Effect of Electrostatic Interactions on the Photophysical Properties of the Composites of CdTe Nanocrystals and Carbazole-Containing Polymers

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• 作者：Haizhu Sun ; Hao Zhang ; Junhu Zhang ; Yang Ning ; Tongjie Yao ; Xin Bao ; Chunlei Wang ; Minjie Li ; Bai Yang
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：February 21, 2008
• 年：2008
• 卷：112
• 期：7
• 页码：2317 - 2324
• 全文大小：224K
• 年卷期：v.112,no.7(February 21, 2008)
• ISSN：1932-7455

文摘

We demonstrated in this study that the electrostatic interaction between nanocrystals (NCs) and polymerswas dominant in the photophysical properties of their composites. This effect became more pronounced underillumination and in the presence of the carbazole moieties. The mechanism in which carbazole moietiesinfluenced the PL properties was systematically investigated by means of steady-state fluorescence, fluorescencelifetimes, and ESR spectra. Our experimental results showed that the electrostatic interactions between CdTeNCs and polymers brought defects on the surface of NCs and hence led to the involvement of surface statesin the carrier recombination process. Therefore, the composites were inclined to be oxidized when their netcharges were slightly positive or negative. The optimal light emitting ratio of NCs to polymers was at thethreshold point that NCs could be just completely transferred from the aqueous phase to the organic phasebecause the composite exhibited nearly electric neutrality at such a ratio. On the other hand, carbazole moietieshad an important influence on the intrinsic recombination process of the CdTe NC's core states due to efficientelectron transfer at the interface of the NCs and polymers.