title: Effect of SiO2 Spacer-Layer Thickness on Localized Surface Plasmon-Enhanced ZnO Nanorod Array LEDs.
abstract: Localized surface plasmon (LSP)-enhanced ultraviolet LEDs have been constructed via spin-coating Ag nanoparticles onto ZnO/SiO2 core/shell nanorod array/p-GaN heterostructures. Different from the previous reports where the dielectric spacer-layer thickness was determined only through photoluminescence (PL) characterization, the SiO2 shell thickness in this work is also optimized by actual electroluminescence (EL) measurements to maximize the enhancement. It is interesting to find that the enhancement ratios derived from PL and EL measurements demonstrate different thickness dependences on SiO2 shell: an optimal 3.5-fold PL enhancement was obtained at the SiO2 thickness of 16 nm, while an "abnormal" 7-fold EL enhancement was achieved at the thickness of 12 nm. Time-resolved spectroscopy studies, as well as theoretical estimations and numerical simulations, reveal that the higher-ratio EL enhancement stems from joint contributions, both internal-quantum-efficiency improvement induced by exciton-LSP coupling and light-extraction-efficiency improvement aroused by photon-LSP coupling.
authors.affiliation: Centre for Advanced Optoelectronic Functional Materials Research and Key Laboratory for UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University , Changchun 130024, China.|State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences , Changchun 130033, China.
authors.forename: Weizhen
authors.initials: W
authors.lastname: Liu
authors.affiliation: Centre for Advanced Optoelectronic Functional Materials Research and Key Laboratory for UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University , Changchun 130024, China.
authors.forename: Haiyang
authors.initials: H
authors.lastname: Xu
authors.affiliation: Centre for Advanced Optoelectronic Functional Materials Research and Key Laboratory for UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University , Changchun 130024, China.
authors.forename: Siyi
authors.initials: S
authors.lastname: Yan
authors.affiliation: Centre for Advanced Optoelectronic Functional Materials Research and Key Laboratory for UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University , Changchun 130024, China.
authors.forename: Cen
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Centre for Advanced Optoelectronic Functional Materials Research and Key Laboratory for UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University , Changchun 130024, China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Wang
authors.affiliation: Centre for Advanced Optoelectronic Functional Materials Research and Key Laboratory for UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University , Changchun 130024, China.
authors.forename: Chunliang
authors.initials: C
authors.lastname: Wang
authors.affiliation: Centre for Advanced Optoelectronic Functional Materials Research and Key Laboratory for UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University , Changchun 130024, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences , Changchun 130033, China.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Physics, Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Lixia
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Physics, Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Jiannong
authors.initials: J
authors.lastname: Wang
authors.affiliation: Centre for Advanced Optoelectronic Functional Materials Research and Key Laboratory for UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University , Changchun 130024, China.
authors.forename: Yichun
authors.initials: Y
authors.lastname: Liu
keywords: ZnO/SiO2 core/shell nanorod array; exciton-LSP coupling; localized surface plasmon; luminescence enhancement; photon-LSP coupling; ultraviolet LED