Dislocation-driven CdS and CdSe nanowire growth.
Dislocation-driven CdS and CdSe nanowire growth.
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DOI：
10.1021/nn301194v
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发表时间：
2012-04
期刊：
影响因子：
17.1
通讯作者：
Haoyu Wu;Fei Meng;Linsen Li;Song Jin;Gengfeng Zheng
中科院分区：
文献类型：
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作者：
Haoyu Wu;Fei Meng;Linsen Li;Song Jin;Gengfeng Zheng
本文报道了用H(2)辅助化学气相沉积法制备了以金为催化剂的硫化镉和硒镉纳米线(NWS)和纳米带(NRS)。在较高的系统压力下，在没有催化剂的情况下可以得到纳米棒和纳米锥。用双光束透射电子显微镜和位移孔径暗场电子显微镜研究了NW的生长机制。在合成的一维(1D)硫化镉和硫化镉纳米晶中经常观察到位错对比和扭曲轮廓，这表明在我们的实验条件下位错驱动的纳米晶生长机制是起作用的。测量并量化了位错的Burgers矢量和与之相关的EShelby扭转。我们假设，金纳米粒子提供了成核位置，以启动CDS/CdSe纳米晶的生长，并导致位错的形成，从而在低过饱和水平下继续驱动和维持一维生长。我们的研究表明，位错驱动机制也可能有助于其他一维纳米材料的生长，这些材料通常被认为是通过气-液-固机制生长的。
We report the synthesis of CdS and CdSe nanowires (NWs) and nanoribbons (NRs) with gold catalysts by H(2)-assisted chemical vapor deposition. Nanopods and nanocones were obtained without catalysts at higher system pressure. Transmission electron microscopy (TEM) studies, including two-beam TEM and displaced-aperture dark-field TEM characterization, were used to investigate the NW growth mechanism. Dislocation contrast and twist contours have been routinely observed within the synthesized one-dimensional (1D) CdS and CdSe NWs, suggesting the operation of the dislocation-driven NW growth mechanism under our experimental conditions. The Burgers vectors of dislocations and the associated Eshelby twists were measured and quantified. We hypothesize that gold nanoparticles provide nucleation sites to initiate the growth of CdS/CdSe NWs and lead to the formation of dislocations that continue to drive and sustain 1D growth at a low supersaturation level. Our study suggests that the dislocation-driven mechanism may also contribute to the growth of other 1D nanomaterials that are commonly considered to grow via the vapor-liquid-solid mechanism.