Wednesday, July 16, 2008

US Patent 7399429 - III-V nanocrystal with >25% quantum efficiency

This patent from Evident Technologies teaches a metal coated nanocrystal composition with high quantum efficiencies. Although earlier quantum dot core-shell structures with similar efficiencies were earlier patented (see US 7,125,605) the metal coating in this configuration offers the advantage of increased chemical stability. Claim 1 reads:

1. A semiconductor nanocrystal complex comprising:

a semiconductor nanocrystal core comprising a III-V semiconductor material, and

a metal layer formed on at least a portion of an outer surface of the semiconductor nanocrystal core, wherein the semiconductor nanocrystal complex is electronically and chemically stable with a luminescent quantum yield of at least 25%.