Kinetic Model of the Initial Stage of the Nanowire Growth
Kinetic Model of the Initial Stage of the Nanowire Growth
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DOI：
10.1007/s11182-018-1322-9
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发表时间：
2018-03-01
影响因子：
0.6
通讯作者：
Hervieu, Yu Yu
中科院分区：
文献类型：
--
作者：
Filimonov, S. N.;Hervieu, Yu Yu
提出了在垂直纳米线底部形成金字塔状凸起（基座）的动力学模型。与非活化表面区域的成核速率相比，纳米线生长早期阶段基座的形成被认为是由催化剂液滴下二维岛的更高成核速率引起的。考虑到纳米线顶部的催化剂液滴是吸附原子的强汇，用多层生长模型描述了金字塔中台阶的成核和传播动力学。结果表明，如果催化剂液滴下新层的核的出现导致下面层的部分溶解，则从金字塔生长过渡到纳米线的轴向生长是可能的。在这种情况下，形成一段纳米线侧壁，防止液滴产生的层的横向生长。
A kinetic model of the formation of pyramid-like bulges (pedestals) at the bases of vertical nanowires is proposed. The formation of the pedestals at the early stage of the nanowire growth is assumed to be induced by a higher nucleation rate of two-dimensional islands under the catalyst droplet, as compared to the nucleation rate at the non-activated surface areas. Kinetics of the nucleation and propagation of the steps in the pyramid is described with a model of the multilayer growth, taking into account that the catalyst droplet at the nanowire top is a strong sink for adatoms. It is shown that the transition from the growth of the pyramid to the axial growth of the nanowire is possible if the appearance of a nucleus of the new layer under the catalyst droplet results in a partial dissolution of the underlying layer. In this case a segment of the nanowire sidewall is formed, preventing the lateral growth of the layers generated by the droplet.