JP2003286292A - Semiconductor ultrafine particle and filmy molded product containing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor ultrafine particles having good solubility in a solvent and dispersibility in a polymer, and simultaneously having excellent film-forming properties and light absorption/emission characteristics controlled by a quantum effect of semiconductor crystals. <P>SOLUTION: The semiconductor ultrafine particles are formed by bonding alkylene glycol residues to surfaces of the semiconductor crystals through oxygen atoms in functional groups expressed by general formula (1) (R<SB>1</SB>and R<SB>2</SB>are each H, hydroxy, an alkyl which may be substituted and has carbon atoms of 8 or less, an aryl, an alkoxy, a trialkylsilyl or a halogen, and are similar to or different from each other). <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to ultrafine semiconductor particles and a thin film-shaped compact containing the same. For more information,
Novel semiconductor ultrafine particles having controlled absorption or emission characteristics by the quantum effect of the semiconductor crystal, good solubility in a solvent, dispersibility in a polymer, and excellent coating property, and a thin film containing the same The present invention relates to a molded product, and to a new material applicable as various optical materials.

[0002]

2. Description of the Related Art Semiconductor nanocrystals (Nanocrysta)
In the semiconductor ultrafine particles such as l), the energy levels are separated from each other by the quantization of the energy levels, and they are controlled as a function of the crystal grain size. Therefore, in the semiconductor ultrafine particles, the peak position of the exciton (exciton) absorption band, which appears at a slightly lower energy than the absorption edge on the long wavelength side of the fundamental absorption of the semiconductor crystal, corresponds to the particle size of the semiconductor ultrafine particles. It can be controlled by changing it, and exhibits electromagnetic wave absorption and generation ability (hereinafter referred to as absorption and emission ability) different from that of bulk, and therefore, it is expected to be used as a light emitting material or a memory material.

As a method for producing semiconductor ultrafine particles, a conventional vacuum production process such as molecular beam epitaxy (MB) is used.
E method), metal organic chemical vapor deposition method (MOVPE method), atomic layer epitaxy method (ALE method), and the like.
Although a product of high purity can be obtained by such a vacuum manufacturing process, the ultrafine particles produced can only be obtained in a state of firmly adhering to the substrate and cannot be freely dispersed and used in a medium such as a solvent or a polymer.

[0004] Applications of the characteristics of semiconductor ultrafine particles include blending with a polymer or the like to form a thin film, a display panel, a light emitting diode, a super resolution film of an optical disk,
Various things such as an optical waveguide can be considered. Development of ultrafine semiconductor particles with good dispersibility in organic solvents and polymers and excellent coating properties while maintaining absorption and emission ability controlled by quantum size effect for application to these materials Is essential.

A method for synthesizing semiconductor crystal particles in which an organic ligand expected to have good dispersibility in a polymer or an organic solvent is bonded to the surface has been reported (Non-Patent Document 1). The semiconductor crystal particles obtained by this method have a structure in which an organic ligand such as trioctylphosphine oxide (hereinafter abbreviated as TOPO) is bonded to the surface of a compound semiconductor crystal particle such as cadmium selenide (CdSe). It not only has excellent solubility in organic solvents such as toluene and methylene chloride, but also has the characteristic that the particle size distribution is controlled to be extremely narrow. However, the semiconductor crystal particles obtained by this method are TOP particles with a small intermolecular cohesive force.
Since it is considered that it is covered with an alkyl group such as the octyl group of O, it does not disperse in an aqueous solvent such as alcohol, and it is difficult to form a thin film molded article having both transparency and mechanical strength by itself. is there. Furthermore, an acrylic resin represented by polymethylmethacrylate (commonly called PMMA),
Insufficient dispersibility at high particle concentration in a general-purpose amorphous resin having practical heat resistance deformation such as styrene resin represented by polystyrene or aromatic polycarbonate resin represented by bisphenol A polycarbonate. Therefore, there is a drawback that an opaque polymer composition is provided.

Further, it has been reported that the peak emission intensity of the emission band was increased to about 20 times by substituting the primary allylamine for TOPO coordinated to CdSe (Non-patent document 2). It can be said that the amino group is a ligand that enhances the emission intensity, but in the case of alkylamines and alkenylamines, the particle surface is covered with the alkyl group or the alkenyl group as in TOPO, so that the solubility in an aqueous solvent, There is a problem that the dispersibility in the polymer and the coating property are not sufficient.

[Non-Patent Document 1] J. E. J. Bowen Katari et al., “Journal of Physical Chemistry (J. Phy
s. Chem. ) ”, (USA), Vol. 98, 1994,
p. 4109-4117

[Non-patent document 2] Dmitry buoy. Talapine (Dmit
ri V. Talapin) et al., "Nano Letters (NANO LETTERS)", (USA), Volume 1, 2
001, p. 207-211

[0007]

The present invention has been made in view of the above circumstances, and an object thereof is to provide a semiconductor ultrafine particle having good dispersibility in an organic solvent or a polymer and excellent coatability. In offer.

[0008]

Means for Solving the Problems As a result of extensive studies conducted by the present inventor to achieve the above object, a polyalkylene glycol residue typified by polyethylene glycol was substituted with a functional group represented by the following general formula (1). When bonded to the surface of a semiconductor crystal through an oxygen atom in the group, it is possible to enhance the light emitting ability of the semiconductor crystal, and to impart good solubility / dispersibility to an organic solvent or polymer, and after dissolution in an organic solvent. The present invention has been accomplished by finding that an optically transparent thin film shaped article can be provided by spin coating or the like.

That is, the first gist of the present invention resides in semiconductor ultrafine particles comprising a polyalkylene glycol residue bonded to the surface via an oxygen atom in the functional group represented by the general formula (1). .

[0010]

[Chemical 3]

(In the general formula (1), R ¹ and R ² are each a hydrogen atom, a hydroxyl group, an optionally substituted alkyl group having 8 or less carbon atoms, an aryl group, an alkoxyl group and a trialkylsilyl group. A group and any one selected from a halogen atom, and R ¹ and R ² may be the same or different.) The second gist of the present invention is a thin film-shaped molded product containing the above-mentioned semiconductor ultrafine particles. ,.

A third aspect of the present invention relates to n-phosphonoalkyltriethylene glycol ethers represented by the following general formula (2), which give such semiconductor ultrafine particles a high luminous ability and an excellent coating property. Exist.

[0013]

[Chemical 4]

(In the general formula (2), R represents a hydrogen atom or an alkyl group having 7 or less carbon atoms, and n represents a natural number of 20 or less.)

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION [Polyalkylene Glycol Residue] The polyalkylene glycol residue in the present invention is a polymer represented by the following general formula (3).

[0016]

Embedded image — (R ³ O) m—R ⁴ (3)

(In the general formula (3), R ³ is an alkylene group having 2 to 6 carbon atoms, R ⁴ is a hydrogen atom and 1 carbon atom.
10 represents a structure arbitrarily selected from the group consisting of an alkyl group having 10 to 10, an aryl group having 10 or less carbon atoms, and an acyl group having 2 to 5 carbon atoms, and m represents a natural number of 50 or less. As specific examples of R ³ in the general formula (3), ethylene group, n-propylene group, isopropylene group, n-butylene group, isobutylene group, n-pentylene group, cyclopentylene group, n-hexylene group, Cyclohexylene group and the like, from the viewpoint of solubility in an aqueous solvent, preferably an ethylene group, n-propylene group, isopropylene group, an alkylene group having 2 to 4 carbon atoms such as n-butylene group, more preferably An alkylene group having 2 or 3 carbon atoms such as an ethylene group, an n-propylene group and an isopropylene group is used, most preferably an ethylene group. In the general formula (3), plural kinds of R ³ may be mixed in one residue, and the copolymerization order (sequence) in this case is not limited.

Specific examples of the alkyl group used for R ⁴ in the general formula (3) include methyl group, ethyl group and n-
Propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, vinyl group, benzyl group, vinylbenzyl group, etc. From the viewpoint of solubility in a solvent, preferably a methyl group, an ethyl group,
An alkyl group having 3 or less carbon atoms, such as an n-propyl group and an isopropyl group, more preferably a methyl group or an ethyl group,
Most preferably the methyl group is used. Specific examples of the aryl group used for R ⁴ include phenyl group, toluyl group (monomethylphenyl group), dimethylphenyl group,
Ethylphenyl group, isopropylphenyl group, 4-te
Examples thereof include an rt-butylphenyl group, a vinylphenyl group, a pyridyl group, a monomethylpyridyl group and a dimethylpyridyl group. From the viewpoint of solubility in an aqueous solvent, a phenyl group or a pyridyl group is preferably used. Specific examples of the acyl group used for R ⁴ include an acetyl group, an acryloyl group, a methacryloyl group, a crotonoyl group and a maleoyl group, and the acetyl group is preferably used from the viewpoint of solubility in an aqueous solvent. It

Among the specific structures of R ^{4 shown} above, vinyl group, vinylbenzyl group, vinylphenyl group,
Acryloyl group, methacryloyl group, crotonoyl group,
When a polymerizable group such as a maleoyl group is used, the semiconductor ultrafine particles of the present invention may acquire copolymerizability with, for example, radically polymerizable monomers or ionically polymerizable monomers. The natural number m in the general formula (3) is preferably 40 or less,
It is more preferably 30 or less, still more preferably 20 or less, preferably 10 or less, particularly preferably 5 or less from the viewpoint of solubility.

As a particularly preferred structure of the general formula (3),
Triethylene glycol residue (R ³ is an ethylene group, m =
3), more preferred is a triethylene glycol monoalkyl ether residue in which R ⁴ is a methyl group or an ethyl group, and most preferred is a triethylene glycol monomethyl ether residue in which R ⁴ is a methyl group ( Hereinafter, it is abbreviated as MTEG residue).

[Functional Group Represented by General Formula (1)] In the present invention, the above polyalkylene glycol residue is a semiconductor crystal through an oxygen atom in the functional group represented by the following general formula (1). It is characterized by being bonded to the surface.

[0022]

[Chemical 6]

In the general formula (1), R ¹ and R ² are each a hydrogen atom, a hydroxyl group, or a carbon number 8 which may have a substituent.
It represents any one selected from the following alkyl groups, aryl groups, alkoxyl groups and trialkylsilyl groups, and halogen atoms, and R ¹ and R ² may be the same or different. Examples of the substituent in this case include a halogen atom, a nitro group, a hydroxyl group, a carboxyl group and the like.

By utilizing the functional group represented by the general formula (1), the luminous ability of the semiconductor ultrafine particles after coordination is remarkably improved. It is considered that this is because the oxygen atom in the functional group represented by the general formula (1) has a strong coordination power with the transition metal element existing on the semiconductor crystal surface. Although the actual bond structure of this strong coordinating force is not clear, the existence of, for example, a coordinate bond of an oxygen atom is estimated.

When R ¹ and R ² in the functional group represented by the general formula (1) each contain a carbon atom, the carbon atom is coordinated so that steric hindrance does not occur during coordination with the semiconductor nanoparticles. More preferably, the number is 5 or less. R
Specific examples of preferable functional groups of ¹ and R ² include a hydrogen atom, an alkyl group such as a hydroxyl group, a methyl group, an ethyl group and a butyl group, an alkoxyl group such as a methoxyl group, an ethoxyl group and a butoxyl group, and a trimethylsilyl group and the like. Examples thereof include alkylsilyl groups, halogen atoms such as fluorine atom, chlorine atom and bromine atom. Of these, in terms of coordination force to the semiconductor crystal is more preferable that at least one of R ¹ and R ² is a hydroxyl group, and most preferably R ¹ and R ² are both hydroxyl groups.

[Linking group of polyalkylene glycol residue and functional group represented by general formula (1)] In the present invention,
The compound connecting the polyalkylene glycol residue and the functional group represented by the general formula (1) can be arbitrarily selected. Specific examples include an alkylene group, an alkenylene group, an alkynylene group, a compound containing an ether bond, an ester bond, an amide bond, a carbonyl group, an amino group, a thiocarbonyl group, and the like in their carbon chains, and a hydrogen atom thereof. Examples thereof include compounds in which one or more are substituted with a halogen atom, a nitro group, a hydroxyl group, a carboxyl group, an alkyl group, an alkoxyl group, an aryl group and the like. Among these, an alkylene group and an alkenylene group are preferably used. In particular, an alkylene group having a carbon chain of 6 or more,
Preferably, the alkylene group having a monomolecular chain of 6 to 20 is most preferable because it may have an effect of protecting the semiconductor crystal from the outside and stabilizing its light absorption and emission characteristics.

