Semiconductor nanoparticle and method for producing same

• US 20050145853A1
• Filed: 12/18/2003
• Published: 07/07/2005
• Est. Priority Date: 12/19/2002
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi Software Engineering Co., Ltd. (Hitachi, Ltd.)
• Inventors: Kuwabata, Susumu, Sato, Keiichi
• Granted Patent: US 7,378,151 B2
• Time in Patent Office: Days
• US Class Current: 257/79
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01P 2002/84 by UV- or VIS- data
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C09C 1/12 Cadmium sulfoselenide
• CPC Class Codes: C09C 3/08 Treatment with low-molecular-weight non-polymer organic compounds C09C3/006, C09C3/048 take precedence
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/0894 Antimonates; Arsenates
• CPC Class Codes: C09K 11/54 containing zinc or cadmium
• CPC Class Codes: C09K 11/56 containing sulfur
• CPC Class Codes: C09K 11/565 with zinc cadmium
• CPC Class Codes: C09K 11/59 containing silicon
• CPC Class Codes: C09K 11/66 containing germanium, tin or lead
• CPC Class Codes: C09K 11/68 containing chromium, molybdenum or tungsten
• CPC Class Codes: C09K 11/88 containing selenium, tellurium or unspecified chalcogen elements
• CPC Class Codes: C09K 11/883 with zinc or cadmium
• CPC Class Codes: Y10S 977/773 Nanoparticle, i.e. structure having three dimensions of 100 nm or less
• CPC Class Codes: Y10S 977/783 Organic host/matrix, e.g. lipid
• CPC Class Codes: Y10S 977/813 Of specified inorganic semiconductor composition, e.g. periodic table group IV-VI compositions
• CPC Class Codes: Y10S 977/83 Inorganic core or cluster coated with organic or biological shell
• CPC Class Codes: Y10S 977/834 Optical properties of nanomaterial, e.g. specified transparency, opacity, or index of refraction
• CPC Class Codes: Y10S 977/904 : for medical, immunological, body treatment, or diagnosis
• CPC Class Codes: Y10S 977/949 : Radiation emitter using nanostructure
• CPC Class Codes: Y10T 428/2991 : Coated

Abstract

The invention provides a semiconductor nanoparticle comprising a semiconductor nanoparticle core on the surface of which electron-releasing groups are arranged, the semiconductor nanoparticle having a fluorescent property and water-solubility. The invention also provides a water-soluble semiconductor nanoparticle with an excellent fluorescent property that can be easily prepared by adding a surface-treating material for providing a semiconductor nanoparticle with one or more kinds of electron-releasing groups, and arranging the electron-releasing groups on the surface of the semiconductor nanoparticle core.

Claims

1. A semiconductor nanoparticle comprising a core on the surface of which electron-releasing groups are arranged, said semiconductor nanoparticle having a fluorescent property.

2. The semiconductor nanoparticle according to claim 1, wherein said electron-releasing groups are of at least one type selected from the group consisting of —

OR, —

OCH₂R, —

OCOCH₂R, —

NHR, —

N(CH₂R)₂, —

NHCOCH₂R, —

CH₂R, and —

C₆H₄R, where R is one selected from the group consisting of hydrogen and substituted or unsubstituted hydrocarbon groups.

3. The semiconductor nanoparticle according to claim 1, wherein the surface of the semiconductor nanoparticle on which the electron-releasing groups are arranged is stabilized by an ionic compound.

4. The semiconductor nanoparticle according to claim 1, wherein the ionic compound is of at least one type selected from the group consisting of ammonia, primary amines (R¹NH₂), secondary amines (R¹R²NH), tertiary amines (R¹R²R³N), quaternary ammonium compounds (R⁴R⁵R⁶R⁷N), where R¹ to R⁷ are each selected from the group consisting of hydrogen and substituted or unsubstituted hydrocarbon groups.

5. The semiconductor nanoparticle according to claim 1, wherein a material of the core of the semiconductor nanoparticle is selected from the group consisting of ZnO, ZnS, ZnSe, ZnTe, CdO, CdS, CdMnS, CdSe, CdMnSe, CdTe, CdMnTe, HgS, HgSe, HgTe, InP, InAs, InSb, InN, GaN, GaP, GaAs, GaSb, TiO₂, WO₃, PbS, PbSe, MgTe, AlAs, AlP, AlSb, AlS, Ge, and Si.

6. The semiconductor nanoparticle according to claim 1, wherein said semiconductor nanoparticle is water-soluble.

7. A process of manufacturing a semiconductor nanoparticle having a fluorescent property, said process comprising adding a surface-treating material for providing the semiconductor nanoparticle with electron-releasing groups of one or more kinds, and arranging the electron-releasing groups on the surface of the core of the semiconductor nanoparticle.

