Sunday, November 15, 2009

US Patent 7615800 - Quantum dot light emitting layer with nanoparticle conductive paths

This patent from Eastman Kodak teaches integrating two types of nanomaterials - 1) luminescent quantum dots and 2) electrically conductive nanopartilces in order to produce an inorganic LED film with enhanced brightness. Claim 1 reads:

1. An inorganic light emitting layer comprising:

(a) a plurality of light emitting cores, each core having a semiconductor material that emits light in response to recombination of holes and electrons, each such light emitting core defining a first bandgap;

(b) a semiconductor shell formed completely around each light emitting core to form core/shell quantum dots, each such semiconductor shell having a second bandgap wider than the first bandgap; and

(c) a semiconductor matrix including separate inorganic nanoparticles made of Type IV, III-V, or II-VI semiconductor material connected to the semiconductor shells to provide a conductive path through the semiconductor matrix and to each such semiconductor shell and its corresponding light emitting core so as to permit the recombination of holes and electrons, the inorganic nanoparticles having a different composition from that of the core/shell quantum dots.