Plasmon-Enhanced Upconversion Luminescence in Single Nanophosphor鈥揘anorod Heterodimers Formed through Template-Assisted Self-Assembly
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- 作者：Nicholas J. Greybush ; Marjan Saboktakin ; Xingchen Ye ; Cristian Della Giovampaola ; Soong Ju Oh ; Nathaniel E. Berry ; Nader Engheta ; Christopher B. Murray ; Cherie R. Kagan
- 刊名：ACS Nano
- 出版年：2014
- 出版时间：September 23, 2014
- 年：2014
- 卷：8
- 期：9
- 页码：9482-9491
- 全文大小：638K
- ISSN：1936-086X
文摘
We demonstrate plasmonic enhancement of upconversion luminescence in individual nanocrystal heterodimers formed by template-assisted self-assembly. Lithographically defined, shape-selective templates were used to deterministically coassemble single Au nanorods in proximity to single hexagonal (尾-phase) NaYF4:Yb3+,Er3+ upconversion nanophosphors. By tailoring the dimensions of the rods to spectrally tune their longitudinal surface plasmon resonance to match the 977 nm excitation wavelength of the phosphors and by spatially localizing the phosphors in the intense near-fields surrounding the rod tips, several-fold luminescence enhancements were achieved. The enhancement effects exhibited a strong dependence on the excitation light鈥檚 polarization relative to the rod axis. In addition, greater enhancement was observed at lower excitation power densities due to the nonlinear behavior of the upconversion process. The template-based coassembly scheme utilized here for plasmonic coupling offers a versatile platform for improving our understanding of optical interactions among individual chemically prepared nanocrystal components.