Tellurium-containing nanocrystalline materials

• US 6,607,829 B1
• Filed: 07/26/2000
• Issued: 08/19/2003
• Est. Priority Date: 11/13/1997
• Status: Expired due to Term

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Kim, Sungjee, Mikulec, Frederic V., Bawendi, Moungi G.
• Primary Examiner(s): LE, HOA T
• Application Number:
  US09/625,861
• Time in Patent Office: 1,119 Days
• Field of Search: 428/570, 428/686, 428/403, 438/63, 438/93, 438/97
• US Class Current: 428/403
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 17/20 Methods for preparing sulfides or polysulfides, in general ammonium sulfides or polysulfides C01C; sulfides or polysulfides of metals, other than alkali metals, magnesium, calcium, strontium and barium, see the relevant groups of subclasses C01F or C01G, according to the metal
• CPC Class Codes: C01B 19/007 Tellurides or selenides of metals C01B19/002 takes precedence
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2002/84 by UV- or VIS- data
• CPC Class Codes: C01P 2004/04 obtained by TEM, STEM, STM or AFM
• 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 2004/80 Particles consisting of a mixture of two or more inorganic phases
• CPC Class Codes: C01P 2004/86 Thin layer coatings, i.e. the coating thickness being less than 0.1 time the particle radius
• CPC Class Codes: C01P 2006/60 Optical properties, e.g. expressed in CIELAB-values
• CPC Class Codes: C07F 9/224 Phosphorus triamides
• CPC Class Codes: C07F 9/5304 Acyclic saturated phosphine oxides or thioxides
• CPC Class Codes: C09K 11/02 Use of particular materials as binders, particle coatings or suspension media therefor
• CPC Class Codes: C09K 11/565 with zinc cadmium
• CPC Class Codes: C09K 11/883 with zinc or cadmium
• CPC Class Codes: C09K 11/885 with alkaline earth metals
• CPC Class Codes: C09K 11/892 Chalcogenides
• CPC Class Codes: C30B 29/46 Sulfur-, selenium- or tellurium-containing compounds
• 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 29/60 : characterised by shape
• 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: Y10S 977/773 : Nanoparticle, i.e. structure having three dimensions of 100 nm or less
• CPC Class Codes: Y10S 977/774 : Exhibiting three-dimensional carrier confinement, e.g. quantum dots
• CPC Class Codes: Y10S 977/777 : Metallic powder or flake
• CPC Class Codes: Y10S 977/813 : Of specified inorganic semiconductor composition, e.g. periodic table group IV-VI compositions
• CPC Class Codes: Y10S 977/824 : Group II-VI nonoxide compounds, e.g. CdxMnyTe
• CPC Class Codes: Y10S 977/832 : having specified property, e.g. lattice-constant, thermal expansion coefficient
• CPC Class Codes: Y10T 428/12035 : Fiber, asbestos, or cellulose in or next to particulate component
• CPC Class Codes: Y10T 428/12049 : Nonmetal component
• CPC Class Codes: Y10T 428/12181 : Composite powder [e.g., coated, etc.]
• CPC Class Codes: Y10T 428/12986 : Adjacent functionally defined components
• CPC Class Codes: Y10T 428/2982 : Particulate matter [e.g., sphere, flake, etc.]
• CPC Class Codes: Y10T 428/2991 : Coated
• CPC Class Codes: Y10T 428/2993 : Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]

Abstract

Tellurium-containing nanocrystallites are produced by injection of a precursor into a hot coordinating solvent, followed by controlled growth and annealing. Nanocrystallites may include CdTe, ZnTe, MgTe, HgTe, or alloys thereof. The nanocrystallites can photoluminesce with quantum efficiencies as high as 70%.

Claims

1. A population of nanocrystallites comprising a plurality of nanocrystallites, each nanocrystallite including:

a nanocrystalline core comprising MTe, wherein M is selected from the group consisting of Cd, Zn, Mg, and Hg; and

an overcoating of a semiconductor material on a surface of the core,

wherein the plurality of cores is monodisperse.

