Enhanced optical properties of nanopillar light-emitting diodes by coupling localized surface plasmon of Ag/SiO2 nanoparticles

We fabricated nanopillar light-emitting diodes (LEDs) embedded with Ag/SiO2 nanoparticles, and investigated the energy coupling processes between the localized surface plasmons of nanoparticles and the active quantum well regions of nanopillar LEDs. These nanoparticle-embedded nanopillar LEDs showed considerable increases in photoluminescence and electroluminescence intensities, compared with reference nanopillar LEDs. The observed optical enhancement was explained by the increased spontaneous emission rate caused by energy coupling from excitons in the InGaN/GaN quantum well active region of the LEDs to the localized surface plasmon modes of the Ag/SiO2 nanoparticles. A strongly enhanced characteristic photoluminescence decay also confirmed such an explanation. (C) 2015 The Japan Society of Applied Physics