced | generated by the anodic oxidation process mentioned later improves.
The aluminum member after the heat treatment is preferably cooled rapidly. As a method of cooling, for example, a method of directly feeding into water or the like can be mentioned.

<Degreasing treatment>
Degreasing treatment uses acids, alkalis, organic solvents, etc. to dissolve and remove organic components such as dust, fat, and resin that adhere to the aluminum surface, and causes defects in each treatment described later due to the organic components. This is done for the purpose of preventing the occurrence of.
A conventionally known degreasing agent can be used for the degreasing treatment. Specifically, for example, various commercially available degreasing agents can be used by a predetermined method.

Especially, the following each method is illustrated suitably.
A method in which an organic solvent such as various alcohols (for example, methanol), various ketones, benzine, and volatile oil is brought into contact with the aluminum surface at room temperature (organic solvent method); a solution containing a surfactant such as soap or neutral detergent at room temperature A method of bringing the aluminum surface into contact with the aluminum surface at a temperature of from 80 to 80 ° C., and then washing with water (surfactant method); A method of contacting and then washing with water; a direct current having a current density of 1 to 10 A / dm ² with a sodium hydroxide aqueous solution having a concentration of 5 to 20 g / L being brought into contact with the aluminum surface at room temperature for about 30 seconds, with the aluminum surface serving as a cathode. And then neutralizing by contacting with an aqueous nitric acid solution having a concentration of 100 to 500 g / L; various known anodizing treatment electrodes While in contact with the aluminum surface a liquid at room temperature, the aluminum surface by applying a direct current of a current density of 1 to 10 A / dm ² in the cathode, or a method of electrolysis by passing an alternating current; concentration 10 to 200 g / L A method in which an aqueous alkali solution is brought into contact with an aluminum surface at 40 to 50 ° C. for 15 to 60 seconds, and then neutralized by bringing an aqueous nitric acid solution having a concentration of 100 to 500 g / L into contact; A method in which the mixed emulsion is brought into contact with the aluminum surface at a temperature from room temperature to 50 ° C. and then washed with water (emulsion degreasing method); a mixed solution of sodium carbonate, phosphates, surfactant, etc. The aluminum surface is brought into contact with the aluminum surface for 30 to 180 seconds at a temperature up to and thereafter washed with water (phosphate method).

  The degreasing treatment is preferably a method in which the fat content on the aluminum surface can be removed while aluminum dissolution hardly occurs. In this respect, the organic solvent method, the surfactant method, the emulsion degreasing method, and the phosphate method are preferable.

<Other chemical pretreatment>
Non-Patent Document 6: Aluminum Technical Handbook, Japan Institute of Light Metals, Karos Publishing (1996) Various methods described in chemical pretreatment described in p926-929 can be used, and the factors that cause defects in micropores formed later can be removed. And has the effect of increasing the regularity of the arrangement of micropores. Among them, alkali degreasing, acid degreasing, electrolytic degreasing, or a combination thereof capable of dissolving the surface layer, and alkali etching, acid etching, or a combination thereof having a strong action of dissolving the surface layer can be preferably used. .

<Mirror finish processing>
The mirror finishing process is performed to eliminate unevenness on the surface of the aluminum member and improve the uniformity and reproducibility of the particle forming process by an electrodeposition method or the like. As an unevenness | corrugation of the surface of an aluminum member, the rolling rebar generated at the time of rolling in the case where an aluminum member is manufactured through rolling is mentioned, for example.
In the present invention, the mirror finish is not particularly limited, and a conventionally known method can be used. Examples thereof include mechanical polishing, chemical polishing, and electrolytic polishing.
Examples of the mechanical polishing include a method of polishing with various commercially available polishing cloths, and a method of combining various commercially available abrasives (for example, diamond, alumina) and a buff. Specifically, a method in which the method using an abrasive is performed by changing the abrasive used from coarse particles to fine particles over time is preferably exemplified. In this case, the final polishing agent is preferably # 1500. Thereby, the glossiness can be 50% or more (in the case of rolled aluminum, both the rolling direction and the width direction are 50% or more).