2. The population according to claim 1, wherein each nanocrystallite photoluminesces with a quantum efficiency of at least 20%.

3. The population according to claim 1, wherein each nanocrystallite photoluminesces with a quantum efficiency of at least 40%.

4. The population according to claim 1, wherein each nanocrystallite photoluminesces with a quantum efficiency of at least 60%.

5. The population according to claim 1, wherein each nanocrystallite photoluminesces with a quantum efficiency of at least ₇0%.

6. The population according to claim 1, wherein the plurality of cores has a size distribution having a standard deviation no greater than 15% of a mean diameter of the population.

7. The population according to claim 1, wherein each core comprises CdTe.

8. The population of claim 1, wherein each core photoluminesces at a wavelength in the range of 435 to 800 nm.

9. The population of claim 1 wherein each overcoating comprises ZnS.

10. The population of claim 1 wherein each overcoating comprises ZnSe.

11. The population of claim 1 wherein each overcoating comprises CdSe.

12. The population according to claim 1, wherein the FWHM is 45 nm or less.

13. The population according to claim 12, wherein the FWHM is 20 nm or less.

14. The population according to claim 12, wherein the FWHM is 15 nm or less.

15. The population according to claim 1, wherein the plurality of cores has a size distribution having standard deviation no greater than 10% of a mean diameter of the population.

16. The population according to claim 1, wherein the core is a member of a population having a size distribution with a standard deiation no greater than 5% of a mean diameter of the population.

17. A population of nanocrystallites comprising a plurality of nanocrystallites, each nanocrystallite including:

a nanocrystalline core comprising MTe, wherein M is selected from the group consisting of Cd, Zn, Mg, and Hg, and

an overcoating of a semiconductor material on a surface of the core wherein the plurality of cores is monodisperse, and each core photoluminesces at a wavelength in the range of 435 to 800 nm.

18. The population of claim 17 wherein each core comprises CdTe.

19. The population of claim 17, wherein the plurality of cores has a size distribution having a standard deviation no greater than 10% of a mean diameter of the population.

20. The population of claim 17, wherein the plurality of cores has a size distribution having a standard deviation no greater than 5% of a mean diameter of the population.

21. The population of claim 17, wherein each overcoating comprises ZnS.

22. The population of claim 17, wherein each overcoating comprises ZnSe.

23. The population of claim 17, wherein each overcoating comprises CdSe.

24. The population of claim 17, wherein each nanocrystallite photoluminesces with a quantum efficiency of at least 20%.

25. The population of claim 17, wherein each nanocrystallite photoluminesces with a quantum efficiency of at least 40%.

26. The population of claim 17, wherein each nanocrystallite photoluminesces with a quantum efficiency of at least 60%.

27. A population of nanocrystallites comprising a plurality of nanocrystallites, each nanocrystallite including:

a nanocrystalline core comprising MTe, wherein M is selected from the group consisting of Cd, Zn, Mg, and Hg, and

an overcoating of a semiconductor material on a surface of the core, wherein the plurality of cores is monodisperse and each core photoluminesces with a full-width at half maximum (FWHM) of 70 nm or less.

28. The population according to claim 27, wherein the FWHM is 45 nm or less.

29. The population according to claim 27, wherein the FWHM is 20 nm or less.

30. The population according to claim 27, wherein the FWHM is 15 nm or less.

31. The population of claim 27, wherein the plurality of cores has a size distribution having a standard deviation no greater than 10% of a mean diameter of the population.

32. The population of claim 27, wherein the plurality of cores has a size distribution having a standard deviation no greater than 5% of a mean diameter of the popuation.

33. The population of claim 27, wherein the each nanocrystallite photoluminesces with a quantum efficiency of at least 20%.

34. The population of claim 27 wherein each core comprises CdTe.