JP2006077124A - Silicon nanoparticle fluorescent substance - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a Si (silicon) nanoparticle fluorescent substance comprising Si nanoparticles of which the surfaces have hydrocarbon groups and which have a particle diameter of 1-5 nm, and to provide a method for producing the Si nanoparticle fluorescent substance, capable of controlling a particle size of the substance. <P>SOLUTION: This Si nanoparticle fluorescent substance of which the surface is combined with the hydrocarbon groups each expressed by R (R is a 1-18C alkyl, a 1-18C alkenyl, a 1-18C alkynyl, a 3-7C cycloalkyl, a 3-7C cycloalkyl-1-12C alkyl, a 6-14C aryl, a 6-10C aryl-1-12C alkyl, a 1-18C ether or a 1-18C ester) and which has the particle diameter of 1-5 nm is produced by the method for producing the substance which comprises reacting a powder of an alloy expressed by Mg<SB>2</SB>Si with silicon tetrachloride (SiCl<SB>4</SB>) in a reaction solvent, and then reacting the obtained Si compound with an alkylating agent expressed by RMgX (X is a halogen) or RLi. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a phosphor of quantum-size nanocrystalline silicon (nc-Si) (nano-sized silicon particles) and a method for producing the same.

Nanocrystalline silicon (nc-Si) is used for EL elements (electroluminescence elements) and ultrasonic elements, but is not used as a phosphor. As nano-sized phosphors, only visible light emission by nano-particle phosphors of group II-VI ZnS and CdSe is known. However, since these phosphors are harmful to the natural environment and it is difficult to separate and extract these elements, the phosphors cannot be manufactured at low cost. Under such circumstances, a method for producing nanometer-sized silicon particles is known (Non-Patent Document 1).
However, such Si (silicon) nanoparticles can only obtain a PL spectrum (emission) having a peak at 350 nm by excitation with ultraviolet light, and the phosphor is not good in luminous efficiency. It was poor in practicality. Further, the particle size and the emission wavelength cannot be controlled.
J. Am. Chem. Soc. 199, 121, 5191-5195

  An object of the present invention is to provide a silicon nanoparticle phosphor having a particle size of 1 to 5 nm having a hydrocarbon group on the particle surface and a method for producing the silicon nanoparticle phosphor capable of controlling the particle size.

Therefore, the present inventors have intensively studied to provide a phosphor of Si (silicon) nanoparticles, and when a hydrocarbon group is bonded to the surface of a silicon particle having a particle size of 1 to 5 nm, for example, by ultraviolet excitation. The present inventors have found that it is possible to emit visible light, adjust the particle size according to the reaction conditions of Mg ₂ Si and SiCl ₄ (silicon tetrachloride) and control the emission color.

The present invention provides a hydrocarbon group represented by R (R is C _1-18 alkyl, C _1-18 alkenyl, C _1-18 alkynyl, C _3-7 cycloalkyl) on the surface of silicon particles having a particle size of 1 to 5 nm. , C _3-7 cycloalkyl-C _1-12 alkyl, C _6-14 aryl, C _6-10 aryl-C _1-12 alkyl, C _1-18 ether or C _1-18 ester), It exists in the silicon nanoparticle fluorescent substance characterized by the emission wavelength after excitation being in a visible region.
The present invention is silicon nanoparticles in which Si atoms are bonded in a three-dimensional network. On the surface of the silicon nanoparticle, a plurality of hydrocarbon groups are bonded to respective Si atoms in the silicon nanoparticle, and the surface is covered with the hydrocarbon group, thereby preventing oxidation of the silicon nanoparticle. it can. As a result, the emission wavelength and emission efficiency of the silicon nanoparticles can be prevented from decreasing. Further, by adjusting the particle size, the emission wavelength after excitation can be made visible.

  The excitation may be performed by light irradiation, particularly ultraviolet irradiation of 400 nm or less or current injection.