As chemical polishing, for example, “Aluminum Handbook”, 6th edition, edited by Japan Aluminum Association, 2001, p. Various methods described in 164 to 165 may be mentioned.
Further, phosphoric acid - nitric acid method, Alupol I, Alupol V, Alcoa R5, H 3 PO 4 -CH 3 COOH-Cu _{method, H 3 PO 4 -HNO 3 -CH} 3 COOH method are preferable. Among these, the phosphoric acid-nitric acid method, the H ₃ PO ₄ —CH ₃ COOH—Cu method, and the H ₃ PO ₄ —HNO ₃ —CH ₃ COOH method are preferable.
By chemical polishing, the glossiness can be made 70% or more (in the case of rolled aluminum, both the rolling direction and the width direction are 70% or more).

As electrolytic polishing, for example, “Aluminum Handbook”, 6th edition, edited by Japan Aluminum Association, 2001, p. Various methods described in 164 to 165 may be mentioned.
Moreover, the method described in US Pat. No. 2,708,655 is preferable.
“Practical Surface Technology”, vol. 33, no. 3, 1986, p. The method described in 32-38 is also preferably exemplified.
By electropolishing, the gloss can be 70% or more (in the case of rolled aluminum, both the rolling direction and the width direction are 70% or more).

  These methods can be used in appropriate combination. For example, a method of using an abrasive is preferably performed by changing the abrasive to be used from coarse particles to fine particles over time, and then performing electrolytic polishing.

By mirror finishing, for example, a surface having an average surface roughness R _{a of} 0.1 μm or less and a glossiness of 50% or more can be obtained. The average surface roughness _Ra is preferably 0.03 μm or less, and more preferably 0.02 μm or less. Further, the glossiness is preferably 70% or more, and more preferably 80% or more.
The glossiness is a regular reflectance determined in accordance with JIS Z8741-1997 "Method 360 degree specular gloss" in the direction perpendicular to the rolling direction. Specifically, using a variable angle gloss meter (for example, VG-1D, manufactured by Nippon Denshoku Industries Co., Ltd.), when the regular reflectance is 70% or less, the incident reflection angle is 60 degrees and the regular reflectance is 70%. In the case of exceeding, the incident / reflection angle is 20 degrees.

<First anodic oxidation>
In the present invention, it is preferable to form a depression that is a starting point for generating micropores before anodizing treatment (hereinafter also referred to as “second anodizing treatment”) for forming micropores in the aluminum member. . Here, as a method of forming the depression, a first anodizing process using the self-ordering property of the anodized film is used.

The first anodizing treatment in the present invention is a method for improving the regularity by utilizing the property that the micropores of the anodized film are regularly arranged and removing the factors that disturb the regular arrangement. Specifically, high-purity aluminum is used, and an anodized film is formed at a low speed over a long period of time (for example, several hours to several tens of hours) at a voltage corresponding to the type of electrolyte, and then removed. Perform membrane treatment.
In this method, since the pore diameter depends on the voltage, a desired pore diameter can be obtained to some extent by controlling the voltage.

The average flow rate when anodizing is preferably 0.5 to 20.0 m / min. By performing anodizing treatment at a flow rate within this range, uniform and high regularity can be obtained. A more preferable range of the flow rate is 1.0 to 15.0 m / min, and 2.0 to 10.0 m / min is particularly preferable.
In addition, the method of flowing the electrolytic solution under the above conditions is not particularly limited, but for example, a method of using a general stirring device such as a stirrer is used. Furthermore, it is more preferable to use a stirrer that can control the stirring speed by digital display because the average flow rate can be controlled. Examples of such a stirring device include “Magnetic Stirrer HS-50D (manufactured by AS ONE)”.

  For the anodizing treatment used in the present invention, for example, a method of energizing an aluminum member as an anode in a solution having an acid concentration of 1 to 10% by mass can be used. The solution used for the anodizing treatment is preferably an acid solution, more preferably sulfuric acid, phosphoric acid, chromic acid, oxalic acid, sulfamic acid, benzenesulfonic acid, amidosulfonic acid, etc., among which sulfuric acid, phosphoric acid, Oxalic acid is particularly preferred. These acids can be used alone or in combination of two or more.

The conditions for anodizing treatment vary depending on the electrolyte used, and therefore cannot be determined unconditionally. In general, however, the electrolyte concentration is 0.1 to 20% by mass, the solution temperature is -10 to 30 ° C., and the current density. 0.01 to 20 A / dm ² , voltage 3 to 300 V, electrolysis time 0.5 to 30 hours are preferable, electrolyte concentration 0.5 to 15% by mass, liquid temperature −5 to 25 ° C., current density 0 0.05 to 15 A / dm ² , voltage 5 to 250 V, electrolysis time 1 to 25 hours are more preferable, electrolyte concentration 1 to 10% by mass, solution temperature 0 to 20 ° C., current density 0.1 to 10 A / It is particularly preferable that dm ² , voltage is 10 to 200 V, and electrolysis time is 2 to 20 hours.
The film thickness of the anodized film is preferably 1 to 300 μm, more preferably 5 to 150 μm, and particularly preferably 10 to 100 μm.

