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WO2010143225A1 - Luminescent powder, method for producing same, luminescent element wherein luminescent powder is used, method for producing said luminescent element, and apparatus for producing luminescent powder - Google Patents

Luminescent powder, method for producing same, luminescent element wherein luminescent powder is used, method for producing said luminescent element, and apparatus for producing luminescent powder Download PDF

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Publication number
WO2010143225A1
WO2010143225A1 PCT/JP2009/002596 JP2009002596W WO2010143225A1 WO 2010143225 A1 WO2010143225 A1 WO 2010143225A1 JP 2009002596 W JP2009002596 W JP 2009002596W WO 2010143225 A1 WO2010143225 A1 WO 2010143225A1
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WO
WIPO (PCT)
Prior art keywords
supercritical fluid
light emitting
luminescent powder
crystal silicon
single crystal
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PCT/JP2009/002596
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French (fr)
Japanese (ja)
Inventor
齋藤健一
山村知玄
Original Assignee
国立大学法人広島大学
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Priority to PCT/JP2009/002596 priority Critical patent/WO2010143225A1/en
Publication of WO2010143225A1 publication Critical patent/WO2010143225A1/en

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/59—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing silicon
    • C09K11/592—Chalcogenides
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/02—Elements
    • C30B29/06—Silicon
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B33/00—After-treatment of single crystals or homogeneous polycrystalline material with defined structure
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/10—Apparatus or processes specially adapted to the manufacture of electroluminescent light sources
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/12—Light sources with substantially two-dimensional radiating surfaces
    • H05B33/14—Light sources with substantially two-dimensional radiating surfaces characterised by the chemical or physical composition or the arrangement of the electroluminescent material, or by the simultaneous addition of the electroluminescent material in or onto the light source

Definitions

  • the present invention relates to a luminescent powder, a manufacturing method thereof, a light emitting element using the luminescent powder, a manufacturing method of the light emitting element, and a manufacturing apparatus of the luminescent powder.
  • Each of the light emitting layers A, B, and C is made of silicon oxide and nanosilicon contained in the silicon oxide.
  • the nanosilicon contained in the light emitting layers A, B, and C has different sizes. More specifically, the nanosilicon included in the light emitting layer A has a size of 1.5 to 2.0 nm, and the nanosilicon included in the light emitting layer B has a size of 2.0 to 2.5 nm.
  • the nanosilicon contained in the light emitting layer C has a size of 2.5 to 3.5 nm.
  • the silicon oxide film is manufactured by a high frequency sputtering method and a heat treatment. More specifically, the silicon oxide film includes an amorphous silicon oxide film a that is the source of the light emitting layer A, an amorphous silicon oxide film b that is the source of the light emitting layer B, and an amorphous silicon oxide film c that is the source of the light emitting layer C.
  • the silicon oxide film includes an amorphous silicon oxide film a that is the source of the light emitting layer A, an amorphous silicon oxide film b that is the source of the light emitting layer B, and an amorphous silicon oxide film c that is the source of the light emitting layer C.
  • the silicon oxide film is formed by sequentially laminating the amorphous silicon oxide films a, b, and c having different amounts of silicon atoms, and the light-emitting layers A and B containing nano-silicones having different sizes by heat-treating the laminated bodies. , C is manufactured.
  • Another object of the present invention is to provide a method for producing a luminescent powder capable of emitting white light.
  • Another object of the present invention is to provide an apparatus for producing a luminescent powder capable of emitting white light.
  • the luminescent powder includes a first step of holding single crystal silicon in a supercritical fluid made of carbon dioxide, and laser ablation in which nano-sized crystal silicon jumps out of the single crystal silicon into the supercritical fluid.
  • a method for producing a luminescent powder includes a first step of holding single crystal silicon in a supercritical fluid made of carbon dioxide, and a nanosize crystalline silicon from single crystal silicon to a supercritical fluid. A second step of irradiating the single crystal silicon with a laser beam having an intensity that causes laser ablation to jump out.
  • At least one of the first and second electrodes is composed of a plurality of electrode pieces.
  • the method for manufacturing a light emitting element includes a first step of manufacturing a plurality of light emitting powders, and a light emitting member made of a plurality of light emitting powders by collecting the plurality of light emitting powders.
  • the first step includes a first sub-step of holding single crystal silicon in a supercritical fluid made of carbon dioxide, and laser ablation in which nano-sized crystal silicon jumps out of the single crystal silicon into the supercritical fluid.
  • the luminescent powder can emit white light.
  • FIG. 1 It is sectional drawing of the luminescent powder by embodiment of this invention. It is the schematic which shows the structure of the manufacturing apparatus of the luminescent powder by embodiment of this invention. It is process drawing which shows the manufacturing method of the luminescent powder shown in FIG. It is a schematic diagram of the luminescent powder deposited on the substrate. It is an optical microscope image of the several luminescent powder arrange
  • FIG. Fig. 4 It is another fluorescence microscope image of the luminescent powder manufactured according to the process shown in FIG. Fig. 4 is a photoluminescence spectrum of a luminescent powder produced according to the process shown in Fig. 3. It is a figure which shows the pressure dependence of the integrated intensity
  • FIG. 1 is a cross-sectional view of a luminescent powder according to an embodiment of the present invention.
  • luminescent powder 10 according to an embodiment of the present invention includes crystalline silicon 1 and silicon oxide 2.
  • the silicon oxide 2 covers the crystalline silicon 1. Therefore, the luminescent powder 10 has a core / shell structure with the crystalline silicon 1 as a core.
  • the crystalline silicon 1 is made of single crystal silicon and has a spherical shape.
  • the crystalline silicon 1 has an average particle diameter of about 2 nm.
  • the silicon oxide 2 is made of silicon dioxide (SiO 2 ) and has an average thickness of about 2 nm. Therefore, the luminescent powder 10 has a spherical shape having a diameter of about 6 nm.
  • FIG. 2 is a schematic diagram showing a configuration of a luminescent powder manufacturing apparatus according to an embodiment of the present invention.
  • the luminescent powder manufacturing apparatus 100 includes a cylinder 20, pipes 21 and 23, a pump 22, a cooler 24, a reaction vessel 25, a laser device 26, a lens 27, and a heater. 28, a thermocouple 29, a temperature detector 30, and a controller 31.
  • the cylinder 20 has a pressure valve 201 and is a siphon type CO 2 cylinder.
  • the cylinder 20 stores gaseous carbon dioxide (CO 2 ).
  • the pipe 21 is an oil-free pipe and supplies CO 2 stored in the cylinder 20 to the pump 22 via the pressure valve 201.
  • the pressure valve 201 is sealed with a CO 2 swelling-resistant material (for example, ethylene propylene rubber, nitrile rubber, and chloropyrene rubber).
  • the pump 22 is manufactured by removing the lubricant. Then, the pump 22 supplies CO 2 supplied from the cylinder 20 via the pipe 21 into the reaction vessel 25 via the pipe 23. In this case, the pump 22 supplies a supercritical fluid composed of CO 2 via the CO 2 piping 23 so that the pressure generated in the reaction vessel 25 within the reaction vessel 25.
  • the lens 27 condenses the laser light emitted from the laser device 26 and irradiates the silicon lump 40 with the condensed laser light through the sapphire window 252. In this case, the lens 27 condenses the laser light so that the energy per pulse is changed from 19 mJ / pulse to 800 mJ / pulse.
  • the silicon lump 40 is made of, for example, a cube having a side length of 1 cm and has a (111) plane orientation.
  • the substrate 50 is made of, for example, carbon (C) or stainless steel. And the board
  • the heater 28 heats the reaction vessel 25 to a temperature at which CO 2 in the reaction vessel 25 becomes a supercritical fluid in accordance with control from the controller 31.
  • the thermocouple 29 detects an electromotive force due to the temperature of CO 2 in the reaction vessel 25 and outputs the detected electromotive force to the temperature detector 30.
  • the temperature detector 30 receives an electromotive force from the thermocouple 29, and detects the temperature T of CO 2 based on the received electromotive force. Then, the temperature detector 30 outputs the detected temperature T to the controller 31.
  • a high-pressure valve is also used in the path for supplying CO 2 from the cylinder 20 to the reaction vessel 25.
  • the high-pressure valve (diaphragm type) is connected to the oil-free valve. Become.
  • the pump 22 supplies CO 2 into the reaction vessel 25 so that the pressure in the reaction vessel 25 is in the range of 4.56 MPa to 14.8 MPa.
  • the heater 28 heats the reaction container 25 so that the temperature T of CO 2 in the reaction container 25 is in the range of 40 ° C. to 50 ° C.
  • the pressure in the reaction vessel 25 is in the range of 4.56 MPa to 14.8 MPa, and the temperature T of CO 2 in the reaction vessel 25 is not less than the critical temperature of 31 ° C., for example, in the range of 40 ° C. to 50 ° C. If it becomes, the CO 2 in the reaction vessel 25 becomes a supercritical fluid.
  • the gaseous CO 2 output from the pump 22 is cooled by the cooler 24 so as to become liquid CO 2.
  • liquid CO 2 is more gaseous CO 2.
  • the pressure of CO 2 in the reaction vessel 25 is easily set to a pressure of 4.56 MPa to 14.8 MPa by the pump 22 because it is easier to pressurize by the pump 22 than 2 . That is, it is for stably producing a supercritical fluid composed of CO 2 .
  • the pressure valve 201 supplies gaseous CO 2 from the cylinder 20 to the pump 22 via the pipe 21, and the pump 22 outputs CO 2 into the pipe 23.
  • the cooler 24 cools gaseous CO 2 to liquid CO 2 .
  • the pump 22 supplies the cooled liquid CO 2 to the reaction vessel 25 so as to have a pressure at which a supercritical fluid is generated in the reaction vessel 25 (step S2).
  • thermocouple 29 detects an electromotive force due to the temperature of CO 2 in the reaction vessel 25 and outputs the detected electromotive force to the temperature detector 30.
  • the temperature detector 30 detects the temperature T of CO 2 in the reaction vessel 25 based on the electromotive force received from the thermocouple 29 and outputs the detected temperature T to the controller 31.
  • the laser device 26 stops the laser beam irradiation (step S5).
  • nano products are grown in the reaction vessel 25 for the growth time determined by the pressure in the reaction vessel 25 (step S6). Due to this growth, crystalline silicon that has jumped into the supercritical fluid is cooled by supercritical CO 2 at the nanosecond to picosecond term scale immediately after laser light irradiation, and emits light while moving downward in the supercritical fluid. The luminescent powder 10 is deposited on the substrate 50. During these periods, the reaction vessel 25 is controlled by the controller 31 so as to have the same temperature.
  • the growth time is 4 to 10 minutes when the pressure in the reaction vessel 25 is 4.56 MPa, and 1 hour when the pressure in the reaction vessel 25 is 11.0 MPa. When the internal pressure is 14.8 MPa, it is 2 hours. These times were determined based on the calculated time for 100 nm particles to sink by 1 cm.
  • the growth time determined by the pressure of the supercritical fluid is generated by the CO 2 in the reaction vessel 25 and the laser ablation.
  • the crystalline silicon is cooled and the luminescent powder 10 is deposited on the substrate 50.
  • the laser device 26 condenses the laser light by the lens 27 and irradiates the silicon lump 40 with the laser light having an intensity of 800 mJ / pulse.
  • the laser device 26 is not limited to this, and the laser device 26 uses laser light having an intensity of 200 mJ / pulse or more, which is a critical intensity at which laser ablation occurs in which nano-sized crystalline silicon jumps out of the silicon mass 40 into the supercritical fluid. What is necessary is just to irradiate the silicon lump 40 via 27.
  • a plurality of luminescent powders 10 forming a network structure were collected and analyzed by EPMA (Electron Probe Micro Analyzer).
  • FIG. 6 is a diagram showing an analysis result by small-angle X-ray scattering. X-ray small angle scattering was measured using CuK ⁇ rays having a wavelength of 1.5 mm.
  • Curve k1 shows the analysis result by X-ray small angle scattering of the luminescent powder 10 manufactured by setting the pressure of the supercritical fluid made of CO 2 to 4.56 MPa. Furthermore, a curve k2 shows the analysis result by X-ray small angle scattering of the luminescent powder 10 manufactured by setting the pressure of the supercritical fluid made of CO 2 to 10.4 MPa. Furthermore, the curve k3 shows a typical spectrum of X-ray small angle scattering.
  • the luminescent powder 10 was composed of Si having a diameter of about 2 nm and SiO 2 having a thickness of about 2 nm. .
  • the luminescent powder 10 emits white light blue as a whole and emits white light in the region indicated by the arrow A.
  • FIG. 9 is another optical microscope image of a plurality of luminescent powders arranged on a stainless steel substrate.
  • the optical microscope image was taken under the same shooting conditions as those of the optical microscope image shown in FIG. Referring to FIG. 9, a product composed of a plurality of luminescent powders 10 is generated. And a product has a projection part.
  • FIG. 10 is another fluorescence microscopic image of the luminescent powder 10 manufactured according to the process shown in FIG.
  • the excitation wavelength of the luminescent powder 10 when a fluorescent microscope image is taken is 325 nm, and the intensity of the excitation light is 20 mW.
  • the fluorescence microscope image was image
  • FIG. 11 is a photoluminescence spectrum of the luminescent powder 10 produced according to the process shown in FIG. In FIG. 11, the horizontal axis represents wavelength (or energy), and the vertical axis represents intensity.
  • the excitation wavelength of the luminescent powder 10 when measuring photoluminescence is 325 nm, and the intensity of the excitation light is 2 mW.
  • a laser beam having a wavelength of 325 nm is irradiated onto the sample by epi-illumination (the intensity of the excitation light immediately before the sample is several tens of ⁇ W), and light emitted from the sample is collected by an ultraviolet-compatible objective lens.
  • the wavelength was dispersed by a single-type spectrometer, and the spectrum was measured by a CCD camera.
