Monodisperse core/shell and other complex structured nanocrystals and methods of preparing the same

Patent metadata

Field	Value
Publication number	US-9850426-B2
Application number	US-201414525721-A
Country	US
Kind code	B2
Filing date	Oct 28, 2014
Priority date	Jan 22, 2003
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

The present invention provides new compositions containing nearly monodisperse colloidal core/shell semiconductor nanocrystals with high photoluminescence quantum yields (PL QY), as well as other complex structured semiconductor nanocrystals. This invention also provides new synthetic methods for preparing these nanocrystals, and new devices comprising these compositions. In addition to core/shell semiconductor nanocrystals, this patent application also provides complex semiconductor nanostructures, quantum shells, quantum wells, doped nanocrystals, and other multiple-shelled semiconductor nanocrystals.

First claim

The invention claimed is:

1. A composition comprising nanocrystalline, core/shell/shell quantum wells, wherein:
the quantum wells comprise a core material, a first shell material overcoating the core material, and a second shell material overcoating the first shell material;
the core material comprises a stable, nanometer-sized inorganic solid;
the first shell material and the second shell material are independently selected from a II/VI compound or a III/V compound;
the band gap of the first shell material is less than the band gap of the core material and less than the band gap of the second shell material; and
the as-prepared quantum wells exhibit a photoluminescence that is substantially limited to a bandgap emission, with a room temperature photoluminescence quantum yield from 10% to 60%.

2. The composition of claim 1 , wherein the core material comprises a II/VI compound or a III/V compound.

3. The composition of claim 1 , wherein the core comprises an insulator.

4. The composition of claim 1 , wherein the quantum wells comprise CdS/CdSe/CdS, CdS/CdSe/ZnSe, CdS/CdSe/ZnS, ZnSe/CdSe/CdS, ZnSe/CdSe/ZnSe, ZnSe/CdSe/ZnS, ZnS/CdSe/ZnS, ZnS/CdSe/CdS, ZnS/CdSe/ZnSe, ZnS/CdS/ZnS, ZnS/ZnSe/ZnS, CdS/InP/CdS, CdS/InP/ZnSe, CdS/InP/ZnS, ZnSe/InP/ZnSe, ZnSe/InP/CdS, ZnSe/InP/ZnS, ZnS/InP/ZnS, ZnS/InP/CdS, ZnS/InP/ZnSe, CdS/InAs/CdS, CdS/InAs/ZnSe, CdS/InAs/ZnS, ZnSe/InAs/ZnSe, ZnSe/InAs/CdS, ZnSe/InAs/ZnS, ZnS/InAs/ZnS, ZnS/InAs/CdS, ZnS/InAs/ZnSe, CdSe/InAs/CdSe, CdSe/InAs/CdS, CdSe/InAs/ZnS, CdSe/InAs/ZnSe, InAs/InP/CdS, or a mixture thereof.

5. The composition of claim 1 , wherein the core material and the second shell material are the same.

6. The composition of claim 1 , wherein the second shell material comprises two or more monolayers.

7. The composition of claim 1 , wherein the quantum wells comprise CdS/CdSe/CdS.

8. The composition of claim 1 , wherein the core/multiple shell nanocrystals have a size distribution with a standard deviation no greater than about 15% of a mean diameter of the nanocrystals.

9. The composition of claim 1 , wherein the core/multiple shell nanocrystals have a size distribution with a standard deviation no greater than about 10% of a mean diameter of the nanocrystals.

10. The composition of claim 1 , wherein the core/multiple shell nanocrystals have a size distribution with a standard deviation no greater than about 5% of a mean diameter of the nanocrystals.

Assignees

• Univ Arkansas

Inventors

• Peng Xiaogang
• Li Jianqing
• Battaglia David
• Wang Y Andrew
• Wang Yunjun

Classifications

• H01L33/28

  Electricity · mapped topic

• C09K11/703

  with zinc or cadmium · CPC title

• H01L31/0352

  Electricity · mapped topic

• C30B7/00

  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 title

• B82Y15/00

  Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors · CPC title