Synthesis and Optical Properties of Type II CdTe/CdS Core/Shell Quantum Dots in Aqueous Solution via Successive Ion Layer Adsorption and Reaction
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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DOI：
10.1021/jp711395f
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发表时间：
2008-05
影响因子：
3.7
通讯作者：
Q. Zeng;X. Kong;Ya-juan Sun;Youlin Zhang;Langping Tu;Jialong Zhao;Hong Zhang
中科院分区：
文献类型：
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作者：
Q. Zeng;X. Kong;Ya-juan Sun;Youlin Zhang;Langping Tu;Jialong Zhao;Hong Zhang
采用连续离子层吸附反应的合成路线，在水溶液中制备了3-巯基丙酸稳定的CdTe/CDS核壳量子点。通过控制壳层厚度，可以使光致发光量子产率从裸芯的8%提高到40%。随着壳层的生长，CdTe/CDS量子点的发射和激发峰也发生了显著的红移。实验表明，随着壳层厚度的增加，CdTe/CDS量子点从I型结构演化为II型核/壳结构，并且通过稳态和时间分辨光谱揭示了演化过程受核的尺寸、壳层厚度、核和壳的表面质量的影响。没有光致发光寿命的延长是由于壳层表面的影响。
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.