In the present invention, the first anodizing treatment is preferably 1 to 16 hours, more preferably 2 to 12 hours, and further preferably 2 to 7 hours.
The film removal treatment is preferably 0.5 to 10 hours, more preferably 2 to 10 hours, and further preferably 4 to 10 hours.

<Film removal treatment>
The oxide film formed by the first anodizing treatment is subjected to a film removal treatment for dissolving and removing the anodized film according to the application. That is, the closer the aluminum part is, the higher the regularity is. Therefore, the film is once removed, and the bottom part of the anodic oxide film remaining in the aluminum part is brought out on the surface to obtain regular depressions. Accordingly, in the film removal treatment, aluminum is not particularly dissolved as long as it has a function of dissolving only the anodized film that is aluminum oxide,
(B-1) nitric acid, chromic anhydride, chromium hydroxide,
(B-2) zirconium phosphate compound, titanium phosphate compound,
(B-3) lithium salt compound, cerium salt compound, magnesium salt compound, sodium fluorosilicate,
(B-4) Zinc fluoride, manganese, molybdenum, magnesium, halogen compound,
An aqueous solution having one or a plurality of compounds selected from the group is preferable, and a mixed aqueous solution of phosphoric acid / nitric acid and a mixed aqueous solution of phosphoric acid / chromic anhydride are more preferable.

  The acid concentration contained in these aqueous solutions is preferably 0.01 mol / L to 10 mol / L, more preferably 0.05 mol / L to 5 mol / L, and particularly preferably 0.1 mol / L to 1 mol / L.

  The treatment temperature is 0 ° C. or more, more preferably 20 ° C. or more, particularly preferably 40 ° C. or more, and the treatment time is preferably 30 minutes or more, more preferably 1 hour or more, and particularly preferably 3 hours or more. In addition, since the starting point of ordering will be destroyed and disturb | disturbed if it processes using the boiled aqueous solution, it uses without boiling.

<Second anodizing treatment>
In the present invention, as described above, after forming a depression on the aluminum surface according to the application, an anodized film can be formed by the second anodizing treatment.
For the second anodizing treatment, a conventionally known method can be used, but it is preferable that the second anodizing treatment be performed under the same conditions as the self-ordering method described above.
Also, a method of repeatedly turning on and off the current intermittently while keeping the DC voltage constant, and a method of repeatedly turning on and off the current while intermittently changing the DC voltage can be suitably used. According to these methods, fine micropores are generated in the anodic oxide film, which is preferable in that uniformity is improved particularly when sealing treatment is performed by electrodeposition.
In the above-described method of intermittently changing the voltage, it is preferable to decrease the voltage sequentially. As a result, the resistance of the anodized film can be lowered, and can be made uniform when the electrodeposition treatment is performed later.

The conditions of the anodizing treatment cannot be determined unconditionally because they vary depending on the electrolyte used. In general, the electrolyte concentration is 0.01 to 10 mol / L, the solution temperature is 0 to 20 ° C., and the current density is 0. 0.1 to 10 A / dm ² , voltage 15 to 240 V, electric quantity 3 to 10000 C / dm ² , and electrolysis time 30 to 1000 minutes are preferable.

When the second anodized film is performed at a low temperature (−20 ° C. to −5 ° C.), the arrangement of micropores becomes regular and the pore diameter becomes uniform.
In the present invention, by performing the second anodizing treatment at a relatively high temperature (25 ° C. to 70 ° C.), it is easy to disturb the arrangement of the micropores and make the pore diameter variation within a predetermined range. It becomes. Also, the pore diameter variation can be controlled by the processing time.

The thickness of the second anodic oxide film is preferably at least 10 ² times the pore diameter, more preferably at 10 ⁵ times or more, and particularly preferably 10 ⁷ times or more. For this purpose, the second anodizing treatment is preferably 5 hours or more, more preferably 50 hours or more, and further preferably 300 hours or more.

The average pore density is preferably 50-1500 / μm ² .

