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.
ACS Nano. 2016 May 24;10(5):5169-79. doi: 10.1021/acsnano.6b00649. Epub 2016 May 10.
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.
局域表面等离激元共振（LSPR）可在具有可观自由载流子浓度的重掺杂半导体纳米粒子（NPs）中实现。在本文中，我们介绍了等离子体 Cu2-xS NPs/薄膜的光子、电和光电特性，以及利用半导体 NPs 产生的 LSPR 作为近红外天线来增强 NaYF4:Yb(3+)，Er(3+) NPs 的上转换发光（UCL）。我们的结果表明，Cu2-xS NPs 中的 LSPR 源自配体限制的载流子，而热处理导致配体分解和 Cu2-xS NPs 氧化；这些效应导致 Cu(2+)/Cu(+) 比值降低，从而导致 LSPR 的展宽、强度降低和红移。在存在 MoO3 间隔物的情况下，NaYF4:Yb(3+)，Er(3+) NPs 的 UCL 强度得到了显著提高，并表现出非凡的功率依赖性行为，这是由于 Cu2-xS 半导体的能带结构所致。这些发现深入了解了半导体中 LSPR 的性质及其与附近发射器的相互作用，并突出了 LSPR 在光子和光电设备中的潜在应用。
