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 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, wherein the semiconductor nanocrystal comprises a core comprising a first semiconductor material and a shell disposed over at least a portion of a surface of the core, the shell comprising a second semiconductor material.
2. A semiconductor nanocrystal in accordance with claim 1 wherein the photoluminescence quantum efficiency is greater than about 70% upon excitation.
3. A semiconductor nanocrystal in accordance with claim 1 wherein the photoluminescence quantum efficiency is greater than about 80% upon excitation.
4. A semiconductor nanocrystal in accordance with claim 1 wherein the photoluminescence quantum efficiency is greater than about 90% upon excitation.
5. A semiconductor nanocrystal in accordance with claim 1 wherein the photoluminescence quantum efficiency is greater than about 95% upon excitation.
6. A semiconductor nanocrystal in accordance with claim 1 wherein the photoluminescence quantum efficiency is about 100% upon excitation.
7. A semiconductor nanocrystal in accordance with claim 1 wherein the first semiconductor material comprises one or more chemical elements.
8. A semiconductor nanocrystal in accordance with claim 1 wherein the first semiconductor material comprises an alloy.
9. A semiconductor nanocrystal in accordance with claim 1 wherein the first semiconductor material comprises a homogeneous alloy.
10. A semiconductor nanocrystal in accordance with claim 1 wherein the second semiconductor material comprises an alloy.
11. A semiconductor nanocrystal in accordance with claim 1 wherein the second semiconductor material comprises a homogeneous alloy.
12. A semiconductor nanocrystal in accordance with claim 1 wherein the first semiconductor material comprises zinc, cadmium, and selenium.
13. A semiconductor nanocrystal in accordance with claim 1 wherein the second semiconductor material comprises zinc, cadmium, and sulfur.
14. A semiconductor nanocrystal in accordance with claim 1 wherein the first semiconductor material comprises Zn 1-x Cd x Se, wherein 0<x<1.
15. A semiconductor nanocrystal in accordance with claim 13 , wherein the second semiconductor material can comprise Cd x Zn 1-x S wherein 0<x<1.
16. A semiconductor nanocrystal in accordance with claim 1 wherein the maximum peak emission has a full width at half maximum of not more than 40 nm.
17. A semiconductor nanocrystal in accordance with claim 1 wherein the maximum peak emission has a full width at half maximum of not more than 30 nm.
18. A semiconductor nanocrystal in accordance with claim 1 wherein one or more ligands are attached thereto.
19. A semiconductor nanocrystal in accordance with claim 1 wherein the second semiconductor material comprises one or more chemical elements.
20. A semiconductor nanocrystal in accordance with claim 1 wherein the first semiconductor material comprises zinc, cadmium, and sulfur.
21. A semiconductor nanocrystal in accordance with claim 1 wherein the first semiconductor material comprises Zn x Cd 1-x S, wherein 0<x<1.
22. A semiconductor nanocrystal in accordance with claim 21 wherein 0<x≦0.5.
23. A semiconductor nanocrystal in accordance with claim 21 wherein 0<x≦0.3.
24. A semiconductor nanocrystal in accordance with claim 21 wherein 0.05<x<0.2.
25. A semiconductor nanocrystal in accordance with claim 21 wherein 0.1≦x≦0.15.
26. A semiconductor nanocrystal in accordance with claim 21 wherein x is from about 0.10 to about 0.12.
27. A semiconductor nanocrystal in accordance with claim 1 wherein the second semiconductor material comprises ZnS.
28. A semiconductor nanocrystal in accordance with claim 1 wherein the color of the light emitted by the semiconductor nanocrystal is longer than the color of the light emitted by the core without the shell.
29. A semiconductor nanocrystal in accordance with claim 1 wherein the shell has a thickness in a range from greater than about 0 to about 20 monolayers.
30. A semiconductor nanocrystal in accordance with claim 1 wherein the first semiconductor material comprises at least three chemical elements.
31. A semiconductor nanocrystal in accordance with claim 1 wherein the second semiconductor material comprises at least three chemical elements.