Self organization of a hexagonal network of quasi-free-standing monolayer graphene nanoribbons

We investigated the H desorption process and the surface structure after H desorption in quasi-free-standing monolayer graphene (QFMLG) on silicon carbide (SiC). In situ scanning tunneling microscopy observations revealed that H adatoms preferentially desorb at SiC step edges. We found self-organization of a hexagonal network of QFMLG nanoribbons during H desorption. The surface structure on the nanoribbons indicates that electron scattering occurs at the boundary between the QFMLG and H-desorbed regions. The configuration of the network is determined by the formation energy of the boundary and by the surface stress energy. DOI: 10.1103/PhysRevB.87.165408