Further, the polyalkylene glycol residue may be directly bonded to the functional group represented by the general formula (1). Specifically, the compound represented by the following general formula (5) is
Ultrafine semiconductor particles bonded to the surface of a semiconductor crystal are preferable because they have excellent light emission characteristics and excellent compatibility with resins.

[0028]

[Chemical 7]

In the general formula (5), R is a hydrogen atom or an alkyl group having 7 or less carbon atoms, n is a natural number of 20 or less, and r is 2 or more and 10 or less, preferably 5 or less. The compound represented by the general formula (5) is specifically 3,6,9-trioxaalkylphosphonic acid (2- [2- (2-alkoxyethoxy) ethoxy] ethylphosphonic acid) (n = 2 , R =
2), compounds such as n-phosphonoalkyltriethylene glycol ether (r = 3) are exemplified. [N-Phosphonoalkyltriethylene glycol ethers] As a molecular structure in which a polyalkylene glycol residue preferably used as a ligand for a semiconductor crystal in the present invention and a functional group represented by the general formula (1) are bonded. Are exemplified by n-phosphonoalkyl triethylene glycol ethers represented by the following general formula (2).

[0030]

[Chemical 8]

However, in the general formula (2), R represents a hydrogen atom or an alkyl group having 7 or less carbon atoms, and n represents a natural number of 20 or less. Examples of the alkyl group used as R are the same as those of R ⁴ in the general formula (3). In the general formula (2), the natural number n is preferably 1 to
17, more preferably 3 to 14, most preferably 6-1
When the value of the natural number n is 6 or more, the effect of protecting the semiconductor crystal from the outside and stabilizing its light absorption and emission characteristics may be seen. As a particularly preferred specific compound, 10-phosphonodecyl MTEG ether (10- [2- (2-methoxyethoxy) ethoxy] ethoxydecylphosphonic acid) of the following formula (4) is exemplified.

[0032]

[Chemical 9]

[Semiconductor Ultrafine Particles] The semiconductor ultrafine particles of the present invention are mainly composed of a semiconductor crystal as described below, and the polyalkylene glycol residue is bonded to the surface thereof. Therefore, the semiconductor ultrafine particles of the present invention contain the semiconductor crystal and the polyalkylene glycol residue bonded to the surface thereof as essential components.

The semiconductor crystal used in the present invention preferably has an exciton absorption / emission band controlled by the quantum effect in its absorption / emission spectrum. The absorption and emission wavelength range that is particularly useful for application is light in the far ultraviolet to infrared region,
Usually 150 to 10,000 nm, preferably 180 to 80 nm
00 nm, more preferably 200 to 6000 nm, and most preferably 220 to 4000 nm. The wavelength of the exciton absorption / emission band phenomenologically depends on the grain size of the semiconductor crystal.

The semiconductor crystal may be a semiconductor single crystal, a mixed crystal in which a plurality of semiconductor crystal compositions are phase-separated, or a mixed semiconductor crystal in which phase separation is not observed, and may have a core-shell structure described later. The particle size of such a semiconductor crystal is usually 0.5 to 20 nm as a number average particle size, and preferably 1 to 15 n in terms of controllability of absorption and emission wavelength by quantum effect.
m, more preferably 2 to 12 nm, most preferably 3 to
10 nm. A numerical value measured from a transmission electron microscope (TEM) observation image of a given semiconductor ultrafine particle is used for determining the number average particle diameter. That is, the diameter of a circle having the same area as the observed particle image of the semiconductor crystal is defined as the particle size of the particle image. The number average particle diameter is calculated, for example, by a known statistical processing method of image data using the thus determined particle diameter. The number of particle images of the semiconductor crystal used in the statistical processing (the number of statistically processed data) is acceptable. Naturally, it is desirable that the number is as large as possible, and in the present invention, the number of randomly selected particle images in terms of reproducibility is at least 50, preferably 80 or more, more preferably 100 or more. . If the number average particle size is too large, the cohesiveness may extremely increase or the controllability of exciton absorption / emission due to the quantum effect may decrease, while if the number average particle size is too small, the semiconductor crystal particles may become independent. In some cases, the function as a crystal (for example, the formation of a band structure that gives luminescence) may be lowered, or the isolation yield during production may be extremely lowered, which is not preferable. The atomic number of the element contained in the semiconductor crystal is small and TE
When it is difficult to obtain a contrast due to an electron beam in M observation, even if the composition analysis results such as elemental analysis are combined with the observation of semiconductor ultrafine particles by an atomic force microscope (AFM) or the light scattering in a solution or the neutron scattering measurement, The diameter can be estimated.

Although there is no limitation on the grain size distribution of the semiconductor crystal,
When the exciton absorption / emission band of the semiconductor crystal is used, the absorption / emission band wavelength width can be changed by changing the distribution. When it is necessary to narrow the wavelength width, the particle size distribution is narrowed, but usually the standard deviation is within ± 40%, preferably within ± 30%, more preferably within ± 20%, and most preferably. Is within ± 10%.
If the particle size distribution exceeds the range of this standard deviation, it becomes difficult to sufficiently achieve the purpose of narrowing the wavelength width of the exciton absorption / emission band.

[Composition of Semiconductor Crystal] The composition example of the semiconductor crystal is represented by a composition formula: C, Si, Ge, Sn, etc. 15
Group element element simple substance, periodic table group 16 element element such as Se or Te, compound consisting of a plurality of periodic table group 14 element such as SiC, SnO ₂ , Sn (II) Sn (IV) S ₃ , SnS ₂ , S
nS, SnSe, SnTe, PbS, PbSe, PbT
compounds of Group 14 elements of the periodic table, such as e, and elements of Group 16 of the periodic table, BN, BP, BAs, AlN, AlP, AlA
s, AlSb, GaN, GaP, GaAs, GaSb,
Periodic table of InN, InP, InAs, InSb, etc. 13th
Compounds of Group 15 elements with Group 15 elements of the periodic table (or III
-V compound semiconductor), Al ₂ S ₃ , Al ₂ Se ₃ , Ga ₂
S ₃ , Ga ₂ Se ₃ , Ga ₂ Te ₃ , In ₂ O ₃ , In ₂ S ₃ ,
Compounds of Group 13 elements of the Periodic Table and Group 16 elements of the Periodic Table such as In ₂ Se ₃ , In ₂ Te ₃ , TlCl, TlBr, Tl
Compounds of periodic table group 13 elements such as I and periodic table group 17 elements, ZnO, ZnS, ZnSe, ZnTe, CdO,
CdS, CdSe, CdTe, HgS, HgSe, Hg
A compound of a group 12 element of the periodic table such as Te and a group 16 element of the periodic table (or II-VI group compound semiconductor), As ₂ S ₃ ,
As ₂ Se ₃ , As ₂ Te ₃ , Sb ₂ S ₃ , Sb ₂ Se ₃ , Sb
₂ Te ₃ , Bi ₂ S ₃ , Bi ₂ Se ₃ , Bi ₂ Te ₃ and other compounds of the periodic table group 15 element and the periodic table group 16 element, Cu ₂
O, Cu ₂ Se, etc. Periodic Table Group 11 elements and Periodic Table 16th
Compounds with group elements, CuCl, CuBr, CuI, Ag
Periodic Table Group 11 elements such as Cl and AgBr and Periodic Table 17
Compounds with group elements, compounds of group 10 elements of the periodic table and elements of group 16 of the periodic table such as NiO, compounds of group 9 elements of the periodic table and groups 16 elements of the periodic table such as CoO and CoS, Fe ₃
Iron oxides such as O ₄ , compounds of periodic table group 8 elements and periodic table group 16 elements such as FeS, compounds of periodic table group 7 elements and periodic table group 16 elements such as MnO, MoS ₂ A compound of an element of Group 6 of the periodic table with an element of Group 16 of the periodic table, such as WO ₂ ,
VO, VO ₂ , Ta ₂ O ₅ and other compounds of periodic table group 5 element and periodic table group 16 element, TiO ₂ , Ti ₂ O ₅ , Ti ₂ O
₃ , titanium oxides such as Ti ₅ O ₉ (the crystal type may be any of rutile type, rutile / anatase mixed crystal type and anatase type), ZrO ₂ etc. CdCr ₂ compound with group element, compound with group 2 element of periodic table such as MgS, MgSe, etc., CdCr _{2
O 4, CdCr 2 Se 4,} CuCr 2 S 4, HgCr 2 Se 4
And chalcogen spinels such as BaTiO _{3 and the} like. In addition, G. Schmid et al .; Adv. Ma
ter. , BN, 75 (BF2) 15F15, reported in Vol. 4, p. 494 (1991); Fens
ke et al .; Angew. Chem. Int. Ed. Eng
l. 29, p. 1452 (1990), a semiconductor cluster having a definite structure, such as Cu146Se73 (triethylphosphine) 22, is also exemplified.

Of these, those that are practically important are, for example,
For example, Si, Ge, etc. Group 14 simple substance, SnO₂, SnS₂, Sn
S, SnSe, SnTe, PbS, PbSe, PbTe
Of elements of Group 14 of the periodic table and elements of Group 16 of the periodic table
Objects, GaN, GaP, GaAs, GaSb, InN, I
Semiconductors for III-V compounds such as nP, InAs, InSb
Body, Ga₂O₃, Ga₂S₃, Ga₂Se₃, Ga₂Te₃, I
n₂O₃, In₂S₃, In ₂Se₃, In₂Te₃Periodic table of etc.
A compound of a Group 13 element and a Group 16 element of the periodic table, Zn
O, ZnS, ZnSe, ZnTe, CdO, CdS, C
dSe, CdTe, HgO, HgS, HgSe, HgT
II-VI group compound semiconductors such as e, As₂O₃, As₂S₃, A
s₂Se₃, As₂Te₃, Sb₂O₃, Sb₂S₃, Sb₂S
e₃, Sb₂Te₃, Bi₂O₃, Bi₂S₃, Bi₂Se₃,
Bi₂Te₃Periodic Table Group 15 elements and Periodic Table Group 16 elements
Compound with element, Fe₃O_FourOxides such as FeS and the cycle of FeS
A compound of a Group 8 element of the periodic table and a Group 16 element of the periodic table,
Titanium oxides and ZrO₂Periodic table of the 4th group elements and periodic table
Periodic table of compounds with Group 16 elements, MgS, MgSe, etc.
It is a compound of a Group 2 element and a Group 16 element of the periodic table.

Among these, Si, Ge, SnO ₂ ,
GaN, GaP, In ₂ O ₃ , InN, InP, Ga
₂ O ₃ , Ga ₂ S ₃ , In ₂ O ₃ , In ₂ S ₃ , ZnO, Zn
S, CdO, CdS, the titanium oxides, ZrO ₂ , M
Since gS has a characteristic of having a high refractive index and does not contain a highly toxic negative element, it is preferable in terms of resistance to environmental pollution and safety to living organisms. From this viewpoint, SnO ₂ , In ₂ O ₃ ,
Compositions not containing highly toxic positive elements such as ZnO, ZnS, the above-mentioned titanium oxides and ZrO ₂ are more preferable. Among them, ZnO or the above-mentioned titanium oxides (rutile type crystals are particularly preferable for high refractive index). Most preferred are metal oxide semiconductor crystals such as (preferably) and ZrO ₂ . The long-wavelength side absorption edge of the rutile-type titanium oxide crystal particles is usually around 400 nm in the bulk state, but by setting the number average particle diameter of the crystal particles to the above range, the long-wavelength side absorption edge wavelength becomes shorter It becomes possible to shift to the wavelength, and there may be an advantage that the colorlessness in the visible region is improved. In addition, colored semiconductor crystals having absorptivity in the visible region, such as iron oxides and cobalt blue (a complex oxide of Co and Al), are important for use as coloring materials such as pigments.

