Piepenbrock Marc-Oliver M, Stirner Tom, O'Neill Mary, Kelly Stephen M
Department of Chemistry, University of Hull, Hull HU6 7RX, United Kingdom.
J Am Chem Soc. 2007 Jun 20;129(24):7674-9. doi: 10.1021/ja070032n. Epub 2007 May 26.
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.
通常，化学势的尺寸依赖性被用于解释半导体纳米颗粒的生长动力学。相反，我们发现非常小的碲化镉纳米颗粒在高稀释度下仍会继续生长，其生长速率实际上与单体浓度无关，在较大颗粒的生长饱和后成核仍会继续，并且生长速率对颗粒尺寸的非线性依赖性比理论预测的要大得多。我们认为，纳米颗粒在液相中生长迅速，然后在达到取决于生长温度而非单体浓度的阈值尺寸时，随着颗粒从液相转变为晶相而饱和。当反应溶液中的碲耗尽，形成富镉表面时，光致发光量子效率会变高。