The area ratio occupied by the micropores is preferably 20 to 50%.
The area ratio occupied by the micropore is a ratio of the total area of the opening of the micropore to the area of the aluminum surface. In the calculation of the area ratio occupied by the micropores, the micropores include those that are not sealed with metal. Specifically, it is obtained by measuring the surface porosity before the sealing treatment.

<Pore wide processing>
The pore-wide treatment is a treatment for expanding the pore diameter of the micropores by immersing the aluminum member in an acid aqueous solution or an alkali aqueous solution after the second anodizing treatment to dissolve the anodized film.
This makes it easy to control the regularity of the arrangement of micropores and the variation in pore diameter. In addition, by dissolving the barrier film at the bottom of the micropore of the anodized film, it is possible to selectively deposit the inside of the micropore and increase the pore diameter, thereby dramatically increasing the surface area as an electrode. It becomes possible.

When an aqueous acid solution is used for the pore wide treatment, it is preferable to use an aqueous solution of an inorganic acid such as sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, or a mixture thereof. The concentration of the acid aqueous solution is preferably 1 to 10% by mass. The temperature of the acid aqueous solution is preferably 25 to 40 ° C.
When an alkaline aqueous solution is used for the pore-wide treatment, it is preferable to use an aqueous solution of at least one alkali selected from the group consisting of sodium hydroxide, potassium hydroxide and lithium hydroxide. The concentration of the alkaline aqueous solution is preferably 0.1 to 5% by mass. The temperature of the alkaline aqueous solution is preferably 20 to 35 ° C.
Specifically, for example, 50 g / L, 40 ° C. phosphoric acid aqueous solution, 0.5 g / L, 30 ° C. sodium hydroxide aqueous solution or 0.5 g / L, 30 ° C. potassium hydroxide aqueous solution is preferably used. .
The immersion time in the acid aqueous solution or the alkali aqueous solution is preferably 8 to 60 minutes, more preferably 10 to 50 minutes, and further preferably 15 to 30 minutes.

<Measurement of degree of ordering>
Here, the degree of ordering is an index of micropore regularity, and is defined by the following formula (1) by measuring a surface photograph by FE-SEM.
Order degree (%) = B ÷ A × 100 (1)
Here, in the above formula (1), A represents the total number of micropores in the measurement range (1 to 5 μm ² ). B is a micropore that is centered on one micropore and in which the circumference of another micropore closest to the one micropore is inscribed. This represents the number of micropores that will have six (including the micropores whose center is inside the circle).

FIG. 1 is a schematic diagram of the anodized film surface for explaining the degree of ordering of micropores. Hereinafter, B in the above formula (1) will be described in detail with reference to FIG.
As shown in FIG. 1 (a), one micropore 1 is centered on the one micropore 1, and the circumference of another micropore 2 closest to the one micropore 1 is inscribed therein. When the circle 3 is drawn, it becomes a micropore that has six micropores inside the circle 3, and is counted as B. Note that the micropore 4 has a portion protruding from the circle 3, but since the center is inside the circle 3, the micropore 4 is counted as the number of micropores inside the circle 3.
On the other hand, as shown in FIG. 1B, one micropore 5 is centered on the one micropore 5 and the circumference of another micropore 6 that is the closest to the one micropore 5 is When an inscribed circle 7 is drawn, it becomes a micropore that has five micropores inside the circle 7, and therefore cannot be counted as B. Note that the micropores 8 are not counted as the number of micropores inside the circle 7 because the center of the micropores 8 protrudes from the circle 7. Further, when one micropore 9 draws a circle 11 centered on the one micropore 9 and inscribed by the circumference of another micropore 10 at the closest distance to the one micropore 9, Since it is a micropore that has seven micropores inside the circle 11, it cannot be counted as B.

<Micropore>
In the microstructure of the present invention, the degree of order of the arrangement of micropores is 50% or more, preferably 60% or more, more preferably 70% or more, further 80% or more, and 90% or more. When the degree of ordering of the micropore array is 50% or more, the energy conversion efficiency is improved. In the structure of the present invention, the micropores preferably have an average pore diameter of 25 to 35 nm and an average period of 50 to 120 nm. Here, the period means the distance between the centers of adjacent micropores, and the average period is an average value in the measurement visual field.

