US Patent 7592618 - Multilayer core/shell nanoparticle electroluminescence

http://www.freepatentsonline.com/7592618.html

This patent from Samsung teaches providing improved efficiency electroluminescence based on multiple silicon nanoparticle layers provided with insulating shells and intermediate layers. Claim 1 reads:

1. A nanoparticle electroluminescence device comprising:

a front electrode formed of a transparent conductive material;

a rear electrode formed of a conductive material; and

an emitting layer interposed between the front electrode and the rear electrode,

wherein said emitting layers includes a plurality of nanoparticle layers, each nanoparticle layer includes a plurality of nanoparticles having a core/shell structure comprising a core formed of silicon and a shell formed of silicon oxide or silicon nitride on the surface of the core, and

wherein said emitting layers further includes insulating layers formed above and below the plurality of nanoparticle layers, and an insulating layer between adjacent nanoparticle layers among said plurality of nanoparticle layers.