Epitaxial graphene morphologies probed by weak (anti)-localization

Abstract

We show how the weak field magneto-conductance can be used as a tool to characterize epitaxial graphene samples grown from the C or the Si face of silicon carbide, with mobilities ranging from 120 to 12 000 cm2/(V·s). Depending on the growth conditions, we observe anti-localization and/or localization, which can be understood in term of weak-localization related to quantum interferences. The inferred characteristic diffusion lengths are in agreement with the scanning tunneling microscopy and the theoretical model which describe the “pure” mono-layer and bilayer of graphene [MacCann et al., Phys. Rev. Lett. 97, 146805 (2006)].