JP2003160336A - Production method for compound semiconductor superfine particulate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for mass-producing a semiconductor particulate while suppressing, in advance, an unfavorable reaction before the semiconductor raw material is charged into a reaction vessel. <P>SOLUTION: This method is characterized in that a compound semiconductor superfine particulate is produced by a hot soap process while independently feeding a raw material including the elements of the 11th to 13th group in the periodic table and that including the elements of the 15th to 17th group into a tubular flow reactor. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing ultrafine semiconductor particles. More specifically, in a method for producing ultrafine semiconductor particles using a tubular flow reactor, two kinds of semiconductor raw materials are individually supplied to a reactor to prevent undesired pre-reaction and to allow the reaction to proceed stably. At the same time, it relates to a manufacturing method capable of easily changing properties such as particle size and dispersibility of semiconductor ultrafine particles. The semiconductor ultrafine particles obtained by the production method of the present invention are suitably used as a raw material for optical members such as displays and light emitting diodes. In addition, since it has a characteristic that the half-width of the emission band is narrow, it can be used as a luminescent biological analysis reagent such as a fluorescent immunoassay or a cell marker. Further, the colored semiconductor ultrafine particles can be used as a coloring material such as a pigment.

[0002]

2. Description of the Related Art Semiconductor materials have a characteristic of giving light absorption and light emission peculiar to the materials, and are already widely used as light emitting materials. It is known that semiconductor ultrafine particles having a particle size of about 1 nm to 30 nm exhibit a property different from that of bulk due to the quantum confinement effect. Ultrafine particles having such properties include colloidal particles and nanocrystals (Nanocry
stals), nanoparticles (Nanoparticle)
s), or a quantum dot (Quantum Dot) or the like.

Conventionally, semiconductor ultrafine particles have been manufactured, for example, by the following method. (A) A high vacuum process such as a molecular beam epitaxy method or a CVD method. Although highly pure semiconductor ultrafine particles whose composition is highly controlled can be obtained by this method, it may be used as a raw material from toxic gases such as phosphine and arsine, and an expensive manufacturing apparatus is required. There was a limit to the above usage. (B) A method of allowing a semiconductor raw material aqueous solution to exist as a reverse micelle in a hydrophobic organic solvent and utilizing a mass transfer associated with collision between the reverse micelles to grow a semiconductor crystal in the reverse micelle phase (hereinafter, reverse micelle Called the law). For example, B. S. Zou
Int. J. Quant. Chem. , Volume 72, 4
39-450 (1999). A known reverse micelle stabilization technique can be used in a general-purpose reaction kettle, and the reaction involves water, which is a simple method because it is performed at a relatively low temperature. (C) A method of injecting a thermally decomposable semiconductor raw material into a high temperature coordinating organic compound to grow a semiconductor crystal (hereinafter referred to as a hot soap method). For example, C.I. B. Murray et al .;
J. Am. Chem. Soc. , 115 Volume 8706-8
715 (1993). This method is characterized in that excellent semiconductor ultrafine particles having an extremely narrow particle size distribution and few impurities can be obtained.

Therefore, the liquid phase production method of (b) or (c) is considered to be a method more suitable for industrial production than the high vacuum process of (a). It has only been considered on the reaction scale. Therefore, development of a method for industrially producing semiconductor ultrafine particles is desired. In particular, the semiconductor ultrafine particles produced by the method (c) have a narrow particle size distribution and high luminous efficiency, and are therefore particularly suitably used as raw materials for optical members such as displays and light emitting diodes.

When the semiconductor ultrafine particles are produced by the hot soap method (c), the emission intensity and the dispersibility in the medium depend on the amount ratio of the 11th to 13th group elements and the 15th to 17th group elements of the periodic table used as raw materials. Such a property changes. However, in the hot soap method, the C. B. Murray et al .;
Am. Chem. Soc. , 115, 8706-871
5 (1993), a raw material containing a Group 11 to 13 element of a compound semiconductor (hereinafter abbreviated as a positive raw material) and a Group 15 to 17 element of a compound semiconductor are included. Since a raw material (hereinafter abbreviated as a negative raw material) is mixed in advance and supplied into a coordinating organic compound heated to a high temperature to produce high-quality ultrafine particles, the positive raw material In order to change the amount ratio of the negative raw material, it was necessary to repeat the reaction operation from the beginning.