The phosphor is
(1) a first step of reacting an alloy powder represented by Mg ₂ Si with silicon tetrachloride (SiCl ₄ ) in a reaction solvent;
(2) The obtained silicon compound and formula: RMgX or RLi (wherein R is C _1-18 alkyl, C _1-18 alkenyl, C _1-18 alkynyl, C _3-7 cycloalkyl, C _3-7 cyclo) Alkyl-C _1-12 alkyl, C _6-14 aryl, C _6-10 aryl-C _1-12 alkyl C _1-18 ether or C _1-18 ester, wherein X represents a halogen atom. Comprising a second step of reacting with an alkylating agent,
(3) A silicon nanoparticle phosphor having a particle diameter of 1 to 5 nm, on which the hydrocarbon group represented by R is bonded to the surface, can be produced by a method for producing silicon nanoparticles. .
According to the method for producing silicon nanoparticles of the present invention, silicon nanoparticles in which Si atoms are bonded in a three-dimensional network form, on the surface of the silicon nanoparticles, a plurality of hydrocarbon groups are respectively present in the silicon nanoparticles. Thus, silicon nanoparticles that are bonded to Si atoms and whose surfaces are covered with hydrocarbon groups can be obtained. The surface of the silicon nanoparticle is covered with a hydrocarbon group, so that the oxidation of the silicon nanoparticle can be prevented, thereby preventing the emission wavelength and the luminous efficiency of the silicon nanoparticle from being lowered. .
Furthermore, since the particle size of silicon nanoparticles and the emission wavelength after excitation are related, if the particle size is adjusted, the emission wavelength after excitation of the silicon nanoparticles can be made visible.

  In the production method according to the present invention, the first step is performed in a reaction solvent in an argon gas atmosphere at a reaction temperature of 0 ° C. to 150 ° C. and a pressure of normal pressure (10135 Pa) to 10 MPa for 1 day to 10 days. Is preferred.

In the first step, the silicon tetrachloride (SiCl ₄ ) is preferably used in a weight ratio of 1: 1 to 1:10 with respect to the alloy powder represented by Mg ₂ Si. The weight ratio of silicon tetrachloride for Mg ₂ Si alloy (SiCl ₄₎ 1: to greater than 1 is because _{the Mg} 2 Si alloy powder is left in the reaction solution, 1: to less than 10 This is because it takes time to remove unreacted silicon tetrachloride (SiCl ₄ ) that did not react in the first step.

Furthermore, in the first step, the ratio of the volume (l) of the reaction solvent to the weight (g) of the alloy powder represented by Mg ₂ Si is 1: 0.1 to 1: 1. preferable. The ratio of the volume (l) of the reaction solvent to the weight (g) of the Mg ₂ Si alloy is larger than 1: 0.1 because it takes time to remove the solvent in the post-treatment at the end of the first step. It is.

  Furthermore, the reaction solvent is diglyme, triglyme, dioxane, methyl isobutyl ketone (MIBK), tetrahydrofuran (THF), methyl t-butyl ether (MTBE), polyethylene glycol (PEG), toluene, xylene. It is preferable to use at least one solvent selected from the group consisting of nitrobenzene, n-heptane, n-hexane, chloroform, methylene chloride, diethyl ether, and petroleum ether.

The present invention also resides in a silicon nanoparticle phosphor in which the hydrocarbon group represented by R of the phosphor particle has a reactive group Y for use as a biotag. Here, the biotag is a functional substance composed of two parts, a label part and a binding part. The biotag is bound to the biological substance by the binding portion, and its presence can be observed by the characteristic property of the labeling portion. The biotag enables observation of the dynamic behavior of biological material in living organisms inside and outside the body and quantification of the amount produced. The silicon nanoparticle phosphor corresponds to a labeling portion.
Biotags using fluorescent materials are widely used as research and development in medicine, chemistry, agriculture, etc., and as diagnostic kits in the medical field. However, organic compounds and organometallic complexes have been used in conventional fluorescent materials, and there is a concern that the stability of the labeling site is relatively low. Many of these substances are also suspected of being harmful to the human body.
In general, when the emission wavelength width of the phosphor is wide, the function as the phosphor is regarded as a problem. Therefore, development of a substance exhibiting a sharper emission spectrum is desired.
The silicon nanoparticle phosphor according to the present invention can solve the problems of high stability, low toxicity, sharp emission wavelength, and many fluorescent substances.
The reactive group Y is a part capable of binding to the living body, and the reactive group is bonded to the silicon nanoparticle via the R group. Can be combined.

  As the bonding part, at the terminal of the R group, an alkyl halide, hydroxyl group, amino group, carboxylic acid, isothiocyanate, silicon halide, boronic acid, succinimide ester, sulfonyl halide, mercaptan, or hydrazine which is a reactive group Are combined.

  According to the silicon nanoparticle phosphor of the present invention, it is possible to provide a fluorescent material that emits light stably in the visible wavelength region and can control the emission wavelength. This phosphor can be applied to display devices, biotags, and the like, and can be used as a fluorescent material with no environmental load.