GaN, GaP, GaAs, InN, InP having an emission band in the visible region which is practically important and in the vicinity thereof
III-V compound semiconductors such as ZnO, ZnS, ZnS
e, ZnTe, CdO, CdS, CdSe, CdTe,
II-VI group compound semiconductors such as HgO and HgS, Si, G
e, In ₂ O ₃ , In ₂ S _3, etc. are important, and among them, GaN and G are preferable because of the controllability of the grain size of the semiconductor crystal and the luminous ability.
III-V group compound semiconductors such as aP, GaAs, InN, InP, ZnO, ZnS, ZnSe, ZnTe, Cd
II-VI group compound semiconductors such as O, CdS, and CdSe, and ZnSe, CdS, CdSeInP, and GaP are particularly preferably used for this purpose. In the composition of any of the semiconductor crystals exemplified above, a small amount of a doping substance (meaning an impurity intentionally added) may be added, for example, as A
l, Mn, Cu, Zn, Ag, Cl, Ce, Eu, T
Elements such as b, Er and Tm may be added.

[Core-Shell Type Semiconductor Crystal] The semiconductor crystal is, for example, A. R. Kortan et al .; Am. Ch
em. Soc. , 112, p. 1327 (1990) or US Pat. No. 5,985,173 (1999), as disclosed in US Pat. No. 5,985,173, from the core and the shell for the purpose of improving the electronic excitation characteristics of the semiconductor crystal. Such a so-called core-shell structure may improve the stability of the quantum effect of the semiconductor crystal forming the core, and thus may be suitable for applications using the exciton absorption / emission band. In this case, it is generally effective to form an energy barrier by using a semiconductor crystal composition of the shell having a band gap (band gap) larger than that of the core. It is presumed that this is due to a mechanism that suppresses the influence of an undesired surface level or the like due to the influence of the external environment or the crystal lattice defect on the crystal surface.

The composition of the semiconductor crystal preferably used for such a shell depends on the band gap of the core semiconductor crystal, but the band gap in the bulk state has a temperature of 300K.
At 2.0 eV or more, eg B
III-V group compound semiconductors such as N, BAs, GaN and GaP, ZnO, ZnS, ZnSe, ZnTe, CdO, C
A II-VI group compound semiconductor such as dS, a compound of an element of Group 2 of the periodic table and an element of Group 16 of the periodic table such as MgS or MgSe, and the like are preferably used. Among these, the semiconductor crystal composition which becomes a more preferable shell is III, such as BN, BAs, and GaN.
-Group V compound semiconductor, ZnO, ZnS, ZnSe, Cd
1. The II-VI group compound semiconductor such as S, the band gap in the bulk state of the compound of the periodic table group 2 element such as MgS, MgSe and the like, and the group 16 element of the periodic table at a temperature of 300K.
More than 3 eV, most preferably B
N, BAs, GaN, ZnO, ZnS, ZnSe, Mg
The band gap in the bulk state of S, MgSe, etc. is at temperature 3
It is 2.5 eV or more at 00K, and ZnS is most preferably used in chemical synthesis. A particularly preferred combination example of the core / shell composition used for the semiconductor crystal in the present invention is expressed by a composition formula, CdSe / Zn.
S, CdSe / ZnO, CdSe / ZnSe, CdSe
/ CdS, CdS / ZnS, CdS / ZnO, InP /
ZnS etc. are mentioned.

[Auxiliary Ligand] The semiconductor crystal ultrafine particles of the present invention have an auxiliary ligand other than the above polyalkylene glycol residue on the surface thereof for the purpose of suppressing and stabilizing undesired effects such as aggregation. You may have it. Examples of such ligands are given below. (A) Sulfur-containing compound: mercaptoethane, 1-mercapto-n-propane, 1-mercapto-n-butane, 1-mercapto-n-hexane, mercaptocyclohexane, 1-mercapto-n-octane, 1-mercapto Mercaptoalkanes such as -n-decane, thiophenol, 4-methylthiophenol, 4-tert-butylthiophenol, thiophenol derivatives such as 4-hydroxythiophenol, dimethyl sulfoxide, diethyl sulfoxide, dibutyl sulfoxide, dihexyl sulfoxide, dioctyl Dialkyl sulfoxides such as sulfoxide and didecyl sulfoxide, dimethyl disulfide, diethyl disulfide, dibutyl disulfide, dihexyl disulfide, dioctyl disulfide, didecyl disulfide Dialkyl disulfides such as de, thiourea, a compound having a thiocarbonyl group such as thioacetamide, sulfur-containing aromatic compounds such as thiophene.

(B) Phosphorus-containing compound: trialkylphosphines such as triethylphosphine, tributylphosphine, trihexylphosphine, trioctylphosphine, tridecylphosphine, tris (3-hydroxypropyl) phosphine, triethylphosphine oxide, tributyl Trialkylphosphine oxides such as phosphine oxide, trihexylphosphine oxide, trioctylphosphine oxide (abbreviated TOPO), tridecylphosphine oxide, tris (3-hydroxypropyl) phosphine oxide, and aromatics such as triphenylphosphine and triphenylphosphine oxide Group phosphines or aromatic phosphine oxides.

(C) Nitrogen-containing compound: A nitrogen-containing aromatic compound such as pyridine or quinoline, trimethylamine,
Tertiary amines such as triethylamine, tributylamine, trihexylamine, trioctylamine, tridecylamine, triphenylamine, methyldiphenylamine, diethylphenylamine, tribenzylamine, diethylamine, dibutylamine, dihexylamine, dioctylamine, didecylamine. , Diphenylamine,
Secondary amines such as dibenzylamine, diethanolamine, propylamine, butylamine, hexylamine,
Primary amines such as octylamine, decylamine, dodecylamine, hexadecylamine, octadecylamine, phenylamine, benzylamine, 2-aminoethanol, carboxylic acid esters having an amino group such as nitrilotriacetic acid triethyl ester, and the like.

Of these exemplified auxiliary ligands, preferred are mercaptoethane, 1-mercapto-n-propane, 1-mercapto-n-butane and 1-mercapto-.
Carbon number 6 such as n-hexane and mercaptocyclohexane
Sulfur content of the following mercaptoalkanes, thiophenol derivatives such as thiophenol, 4-methylthiophenol and 4-tert-butylthiophenol, and dialkyl sulfoxides having a total carbon number of 8 or less such as dimethyl sulfoxide, diethyl sulfoxide and dibutyl sulfoxide. Compounds, tributylphosphine, trihexylphosphine, trioctylphosphine, etc. having a total carbon number of 24 or less, trialkylphosphine oxide, triethylphosphine oxide, tributylphosphine oxide, trihexylphosphine oxide, trioctylphosphine oxide, etc., having a total carbon number of 24 or less Phosphorus-containing compounds such as trialkylphosphine oxides and primary amines such as propylamine and hexadecylamine, among which mercaptoethane and 1-merca Mercaptoalkanes having 4 or less carbon atoms such as ton-butane, sulfur-containing compounds such as thiophenol, 4-methylthiophenol, thiophenol derivatives such as 4-tert-butylthiophenol, tributylphosphine, trihexylphosphine, etc. Phosphorus-containing compounds such as trialkylphosphine oxides having a total carbon number of 18 or less, tributylphosphine oxide, trihexylphosphine oxide and the like, and trialkylphosphine oxides having a total carbon number of 18 or less are more preferable.

[Semiconductor Crystal Manufacturing Method] Any conventional method such as the following semiconductor crystal manufacturing method may be used. Although the vacuum manufacturing process may be used, the following three liquid phase methods are exemplified as suitable methods. (A) A method of allowing a raw material aqueous solution to exist as a reverse micelle in a non-polar organic solvent and growing crystals in the reverse micelle phase (hereinafter referred to as “reverse micelle method”). S. Zou
Int. J. Quant. Chem. , Volume 72, 4
39 (1999). A well-known reverse micelle stabilization technology can be used in a general-purpose reaction kettle, a relatively inexpensive and chemically stable salt can be used as a raw material, and it is performed at a relatively low temperature that does not exceed the boiling point of water. This method is suitable for production. However, the current state of the art may be inferior to the light emission characteristics as compared with the case of the hot soap method described below.

(B) A method of injecting a thermally decomposable raw material into a high temperature liquid-phase organic medium for crystal growth (hereinafter referred to as a hot soap method), which is reported in, for example, the above-mentioned document by Katari et al. Is the way. Compared with the above-mentioned reverse micelle method, semiconductor crystal particles excellent in particle size distribution and purity can be obtained, and the product is excellent in light emission characteristics and is usually soluble in an organic solvent. In order to desirably control the reaction rate of the crystal growth process in the liquid phase in the hot soap method, a coordinating organic compound having an appropriate coordinating force for a semiconductor constituent element is used as a liquid phase component (also serves as a solvent and a ligand). ) Is selected as. Examples of such a coordinating organic compound include the trialkylphosphines, the trialkylphosphine oxides, ω-aminoalkanes such as dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, and the dialkyl sulfoxides. Is mentioned. Of these,
The above-mentioned trialkylphosphine oxides such as TOPO and ω-aminoalkanes such as hexadecylamine are preferable. (C) A solution reaction involving semiconductor crystal growth similar to the hot soap method described above, but a method of performing an acid-base reaction at a relatively low temperature as a driving force has been known for a long time (for example, PA Jackson). ; J.Cryst.G
Rowth, 3-4, 395 (1968)). Such a method is sometimes called a sol-gel method and classified.

As the semiconductor raw material that can be used in the above three liquid phase production methods, a substance containing a positive element selected from Groups 2 to 15 of the periodic table and a negative element selected from Groups 15 to 17 of the periodic table The substance containing is mentioned. For example, in the hot soap method described above, organic metals such as dimethylcadmium and diethylzinc, and selenium simple substance dissolved in tertiary phosphines such as trioctylphosphine and tributylphosphine, and chalcogenide elements such as bis (trimethylsilyl) sulfide. A method of reacting a compound with TOPO is preferably used. In addition, for example, when zinc oxide is produced by the solution reaction of (c), L. Spa
nhel et al .; Am. Chem. Soc. , 113
The method of reacting zinc acetate with lithium hydroxide described in Vol. 2826 (1991) in ethanol is preferably used. When there are plural kinds of semiconductor raw material, they may be mixed in advance, or they may be injected individually into the reaction liquid phase. These raw materials may be used as a solution using an appropriate diluting solvent.