8. The process of manufacturing a semiconductor nanoparticle according to claim 7, wherein the surface-treating material for providing the surface of the semiconductor nanoparticle with electron-releasing groups is of at least one kind of nitrogenated compounds selected from the group consisting of ammonia, amines, ammoniums, nitriles, and isocyanates, or oxygenated compounds selected from the group consisting of alcohols, phenols, ketones, aldehydes, carboxylic acids, esters of organic or inorganic acids, ethers, acid amides, and acid anhydrides.

9. The process of manufacturing a semiconductor nanoparticle according to claim 7, wherein the surface-treating material for providing the surface of the semiconductor nanoparticle with an electron-releasing groups is of at least one kind selected from the group consisting of ammonia, primary amines (R¹NH₂), secondary amines (R¹R²NH), tertiary amines (R¹R²R³N), quaternary ammonium compounds (R⁴R⁵R⁶R⁷N⁺), where R¹ to R⁷ are each selected from the group consisting of hydrogen and substituted or unsubstituted hydrocarbon groups.

10. The process of manufacturing a semiconductor nanoparticle according to any one of claims 7, wherein, on the surface of a semiconductor nanoparticle modified with a thiol group, the thiol compound is ionized and isolated in an alkaline environment, and then a surface-treating material for providing electron-releasing groups is added in order to substitute a functional group.

11. The process of manufacturing a semiconductor nanoparticle according to claim 7, wherein said semiconductor nanoparticle is water-soluble.

12. A fluorescent reagent comprising a semiconductor nanoparticle having a core on the surface of which electron-releasing groups are arranged, said semiconductor nanoparticle having a fluorescent property.

14. The fluorescent agent according to claim 12, wherein said electron-releasing groups are of at least one type selected from the group consisting of —

OR, —

OCH₂R, —

OCOCH₂R, —

NHR, —

N(CH₂R)₂, —

NHCOCH₂R, —

CH₂R, and —

C₆H₄R, where R is one selected from the group consisting of hydrogen and substituted or unsubstituted hydrocarbon groups.

15. The fluorescent agent according to claim 12, wherein the surface of said semiconductor nanoparticle on which the electron-releasing groups are arranged is stabilized by an ionic compound.

16. The fluorescent agent according to claim 12, wherein the ionic compound is of at least one type selected from the group consisting of ammonia, primary amines (R¹NH₂), secondary amines (R¹R²NH), tertiary amines (R¹R²R³N), quaternary ammonium compounds (R⁴R⁵R⁶R⁷N⁺), where R¹ to R⁷ are each selected from the group consisting of hydrogen and substituted or unsubstituted hydrocarbon groups.

17. The fluorescent agent according to claim 12, wherein a material of the core of said semiconductor nanoparticle is selected from the group consisting of ZnO, ZnS, ZnSe, ZnTe, CdO, CdS, CdMnS, CdSe, CdMnSe, CdTe, CdMnTe, HgS, HgSe, HgTe, InP, InAs, InSb, InN, GaN, GaP, GaAs, GaSb, TiO₂, WO₃, PbS, PbSe, MgTe, AlAs, AlP, AlSb, AlS, Ge, and Si.

18. The fluorescent agent according to claim 12, wherein said semiconductor nanoparticle is water-soluble.

13. An optical device comprising a semiconductor nanoparticle having a core on the surface of which electron-releasing groups are arranged, said semiconductor nanoparticle having a fluorescent property.

19. The optical device according to claim 13, wherein said electron-releasing groups are of at least one type selected from the group consisting of —

OR, —

OCH₂R, —

OCOCH₂R, —

NHR, —

N(CH₂R)₂, —

NHCOCH₂R, —

CH₂R, and —

C₆H₄R, where R is one selected from the group consisting of hydrogen and substituted or unsubstituted hydrocarbon groups.

20. The optical device according to claim 13, wherein the surface of said semiconductor nanoparticle on which the electron-releasing groups are arranged is stabilized by an ionic compound.

21. The optical device according to claim 13, wherein the ionic compound is of at least one type selected from the group consisting of ammonia, primary amines (R¹NH₂), secondary amines (R¹R²NH), tertiary amines (R¹R²R³N), quaternary ammonium compounds (R⁴R⁵R⁶R⁷N⁺), where R¹ to R⁷ are each selected from the group consisting of hydrogen and substituted or unsubstituted hydrocarbon groups.

22. The optical device according to claim 13, wherein a material of the core of said semiconductor nanoparticle is selected from the group consisting of ZnO, ZnS, ZnSe, ZnTe, CdO, CdS, CdMnS, CdSe, CdMnSe, CdTe, CdMnTe, HgS, HgSe, HgTe, InP, InAs, InSb, InN, GaN, GaP, GaAs, GaSb, TiO₂, WO₃, PbS, PbSe, MgTe, AlAs, AlP, AlSb, AlS, Ge, and Si.

23. The optical device according to claim 13, wherein said semiconductor nanoparticle is water-soluble.