(Method for producing silicon nanoparticle phosphor)
[First reaction step]
An alloy powder represented by Mg ₂ Si and excess silicon tetrachloride (SiCl ₄ ) are reacted in a solvent under an argon atmosphere. Here, reaction temperature is 0-150 degreeC, More preferably, it is 20-100 degreeC, More preferably, it is 30-80 degreeC. The reaction time is 1 to 10 days, more preferably 3 to 7 days. The reaction pressure is normal pressure (10135 Pa) to 10 MPa, more preferably 3 MPa to 6 MPa. Examples of the solvent include diglyme, triglyme, dioxane, methyl isobutyl ketone (MIBK), tetrahydrofuran (THF), methyl t-butyl ether (MTBE), polyethylene glycol (PEG), toluene, xylene, and nitrobenzene. , N-heptane, n-hexane, chloroform, methylene chloride, diethyl ether, petroleum ether, and the like. These solvents may be used alone or in admixture of two or more. Tetrahydrofuran (THF) is preferable.

Next, the solution produced in the first reaction step is concentrated under reduced pressure in an argon atmosphere, and the reaction solvent and unreacted silicon tetrachloride (SiCl ₄ ) are removed. A spherical cluster is formed, and silicon particles in which Cl atoms are bonded to Si atoms around the sphere can be obtained.

[Second reaction step]
Subsequently, the silicon compound and the formula: RMgX or RLi (wherein R is C _1-18 alkyl, C _1-18 alkenyl, C _1-18 alkynyl, C _3-7 cycloalkyl, C _3-7 cycloalkyl- C _1-12 alkyl, C _6-14 aryl, C _6-10 aryl-C _1-12 alkyl, C _1-18 ether or C _1-18 ester, X represents a halogen atom) The agent is reacted in a solvent. As the solvent, the solvents used in the first reaction step, that is, diglyme, triglyme, dioxane, methyl isobutyl ketone (MIBK), tetrahydrofuran (THF), methyl t-butyl ether (MTBE), polyethylene glycol A solvent comprising at least one selected from (PEG), toluene, xylene, nitrobenzene, n-heptane, n-hexane, chloroform, methylene chloride, diethyl ether, and petroleum ether can be used. The solvent used in the second reaction step may be the same as or different from the solvent used in the first reaction step.

Examples of the C _1-18 alkyl group represented by R of the alkylating agent include, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group. Group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecane group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group and octadecyl group.

Examples of the C _1-18 alkenyl group include a vinyl group, an allyl group, a crotyl group, a 2-pentenyl group, and a 3-hexenyl group. Examples of the C _1-18 alkynyl group include an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 1-butynyl group, a 2-pentynyl group, and a 3-hexynyl group. Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group.

Furthermore, as C _3-7 cycloalkyl-C _1-12 alkyl, for example, at least one bond of a functional group selected from a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group, Methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl Substituted with a functional group selected from a group, undecyl group, dodecane group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, and conversely, for example, methyl group, ethyl group, propyl group, isopropyl Group, butyl group, isobutyl group, sec-butyl group, tert-butyl Group, pentyl group, isopentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecane group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group Examples thereof include those in which at least one bond of a selected functional group is substituted with at least one functional group selected from a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group.

Examples of the C _6-14 aryl group include a phenyl group and a naphthyl group.

As C _6-10 aryl-C _1-12 alkyl, for example, at least one bond of a functional group selected from a phenyl group and a naphthyl group is selected from, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, Isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecane, tridecyl, tetradecyl, pentadecyl Substituted with at least one functional group selected from a group, hexadecyl group, heptadecyl group, octadecyl group, conversely, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl , An octyl group, a nonyl group, a decyl group, an undecyl group, a dodecane group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, and at least one bond thereof, for example, a phenyl group And those substituted with at least one functional group selected from naphthyl groups.

As C _1-18 ether, each of R ₁ and R ₂ of R ₁ —O—R ₂ is, for example, C _1-18 alkyl, C _1-18 alkenyl, C _1-18 alkynyl, C _3-7 cycloalkyl. , C _3-7 cycloalkyl-C _1-12 alkyl, C _6-14 aryl, C _6-10 aryl-C _1-12 alkyl, C _1-18 ether or C _1-18 ester Can be mentioned. Where C _1-18 alkyl, C _1-18 alkenyl, C _1-18 alkynyl, C _3-7 cycloalkyl, C _3-7 cycloalkyl-C _1-12 alkyl, C _6-14 aryl, C _{6-6 10} aryl-C _1-12 alkyl, C _1-18 ether or C _1-18 ester is the same as described above.

