Synthesis and Optical Properties of Type II CdTe/CdS Core/Shell Quantum Dots in Aqueous Solution via Successive Ion Layer Adsorption and Reaction

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• 作者：Qinghui Zeng ; Xianggui Kong ; Yajuan Sun ; Youlin Zhang ; Langping Tu ; Jialong Zhao ; Hong Zhang
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：June 12, 2008
• 年：2008
• 卷：112
• 期：23
• 页码：8587 - 8593
• 全文大小：1307K
• 年卷期：v.112,no.23(June 12, 2008)
• ISSN：1932-7455

文摘

3-Mercaptopropionic acid stabilized CdTe/CdS core/shell quantum dots (QDs) were prepared in an aqueous solution following the synthetic route of successive ion layer adsorption and reaction. The photoluminescence quantum yield of the CdTe QDs could reach 40%, from 8% of the bare core, via the control of the shell thickness. The CdTe/CdS QDs exhibited also a significant red shift of emission and excitation peaks when the shell layer grew. The experiments revealed that the CdTe/CdS QDs evolved from type I to type II core/shell structures with the increase of the shell thickness, and the evolution process is affected by the core size, shell thickness, surface quality of the core and shell, as unraveled by steady-state and time-resolved spectroscopy. The lack of photoluminescence lifetime lengthening was ascribed to the surface influence of the shell.