Uniform hexagonal graphene flakes and films grown on liquid copper surface

Proc Natl Acad Sci U S A. 2012 May 22;109(21):7992-6. doi: 10.1073/pnas.1200339109. Epub 2012 Apr 16.

Abstract

Unresolved problems associated with the production of graphene materials include the need for greater control over layer number, crystallinity, size, edge structure and spatial orientation, and a better understanding of the underlying mechanisms. Here we report a chemical vapor deposition approach that allows the direct synthesis of uniform single-layered, large-size (up to 10,000 μm(2)), spatially self-aligned, and single-crystalline hexagonal graphene flakes (HGFs) and their continuous films on liquid Cu surfaces. Employing a liquid Cu surface completely eliminates the grain boundaries in solid polycrystalline Cu, resulting in a uniform nucleation distribution and low graphene nucleation density, but also enables self-assembly of HGFs into compact and ordered structures. These HGFs show an average two-dimensional resistivity of 609 ± 200 Ω and saturation current density of 0.96 ± 0.15 mA/μm, demonstrating their good conductivity and capability for carrying high current density.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Copper / chemistry*
  • Crystallization / methods*
  • Electronics / methods*
  • Graphite / chemistry*
  • Materials Testing
  • Nanostructures / chemistry
  • Nanotechnology / methods*
  • Particle Size
  • Quartz / chemistry
  • Surface Properties

Substances

  • Quartz
  • Graphite
  • Copper