Furthermore, the hot soap method is generally a reaction at a high temperature because of the nature of the reaction utilizing the thermal decomposition of raw materials.
When manufacturing in a flow-through process, it is unavoidable that the heat of the reactor is transferred to the raw material supply line by heat transfer and the positive raw material and the negative raw material in the supply line are heated. If a positive raw material and a negative raw material are mixed and supplied in advance, the reaction proceeds before entering the reactor, and not only ultrafine particles having the desired properties cannot be obtained.
When the degree is high, there is a problem that a blockage is produced as a by-product in the supply line.

US 6,179,912 B1 (Bio
Crystal Ltd. ) Implements this hot soap method in a distribution process, it is essential to mix the positive and negative raw materials before entering the reactor. It is difficult to continuously change the ratio, and the reaction proceeds immediately before the reactor, resulting in a wide particle size distribution and clogging.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to stably and in large quantity by manufacturing semiconductor raw materials by preventing them from reacting before entering a reactor. An object of the present invention is to provide a production method capable of easily changing the properties of fine particles.

[0009]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in order to achieve the above object, it is not preferable because the positive raw material and the negative raw material used for the reaction are independently supplied to the reactor. The present invention has arrived at the present invention by finding a production method capable of suppressing the reaction in advance and easily changing the characteristics (particle size, dispersibility, etc.) of the obtained product.

That is, the present invention is a method for producing ultrafine compound semiconductor particles by a hot soap method using a tubular flow reactor, wherein a raw material containing an element of groups 11 to 13 of the periodic table and a group of 15 to 17 are used. The method for producing compound semiconductor ultrafine particles is characterized in that the raw material containing the element is independently supplied to the reactor.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
It [Semiconductor ultrafine particles] Semi-obtained by the production method of the present invention
Examples of the conductive fine particles include tin (IV) oxide (Sn
O₂), Tin sulfide (II, IV) (Sn (II) Sn (IV)
S₃), Tin sulfide (IV) (SnS₂), Tin (II) sulfide (S
nS), tin (II) selenide (SnSe), tin telluride
(II) (SnTe), lead sulfide (PbS), lead selenide
(PbSe), Lead Telluride (PbTe), etc. Periodic Table 1
Compound of Group 4 element with Group 16 element of the periodic table, boron nitride
(BN), boron phosphide (BP), boron arsenide (BA
s), aluminum nitride (AlN), aluminum phosphide
Aluminum (AlP), aluminum arsenide (AlAs), anti
Aluminum monmonide (AlSb), gallium nitride (Ga
N), gallium phosphide (GaP), gallium arsenide (Ga)
As), gallium antimonide (GaSb), nitride nitride
Indium (InN), indium phosphide (InP), arsenic
Indium (InAs), indium antimonide (I
nSb) and other periodic table group 13 elements and periodic table group 15 elements
And a compound (in the present invention, a group 13-15 compound
Conductor), aluminum sulfide (Al₂S₃),
Aluminum lenide (Al₂Se₃ ), Gallium sulfide
(Ga₂S₃), Gallium selenide (Ge₂Se₃),
Gallium telluride (Ga₂Te₃), Indium oxide
(In₂O₃ ), Indium sulfide (In₂S₃ ), Cele
Indium nitride (In₂Se₃), Indium telluride
(In₂ Te₃) Etc. Periodic Table Group 13 elements and Periodic Table 1st
Compound with Group 6 element, thallium (I) chloride (TlC
l), thallium (I) bromide (TlBr), tariu iodide
Periodic Table Group 13 elements such as aluminum (I) (TlI)
Compounds with Group 17 elements, zinc oxide (ZnO), zinc sulfide
(ZnS), zinc selenide (ZnSe), zinc telluride
(ZnTe), cadmium oxide (CdO), cadmium sulfide
Um (CdS), cadmium selenide (CdSe), te
Cadmium luluride (CdTe), mercury sulfide (HgS),
Mercury selenide (HgSe), mercury telluride (HgTe)
Of periodic table group 12 elements and other periodic table group 16 elements
Thing (referred to as a group 12-16 compound semiconductor in the present invention)
), Antimony sulfide (III) (Sb₂S₃ ),selenium
Antimony (III) oxide (Sb₂Se₃), Ann Tellurium
Zimon (III) (Sb₂ Te₃ ), Bismuth sulfide (III)
(Bi₂ S₃), Bismuth selenide (III) (Bi₂S
e₃) Bismuth (III) telluride (Bi₂Te₃) Etc.
A compound of an element of Group 15 of the periodic table and an element of Group 16 of the periodic table,
Copper (I) oxide (Cu₂ O) and other periodic table group 11 elements
Compound with Group 16 element in the periodic table, copper (I) chloride (CuC
l), copper (I) bromide (CuBr), copper (I) iodide (C)
uI), silver iodide (AgI), silver chloride (AgCl), odor
Periodic Table Group 11 elements such as silver halide (AgBr) and Periodic Table 1
Compound with Group 7 element (in the present invention, Group 11-17)
Compound semiconductor), nickel (II) oxide (Ni
O) and other elements of Group 10 of the periodic table and elements of Group 16 of the periodic table
Compounds, cobalt (II) oxide (CoO), cobalt sulfide
(II) (CoS), etc. Periodic table Group 9 element Periodic table 1st
Compound with Group 6 element, triiron tetroxide (Fe ₃ O_Four ), Sulfide
Periodic Table Group 8 elements such as iron (II) (FeS) and Periodic Table 1
Compounds with Group 6 elements, manganese (II) oxide (MnO), etc.
A compound of an element of Group 7 of the periodic table with an element of Group 16 of the periodic table,
Molybdenum sulfide (IV) (MoS₂), Tungsten oxide
(IV) (WO₂ ) Etc. Periodic Table Group 6 element and Periodic Table 16th
Compounds with group elements, vanadium (II) oxide (VO), acids
Vanadium (II) (VO)₂), Tantalum oxide (V)
(Ta₂ O_Five ) Etc. Periodic Table Group 5 elements and Periodic Table Group 16
Compounds with elements, titanium oxide (TiO₂ , Ti₂O_Five,
Ti₂O₃, Ti_FiveO₉ Etc.) etc. with the periodic table group 4 element
Compound with Group 16 element of the periodic table, magnesium sulfide (M
gS), magnesium selenide (MgSe), etc.
Compound of Group 2 element and Group 16 element of the periodic table, oxidized cad
Mium (II) Chromium (III) (CdCr₂ O_Four), Cele
Cadmium (II) Chromide (III) (CdCr)₂ Se_Four
 ), Copper (II) sulfide chromium (III) (CuCr₂ S_Four),
Mercury (II) selenide Chromium (III) (HgCr₂Se
_Four ) Etc. chalcogen spinels, barium titanate
(BaTiO₃) And the like.

