Coupling single quantum dots to plasmonic nanocones: optical properties.
Coupling single quantum dots to plasmonic nanocones: optical properties.
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DOI：
10.1039/c5fd00074b
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发表时间：
2015-12
影响因子：
3.4
通讯作者：
A. Meixner;Regina Jäger;S. Jäger;A. Bräuer;Kerstin Scherzinger;J. Fulmes;Sven zur Oven Krockhaus;Dominik A. Gollmer;D. Kern;M. Fleischer
中科院分区：
文献类型：
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作者：
A. Meixner;Regina Jäger;S. Jäger;A. Bräuer;Kerstin Scherzinger;J. Fulmes;Sven zur Oven Krockhaus;Dominik A. Gollmer;D. Kern;M. Fleischer
将单个量子发射体（诸如荧光分子或量子点（QD））耦合到等离子体纳米结构是纳米光学和纳米光谱学中的重要问题，与广泛的应用相关，包括尖端增强近场光学显微镜、等离子体增强分子传感和光谱学以及纳米光子放大器或纳米激光器，仅举几例。虽然已经很好地研究了尖锐纳米天线的场增强，其增加了非常接近定位的单分子或QD的激发速率，但是到目前为止，对从这样的系统发射光子所涉及的详细物理机制的研究较少。在我们正在进行的一个研究项目中，我们试图通过构建和光谱分析几何简单的混合异质结构来解决这些问题，该异质结构由尖锐的金锥组成，其中单个量子点连接到尖端顶点。这项工作的一个重要目标是通过调整锥体的几何形状，以在标称650 nm处的核壳型CdSe/ZnS量子点的发射最大值，来调谐纵向等离子体共振。成功地区分了裸锥、纯量子点和杂化体系的荧光光谱。在接下来的步骤中，我们将进一步从实验和理论上研究耦合系统的光学性质，如荧光光谱，闪烁统计和荧光寿命的当前结果，并将它们与非耦合量子点进行比较，以获得辐射和非辐射过程的更清晰的图像。
Coupling a single quantum emitter, such as a fluorescent molecule or a quantum dot (QD), to a plasmonic nanostructure is an important issue in nano-optics and nano-spectroscopy, relevant for a wide range of applications, including tip-enhanced near-field optical microscopy, plasmon enhanced molecular sensing and spectroscopy, and nanophotonic amplifiers or nanolasers, to mention only a few. While the field enhancement of a sharp nanoantenna increasing the excitation rate of a very closely positioned single molecule or QD has been well investigated, the detailed physical mechanisms involved in the emission of a photon from such a system are, by far, less investigated. In one of our ongoing research projects, we try to address these issues by constructing and spectroscopically analysing geometrically simple hybrid heterostructures consisting of sharp gold cones with single quantum dots attached to the very tip apex. An important goal of this work is to tune the longitudinal plasmon resonance by adjusting the cones' geometry to the emission maximum of the core-shell CdSe/ZnS QDs at nominally 650 nm. Luminescence spectra of the bare cones, pure QDs and hybrid systems were distinguished successfully. In the next steps we will further investigate, experimentally and theoretically, the optical properties of the coupled systems in more detail, such as the fluorescence spectra, blinking statistics, and the current results on the fluorescence lifetimes, and compare them with uncoupled QDs to obtain a clearer picture of the radiative and non-radiative processes.