Growth dynamics of CdTe nanoparticles in liquid and crystalline phases.
Growth dynamics of CdTe nanoparticles in liquid and crystalline phases.
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DOI：
10.1021/ja070032n
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发表时间：
2007-05
影响因子：
15
通讯作者：
M. Piepenbrock;T. Stirner;M. O'Neill;S. Kelly
中科院分区：
文献类型：
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作者：
M. Piepenbrock;T. Stirner;M. O'Neill;S. Kelly
通常，化学势的尺寸依赖性被用来解释半导体纳米颗粒的生长动力学。相反，我们表明，非常小的CdTe纳米粒子在高稀释度下继续生长，生长速率几乎是独立的单体浓度，成核继续增长后，较大的颗粒已经饱和，和生长速率有一个更大的非线性依赖于颗粒尺寸比理论预测。我们建议，纳米颗粒的生长是快速的液相中，然后饱和的颗粒从液体到晶体的相变在一个阈值大小，这取决于生长温度，而不是单体浓度。光致发光量子效率变高时，碲是在反应溶液中耗尽，得到一个镉富集的表面。
Normally the size dependence of the chemical potential is used to explain the growth dynamics of semiconductor nanoparticles. Instead we show that very small CdTe nanoparticles continue to grow at high dilution, the growth rate is virtually independent of monomer concentration, nucleation continues after the growth of larger particles has saturated, and the growth rate has a much greater nonlinear dependence on particle size than predicted by theory. We suggest that nanoparticle growth is fast in the liquid phase and then saturates as the particles change phase from liquid to crystal at a threshold size which depends on the growth temperature and not the monomer concentration. The photoluminescence quantum efficiency becomes high when tellurium is depleted in the reaction solution giving a cadmium enriched surface.