Electronic transport properties of epitaxial graphene buffer layer on Silicon Carbide

The confinement control sublimation is used to produce high quality epitaxial graphene on SiC for nanoelectronics. We report here on the experimental investigation of the first graphene layer grown on SiC(0001) (the buffer layer). The buffer layer is a semiconducting form of graphene, with a gap in the density of state previously probed by ARPES and STM measurements. We characterize our samples by Raman spectroscopy, photoemission spectroscopy, and atomic and lateral force microscopy to confirm their structural properties and produce electronic devices on single SiC terraces. The temperature and electric field dependence of the bulk conductivity of the buffer layer are investigated and the effects of contacts and gas adsorption are considered. The observed behavior seem to be related to the known structural periodicity of the buffer layer.