Passivated nanoparticles, method of fabrication thereof, and devices incorporating nanoparticles

• US 6,906,339 B2
• Filed: 09/04/2002
• Issued: 06/14/2005
• Est. Priority Date: 09/05/2001
• Status: Expired due to Term

• Current Assignee: Rensselaer Polytechnic Institute
• Original Assignee: Rensselaer Polytechnic Institute
• Inventors: Dutta, Partha
• Primary Examiner(s): Zarabian, Amir
• Assistant Examiner(s): Soward, Ida M.
• Application Number:
  US10/233,587
• Publication Number:
  US 20030047816A1
• Time in Patent Office: 1,014 Days
• Field of Search: 257/9, 257/40, 427/4, 117/4, 977/DIG.1, 437/233
• US Class Current: 257/40
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 19/007 Tellurides or selenides of metals C01B19/002 takes precedence
• CPC Class Codes: C01G 21/21 Sulfides
• CPC Class Codes: C01P 2004/52 highly monodisperse size distribution
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: C09D 11/52 Electrically conductive inks
• CPC Class Codes: C09D 5/028 Pigments; Filters
• CPC Class Codes: C09D 5/24 Electrically-conducting paints conductive materials H01B1/00
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: C30B 29/40 AIIIBV compounds wherein A is B, Al, Ga, In or Tl and B is N, P, As, Sb or Bi
• CPC Class Codes: C30B 29/48 AIIBVI compounds wherein A is Zn, Cd or Hg, and B is S, Se or Te
• CPC Class Codes: C30B 29/605 Products containing multiple oriented crystallites, e.g. columnar crystallites
• CPC Class Codes: C30B 7/00 Single-crystal growth from solutions using solvents which are liquid at normal temperature, e.g. aqueous solutions from molten solvents C30B9/00; by normal or gradient freezing C30B11/00; under a protective fluid C30B27/00
• CPC Class Codes: C30B 7/14 the crystallising materials being formed by chemical reactions in the solution
• CPC Class Codes: H01L 21/02521 Materials
• CPC Class Codes: H01L 21/02568 Chalcogenide semiconducting materials not being oxides, e.g. ternary compounds
• CPC Class Codes: H01L 21/02601 Nanoparticles fullerenes H10K85/211
• CPC Class Codes: H01L 21/02628 using solutions
• CPC Class Codes: H01L 21/02664 Aftertreatments planarisation in general H01L21/304
• CPC Class Codes: H10K 50/11 : characterised by the electroluminescent [EL] layers
• CPC Class Codes: Y10S 977/778 : within specified host or matrix material, e.g. nanocomposite films
• CPC Class Codes: Y10S 977/786 : Fluidic host/matrix containing nanomaterials
• CPC Class Codes: Y10S 977/813 : Of specified inorganic semiconductor composition, e.g. periodic table group IV-VI compositions
• CPC Class Codes: Y10S 977/835 : Chemical or nuclear reactivity/stability of composition or compound forming nanomaterial
• CPC Class Codes: Y10S 977/847 : Surface modifications, e.g. functionalization, coating
• CPC Class Codes: Y10S 977/856 : including etching/cutting
• CPC Class Codes: Y10S 977/888 : Shaping or removal of materials, e.g. etching
• CPC Class Codes: Y10T 428/2991 : Coated

Abstract

A plurality of semiconductor nanoparticles having an elementally passivated surface are provided. These nanoparticles are capable of being suspended in water without substantial agglomeration and substantial precipitation on container surfaces for at least 30 days. The method of making the semiconductor nanoparticles includes reacting at least a first reactant and a second reactant in a solution to form the semiconductor nanoparticles in the solution. A first reactant provides a passivating element which binds to dangling bonds on a surface of the nanoparticles to passivate the surface of the nanoparticles. The nanoparticle size can be tuned by etching the nanoparticles located in the solution to a desired size.

Claims

1. A plurality of semiconductor nanoparticles having an average size between about 2 nm and about 100 nm with a size standard deviation of less than 60 percent of the average nanoparticle size determined by photon correlated spectroscopy (PCS) method, wherein the nanoparticles have an elementally passivated surface comprising a passivating element.

2. The nanoparticles of claim 1, wherein the nanoparticles have an average size between about 2 nm and about 10 nm with a size standard deviation of between about 15 and about 30 percent of the average nanoparticle size determined by photon correlated spectroscopy (PCS) method.

3. The nanoparticles of claim 1, wherein the elementally passivated surface comprises an inorganic passivating element bound to dangling bonds.

4. The nanoparticles of claim 3, wherein:

the nanoparticles comprise a II-VI, IV-VI, or a III-V semiconductor material; and

the passivating element is selected from a group consisting of H, S, Se and Te.

