Nanomaterials Optoelectronics Laboratory (NOEL), Polymer Program, University of Connecticut,Storrs, Connecticut 06269-3136, USA.
Nano Lett. 2010 Feb 10;10(2):680-5. doi: 10.1021/nl903843g.
The role of oxygen in directing the low temperature (125 degrees C), redox-assisted, unidimensional and unidirectional growth of CdSe nanocrystals (NCs) was investigated. In the presence of oxygen, CdSe quantum dots grow selectively along their c axis with little to no change in their width. Reduction of oxygen in the growth medium results in three-dimensional growth. Moreover the one-dimensional growth was found to occur only from one of the two inequivalent polar (0001) facets, as supported by the seeded growth of Cd(x)Hg(1-x)Se onto CdSe seeds. This is in agreement with density functional theory simulations, which indicate that due to selective oxygen passivation growth can occur only along the [0001] direction. The ability to control seeded NC growth with respect to morphology and directionality opens new possibilities toward the low temperature synthesis of complex nanostructures.
研究了氧在低温（125 摄氏度）、氧化还原辅助、一维和单向生长 CdSe 纳米晶体（NCs）中的作用。在氧气存在的情况下，CdSe 量子点沿其 c 轴选择性生长，宽度几乎没有变化。生长介质中氧气的减少会导致三维生长。此外，一维生长仅发生在两个不等价的极性（0001）晶面之一上，这得到了在 CdSe 种子上接种 Cd(x)Hg(1-x)Se 的种子生长的支持。这与密度泛函理论模拟结果一致，表明由于选择性氧钝化，生长只能沿[0001]方向进行。通过控制种子 NC 生长的形态和方向性，可以为低温合成复杂纳米结构开辟新的可能性。
