Aberration Corrected Microscopy of CVD Graphene and Spectroscopic Ellipsometry of Epitaxial Graphene and CVD Graphene for Comparison of the Dielectric Function

Abstract

Chemical Vapor Deposition (CVD) on metallic foils and the thermal decomposition of SiC have become two of the dominant fabrication methods of large area graphene due to their industrial scalability. The work will present STEM imaging of CVD graphene performed at 60 kV with atomic resolution achieved through aberration correction. Single-crystal areas are identified as well as defect structures. Spectrscopic Ellipsometry (SE) is used to extract the dielectric function (complex refractive index) of graphene from both growth methods. Epitaxial graphene on SiC sits on a buffer layer, the dielectric function of which is also measured with SE for comparison to the pure sp2-bonded graphene layers.