  • an instrument function is obtained based on an intensity-corrected light source compliant with the National Institute of Standards and Technology (NIST), and the spectral sensitivity characteristic is calibrated using the device function. The measurement was performed at normal temperature and normal pressure.
  • FIG. 12 is a diagram showing the pressure dependence of the integrated intensity of the emission spectrum.
  • the horizontal axis represents the pressure of the supercritical fluid at the time of manufacturing the luminescent powder 10
  • the vertical axis represents the integrated intensity.
  • Curve k9 shows the pressure dependence of the integrated intensity of the emission spectrum 40 minutes after producing the luminescent powder 10
  • curve k10 shows the emission spectrum two days after producing the luminescent powder 10.
  • the pressure dependence of the integrated intensity is shown
  • the curve k11 shows the pressure dependence of the integrated intensity of the emission spectrum two months after the luminescent powder 10 is manufactured.
  • the integrated intensity of the emission spectrum after 40 minutes from the production of the luminescent powder 10 is substantially constant with respect to the pressure of the supercritical fluid (see curve k9).
  • the luminous powder 10 after two months from the production of the luminous powder 10 has a maximum luminous intensity (integrated intensity) of about 100 times (see curves k9 and k11).
  • the emission intensity can be controlled by controlling the pressure of the supercritical fluid when the luminescent powder 10 is manufactured.
  • the emission intensity (integrated intensity) of the luminescent powder 10 becomes stronger as the elapsed time after the luminescent powder 10 is manufactured becomes longer (see curves k9 to k11).
  • steps S1 to S3 constitute a “first process” for holding single crystal silicon in a supercritical fluid made of carbon dioxide.
  • step S4 by irradiating the silicon lump 40 made of single crystal silicon with laser light having an intensity that causes laser ablation, the nano-sized crystalline silicon jumps out of the silicon lump 40 into the supercritical fluid.
  • Step S4 constitutes a “second step” of irradiating the single crystal silicon with a laser beam having an intensity that causes laser ablation in which nano-sized crystal silicon jumps out of the single crystal silicon into the supercritical fluid.
  • the crystalline silicon jumps out of the silicon lump 40 into the supercritical fluid by laser ablation, and the luminescent powder 10 is manufactured if the jumped crystalline silicon is cooled for an arbitrary time. Even if the sample is taken out before the time elapses, the luminescent powder 10 can be obtained. Therefore, the luminescent powder according to the embodiment of the present invention only needs to be manufactured by the first and second steps described above.
  • FIG. 13 is a cross-sectional view showing the configuration of the light emitting device according to the embodiment of the present invention.
  • a light emitting device 200 according to an embodiment of the present invention includes a transparent substrate 210, a transparent conductive film 220, a conductive polymer 230, a light emitting member 240, and an electrode 250.
  • the transparent substrate 210 is made of a film or glass.
  • the transparent conductive film 220 is made of any material for flexible displays such as ITO (Indium Tin Oxide), SnO 2 , ZnO, and organic EL (Electro Luminescence), and is formed around the transparent substrate 210.
  • the conductive polymer 230 is made of any one of polyacetylene, polyparaphenylene, polyaniline, polythiophene, and polyparaphenylene vinylene.
  • the conductive polymer 230 is disposed between the transparent conductive film 220 and the light emitting member 240 in contact with the transparent conductive film 220 and the light emitting member 240.
  • the light emitting member 240 is composed of a plurality of laminated light emitting powders 10.
  • the light emitting member 240 is disposed between the conductive polymer 230 and the electrode 250 in contact with the conductive polymer 230 and the electrode 250.
  • the light emitting element 200 emits white light when a voltage of 3.82 V is applied between the transparent conductive film 220 and the electrode 250, and a voltage of 3.3 V is generated between the transparent conductive film 220 and the electrode 250.
  • a voltage of 3.82 V is applied between the transparent conductive film 220 and the electrode 250
  • a voltage of 3.3 V is generated between the transparent conductive film 220 and the electrode 250.
  • FIG. 14 is a process diagram showing a method of manufacturing the light emitting device 200 shown in FIG. Referring to FIG. 14, when the manufacture of light emitting element 200 is started, a plurality of light emitting powders 10 are manufactured according to the process shown in FIG. 3 (step S11).
  • step S12 a plurality of luminescent powders 10 are collected and a light emitting member 240 made of the plurality of luminescent powders 10 is manufactured.
  • the light emitting member 240 is bonded to the transparent conductive film 220 by the conductive polymer 230 (step S13).
  • the electrode 250 is formed on the light emitting member 240 by any of sputtering, vapor deposition, and ink jet method (step S14). Thereby, the light emitting element 200 is completed.
  • FIG. 15 is a cross-sectional view showing the configuration of another light emitting device according to the embodiment of the present invention.
  • the light emitting device according to the embodiment of the present invention may be a light emitting device 200A shown in FIG.
  • the region of the light emitting member 240 in contact with the electrode piece 261 emits white light
  • the region of the light emitting member 240 in contact with the electrode piece 262 emits blue light
  • the region of the light emitting member 240 in contact with the electrode piece 263 is green.
  • the region of the light emitting member 240 that emits light and contacts the electrode piece 264 emits red light.
  • the light emitting element 200A is manufactured according to a process of adding a step of patterning the electrode 260 into electrode pieces 261 to 264 by photolithography after step S14 shown in FIG.
  • the electrode 250 may be made of a transparent conductive film such as ITO.
  • the light emitting element 200A may include an n-type or p-type silicon wafer having a carrier concentration of 10 20 cm ⁇ 3 or more, instead of the transparent substrate 210 and the transparent conductive film 220. In this case, the emitted light is emitted in the lateral direction of the light emitting element 200A.
  • the transparent conductive film 220 may be patterned in the same manner as the electrode 260.
  • at least one of the two electrodes disposed on both sides of the light emitting member 240 may be patterned into a plurality of electrode pieces.
  • the light emitting elements 200 and 200A described above are applied to lighting devices and display devices.
  • the luminescence lifetime of silicon nanomaterials is assumed to be on the order of microseconds (in some cases on the order of nanoseconds or picoseconds), considering its size. Therefore, by using the switching circuit, the light emission / flashing becomes quick and the electric follow-up property is good. As a result, the light emitting elements 200 and 200A are more suitable for a moving image display than a liquid crystal display device.
  • the luminescent powder 10 can be applied to an element for photoluminescence (PL).
  • PL photoluminescence
  • the conventional fluorescent lamp mercury is enclosed, and rare earth elements such as eurobium (Eu) and terbium (Tb) are excited by ultraviolet light of the enclosed mercury, and light of three primary colors is mixed to form a white fluorescent lamp. Therefore, when the above-described luminescent powder 10 is used in a fluorescent lamp, it can be used as a substitute for rare earth elements and a white fluorescent lamp can be realized by ultraviolet irradiation.
  • the luminescent powder 10 can also be applied to a plasma display.
  • the luminescent powder 10 is mixed with the ultraviolet transmissive polymer by mixing the luminescent powder 10 with the ultraviolet transmissive polymer together with the solvent, coating the solution on the inner wall of the glass, and then removing the solvent.
  • the structure is solidified on the glass surface.
  • the glass to be solidified may be any material as long as it is a transparent material, and the shape may be either a flat surface or a curved surface. Then, light is emitted from the inside by mercury discharge or rare gas discharge.
  • the reaction vessel 25 holds the silicon lump 40.
  • the reaction vessel 25 may hold a silicon wafer.
  • the silicon wafer is held in the reaction vessel 25 so that the surface thereof is substantially perpendicular to the laser beam.
  • the pump 22, the cooler 24, the heater 28, the thermocouple 29, the temperature detector 30 and the controller 31 generate a supercritical fluid made of CO 2 in the reaction vessel 25. Configure the “generator”.
  • the present invention is applied to a luminescent powder capable of emitting white light.
  • the present invention is also applied to a method for producing a luminescent powder capable of emitting white light.
  • the present invention is applied to a light emitting element using a luminescent powder capable of emitting white light.
  • the present invention is applied to a method for manufacturing a light-emitting element using a luminescent powder capable of emitting white light.
  • the present invention is applied to an apparatus for producing a luminescent powder capable of emitting white light.

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  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
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Abstract

Luminescent powder (10) is produced with a first process wherein single-crystal silicon is maintained in a super-critical fluid comprising carbon dioxide and a second process wherein laser light, having an intensity which gives rise to laser ablation where nano-size silicon crystals are dispersed from the single-crystal silicon into the super-critical fluid, is directed onto the single-crystal silicon.  As a result the luminescent powder (10) comprises crystalline silicon (1) which has a spherical form, with silicon oxide (2) covering the outside of the crystalline silicon (1).  The diameter of the crystalline silicon (1) is about 2 nm and the thickness of the silicon oxide (2) is about 2 nm.  Hence, the luminescent powder (10) has a spherical form of diameter about 6 nm.

Description

発光粉体、その製造方法、発光粉体を用いた発光素子、発光素子の製造方法および発光粉体の製造装置Luminescent powder, method for producing the same, light emitting element using the luminescent powder, method for producing the light emitting element, and apparatus for producing the luminescent powder
　この発明は、発光粉体、その製造方法、発光粉体を用いた発光素子、発光素子の製造方法および発光粉体の製造装置に関するものである。 The present invention relates to a luminescent powder, a manufacturing method thereof, a light emitting element using the luminescent powder, a manufacturing method of the light emitting element, and a manufacturing apparatus of the luminescent powder.
　従来、白色で発光する酸化ケイ素膜が知られている（特許文献１）。この酸化ケイ素膜は、青色で発光する発光層Ａと、緑色で発光する発光層Ｂと、赤色で発光する発光層Ｃとを積層した構造からなる。 Conventionally, a silicon oxide film emitting white light is known (Patent Document 1). This silicon oxide film has a structure in which a light emitting layer A that emits blue light, a light emitting layer B that emits green light, and a light emitting layer C that emits red light are stacked.
　発光層Ａ，Ｂ，Ｃの各々は、酸化ケイ素と、酸化ケイ素中に含まれるナノシリコンとからなる。そして、発光層Ａ，Ｂ，Ｃに含まれるナノシリコンは、それぞれ、サイズが異なる。より具体的には、発光層Ａに含まれるナノシリコンは、１．５～２．０ｎｍのサイズを有し、発光層Ｂに含まれるナノシリコンは、２．０～２．５ｎｍのサイズを有し、発光層Ｃに含まれるナノシリコンは、２．５～３．５ｎｍのサイズを有する。 Each of the light emitting layers A, B, and C is made of silicon oxide and nanosilicon contained in the silicon oxide. The nanosilicon contained in the light emitting layers A, B, and C has different sizes. More specifically, the nanosilicon included in the light emitting layer A has a size of 1.5 to 2.0 nm, and the nanosilicon included in the light emitting layer B has a size of 2.0 to 2.5 nm. The nanosilicon contained in the light emitting layer C has a size of 2.5 to 3.5 nm.
　酸化ケイ素膜は、高周波スパッタリング法および熱処理によって製造される。より具体的には、酸化ケイ素膜は、発光層Ａの元になるアモルファス酸化ケイ素膜ａ、発光層Ｂの元になるアモルファス酸化ケイ素膜ｂ、および発光層Ｃの元になるアモルファス酸化ケイ素膜ｃを高周波スパッタリング法によって基板上に順次積層し、その積層した積層体を熱処理することによって製造される。 The silicon oxide film is manufactured by a high frequency sputtering method and a heat treatment. More specifically, the silicon oxide film includes an amorphous silicon oxide film a that is the source of the light emitting layer A, an amorphous silicon oxide film b that is the source of the light emitting layer B, and an amorphous silicon oxide film c that is the source of the light emitting layer C. Are sequentially laminated on a substrate by a high frequency sputtering method, and the laminated body is heat-treated.
　この場合、アモルファス酸化ケイ素膜ａ，ｂ，ｃは、相互に異なる量のシリコン原子を含む。 In this case, the amorphous silicon oxide films a, b, and c contain different amounts of silicon atoms.
　このように、酸化ケイ素膜は、シリコン原子の量が異なるアモルファス酸化ケイ素膜ａ，ｂ，ｃを順次積層し、その積層した積層体を熱処理して異なるサイズのナノシリコンを含む発光層Ａ，Ｂ，Ｃを形成することによって製造される。
特開２００７－６３３７８号公報 As described above, the silicon oxide film is formed by sequentially laminating the amorphous silicon oxide films a, b, and c having different amounts of silicon atoms, and the light-emitting layers A and B containing nano-silicones having different sizes by heat-treating the laminated bodies. , C is manufactured.
JP 2007-63378 A
　しかし、特許文献１に記載されたナノシリコンは、青、緑、および赤のいずれか１つの色で発光するため、白色で発光する発光粉体を製造することが困難であるという問題がある。 However, since the nanosilicon described in Patent Document 1 emits light in any one color of blue, green, and red, there is a problem that it is difficult to produce a luminescent powder that emits white light.
　そこで、この発明は、かかる問題を解決するためになされたものであり、その目的は、白色で発光可能な発光粉体を提供することである。 Therefore, the present invention has been made to solve such a problem, and an object thereof is to provide a luminescent powder capable of emitting white light.
　また、この発明の別の目的は、白色で発光可能な発光粉体の製造方法を提供することである。 Another object of the present invention is to provide a method for producing a luminescent powder capable of emitting white light.
　さらに、この発明の別の目的は、白色で発光可能な発光粉体を用いた発光素子を提供することである。 Furthermore, another object of the present invention is to provide a light emitting device using a luminescent powder capable of emitting white light.
　さらに、この発明の別の目的は、白色で発光可能な発光粉体を用いた発光素子の製造方法を提供することである。 Furthermore, another object of the present invention is to provide a method for manufacturing a light emitting device using a luminescent powder capable of emitting white light.
