US Patent 7825405 - Core/shell nanocrystal heterostructure

http://www.freepatentsonline.com/7825405.html

This patent from M.I.T. teaches a variation of type-II heterostructure nanocrystals having enhanced photoconversion efficiency. Claim 1 reads:

1. A device comprising a coated nanocrystal comprising:

a core nanocrystal including a first semiconductor material;

an overcoating including a second semiconductor material on the core nanocrystal; and

an organic layer on a surface of the coated nanocrystal, wherein the first semiconductor material and the second semiconductor material are selected so that, upon excitation, one charge carrier is substantially confined to the core and the other charge carrier is substantially confined to the overcoating.