<(A) Visible Light Absorbing Energy Donor>
The visible light absorptive energy donor of the present invention is not particularly limited as long as it is a compound that can absorb visible light. For example, it is described in Stemberg-Yfrag G, et al Nature (London) 1997; 385: 239-241. A compound having a structure composed of a carotene part, a porphyrin part and a quinone part is preferred, and the following compound [Chemical Formula 1] is particularly preferred. Note that the compound is provided on the microstructure by various known methods such as an application method in which the compound is dissolved in an appropriate solvent and an evaporation method by vapor deposition.

<(B) Energy receptor>
The visible light absorptive energy donor of the present invention is not particularly limited as long as it is a compound that can absorb visible light. For example, it is described in Stemberg-Yfrag G, et al Nature (London) 1997; 385: 239-241. The compound having a quinone structure is preferable, and the following compound [Chemical Formula 2] is particularly preferable. Note that the compound is provided on the microstructure by various known methods such as an application method in which the compound is dissolved in an appropriate solvent and an evaporation method by vapor deposition.

Other examples of the energy acceptor compound used in the present invention are as follows.

<Method of supporting energy donor and energy acceptor on micropore>
(A) A visible light absorbing energy donor and (B) an energy acceptor are supported on a micropore as follows. That is, the preferred method shown in FIG. 3 will be described below.
As shown in FIG. 3A, for example, the aluminum member 12 is anodized as described above and has an anodized film layer having a barrier layer 18 and a micropore 16. (1) The degree of ordering of the array is 50 Producing microstructures with more than% micropores,
(2) (A) As shown in FIG. 3 (b), (A) the visible light-absorbing energy donor 20 is attached to the inside of the micropore and the surface of the microstructure.
Next, as shown in FIG. 3C, (A) only the visible light absorbing energy donor 20 attached to the surface is removed.
(3) As shown in FIG. 3 (d), (B) by attaching the energy acceptor 22 on the surface of the micropore, the energy donor and the energy acceptor are converted into a fine structure at an appropriate intermolecular distance. It can arrange | position and can obtain the microstructure of this invention.
In the above, it is not the (A) visible light absorbing energy donor 20 but the (B) energy acceptor 22 that is first attached to the inside of the micropore and the surface of the fine structure. In FIG. 3 (c), only (B) the energy acceptor 22 attached to the surface is removed, and in FIG. 3 (d), (A) the visible light absorbing energy donor 20 is attached on the surface of the micropore. Thus, the energy donor and the energy acceptor can be arranged in the microstructure with an appropriate intermolecular distance to obtain the microstructure of the present invention.
It is preferable that the size of the molecule to be attached in the first step (1) is smaller than the pore diameter.
The step of removing only (A) visible light absorbing energy donor 20 or (B) energy acceptor 22 attached to the surface shown in FIG. 3C is not limited, but a surface polishing method may be used. Surface polishing using an abrasive such as diamond slurry can be performed.

The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these.
(Examples 1-18, Comparative Example 1)
1. Fabrication of microstructure

  Hereinafter, the substrate and each process will be described.

(1) Production of substrate The substrate used for production of the structure was produced as follows.
Substrate 1: High-purity aluminum, manufactured by Wako Pure Chemical Industries, Ltd., purity 99.99 mass%, thickness 0.4 mm
Substrate 2: Aluminum JIS A1050 material provided with surface layer A, manufactured by Nippon Light Metal Co., Ltd., purity 99.5% by mass, thickness 0.24 mm
Substrate 3: Aluminum JIS A1050 material provided with surface layer B, manufactured by Nippon Light Metal Co., Ltd., purity 99.5% by mass, thickness 0.24 mm
Substrate 4: Aluminum JIS A1050 material, manufactured by Nippon Light Metal Co., Ltd., purity 99.5% by mass, thickness 0.30 mm
Substrate 5: Aluminum JIS A1050 material provided with surface layer C, manufactured by Nippon Light Metal Co., Ltd., purity 99.5% by mass, thickness 0.30 mm
Substrate 6: Aluminum JIS A1050 material provided with surface layer D, manufactured by Nippon Light Metal Co., Ltd., purity 99.5% by mass, thickness 0.30 mm

Substrate 7: Aluminum vapor-deposited film, Trefan AT80, manufactured by Toray Industries, Inc., purity 99.9% by mass, thickness 0.02 mm
Substrate 8: Aluminum XL untreated material provided with surface layer A, manufactured by Sumitomo Light Metal Industries, Ltd., purity 99.3 mass%, thickness 0.30 mm
Substrate 9: Glass provided with surface layer E, manufactured by AS ONE, purity 99.9% by mass, thickness 5 mm
Substrate 10: Silicon wafer provided with surface layer E, manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99% by mass or more Substrate 11: Synthetic quartz provided with surface layer E, VIOSIL-SG-2B, manufactured by Shin-Etsu Chemical Co., Ltd., purity 99.99 mass% or more, thickness 0.6mm
Substrate 12: A copper-clad laminate (RAS33S42, manufactured by Shin-Etsu Chemical Co., Ltd., purity unknown, thickness 0.08 mm) with a surface layer E provided with an Al—Cu alloy film by sputtering.