　さらに、この発明の別の目的は、白色で発光可能な発光粉体の製造装置を提供することである。 Furthermore, another object of the present invention is to provide an apparatus for producing a luminescent powder capable of emitting white light.
　この発明によれば、発光粉体は、二酸化炭素からなる超臨界流体中に単結晶シリコンを保持する第１の工程と、ナノサイズの結晶シリコンが単結晶シリコンから超臨界流体中へ飛び出すレーザアブレーションが生じる強度を有するレーザ光を単結晶シリコンに照射する第２の工程とを実行して製造される発光粉体である。 According to this invention, the luminescent powder includes a first step of holding single crystal silicon in a supercritical fluid made of carbon dioxide, and laser ablation in which nano-sized crystal silicon jumps out of the single crystal silicon into the supercritical fluid. Is a luminescent powder produced by performing a second step of irradiating a single crystal silicon with a laser beam having an intensity of generating
　好ましくは、発光粉体は、超臨界流体中へ飛び出したナノサイズの結晶シリコンを超臨界流体の圧力によって決定された成長時間だけ成長させる第３の工程をさらに実行して製造される発光粉体である。 Preferably, the luminescent powder is produced by further performing a third step of growing nano-sized crystalline silicon that has jumped into the supercritical fluid for a growth time determined by the pressure of the supercritical fluid. It is.
　好ましくは、第３の工程において、ナノサイズの結晶シリコンは、超臨界流体の圧力が高い程、長い時間、成長し、超臨界流体の圧力が低い程、短い時間、成長する。 Preferably, in the third step, the nano-sized crystalline silicon grows for a longer time as the pressure of the supercritical fluid is higher, and grows for a shorter time as the pressure of the supercritical fluid is lower.
　また、この発明によれば、発光粉体の製造方法は、二酸化炭素からなる超臨界流体中に単結晶シリコンを保持する第１の工程と、ナノサイズの結晶シリコンが単結晶シリコンから超臨界流体中へ飛び出すレーザアブレーションが生じる強度を有するレーザ光を単結晶シリコンに照射する第２の工程とを備える。 In addition, according to the present invention, a method for producing a luminescent powder includes a first step of holding single crystal silicon in a supercritical fluid made of carbon dioxide, and a nanosize crystalline silicon from single crystal silicon to a supercritical fluid. A second step of irradiating the single crystal silicon with a laser beam having an intensity that causes laser ablation to jump out.
　好ましくは、発光粉体の製造方法は、超臨界流体中へ飛び出したナノサイズの結晶シリコンを超臨界流体の圧力によって決定された成長時間だけ成長させる第３の工程をさらに備える。 Preferably, the method for producing a luminescent powder further includes a third step of growing nano-sized crystalline silicon that has jumped into the supercritical fluid for a growth time determined by the pressure of the supercritical fluid.
　好ましくは、第３の工程において、ナノサイズの結晶シリコンは、超臨界流体の圧力が高い程、長い時間、成長し、超臨界流体の圧力が低い程、短い時間、成長する。 Preferably, in the third step, the nano-sized crystalline silicon grows for a longer time as the pressure of the supercritical fluid is higher, and grows for a shorter time as the pressure of the supercritical fluid is lower.
　好ましくは、第１の工程は、単結晶シリコンを反応容器内に入れる第１のサブ工程と、二酸化炭素をサイフォン式のボンベから取り出し、耐膨潤性のある材料によってシールされた圧力弁、潤滑材を取り除いて作製されたポンプ、およびオイルフリーの配管を用いて超臨界流体が生成される圧力になるように反応容器に、取り出した二酸化炭素を供給する第２のサブ工程と、超臨界流体が生成される温度になるように反応容器を加熱する第３のサブ工程とを含む。 Preferably, the first step includes a first sub-step of putting single crystal silicon into the reaction vessel, a pressure valve and a lubricant which are taken out of a siphon type cylinder and sealed with a swelling-resistant material. A second sub-process for supplying the extracted carbon dioxide to the reaction vessel so as to obtain a pressure at which the supercritical fluid is generated using a pump produced by removing the oil and an oil-free pipe; And a third sub-step of heating the reaction vessel to a temperature that is generated.
　さらに、この発明によれば、発光素子は、発光部材と、第１および第２の電極とを備える。第１の電極は、発光部材の一方の表面に形成される。第２の電極は、発光部材の他方の表面に形成される。そして、発光部材は、複数の発光粉体からなる。複数の発光粉体の各々は、請求項１から請求項３のいずれか１項に記載の発光粉体からなる。 Furthermore, according to the present invention, the light emitting element includes a light emitting member and first and second electrodes. The first electrode is formed on one surface of the light emitting member. The second electrode is formed on the other surface of the light emitting member. The light emitting member is made of a plurality of light emitting powders. Each of the plurality of luminescent powders comprises the luminescent powder according to any one of claims 1 to 3.
　好ましくは、第１および第２の電極の少なくとも一方の電極は、透明導電膜からなる。 Preferably, at least one of the first and second electrodes is made of a transparent conductive film.
　好ましくは、第１および第２の電極の少なくとも一方の電極は、複数の電極片からなる。 Preferably, at least one of the first and second electrodes is composed of a plurality of electrode pieces.
　さらに、この発明によれば、発光素子の製造方法は、複数の発光粉体を製造する第１の工程と、複数の発光粉体を収集して複数の発光粉体からなる発光部材を製造する第２の工程と、基板上に形成された第１の電極に発光部材を接着する第３の工程と、発光部材上に第２の電極を形成する第４の工程とを備える。そして、第１の工程は、二酸化炭素からなる超臨界流体中に単結晶シリコンを保持する第１のサブ工程と、ナノサイズの結晶シリコンが単結晶シリコンから超臨界流体中へ飛び出すレーザアブレーションが生じる強度を有するレーザ光を単結晶シリコンに照射する第２のサブ工程とを含む。 Furthermore, according to this invention, the method for manufacturing a light emitting element includes a first step of manufacturing a plurality of light emitting powders, and a light emitting member made of a plurality of light emitting powders by collecting the plurality of light emitting powders. A second step, a third step of bonding the light emitting member to the first electrode formed on the substrate, and a fourth step of forming the second electrode on the light emitting member. The first step includes a first sub-step of holding single crystal silicon in a supercritical fluid made of carbon dioxide, and laser ablation in which nano-sized crystal silicon jumps out of the single crystal silicon into the supercritical fluid. And a second sub-step of irradiating the single crystal silicon with laser light having intensity.
　さらに、この発明によれば、発光粉体の製造装置は、反応容器と、生成器と、レーザ装置とを備える。反応容器は、単結晶シリコンを保持する。生成器は、反応容器に液体の二酸化炭素を供給し、反応容器内に二酸化炭素からなる超臨界流体を生成する。レーザ装置は、ナノサイズの結晶シリコンが単結晶シリコンから超臨界流体中へ飛び出すレーザアブレーションが生じる強度を有するレーザ光を単結晶シリコンに照射する。 Furthermore, according to this invention, the manufacturing apparatus of luminescent powder is equipped with the reaction container, the generator, and the laser apparatus. The reaction vessel holds single crystal silicon. The generator supplies liquid carbon dioxide to the reaction vessel, and generates a supercritical fluid made of carbon dioxide in the reaction vessel. The laser device irradiates single crystal silicon with laser light having an intensity that causes laser ablation in which nano-sized crystal silicon jumps out of single crystal silicon into a supercritical fluid.
　この発明によれば、発光粉体は、ＣＯ２からなる超臨界流体中に保持された単結晶シリコンからレーザアブレーションによって製造された発光粉体からなる。そして、発光粉体は、白色の蛍光を発する。 According to the present invention, the luminescent powder is made of luminescent powder produced by laser ablation from single crystal silicon held in a supercritical fluid made of CO 2 . The luminescent powder emits white fluorescence.
　したがって、この発明によれば、発光粉体を白色で発光させることができる。 Therefore, according to the present invention, the luminescent powder can emit white light.
この発明の実施の形態による発光粉体の断面図である。It is sectional drawing of the luminescent powder by embodiment of this invention. この発明の実施の形態による発光粉体の製造装置の構成を示す概略図である。It is the schematic which shows the structure of the manufacturing apparatus of the luminescent powder by embodiment of this invention. 図１に示す発光粉体の製造方法を示す工程図である。It is process drawing which shows the manufacturing method of the luminescent powder shown in FIG. 基板上に堆積された発光粉体の模式図である。It is a schematic diagram of the luminescent powder deposited on the substrate. ステンレス基板上に配置された複数の発光粉体の光学顕微鏡像である。It is an optical microscope image of the several luminescent powder arrange | positioned on the stainless steel board | substrate. Ｘ線小角散乱による分析結果を示す図である。It is a figure which shows the analysis result by X-ray small angle scattering. ラマン散乱のスペクトルを示す図である。It is a figure which shows the spectrum of a Raman scattering. 図３に示す工程に従って製造した発光粉体の蛍光顕微鏡像である。It is a fluorescence microscope image of the luminescent powder manufactured according to the process shown in FIG. ステンレス基板上に配置された複数の発光粉体の他の光学顕微鏡像である。It is another optical microscope image of the several luminescent powder arrange | positioned on the stainless steel board | substrate. 図３に示す工程に従って製造した発光粉体の他の蛍光顕微鏡像である。It is another fluorescence microscope image of the luminescent powder manufactured according to the process shown in FIG. 図３に示す工程に従って製造した発光粉体のフォトルミネッセンスのスペクトルである。Fig. 4 is a photoluminescence spectrum of a luminescent powder produced according to the process shown in Fig. 3. 発光スペクトルの積分強度の圧力依存性を示す図である。It is a figure which shows the pressure dependence of the integrated intensity | strength of an emission spectrum. この発明の実施の形態による発光素子の構成を示す断面図である。It is sectional drawing which shows the structure of the light emitting element by embodiment of this invention. 図１３に示す発光素子の製造方法を示す工程図である。It is process drawing which shows the manufacturing method of the light emitting element shown in FIG. この発明の実施の形態による他の発光素子の構成を示す断面図である。It is sectional drawing which shows the structure of the other light emitting element by embodiment of this invention. 図１５に示すＢ方向から見た電極の平面図である。It is a top view of the electrode seen from the B direction shown in FIG.
本発明の実施の形態について図面を参照しながら詳細に説明する。なお、図中同一または相当部分には同一符号を付してその説明は繰返さない。 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.
　図１は、この発明の実施の形態による発光粉体の断面図である。図１を参照して、この発明の実施の形態による発光粉体１０は、結晶シリコン１と、酸化シリコン２とを備える。酸化シリコン２は、結晶シリコン１を覆う。したがって、発光粉体１０は、結晶シリコン１をコアとするコア／シェル構造からなる。 FIG. 1 is a cross-sectional view of a luminescent powder according to an embodiment of the present invention. Referring to FIG. 1, luminescent powder 10 according to an embodiment of the present invention includes crystalline silicon 1 and silicon oxide 2. The silicon oxide 2 covers the crystalline silicon 1. Therefore, the luminescent powder 10 has a core / shell structure with the crystalline silicon 1 as a core.
　結晶シリコン１は、単結晶シリコンからなり、球形状を有する。そして、結晶シリコン１は、約２ｎｍの平均粒径を有する。酸化シリコン２は、二酸化ケイ素（ＳｉＯ２）からなり、平均で約２ｎｍの厚みを有する。したがって、発光粉体１０は、約６ｎｍの直径を有する球形状からなる。 The crystalline silicon 1 is made of single crystal silicon and has a spherical shape. The crystalline silicon 1 has an average particle diameter of about 2 nm. The silicon oxide 2 is made of silicon dioxide (SiO 2 ) and has an average thickness of about 2 nm. Therefore, the luminescent powder 10 has a spherical shape having a diameter of about 6 nm.
　図２は、この発明の実施の形態による発光粉体の製造装置の構成を示す概略図である。図２を参照して、発光粉体の製造装置１００は、ボンベ２０と、配管２１，２３と、ポンプ２２と、冷却器２４と、反応容器２５と、レーザ装置２６と、レンズ２７と、ヒータ２８と、熱電対２９と、温度検出器３０と、制御器３１とを備える。 FIG. 2 is a schematic diagram showing a configuration of a luminescent powder manufacturing apparatus according to an embodiment of the present invention. Referring to FIG. 2, the luminescent powder manufacturing apparatus 100 includes a cylinder 20, pipes 21 and 23, a pump 22, a cooler 24, a reaction vessel 25, a laser device 26, a lens 27, and a heater. 28, a thermocouple 29, a temperature detector 30, and a controller 31.
　ボンベ２０は、配管２１によってポンプ２２に接続される。ポンプ２２は、配管２３によって反応容器２５に接続される。ヒータ２８は、反応容器２５の周囲に接して配置される。これは、反応容器２５内に生成された超臨界流体を均一に加熱するためである。熱電対２９は、一方端側が反応容器２５内に挿入され、他方端が温度検出器３０に接続される。 The cylinder 20 is connected to the pump 22 by a pipe 21. The pump 22 is connected to the reaction vessel 25 by a pipe 23. The heater 28 is disposed in contact with the periphery of the reaction vessel 25. This is for heating the supercritical fluid generated in the reaction vessel 25 uniformly. One end of the thermocouple 29 is inserted into the reaction vessel 25 and the other end is connected to the temperature detector 30.
　ボンベ２０は、圧力弁２０１を有し、サイフォン式のＣＯ２ボンベからなる。そして、ボンベ２０は、気体の二酸化炭素（ＣＯ２）を収納する。配管２１は、オイルフリーの配管からなり、ボンベ２０に収納されたＣＯ２を圧力弁２０１を介してポンプ２２へ供給する。そして、圧力弁２０１は、ＣＯ２の耐膨潤性のある材料（たとえば、エチレンプロピレンゴム、ニトリルゴムおよびクロロピレンゴム）によってシールされている。 The cylinder 20 has a pressure valve 201 and is a siphon type CO 2 cylinder. The cylinder 20 stores gaseous carbon dioxide (CO 2 ). The pipe 21 is an oil-free pipe and supplies CO 2 stored in the cylinder 20 to the pump 22 via the pressure valve 201. The pressure valve 201 is sealed with a CO 2 swelling-resistant material (for example, ethylene propylene rubber, nitrile rubber, and chloropyrene rubber).