Examples of the positive element-containing compound used as a semiconductor raw material compound are dialkylated compounds of Group 2 elements of the periodic table such as diethyl magnesium and di-n-butyl magnesium, methyl magnesium chloride, methyl magnesium bromide and methyl iodide. Alkyl halides of Group 2 elements of the periodic table such as magnesium and ethynyl magnesium chloride, dihalides of Group 2 elements of the periodic table such as magnesium iodide, titanium tetrachloride (IV), titanium tetrabromide (IV), tetraiodide A halide of a Group 4 element of the periodic table, such as titanium (IV) chloride,
Vanadium dichloride (II), vanadium tetrachloride (IV), vanadium dibromide (II), vanadium tetrabromide (IV), vanadium diiodide (II), vanadium tetraiodide (IV), tantalum pentachloride ( V), tantalum pentabromide (V), tantalum pentaiodide (V) and the like, halides of elements of Group 5 of the periodic table,
Chromium (III) tribromide, chromium (III) triiodide, molybdenum (IV) tetrachloride, molybdenum (IV) tetrabromide, molybdenum (IV) tetraiodide, tungsten (IV) tetrachloride, tungsten tetrabromide (IV), etc. Periodic Table Group 6 element halides, manganese (II) dichloride, manganese dibromide (II), manganese diiodide (II), etc. Group 7 element halides, Iron chloride (II), iron trichloride (III), iron dibromide (I
I), iron (III) tribromide, iron (II) diiodide, iron (III) triiodide, etc., halides of Group 8 elements of the Periodic Table, cobalt dichloride (II), cobalt dibromide ( II), cobalt (II) diiodide, etc. Periodic Table Group 9 element halides, nickel dichloride (II), nickel dibromide (II), nickel diiodide (II), etc. Halides of group elements,
Halides of Group 11 elements of the periodic table such as copper (I) iodide, dimethyl zinc, diethyl zinc, di-n-propyl zinc, diisopropyl zinc, di-n-butyl zinc, diisobutyl zinc, di-n-hexyl zinc , Dicyclohexylzinc, dimethylcadmium, diethylcadmium, dimethylmercury (II), diethylmercury (II), dibenzylmercury (II), etc. dialkylated compounds of Group 12 elements of the periodic table, methylzinc chloride, methylzinc bromide, iodide Alkyl halides of Group 12 elements of the periodic table such as methylzinc, ethylzinc iodide, methylcadmium chloride, and methylmercury (II) chloride, zinc dichloride, zinc dibromide, zinc diiodide, cadmium dichloride, dichloride Cadmium bromide, cadmium diiodide, mercury (II) dichloride, zinc iodide chloride, cadmium chloride iodide, mercury (II) chloride iodide Bromide zinc iodide, 12 of the periodic table, such as bromide, iodide, cadmium bromide mercury iodide (II)
Group element dihalides, zinc acetate, cadmium acetate,
Carboxylic acid salts of group 12 elements of the periodic table such as cadmium 2-ethylhexanoate, oxides of group 12 elements of the periodic table such as cadmium oxide and zinc oxide, trimethylboron, tri-n
-Propylboron, triisopropylboron, trimethylaluminum, triethylaluminum, tri-n-
Butyl aluminum, tri-n-hexyl aluminum, trioctyl aluminum, tri-n-butyl gallium (III), trimethyl indium (III), triethyl indium (III), tri-n-butyl indium (I
II) trialkylated compounds of Group 13 elements of the periodic table, dimethyl aluminum chloride, diethyl aluminum chloride, di-n-butyl aluminum chloride, diethyl aluminum bromide, diethyl aluminum iodide, di-n-butyl gallium chloride (III ), Di-n-butylindium chloride (I
II) such as dialkyl monohalides of Group 13 elements of the periodic table, methylaluminum dichloride, ethylaluminum dichloride, ethylaluminum dibromide, ethylaluminum diiodide, n-butylaluminum dichloride, n-dichlorodichloride.
-Butylgallium (III), n-butylindium (III) dichloride, etc., Monoalkyl dihalides of Group 13 elements in the periodic table, boron trichloride, boron tribromide, boron triiodide, aluminum trichloride, triodor Aluminum iodide, aluminum triiodide, gallium (III) trichloride, gallium (III) tribromide, gallium (III) triiodide, indium (III) trichloride, indium (III) tribromide, indium triiodide (III), gallium (III) dichloride bromide, gallium (III) dichloride dichloride, gallium diiodide chloride (II
I), indium (III) dichloride dichloride, etc.
Group group trihalides, indium (III) acetate,
Carboxylates of Group 13 elements of the periodic table such as gallium (III) acetate, germanium (IV) tetrachloride, germanium (IV) tetrabromide, germanium (IV) tetraiodide, tin dichloride (I
I), tin (IV) tetrachloride, tin (II) dibromide, tin tetrabromide (I
V), tin (II) diiodide, tin (IV) tetrabromide, tin (IV) diiodide dichloride, tin (IV) tetraiodide, lead (II) dichloride, lead dibromide (II) ), Lead (II) diiodide, etc., Group 14 element halides, diphenylsilane, etc.
Group element hydrides and alkylates, trimethyl antimony (III), triethyl antimony (III), tri-n-
Butylantimony (III), Trimethylbismuth (II
I), triethylbismuth (III), tri-n-butylbismuth (III) and other trialkylated compounds of Group 15 elements of the periodic table, methylantimony dichloride (III), methylantimony dibromide (III), and diiodine. Methyl antimony oxide (II
I), ethyl antimony (III) diiodide, methyl bismuth (III) dichloride, ethyl bismuth (III) diiodide, etc. Monoalkyl dihalides of Group 15 elements of the Periodic Table, arsenic trichloride (III), tris Arsenic bromide (III), arsenic triiodide (III), antimony trichloride (III), antimony tribromide (III), antimony triiodide (III), bismuth trichloride (III), bismuth tribromide ( III), bismuth (III) triiodide, and the like, and trihalides of Group 15 elements of the periodic table.

In addition, germanium tetrachloride (IV), germanium tetrabromide (IV), germanium tetraiodide (IV), tin (II) dichloride, tin (IV) tetrachloride, tin (II) dibromide, Tin (IV) tetrabromide, tin (II) diiodide, tin (IV) tetrabromide, tin (IV) dichloride dichloride, tin (IV) tetraiodide, lead dichloride (I)
I), lead (II) dibromide, lead (II) diiodide and the like, halides of elements of Group 14 of the periodic table, and hydrides and alkylates of elements of Group 14 of the periodic table such as diphenylsilane S
It may be used as a raw material for ultrafine particles of a simple substance semiconductor of a Group 14 element of the periodic table such as i, Ge, and Sn.

Examples of the compound containing a negative element as a semiconductor raw material compound include nitrogen, phosphorus, arsenic, antimony, bismuth, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine, iodine, etc. Group element simple substance, ammonia, phosphine (PH3), arsine (AsH)
3), hydrides of elements of Group 15 of the Periodic Table of Elements such as stibine (SbH3), tris (trimethylsilyl) amine, tris (trimethylsilyl) phosphine, silylation of Group 15 elements of the Periodic Table of elements such as tris (trimethylsilyl) arsine, hydrogen sulfide , Hydrogen selenide, hydrogen telluride and other hydrides of Group 16 elements, bis (trimethylsilyl) sulfide, bis (trimethylsilyl) selenide and other silylates of Group 16 elements, sodium sulfide, sodium selenide, etc. Alkali metal salts of Group 16 elements of the periodic table, tributylphosphine sulfide, trihexylphosphine sulfide, trioctylphosphine sulfide, tributylphosphine selenide, trihexylphosphine selenide, trioctylphosphine selenide and other trialkylphosphines Chalcogenides, hydrogen fluoride,
Examples thereof include hydrides of elements of Group 17 of the periodic table such as hydrogen chloride, hydrogen bromide and hydrogen iodide, and silylated products of elements of Group 17 of the periodic table such as trimethylsilyl chloride, trimethylsilyl bromide and trimethylsilyl iodide. Of these, in terms of reactivity and stability / operability of the compound, phosphorus, arsenic, antimony, bismuth, sulfur, selenium, tellurium, iodine, and other elements of the periodic table group 15 to 17 elements, tris (trimethylsilyl) Periodic table No. 16 such as silylated compounds of Group 15 elements of the periodic table such as phosphine and tris (trimethylsilyl) arsine, hydrogen sulfide, hydrogen selenide, hydrogen telluride
Group 1 hydrides, bis (trimethylsilyl) sulfide, bis (trimethylsilyl) selenide, etc.
Alkyl metal salts of Group 16 elements such as silylated products of Group 6 elements, sodium sulfide, sodium selenide, tributylphosphine sulfide, trihexylphosphine sulfide, trioctylphosphine sulfide, tributylphosphine selenide, trihexylphosphine selenide , Trialkylphosphine chalcogenides such as trioctylphosphine selenide, trimethylsilyl chloride, trimethylsilyl bromide, silylated compounds of the periodic table group 17 elements such as trimethylsilyl iodide are preferably used, among which phosphorus, arsenic, antimony, sulfur, A simple substance of elements of Groups 15 and 16 of the periodic table such as selenium, a silylated product of an element of Group 15 of the periodic table such as tris (trimethylsilyl) phosphine, tris (trimethylsilyl) arsine, bis (trimethylsilyl) Sulfide, bis (trimethylsilyl) selenide, etc., silylation products of Group 16 elements of the Periodic Table, sodium sulfide, alkali metal salts of Group 16 elements, such as sodium selenide, tributylphosphine sulfide, trioctylphosphine sulfide, tributyl Trialkylphosphine chalcogenides such as phosphine selenide and trioctylphosphine selenide are particularly preferably used.

There is no limitation on the feed rate of the above-mentioned raw material compound to the reaction liquid phase in the hot soap method which is a particularly preferable liquid phase production method, but it is 0 when narrowing the particle size distribution of the generated semiconductor crystal ultrafine particles. It may be preferable to inject a predetermined amount in a short time of about 1 to 60 seconds. The appropriate crystal growth reaction time (residence time in the case of the flow method) after injection of the raw material solution varies depending on the semiconductor species, desired particle size or reaction temperature, but is typically 200 to
It is about 1 minute to 10 hours at a reaction temperature of about 350 ° C.

In such a hot soap method, isolation and purification are usually carried out after the completion of the semiconductor crystal growth reaction. As this method, the concentration of the liquid phase component or the precipitation method is suitable. A preferable typical procedure of the precipitation method is as follows. That is, after cooling to such an extent that the solidification temperature of the reaction liquid is not reached, toluene or hexane is added to suppress solidification at room temperature, and then a poor solvent for semiconductor ultrafine particles, such as methanol, ethanol, n-propanol, isopropyl alcohol. , N
-A procedure in which semiconductor ultrafine particles are precipitated by mixing with a lower alcohol such as butanol or water, and the ultrafine particles are separated by a physical means such as centrifugation or decantation. It is possible to further increase the degree of purification by redissolving the thus obtained precipitate in toluene, hexane or the like and repeating the procedure of precipitation and separation. The precipitation solvent may be a mixed solvent.

[Binding of Polyalkylene Glycol Residue to Semiconductor Crystal Surface] The semiconductor crystal obtained by any of the above-mentioned production methods has a coordination structure of the functional group represented by the general formula (1). There is no limitation on the method of binding the polyalkylene glycol by utilizing. An example thereof is a method of coordinating a polyalkylene glycol having a functional group represented by the general formula (1) (hereinafter abbreviated as PAG- (1)) on the surface of a semiconductor crystal. A ligand exchange reaction is possible in which semiconductor ultrafine particles having a coordinating organic compound such as TOPO obtained by the hot soap method on the surface are brought into contact with PAG- (1) in a liquid phase. In this case, if necessary, a solution using a solvent as described below may be used, and when PAG- (1) used is a liquid under the reaction conditions, PAG- (1) itself may be used as a solvent. A reaction type in which the solvent is not added is also possible.

Examples of such ligand exchange reaction conditions include X. Peng et al .; Angew. Chem. Int.
Ed. Engl. 36, p. 145 (1997), a method carried out in alcohols such as methanol. Bruchez Jr. Et al., Science,
281, page 2013 (1998), in a mixed solvent of dimethylsulfoxide and alcohols such as methanol, or C.I. W. Warren
Et al., Science, 281, 2016 (199)
According to the method described in 8), a method of performing it in a halogenated solvent such as chloroform can be used. In addition, the above X. Pe
ng et al .; Am. Chem. Soc. , 119, 7
As reported on page 019 (1997), semiconductor ultrafine particles having a coordinating organic compound such as trioctylphosphine oxide obtained by the hot soap method on the surface are used as weak coordinating compounds such as pyridine (usually A method of removing the coordinating organic compound by dispersing in a liquid phase containing a large excess amount of the solvent) is also applicable. That is, it is a two-step reaction consisting of a first step of removing a coordinating organic compound in a weakly coordinating compound such as pyridine, and then a second step of adding PAG- (1). In either method, the reaction solution may be heated or depressurized if necessary.

As the solvent used in the ligand exchange reaction, nitrogen-containing aromatic compounds such as pyridine, lutidine, collidine, or quinoline, halogenated methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, etc. Aromatic hydrocarbons such as alkyls, benzene, toluene, xylene, naphthalene, chlorobenzene and dichlorobenzene, alkanes such as n-pentane, n-hexane, cyclohexane, n-octane and isooctane, fats such as diethyl ether and tetrahydrofuran Group ethers, aliphatic ketones such as acetone and methyl ethyl ketone, ester solvents such as methyl acetate and ethyl acetate, alcohols such as methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol and ethylene glycol, phenol Phenols such as nor and cresol, and compounds having a hydroxyl group such as water, amide aprotons such as N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc) and N-methylpyrrolidone (NMP) Examples of the organic solvent include sulfoxides such as dimethyl sulfoxide, and water. These solvents may be mixed and used in any kind, combination and ratio depending on the necessity of adjusting the solubility of the semiconductor ultrafine particles and the product thereof.