As C _1-18 ester, each of R ₃ and R ₄ of R ₃ —COO—R ₄ is, for example, C _1-18 alkyl, C _1-18 alkenyl, C _1-18 alkynyl, C _3-7 cycloalkyl. , C _3-7 cycloalkyl-C _1-12 alkyl, C _6-14 aryl, C _6-10 aryl-C _1-12 alkyl, C _1-18 ether or C _1-18 ester Can be mentioned. Where C _1-18 alkyl, C _1-18 alkenyl, C _1-18 alkynyl, C _3-7 cycloalkyl, C _3-7 cycloalkyl-C _1-12 alkyl, C _6-14 aryl, C _{6-6 10} aryl-C _1-12 alkyl, C _1-18 ether or C _1-18 ester is the same as described above.

  The reaction liquid obtained by the above reaction is concentrated under reduced pressure, and water is added to the obtained residue, followed by extraction with an organic solvent, whereby a silicon nanoparticle phosphor can be obtained.

(Adjusting the particle size of silicon nanoparticles)
First, the step of reacting the alloy powder represented by Mg ₂ Si with silicon tetrachloride (SiCl ₄ ) is represented by reaction step (1), and the silicon compound obtained by the reaction step (1) is represented by RMgX or RLi. If the step of reacting the alkylating agent to be reacted is the reaction step (2), the reaction step (1) is larger than the reaction step (2) with respect to the Si (silicon) particle size as the final product. Influence. That is, since the size of the final silicon particles is hardly affected by the reaction step (2), the size of the final silicon particles is determined by the reaction step (1).
In the reaction step (1), the Si (silicon) particle size decreases as the reaction temperature is increased. Usually, it is performed at 0 ° C. or higher, but it is preferably performed at 150 ° C. or lower.
Further, when the reaction time is lengthened, the Si (silicon) particle size increases. Usually, it is performed for 1 day or longer, but it is preferably performed for 10 days or shorter.
Further, when the reaction pressure is increased, the Si (silicon) particle size increases. Usually, the reaction is carried out at normal pressure or higher, but is preferably carried out at 10 MPa or less.
Further, when the stirring time is lengthened, the Si (silicon) particle size decreases. Here, silicon nanoparticles having a desired size can be obtained by appropriately adjusting the reaction time and the stirring time.
Furthermore, when the reaction is performed in a solvent that further suppresses the reaction in the first step, the Si (silicon) particle size can be increased. This is because if the rapid reaction between Mg ₂ Si and SiCl ₄ is suppressed, the silicon nanoparticles grow slowly and become larger.
The size of the silicon nanoparticles corresponds to the wavelength of visible light emitted by the particles. When the size of the silicon nanoparticles increases, for example, the emission wavelength of the silicon nanoparticles by ultraviolet excitation becomes longer. It becomes possible to emit visible light. Generally, the particle size of a phosphor emitting violet light (about 380 nm to about 430 nm) is about 1.09 nm to about 1.21 nm, and the size of a phosphor emitting blue light (about 430 nm to about 460 nm) is about The particle size of the phosphor emitting blue-green light (about 460 nm to about 500 nm) from 1.21 to about 1.35 nm is about 1.35 to about 1.50 nm, and the green light (about 500 nm to about 570 nm) is emitted. The particle size of the phosphor emitting is about 1.50 to about 1.69 nm, and the particle size of the phosphor emitting yellow light (about 570 nm to about 590 nm) is orange light from about 1.69 to about 1.79 nm. The particle size of the phosphor emitting (about 590 nm to about 610 nm) is about 1.79 to about 1.85 nm, and the particle size of the phosphor emitting red light (about 610 nn to about 780 nm) is about 1.85 to about 1.85 nm. This corresponds to about 2.19 nm.
In the reaction step (2), the hydrocarbon group is bonded to the outer peripheral portion of the silicon particle to cover the surface of the silicon nanoparticle with the hydrocarbon group, thereby preventing the oxidation of the silicon nanoparticle. It is possible to prevent changes in the emission wavelength and emission efficiency of the particles.

