• 文献标题:   Epitaxial Graphene Growth and Shape Dynamics on Copper: Phase-Field Modeling and Experiments
  • 文献类型:   Article
  • 作  者:   MECA E, LOWENGRUB J, KIM H, MATTEVI C, SHENOY VB
  • 作者关键词:   graphene, phase field modeling, epitaxial growth, anisotropic diffusion
  • 出版物名称:   NANO LETTERS
  • ISSN:   1530-6984 EI 1530-6992
  • 通讯作者地址:   Univ Penn
  • 被引频次:   81
  • DOI:   10.1021/nl4033928
  • 出版年:   2013

▎ 摘  要

The epitaxial growth of graphene on copper foils is a complex process, influenced by thermodynamic, kinetic, and growth parameters, often leading to diverse island shapes including dendrites, squares, stars, hexagons, butterflies, and lobes. Here, we introduce a phase-field model that provides a unified description of these diverse growth morphologies and compare the model results with new experiments. Our model explicitly accounts for the anisotropies in the energies of growing graphene edges, kinetics of attachment of carbon at the edges, and the crystallinity of the underlying copper substrate (through anisotropy in surface diffusion). We show that anisotropic diffusion has a very important, counterintuitive role in the determination of the shape of islands, and we present a "phase diagram" of growth shapes as a function of growth rate for different copper facets. Our results are shown to be in excellent agreement with growth shapes observed for high symmetry facets such as (111) and (001) as well as for high-index surfaces such as (221) and (310).