title: Observation of Considerable Upconversion Enhancement Induced by Cu2-xS Plasmon Nanoparticles.
abstract: Localized surface plasmon resonances (LSPRs) are achieved in heavily doped semiconductor nanoparticles (NPs) with appreciable free carrier concentrations. In this paper, we present the photonic, electric, and photoelectric properties of plasmonic Cu2-xS NPs/films and the utilization of LSPRs generated from semiconductor NPs as near-infrared antennas to enhance the upconversion luminescence (UCL) of NaYF4:Yb(3+),Er(3+) NPs. Our results suggest that the LSPRs in Cu2-xS NPs originate from ligand-confined carriers and that a heat treatment resulted in the decomposition of ligands and oxidation of Cu2-xS NPs; these effects led to a decrease of the Cu(2+)/Cu(+) ratio, which in turn resulted in the broadening, decrease in intensity, and red-shift of the LSPRs. In the presence of a MoO3 spacer, the UCL intensity of NaYF4:Yb(3+),Er(3+) NPs was substantially improved and exhibited extraordinary power-dependent behavior because of the energy band structure of the Cu2-xS semiconductor. These findings provide insights into the nature of LSPR in semiconductors and their interaction with nearby emitters and highlight the possible application of LSPR in photonic and photoelectric devices.
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University , 2699 Qianjin Street, Changchun, 130012, People's Republic of China.
authors.forename: Donglei
authors.initials: D
authors.lastname: Zhou
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University , 2699 Qianjin Street, Changchun, 130012, People's Republic of China.
authors.forename: Dali
authors.initials: D
authors.lastname: Liu
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University , 2699 Qianjin Street, Changchun, 130012, People's Republic of China.|School of Chemical and Biomedical Engineering, Nanyang Technological University , 70 Nanyang Drive, Singapore 637457.
authors.forename: Wen
authors.initials: W
authors.lastname: Xu
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University , 2699 Qianjin Street, Changchun, 130012, People's Republic of China.
authors.forename: Ze
authors.initials: Z
authors.lastname: Yin
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University , 2699 Qianjin Street, Changchun, 130012, People's Republic of China.
authors.forename: Xu
authors.initials: X
authors.lastname: Chen
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University , 2699 Qianjin Street, Changchun, 130012, People's Republic of China.
authors.forename: Pingwei
authors.initials: P
authors.lastname: Zhou
authors.affiliation: College of Physics, Jilin University , 2699 Qianjin Street, Changchun, 130012, People's Republic of China.
authors.forename: Shaobo
authors.initials: S
authors.lastname: Cui
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University , 2699 Qianjin Street, Changchun, 130012, People's Republic of China.
authors.forename: Zhanguo
authors.initials: Z
authors.lastname: Chen
authors.affiliation: State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University , 2699 Qianjin Street, Changchun, 130012, People's Republic of China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Song
keywords: broadening; decrease and red-shift of LSPRs; electron injection; semiconductor plasmon nanoparticles; upconversion luminescence enhancement