In the above ligand exchange reaction, by controlling the amount of PAG- (1) used, a desired amount of PAG- (1) can be bonded to the semiconductor crystal surface. PAG- (1) in the semiconductor ultrafine particles of the present invention
The amount of binding of the
%) Is usually 0.1 to 100 wt%, preferably 1 to 100 wt%, more preferably 10 to 1 in terms of hydrophilicity.
The amount is 00 wt%, and most preferably 20 to 100 wt%. The weight percentage is measured by the nuclear magnetic resonance spectrum (NM
R), infrared absorption spectrum (IR), elemental analysis, or thermogravimetric analysis (TG) can be used for estimation.

The above-mentioned ligand exchange reaction is usually -10 to 2
It is carried out in a temperature range of about 50 ° C., and in order to avoid thermal deterioration of organic substances and incomplete exchange reaction, this temperature range is preferably 0.
To about 200 ° C, more preferably about 10 to 150 ° C,
Most preferably, it is about 20 to 120 ° C. On the other hand, the reaction time is usually 1 minute to 100 hours, preferably 5 minutes to 70 hours, more preferably 10 minutes to 50, although it depends on the raw materials and temperature.
Time, most preferably about 10 minutes to 30 hours. Further, in the ligand exchange reaction, there is no limitation on the order of adding the semiconductor ultrafine particles and PAG- (1) to the reaction solution.

The ligand exchange reaction is preferably carried out in an atmosphere of an inert gas such as nitrogen or argon in order to avoid side reactions such as oxidation. In addition to the ligand exchange reaction, the light-shielding conditions may be preferable in the post-treatment process for producing ultrafine particles. After the ligand exchange reaction, to isolate the product, any purification method such as filtration, combined use of precipitation and centrifugation, distillation, sublimation and the like may be used. This is a combination of precipitation and centrifugation, which takes advantage of the fact that the specific gravity is larger than the usual organic compounds. Centrifugation removes the liquid containing the product of the ligand exchange reaction from PA
It is charged into a poor solvent (for example, an organic solvent containing a hydrocarbon such as n-hexane, cyclohexane, heptane, octane, isooctane) of the semiconductor ultrafine particles of the present invention to which G- (1) is bonded, and the suspension containing the generated precipitate is added. The suspension is centrifuged. The obtained precipitate is separated from the supernatant by decantation or the like, and if necessary, solvent washing or re-dissolution and re-precipitation / centrifugation are repeated to improve the degree of purification. For re-dissolution, for example, aromatic hydrocarbons such as toluene, halogenated alkyls such as chloroform and dichloroethane, ethanol, isopropyl alcohol, n-butanol, te.
Lower alcohols having about 4 or less carbon atoms such as rt-butyl alcohol, ketones such as acetone, cyclic ethers such as tetrahydrofuran, esters such as ethyl acetate, and solvents such as water are used. You may mix and use it. The centrifugation speed is usually 10 per minute.
0 to 8000 rpm, preferably 300 to 600 per minute
About 0 rotations, more preferably about 500 to 4000 rotations per minute, the temperature is usually about -10 to 100 ° C, preferably about 0 to 80 ° C, more preferably about 10 to 70 ° C, most preferably 20 to 60 ° C. Perform within the range of about ℃. Also, in this purification step, in order to avoid side reactions such as oxidation,
It may be desirable to perform in an inert gas atmosphere such as nitrogen or argon.

[Thin-Film Molded Article] The semiconductor ultrafine particles of the present invention can be molded by a conventional method and can be applied to various purposes. One example is a thin-film molded article. Such a thin-film molded article is obtained by using the semiconductor ultrafine particles of the present invention obtained by the above-mentioned production method in a suitable solvent (for example, an aromatic solvent such as toluene, a ketone solvent such as acetone, an ether solvent such as tetrahydrofuran, or chloroform). , A halogenated solvent such as methylene chloride or chlorobenzene, etc.) or the like, and then dissolve it in a desired substrate such as a glass substrate,
Conductive substrates such as indium-doped tin oxide (commonly known as ITO), metal or graphite, semiconductor substrates such as silicon, amorphous polyolefins such as polymethylmethacrylate (PMMA), polystyrene and polycycloolefin, aromatic polycarbonates, etc. It can be molded by casting on a resin substrate or the like.

At this time, the polyalkylene glycol residue which is a ligand functions as a continuous matrix which makes it difficult for the semiconductor crystals to aggregate with each other, and provides a stable coating film exhibiting the light absorption and emission characteristics of the semiconductor crystals. That is, one feature of the semiconductor ultrafine particles of the present invention is that they have a polyalkylene glycol residue on the surface thereof, so that they are excellent in transparency and mechanical strength even when an organic binder component such as a resin is not necessarily used in combination. To give the film by itself. During molding by such casting coating, an appropriate organic binder component such as polymethylmethacrylate (PMMA) is previously prepared.
It is also possible to dissolve resins such as or polystyrene or aromatic polycarbonate, waxes and silicone oils and fats in a solvent. In this case, the amount of the organic binder component is usually 0 to 90% by weight based on the total amount of the ultrafine particles, and preferably 5 to 5 in terms of the mechanical properties of the film and optical characteristics such as brightness, absorbance and light transmittance. 80% by weight, more preferably 10-70% by weight, most preferably 15-60% by weight
Is.

Further, in the thin film-shaped molded product of the present invention, as long as its effect is not significantly impaired, any additive such as a heat stabilizer, a light absorber for ultraviolet rays, an antioxidant, an oxygen scavenger, etc. It is also possible to add a moisture absorbent or the like. The thin-film molded body may be molded into a flat surface or a curved surface having an arbitrary curvature. The thick film is not particularly limited, but is preferably about 0.003 to 5000 μm, and preferably 0.004 to 1 in terms of brightness, absorbance or light transmittance.
About 000 μm, more preferably 0.005 to 500 μm
m, most preferably about 0.005 to 100 μm.

A layer having an additional function on one side or both sides of the thin film molded body (for example, a protective layer against mechanical damage, a gas barrier layer, a light blocking layer, a heat insulating layer, an electrode layer, etc.)
Can be provided if necessary. The above-mentioned thin-film molded article of the present invention is a planar light-emitting body used for a display, a lighting device, or the like that makes use of the light emission characteristics of the ultrafine particles, a super-resolution layer that makes use of the absorption characteristics, a filter, or absorption-light emission characteristics. It is industrially useful as an optical material for high-density recording layers and the like. [Optical Material] The semiconductor ultrafine particles of the present invention can be used as various optical materials by forming, for example, a thin-film molded body or a bulk molded body. The use as a particularly important optical material will be described below. 1) Super-Resolution Film The ultrafine particles of the present invention are used as a super-resolution film provided on an optical recording medium such as an optical disk by forming a thin film-shaped molded product.
The term "super-resolution" in the present invention means, for example, in reading or writing data on an optical disc (hereinafter abbreviated as "reading and writing of data"), the resolution, that is, the area of a unit recording area is used for reading and writing data. This means the technical concept of improving the recording density by making the diameter smaller than the original diameter of the light beam, and the light absorption saturation characteristic of semiconductor crystal particles is used.

The above-mentioned light absorption saturation characteristic means that when light of a specific wavelength absorbed by the semiconductor crystal particles (hereinafter referred to as "incident light") is incident, the absorbance of the semiconductor crystal at the specific wavelength is the incident wavelength. It means the property of decreasing with increasing light intensity. Qualitatively, such a light absorption saturation characteristic is such that an increase in the incident light intensity (that is, an increase in the number of photons in the incident light) increases the excitation frequency of electrons to the excitation level involved in absorption,
Therefore, it is understood that the electron existence probability of the excited level also increases, and as a result, the electron transition probability to the excited level decreases. When the intensity of the incident light is sufficiently high, it is assumed that the absorption of light will no longer substantially occur, and such a phenomenon is called "light absorption saturation".

When the semiconductor ultrafine particles of the present invention are applied to a super-resolution film, the absorbance of the thin-film molding of the present invention at a desired incident light wavelength is usually 0.1 or more, preferably 0.3 or more, and further It is preferably 0.5 or more. However, the value of the absorbance is usually 0.
It is measured by making incident light with an intensity of about 3 mW or less, preferably 0.1 mW or less, incident from the normal direction of the surface of the molded body.

The thickness of the super-resolution film is not limited as long as effective photo-saturation absorption can be detected.
The thickness is 10,000 nm, preferably 100 to 5000 nm, more preferably 150 to 3000 nm, and the distribution of the film thickness is desirably as small as possible. The surface of the film is preferably as smooth as possible in order to suppress light scattering.

The semiconductor crystal particles that are preferably used when the thin film compact of the present invention is applied to a super-resolution film are CdS or ZnSe as described above, and a semiconductor having a larger band gap such as ZnS. A core-shell type particle provided with a crystalline shell is preferable because the exciton absorption behavior based on the quantum effect may be stabilized. The content of such semiconductor crystal particles in the super-resolution film is usually 1
0 to 60% by volume, preferably 20 to 55% by volume, more preferably 25, from the viewpoint of detectability of light absorption saturation and mechanical strength of the film.
˜50% by volume. (2) Filter When the ultrafine particles of the present invention are formed into a thin film-shaped molded product, they are used as a filter by utilizing their transparency and the light absorption characteristics of the semiconductor crystal particles contained therein. Since the semiconductor ultrafine particles can change the absorption wavelength according to the particle size thereof, it is possible to create a filter in which the absorption wavelength is precisely controlled. Such a filter is used as a color filter for a display because it can extract only light in a specific wavelength range. Examples of semiconductor crystal particles suitable for this purpose include cadmium selenide (CdSe) and cadmium sulfide (CdS). Further, when absorbing ultraviolet rays, when is absorbed in the ultraviolet region, it is used as an ultraviolet absorbing film. Such an ultraviolet absorbing film is formed by closely contacting with the surface of a transparent member that needs to suppress or block the transmission of ultraviolet rays such as sunlight and the like, for example, a window glass of an automobile, an aircraft, a building, or a lens of sunglasses. Used in form, for example. Suitable semiconductor crystal particles for such purpose include, for example, the above-mentioned titanium oxides, zirconium oxide (ZrO ₂ ), zinc oxide (Zn oxide) whose absorption spectrum has a long-wavelength side absorption edge wavelength of 400 nm or less.
O) and zinc sulfide (ZnS) are exemplified.

From the viewpoint of light absorption ability, it is desirable that the content of semiconductor crystal particles in the thin film shaped article is as large as possible.
Usually 10 to 60% by volume, preferably 20 to 55% by volume, more preferably 3 from the viewpoint of ultraviolet absorption capacity and mechanical strength of the film.
It is about 0 to 50% by volume. Incidentally, when the content of the semiconductor crystal particles in the thin-film molded body becomes large, a secondary characteristic that the hardness as a filter becomes large appears. Become.

The film thickness of such a filter is not limited as long as it exhibits an effective ultraviolet absorbing ability, but is usually 0.05 to 2000 μm, preferably 0.1 to 1000.
μm, and more preferably about 0.5 to 500 μm.
Further, the distribution of the film thickness may be freely designed according to the intended function of the transparent member. The surface of the film is preferably as smooth as possible in order to suppress a decrease in light transmittance due to light scattering, but suitable irregularities may be provided depending on the purpose. (3) Reflection control film By using the semiconductor ultrafine particles of the present invention as a thin film shaped body,
It is used as a reflection control film utilizing its transparency and the high refractive index of the semiconductor crystal particles contained therein. Such a reflection control film is provided on the surface of a transparent member such as a display panel, a lens, a prism, or a window glass, and exerts an effect of suppressing light reflection on the surface of the transparent member. Suitable semiconductor crystal particles for this purpose include, for example, the above-mentioned titanium oxides, zirconium oxide (ZrO ₂ ), zinc oxide (ZnO ₂ ).
O) and zinc sulfide (ZnS) are exemplified.

From the viewpoint of increasing the refractive index of the thin-film molded body, it is desirable that the content of the semiconductor crystal particles in the thin-film molded body be as large as possible, but usually 10 to 60% by volume is required to increase the refractive index. From the mechanical strength of the film, it is preferably 15 to 50% by volume, more preferably about 20 to 45% by volume. In practical terms,
The refractive index of the thin film molded article at 23 ° C. at the sodium D-line wavelength is usually 1.6 or more, and this value is preferably 1.
It is 7 or more, more preferably 1.8 or more, and most preferably 1.9 or more. Incidentally, when the content of the semiconductor crystal particles in the thin film-shaped molded body becomes large, a secondary characteristic that the hardness as the reflection control film becomes large appears, so that when the surface hardness of the transparent member is required, Will be suitable.

