Enhanced ultraviolet emission from Au/Ag-nanoparticles@MgO/ZnO heterostructure light-emitting diodes: A combined effect of exciton- and photon- localized surface plasmon couplings

Localized surface plasmon (LSP)-enhanced ultraviolet light-emitting diodes (LEDs) based on a Au/MgO/ZnO metal/insulator/semiconductor heterostructure were fabricated by embedding Ag nanoparticles (Ag-NPs) into MgO dielectric layer. A similar to 6-fold electroluminescence (EL) enhancement was achieved from the Ag-NPs decorated device. Time-resolved spectroscopy studies, as well as analogue simulation and theoretical estimation based on experimental data, reveal that the internal quantum efficiency and light extraction efficiency of the heterojunction LED are increased similar to 3-fold and similar to 2-fold, respectively, as a result of the introduction of Ag LSPs. This result indicates that the observed EL enhancement originates from a combined effect of both exciton-LSP coupling and photon-LSP coupling. (C)2015 Optical Society of America