Observation of Considerable Upconversion Enhancement Induced by Cu2–xS Plasmon Nanoparticles

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• 作者：Donglei Zhou ; Dali Liu ; Wen Xu ; Ze Yin ; Xu Chen ; Pingwei Zhou ; Shaobo Cui ; Zhanguo Chen ; Hongwei Song
• 刊名：ACS Nano
• 出版年：2016
• 出版时间：May 24, 2016
• 年：2016
• 卷：10
• 期：5
• 页码：5169-5179
• 全文大小：691K
• 年卷期：0
• ISSN：1936-086X

文摘

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 Cu_2–xS NPs/films and the utilization of LSPRs generated from semiconductor NPs as near-infrared antennas to enhance the upconversion luminescence (UCL) of NaYF₄:Yb³⁺,Er³⁺ NPs. Our results suggest that the LSPRs in Cu_2–xS NPs originate from ligand-confined carriers and that a heat treatment resulted in the decomposition of ligands and oxidation of Cu_2–xS NPs; these effects led to a decrease of the Cu²⁺/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:Yb³⁺,Er³⁺ NPs was substantially improved and exhibited extraordinary power-dependent behavior because of the energy band structure of the Cu_2–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.