Control of the optical properties of CdTe nanocrystals by selective exchange of Te with thiolate: effect of organic ligands on the formation of core-shell structures.
Control of the optical properties of CdTe nanocrystals by selective exchange of Te with thiolate: effect of organic ligands on the formation of core-shell structures.
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DOI：
10.1039/b717770d
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发表时间：
2008-04
期刊：
影响因子：
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通讯作者：
T. Tsuruoka;Rena Takahashi;K. Akamatsu;H. Nawafune
中科院分区：
文献类型：
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作者：
T. Tsuruoka;Rena Takahashi;K. Akamatsu;H. Nawafune
研究了CdTe纳米晶在有机相中与硫醇分子的选择性表面交换反应中光学性质的变化，探讨了有机配体的作用机理。该反应是介导的Te阴离子的解离通过在空气中从CdTe纳米晶体的氧化，然后由硫醇盐分子以1：1的化学计量的方式连接。这导致在一个逐步的壳的形成和相应的减少的荧光CdTe核心的大小，这引起了在可见光区的吸收边和发射波长的蓝移。一个系统的研究，包括添加不同浓度的配体显示，碲解离是该过程的速率决定步骤和蓝移的程度是显着依赖于存在的有机配体的量。该过程还可以通过添加过量的硫醇盐配体来动力学控制，从而允许在环境条件下系统地调节纳米晶体的发射性质。
Changes in the optical properties of CdTe nanocrystals through selective surface exchange reaction with thiolate molecules in the organic phase are studied with an aim to investigate the mechanism and the role of organic ligands. The reaction was mediated by dissociation of Te anions via oxidation in air from CdTe nanocrystals, followed by attachment of thiolate molecules in a 1:1 stoichiometric manner. This results in a gradual shell formation and a corresponding decrease in the size of the fluorescent CdTe cores, which induces a blue shift of both the absorption edge and emission wavelength in the visible region. A systematic study including the addition of ligands at different concentrations revealed that Te dissociation is the rate-determining step for the process and the degree of blue shift is significantly dependent on the amount of organic ligands present. The process could also be kinetically controlled through the addition of an excess amount of thiolate ligands, allowing systematic tuning of the emission properties of nanocrystals under ambient conditions.