　ポンプ２２は、潤滑材を取り除いて作製されている。そして、ポンプ２２は、配管２１を介してボンベ２０から供給されたＣＯ２を配管２３を介して反応容器２５内へ供給する。この場合、ポンプ２２は、ＣＯ２からなる超臨界流体が反応容器２５内で生成される圧力になるようにＣＯ２を配管２３を介して反応容器２５内へ供給する。 The pump 22 is manufactured by removing the lubricant. Then, the pump 22 supplies CO 2 supplied from the cylinder 20 via the pipe 21 into the reaction vessel 25 via the pipe 23. In this case, the pump 22 supplies a supercritical fluid composed of CO 2 via the CO 2 piping 23 so that the pressure generated in the reaction vessel 25 within the reaction vessel 25.
　配管２３は、オイルフリーの配管からなり、ポンプ２２からのＣＯ２を反応容器２５内に供給する。冷却器２４は、たとえば、氷からなり、ポンプ２２から出力されたＣＯ２が液体のＣＯ２になる温度にＣＯ２を冷却する。 The pipe 23 is an oil-free pipe, and supplies CO 2 from the pump 22 into the reaction vessel 25. Cooler 24, for example, made from the ice, CO 2 output from the pump 22 to cool the CO 2 to the temperature at which CO 2 liquid.
　反応容器２５は、耐膨潤性のある材料（たとえば、テフロン（登録商標）、カルレッツ、シリコンゴム）によってシールされている。そして、反応容器２５は、中空の円筒形状を有し、たとえば、ステンレスからなる。また、反応容器２５は、長さ方向の両端部に、透明な窓、たとえば、サファイア窓２５１，２５２を有する。また、反応容器２５は、ＣＯ２からなる超臨界流体と、単結晶シリコンからなるシリコン塊４０と、基板５０とを保持する。 The reaction vessel 25 is sealed with a material having swelling resistance (for example, Teflon (registered trademark), Kalrez, silicon rubber). The reaction vessel 25 has a hollow cylindrical shape and is made of, for example, stainless steel. Moreover, the reaction container 25 has transparent windows, for example, sapphire windows 251 and 252 at both ends in the length direction. The reaction vessel 25 holds a supercritical fluid made of CO 2 , a silicon lump 40 made of single crystal silicon, and a substrate 50.
　レーザ装置２６は、たとえば、Ｎｄ：ＹＡＧレーザからなり、Ｎｄ：ＹＡＧレーザの２倍波である５３２ｎｍの波長を有するレーザ光を出射する。このレーザ光は、パルス幅が１０ｎｓｅｃであり、繰返し周波数が２０Ｈｚであり、フルーエンスが１９ｍＪ／ｃｍ２であるパルス光からなる。 The laser device 26 is composed of, for example, an Nd: YAG laser and emits laser light having a wavelength of 532 nm, which is a second harmonic of the Nd: YAG laser. This laser beam is composed of pulsed light having a pulse width of 10 nsec, a repetition frequency of 20 Hz, and a fluence of 19 mJ / cm 2 .
　レンズ２７は、レーザ装置２６から出射されたレーザ光を集光し、その集光したレーザ光をサファイア窓２５２を介してシリコン塊４０に照射する。この場合、レンズ２７は、１パルス当たりのエネルギーが１９ｍＪ／パルスから８００ｍＪ／パルスになるようにレーザ光を集光する。また、シリコン塊４０は、たとえば、１辺の長さが１ｃｍである立方体からなり、（１１１）の面方位を有する。さらに、基板５０は、たとえば、カーボン（Ｃ）またはステンレスからなる。そして、基板５０は、レーザ光が照射されるシリコン塊４０の面と反対面側に配置される。これは、小さいサイズの発光粉体１０を得るためである。 The lens 27 condenses the laser light emitted from the laser device 26 and irradiates the silicon lump 40 with the condensed laser light through the sapphire window 252. In this case, the lens 27 condenses the laser light so that the energy per pulse is changed from 19 mJ / pulse to 800 mJ / pulse. The silicon lump 40 is made of, for example, a cube having a side length of 1 cm and has a (111) plane orientation. Further, the substrate 50 is made of, for example, carbon (C) or stainless steel. And the board | substrate 50 is arrange | positioned on the surface opposite to the surface of the silicon lump 40 to which a laser beam is irradiated. This is to obtain a light emitting powder 10 having a small size.
　ヒータ２８は、制御器３１からの制御に従って、反応容器２５内のＣＯ２が超臨界流体になる温度に反応容器２５を加熱する。熱電対２９は、反応容器２５内のＣＯ２の温度に起因する起電力を検出し、その検出した起電力を温度検出器３０へ出力する。 The heater 28 heats the reaction vessel 25 to a temperature at which CO 2 in the reaction vessel 25 becomes a supercritical fluid in accordance with control from the controller 31. The thermocouple 29 detects an electromotive force due to the temperature of CO 2 in the reaction vessel 25 and outputs the detected electromotive force to the temperature detector 30.
　温度検出器３０は、熱電対２９から起電力を受け、その受けた起電力に基づいて、ＣＯ２の温度Ｔを検出する。そして、温度検出器３０は、その検出した温度Ｔを制御器３１へ出力する。 The temperature detector 30 receives an electromotive force from the thermocouple 29, and detects the temperature T of CO 2 based on the received electromotive force. Then, the temperature detector 30 outputs the detected temperature T to the controller 31.
　制御器３１は、温度検出器３０から温度Ｔを受け、その受けた温度Ｔに基づいて、反応容器２５内のＣＯ２が超臨界流体になる温度Ｔｃに反応容器２５を加熱するようにヒータ２８を制御する。 The controller 31 receives the temperature T from the temperature detector 30 and, based on the received temperature T, the heater 28 so as to heat the reaction vessel 25 to a temperature Tc at which CO 2 in the reaction vessel 25 becomes a supercritical fluid. To control.
　ＣＯ２を反応容器２５内に４．５６ＭＰａ～１４．８ＭＰａの圧力範囲で詰める方法について説明する。図２においては、図示されていないが、製造装置１００は、反応容器２５内の圧力を測定する圧力計と、反応容器２５内のＣＯ２を外部へ放出するための開閉弁とを備えている。そして、反応容器２５内の圧力が設定圧力（＝４．５６ＭＰａ～１４．８ＭＰａの圧力範囲のいずれかの圧力）よりも高い圧力になるように、ボンベ２０、配管２１，２３、ポンプ２２および冷却器２４を用いてＣＯ２を反応容器２５内に詰める。そして、開閉弁を開いてＣＯ２を外部へ放出し、反応容器２５内の圧力を設定圧力に設定する。 A method of filling CO 2 in the reaction vessel 25 in the pressure range of 4.56 MPa to 14.8 MPa will be described. Although not shown in FIG. 2, the manufacturing apparatus 100 includes a pressure gauge for measuring the pressure in the reaction vessel 25 and an on-off valve for releasing CO 2 in the reaction vessel 25 to the outside. . The cylinder 20, the pipes 21, 23, the pump 22, and the cooling are performed so that the pressure in the reaction vessel 25 becomes higher than the set pressure (= any pressure in the pressure range of 4.56 MPa to 14.8 MPa). CO 2 is packed into the reaction vessel 25 using the vessel 24. Then, the on-off valve is opened to release CO 2 to the outside, and the pressure in the reaction vessel 25 is set to the set pressure.
　なお、図２においては、図示されていないが、ＣＯ２をボンベ２０から反応容器２５へ供給する経路には、高圧バルブも使用されており、高圧バルブ（ダイヤフラム型）は、オイルフリーのバルブからなる。 Although not shown in FIG. 2, a high-pressure valve is also used in the path for supplying CO 2 from the cylinder 20 to the reaction vessel 25. The high-pressure valve (diaphragm type) is connected to the oil-free valve. Become.
　この発明の実施の形態においては、ポンプ２２は、反応容器２５内の圧力が４．５６ＭＰａ～１４．８ＭＰａの範囲になるようにＣＯ２を反応容器２５内に供給する。また、ヒータ２８は、反応容器２５内のＣＯ２の温度Ｔが４０℃～５０℃の範囲になるように反応容器２５を加熱する。 In the embodiment of the present invention, the pump 22 supplies CO 2 into the reaction vessel 25 so that the pressure in the reaction vessel 25 is in the range of 4.56 MPa to 14.8 MPa. The heater 28 heats the reaction container 25 so that the temperature T of CO 2 in the reaction container 25 is in the range of 40 ° C. to 50 ° C.
　そして、反応容器２５内の圧力が４．５６ＭＰａ～１４．８ＭＰａの範囲になり、反応容器２５内のＣＯ２の温度Ｔが臨界温度である３１℃以上、たとえば、４０℃～５０℃の範囲になれば、反応容器２５内のＣＯ２は、超臨界流体になる。 The pressure in the reaction vessel 25 is in the range of 4.56 MPa to 14.8 MPa, and the temperature T of CO 2 in the reaction vessel 25 is not less than the critical temperature of 31 ° C., for example, in the range of 40 ° C. to 50 ° C. If it becomes, the CO 2 in the reaction vessel 25 becomes a supercritical fluid.
　また、製造装置１００においては、ポンプ２２から出力された気体のＣＯ２を液体のＣＯ２になるように冷却器２４によって冷却しているが、これは、液体のＣＯ２の方が気体のＣＯ２よりもポンプ２２によって加圧し易いため、反応容器２５内のＣＯ２の圧力をポンプ２２によって４．５６ＭＰａ～１４．８ＭＰａの圧力に設定し易くするためである。つまり、ＣＯ２からなる超臨界流体を安定して作り出すためである。 Further, in the manufacturing apparatus 100, the gaseous CO 2 output from the pump 22 is cooled by the cooler 24 so as to become liquid CO 2. This is because liquid CO 2 is more gaseous CO 2. This is because the pressure of CO 2 in the reaction vessel 25 is easily set to a pressure of 4.56 MPa to 14.8 MPa by the pump 22 because it is easier to pressurize by the pump 22 than 2 . That is, it is for stably producing a supercritical fluid composed of CO 2 .
　さらに、製造装置１００においては、上述したように、ポンプ２２は、潤滑材を取り除いて作製されており、配管２１，２３および高圧バルブがそれぞれオイルフリーの配管およびバルブからなるので、ＣＯ２からなる超臨界流体を反応容器２５内で安定させることができるとともに、製造された発光粉体１０への汚染を抑制できる。 Further, in the manufacturing apparatus 100, as described above, the pump 22 is manufactured by removing the lubricant, since the pipe 21, 23 and the high pressure valve consists of oil-free respective piping and valves, consisting of CO 2 The supercritical fluid can be stabilized in the reaction vessel 25, and contamination of the manufactured luminescent powder 10 can be suppressed.
　さらに、製造装置１００においては、上述したように、ボンベ２０は、サイフォン式のＣＯ２ボンベからなるので、短時間で効率的に高密度のＣＯ２をボンベ２０から取り出すことができる。 Furthermore, in the manufacturing apparatus 100, as described above, since the cylinder 20 is a siphon type CO 2 cylinder, high-density CO 2 can be efficiently extracted from the cylinder 20 in a short time.
　図３は、図１に示す発光粉体１０の製造方法を示す工程図である。図３を参照して、発光粉体１０の製造が開始されると、シリコン塊４０が反応容器２５内に設置される（ステップＳ１）。 FIG. 3 is a process diagram showing a manufacturing method of the luminescent powder 10 shown in FIG. Referring to FIG. 3, when the production of luminescent powder 10 is started, silicon lump 40 is installed in reaction vessel 25 (step S1).
　そして、圧力弁２０１は、ボンベ２０からの気体のＣＯ２を配管２１を介してポンプ２２に供給し、ポンプ２２は、ＣＯ２を配管２３中へ出力する。そして、冷却器２４は、気体のＣＯ２を液体のＣＯ２に冷却する。そうすると、ポンプ２２は、その冷却された液体のＣＯ２を反応容器２５内で超臨界流体が生成される圧力になるように反応容器２５へ供給する（ステップＳ２）。 The pressure valve 201 supplies gaseous CO 2 from the cylinder 20 to the pump 22 via the pipe 21, and the pump 22 outputs CO 2 into the pipe 23. The cooler 24 cools gaseous CO 2 to liquid CO 2 . Then, the pump 22 supplies the cooled liquid CO 2 to the reaction vessel 25 so as to have a pressure at which a supercritical fluid is generated in the reaction vessel 25 (step S2).
　その後、熱電対２９は、反応容器２５内のＣＯ２の温度に起因する起電力を検出し、その検出した起電力を温度検出器３０へ出力する。温度検出器３０は、熱電対２９から受けた起電力に基づいて、反応容器２５内のＣＯ２の温度Ｔを検出し、その検出した温度Ｔを制御器３１へ出力する。 Thereafter, the thermocouple 29 detects an electromotive force due to the temperature of CO 2 in the reaction vessel 25 and outputs the detected electromotive force to the temperature detector 30. The temperature detector 30 detects the temperature T of CO 2 in the reaction vessel 25 based on the electromotive force received from the thermocouple 29 and outputs the detected temperature T to the controller 31.
　制御器３１は、温度検出器３０から受けた温度Ｔが、ＣＯ２からなる超臨界流体が生成される温度Ｔｃになるようにヒータ２８を制御する。そして、ヒータ２８は、温度Ｔが温度Ｔｃになるように反応容器２５を加熱する（ステップＳ３）。 The controller 31 controls the heater 28 so that the temperature T received from the temperature detector 30 becomes the temperature Tc at which a supercritical fluid made of CO 2 is generated. Then, the heater 28 heats the reaction vessel 25 so that the temperature T becomes the temperature Tc (step S3).
