Selective formation of ABC-stacked graphene layers on SiC(0001)

An investigation using high-resolution transmission electron microscopy of the stacking sequence of several layers of graphene formed on SiC (0001) shows that graphene layers selectively exhibit an ABC-type stacking. Using the well-known Slonczewski-Weiss-McClure model based on the tight-binding method, we suggest that a gamma(5)-like interatomic interaction, which corresponds to the formation of a linear trimer of ABA type stacking, is spontaneously weakened by the interaction between graphene and SiC. This can lead to the destabilization of the ABA stacking and to the formation of the ABC stacking, indicating the possibility of bandgap tuning by an electric field in more than three layers of graphene on SiC.