Among the above, the eleventh one such as AgI is particularly preferable.
Group 17 compound semiconductors, CdSe, CdS, ZnS, Zn
Group 12-16 compound semiconductors such as Se, InAs, In
It is any of the compound semiconductors mainly composed of Group 13-15 compound semiconductors such as P. In addition, the periodic table used in the present invention shall comply with the IUPAC Inorganic Chemistry Nomenclature 1990 Rules.

In addition, the inside or the outer shell of the ultrafine particles is doped with any activator (meaning that it is intentionally added).
It does not matter. Examples of such activators include:
Examples include manganese, terbium, erbium, europium, and the like. The semiconductor ultrafine particles produced according to the present invention are mainly composed of semiconductor crystals having a particle size of several nm to several tens nm as described later,
The composition of the semiconductor crystal may be either a simple substance having semiconductor properties or a compound semiconductor composed of plural kinds of elements. The main component of the semiconductor ultrafine particles referred to here means a central portion of the surface of the ultrafine particles, which will be described later, excluding organic components.

The organic molecules such as ligands used in the production of the semiconductor ultrafine particles, or organic components such as organic structures formed by the chemical changes of these molecules, that is, "coordinating organic compounds", are formed on the surface thereof. You can keep it in.
Further, the semiconductor ultrafine particles may be obtained as a mixture with the aforementioned coordinating organic compound, which is mixed during the isolation and purification step of the semiconductor ultrafine particles.