The surface of the reflection control film provided by the present invention may be provided with a film made of a material having a relatively small refractive index such as PMMA or silica. By providing such a low refractive index film, an excellent antireflection function may be exhibited, which is preferable. In particular, the formation of the silica film on the surface is also useful as a function as a protective function layer against mechanical external force (for example, friction and abrasion) due to its excellent surface hardness.

The thickness of the reflection control film is not limited as long as it exerts an effective reflection control ability, but is usually 0.05 to 500 μm, preferably 0.1 to 100 μm.
m, and more preferably about 0.2 to 10 μm. Further, the distribution of the film thickness may be freely designed according to the intended function of the transparent member. It is usually desirable that the surface of the film is as smooth as possible in order to suppress a decrease in light transmittance due to light scattering, but appropriate irregularities may be provided depending on the purpose. (4) Optical Waveguide The ultrafine particles of the present invention are used as an optical waveguide utilizing its transparency and the high refractive index of the semiconductor crystal particles contained therein. Such an optical waveguide is used as an optical connector or an optical amplifier in optical communication. The refractive index of the optical waveguide provided by the present invention at 23 ° C. at the sodium D-line wavelength is usually 1.
Since it is 6 or more, PMMA (refractive index 1.4
A general-purpose resin material such as 9) can be easily applied by forming it into a thin film by a solution coating method or molding it into a rod shape. The refractive index of the optical waveguide is preferably 1.7.
Or more, and more preferably 1.75 or more.

Suitable semiconductor crystal particles for this purpose include, for example, the above-mentioned titanium oxides and zirconium oxide (Z
Examples thereof include rO ₂ ), zinc oxide (ZnO), zinc sulfide (ZnS), and the like. From the viewpoint of increasing the refractive index of the molded body, it is desirable that the content of the semiconductor crystal particles in the molded body is as large as possible, but it is usually 10 to 60% by volume, preferably from the viewpoint of high refractive index and mechanical strength of the film. Is 15 to 55% by volume, more preferably about 20 to 50% by volume. (5) Light-Emitting Layer of Electroluminescence Element The ultrafine particles of the present invention are used as a light-emitting layer of an electroluminescence element (EL element) utilizing its transparency and the emission spectrum specific to the semiconductor crystal particles contained therein. Such an EL element has many excellent features such as high-luminance emission, high-speed response, wide viewing angle, thin and lightweight, and high resolution, and is applied to, for example, a flat panel display. Therefore, it is desirable that the light emitting layer be transparent so as not to cause a decrease in light emitting efficiency due to scattering or the like, and contain a semiconductor crystal at a high density. Therefore, as the semiconductor crystal particles contained in the light emitting layer used for such an application, for example, the above-mentioned cadmium selenide (CdSe), zinc selenide (ZnSe), zinc oxide which gives an emission spectrum in a wavelength range from ultraviolet to near infrared are used. Examples thereof include (ZnO) and cadmium sulfide (CdS).

When the semiconductor ultrafine particles of the present invention are used as a thin film as a light emitting layer of an EL device, the film thickness thereof is not limited as long as it exhibits an effective light emitting ability, but is usually 5 to 5.
The thickness is 10000 nm, preferably 20 to 2000 nm, and more preferably 50 to 500 nm. The content of semiconductor crystals in the light emitting layer is usually 10 to 60% by volume, preferably 20 to 55% by volume, and more preferably 25 to 5% by volume.
It is 0% by volume.

[0076]

EXAMPLES Hereinafter, specific embodiments of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded.
As the raw material reagent, a commercially available reagent was used without purification unless otherwise specified. However, a commercially available solvent was used as a purified solvent by the following purification operation. Purified toluene ...
The extract was washed with concentrated sulfuric acid, water, saturated aqueous sodium hydrogen carbonate, and water in that order, dried over anhydrous magnesium sulfate, filtered through filter paper, and added with phosphorus pentoxide (P ₂ O ₅ ) and distilled at atmospheric pressure.

[Measuring device and conditions, etc.] (1) Nuclear magnetic resonance (NMR) spectrum: JNM-EX270 type FT-NMR (1H: 270M, manufactured by JEOL Ltd.)
Hz, 13C: 67.8 MHz). Unless otherwise specified, deuterated chloroform was used as a solvent, and tetramethylsilane was measured at 23 ° C. with 0 ppm as a control. (2) Infrared absorption (IR) spectrum: FT / IR-8000 type FT-IR manufactured by JASCO Corporation. It was measured at 23 ° C. (3) Photoexcited luminescence (PL) spectrum: under the conditions of scan speed 60 nm / min, excitation side slit 5 nm, fluorescence side slit 5 nm, Photomalt voltage 400 V in F-2500 type spectrofluorimeter manufactured by Hitachi, Ltd. The measurement was performed at room temperature using a quartz cell having an optical path length of 1 cm. (4) Absorption spectrum: Hewlett-Packard H
It was measured at room temperature with a P8453 type ultraviolet / visible absorptiometer using a quartz cell having an optical path length of 1 cm. (5) Film thickness measurement: using a cross-section and surface roughness fine shape measuring device P-15 manufactured by KLA-Tencor Co., Ltd.
The scanning length was 10 to 20 mm, the scanning speed was 0.2 mm / sec, and the needle pressure was 0.2 to 2.0 mg.

[Synthesis Example: Synthesis of Semiconductor Nanocrystal] Synthesis Example 1: Synthesis of CdS Nanocrystal Made of colorless and transparent Pyrex (registered trademark) glass equipped with an air-cooled Liebig reflux tube and a thermocouple for controlling reaction temperature. Trioctylphosphine oxide (hereinafter abbreviated as TOPO; Storm Chemical) in a 4-necked flask.
(Purity: 90%; 13 g) was charged, and the inside was replaced with Ar by flowing Ar for 30 minutes, and the mixture was heated to 300 ° C. while stirring with a magnetic stirrer. Separately, in a glove box with a dry nitrogen atmosphere, dimethyl cadmium (S
trem Chemical Company; 10 wt% n-hexane solution; 1.12 g) and bis (trimethylsilyl) sulfide (Fluka; 0.066 mL) in tributylphosphine (hereinafter abbreviated as TBP; Strem Chem)
The raw material solution A dissolved in ical (5.1 g) was prepared in a glass bottle which was sealed with a rubber stopper (septum supplied from Aldrich), wrapped with aluminum foil without gaps, and protected from light. This raw material solution A (6 mL) was added to the above T
It was injected all at once with a syringe into the flask containing OPO, and this time was taken as the reaction start time. The reaction was carried out by shielding the flask and the reflux tube with aluminum foil and shielding them from light. Reaction start 2
After 0 minutes, the heat source was removed and when cooled to about 50 ° C., anhydrous methanol (Aldrich; Anhydros;
1.4 mL) was injected and the mixture was further cooled to room temperature. This reaction solution was added dropwise to anhydrous methanol (45 mL) under a nitrogen atmosphere and stirred for 5 minutes to give a yellow insoluble matter. This insoluble material was centrifuged (3500 rpm), and the supernatant was removed by decantation to separate the solid material.
This solid powder was dissolved in purified toluene (2 mL), poured into anhydrous methanol (30 mL), stirred at room temperature for 5 minutes, and the solid precipitate was separated by the same centrifugation and decantation as described above. The precipitate was vacuum dried and then vacuum dried overnight at room temperature to obtain a yellow solid powder (hereinafter abbreviated as CdS-TOPO; 85.2 mg).

The yellow solid powder thus obtained was dispersed in toluene and the absorption spectrum was measured.
I had it at 04 nm. Further, when the emission spectrum was measured (excitation light 366 nm), the peak wavelength was 435.5.
Two emission bands were given at nm and 523.5 nm. Synthesis Example 2: Synthesis of CdSe nanocrystals TOPO (6 g) was placed in a colorless and transparent Pyrex (registered trademark) 4-necked flask equipped with an air-cooled Liebig reflux tube and a thermocouple for controlling a reaction temperature, and 30 minutes. The inside was replaced with Ar by Ar flow, and the mixture was heated to 350 ° C. with stirring with a magnetic stirrer. Separately
Selenium (single black powder; Aldrich; 0.1 g) in TBP in a dry nitrogen atmosphere glove box
A raw material solution B prepared by further mixing and dissolving dimethylcadmium (2.18 g) in a liquid dissolved in (5.38 g) was prepared in a glass bottle which was sealed with a rubber stopper and wrapped with aluminum foil without any gaps to shield light. This raw material solution B (3 mL) was injected all at once into the flask containing TOPO with a syringe, and this time was taken as the reaction start time. Immediately after the injection, the temperature was set to 300 ° C, and after 10 minutes from the start of the reaction, the heat source was removed and when cooled to about 60 ° C, anhydrous methanol (15 mL) was added.
Was injected to produce an insoluble material. This insoluble material was centrifuged (3000 rpm), and the supernatant was removed by decantation to separate the solid material. This solid powder was dissolved in purified toluene (3 mL), and anhydrous methanol (3 mL) was added.
(0 mL) and stirred at room temperature for 5 minutes, and the solid precipitate was separated by the same centrifugation and decantation as described above. This solid was dried at room temperature under a stream of dry nitrogen and then vacuum dried overnight at room temperature to give a red solid powder (hereinafter CdSe-TOPO).
, And 99.6 mg) was obtained.

The red solid powder thus obtained was dissolved in toluene and the absorption spectrum was measured.
I had it at 36 nm. The emission spectrum was measured (excitation light: 366 nm) to give a green emission band (peak wavelength 549.5 nm). Synthesis Example 3: Synthesis of ZnO nanocrystals. Phys. Chem. B, 102
Vol., 5566-5572 (1998). Zinc acetate dihydrate (Kanto Chemical Co., Ltd.) in a colorless and transparent Pyrex (registered trademark) glass 4-necked flask;
0.2219g) and ethanol (Junsei Kagaku Co., Ltd .; 10
mL) was added and heated at 90 ° C. for 5 minutes. Then, the zinc acetate was completely dissolved, and the solution became colorless and transparent. When this solution was cooled to 0 ° C. with an ice bath, the temperature became lower and the solution became cloudy. Lithium hydroxide monohydrate (Kishida chemistry; 0.0586 g) was dissolved in ethanol (10 mL) by applying ultrasonic waves thereto, and the solution stored at 0 ° C. was slowly added dropwise. The solution became colorless and transparent when a few mL was dropped. After dropping all, the mixture was stirred at room temperature for 1 hour. When n-hexane (40 mL) was added thereto, it became cloudy, and white precipitation was obtained by centrifugation (3000 rpm). This white precipitate was suspended in ethanol (6 mL) (not dissolved), n-hexane (12 mL) was added,
A white precipitate was collected by centrifugation (3000 rpm) and dried by a nitrogen flow to obtain a white solid (67.7 mg). However, this white solid was hardly dissolved in an organic solvent or the like.

Example 1: 10-phosphonodecyl MTEG
Synthetic oily sodium hydride of ether (Wako Pure Chemical Industries, Ltd .: 741.
(6 mg) was placed in a flask, and the inside of the container was replaced with argon, and then triethylene glycol monomethyl ether (hereinafter abbreviated as MTEG, Tokyo Kasei Co., Ltd .: 1.27 g) and distilled dimethylformamide (at a temperature of 0 ° C.) under an argon stream. 10 mL) was added and mixed, and the mixture was stirred at room temperature for 30 minutes.
After transferring the flask onto a cold water bath and adding 1,10-dibromodecane (Tokyo Kasei: 9 mL) with stirring,
The mixture was stirred at room temperature for 3.5 hours and left at room temperature overnight. Methanol (Junsei Kagaku Co., Ltd .: 3 mL) was added to the reaction mixture, the mixture was stirred at room temperature for 30 minutes, and concentrated under reduced pressure. Methylene chloride (Junsei Kagaku Co., Ltd .: 100 m) was added to the reaction mixture after concentration.
L) and the organic layer was washed with water, dried over magnesium sulfate, filtered, concentrated, and dried under vacuum at room temperature to give a crude product. The crude product was purified by silica gel chromatography using n-hexane-ethyl acetate to obtain 10-bromodecyl MTEG ether.

