Single-Photon Emission Behavior of Isolated CdSe/ZnS Quantum Dots Interacting with the Localized Surface Plasmon Resonance of Silver Nanoparticles
Single-Photon Emission Behavior of Isolated CdSe/ZnS Quantum Dots Interacting with the Localized Surface Plasmon Resonance of Silver Nanoparticles
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DOI：
10.1021/jp207997j
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发表时间：
2011-11
影响因子：
3.7
通讯作者：
Hiroyuki Naiki;Sadahiro Masuo;S. Machida;A. Itaya
中科院分区：
文献类型：
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作者：
Hiroyuki Naiki;Sadahiro Masuo;S. Machida;A. Itaya
为了揭示单量子点与银纳米粒子（AgNPs）局域表面等离子体共振（LSPR）相互作用的激子动力学，特别是多激子动力学，我们采用单分子光谱技术结合飞秒脉冲激光激发研究了单量子点荧光的单光子发射行为.通过同时测量光子相关性（光子反聚束）、荧光强度和荧光寿命，我们发现单光子发射的概率强烈依赖于荧光寿命;也就是说，当寿命短于亚纳秒时，单光子发射的概率降低。基于对LSPR增强的辐射和非辐射衰变率的估计，提出了以下机制。在没有AgNPs的情况下，由高功率激发产生的多个激子…
To reveal the exciton dynamics, particularly multiexciton dynamics in single colloidal CdSe/ZnS quantum dots (QDs) interacting with the localized surface plasmon resonance (LSPR) of silver nanoparticles (AgNPs), we investigated the single-photon emission behavior in the fluorescence from the single QDs using a single-molecule spectroscopy technique in combination with a femtosecond-pulsed laser excitation. By applying simultaneous measurements of the photon-correlation (photon antibunching), the fluorescence intensity, and the fluorescence lifetime to the single QD near AgNPs, we revealed that the probability of single-photon emission strongly depended on the fluorescence lifetime; that is, the probability of single-photon emission decreased when the lifetime was shorter than subnanoseconds. On the basis of the estimation of both radiative and nonradiative decay rates enhanced by the LSPR, the following mechanism was suggested. In the absence of AgNPs, multiple excitons generated by a high-power excitatio...