(Bio tag)
A biotag is composed of two parts, a labeling part and a binding part, which binds to a biological substance by this binding part and indicates its presence by a labeling part. When the reactive group in the binding part of the biotag binds to a biological substance, and the binding part is irradiated with, for example, ultraviolet rays, the silicon nanoparticle phosphor as the labeling part emits visible light. Can be recognized. In the present invention, the above-mentioned bonding portion is one in which the reactive group Y is bonded to the end of the R group. R is C _1-18 alkyl, C _1-18 alkenyl, C _1-18 alkynyl, C _3-7 cycloalkyl, C _3-7 cycloalkyl-C _1-12 alkyl, C _6-14 aryl, C _{6-6 10} aryl-C _1-12 alkyl, C _1-18 ether, or C _1-18 ester. This C _1-18 alkyl, C _1-18 alkenyl, C _1-18 alkynyl, C _3-7 cycloalkyl, C _3-7 cycloalkyl-C _1-12 alkyl, C _6-14 aryl, C _6-10 aryl Specific examples of —C _1-12 alkyl, C _1-18 ether and C _1-18 ester are the same as described above.
The reactive group Y may be any substance as long as it binds to a biological substance. In particular, the reactive group Y is selected from the group consisting of alkyl halides, hydroxyl groups, amino groups, carboxylic acids, isothiocyanates, silicon halides, boronic acids, succinimide esters, sulfonyl halides, mercaptans, and hydrazines. preferable.
In the present invention, the labeling part is a silicon nanoparticle phosphor. When the labeling part of the biotag is made of silicon nanoparticles, unlike a conventional phosphor containing cadmium or the like, there is no toxicity to the living body.

(Biotag manufacturing method)
(First reaction step)
Similar to the first reaction step, Si atoms are three-dimensionally bonded to form a substantially spherical cluster, and a silicon compound in which Cl atoms are bonded to Si atoms around the spherical body is obtained.
(Second reaction step)
Subsequently, the reactive group Y (Y is a halogenated group) at the terminal of the R group of the alkylating agent represented by the above silicon compound and the formula: RMgX or RLi (wherein R and X are the same as those described above). Alkyl, hydroxyl group, amino acid, carboxylic acid, isothiocyanate, silicon halide, boronic acid, succinimide ester, sulfonyl halide, mercaptan, or hydrazine) are combined in a solvent and reacted. . This solvent is the same as the above solvent. The solvent used in the second reaction step may be the same as or different from the solvent used in the first reaction step. The compound in which the reactive group Y is bonded to the R group end of the RMgX or RLi is added to the silicon compound obtained in the first reaction step at a constant concentration (1% to 10%). In this second reaction step, the reactive group Y is preferably protected with a protecting group Z (Z is an alkyl group, an arylmethyl group, an arylcarbonyl group, or an alkyloxycarbonyl group). Here, “protecting” means that the protecting group Z binds to the binding site of the reactive group Y with the biological substance and surrounds the reactive group Y. When the reactive group Y binds to the biological substance, the protective group Z is detached from the reactive group Y.
The reaction conditions in the second step are the same as above. The compound obtained here can be post-treated in the same manner as described above to obtain a biotag.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail and concretely, this invention is not limited to a following example.

Under an argon gas stream, in a three-necked flask with an internal volume of 100 ml equipped with a thermometer and a stirrer, 0.2 ml of silicon tetrachloride (SiCl ₄ ), 100 mg of Mg ₂ Si, and 50 ml of tetrahydrofuran (THF) as a solvent added. Then, it was made to react at 45 degreeC under argon gas stream for 1 week (no stirring). By concentrating the reaction solution under reduced pressure, unreacted silicon tetrachloride (SiCl ₄ ) and the reaction solvent were removed, and a silicon compound was obtained. This silicon compound is a compound in which Si atoms are three-dimensionally bonded to form a substantially spherical shape, and Cl atoms are bonded to Si atoms around the sphere.

  Thereafter, 50 ml of tetrahydrofuran, which is a solvent, was added to the obtained product under an argon stream, and 2.6 ml of 2M n-BubutylMgCl was further added dropwise, followed by stirring at room temperature for 1 day under an argon stream. While reacting. Then, after removing the solvent under reduced pressure, 100 ml of water was added to remove the salt, and the mixture was extracted with 150 ml of hexane. By removing the solvent under reduced pressure, 30 mg of a silicon nanoparticle phosphor was obtained. FIG. 1 shows an emission spectrum of silicon nanoparticles prepared by the method of Example 1 by ultraviolet excitation. The horizontal axis represents the emission wavelength, and the vertical axis represents the emission intensity. The emission wavelength peak of this silicon nanoparticle phosphor was 430 nm, and a sharp distribution was obtained (FIG. 1).

