Growth of adlayers studied by fluorination of isotopically engineered graphene

Abstract

Chemical vapor deposition on copper is currently one of the most prospective preparation techniques of large area graphene films. There are still many undisclosed questions regarding the growth process and its conditions. The adlayer formation belongs to those, not only because of the need of uniform monolayers, but also due to the increasing demand for high-coverage bilayers. The combination of Raman spectroscopy, isotopic labeling and functionalization using fluorine can provide the necessary insight into the CVD growth process. The disorder degree caused by the fluorination is unambiguously distinguished by Raman mapping and evaluation of more than 1000 spectra for the individual layers, suggesting the shielding of the 13C adlayer underneath the continuous 12C top layer. High resolution Raman map of the D/G peak intensity ratio of the 12C component in the 13C/12C region of the studied isotopically labeled bilayer graphene and a scheme depicting the adlayer growth at the bottom.