EAPSI: Enhancing efficiency in a nanomaterial light source for laser applications

Marvinney Claire E, Nashville TN

Investigators

Abstract

Solid-state light sources, such as lasers, can be made more efficient by correlating the physics of light emission in semiconductors, materials with light emission properties and decent conductivity, with their composition and physical structure. The goal of this project is to improve the efficiency of a promising ultraviolet light source, zinc oxide, by fabricating it in the form of a nanowire, a nano sized wire structure. Vertical nanowires, instead randomly oriented wires, are ideal for studying the link between the optical physics and the material properties. The efficiency of these nanowire light sources can be improved by decorating the wires with metal nanoparticles. The goal of this project will be to fabricate vertical nanowires and decorate with aluminum, with possible better light-emission enhancement properties than either silver or gold. This research will be conducted in collaboration with Professors Yi Chun Liu and Hai Yang Xu at Northeast Normal University in China, known around the world for fabricating vertically oriented zinc oxide nanowires for lasers applications. The vertical nanowires to be grown are similar to previously studied randomly oriented zinc oxide/magnesium oxide core/shell nanowires, where the additional photoluminescence enhancement observed is dramatically enhanced by plasmon-exciton coupling due to a silver nanoparticle coating. Alumium nanoparticles, not previously studied with zinc oxide nanowires, have a localized surface plasmon resonance (LSPR) that fully overlaps the band edge exciton emission of zinc oxide, making it more promising for photoluminescence enhancement of zinc oxide than silver nanoparticles, who's LSPR does not fully overlap zinc oxides band edge emission. In this project, magnesium oxide and zinc magnesium oxide will provide spacer layers between the plasmonic and semiconducting materials allowing for both the plasmon-exciton coupling strength to be fully studied and for optical cavity effects in the core-shell structure to create additional enhancement. Aluminum nanoparticle plasmon-exciton coupling strength will be compared to silver nanoparticle coupling strength. This NSF EAPSI award is funded in collaboration with the Chinese Ministry of Science and Technology.