　引き続いて、レーザ装置２６は、レーザアブレーションが生じる強度（＝８００ｍＪ／パルス）を有するレーザ光をレンズ２７を介してシリコン塊４０に照射する（ステップＳ４）。この場合、レーザ光の照射時間は、約５分～１０分である。また、レーザ装置２６は、たとえば、約４０秒、レーザ光をシリコン塊４０の一箇所に照射し、その後、照射場所を数ｍｍずらして、約４０秒、レーザ光をシリコン塊４０に照射することを繰り返す。また、反応容器２５に入射されるレーザ光の入射位置を固定し、ターゲットとなるシリコン塊４０を回転または移動させることによって、シリコン塊４０におけるレーザ光の照射位置を変えてもよい。このように、レーザ光の照射場所を変えながらレーザ光をシリコン塊４０に照射することによって、４倍程度、多くの発光粉体１０を製造できる。 Subsequently, the laser device 26 irradiates the silicon block 40 with a laser beam having an intensity (= 800 mJ / pulse) at which laser ablation occurs (step S4). In this case, the laser beam irradiation time is about 5 to 10 minutes. Further, the laser device 26 irradiates the silicon lump 40 with laser light for about 40 seconds, and then irradiates the silicon lump 40 with laser light for about 40 seconds after shifting the irradiation position by several mm. repeat. Further, the irradiation position of the laser beam in the silicon lump 40 may be changed by fixing the incident position of the laser beam incident on the reaction vessel 25 and rotating or moving the silicon lump 40 as a target. Thus, by irradiating the silicon lump 40 with the laser light while changing the irradiation place of the laser light, many light emitting powders 10 can be manufactured about four times.
　これによって、レーザアブレーションが起こり、ナノサイズの結晶シリコンがシリコン塊４０から超臨界流体（＝ＣＯ２）中へ飛び出す。 As a result, laser ablation occurs, and nano-sized crystalline silicon jumps out of the silicon mass 40 into the supercritical fluid (= CO 2 ).
　レーザ光の照射時間が１０分になると、レーザ装置２６は、レーザ光の照射を停止する（ステップＳ５）。 When the laser beam irradiation time is 10 minutes, the laser device 26 stops the laser beam irradiation (step S5).
　その後、反応容器２５内の圧力によって決定された成長時間だけ反応容器２５中でナノ生成物を成長させる（ステップＳ６）。この成長によって、超臨界流体中へ飛び出した結晶シリコンは、レーザ光の照射直後のナノ秒からピコ秒のタームスケールで超臨界ＣＯ２によって冷却され、超臨界流体中を下方向へ移動しながら発光粉体１０になり、発光粉体１０が基板５０上に堆積される。これらの間、反応容器２５は、同一温度になるように制御器３１によって制御されている。 Thereafter, nano products are grown in the reaction vessel 25 for the growth time determined by the pressure in the reaction vessel 25 (step S6). Due to this growth, crystalline silicon that has jumped into the supercritical fluid is cooled by supercritical CO 2 at the nanosecond to picosecond term scale immediately after laser light irradiation, and emits light while moving downward in the supercritical fluid. The luminescent powder 10 is deposited on the substrate 50. During these periods, the reaction vessel 25 is controlled by the controller 31 so as to have the same temperature.
　また、成長時間は、反応容器２５内の圧力が４．５６ＭＰａである場合、４分～１０分であり、反応容器２５内の圧力が１１．０ＭＰａである場合、１時間であり、反応容器２５内の圧力が１４．８ＭＰａである場合、２時間である。これらの時間は、１００ｎｍの粒子が１ｃｍだけ沈む時間を計算し、その計算した時間に基づいて決定された。 The growth time is 4 to 10 minutes when the pressure in the reaction vessel 25 is 4.56 MPa, and 1 hour when the pressure in the reaction vessel 25 is 11.0 MPa. When the internal pressure is 14.8 MPa, it is 2 hours. These times were determined based on the calculated time for 100 nm particles to sink by 1 cm.
　このように、成長時間は、ＣＯ２からなる超臨界流体の圧力が高い程、長い時間に設定され、ＣＯ２からなる超臨界流体の圧力が低い程、短い時間に設定される。 Thus, the growth time is set to a longer time as the pressure of the supercritical fluid made of CO 2 is higher, and is set to a shorter time as the pressure of the supercritical fluid made of CO 2 is lower.
　そして、成長時間が経過すると、発光粉体１０の製造が終了する。 Then, when the growth time has elapsed, the production of the luminescent powder 10 is finished.
　上述したように、この発明の実施の形態においては、レーザ光の照射を停止した後、超臨界流体の圧力によって決定された成長時間だけ、反応容器２５内のＣＯ２およびレーザアブレーションによって生成された結晶シリコンを冷却し、発光粉体１０を基板５０上に堆積させる。 As described above, in the embodiment of the present invention, after the irradiation with the laser beam is stopped, the growth time determined by the pressure of the supercritical fluid is generated by the CO 2 in the reaction vessel 25 and the laser ablation. The crystalline silicon is cooled and the luminescent powder 10 is deposited on the substrate 50.
　なお、図３に示す工程においては、レーザ装置２６は、レーザ光をレンズ２７によって集光し、８００ｍＪ／パルスの強度を有するレーザ光をシリコン塊４０に照射すると説明したが、この発明の実施の形態においては、これに限らず、レーザ装置２６は、ナノサイズの結晶シリコンがシリコン塊４０から超臨界流体中へ飛び出すレーザアブレーションが生じる臨界強度である２００ｍＪ／パルス以上の強度を有するレーザ光をレンズ２７を介してシリコン塊４０に照射するものであればよい。 In the process shown in FIG. 3, it has been described that the laser device 26 condenses the laser light by the lens 27 and irradiates the silicon lump 40 with the laser light having an intensity of 800 mJ / pulse. In the embodiment, the laser device 26 is not limited to this, and the laser device 26 uses laser light having an intensity of 200 mJ / pulse or more, which is a critical intensity at which laser ablation occurs in which nano-sized crystalline silicon jumps out of the silicon mass 40 into the supercritical fluid. What is necessary is just to irradiate the silicon lump 40 via 27.
　図４は、基板５０上に堆積された発光粉体１０の模式図である。なお、図４は、基板５０上に堆積された複数の発光粉体１０の一部を拡大して示したものである。 FIG. 4 is a schematic diagram of the luminescent powder 10 deposited on the substrate 50. FIG. 4 is an enlarged view of a part of the plurality of luminescent powders 10 deposited on the substrate 50.
　図４を参照して、発光粉体１０は、ネットワーク構造（図４の斜線部分）を形成するように基板５０上に堆積される。 Referring to FIG. 4, the luminescent powder 10 is deposited on the substrate 50 so as to form a network structure (shaded portion in FIG. 4).
　図５は、ステンレス基板上に配置された複数の発光粉体の光学顕微鏡像である。なお、図５は、図４に示すネットワーク構造を構成する複数の発光粉体１０を収集してステンレス基板上に配置したときの光学顕微鏡像（明視野像）である。そして、明視野像は、ハロゲンランプを落射照明で照射し、常温および常圧下で高感度カラーＣＣＤカメラ付き顕微鏡によって測定した。 FIG. 5 is an optical microscope image of a plurality of luminescent powders arranged on a stainless steel substrate. FIG. 5 is an optical microscope image (bright field image) when a plurality of luminescent powders 10 constituting the network structure shown in FIG. 4 are collected and arranged on a stainless steel substrate. The bright field image was measured with a microscope with a high-sensitivity color CCD camera at normal temperature and normal pressure by irradiating a halogen lamp with epi-illumination.
　図５を参照して、複数の微小な粒が写っているのが解る。 Referring to FIG. 5, it can be seen that a plurality of minute grains are shown.
　ネットワーク構造を形成する複数の発光粉体１０を収集してＥＰＭＡ（Ｅｌｅｃｔｒｏｎ　Ｐｒｏｂｅ　Ｍｉｃｒｏ　Ａｎａｌｙｚｅｒ）による分析を行なった。 A plurality of luminescent powders 10 forming a network structure were collected and analyzed by EPMA (Electron Probe Micro Analyzer).
　複数の発光粉体１０の集合体をＥＰＭＡによって分析した結果、シリコン（Ｓｉ）および酸素（Ｏ）が約１：２の組成比で検出された。したがって、発光粉体１０の表面側は、ＳｉＯ２からなることが解った。 As a result of analyzing the aggregate of the plurality of luminescent powders 10 by EPMA, silicon (Si) and oxygen (O) were detected at a composition ratio of about 1: 2. Thus, the surface side of the light emitting powder 10 was found to be composed of SiO 2.
　また、複数の発光粉体１０の集合体をＨＦに浸漬したものについてフォトルミネッセンスを測定した結果、Ｓｉの発光が検出された。したがって、発光粉体１０の中心部は、Ｓｉからなることが解った。なお、発光粉体１０のフッ酸処理は、３０％のＨＦに発光粉体１０を数時間浸漬することによって行なわれた。 Further, as a result of measuring photoluminescence of an assembly of a plurality of luminescent powders 10 immersed in HF, Si luminescence was detected. Therefore, it has been found that the central portion of the luminescent powder 10 is made of Si. The hydrofluoric acid treatment of the luminescent powder 10 was performed by immersing the luminescent powder 10 in 30% HF for several hours.
　このＥＰＭＡの分析およびフォトルミネッセンスの測定結果によって、発光粉体１０は、上述したようにＳｉをコアとし、ＳｉＯ２をシェルとするコア／シェル構造からなることが実証された。 This EPMA analysis and photoluminescence measurement results demonstrated that the luminescent powder 10 has a core / shell structure with Si as the core and SiO 2 as the shell as described above.
　次に、複数の発光粉体１０の集合体をＸ線小角散乱（ＳＡＸＳ：Ｓｍａｌｌ　Ａｎｇｌｅ　Ｘ－ｒａｙ　Ｓｃａｔｔｅｒｉｎｇ）によって分析した。 Next, the aggregate of the plurality of luminescent powders 10 was analyzed by X-ray small angle scattering (SAXS: Small Angle X-ray Scattering).
　図６は、Ｘ線小角散乱による分析結果を示す図である。なお、Ｘ線小角散乱は、波長１．５ÅのＣｕＫα線を用いて測定された。 FIG. 6 is a diagram showing an analysis result by small-angle X-ray scattering. X-ray small angle scattering was measured using CuKα rays having a wavelength of 1.5 mm.
　図６において、横軸は、サイズを表し、縦軸は、存在量を表す。また、曲線ｋ１は、ＣＯ２からなる超臨界流体の圧力を４．５６ＭＰａに設定して製造した発光粉体１０のＸ線小角散乱による分析結果を示す。さらに、曲線ｋ２は、ＣＯ２からなる超臨界流体の圧力を１０．４ＭＰａに設定して製造した発光粉体１０のＸ線小角散乱による分析結果を示す。さらに、曲線ｋ３は、Ｘ線小角散乱の典型的なスペクトルを示す。 In FIG. 6, the horizontal axis represents size, and the vertical axis represents abundance. Curve k1 shows the analysis result by X-ray small angle scattering of the luminescent powder 10 manufactured by setting the pressure of the supercritical fluid made of CO 2 to 4.56 MPa. Furthermore, a curve k2 shows the analysis result by X-ray small angle scattering of the luminescent powder 10 manufactured by setting the pressure of the supercritical fluid made of CO 2 to 10.4 MPa. Furthermore, the curve k3 shows a typical spectrum of X-ray small angle scattering.
　図６を参照して、ＣＯ２からなる超臨界流体の圧力を４．５６ＭＰａに設定して製造した発光粉体１０、およびＣＯ２からなる超臨界流体の圧力を１０．４ＭＰａに設定して製造した発光粉体１０は、共に、約０．５ｎｍ～約１００ｎｍの範囲のサイズを有し、約６ｎｍのサイズに最も多く分布する（曲線ｋ１，ｋ２参照）。 Referring to FIG. 6, by setting the light emitting powder 10 was prepared by setting the pressure of the supercritical fluid consisting CO 2 to 4.56MPa, and the pressure of the supercritical fluid consisting CO 2 to 10.4MPa production Both of the luminescent powders 10 have a size in the range of about 0.5 nm to about 100 nm and are most distributed in a size of about 6 nm (see curves k1 and k2).
　このサイズの分布と、上述したＸ線小角散乱の分析結果とを併せると、発光粉体１０は、約２ｎｍの直径を有するＳｉと、約２ｎｍの厚みを有するＳｉＯ２とからなることが解った。 Combining this size distribution with the X-ray small angle scattering analysis results described above, it was found that the luminescent powder 10 was composed of Si having a diameter of about 2 nm and SiO 2 having a thickness of about 2 nm. .
　図７は、ラマン散乱のスペクトルを示す図である。図７において、横軸は、ラマンシフトを表し、縦軸は、強度を表す。また、曲線ｋ４は、ＣＯ２からなる超臨界流体の圧力を４．５６ＭＰａに設定して製造した発光粉体１０のラマン散乱のスペクトルを示す。さらに、曲線ｋ５は、ＣＯ２からなる超臨界流体の圧力を１０．４ＭＰａに設定して製造した発光粉体１０のラマン散乱のスペクトルを示す。さらに、曲線ｋ６は、ＣＯ２からなる超臨界流体の圧力を１４．８ＭＰａに設定して製造した発光粉体１０のラマン散乱のスペクトルを示す。さらに、曲線ｋ７は、単結晶シリコンのラマン散乱のスペクトルを示す。さらに、曲線ｋ８は、アモルファスシリコンのラマン散乱のスペクトルを示す。 FIG. 7 is a diagram showing a spectrum of Raman scattering. In FIG. 7, the horizontal axis represents Raman shift, and the vertical axis represents intensity. A curve k4 shows the Raman scattering spectrum of the luminescent powder 10 produced by setting the pressure of the supercritical fluid made of CO 2 to 4.56 MPa. Furthermore, the curve k5 shows the spectrum of Raman scattering of the luminescent powder 10 produced by setting the pressure of the supercritical fluid made of CO 2 to 10.4 MPa. Furthermore, the curve k6 shows the spectrum of Raman scattering of the luminescent powder 10 produced by setting the pressure of the supercritical fluid made of CO 2 to 14.8 MPa. Furthermore, the curve k7 shows the spectrum of Raman scattering of single crystal silicon. Furthermore, the curve k8 shows the spectrum of Raman scattering of amorphous silicon.
