Blue emitting semiconductor nanocrystals and compositions and devices including same
View Patent ↗A semiconductor nanocrystal capable of emitting blue light upon excitation. Also disclosed are devices, populations of semiconductor nanocrystals, and compositions including a semiconductor nanocrystal capable of emitting blue light upon excitation. In one embodiment, a semiconductor nanocrystal capable of emitting blue light including a maximum peak emission at a wavelength not greater than about 470 nm with a photoluminescence quantum efficiency greater than about 65% upon excitation. In another 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 blue light with a photoluminescence quantum efficiency greater than about 65% upon excitation. In a further 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 comprising at least three chemical elements, wherein the semiconductor nanocrystal is capable of emitting light including a maximum peak emission in the blue region of the spectrum upon excitation.
1. A device comprising a semiconductor nanocrystal capable of emitting blue light including a maximum peak emission at a wavelength not greater than about 470 nm with a photoluminescence quantum efficiency greater than about 65% upon excitation, the semiconductor nanocrystal comprising a core/shell structure wherein the core comprises a first semiconductor material and the shell comprises a second semiconductor material, wherein the shell is disposed over at least a portion of a surface of the core.
2. A device in accordance with claim 1 wherein the semiconductor nanocrystal is capable of emitting light with a photoluminescence quantum efficiency greater than about 70% upon excitation.
3. 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.
4. 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.
5. 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, wherein the semiconductor nanocrystal is capable of emitting blue light with a photoluminescence quantum efficiency greater than about 65% upon excitation.
6. A device in accordance with claim 5 wherein the device comprises a light-emitting device.
7. A device in accordance with claim 5 wherein the first semiconductor material comprises zinc, cadmium, and selenium.
8. A semiconductor nanocrystal in accordance with claim 7 , wherein the second semiconductor material comprises Cd x Zn 1−x S wherein 0<x<1.
9. A device in accordance with claim 5 wherein the second semiconductor material comprises zinc, cadmium, and sulfur.
10. A device in accordance with claim 5 wherein the first semiconductor material comprises Zn 1−x Cd x Se, wherein 0<x<1.
11. A device in accordance with claim 5 wherein the second semiconductor material comprises Cd x Zn 1−x S wherein 0<x<1.
12. A device in accordance with claim 5 wherein the first semiconductor material comprises zinc, cadmium, and sulfur.
13. A device in accordance with claim 5 wherein the second semiconductor material comprises zinc and sulfur.
14. A device in accordance with claim 5 wherein the first semiconductor material comprises Zn x Cd 1−x S, wherein 0<x<1.
15. A device in accordance with claim 14 wherein 0<x<0.5.
16. A device in accordance with claim 14 wherein 0.05<x<0.2.
17. A device in accordance with claim 5 wherein the second semiconductor material comprises ZnS.
18. A device in accordance with claim 5 wherein the device is a light-emitting device.
19. 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 the core, the shell comprising a second semiconductor material, wherein the semiconductor nanocrystal is capable of emitting blue light with a photoluminescence quantum efficiency greater than about 65% upon excitation.
20. A device in accordance with claim 19 wherein the means for exciting the semiconductor nanocrystals comprises a light source.
21. A device in accordance with claim 19 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.
22. A device in accordance with claim 19 wherein the device is a light-emitting device.