There is no limitation on the binding mode between the organic component retained on the surface of the particle and the semiconductor composition, but relatively strong chemical bonds such as coordination bond, covalent bond, ionic bond, van der Waals force, and hydrogen. Examples include relatively weak reversible attractive interactions such as binding, hydrophobic-hydrophobic interaction, and entanglement effect of molecular chains. The content of the coordinating organic compound component retained in the semiconductor ultrafine particles depends on the surface area of the generated semiconductor ultrafine particles (that is, also related to the particle size),
In the state of being sufficiently purified through the isolation and purification process described below,
In the semiconductor ultrafine particles containing a coordinating organic compound, usually 1 to 9
0% by weight, preferably 5 to 8 in terms of dispersibility of various practically important mediums for dispersing semiconductor ultrafine particles (for example, solvent and resin binder) in an organic matrix substance and chemical stability.
It is 0% by weight, more preferably 10 to 70% by weight, and most preferably about 15 to 60% by weight. The content of the organic component is measured, for example, by various elemental analysis or thermogravimetric analysis. In addition, information on the chemical species and chemical environment of the organic component can be obtained by infrared absorption spectrum (IR) and nuclear magnetic resonance (NM).
R) Obtained from spectrum.

The size of the semiconductor ultrafine particles obtained by the production method of the present invention is usually 1 to 20 nm, preferably 1.5 to 15 nm, more preferably the average particle size observed by a transmission electron microscope (TEM). Is about 2 to 12 nm, and most preferably about 2.5 to 10 nm. The semiconductor ultrafine particles obtained by the production method of the present invention may contain an organic component as the surface layer as described above, but the particle image (average particle size) observed by TEM shows a portion not containing such an organic component. That is, it is derived from the part of the semiconductor composition.

Since the wavelength of light absorption and / or emission due to the electronic transition in the quantum level caused by the quantum effect of the semiconductor ultrafine particles is determined by the size of the particle, the average particle diameter is out of the above range. In this case, not only the important emission wavelength tends to be difficult to obtain, but also isolation and purification after the reaction tends to be difficult. The generation of the semiconductor crystal structure is
In addition to observing the semiconductor crystal lattice image in the TEM observation, powder X-ray diffraction of ultrafine particles, elemental analysis, or XA
FS (X-ray absorption fine)
It can be confirmed by an analysis means such as an element analysis by a structure) and an interatomic distance measurement. [Particle size distribution] The particle size distribution of the semiconductor ultrafine particles is determined by a value (%) obtained by dividing the standard deviation of the particle size measured by the TEM by the average particle size by 100 (%). The smaller the size, the finer the particles are.
Conversely, if this value is large, it means that the particles are not uniform in size. The particle size distribution of the ultrafine particles containing the ultrafine particles of the present invention is preferably 5% or more and less than 30%. If it is less than 5%, the interaction between particles to be described later becomes unclear, and the distance between particles tends not to be evaluated, and the yield at the time of production of ultrafine particles decreases, so the cost of a film using the ultrafine particles becomes low. Tends to rise. Also,
When it is 30% or more, for example, when it is used as an optical memory material, the ratio of fluorescence of a specific wavelength to be detected is small, so that the intensity cannot be obtained and it tends to be difficult to use. For the above reasons, more preferably 8% or more and less than 20%,
Most preferably, it is 10% or more and less than 15%.

[Manufacturing Method of Ultrafine Particles] As the manufacturing method of the semiconductor ultrafine particles, there are the high vacuum process such as the molecular beam epitaxy method, the reverse micelle method, and the liquid phase manufacturing method such as the hot soap method as described above. To be Among them, the hot soap method of the present invention is an excellent production method because it has an extremely narrow particle size distribution and obtains ultrafine particles having high luminous efficiency. Hereinafter, the manufacturing method by the hot soap method of the present invention will be described in detail.

[Hot-Soap Method] The hot-soap method is a reaction that starts as a result of thermal decomposition of a semiconductor raw material in a coordinating organic compound heated to a high temperature of, for example, 100 ° C. or higher, to generate nuclei of semiconductor crystals and crystal growth. Is a method of progressing. For the purpose of desirably controlling the reaction rate in the processes of such crystal nucleus generation and crystal growth, a coordinating organic compound having an appropriate coordinating force for a semiconductor constituent element is used as an essential component in the reaction. Since the situation in which such a coordinating organic compound is coordinated and stabilized with a semiconductor crystal is similar to the situation in which soap molecules stabilize oil droplets in water, this reaction mode is based on hot soap (H
This is called the ot soap method.

