Localized Surface Plasmon Coupled Light-Emitting Diodes With Buried and Surface Ag Nanoparticles

Two sets of light-emitting diodes (LEDs) based on two epitaxial structures of different p-GaN layer thicknesses for demonstrating the effects of localized surface plasmon (LSP) coupling with the quantum wells (QWs) in the LEDs are compared. In the first set based on the epitaxial structure of thick p-GaN, to reduce the distance between the Ag nanoparticles (NPs) and QWs for increasing the LSP coupling strength, Ag NPs are filled into a hole array fabricated on the p-GaN layer. In the second set based on the epitaxial structure of thin p-GaN, Ag NPs are fabricated on the top surface of the p-GaN layer. The LSP-coupled LEDs show the significant enhancements of internal quantum efficiency and LED output intensity even though the coverage of the transparent conductor, GaZnO, red-shifts the LSP resonance peak such that the LSP resonance at the QW emission wavelength becomes weaker.