　図７を参照して、発光粉体１０は、製造時の超臨界流体（ＣＯ２からなる）の圧力に拘わらず、ラマンシフトの鋭いピークが５２０ｃｍ－１に観測された（曲線ｋ４～ｋ６参照）。これは、単結晶シリコンのラマンシフトのピーク（５２０ｃｍ－１）と同じであり（曲線ｋ７参照）、アモルファスシリコンのラマンシフトと全く異なるものである（曲線ｋ８参照）。 Referring to FIG. 7, in the luminescent powder 10, a sharp peak of Raman shift was observed at 520 cm −1 regardless of the pressure of the supercritical fluid (consisting of CO 2 ) at the time of manufacture (see curves k4 to k6). ). This is the same as the peak of Raman shift (520 cm −1 ) of single crystal silicon (see curve k7), which is completely different from the Raman shift of amorphous silicon (see curve k8).
　したがって、発光粉体１０は、単結晶シリコンからなるコアを有することが解った。 Therefore, it was found that the luminescent powder 10 had a core made of single crystal silicon.
　図８は、図３に示す工程に従って製造した発光粉体１０の蛍光顕微鏡像である。なお、蛍光顕微鏡像を撮ったときの発光粉体１０の励起波長は、３２５ｎｍであり、励起光の強度は、２０ｍＷである。また、蛍光顕微鏡像は、常温および常圧下で撮影された。 FIG. 8 is a fluorescence microscope image of the luminescent powder 10 produced according to the process shown in FIG. In addition, the excitation wavelength of the luminescent powder 10 when a fluorescent microscope image is taken is 325 nm, and the intensity of the excitation light is 20 mW. Moreover, the fluorescence microscope image was image | photographed under normal temperature and normal pressure.
　図８を参照して、発光粉体１０は、全体的には、白水色に発光しており、矢印Ａによって示される領域では、白色で発光しているのが解る。 Referring to FIG. 8, it is understood that the luminescent powder 10 emits white light blue as a whole and emits white light in the region indicated by the arrow A.
　図９は、ステンレス基板上に配置された複数の発光粉体の他の光学顕微鏡像である。なお、光学顕微鏡像は、図５に示す光学顕微鏡像の撮影条件と同じ撮影条件によって撮影された。図９を参照して、複数の発光粉体１０からなる生成物が生成されている。そして、生成物は、突起部分を有する。 FIG. 9 is another optical microscope image of a plurality of luminescent powders arranged on a stainless steel substrate. The optical microscope image was taken under the same shooting conditions as those of the optical microscope image shown in FIG. Referring to FIG. 9, a product composed of a plurality of luminescent powders 10 is generated. And a product has a projection part.
　図１０は、図３に示す工程に従って製造した発光粉体１０の他の蛍光顕微鏡像である。なお、蛍光顕微鏡像を撮ったときの発光粉体１０の励起波長は、３２５ｎｍであり、励起光の強度は、２０ｍＷである。また、蛍光顕微鏡像は、常温および常圧下で撮影された。 FIG. 10 is another fluorescence microscopic image of the luminescent powder 10 manufactured according to the process shown in FIG. In addition, the excitation wavelength of the luminescent powder 10 when a fluorescent microscope image is taken is 325 nm, and the intensity of the excitation light is 20 mW. Moreover, the fluorescence microscope image was image | photographed under normal temperature and normal pressure.
　図１０を参照して、図９に示す領域と同じ領域が白色または白水色で発光している。図９および図１０に示す領域は、図５および図８に示す領域よりも広い領域であり、数百μｍのサイズを有する。 Referring to FIG. 10, the same region as shown in FIG. 9 emits light in white or light blue. The region shown in FIGS. 9 and 10 is wider than the region shown in FIGS. 5 and 8 and has a size of several hundred μm.
　したがって、複数の発光粉体１０の集合体は、数百μｍの領域で全体的に発光することが確認された。 Therefore, it was confirmed that the aggregate of the plurality of luminescent powders 10 totally emitted light in the region of several hundred μm.
　このように、ＣＯ２からなる超臨界流体中でシリコン塊４０からレーザアブレーションによって製造された発光粉体１０は、白水色または白色で発光することが実証された。 Thus, it was demonstrated that the luminescent powder 10 produced by laser ablation from the silicon mass 40 in a supercritical fluid made of CO 2 emits light blue or white light.
　図１１は、図３に示す工程に従って製造した発光粉体１０のフォトルミネッセンスのスペクトルである。図１１において、横軸は、波長（またはエネルギー）を表し、縦軸は、強度を表す。 FIG. 11 is a photoluminescence spectrum of the luminescent powder 10 produced according to the process shown in FIG. In FIG. 11, the horizontal axis represents wavelength (or energy), and the vertical axis represents intensity.
　なお、フォトルミネッセンスを測定するときの発光粉体１０の励起波長は、３２５ｎｍであり、励起光の強度は、２ｍＷである。そして、フォトルミネッセンスの測定は、波長３２５ｎｍのレーザ光を試料に対して落射によって照射し（試料直前における励起光の強度は、数十μＷである）、紫外対応対物レンズで試料からの発光を採光し、シングル型分光器によって波長分散させ、ＣＣＤカメラでスペクトル計測を行なうことによって測定された。スペクトルは、アメリカ国立標準技術研究所（ＮＩＳＴ）準拠の強度補正された光源を元に装置関数を得て、それを用いて分光感度特性が校正されている。測定は、常温および常圧下で行なわれた。 The excitation wavelength of the luminescent powder 10 when measuring photoluminescence is 325 nm, and the intensity of the excitation light is 2 mW. In the photoluminescence measurement, a laser beam having a wavelength of 325 nm is irradiated onto the sample by epi-illumination (the intensity of the excitation light immediately before the sample is several tens of μW), and light emitted from the sample is collected by an ultraviolet-compatible objective lens. Then, the wavelength was dispersed by a single-type spectrometer, and the spectrum was measured by a CCD camera. As for the spectrum, an instrument function is obtained based on an intensity-corrected light source compliant with the National Institute of Standards and Technology (NIST), and the spectral sensitivity characteristic is calibrated using the device function. The measurement was performed at normal temperature and normal pressure.
　また、図１１は、ＣＯ２からなる超臨界流体の圧力を７．５ＭＰａに設定し、ＣＯ２からなる超臨界流体の温度を３２２．４Ｋ（＝４９．４℃）に設定して発光粉体１０を製造し、その製造した発光粉体１０を大気中へ取り出して４日経過後に測定されたフォトルミネッセンスのスペクトルである。 Further, FIG. 11, to set the pressure of the supercritical fluid consisting CO 2 to 7.5 MPa, and the temperature of the supercritical fluid consisting CO 2 to 322.4K (= 49.4 ℃) emitting powder 10 is a spectrum of photoluminescence measured after 4 days have passed after the produced luminescent powder 10 is taken out into the atmosphere.
　図１１を参照して、発光粉体１０は、３５０ｎｍ以上の波長範囲に発光スペクトルを有することが解った。すなわち、色の三原色である青、緑および赤の波長を含む波長範囲に発光スペクトルを有する。 Referring to FIG. 11, it was found that the luminescent powder 10 had an emission spectrum in a wavelength range of 350 nm or more. That is, it has an emission spectrum in a wavelength range including the wavelengths of blue, green and red, which are the three primary colors.
　この発光スペクトルは、図８に示す蛍光顕微鏡像が白色であることを支持するものである。 This emission spectrum supports that the fluorescence microscope image shown in FIG. 8 is white.
　図１２は、発光スペクトルの積分強度の圧力依存性を示す図である。図１２において、横軸は、発光粉体１０の製造時の超臨界流体の圧力を表し、縦軸は、積分強度を表す。また、曲線ｋ９は、発光粉体１０を製造してから４０分後の発光スペクトルの積分強度の圧力依存性を示し、曲線ｋ１０は、発光粉体１０を製造してから２日後の発光スペクトルの積分強度の圧力依存性を示し、曲線ｋ１１は、発光粉体１０を製造してから２ヶ月後の発光スペクトルの積分強度の圧力依存性を示す。 FIG. 12 is a diagram showing the pressure dependence of the integrated intensity of the emission spectrum. In FIG. 12, the horizontal axis represents the pressure of the supercritical fluid at the time of manufacturing the luminescent powder 10, and the vertical axis represents the integrated intensity. Curve k9 shows the pressure dependence of the integrated intensity of the emission spectrum 40 minutes after producing the luminescent powder 10, and curve k10 shows the emission spectrum two days after producing the luminescent powder 10. The pressure dependence of the integrated intensity is shown, and the curve k11 shows the pressure dependence of the integrated intensity of the emission spectrum two months after the luminescent powder 10 is manufactured.
　図１２を参照して、発光粉体１０を製造してから４０分経過後の発光スペクトルの積分強度は、超臨界流体の圧力に対してほぼ一定である（曲線ｋ９参照）。 Referring to FIG. 12, the integrated intensity of the emission spectrum after 40 minutes from the production of the luminescent powder 10 is substantially constant with respect to the pressure of the supercritical fluid (see curve k9).
　一方、発光粉体１０を製造してから２日経過後の発光スペクトルの積分強度、および発光粉体１０を製造してから２ヶ月経過後の発光スペクトルの積分強度は、４．５６ＭＰａ～１４．８ＭＰａの圧力範囲において超臨界流体の圧力が高くなるに従って強くなる（曲線ｋ１０，ｋ１１参照）。 On the other hand, the integrated intensity of the emission spectrum after 2 days from the production of the luminescent powder 10 and the integrated intensity of the emission spectrum after 2 months from the production of the luminescent powder 10 are 4.56 MPa to 14.8 MPa. In the pressure range increases as the pressure of the supercritical fluid increases (see curves k10 and k11).
　そして、発光粉体１０を製造してから２ヶ月経過後の発光粉体１０は、発光強度（積分強度）が最大で約１００倍になる（曲線ｋ９，ｋ１１参照）。 The luminous powder 10 after two months from the production of the luminous powder 10 has a maximum luminous intensity (integrated intensity) of about 100 times (see curves k9 and k11).
　したがって、発光粉体１０を製造するときの超臨界流体の圧力を制御することによって発光強度を制御できる。 Therefore, the emission intensity can be controlled by controlling the pressure of the supercritical fluid when the luminescent powder 10 is manufactured.
　また、各圧力において、発光粉体１０の発光強度（積分強度）は、発光粉体１０を製造してからの経過時間が長くなるに従って強くなる（曲線ｋ９～ｋ１１参照）。 Also, at each pressure, the emission intensity (integrated intensity) of the luminescent powder 10 becomes stronger as the elapsed time after the luminescent powder 10 is manufactured becomes longer (see curves k9 to k11).
　したがって、図３に示す工程に従って製造された発光粉体１０は、製造されてからの経過時間によって劣化しないことが解った。 Therefore, it has been found that the luminescent powder 10 manufactured according to the process shown in FIG. 3 does not deteriorate with the elapsed time since it was manufactured.
　なお、上述した図３に示す工程において、ステップＳ１～Ｓ３は、二酸化炭素からなる超臨界流体中に単結晶シリコンを保持する「第１の工程」を構成する。 In the process shown in FIG. 3 described above, steps S1 to S3 constitute a “first process” for holding single crystal silicon in a supercritical fluid made of carbon dioxide.
　また、上述したステップＳ４において、レーザアブレーションが生じる強度を有するレーザ光を単結晶シリコンからなるシリコン塊４０に照射することによって、ナノサイズの結晶シリコンがシリコン塊４０から超臨界流体中へ飛び出すので、ステップＳ４は、ナノサイズの結晶シリコンが単結晶シリコンから超臨界流体中へ飛び出すレーザアブレーションが生じる強度を有するレーザ光を単結晶シリコンに照射する「第２の工程」を構成する。 Further, in step S4 described above, by irradiating the silicon lump 40 made of single crystal silicon with laser light having an intensity that causes laser ablation, the nano-sized crystalline silicon jumps out of the silicon lump 40 into the supercritical fluid. Step S4 constitutes a “second step” of irradiating the single crystal silicon with a laser beam having an intensity that causes laser ablation in which nano-sized crystal silicon jumps out of the single crystal silicon into the supercritical fluid.
　そして、結晶シリコンがレーザアブレーションによってシリコン塊４０から超臨界流体中へ飛び出し、その飛び出した結晶シリコンが、その後、任意の時間、冷却されれば、発光粉体１０が製造されるので、上述した成長時間が経過する前に試料を取り出しても発光粉体１０を得ることができる。したがって、この発明の実施の形態による発光粉体は、上述した第１および第２の工程によって製造されるものであればよい。 Then, the crystalline silicon jumps out of the silicon lump 40 into the supercritical fluid by laser ablation, and the luminescent powder 10 is manufactured if the jumped crystalline silicon is cooled for an arbitrary time. Even if the sample is taken out before the time elapses, the luminescent powder 10 can be obtained. Therefore, the luminescent powder according to the embodiment of the present invention only needs to be manufactured by the first and second steps described above.
