Density effect of Ag/SiO2 core-shell nanoparticles on optical properties of InGaN/GaN light-emitting diodes

We experimentally investigated the density effect of Ag/SiO2 core-shell nanoparticles (CSNPs) on the carrier recombination rate and photoluminescence (PL) of the InGaN/GaN light-emitting diodes (LEDs). For the high-efficiency InGaN/GaN blue LEDs, there was an optimum Ag/SiO2 CSNP density of about 15 mu m(-2). From the numerical simulations, the fast carrier recombination rate and the enhanced PL intensity are related to the enhancement of the Purcell factor and the light extraction efficiency due to the localized surface plasmon (LSP) mode. However, this plasmonic enhancement was limited at high Ag/SiO2 CSNP densities by the LSP resonance shift and ohmic loss. We expect that these results could be useful for the practical design of LSP-assisted optoelectronic devices such as LEDs, organic light-emitting diodes, and photovoltaics. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)