The aluminum JIS A1050 material has a regular reflectance of 40% in the vertical direction (standard deviation of 10%), a regular reflectance of 15% in the lateral direction (standard deviation of 10%), and a purity of 99.5% by mass (standard deviation of 0.1%). 1% by mass).
Further, the above-mentioned aluminum XL non-treated material has a vertical regular reflectance of 85% (standard deviation of 5%), a horizontal regular reflectance of 83% (standard deviation of 5%), and a purity of 99.3% by mass (standard deviation of 0). .1% by mass).

Further, the surface layers A to E were produced as follows.
Surface layer A is a vacuum vapor deposition method, ultimate pressure: 4 × 10 ⁻⁶ Pa, vapor deposition current: 40 A, substrate: 150 ° C. heating, vapor deposition material: conditions of aluminum wire with purity 99.9% by mass (manufactured by Niraco) And formed on the substrate. The thickness of the surface layer A was 0.2 μm.
The surface layer B was formed by the same method as the surface layer A, except that an aluminum wire having a purity of 99.99% by mass (manufactured by Niraco) was used as the vapor deposition material. The thickness of the surface layer B was 0.2 μm.
Surface layer C is formed by sputtering, ultimate pressure: 4 × 10 ⁻⁶ Pa, sputtering pressure: 10 ⁻² Pa, argon flow rate: 20 sccm, substrate: 150 ° C. control (with cooling), bias: none, sputtering power source: RC Sputtering power: RF 400 W, sputtering material: 3N backing plate (manufactured by Kyodo International Co., Ltd.) having a purity of 99.9% by mass. The thickness of the surface layer C was 0.5 μm.
The surface layer D was formed by the same method as the surface layer A except that a 4N backing plate (manufactured by Kyodo International Co., Ltd.) having a purity of 99.99% by mass was used as the sputtering material. The thickness of the surface layer D was 0.5 μm.
The surface layer E was formed by the same method as the surface layer A, except that the thickness was 1 μm.

The thickness of the surface layer is determined by masking the PET substrate, performing the vacuum deposition method and the sputtering method while changing the time under the same conditions as described above, and using an atomic force microscope (AFM). It adjusted by adjusting time using the correlation calibration curve of the time and film thickness obtained by measuring each film thickness.
In addition, the purity of the surface layer was determined using a scanning X-ray photoelectron spectrometer (Quantum 2000, manufactured by ULVAC-PHI) to perform a full quantitative analysis while digging in the depth direction with an ion gun for etching. The content of was quantified by a calibration curve method. As a result, all the surface layers had substantially the same purity as the vapor deposition material or the sputtering material.

(2) Mirror surface finishing process About the board | substrates 1-6 among the said substrates 1-12, the following mirror surface finishing processes were performed.
<Mirror finish processing>
By performing polishing using a polishing cloth, buffing and electrolytic polishing in this order, a mirror finish was applied. After buffing, it was washed with water.
Polishing using a polishing cloth uses a polishing disk (Struers Abramin, manufactured by Marumoto Kogyo Co., Ltd.) and a water-resistant polishing cloth (commercially available), and the number of the water-resistant polishing cloth is # 200, # 500, # 800, # 1000 and # The change was made in the order of 1500.
The buffing was performed using a slurry-like abrasive (FM No. 3 (average particle size 1 μm) and FM No. 4 (average particle size 0.3 μm), both manufactured by Fujimi Incorporated).
The electrolytic polishing was performed for 2 minutes using an electrolytic solution (temperature: 70 ° C.) having the following composition, using the anode as a substrate and the cathode as a carbon electrode at a constant current of 130 mA / cm ² . As a power source, GP0110-30R (manufactured by Takasago Seisakusho) was used.

