Enhanced Luminescence of InGaN Quantum Well Structures with Localized Surface Plasmon by Using Sputter-Fabricated Ag Nanoparticles in an Ionic Liquid

Small, uniform Ag nanoparticles (NPs) in ionic liquids (ILs) are synthesized via simple sputtering route. The NPs embedded in polymer film are coated on top of InGaN/GaN active multiple quantum-well light-emitting structures and their optical characteristics are compared. The InGaN structures coated with Ag NPs show a significant increase in photoluminescence efficiency, mainly caused by localized surface plasmon (LSPs) coupling. Time-resolved (TR) photoluminescence analysis demonstrates that the coupling efficiency is 47.2%. The increased luminescence is caused by good energy matching between the surface plasmon and the light emitter. The authors believe that present work takes a first step to utilize the advantages of metal NPs synthesized in ILs and has a great potential for use in various optoelectronic devices.