Work

Epitaxial Graphene Growth and Shape Dynamics on Copper: Phase-Field Modeling and Experiments

Year: 2013

Type: article

Abstract: 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).

Source: Nano Letters

DOI: 10.1021/nl4033928

Authors: Esteban Meca, John Lowengrub, Hokwon Kim, Cecilia Mattevi, Vivek B. Shenoy

Institutions: University of California, Irvine, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Laboratoire d'Électronique des Technologies de l'Information, Imperial College London, University of Pennsylvania

Language: English

Topic: Graphene research and applications

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funder: Engineering and Physical Sciences Research Council

Award: EPSRC-Royal Society fellowship engagement (2012): Tailoring the Electronic Properties of Semiconducting Transition Metal Dichalcogenides