Quantum efficiency control of InGaN/GaN multi-quantum-well structures using Ag/SiO2 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 SiO2 shell. These Ag/SiO2 NPs were prepared by sol-gel method. The amount of PL intensity enhancement decreased with increasing the SiO2 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/SiO2 NPs.