[Semiconductor Raw Material Used in Hot Soap Method] The semiconductor raw material used in the hot soap method is preferably liquid for reasons of simplicity in manufacturing operation. If the raw material itself is a liquid at room temperature, it may be used as it is, and if necessary, a solution of an appropriate organic solvent may be used. Such organic solvents include alkanes such as n-hexane,
Aromatic hydrocarbons such as toluene, or the coordination organic compounds exemplified above are exemplified. Similarly, when the raw material itself is a solid, a solution of an appropriate organic solvent such as alkanes, aromatic hydrocarbons, and coordinating organic compounds may be used.

Among the group 11 to 13 elements of the compound semiconductor, Ag, Cd and Zn are preferable, and the raw materials containing them are alkyl metal compounds such as dimethyl cadmium, diethyl zinc and tributyl indium, cadmium acetate and carbonic acid. Examples thereof include salts such as cadmium and zinc nitrate, oxides such as cadmium oxide and indium oxide, and the like.

Further, as the Group 15 to 17 elements of the compound semiconductor, S, Se and I are preferable, and as a raw material containing them, trialkylphosphine compounds such as tributylphosphine selenide and trioctylphosphine selenide. , Hexamethyldisilathiane, trimethylsilyl compounds such as tris (trimethylsilyl) arsine, hydrogen sulfide gas, or simple selenium, sulfur,
Examples include phosphorus and arsenic.

When compound semiconductor ultrafine particles are obtained by the hot soap method of the present invention, the molar ratio of the above Group 11-13 element to Group 15-17 element in the semiconductor raw material used is usually 0.5-5, It is preferably 0.8 to 3, and most preferably about 0.9 to 2.5. In the present invention, the ratio of positive element to negative element (positive element / negative element) is 1.1.
By making the amount more than twice, the amount of ligand on the semiconductor ultrafine particles can be increased. By changing the amount ratio of the raw materials in this way, the optimum dispersion performance can be obtained depending on the properties of the medium (solvent, polymer). Ultrafine particles can be controlled.

[Semiconductor Raw Material Supply Method] In the production method of the present invention, the positive raw material and the negative raw material are separately supplied to the reactor. Here, for the method of supply, it is possible to make a supply pipe for each raw material independently and attach it to the reactor, but in order to simplify the liquid transfer process, one raw material is mixed with the coordinating organic compound in advance. May be supplied. Z. Adam et al .; Am.
Chem. Soc. , Vol. 183-184 (2000)
Report that when the same positive raw material as used in the present invention and a coordinating organic compound are mixed and heated to a high temperature, the positive raw material causes undesired thermal decomposition. That is, it is impossible to produce good semiconductor ultrafine particles by mixing the positive raw material with the coordinating organic compound in advance by the conventional batch method. Since the production method using the tubular flow reactor of the present invention has a characteristic that the heat transfer area with respect to the liquid transfer amount is large, it is possible to rapidly raise the temperature in a short time and suppress the thermal decomposition of the raw material as much as possible. Is possible. Further, although the reason is not clear, it is preferable to pre-mix in the coordinating organic compound is a raw material containing a positive element,
When raw materials containing negative elements are mixed, high quality semiconductor ultrafine particles may not be produced.

Further, the production method of the present invention is characterized in that the supply ratio of the positive raw material and the negative raw material can be controlled during the continuous reaction. The semiconductor ultrafine particles have a structure in which a coordinating organic compound is coordinated around a semiconductor crystal in the central portion thereof. The coordinating organic compound is believed to be coordinated with the outermost shell Group 11 to 13 elements of the semiconductor crystal in the central portion, and the ratio of the number of outermost shell Group 11 to 13 elements is large. It is densely covered with coordinating organic compounds. In general, the denser the coverage with the coordinating organic compound is, the higher the luminous efficiency is, but the more difficult it is to handle, such as the difficulty in receiving ligand substitution after the production and the difficulty in forming a film. Therefore, it is a great advantage that the supply ratio of the positive raw material and the negative raw material can be changed according to the method of using the ultrafine particles to be produced. At this time,
The supply amount ratio of the positive raw material and the negative raw material is described in the above-mentioned semiconductor raw material used in the hot soap method.
This is a range in which the molar ratio of the group element to the group 15 to 17 element is realized.

