Tunable surface plasmons in coupled metallo-dielectric multiple layers for light-emission efficiency enhancement

The coupling of spontaneously emitted photons to surface plasmons in metal films is a promising technique to increase the efficiency of light-emitting devices. Here we propose and theoretically investigate the use of metallo-dielectric multiple layers to engineer the surface-plasmon density of states, so as to introduce tunable resonances in the emission efficiency through the anticrossing of modes localized on neighboring interfaces. To illustrate, large enhancements in the radiative recombination rate at tunable wavelengths are predicted for a GaN-based light-emitting device, using a Ag/Si3N4/Au/Si3N4 structure with different combinations of the layers thicknesses. (c) 2005 American Institute of Physics.