Abstract
First, the experimental implementations and theoretical/numerical investigations of surface plasmon (SP) coupled InGaN/GaN quantum-well light-emitting diodes (LEDs) are reviewed. If the p-GaN layer in an LED can be thin, surface metal nanoparticle (NP) is an inexpensive structure for inducing effective SP coupling. When the p-GaN layer is thick, a few metal structures, including metal protrusion, buried metal NP, and embedded metal NP, can be used for effective SP coupling. In the numerical study, an algorithm, including the feedback effect of the induced SP resonance on the radiating behavior of the source dipole, has been proposed for studying the SP coupling effects with an embedded metal NP, a surface metal NP, and a metal protrusion. Then, the theoretical formulations and numerical algorithms for evaluating the radiated power enhancement in the coupling process between two radiating dipoles and the localized surface plasmon (LSP) induced on a nearby Ag NP are built. Three mechanisms are considered in the coupling process for radiated power enhancement, including the interference of the two phase-retarded radiation contributions from the two dipoles, the interaction between the two dipoles, and the LSP resonant coupling.