Single-Nanocrystal Photoluminescence Spectroscopy Studies of Plasmon鈥揗ultiexciton Interactions at Low Temperature
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- 作者：Young-Shin Park ; Yagnaseni Ghosh ; Ping Xu ; Nathan H. Mack ; Hsing-Lin Wang ; Jennifer A. Hollingsworth ; Han Htoon
- 刊名：The Journal of Physical Chemistry Letters
- 出版年：2013
- 出版时间：May 2, 2013
- 年：2013
- 卷：4
- 期：9
- 页码：1465-1470
- 全文大小：424K
- 年卷期：v.4,no.9(May 2, 2013)
- ISSN：1948-7185
文摘
Using thick-shell or 鈥済iant鈥?CdSe/CdS nanocrystal quantum dots (g-NQDs), characterized by strongly suppressed Auger recombination, we studied the influence of plasmonic interactions on multiexciton emission. Specifically, we assessed the separate effects of plasmonic absorption and plasmonic emission enhancement by a systematic analysis of the pump fluence dependence of low-temperature photoluminescence (low-T PL) derived from individual CdSe/CdS g-NQDs deposited on nanoroughened silver films. Our study reveals that (1) the multiexciton (MX) emissions in g-NQD coupled to silver films were enhanced not only through the creation of more excitons via enhancement of absorption but also through the direct modification of the competition between the radiative and nonradiative recombination processes of MXs; (2) strong enhancement in absorption is not necessary for strong multiexciton emission; and (3) the emission of MXs can become stronger with the increase of multiexciton order. We also exploited the strong enhancement of MX emission to perform second-order photon correlation and cross-correlation experiments using very low pump fluences and observed a strong photon bunching that decays with increasing pump fluence.