Localized surface-plasmon effects of Au NPs on UV electroluminescence properties of n-ZnO/p-GaN heterojunction light emitting diodes

Abstract

This paper demonstrates that both intensities of photoluminescence (PL) and electroluminescence (EL) from the band edge emission of ZnO submicron spheres can be improved by the use of localized surface-plasmon resonance (LSPR) Au nanoparticles (NPs) Conversely the use of LSPR reduces the green emission from the surface defect of ZnO The origin of such luminescence enhancement is attributed to the LSPR where electrons transfer between a conduction band and defect level through the LSPR Time-resolved PL measurement results reveal that the spontaneous rate is increased as a result of the coupling between ZnO excitons and Au NPs LSPR The other reason for the enhancement of PL from the near-band-edge emission of ZnO is the exciton-LSP coupling between Au NPs and ZnO A six-fold ultraviolet EL enhancement was achieved from the Au NPs decorated device Different deposited sequences of Au NPs in an n-ZnO/p-GaN layer were made to understand the selective enhancement of EL Enhancement such as the ones demonstrated in this paper should be considered in the future when designing the highly efficient solid state emitters

Date of Award	2016 Aug 17
Original language	English
Supervisor	Hsu-Cheng Hsu (Supervisor)