IFW Dresden, Institute of Complex Materials, P.O. Box 270116, D-01171 Dresden, Germany.
Nano Lett. 2014 Jun 11;14(6):3064-71. doi: 10.1021/nl501039c. Epub 2014 May 6.
We propose a detailed mechanism for the growth of vertical graphene by plasma-enhanced vapor deposition. Different steps during growth including nucleation, growth, and completion of the free-standing two-dimensional structures are characterized and analyzed by transmission electron microscopy. The nucleation of vertical graphene growth is either from the buffer layer or from the surface of carbon onions. A continuum model based on the surface diffusion and moving boundary (mass flow) is developed to describe the intermediate states of the steps and the edges of graphene. The experimentally observed convergence tendency of the steps near the top edge can be explained by this model. We also observed the closure of the top edges that can possibly stop the growth. This two-dimensional vertical growth follows a self-nucleated, step-flow mode, explained for the first time.
我们提出了一种通过等离子体增强气相沉积生长垂直石墨烯的详细机制。通过透射电子显微镜对生长过程中的不同步骤（包括成核、生长和独立二维结构的完成）进行了表征和分析。垂直石墨烯生长的成核可以来自缓冲层，也可以来自碳洋葱的表面。我们建立了一个基于表面扩散和移动边界（质量流）的连续模型，以描述台阶和石墨烯边缘的中间状态。通过该模型可以解释实验中观察到的顶部边缘附近台阶收敛的趋势。我们还观察到了顶部边缘的闭合，这可能会阻止生长。这种二维垂直生长遵循自成核的台阶流模式，这是首次解释。