5. The nanoparticles of claim 4, wherein:

the passivating element comprises sulfur; and

the nanoparticles are selected from a group consisting of CdS, PbS, ZnS and compounds thereof.

6. The nanoparticles of claim 1, wherein the nanoparticles are capable of being suspended in water without substantial agglomeration and substantial precipitation on container surfaces for at least 30 days.

7. The nanoparticles of claim 6, wherein the nanoparticles are suspended in water without substantial agglomeration and substantial precipitation on container surfaces.

8. The nanoparticles of claim 1, wherein the nanoparticles are suspended in a fluid.

9. A polishing slurry, comprising a polishing slurry fluid containing the semiconductor nanoparticles of claim 1.

10. A cleaning composition comprising a cleaning fluid containing the nanoparticles of claim 1.

11. A paint comprising a liquid base and the nanoparticles of claim 1.

12. A method of making semiconductor nanoparticles, comprising:

forming semiconductor nanoparticles of a first size in a solution; and

providing an etching liquid into the solution to etch the semiconductor nanoparticles of the first size to a second size smaller than the first size to form a plurality of semiconductor nanoparticles having an average size between about 2 nm and about 100 nm with a size standard deviation of less than 60 percent of the average nanoparticle size determined by photon correlated spectroscopy (PCS) method;

wherein the solution contains a passivating element which binds to dangling bonds on a surface of the nanoparticles to elementally passivate the surface of the nanoparticles.

13. The method of claim 12, wherein:

the solution comprises an aqueous solution; and

the etching liquid comprises hydrochloric acid.

14. The method of claim 13, wherein the step of forming semiconductor nanoparticles comprises combining a metal Group IIB or lead compound and a Group VI compound in a solvent comprising water.

15. The method of claim 14, wherein:

the metal compound comprises a Pb, Zn or Cd compound; and

the Group VI compound comprises a sulfur compound.

16. The method of claim 15, wherein:

the Pb, Zn or Cd compound comprises PbO, ZnO or CdO; and

the sulfur compound comprises ammonium sulfide.

17. The method of claim 15, wherein:

the Pb, Zn or Cd compound comprises PbCl₂, ZnCl₂ or CdCl₂; and

the sulfur compound comprises sodium sulfide.

18. The method of claim 15, wherein the solution comprises an excess amount of sulfur which binds to dangling bonds on a surface of the nanoparticles to passivate the surface of the nanoparticles.

19. The method of claim 18, wherein the sulfur compound comprises (NH₄)₂S_1+x which provides the excess amount of sulfur which binds to the dangling bonds.

20. The method of claim 18, wherein the solution contains a larger molar amount of sulfur compound than the molar amount of the Pb, Zn or Cd compound to provide the excess amount of sulfur which binds to dangling bonds.

21. The method of claim 12, wherein the nanoparticles have an average size between about 2 nm and about 10 nm with a size standard deviation of between about 15 and about 30 percent of the average nanoparticle size determined by photon correlated spectroscopy (PCS) method.

22. A plurality of semiconductor nanoparticles having an average size between about 2 nm and about 100 nm with a size standard deviation of less than 60 percent of the average nanoparticle size determined by photon correlated spectroscopy (PCS) method, wherein the nanoparticles comprise undoped semiconductor nanoparticles.

23. The nanoparticles of claim 22, wherein the nanoparticles have an average size between about 2 nm and about 10 nm with a size standard deviation of between about 15 and about 30 percent of the average nanoparticle size determined by photon correlated spectroscopy (PCS) method.

24. The nanoparticles of claim 22, wherein the nanoparticles have an elementally passivated surface comprising an inorganic passivating element bound to dangling bonds.

25. The nanoparticles of claim 24, wherein:

the nanoparticles comprise a II-VI, IV-VI, or a III-V semiconductor material; and

the passivating element is selected from a group consisting of H, S, Se and Te.

26. The nanoparticles of claim 25, wherein:

the passivating element comprises sulfur; and

the nanoparticles are selected from a group consisting of CdS, PbS, ZnS and compounds thereof.

27. The nanoparticles of claim 22, wherein the nanoparticles are capable of being suspended in water without substantial agglomeration and substantial precipitation on container surfaces for at least 30 days.

28. The nanoparticles of claim 22, wherein the nanoparticles are suspended in water without substantial agglomeration and substantial precipitation on container surfaces.

29. The nanoparticles of claim 22, wherein the nanoparticles are suspended in a fluid.

30. The nanoparticles of claim 22, wherein the nanoparticles are adapted to emit radiation of a particular peak wavelength based on a size of the nanoparticles.