<Electrolyte composition>
-660 mL of 85% by mass phosphoric acid (reagent manufactured by Wako Pure Chemical Industries, Ltd.)
・ Pure water 160mL
・ Sulfuric acid 150mL
・ Ethylene glycol 30mL

(3) 1st anodic oxidation The hollow used as the starting point of micropore formation was formed in the surface of the board | substrates 1-6 which performed mirror surface finishing, and the board | substrates 7-12 which did not perform mirror surface finishing with the following method.

  The self-ordered anodizing treatment was carried out at the kind, concentration, electrolyte flow rate, temperature, voltage, current density and treatment time shown in Table 1 to form an anodized film. In the self-ordering anodizing treatment, NeoCool BD36 (manufactured by Yamato Scientific Co., Ltd.) is used as a cooling device, Pear Stirrer PS-100 (manufactured by EYELA) is used as a stirring and heating device, and GP0650-2R (manufactured by Takasago Seisakusho) is used as a power source. It was. The flow rate of the electrolyte was measured using a vortex flow monitor FLM22-10PCW (manufactured by AS ONE).

  In Table 1, for phosphoric acid, oxalic acid, and sulfuric acid, all reagents manufactured by Kanto Chemical Co., Ltd. were used. The current density showed a stable value.

After the first anodic oxidation treatment, an immersion treatment was performed under the conditions shown in Table 2 in order to remove the oxide film.

  In Table 2, for 85% by mass phosphoric acid and chromic anhydride, reagents manufactured by Kanto Chemical Co., Inc. were used. In addition, the process liquid used for conditions 53 and 56 is a composition prescribed | regulated to JISH8688 (1998) -H8688.

(4) Second anodizing treatment The substrate on which the depressions were formed was subjected to a second anodizing treatment. The second anodizing treatment is performed by performing self-ordering anodizing treatment with the kind, concentration, flow rate, temperature, voltage, current density and treatment time of the electrolyte shown in Table 3 and shown in Table 6. An anodic oxide film having a film thickness was formed. In the self-ordering anodizing treatment, NeoCool BD36 (manufactured by Yamato Scientific Co., Ltd.) is used as a cooling device, Pear Stirrer PS-100 (manufactured by EYELA) is used as a stirring and heating device, and GP0650-2R (manufactured by Takasago Seisakusho) is used as a power source. It was.

(5) Pore-wide treatment The pore-wide treatment was performed by immersing the substrate in a treatment solution of the type, concentration and temperature shown in Table 4 for the time shown in Table 5.

  As shown in the table below, each support was obtained by subjecting the substrate to a mirror finishing process, a first anodizing process, a second anodizing process, a pore wide process, and an aluminum member removing process in this order. In Table 5, “-” indicates that the corresponding processing is not performed.

2. Attachment of Energy Receptor On the fine structures of Examples 1 to 18 and Comparative Example 1 obtained by the procedure described above, a quinone compound having the structure described in the above [Chemical Formula 2] was attached by vapor deposition. Then, only the surface part was grind | polished using the diamond slurry as an abrasive | polishing agent, and the water washing / drying process was performed. When the surface part was observed by FE-SEM, it was confirmed that in Examples 1 to 18, only the inside of the pore was filled with the quinone compound.

3. Attachment of Visible Light Absorbing Energy Donor On the microstructures of Examples 1 to 18 and Comparative Example 1 obtained by the above-described procedure, a carotene-porphyrin-quinone compound having the structure described in [Chemical Formula 1] is deposited. Attached. When the surface part was observed by FE-SEM, it was confirmed that the carotene-porphyrin-quinone compound was attached to the micropore surface with a thickness of 100 nm.

4). Properties of Structure In order to confirm the energy transfer rate of the structure obtained above, the fluorescence lifetime was measured from an absorption spectrum, a time-resolved fluorescence spectrum, and a fluorescence decay curve.

In order to measure the absorption spectrum, a 5 × 10 ⁻⁶ mol / L cyclohexane solution of the energy donor compound was prepared, and the absorption spectrum was measured using a Ubest-50 type spectrophotometer (manufactured by JASCO Corporation). .

