Schottky barrier inhomogeneities at the interface of few layer epitaxial graphene and silicon carbide

In this work, we study electron transport across the heterojunction interface of epitaxial few-layer graphene grown on silicon carbide and the underlying substrate. The observed Schottky barrier is characterized using current-voltage, capacitance-voltage and photocurrent spectroscopy techniques. It is found that the graphene/SiC heterojunction cannot be characterized by a single unique barrier height because of lateral barrier inhomogeneities. A Gaussian distribution of barrier heights with a mean barrier height phi(Bm) - 1.06 eV and standard deviation sigma - 137 +/- 11 meV explains the experimental data quite well. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4711769]