Graphene refers to a two-dimensional crystal made of carbon atoms arranged on a honeycomb lattice. This material presents interesting electronic properties regarding fundamental physics as well as industrial applications, such as an exotic low-energy band structure and high charge carrier mobility. Its fabrication through the graphitization of SiC is a promising method for electronics. We studied this system using scanning tunnelling microscopy (STM) and ab initio numerical simulations with the aim of characterizing the graphene - SiC(000-1)  (carbon face) interface and studying the impact of the substrate on graphene’s electronic structure.

Experimental results are obtained on lightly graphitized samples fabricated in situ under ultra-high vacuum. They show two interface structures, the native SiC(000-1) surface reconstructions named (2x2)C and (3x3), on top of which lie graphene monolayer islands with a high rotational disorder leading to various moiré patterns on STM images. Using STM, I will show that the graphene/(3x3) interaction is very weak. I will then consider the stronger graphene/(2x2) interaction successively from the point of view of the graphene and the reconstruction states, in the direct and reciprocal space, using both our experimental and theoretical methods. Finally, I will address the impact of interfacial defects observed by STM through graphene/(2x2) islands and modelled with hydrogen adatoms on the electronic band structure and doping of graphene.