10-bromodecyl MTEG ether (3
(82.4 mg) was placed in a flask, and the inside of the container was replaced with argon, and then tris (trimethylsilyl) phosphite (Tokyo Kasei Co., Ltd .: 1.05 g) under an argon stream.
After adding and mixing and stirring at 120 ° C. for 13.5 hours,
The mixture was cooled to 85 ° C. with stirring, excess tris (trimethylsilyl) phosphite was removed under reduced pressure, and the mixture was cooled to room temperature when no reduction in the reaction mixture was observed. After returning the pressure in the container to normal pressure with argon, tetrahydrofuran / water = 5/1 (volume ratio, 3.2 mL) was added, and the mixture was stirred at room temperature for 3 hours and further stirred under reduced pressure for 1 hour.
Chloroform was added to the remaining reaction mixture for extraction, the extract was passed through a silica gel column (silica gel amount 0.09 g), and the column was washed with chloroform. The extract passed through the column and the washing solution were combined and concentrated under reduced pressure. Ethanol was added to the residue to dissolve it, and the mixture was concentrated under reduced pressure again. Ethyl acetate was added to the residue to dissolve it, and the residue was concentrated again under reduced pressure and dried under vacuum at room temperature (351.6 mg).

The product is 27 in the IR spectrum.
50cm ^-1, 2363cm ^-1, 1199cm ^-1 and 10
MTE to 18cm ^-1 phosphonic acid structure, a 1107Cm ^-1
Ether structure derived from G, and 2928 cm ^-1 and 2856
Absorption bands assigned to the alkylphosphonic acid and the hydrocarbon structure derived from MTEG were given in cm ⁻¹ . Further 1H
In -NMR, a reasonable signal and an integrated value that match the expected structure were given as described below, so that 10-phosphonodecyl MTEG ether (hereinafter MTEG-C10PA
Abbreviated) was isolated. 1H-NMR spectrum: 1.16-1.84 (multiplet, 18 protons, phosphonic acid aliphatic chain), 3.
35 (singlet, 3 protons, methyl group), 3.4
2 (triplet, 2 protons, J = 6.6 Hz, phosphonic acid side methylene group adjacent to ether bond), 3.5
0-3.70 (multiplet, 12 protons), 8.
86 (Broad singlet, 2 protons, hydroxyl group derived from phosphonic acid)

Example 2: Synthesis of CdS ultrafine particles coordinated with MTEG-C10PA CdS-TOPO obtained by the procedure described in Synthesis Example 1 was coordinated so that MTEG-C10PA synthesized in Example 1 was easily coordinated. Further, it was purified three times with toluene and ethanol.
After that, CdS-TOPO (0.0194g) and MTE
Ethanol (5 mL) in G-C10PA (0.01 g)
Was added and the mixture was heated to reflux for about 4 hours with stirring under Ar atmosphere. By this heating under reflux, the semiconductor nanocrystals of Synthesis Example 1 were dissolved to give a yellow ethanol solution having no turbidity. The reaction solution was concentrated under reduced pressure, and n-hexane (20 m
L) was added and the mixture was irradiated with ultrasonic waves for about 20 seconds to disperse it, and then insoluble matter was separated by centrifugation (3000 rpm, 6 minutes) and decantation. The insoluble matter thus separated was redissolved in toluene (0.5 mL), n-hexane (20 mL) was added to form a precipitate, which was separated by centrifugation and decantation in the same manner as above. The operations of redissolving, precipitating and separating were repeated once again for purification. The precipitate thus obtained was dried under vacuum at room temperature to remove the solvent to obtain a yellow solid (16.9 mg).

The yellow solid thus obtained was dissolved in toluene, chloroform and tetrahydrofuran to give CdS-TOP.
It was very well dissolved in acetone, which has low solubility of O, N, N-dimethylformamide, ethyl acetate, and ethanol and methanol in which CdS-TOPO is hardly dissolved, to give a yellow solution having no turbidity. This is MTEG-C10
It is considered that PA was coordinated on the surface of the CdS crystal. The peak positions of the absorption band and the emission band are Cd before ligand exchange.
It was almost the same as S-TOPO. However, when the emission intensity is compared with that of CdS-TOPO having the same absorbance using the same toluene as a solvent, the peak emission intensity at the short wavelength is 7. in the two emission bands of the CdS ultrafine particles coordinated with MTEG-C10PA. The peak emission intensity at 9 times the long wavelength was 4.4 times (FIG. 1). It is considered that this increase in emission intensity is due to MTEG-C10PA filling the level of the non-emission process existing on the surface of the CdS nanocrystal.

Further, this yellow solid (1.5 mg) was mixed with a mixture of toluene and chloroform (volume ratio 1: 1, 26 μm).
L) and spin coated on a quartz substrate (750 rp)
m), a yellow coating film with a turbidity (film thickness 180n
m), and this coating film gave a light emission band similar to that of the solution.

Example 3: Synthesis of CdSe ultrafine particles coordinated with MTEG-C10PA CdSe-TOPO obtained by the procedure described in Synthesis Example 2.
(0.032 g) and MTEG-C1 synthesized in Example 1
Ethanol (7.5 mL) in 0PA (0.0158 g)
Was added and the mixture was heated under reflux for about 5 hours while stirring under an Ar atmosphere. By this heating under reflux, the semiconductor nanocrystals of Synthesis Example 2 were dissolved to give a red ethanol solution without turbidity. The reaction solution was concentrated under reduced pressure, and n-hexane (30 m
L) was added and the mixture was irradiated with ultrasonic waves for about 20 seconds to disperse it, and then insoluble matter was separated by centrifugation (3000 rpm, 6 minutes) and decantation. The insoluble matter thus separated was redissolved in toluene (0.7 mL) and poured into n-hexane (35 mL) to form a precipitate, which was separated by centrifugation and decantation in the same manner as above.
The operations of redissolving, precipitating and separating were repeated once again for purification. The precipitate thus obtained was vacuum dried at room temperature to remove the solvent and obtain a red solid (30.8 mg).

The red solid thus obtained was dissolved in toluene, chloroform and tetrahydrofuran, and CdSe-TO
It was very well dissolved in acetone, which has low solubility of PO, N, N-dimethylformamide, ethyl acetate, and ethanol and methanol in which CdSe-TOPO was hardly dissolved, to give a red solution having no turbidity. This is MTEG-C
It is considered that 10PA was coordinated to the surface of the CdSe crystal. The peak positions of the absorption band and the emission band were the same as those of CdSe-TOPO before ligand exchange. Further, when compared with CdSe-TOPO having the same absorbance using the same toluene as a solvent, CdS coordinated with MTEG-C10PA was used.
e The peak emission intensity in the emission band of ultrafine particles increased 4.9 times (excitation light 366 nm) (FIG. 2). Further, when this red solid (1.5 mg) was dissolved in a mixed solution of toluene and chloroform (volume ratio 1: 1, 26 μL) and spin-coated (750 rpm) on a quartz substrate, a red-colored coating film (film thickness) without turbidity was obtained. 130 nm), and this coating film gave an emission band similar to that of the solution.

Example 4: Synthesis of ZnO ultrafine particles coordinated with MTEG-C10PA ZnO (0.0202) obtained by the procedure described in Synthesis Example 3
g) and MTEG-C10PA synthesized in Example 1 (0.
Ethanol (5 mL) was added to (0209 g) and the mixture was heated under reflux for about 7 hours while stirring in an Ar atmosphere. Since the solution was cloudy even after heating under reflux, the insoluble matter was removed by centrifugation. This insoluble matter is considered to be bulk ZnO crystals generated when the ZnO nanocrystallites were synthesized in Synthesis Example 3. To the residue obtained by concentrating the obtained colorless transparent supernatant under reduced pressure, n-hexane (25 mL) was added and sonicated for about 20 seconds to disperse the mixture, followed by centrifugation (3000 rp).
The insoluble matter was separated by decantation. The insoluble matter thus separated was redissolved in toluene (1 mL), and n-hexane (25 mL) was added to produce a precipitate, which was then purified. The precipitate thus obtained was vacuum dried at room temperature to remove the solvent and obtain a white solid (24 m
g).

The white solid thus obtained was dissolved in toluene, chloroform, ethanol, methanol, ethyl acetate, acetone, N, N-dimethylformamide and tetrahydrofuran to give a colorless transparent solution. It is considered that this is because MTEG-C10PA was coordinated on the surface of the ZnO nanocrystal. The peak wavelength of the absorption spectrum when dissolved in toluene was 333 nm, and the peak wavelength of the emission spectrum was 522 nm. In addition, this white solid (2
Spin coating (500 rpm) of a chloroform solution (20 μL) of (mg) on a quartz substrate gave a colorless coating film (film thickness 500 nm) without turbidity, and this coating film gave the same emission band as that of the solution. It was

Synthesis Example 4: Synthesis of InP nanocrystals having ZnS shell I. Micic et al .; Phys. Chem. B,
It was carried out according to the method described in Volume 102, page 9791.
This will be described below. A transparent and colorless Pyrex (registered trademark) (R) glass three-necked flask equipped with an air-cooled Liebig reflux tube and a thermocouple for controlling the reaction temperature was charged with trioctylphosphine (Aldrich; 6 g, hereinafter abbreviated as TOP). Then, the mixture was heated to 300 ° C. in a dry argon gas atmosphere while stirring with a magnetic stirrer. Separately
TOP (10 mL) of indium chloride (Kishida Chemical Co., Ltd .; 3 g) in a glove box in a dry argon atmosphere.
Solution (1 at 260 ° C under a dry argon atmosphere)
Prepared by heating for 0 hours, 1 mL) and tristrimethylsilylphosphine (manufactured by ACROSS; 0.2832)
A raw material solution prepared by mixing a liquid obtained by dissolving g) in TOP (1 mL) was prepared in a glass bottle sealed with a rubber stopper. All of this raw material solution was injected all at once into the flask containing TOP with a syringe, and this time was taken as the reaction start time. Immediately after the injection, the set temperature was set to 260 ° C. and heating was continued for 9 hours. After that, let it cool to room temperature, leave it overnight, and then 260 ° C again.
After heating for 9 hours, the mixture was allowed to cool, left overnight, and further heated for 6 hours. Then, when the heat source was removed and the temperature was cooled to about 60 ° C., anhydrous n-butanol (20 mL) was added, and the mixture was cooled to room temperature. This reaction solution was mixed with anhydrous methanol (100 m
L) was added dropwise and stirred for 5 minutes to generate a black insoluble matter. This insoluble matter is centrifuged (3000 rpm)
Then, the supernatant was removed by decantation and separated to obtain a solid powder. This solid powder was added to toluene (25 m
L), filtered through a membrane filter with a pore size of 0.2 μm, concentrated the solution to 15 mL with N ₂ flow, and then dried with anhydrous methanol / anhydrous n-butanol (50% each).
(mL / 25 mL) was added dropwise to the mixed solvent, and the insoluble matter was centrifuged as described above. A black solid (hereinafter abbreviated as InP-TOP; 158.8 m) was obtained by vacuum drying this insoluble material overnight.
g) was obtained. The black solid thus obtained was dissolved in chloroform and the absorption spectrum was measured. As a result, the black solid showed the same absorption spectrum as in the above paper. Further, the emission spectrum was measured (excitation light: 450 nm), but almost no light was emitted.

