Quantum efficiency control of InGaN/GaN multi-quantum-well structures using Ag/SiO 2 core-shell nanoparticles

Photoluminescence (PL) efficiency increase up to 2.8 times was observed for GaN/InGaN multi-quantum-well (MQW) structures as a result of deposition of a thin layer of about 40-nm-diameter Ag nanoparticles (NPs) surrounded by SiO 2 shell. These Ag/SiO 2 NPs were prepared by sol-gel method. The amount of PL intensity enhancement decreased with increasing the SiO 2 shell thickness. PL intensity increase was accompanied by corresponding decrease of PL decay time and is ascribed to a strong coupling of MQW region to localized surface plasmons (LSPs) associated with Ag/SiO 2 NPs.