The time-resolved fluorescence spectrum and fluorescence decay curve were measured as follows. That is, as shown in FIG. 2, the second harmonic of the emission line wavelength of the tunable solid-state laser Ti-sapphire laser 52 (COHERENT MIRA900) is matched with the vicinity of the peak wavelength of the absorption spectrum previously obtained to obtain excitation light. It was. Fluorescent pulses from Examples 1 to 18 and Comparative Example 1 obtained by this excitation light were spectrally separated by passing through a monochromator 82 (Nikon P250), and a microchannel plate type photomultiplier tube 83 (MCP-PMT: Hamamatsu Photonics R2809U-01). However, since this fluorescence pulse wave includes a noise pulse, the noise pulse is removed by passing through a low ratio type timing wave height discriminator 85 (CDE: ORTFC), and then the time voltage converter 64 (TAC: Tennerec) is used as a start pulse 87. TC86). The start pulse starts charging the capacitor in the TAC.
On the other hand, the light dispersed by the dichroic mirror was received by the PIN photodiode 61, discriminated by the CFD 62, and sent to the TAC 64 as a stop pulse 67. The charging of the TAC 64 is stopped by the stop pulse 67, and a pulse proportional to the voltage generated between the capacitors, that is, proportional to the time between the start pulse 87 and the stop pulse 67 is output. The output pulse of the TAC 64 is converted into a digital quantity by an analog-digital converter and sent to a multichannel wave height analyzer 65 (MCPHA: Camberra series 35). This MCPHA is accumulated one count at the address converted to the digital quantity, and the histogram becomes a fluorescence decay curve. The time when the intensity of the fluorescence decay curve was 1 / e was defined as the fluorescence lifetime. The results are shown in Table 6. This measurement method is called a so-called single photon measurement method in which the emission probability distribution of one photon by one excitation event becomes an actual distribution on the time axis of all photons emitted by excitation. The laser system is shown in FIG.

  Further, the degree of ordering of pores of the fine structure was measured from a surface photograph by FE-SEM. About 200 to 400 micropores were measured by the method shown in FIG. 1, and the results are shown in Table 6 as an average value of n = 10.

  As is clear from Table 6, in Examples 1 to 18 in which the pores are regularly arranged on the substrate, the fluorescence lifetime can be measured, and energy transfer occurs on the order of several tens of picoseconds. Was observed. On the other hand, in Comparative Example 1, the energy transfer was not uniform, and the fluorescence lifetime could not be measured.

FIG. 1 is a schematic view of the anodized film surface for explaining the degree of ordering of micropores. FIG. 2 is a schematic diagram for explaining the single photon measurement method. FIG. 3 is a schematic diagram for explaining a method for supporting an energy donor and an energy acceptor on a micropore.

Explanation of symbols

1, 5, 9 One micropore 2, 6, 10 Other micropore 3, 7, 11 Circle 4, 8, 16 Micropore 12 Support (aluminum member)
14 Anodized film layer 18 Barrier layer 20 Visible light absorbing energy donor 22 Energy acceptor 51 Ar-ion laser 52 Ti-sapphire laser 53 Pulse picker 54 LBO harmonic control device 55 BBO harmonic control device 61 PIN photodiode 62 Low Ratio type timing wave height discriminator 63 Delay generator 64 Time voltage converter 65 Multi-channel wave height analyzer 66 Computer 67 Stop pulse 71 Vacuum pump 72 Heater 73 Cryostat 74 Fine structure 75 Lens / Shutter 81 Spectrometer (Depolarizer)
82 Monochromator 83 Microchannel plate type photomultiplier tube 84 Amplifier 85 Low ratio type timing wave height discriminator 87 Start pulse

Claims (5)

A microstructure having a micropore having an ordering degree of arrangement of 50% or more, wherein the microstructure has at least (A) a visible light-absorbing energy donor, and (B) an energy acceptor.   The microstructure according to claim 1, wherein the (A) visible light-absorbing energy donor is a compound having a structure comprising a carotene part, a porphyrin part, and a quinone part.   The fine structure according to claim 1 or 2, wherein the (B) energy acceptor is a compound having a quinone structure. (1) a step of manufacturing a fine structure having micropores with an ordering degree of arrangement of 50% or more;
(2) (A) a visible light absorbing energy donor or (B) an energy acceptor is attached to the inside of the micropore and the surface of the fine structure, and (A) the visible light absorbing energy donor or ( B) removing only the energy acceptor, and (3) attaching (B) the energy acceptor or (A) the visible light absorbing energy donor on the surface of the micropore,
The manufacturing method of the microstructure in any one of Claims 1-3 which has these.   5. The microstructure according to claim 4, wherein the step of removing only (A) the visible light-absorbing energy donor or (B) the energy acceptor attached to the surface is a step of polishing at least a part of the micropore. Production method.

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