TOPO (3 g), TOP (5 mL) in a brown glass three-necked flask equipped with an air-cooled Liebig reflux tube and a thermocouple for controlling the reaction temperature.
The nP nanocrystals (0.030 g) were stirred under reduced pressure of 100 ° C. for about 1 hour, then the temperature was set to 260 ° C. and the pressure was restored to atmospheric pressure with Ar. Separately, in a glove box in a dry nitrogen atmosphere, a 1N concentration solution of diethylzinc in n-hexane (0.
8 mL) and bis (trimethylsilyl) sulfide (0.
1687 mL) was dissolved in TOP (5 mL) to prepare a raw material solution in a glass bottle sealed with a rubber stopper. All of the raw material solutions were mixed with a syringe to obtain In at 260 ° C.
Drop into a clear solution containing P nanocrystals over 45 minutes and
After the temperature was lowered to 00 ° C, stirring was continued for about 4 hours. After standing at room temperature overnight, toluene (20 mL) was added, the reaction solution was transferred to a colorless transparent glass bottle, the insoluble matter was precipitated by centrifugation, and left as it was for 5 days. This reaction liquid was dropped into anhydrous methanol (80 mL) and stirred for 5 minutes to generate a black insoluble matter. The black insoluble matter was separated by centrifugation and decantation in the same manner as described above, dissolved in toluene (10 mL), filtered through a membrane filter having a pore size of 0.2 μm, and the solution was concentrated to 7 mL by N ₂ flow, followed by anhydrous methanol / Anhydrous n-butanol (40 mL / 20 mL each) was added dropwise to the mixed solvent. The insoluble matter was separated by centrifugation and decantation in the same manner as above, and vacuum-dried overnight to obtain a black solid (hereinafter abbreviated as InP / ZnS-TOPO; 63.1 mg). The black solid thus obtained was dissolved in chloroform and the absorption spectrum was measured. As a result, the absorption spectrum was similar to that of InP-TOP. Further, the emission spectrum was measured (excitation light 450 nm) to give a red emission band (peak wavelength 625 nm). This luminescence was converted to an InP nanocrystal having a ZnS shell at a similar solution concentration because the InP nanocrystal before having a ZnS shell showed almost no luminescence. It was considered that the contribution of the above was suppressed.

Example 5: Synthesis of InP ultrafine particles having a ZnS shell coordinated with MTEG-C10PA InP / ZnS-TO obtained by the procedure described in Synthesis Example 4.
PO (0.020 g) and MTEG-synthesized in Example 1
Ethanol (5 mL) was added to C10PA (0.020 g), and the mixture was heated under reflux for about 6 hours while stirring in an Ar atmosphere. By this heating under reflux, the semiconductor nanocrystal of Synthesis Example 12 was dissolved to give a black ethanol solution having no turbidity. The reaction solution was concentrated under reduced pressure, the obtained residue was dissolved in toluene (3 mL), this solution was added to n-hexane (25 mL), and then the insoluble matter was separated by centrifugation and decantation. The insoluble matter thus separated was redissolved in toluene (3 mL) and poured into n-hexane (25 mL) to form a precipitate, which was separated by centrifugation and decantation in the same manner as above. The operations of redissolving, precipitating and separating were repeated once again for purification. The precipitate thus obtained was dissolved in toluene (6 mL), filtered through a membrane filter having a pore size of 0.2 μm, and the solution was washed with N ₂ flow to 3 m of the solution.
After concentrating to L, it was added dropwise to n-hexane (25 mL). The insoluble matter was separated by centrifugation and decantation in the same manner as above, and vacuum dried overnight to obtain a black solid (hereinafter abbreviated as InP / ZnS-MTEG-C10PA;
21.9 mg).

The black solid thus obtained was dissolved in toluene, chloroform and ethanol to give a clear brown solution. This is because MTEG-C10PA is InP / ZnS.
It is considered that this is because it is coordinated on the crystal surface. The peak positions of the absorption band and the emission band are InP / ZnS- before ligand exchange.
It was almost the same as TOPO. Also, using the same chloroform as a solvent, InP / ZnS-TO with the same absorbance
When compared with PO, the peak emission intensity of the emission band of InP / ZnS ultrafine particles coordinated with MTEG-C10PA increased 4.1 times (excitation light 450 nm) (FIG. 3). Further, when this black solid (1 mg) was dissolved in a mixed solution of toluene and chloroform (volume ratio 1: 1, 20 μL) and spin-coated (500 rpm) on a quartz substrate, a brown coating film without turbidity (film thickness 400 nm) The coating film gave a red emission band similar to that of the solution.

Synthesis Example 5: Synthesis of 2,5,8-trioxadecyl-10-phosphonic acid (2- [2- (2-methoxyethoxy) ethoxy] ethylphosphonic acid) Triethylene glycol monomethyl ether (hereinafter MT)
Abbreviated as EG, Tokyo Kasei Co., Ltd .: 2.952 g) and triphenylphosphine (Kishida Chemical Co., Ltd .: 7.581).
g) was placed in a flask, and the inside of the container was replaced with argon, and then dry tetrahydrofuran (hereinafter referred to as T
HF (abbreviation, 50 mL) was added to completely dissolve the contents. The flask was transferred to an ice bath, carbon tetrabromide (Tokyo Kasei Co., Ltd .: 4.951 g) was added little by little over 15 minutes while stirring under an argon stream, and then the mixture was stirred at room temperature for 3 hours. The reaction mixture was concentrated under reduced pressure, and the obtained concentrated liquid was filtered under reduced pressure. The solid remaining on the filter paper was washed twice with n-hexane (Junsei Kagaku Co., Ltd .: 50 mL), and the filtrate and washings were combined and concentrated under reduced pressure to obtain a crude product. The crude product was purified by silica gel chromatography using n-hexane-ethyl acetate to obtain 2,5,8-trioxa-10-bromodecane.

2,5,8-Trioxa-10-bromodecane (1.602 g) was placed in a flask, and the inside of the container was replaced with argon, and then tris (trimethylsilyl) phosphite (Tokyo Kasei Co., Ltd.) was supplied under an argon stream. : 7.2
4 g) was added and mixed, and the mixture was stirred at 120 ° C. for 18 hours, then cooled to 85 ° C. with stirring, and excess tris (trimethylsilyl) phosphite was removed under reduced pressure, and a decrease in the reaction mixture amount was observed. When it disappeared, it was cooled to room temperature. After returning the inside of the container to atmospheric pressure with argon,
Water = 100/1 (volume ratio, 20.2 mL) was added, and the mixture was stirred at room temperature for 3 hours. The reaction mixture was concentrated under reduced pressure, ethanol was added to dissolve it, and the mixture was concentrated under reduced pressure again. Chloroform was added to the residue and dissolved, and the resulting solution was passed through a silica gel column (silica gel amount 0.40 g), and the column was washed with chloroform. The solution passed through the column and the washing solution were combined, concentrated under reduced pressure, and vacuum dried at room temperature (1.578).
g). This product has an IR spectrum of 2750c
m ^-1 , 2364 cm ^-1 , 1196 cm ^-1 and 1016c
m phosphonic acid structure to ^-1, ether structure derived MTEG to 1105Cm ^-1, and 2924 cm ^-1 and 2883Cm ^-1
The absorption bands assigned to the hydrocarbon structures derived from MTEG are given in Table 1. Further, in 1 H-NMR, a reasonable signal and an integrated value that match the expected structure were given as described later, and therefore ethanol was added to dissolve the 2,5,8-trioxadecyl-10-phosphonic acid (hereinafter MTEG-C
(Abbreviated as 0PA) was isolated.

¹ H-NMR spectrum: 2.14 (doublet triplet, 2 protons, J = 18.1 Hz,
7.0 Hz, phosphonic acid side methylene group adjacent to ether bond), 3.39 (singlet, 3 protons, methyl group), 3.55-3.65 (multiplet, 8 protons), 3.78 (doublet triplet) 2 protons, J = 14.3 Hz, 7.0 Hz, methylene group on ether bond side adjacent to ether bond), 8.18 (broad singlet, 2 protons, hydroxyl group derived from phosphonic acid)

Example 6: Synthesis of InP ultrafine particles having a ZnS shell coordinated with MTEG-COPA InP / ZnS-TO obtained by the procedure described in Synthesis Example 4.
MTEG synthesized in PO (0.0103 g) and Synthesis Example 5
-C0PA (0.0126 g) with ethanol (3.5 m
L) was added and the mixture was heated under reflux for about 2.5 hours while stirring under an Ar atmosphere. By this heating under reflux, the semiconductor nanocrystal of Synthesis Example 12 was dissolved to give a black ethanol solution having no turbidity. The residue obtained by concentrating the reaction solution under reduced pressure was washed with toluene (3
mL), and this solution was added to n-hexane (25 mL).
Insoluble matter was separated by centrifugation and decantation. The insoluble matter separated in this way was washed with toluene (2
(mL) and re-dissolved in n-hexane (25 mL) to form a precipitate, which was separated by centrifugation and decantation as described above. The precipitate thus obtained was dissolved in toluene (4 mL), filtered through a membrane filter having a pore size of 0.2 μm, and the solution was washed with N ₂ flow to give
After concentrating to L, it was added dropwise to n-hexane (25 mL). The insoluble matter was separated by centrifugation and decantation in the same manner as described above, and vacuum-dried to obtain a black solid (hereinafter abbreviated as InP / ZnS-MTEG-COPA; 6.0).
mg).

The black solid thus obtained was dissolved in toluene, chloroform and ethanol to give a clear brown solution. It is considered that this is because MTEG-COPA coordinated to the InP / ZnS crystal surface. The peak positions of the absorption band and the emission band are InP / ZnS-T before ligand exchange.
It was almost the same as OPO. Also, using the same chloroform as a solvent, InP / ZnS-TOP having the same absorbance.
In when coordinated with MTEG-COPA when compared with O
The peak emission intensity of the emission band of P / ZnS ultrafine particles is 4.3.
Doubled (excitation light 450 nm) (FIG. 3). Further, when this black solid (1 mg) was dissolved in a mixed liquid of toluene and chloroform (volume ratio 1: 1, 20 μL) and spin-coated (500 rpm) on a quartz substrate, a brown coating film without turbidity (film thickness 250 nm) The coating film gave a red emission band similar to that of the solution.

[0100]

Industrial Applicability The semiconductor ultrafine particles having the polyalkylene glycol residue of the present invention bonded to the surface thereof have good solubility in a solvent, dispersibility in a polymer, excellent coatability, and the semiconductor crystal. It also has controlled absorption and emission characteristics due to the quantum effect. In addition, the application of the solution gives a homogeneous coating with no turbidity, which retains the above-mentioned absorption and emission properties.

[Brief description of drawings]

FIG. 1 is an emission spectrum diagram of CdS ultrafine particles obtained in Synthesis Example 1 and Example 2 in a toluene solution.

FIG. 2 is an emission spectrum diagram of CdSe ultrafine particles obtained in Synthesis Example 2 and Example 3 in a toluene solution.

3 shows I obtained in Synthesis Example 4, Example 5 and Example 6. FIG.
It is an emission spectrum figure in a chloroform solution of nP / ZnS ultrafine particles.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09K 11/00 C09K 11/00 A 11/08 ZNM 11/08 ZNMG H01L 33/00 H01L 33/00 D H05B 33/14 H05B 33/14 BF Term (reference) 3K007 AB18 DB03 FA01 4G047 AA02 AB02 AC03 AD03 BA01 BB01 BC02 BD03 4H001 CA02 CC13 XA08 XA16 XA30 XA34 XA40 XA48 4H050 AA05 AB91 5F041 CA05 CA41

Claims (6)

[Claims] 1. A semiconductor ultrafine particle comprising a polyalkylene glycol residue bonded to a semiconductor crystal surface through an oxygen atom in a functional group represented by the following general formula (1). [Chemical 1] (In the general formula (1), R ¹ and R ² are each a hydrogen atom,
It represents any one selected from a hydroxyl group, an alkyl group having 8 or less carbon atoms which may have a substituent, an aryl group, an alkoxyl group and a trialkylsilyl group, and a halogen atom, and R ¹ and R ² are the same or different. May be. ) 2. R ¹ in the functional group represented by the general formula (1)
^2. The semiconductor ultrafine particles according to claim 1, wherein at least one of R ² and R ² is a hydroxyl group. 3. The semiconductor ultrafine particles according to claim 1 or 2, wherein the functional group represented by the general formula (1) and a polyalkylene glycol residue are linked via an alkylene group. 4. The semiconductor superstructure according to claim 1, wherein the semiconductor crystal is mainly composed of a II-VI group compound semiconductor composition, a III-V group compound semiconductor composition or a metal oxide semiconductor composition. Fine particles. 5. A thin film-shaped molded product containing the semiconductor ultrafine particles according to claim 1. 6. An n-phosphonoalkyl triethylene glycol ether represented by the following general formula (2). [Chemical 2] (In the general formula (2), R represents a hydrogen atom or an alkyl group having 7 or less carbon atoms, and n represents a natural number of 20 or less.)