Tunable surface plasmons for emission enhancement of silicon nanocrystals using Ag-poor cermet layer

To improve the quantum efficiency from silicon nanocrystals, a structure with Ag ∕ Ag -poor cermet layers is proposed. Due to large permittivity of Ag-poor cermet and its dispersion characteristic, density of states can be enhanced at the energy much lower than the plasmon energy of Ag. By properly choosing the component of the Ag-poor cermet, the dispersion of surface plasmons can be engineered to increase radiative emission rate significantly at the emission energy of silicon nanocrystals. Effective enhancement is theoretically demonstrated using Ag, which was generally recognized as nonideal material for emission enhancement in silicon nanocrystals due to its high plasmon energy.