Fluorescence Lifetime and Blinking of Individual Semiconductor Nanocrystals on Graphene

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• 作者：Beno卯t Rogez ; Heejun Yang ; Eric Le Moal ; Sandrine L茅v锚que-Fort ; Elizabeth Boer-Duchemin ; Fei Yao ; Young-Hee Lee ; Yang Zhang ; K. David Wegner ; Niko Hildebrandt ; Andrew Mayne ; G茅rald Dujardin
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：August 14, 2014
• 年：2014
• 卷：118
• 期：32
• 页码：18445-18452
• 全文大小：394K
• ISSN：1932-7455

文摘

A new class of optoelectronic nanodevices consisting of 0D semiconductor nanocrystals and 2D single graphene layers is attracting much attention. In particular, such a system may be used to investigate and control the transfer of energy and charge in low-dimensional systems. To this end, the fluorescence dynamics of individual colloidal quantum dots (QDs) on graphene are investigated on both the 10^鈥?鈥?0^鈥? s time scale (fluorescence lifetime) and the 10⁰鈥?0² s time scale (blinking statistics) in this paper. We find that (i) a nonradiative energy transfer rate of 鈮? 脳 10⁸ s^鈥? is obtained from the reduced lifetimes of QDs on graphene as opposed to those on insulating substrates such as glass; (ii) QDs still exhibit fluorescence intermittency (鈥渂linking鈥? on graphene; (iii) the cumulative distribution functions of the 鈥渙ff鈥?times may be described by power-law statistics; (iv) QD coupling to graphene increases the time spent in the 鈥渙n鈥?state while the time spent in the 鈥渙ff鈥?state remains relatively unchanged; and (v) the fluorescence emission spectrum of the QDs is practically unaltered by the QD鈥揼raphene coupling.