Electrostatic Mechanism of Emission Enhancement in Hybrid Metal-semiconductor Light-emitting Heterostructures Page: 3

emission intensity of the system [6]. Similar results have also been obtained for other
systems [7].
Despite early progress in showing PL enhancement under photo-excitation,
much less progress has been made in harnessing plasmons for actual LED and LD
applications. Specifically recent work has shown an enhancement of 1.5x in
electroluminescence for an InGaN LED coupled to SPPs on silver nanoparticles
embedded within the heterostructure [8].
Using SPP coupling to produce enhancement requires that the energy of the
plasmons match that of the emission source. Unfortunately the plasmon energy is a
function of the metal used and the geometry of the metal itself. The energy of SPPs is
determined primarily by the metal used, and can be altered somewhat by the dielectric
constant of the semiconductor and the dimensionality of the metal structure. In both
cases the plasmon energy can only be lowered from the bulk energy. The lack of
tunability and resonance requirement of plasmonics limits the range of energies over
which it can be applied. This, combined with energy loss due to Joule heating at the
metal-dielectric interface by the plasmons poses a challenge for plasmonics for light
emission enhancement.
1.3 Non-resonant Enhancement and Strain Mapping
While plasmonics shows great promise for many applications, the requirement of
resonant interaction and limitations in the plasmon frequencies of available metals limit
its use for light emission enhancement. It is for this reason that I have pursued a non-
resonant method of emission enhancement. Developing such a method would provide