[Coordinating Organic Compound Used in Hot Soap Method] Tributyl is an example of a substance in which the coordinating organic compound used in the reaction is coordinated and stabilized with a semiconductor crystal in a high temperature liquid phase. Trialkylphosphines such as phosphine and trioctylphosphine, trialkylphosphine oxides such as tributylphosphine oxide and trioctylphosphine oxide, hexadecylamine,
Alkylamines such as dodecylamine are typical,
Among them, a trialkylphosphine having an alkyl group having 4 to 10 carbon atoms, particularly trioctylphosphine oxide, has a high boiling point and stably exists even in the presence of air, and thus is most preferably used. If necessary, a plurality of such coordinating organic compounds may be mixed and used. Alternatively, a solution of an appropriate organic solvent may be used. When used as a solution of an organic solvent, advantages such as no need to keep a tank for storing a coordinating organic compound, which will be described later, can be expected.

[Reaction conditions] The reaction temperature is usually 100 to 50.
0 ° C, preferably 200 to 400 ° C, more preferably 2
It is 50 to 370 ° C., and is usually carried out at normal pressure. Also,
The residence time is usually 1 second to 5 hours, preferably 3 seconds to 1 hour, more preferably 10 seconds to 10 minutes.

[Flow-type of reaction type] A conceptual diagram of a typical manufacturing apparatus using the hot soap method is shown in FIG. Such an apparatus is generally roughly divided into four parts of a coordinating organic compound supply system, a semiconductor raw material supply system, a reaction system, and a product storage system, but is not limited to the configuration of the conceptual diagram. Hereinafter, this will be sequentially described as an example. (A) Coordinating organic compound supply system ... The coordinating organic compound 2 in the tank 1 for storing the coordinating organic compound is heated by the heat retaining device 3 and kept in a liquid state. Coordinating organic compound 2
Is injected into the reactor 7 from the flow path 4 through the liquid feed pump 5 and the injection flow path 6. Here, the coordinating organic compound 2 may be preheated by the preheating device 8 and then supplied to the reactor 7 after passing through the liquid delivery pump 5. As described above, the positive raw material and a suitable organic solvent may be mixed in advance with the coordinating organic compound 2 and supplied to the reactor at the same time. (B) Semiconductor raw material supply system: The positive raw material 10 in the raw material tank 9 for storing the positive raw material passes through the flow path 11 and the liquid feed pump 12
Is supplied to. The positive raw material 10 discharged from the liquid feed pump 12 is supplied to the reactor 7 through the flow path 13. Further, any positive raw material supply system may be independently heated or cooled by the preliminary temperature controller 14 as necessary. Here, when this positive raw material is mixed with the above-mentioned coordinating organic compound and supplied, 9 to 14 are unnecessary, and the step of supplying this positive raw material is omitted. On the other hand, the negative raw material 16 in the tank 15 for storing the negative raw material is supplied to the liquid feed pump 18 through the flow path 17. The negative raw material 16 discharged from the liquid feed pump 18 is supplied to the reactor 7 through the flow path 19.
Further, any negative raw material supply system may be independently heated or cooled by the preliminary temperature control device 20 as needed. (C) Reaction system: The reactor 7 is heated by the reaction heating device 21 and maintains a temperature suitable for the reaction. The coordinating organic compound 2 and the positive raw material 10 are united and mixed at the point 28. However, the point 28 does not exist when the positive raw material and the coordinating compound are mixed and supplied in advance. The mixed liquid of the coordinating organic compound 2 and the positive raw material 10 and the negative raw material 16 are combined and mixed at a point 22 in the reactor, where the reaction is started. The shape of the point 22 or the point 28 is usually T-shaped or Y-shaped.
It is a letter-shaped junction. The reaction liquid phase 23 thus generated flows through the reaction liquid flow path 24 and is stored in the product storage tank 25. During this time, it may be heated by the aging heating device 26 to be aged. (D) Product storage system: The product storage 25 is heated or cooled by the product temperature control device 27, and the temperature is adjusted so that the reaction liquid phase 23 in which the intended reaction or aging heating is completed can exist stably. .