Under a stream of argon gas, 100 mg of Mg ₂ Si and 50 ml of dimethoxyethane as a solvent were added to a 100 ml three-necked flask equipped with a thermometer and a stirrer, and then 0.2 ml of silicon tetrachloride (SiCl ₄ ) was added. added. Then, it was made to react, stirring for 4 days at 90 degreeC under argon gas stream. The reaction solution is concentrated under reduced pressure to remove unreacted silicon tetrachloride (SiCl ₄ ) and the reaction solvent, and Si atoms are three-dimensionally bonded to form a substantially spherical shape. A silicon compound in which a plurality of Cl atoms were bonded to Si atoms constituting the sphere on the surface was obtained.

  Thereafter, 50 ml of dimethoxyethane as a solvent was added to the obtained product under an argon stream, and 2.6 ml of 2M n-BuMgCl was added dropwise, followed by a reaction while stirring at room temperature for 1 day under an argon stream. I let you. Then, after removing the solvent under reduced pressure, 100 ml of water was added to remove the salt, and the mixture was extracted with 150 ml of hexane. By removing the solvent under reduced pressure, 15 mg of a silicon nanoparticle phosphor was obtained.

The present invention relates to silicon nanoparticles that stably emit light with high efficiency and a method for producing the same, and can be used as a light emitting material for display devices and a fluorescent material for biotags.

Emission spectrum of silicon nanoparticles obtained in Example 1 by ultraviolet excitation

Claims (8)

A hydrocarbon group represented by R (R is C _1-18 alkyl, C _1-18 alkenyl, C _1-18 alkynyl, C _3-7 cycloalkyl, C ₃₎ is formed on the surface of silicon nanoparticles having a particle size of 1 to 5 nm. _-7 cycloalkyl-C _1-12 alkyl, C _6-14 aryl, C _6-10 aryl-C _1-12 alkyl, C _1-18 ether, or C _1-18 ester) A silicon nanoparticle phosphor characterized in that the emission wavelength of is in the visible region. A first step of reacting an alloy powder represented by Mg ₂ Si with silicon tetrachloride (SiCl ₄ ) in a reaction solvent;
The resulting silicon compound and the formula: RMgX or RLi (wherein R is C _1-18 alkyl, C _1-18 alkenyl, C _1-18 alkynyl, C _3-7 cycloalkyl, C _3-7 cycloalkyl) -C _1-12 alkyl, C _6-14 aryl, C _6-10 aryl-C _1-12 alkyl, C _1-18 ether or C _1-18 ester, X represents a halogen atom) Comprising the second step of reacting with the agent,
A method for producing silicon nanoparticles, comprising obtaining a silicon nanoparticle phosphor having a particle size of 1 to 5 nm, wherein the hydrocarbon group represented by R is bonded on the surface.   3. The silicon nanoparticle phosphor according to claim 2, wherein the first step is performed in a reaction solvent in an argon gas atmosphere at a reaction temperature of 0 ° C. to 150 ° C. and a pressure of normal pressure to 10 MPa for 1 day to 10 days. Manufacturing method. In the first step, the silicon tetrachloride to the alloy powder represented by _{Mg 2 Si (SiCl 4),} 1 weight (g) ratio: 1 to 1: according to claim 2 or 3 used in the 10 A method for producing a silicon nanoparticle phosphor. The ratio of the volume (L) of the solvent to the weight (g) of the alloy powder represented by Mg ₂ Si in the first step is 1: 0.1 to 1: 1. The manufacturing method of the silicon nanoparticle fluorescent substance in any one of.   The reaction solvent is diglyme, triglyme, dioxane, methyl isobutyl ketone (MIBK), tetrahydrofuran (THF), methyl t-butyl ether (MTBE), polyethylene glycol (PEG), toluene, xylene, nitrobenzene. 6. The silicon nanoparticle phosphor according to claim 2, which is at least one solvent selected from the group consisting of n-heptane, n-hexane, chloroform, methylene chloride, diethyl ether, and petroleum ether. Manufacturing method.   The silicon nanoparticle phosphor according to claim 1, wherein the hydrocarbon group has a reactive group Y for use as a biotag. The reactive group Y is one selected from the group consisting of alkyl halides, hydroxyl groups, amino groups, carboxylic acids, isothiocyanates, silicon halides, boronic acids, succinimide esters, sulfonyl halides, mercaptans, and hydrazines. The silicon nanoparticle phosphor according to claim 7.

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