US Patent 7811479 - Polymer nanocrystal quantum dot composites

http://ip.com/patent/US7811479

Typically the quantum efficiency of photodiodes and solar cells is less than 1 using conventional semiconductor materials. This patent from the University of Pennsylvania teaches a nanocrystal composite capable of producing a quantum efficiency>1 by introducing a gain through carrier multiplication. Claim 1 reads:

1. A composition, comprising:

a semiconducting polymer characterized as having a bandgap in the visible part of the electromagnetic spectrum, and

a plurality of spherical nanocrystals characterized as having a bandgap in the infrared part of the electromagnetic spectrum,

wherein the weight ratio of semiconducting polymer to nanocrystals is in the range of from more than about 95:5 to about 1000:1.