In the hot soap method apparatus, the internal space in which the liquid phase flows or stays is usually under a dry inert gas (for example, argon or nitrogen) atmosphere in at least a heated portion for the purpose of suppressing deterioration of the product. Preferably, the entire system is under such an inert gas atmosphere. In some cases, shading measures are preferable for the same reason. [Isolation and Purification of Ultrafine Particles] The semiconductor ultrafine particles produced by the hot soap method can be isolated and purified from a state containing a large amount of extra coordination organic compounds. As this method, there is a method of mixing the coordinating organic compound with a solvent having a high solubility but the generated ultrafine particles having a low solubility, for example, alcohols such as methanol and ethanol, and ketones such as acetone. In this case, since a suspension in which the ultrafine particles are deposited is generated, it is possible to isolate the semiconductor ultrafine particles containing no excess coordinating organic compound by a separation method such as centrifugation or filtration.

[0030]

EXAMPLES Hereinafter, specific embodiments of the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded. In addition,
Unless otherwise specified, the raw material reagents used were those supplied by Aldrich without purification. Moreover, the measuring apparatus and conditions of an optical spectrum are shown below. (1) Absorption spectrum: A solution sample was measured in a quartz cell with an optical path length of 1 cm using an HP8453 type UV-visible absorptiometer manufactured by Hewlett Packard. (2) Emission spectrum: F250 manufactured by Hitachi, Ltd.
Using a 0 spectrofluorometer, sample the solution with an optical path length of 1c
m in a quartz cell. The wavelength of the excitation light was 365 nm in the case of cadmium selenide ultrafine particles and 366 nm in the case of cadmium sulfide ultrafine particles.

Example 1 [Distribution production of cadmium sulfide ultrafine particles by hot soap method] (1) Preparation of raw material liquid Trioctylphosphine oxide (TOPO; 390 g) was prepared as a coordinating organic compound in air at room temperature. It is placed in a 1 L glass receiver corresponding to the tank 1 described in 1, and a dry argon gas line and a lid provided with a gas vent are put and argon gas is circulated for 1 hour to replace the inside with an argon atmosphere.

On the other hand, at room temperature, in a glove box kept in a dry argon atmosphere, tri-n-as a solvent was used.
Butylphosphine (purity 99%; 116.6 g) was added to 30
Fractionate into a 0 ml Erlenmeyer flask, add dimethyl cadmium (purity 99 +%) hexane dilution (10 wt%; 29.0 g) as a positive raw material therein, and continue stirring for 3 minutes to obtain a colorless transparent solution. . This was taken out of the glove box, and the entire amount of the content was put into the above-mentioned TOPO while keeping the argon atmosphere, and the coordinating organic compound and the positive raw material were mixed in advance.

On the other hand, similarly, in a glove box, tri-n-butylphosphine (116.6) was used as a solvent.
g) is dispensed into a 300 ml Erlenmeyer flask, hexamethyldisylthian (1.46 g) is charged as a negative raw material therein, and stirring is continued for 3 minutes to obtain a colorless transparent solution. This is taken out from the glove box, and the entire amount of the contents is attached to the row 15 portion shown in FIG. (2) Production of Cadmium Sulfide Ultrafine Particles by Flow Method In FIG. 1, the temperature settings of the temperature control parts corresponding to the preheating device 8, the preheating device 20, the reaction heating device 21, and the aging heating device 26 are each set to 300 ° C. , 20
℃, 300 ℃, and 300 ℃. Further, the product temperature adjusting device 27 is set to 60 ° C. near the outlet of the reaction liquid phase. The liquid feed pump 5 was 8.9 mL / min, and the liquid feed pump 18 was 1.
Each of them is driven with a capacity of 2 mL to start liquid transfer. Figure 1
At the portion corresponding to the point 22 inside the reactor 7 in
PO, that is, the coordinating organic compound, the positive raw material, and the negative raw material merge to start the reaction. The yellow reaction mixture containing cadmium sulfide ultrafine particles is collected in a glass 1000 mL screw cap bottle corresponding to the product storage tank 25. (3) Concentration of Cadmium Sulfide Ultrafine Particles In order to concentrate the obtained cadmium sulfide ultrafine particles, 13 g of the reaction liquid phase in a glass 1000 mL screw cap bottle corresponding to the above product storage tank 25 was fractionated. After adding 45 mL of dry methanol and stirring for 5 minutes, a suspension containing a yellowish white precipitate is obtained. 30m of this suspension
Transfer to 2 L vials and centrifuge at 3000 rpm for 15 minutes. After centrifuging, the supernatant was discarded, and toluene that had been distilled was added to the remaining precipitate in a nitrogen atmosphere, and the mixture was stirred for 3 minutes for washing, and this washed solution was washed with dry methanol 3
After adding 0 mL and stirring for 5 minutes, a suspension containing a yellowish white precipitate is obtained. The entire suspension is transferred to a 30 mL vial and centrifuged at 3000 rpm for 10 minutes. After centrifugation, the supernatant was discarded, the remaining precipitate was sprayed with dry nitrogen gas to predry it, and then the precipitate was washed at room temperature for 1 hour.
Vacuum dry for 5 hours. In this way, about 80 mg of concentrated cadmium sulfide ultrafine particles are obtained. Comparative Example 1 [Distribution production of cadmium sulfide ultrafine particles by the hot soap method] Tri-n-, which is put into the tank 1 in Example 1,
Butylphosphine and dimethylcadmium hexane diluted solution were put into the tank 15, and the liquid sending pump 5 was 7.1 mL / min.
Cadmium sulfide ultrafine particles were prepared in the same manner as in Example 1 except that the liquid feed pump 18 was driven at a capacity of 3.0 mL / min, and the positive raw material and the negative raw material were simultaneously supplied to the reactor 7 through the flow path 19. When synthesized, dimethylcadmium discharged from the liquid feed pump 18 and hexamethyldisylthiane react by being heated by heat transfer, and react with each other to form bulk cadmium sulfide near the entrance of the reactor 7, which causes blockage. However, it is impossible to continue the reaction any further.