　図１３は、この発明の実施の形態による発光素子の構成を示す断面図である。図１３を参照して、この発明の実施の形態による発光素子２００は、透明基板２１０と、透明導電膜２２０と、導電性高分子２３０と、発光部材２４０と、電極２５０とを備える。 FIG. 13 is a cross-sectional view showing the configuration of the light emitting device according to the embodiment of the present invention. Referring to FIG. 13, a light emitting device 200 according to an embodiment of the present invention includes a transparent substrate 210, a transparent conductive film 220, a conductive polymer 230, a light emitting member 240, and an electrode 250.
　透明基板２１０は、フィルムまたはガラスからなる。透明導電膜２２０は、ＩＴＯ（Ｉｎｄｉｕｍ　Ｔｉｎ　Ｏｘｉｄｅ）、ＳｎＯ２、ＺｎＯ、および有機ＥＬ（Ｅｌｅｃｔｒｏ　Ｌｕｍｉｎｅｓｃｅｎｃｅ）のフレキシブルディスプレイ用の材料のいずれかからなり、透明基板２１０の周囲に形成される。 The transparent substrate 210 is made of a film or glass. The transparent conductive film 220 is made of any material for flexible displays such as ITO (Indium Tin Oxide), SnO 2 , ZnO, and organic EL (Electro Luminescence), and is formed around the transparent substrate 210.
　導電性高分子２３０は、ポリアセチレン、ポリパラフェニレン、ポリアニリン、ポリチオフェンおよびポリパラフェニレンビニレンのいずれかからなる。そして、導電性高分子２３０は、透明導電膜２２０および発光部材２４０に接して透明導電膜２２０と発光部材２４０との間に配置される。 The conductive polymer 230 is made of any one of polyacetylene, polyparaphenylene, polyaniline, polythiophene, and polyparaphenylene vinylene. The conductive polymer 230 is disposed between the transparent conductive film 220 and the light emitting member 240 in contact with the transparent conductive film 220 and the light emitting member 240.
　なお、キャリア移動度を大きくし、電極に印加された電圧を有効利用するためには、導電性高分子２３０は、比誘電率の小さい材料からなる。 In order to increase the carrier mobility and effectively use the voltage applied to the electrode, the conductive polymer 230 is made of a material having a low relative dielectric constant.
　発光部材２４０は、積層された複数の発光粉体１０からなる。そして、発光部材２４０は、導電性高分子２３０および電極２５０に接して導電性高分子２３０と電極２５０との間に配置される。 The light emitting member 240 is composed of a plurality of laminated light emitting powders 10. The light emitting member 240 is disposed between the conductive polymer 230 and the electrode 250 in contact with the conductive polymer 230 and the electrode 250.
　電極２５０は、たとえば、金（Ａｕ）からなり、発光部材２４０に接して発光部材２４０上に形成される。また、電極２５０は、合金材料（Ｃａ／Ａｇ）およびＭｇ系の金属からなっていてもよく、ナノ金属の集積体からなっていてもよい。 The electrode 250 is made of, for example, gold (Au), and is formed on the light emitting member 240 in contact with the light emitting member 240. Further, the electrode 250 may be made of an alloy material (Ca / Ag) and an Mg-based metal, or may be made of a nano metal aggregate.
　発光素子２００において、電圧が透明導電膜２２０と電極２５０との間に印加されると、電子および正孔が発光部材２４０の発光粉体１０に注入され、発光部材２４０が発光する。この場合、電子および正孔は、発光粉体１０の約２ｎｍの厚みを有する酸化シリコン（ＳｉＯ２）２をトンネルして結晶シリコン１中へ注入される。また、２つの発光粉体１０が接する領域においては、電子および正孔は、発光粉体１０の約２ｎｍの厚みを有する酸化シリコン（ＳｉＯ２）２をトンネルして一方の発光粉体１０から他方の発光粉体１０へ流れる。したがって、発光粉体１０が積層されていても、その積層された発光粉体１０に電子および正孔を注入できる。 In the light emitting element 200, when a voltage is applied between the transparent conductive film 220 and the electrode 250, electrons and holes are injected into the light emitting powder 10 of the light emitting member 240 and the light emitting member 240 emits light. In this case, electrons and holes are injected into the crystalline silicon 1 through the silicon oxide (SiO 2 ) 2 having a thickness of about 2 nm of the luminescent powder 10. Further, in the region where the two luminescent powders 10 are in contact, electrons and holes tunnel through the silicon oxide (SiO 2 ) 2 having a thickness of about 2 nm of the luminescent powder 10 and from one luminescent powder 10 to the other. The luminescent powder 10 flows. Therefore, even if the luminescent powder 10 is laminated, electrons and holes can be injected into the laminated luminescent powder 10.
　また、発光素子２００は、３．８２Ｖの電圧が透明導電膜２２０と電極２５０との間に印加されると、白色で発光し、３．３Ｖの電圧が透明導電膜２２０と電極２５０との間に印加されると、青色で発光し、２．７Ｖの電圧が透明導電膜２２０と電極２５０との間に印加されると、緑色で発光し、２．４１Ｖの電圧が透明導電膜２２０と電極２５０との間に印加されると、赤色で発光する。 The light emitting element 200 emits white light when a voltage of 3.82 V is applied between the transparent conductive film 220 and the electrode 250, and a voltage of 3.3 V is generated between the transparent conductive film 220 and the electrode 250. When the voltage is applied to the transparent conductive film 220, the light is emitted in blue, and when a voltage of 2.7 V is applied between the transparent conductive film 220 and the electrode 250, the light is emitted in green, and a voltage of 2.41 V is applied to the transparent conductive film 220 and the electrode. When it is applied to 250, it emits red light.
　なお、これらの電圧値は、最小の電圧値であり、結晶シリコン１と酸化シリコン２との界面におけるエネルギーギャップが作用する場合には、高電圧側へシフトする。 Note that these voltage values are minimum voltage values, and shift to the high voltage side when the energy gap at the interface between the crystalline silicon 1 and the silicon oxide 2 acts.
　このように、透明導電膜２２０と電極２５０との間に印加する電圧を制御することによって発光素子２００を異なる色で発光させることができる。 Thus, by controlling the voltage applied between the transparent conductive film 220 and the electrode 250, the light emitting element 200 can emit light in different colors.
　図１４は、図１３に示す発光素子２００の製造方法を示す工程図である。図１４を参照して、発光素子２００の製造が開始されると、複数の発光粉体１０が図３に示す工程に従って製造される（ステップＳ１１）。 FIG. 14 is a process diagram showing a method of manufacturing the light emitting device 200 shown in FIG. Referring to FIG. 14, when the manufacture of light emitting element 200 is started, a plurality of light emitting powders 10 are manufactured according to the process shown in FIG. 3 (step S11).
　そして、複数の発光粉体１０を収集して複数の発光粉体１０からなる発光部材２４０が製造される（ステップＳ１２）。 Then, a plurality of luminescent powders 10 are collected and a light emitting member 240 made of the plurality of luminescent powders 10 is manufactured (step S12).
　引き続いて、発光部材２４０が導電性高分子２３０によって透明導電膜２２０に接着される（ステップＳ１３）。 Subsequently, the light emitting member 240 is bonded to the transparent conductive film 220 by the conductive polymer 230 (step S13).
　そして、電極２５０がスパッタリング、蒸着、およびインクジェット法のいずれかによって発光部材２４０上に形成される（ステップＳ１４）。これによって、発光素子２００が完成する。 Then, the electrode 250 is formed on the light emitting member 240 by any of sputtering, vapor deposition, and ink jet method (step S14). Thereby, the light emitting element 200 is completed.
　なお、発光素子２００においては、電極２５０は、ＩＴＯ等の透明導電膜からなっていてもよい。 In the light emitting element 200, the electrode 250 may be made of a transparent conductive film such as ITO.
　また、発光素子２００は、透明基板２１０および透明導電膜２２０に代えて、キャリア濃度が１０２０ｃｍ－３以上のｎ型またはｐ型のシリコンウェハを備えていてもよく、透明基板２１０および透明導電膜２２０に代えて、キャリア濃度が１０２０ｃｍ－３以上のｎ型またはｐ型のシリコンウェハを備え、かつ、電極２５０に代えて、キャリア濃度が１０２０ｃｍ－３以上のｐｎ型またはｎ型のシリコンウェハを備えていてもよい。この場合、発光した光は、発光素子２００の横方向へ出射される。 The light emitting element 200 may include an n-type or p-type silicon wafer having a carrier concentration of 10 20 cm −3 or more instead of the transparent substrate 210 and the transparent conductive film 220. instead of the membrane 220, the carrier concentration with a is 10 20 cm -3 or more n-type or p-type silicon wafer, and, in place of the electrode 250, the carrier concentration is 10 20 cm -3 or more pn-type or n-type The silicon wafer may be provided. In this case, the emitted light is emitted in the lateral direction of the light emitting element 200.
　図１５は、この発明の実施の形態による他の発光素子の構成を示す断面図である。この発明の実施の形態による発光素子は、図１５に示す発光素子２００Ａであってもよい。 FIG. 15 is a cross-sectional view showing the configuration of another light emitting device according to the embodiment of the present invention. The light emitting device according to the embodiment of the present invention may be a light emitting device 200A shown in FIG.
　図１５を参照して、発光素子２００Ａは、図１３に示す発光素子２００の電極２５０を電極２６０に代えたものであり、その他は、発光素子２００と同じである。 Referring to FIG. 15, a light emitting element 200A is the same as light emitting element 200 except that electrode 250 of light emitting element 200 shown in FIG.
　電極２６０は、たとえば、Ａｕからなり、発光部材２４０に接して発光部材２４０上に形成される。 The electrode 260 is made of, for example, Au, and is formed on the light emitting member 240 in contact with the light emitting member 240.
　図１６は、図１５に示すＢ方向から見た電極２６０の平面図である。図１６を参照して、電極２６０は、電極片２６１～２６４からなる。 FIG. 16 is a plan view of the electrode 260 viewed from the direction B shown in FIG. Referring to FIG. 16, electrode 260 includes electrode pieces 261-264.
　電極片２６１～２６４は、相互に異なる電圧が印加される。たとえば、電極片２６１は、３．８２Ｖの電圧が印加され、電極片２６２は、３．３Ｖの電圧が印加され、電極片２６３は、２．７Ｖの電圧が印加され、電極片２６４は、２．４１Ｖの電圧が印加される。 Different voltages are applied to the electrode pieces 261 to 264. For example, a voltage of 3.82 V is applied to the electrode piece 261, a voltage of 3.3 V is applied to the electrode piece 262, a voltage of 2.7 V is applied to the electrode piece 263, and the voltage of the electrode piece 264 is 2 A voltage of .41V is applied.
　その結果、電極片２６１に接する発光部材２４０の領域は、白色で発光し、電極片２６２に接する発光部材２４０の領域は、青色で発光し、電極片２６３に接する発光部材２４０の領域は、緑色で発光し、電極片２６４に接する発光部材２４０の領域は、赤色で発光する。 As a result, the region of the light emitting member 240 in contact with the electrode piece 261 emits white light, the region of the light emitting member 240 in contact with the electrode piece 262 emits blue light, and the region of the light emitting member 240 in contact with the electrode piece 263 is green. The region of the light emitting member 240 that emits light and contacts the electrode piece 264 emits red light.
　このように、発光素子２００Ａは、白色の光、青色の光、緑色の光および赤色の光を同時に発光する発光素子である。 Thus, the light emitting element 200A is a light emitting element that simultaneously emits white light, blue light, green light, and red light.
　なお、発光素子２００Ａは、図１４に示すステップＳ１４の後に、電極２６０をフォトリソグラフィによって電極片２６１～２６４にパターンニングするステップを追加する工程に従って製造される。 The light emitting element 200A is manufactured according to a process of adding a step of patterning the electrode 260 into electrode pieces 261 to 264 by photolithography after step S14 shown in FIG.
　また、発光素子２００Ａにおいては、電極２５０は、ＩＴＯ等の透明導電膜からなっていてもよい。 Further, in the light emitting element 200A, the electrode 250 may be made of a transparent conductive film such as ITO.
　さらに、発光素子２００Ａは、透明基板２１０および透明導電膜２２０に代えて、キャリア濃度が１０２０ｃｍ－３以上のｎ型またはｐ型のシリコンウェハを備えていてもよい。この場合、発光した光は、発光素子２００Ａの横方向へ出射される。 Further, the light emitting element 200A may include an n-type or p-type silicon wafer having a carrier concentration of 10 20 cm −3 or more, instead of the transparent substrate 210 and the transparent conductive film 220. In this case, the emitted light is emitted in the lateral direction of the light emitting element 200A.
　さらに、発光素子２００Ａにおいては、透明導電膜２２０が電極２６０と同じようにパターンニングされていてもよい。そして、一般的には、発光素子２００Ａにおいては、発光部材２４０の両側に配置される２つの電極のうち、少なくとも一方が複数の電極片にパターンニングされていればよい。 Furthermore, in the light emitting element 200A, the transparent conductive film 220 may be patterned in the same manner as the electrode 260. In general, in the light emitting element 200A, at least one of the two electrodes disposed on both sides of the light emitting member 240 may be patterned into a plurality of electrode pieces.
　そして、上述した発光素子２００，２００Ａは、照明装置および表示装置に適用される。シリコンナノ材料の発光寿命は、そのサイズを考慮すると、マイクロ秒オーダー（場合によっては、ナノ秒またはピコ秒のオーダー）であると想定される。したがって、スイッチング回路を用いることにより、発光／点滅が素早くなり、電気追従性がよい。その結果、発光素子２００，２００Ａは、液晶表示装置に比べ、動画用のディスプレイに適している。 The light emitting elements 200 and 200A described above are applied to lighting devices and display devices. The luminescence lifetime of silicon nanomaterials is assumed to be on the order of microseconds (in some cases on the order of nanoseconds or picoseconds), considering its size. Therefore, by using the switching circuit, the light emission / flashing becomes quick and the electric follow-up property is good. As a result, the light emitting elements 200 and 200A are more suitable for a moving image display than a liquid crystal display device.
