Semiconductor nanocrystals and compositions and devices including same

Patent metadata

Field	Value
Publication number	US-9444008-B2
Application number	US-201414246275-A
Country	US
Kind code	B2
Filing date	Apr 7, 2014
Priority date	Nov 21, 2006
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

A semiconductor nanocrystal including a core comprising a first semiconductor material comprising at least three chemical elements and a shell disposed over at least a portion of the core, the shell comprising a second semiconductor material, wherein the semiconductor nanocrystal is capable of emitting light with an improved photoluminescence quantum efficiency. Also disclosed are populations of semiconductor nanocrystals, compositions and devices including a semiconductor nanocrystal capable of emitting light with an improved photoluminescence quantum efficiency. In one embodiment, a semiconductor nanocrystal includes a core comprising a first semiconductor material comprising at least three chemical elements and a shell disposed over at least a portion of the core, the shell comprising a second semiconductor material, wherein the semiconductor nanocrystal is capable of emitting light upon excitation with a photoluminescence quantum efficiency greater than about 65%. In another embodiment, a semiconductor nanocrystal includes a core comprising a first semiconductor material comprising zinc, cadmium, and sulfur and a shell disposed over at least a portion of the core, the shell comprising a second semiconductor material. In a further embodiment, a semiconductor nanocrystal includes a core comprises a first semiconductor material comprising at least three chemical elements and a shell disposed over at least a portion of the core, the shell comprising a second semiconductor material comprising at least three chemical elements, wherein the semiconductor nanocrystal is capable of emitting light with a photoluminescence quantum efficiency greater than about 60% upon excitation. In a further embodiment, a semiconductor nanocrystal including a core comprises a first semiconductor material comprising zinc, cadmium, and selenium and a shell disposed over at least a portion of the core, the shell comprising a second semiconductor material, wherein the semiconductor nanocrystal is capable of emitting light with a photoluminescence quantum efficiency greater than about 60% upon excitation.

First claim

What is claimed is:

1. A device comprising a semiconductor nanocrystal including a core comprising a first semiconductor material comprising at least three chemical elements and a shell disposed over at least a portion of a surface of the core, the shell comprising a second semiconductor material, wherein the semiconductor nanocrystal is capable of emitting light upon excitation with a photoluminescence quantum efficiency greater than about 65%.

2. A device comprising a layer comprising a plurality of semiconductor nanocrystals and means for exciting the semiconductor nanocrystals, wherein at least a portion of the semiconductor nanocrystals comprise a semiconductor nanocrystal including a core comprising a first semiconductor material comprising at least three chemical elements and a shell disposed over at least a portion of a surface of the core, the shell comprising a second semiconductor material, wherein the semiconductor nanocrystal is capable of emitting light upon excitation with a photoluminescence quantum efficiency greater than about 65%.

3. A device including a semiconductor nanocrystal including a core comprising a first semiconductor material comprising at least three chemical elements and a shell disposed over at least a portion of the core, the shell comprising a second semiconductor material comprising at least three chemical elements, wherein the semiconductor nanocrystal is capable of emitting light with a photoluminescence quantum efficiency greater than about 60% upon excitation.

4. A device comprising a layer comprising plurality of semiconductor nanocrystals and means for exciting the semiconductor nanocrystals, wherein at least a portion of the semiconductor nanocrystals comprise a core comprising a first semiconductor material comprising at least three chemical elements and a shell disposed over at least a portion of the core, the shell comprising a second semiconductor material comprising at least three chemical elements, wherein the semiconductor nanocrystal is capable of emitting light with a photoluminescence quantum efficiency greater than about 60% upon excitation.

5. A device in accordance with claim 1 wherein the semiconductor nanocrystal is capable of emitting light with a photoluminescence quantum efficiency greater than about 80% upon excitation.

6. A device in accordance with claim 1 wherein the semiconductor nanocrystal is capable of emitting light with a photoluminescence quantum efficiency greater than about 90% upon excitation.

7. A device in accordance with claim 1 wherein the semiconductor nanocrystal is capable of emitting light with a photoluminescence quantum efficiency greater than about 95% upon excitation.

8. A device in accordance with claim 1 wherein the first semiconductor material comprises zinc, cadmium, and sulfur.

9. A device in accordance with claim 1 wherein the second semiconductor material comprises zinc and sulfur.

10. A device in accordance with claim 1 wherein the light includes a maximum peak emission with a full width at half maximum of not more than 40 nm.

11. A device in accordance with claim 1 wherein the light includes a maximum peak emission with a full width at half maximum of not more than 30 nm.

12. A device in accordance with claim 1 wherein the light includes a maximum peak emission with a full width at half maximum of not more than 20 nm.

13. A device in accordance with claim 1 wherein the device is a light-emitting device.

14. A device in accordance with claim 1 wherein the device is a display device.

15. A device in accordance with claim 2 wherein the means for exciting the semiconductor nanocrystals comprises a light source.

16. A device in accordance with claim 2 wherein the means for exciting the semiconductor nanocrystals comprises a first electrode disposed on a substrate and a second electrode opposed to the first electrode and the layer comprising semiconductor nanocrystals is disposed between the two electrodes and in electrical communication therewith.

17. A device in accordance with claim 3 wherein the light includes a maximum peak emission with a full width at half maximum of not more than 40 nm.

18. A device in accordance with claim 3 wherein the device is a light-emitting device.

19. A device in accordance with claim 3 wherein the first semiconductor material comprises zinc, cadmium, and selenium.

20. A device in accordance with claim 4 wherein the first semiconductor material comprises zinc, cadmium, and selenium.

21. A device in accordance with claim 3 wherein the device is a display device.

Assignees

• Qd Vision Inc

Inventors

• Ramprasad Dorai
• Breen Craig
• Steckel Jonathan S

Classifications

• H10D62/826

  comprising only Group II-VI materials heterojunctions, e.g. CdTe/HgTe heterojunctions · CPC title

• H10H20/823

  comprising only Group II-VI materials, e.g. ZnO · CPC title

• H10H20/811

  having quantum effect structures or superlattices, e.g. tunnel junctions · CPC title

• H10H20/812 Primary

  within the light-emitting regions, e.g. having quantum confinement structures · CPC title

• H01L33/28 Primary

  Electricity · mapped topic