Surface Plasmon Coupling of Ag Nanoparticles with InGaN/GaN Quantum Wells for Enhancing the Emission Efficiency of Light-Emitting Devices

The application of surface metal nanoparticles (NPs) to a light-emitting diode for producing surface plasmon (SP) coupling with its quantum wells (QWs) is a simple and effective technique to increase its emission efficiency. However, the control of the hot spot geometry in the SP coupling process for maximizing its effect is not well understood yet. In this study, InGaN/GaN QW templates are overlaid with chemically synthesized Ag NPs, which are bonded onto GaN through an electrostatic force, for studying the SP coupling effects under different conditions of in situ Ag NP deformation. Through the Ag NP deformation, the geometry of the contact interface between a Ag NP and the QW template can be controlled, leading to different SP coupling behaviors. The results of a simulation study indicate that the substrate mode behavior of the localized SP resonance on a surface Ag NP, which is strongly related to the contact-interface geometry, plays a key role in controlling the SP coupling spectrum and strength.