　また、発光粉体１０は、フォトルミネッセンス（ＰＬ）用の素子に適用できる。従来の蛍光灯は、水銀が封入され、その封入された水銀の紫外線によってユーロビウム（Ｅｕ）およびテルビウム（Ｔｂ）等の希土類元素を励起し、三原色の光を混ぜて白色蛍光灯としている。そこで、上述した発光粉体１０を蛍光灯に用いると、希土類元素の代用になるとともに、紫外線照射によって白色蛍光灯を実現できる。また、発光粉体１０は、プラズマディスプレイにも適用可能である。 Further, the luminescent powder 10 can be applied to an element for photoluminescence (PL). In the conventional fluorescent lamp, mercury is enclosed, and rare earth elements such as eurobium (Eu) and terbium (Tb) are excited by ultraviolet light of the enclosed mercury, and light of three primary colors is mixed to form a white fluorescent lamp. Therefore, when the above-described luminescent powder 10 is used in a fluorescent lamp, it can be used as a substitute for rare earth elements and a white fluorescent lamp can be realized by ultraviolet irradiation. The luminescent powder 10 can also be applied to a plasma display.
　素子構造は、発光粉体１０を紫外透過性高分子に溶媒と一緒に混ぜ、その溶液をガラス内壁に塗布し、その後、溶媒を飛ばすことによって、発光粉体１０を紫外透過性高分子と一緒にガラス表面に固化させた構造である。そして、固化させるガラスは、透明な材料であればどのような材料であってもよく、また、形状も、平面および曲面のいずれでもよい。そして、内側から水銀の放電または希ガスの放電によって発光させる。 In the device structure, the luminescent powder 10 is mixed with the ultraviolet transmissive polymer by mixing the luminescent powder 10 with the ultraviolet transmissive polymer together with the solvent, coating the solution on the inner wall of the glass, and then removing the solvent. The structure is solidified on the glass surface. The glass to be solidified may be any material as long as it is a transparent material, and the shape may be either a flat surface or a curved surface. Then, light is emitted from the inside by mercury discharge or rare gas discharge.
　上記においては、反応容器２５は、シリコン塊４０を保持すると説明したが、この発明の実施の形態においては、反応容器２５は、シリコンウェハを保持してもよい。この場合、シリコンウェハは、その表面がレーザ光に対して略垂直になるように反応容器２５内に保持される。 In the above description, it has been described that the reaction vessel 25 holds the silicon lump 40. However, in the embodiment of the present invention, the reaction vessel 25 may hold a silicon wafer. In this case, the silicon wafer is held in the reaction vessel 25 so that the surface thereof is substantially perpendicular to the laser beam.
　また、この発明の実施の形態においては、ポンプ２２、冷却器２４、ヒータ２８、熱電対２９、温度検出器３０および制御器３１は、反応容器２５内にＣＯ２からなる超臨界流体を生成する「生成器」を構成する。 In the embodiment of the present invention, the pump 22, the cooler 24, the heater 28, the thermocouple 29, the temperature detector 30 and the controller 31 generate a supercritical fluid made of CO 2 in the reaction vessel 25. Configure the “generator”.
　今回開示された実施の形態はすべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は、上記した実施の形態の説明ではなくて特許請求の範囲によって示され、特許請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。 The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.
　この発明は、白色で発光可能な発光粉体に適用される。また、この発明は、白色で発光可能な発光粉体の製造方法に適用される。さらに、この発明は、白色で発光可能な発光粉体を用いた発光素子に適用される。さらに、この発明は、白色で発光可能な発光粉体を用いた発光素子の製造方法に適用される。さらに、この発明は、白色で発光可能な発光粉体の製造装置に適用される。 The present invention is applied to a luminescent powder capable of emitting white light. The present invention is also applied to a method for producing a luminescent powder capable of emitting white light. Furthermore, the present invention is applied to a light emitting element using a luminescent powder capable of emitting white light. Furthermore, the present invention is applied to a method for manufacturing a light-emitting element using a luminescent powder capable of emitting white light. Further, the present invention is applied to an apparatus for producing a luminescent powder capable of emitting white light.

Claims (12)

  1. 　二酸化炭素からなる超臨界流体中に単結晶シリコン（４０）を保持する第１の工程と、
    　ナノサイズの結晶シリコン（１）が前記単結晶シリコン（４０）から前記超臨界流体中へ飛び出すレーザアブレーションが生じる強度を有するレーザ光を前記単結晶シリコン（４０）に照射する第２の工程とを実行して製造される発光粉体。     A first step of holding single crystal silicon (40) in a supercritical fluid comprising carbon dioxide;
    A second step of irradiating the single crystal silicon (40) with a laser beam having an intensity that causes laser ablation in which the nano-sized crystal silicon (1) jumps out of the single crystal silicon (40) into the supercritical fluid; Luminescent powder produced by execution.
  2. 　前記超臨界流体中へ飛び出した前記ナノサイズの結晶シリコン（１）を前記超臨界流体の圧力によって決定された成長時間だけ成長させる第３の工程をさらに実行して製造される、請求項１に記載の発光粉体。 2. The method according to claim 1, further comprising performing a third step of growing the nano-sized crystalline silicon (1) jumping into the supercritical fluid for a growth time determined by the pressure of the supercritical fluid. The luminescent powder described.
  3. 　前記第３の工程において、前記ナノサイズの結晶シリコン（１）は、前記超臨界流体の圧力が高い程、長い時間、成長し、前記超臨界流体の圧力が低い程、短い時間、成長する、請求項２に記載の発光粉体。 In the third step, the nano-sized crystalline silicon (1) grows for a longer time as the pressure of the supercritical fluid is higher, and grows for a shorter time as the pressure of the supercritical fluid is lower. The luminescent powder according to claim 2.
  4. 　二酸化炭素からなる超臨界流体中に単結晶シリコン（４０）を保持する第１の工程と、
    　ナノサイズの結晶シリコン（１）が前記単結晶シリコン（４０）から前記超臨界流体中へ飛び出すレーザアブレーションが生じる強度を有するレーザ光を前記単結晶シリコン（４０）に照射する第２の工程とを備える発光粉体の製造方法。     A first step of holding single crystal silicon (40) in a supercritical fluid comprising carbon dioxide;
    A second step of irradiating the single crystal silicon (40) with a laser beam having an intensity that causes laser ablation in which the nano-sized crystal silicon (1) jumps out of the single crystal silicon (40) into the supercritical fluid; A method for producing a luminescent powder.
  5. 　前記超臨界流体中へ飛び出した前記ナノサイズの結晶シリコン（１）を前記超臨界流体の圧力によって決定された成長時間だけ成長させる第３の工程をさらに備える、請求項４に記載の発光粉体の製造方法。 The luminescent powder according to claim 4, further comprising a third step of growing the nano-sized crystalline silicon (1) jumping into the supercritical fluid for a growth time determined by the pressure of the supercritical fluid. Manufacturing method.
  6. 　前記第３の工程において、前記ナノサイズの結晶シリコン（１）は、前記超臨界流体の圧力が高い程、長い時間、成長し、前記超臨界流体の圧力が低い程、短い時間、成長する、請求項５に記載の発光粉体の製造方法。 In the third step, the nano-sized crystalline silicon (1) grows for a longer time as the pressure of the supercritical fluid is higher, and grows for a shorter time as the pressure of the supercritical fluid is lower. The method for producing a luminescent powder according to claim 5.
  7. 　前記第１の工程は、
    　前記単結晶シリコン（４０）を反応容器（２５）内に入れる第１のサブ工程と、
    　前記二酸化炭素をサイフォン式のボンベから取り出し、耐膨潤性のある材料によってシールされた圧力弁（２０１）、潤滑材を取り除いて作製されたポンプ（２０）、およびオイルフリーの配管（２１，２３）を用いて前記超臨界流体が生成される圧力になるように前記反応容器（２５）に前記取り出した二酸化炭素を供給する第２のサブ工程と、
    　前記超臨界流体が生成される温度になるように前記反応容器（２５）を加熱する第３のサブ工程とを含む、請求項４に記載の発光粉体の製造方法。     The first step includes
    A first sub-step of placing said single crystal silicon (40) into a reaction vessel (25);
    The carbon dioxide is taken out of the siphon type cylinder, the pressure valve (201) sealed with a material having swelling resistance, the pump (20) prepared by removing the lubricant, and the oil-free pipes (21, 23) A second sub-step of supplying the extracted carbon dioxide to the reaction vessel (25) so that the pressure at which the supercritical fluid is generated using
    The method for producing a luminescent powder according to claim 4, further comprising a third sub-step of heating the reaction vessel (25) so as to reach a temperature at which the supercritical fluid is generated.
  8. 　発光部材（２４０）と、
    　前記発光部材（２４０）の一方の表面に形成された第１の電極（２２０）と、
    　前記発光部材（２４０）の他方の表面に形成された第２の電極（２５０）とを備え、
    　前記発光部材（２４０）は、複数の発光粉体（１０）からなり、
    　前記複数の発光粉体（１０）の各々は、請求項１から請求項３のいずれか１項に記載の発光粉体からなる、発光素子。     A light emitting member (240);
    A first electrode (220) formed on one surface of the light emitting member (240);
    A second electrode (250) formed on the other surface of the light emitting member (240),
    The light emitting member (240) is composed of a plurality of light emitting powders (10),
    Each of these light emitting powders (10) is a light emitting element which consists of luminescent powder of any one of Claims 1-3.
  9. 　前記第１および第２の電極の少なくとも一方の電極は、透明導電膜からなる、請求項８に記載の発光素子。 The light emitting device according to claim 8, wherein at least one of the first and second electrodes is made of a transparent conductive film.
  10. 　前記第１および第２の電極の少なくとも一方の電極は、複数の電極片（２６１～２６４）からなる、請求項８に記載の発光素子。 The light emitting device according to claim 8, wherein at least one of the first and second electrodes is composed of a plurality of electrode pieces (261 to 264).
  11. 　複数の発光粉体（１０）を製造する第１の工程と、
    　前記複数の発光粉体（１０）を収集して前記複数の発光粉体（１０）からなる発光部材（２４０）を製造する第２の工程と、
    　基板（２１０）上に形成された第１の電極（２２０）に前記発光部材（２４０）を接着する第３の工程と、
    　前記発光部材（２４０）上に第２の電極（２５０）を形成する第４の工程とを備え、
    　前記第１の工程は、
    　二酸化炭素からなる超臨界流体中に単結晶シリコン（４０）を保持する第１のサブ工程と、
    　ナノサイズの結晶シリコン（１）が前記単結晶シリコン（４０）から前記超臨界流体中へ飛び出すレーザアブレーションが生じる強度を有するレーザ光を前記単結晶シリコン（４０）に照射する第２のサブ工程とを含む、発光素子の製造方法。     A first step of producing a plurality of luminescent powders (10);
    A second step of collecting the plurality of luminescent powders (10) to produce a light emitting member (240) comprising the plurality of luminescent powders (10);
    A third step of bonding the light emitting member (240) to the first electrode (220) formed on the substrate (210);
    And a fourth step of forming a second electrode (250) on the light emitting member (240),
    The first step includes
    A first sub-step of holding single crystal silicon (40) in a supercritical fluid consisting of carbon dioxide;
    A second sub-step of irradiating the single crystal silicon (40) with a laser beam having an intensity that causes laser ablation in which nano-sized crystal silicon (1) jumps out of the single crystal silicon (40) into the supercritical fluid; A method for manufacturing a light emitting device, comprising:
  12. 　単結晶シリコン（４０）を保持する反応容器（２５）と、
    　前記反応容器（２５）に液体の二酸化炭素を供給し、前記反応容器（２５）内に前記二酸化炭素からなる超臨界流体を生成する生成器（２２，２４，２８，２９，３０，３１）と、
    　ナノサイズの結晶シリコン（１）が前記単結晶シリコン（４０）から前記超臨界流体中へ飛び出すレーザアブレーションが生じる強度を有するレーザ光を前記単結晶シリコン（４０）に照射するレーザ装置（２６）とを備える発光粉体の製造装置。     A reaction vessel (25) holding single crystal silicon (40);
    A generator (22, 24, 28, 29, 30, 31) for supplying liquid carbon dioxide to the reaction vessel (25) and generating a supercritical fluid composed of the carbon dioxide in the reaction vessel (25); ,
    A laser device (26) for irradiating the single crystal silicon (40) with laser light having an intensity that causes laser ablation in which nano-sized crystalline silicon (1) jumps out of the single crystal silicon (40) into the supercritical fluid; A luminescent powder production apparatus comprising:
PCT/JP2009/002596 2009-06-09 2009-06-09 Luminescent powder, method for producing same, luminescent element wherein luminescent powder is used, method for producing said luminescent element, and apparatus for producing luminescent powder WO2010143225A1 (en)

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Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
K.SAITOW: "Gold Nanospheres and Nanonecklaces Generated by Laser Ablation in Supercritical Fluid", THE JOURNAL OF PHYSICAL CHEMISTRY C, vol. 112, 2008, pages 18340 - 18349 *
K.SAITOW: "Silicon Nanoclusters Selectively Generated by Laser Ablation in Supercritical Fluid", THE JOURNAL OF PHYSICAL CHEMISTRY B, vol. 109, 2005, pages 3731 - 3733 *
KEISUKE SATO: "Kashi Hakko Kino o Fuka shita Nano Silicon Ryushi no Seizoho to sono Oyo", ELECTRONIC MATERIALS AND PARTS, vol. 47, no. 11, 2008, pages 81 - 85 *
TOMOHARU YAMAMURA: "Cho Rinkai Ryutaichu deno Tankessho Silicon no Pulse Laser Shosha ni yori Sosei shita Midori.Aka Iro Hakko Silicon Nano Kessho", CSJ: THE CHEMICAL SOCIETY OF JAPAN KOEN YOKOSHU, vol. 88, no. 1, 2008, pages 429 *

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