Kim B J, Tersoff J, Kodambaka S, Reuter M C, Stach E A, Ross F M
School of Materials Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, IN 47907, USA.
Science. 2008 Nov 14;322(5904):1070-3. doi: 10.1126/science.1163494.
We measured the nucleation and growth kinetics of solid silicon (Si) from liquid gold-silicon (AuSi) catalyst particles as the Si supersaturation increased, which is the first step of the vapor-liquid-solid growth of nanowires. Quantitative measurements agree well with a kinetic model, providing a unified picture of the growth process. Nucleation is heterogeneous, occurring consistently at the edge of the AuSi droplet, yet it is intrinsic and highly reproducible. We studied the critical supersaturation required for nucleation and found no observable size effects, even for systems down to 12 nanometers in diameter. For applications in nanoscale technology, the reproducibility is essential, heterogeneity promises greater control of nucleation, and the absence of strong size effects simplifies process design.
随着硅过饱和度的增加，我们测量了液态金硅（AuSi）催化剂颗粒中固态硅（Si）的成核和生长动力学，这是纳米线气液固生长的第一步。定量测量结果与动力学模型吻合良好，为生长过程提供了统一的图景。成核是异质的，始终发生在AuSi液滴的边缘，但它是内在的且具有高度可重复性。我们研究了成核所需的临界过饱和度，发现即使对于直径低至12纳米的系统，也没有观察到尺寸效应。对于纳米技术应用而言，可重复性至关重要，异质性有助于更好地控制成核，而不存在强烈的尺寸效应则简化了工艺设计。
