Enhancement of the external quantum efficiency of a silicon quantum dot light-emitting diode by localized surface plasmons

A study was conducted to report the first evidence of enhanced external quantum efficiency in a Si QD (silicon quantum dot) light emitting diode (LED) resulting from the coupling between Si QDs and localized surface plasmons (LSP) and effective current tunneling into Si QDs from an Ag layer containing Ag particles inserted between the Si QD layer and Si substrate. The study proposed a Si QD LED structure with an Ag layer containing Ag particles inserted between the silicon nitride layer containing Si QDs and the Si substrate layer to keep the close distance between Si QDs and the metal layer for Si QD-LSP coupling. The resonant excitation of LSPs on the surface of nanostructured metallic particles by an incident electromagnetic field (light) causes strong light scattering and absorption, and enhanced local electromagnetic fields. LSPs also are generally used in several applications such as ultrafast switches, optical tweezers, and labeling biomolecules.