Coated semiconductor nanocrystals and products including same

Patent metadata

Field	Value
Publication number	US-10734546-B2
Application number	US-201815984144-A
Country	US
Kind code	B2
Filing date	May 18, 2018
Priority date	Nov 22, 2011
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

A coated quantum dot is provided wherein the quantum dot is characterized by having a solid state photoluminescence external quantum efficiency at a temperature of 90° C. or above that is at least 95% of the solid state photoluminescence external quantum efficiency of the semiconductor nanocrystal at 25° C. Products including quantum dots described herein are also disclosed.

First claim

What is claimed is:

1. A quantum dot comprising:
a core quantum dot comprising a Group II-VI semiconductor material, an alloy thereof, or a mixture thereof;
a first semiconductor shell consisting of ZnS or ZnSe; and
a second semiconductor shell comprising a second semiconductor material over the first semiconductor shell, wherein the second semiconductor material is different from the first semiconductor shell,
the second semiconductor material comprises a ternary or quaternary alloy of a Group II-VI compound, and wherein the core quantum dot comprises MX wherein M is cadmium, zinc, or a mixture thereof and X is sulfur, selenium, tellurium, or a combination thereof.

2. The quantum dot of claim 1 , wherein the quantum dot comprises a third shell comprising a third semiconductor material, wherein the third shell has a bandgap that is the same as or greater than that of the first shell.

3. The quantum dot of claim 1 , wherein the core quantum dot comprises zinc.

4. The quantum dot of claim 1 , wherein the core quantum dot comprises ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, or a mixture or an alloy thereof, and the second semiconductor material comprises zinc and sulfur.

5. The quantum dot of claim 1 wherein the first shell has a bandgap that is greater than that of the core quantum dot.

6. The quantum dot of claim 1 , wherein the first shell consists of ZnSe and the second shell comprises zinc and sulfur.

7. The quantum dot of claim 1 wherein the first semiconductor shell has a thickness from about 1 to about 20 monolayers.

8. The quantum dot of claim 1 wherein the second semiconductor shell has a thickness from about 1 to about 25 monolayers.

9. Quantum dots comprising a quantum dot core with a first coating consisting of a zinc chalcogenide on an outer surface of the quantum dot core and a second coating comprising a second semiconductor material and disposed over the first coating,
wherein the quantum dot core comprises a Group II-VI semiconductor material, an alloy thereof, or a mixture thereof;
wherein the zinc chalcogenide is ZnS or ZnSe,
wherein the second semiconductor material is different from the zinc chalcogenide of the first coating, and
the second semiconductor material comprises a ternary or quaternary alloy of a Group II-VI compound, and wherein the quantum dot core comprises MX wherein M is cadmium, zinc, or a mixture thereof and X is sulfur, selenium, tellurium, or a combination thereof.

10. The quantum dots of claim 9 , wherein the quantum dot core comprises zinc.

11. The quantum dots of claim 9 , wherein the quantum dot core comprises ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, or a mixture or an alloy thereof, and the second semiconductor material comprises zinc and sulfur.

12. The quantum dots of claim 9 , wherein the quantum dot core comprises a material different from the first coating.

13. The quantum dots of claim 9 , wherein the first coating has a bandgap that is greater than that of the quantum dot core.

14. The quantum dots of claim 9 , wherein the first coating consists of ZnSe and the second semiconductor material comprises zinc and sulfur.

15. The quantum dots of claim 9 , wherein the quantum dots has no more than 15% rms deviation from mean diameter.

16. The quantum dots of claim 9 , wherein the quantum dots has no more than 10% rms deviation from mean diameter.

17. The quantum dots of claim 9 , wherein the quantum dots has a full width half maximum (FWHM) of emission peak within a range of less than or equal to about 40 nm.

18. A ink comprising the quantum dots of claim 9 and a liquid vehicle, wherein the liquid vehicle comprises an organic solvent and the quantum dots are configured to be dispersed in the organic solvent.

19. The ink of claim 17 , wherein the liquid vehicle comprises a composition including one or more functional groups or units that are capable of being cross-linked.

20. An electronic device comprising the quantum dots of claim 9 .

21. The quantum dot of claim 9 , wherein the quantum dot comprises a third coating comprising a third semiconductor material, wherein the third coating has a bandgap that is the same as or greater than that of the first coating.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Breen Craig
• Liu Wenhao

Classifications

• H10P14/3461

  Nanoparticles · CPC title

• H10P14/3431

  Selenides · CPC title

• H10P14/3428

  Sulfides · CPC title

• H10P14/3402

  characterised by the chemical composition · CPC title

• H10P14/2922

  being non-crystalline insulating materials, e.g. glass or polymers · CPC title