[0034]

Industrial Applicability According to the production method of the present invention, ultrafine particles can be stably produced in a large amount without causing an undesired pre-reaction before the semiconductor raw material enters the reactor. Further, in a continuous reaction, it is possible to easily control the use ratio of two kinds of raw materials, and it is possible to produce compound semiconductor ultrafine particles having properties suitable for various uses.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of a manufacturing apparatus of a hot soap method.

[Explanation of symbols]

1 rowing 2-coordinating organic compound 3 heat retaining device 4 channels 5 Liquid feed pump 6 channels 7 reactor 8 Preheating device Raw material tank containing 9 positive elements 10 Positive raw materials 11 flow paths 12 Liquid feed pump 13 channels 14 Preliminary temperature controller 15 rowing 16 Negative raw material 17 channels 18 Liquid feed pump 19 channels 20 Preheating device 21 Reaction heating equipment 22 points 23 Reaction liquid phase 24 Reaction liquid flow path 25 product storage 26 Aging heating device 27 Product temperature controller 28 points

Claims (6)

[Claims] 1. A method for producing compound semiconductor ultrafine particles by a hot soap method using a tubular flow reactor,
Raw materials containing elements of groups 11 to 13 of the periodic table and fifteenth
A method for producing ultrafine particles of a compound semiconductor, which comprises independently supplying a raw material containing an element of group -17 to a reactor. 2. A raw material containing a Group 11 to 13 element,
The method for producing compound semiconductor ultrafine particles according to claim 1, wherein the compound semiconductor ultrafine particles are premixed with a coordinating organic compound and then supplied to a reactor. 3. A coordinating organic compound and a raw material containing a Group 11 to 13 element are mixed in advance to obtain a mixture and a first group.
The method for producing compound semiconductor ultrafine particles according to claim 2, wherein a raw material containing a Group 5 to 17 element is mixed. 4. The semiconductor ultrafine particles are selected from the group 11-17 compound semiconductor ultrafine particles, the group 12-16 compound semiconductor ultrafine particles, and the group 13-15 compound semiconductor ultrafine particles. 5. A method for producing compound semiconductor ultrafine particles according to any one of 1. 5. A raw material containing a Group 11 to 13 element,
The method for producing compound semiconductor ultrafine particles according to claim 1, wherein the supply ratios of the raw materials containing the Group 15 to 17 elements are changed independently. 6. A method for producing ultrafine compound semiconductor particles by a hot soap method using a tubular reactor, comprising: a raw material containing an element of groups 11 to 13 of the periodic table;
A method for producing compound semiconductor ultrafine particles, which comprises mixing raw materials containing a Group 17 element in the presence of a coordinating organic compound.