Quasi‐Freestanding Graphene via Sulfur Intercalation: Evidence for a Transition State

Abstract Sulfur intercalation of a carbon rich (63×63)R30∘ reconstruction on silicon carbide, also known as buffer layer, is reported. In a two‐zone furnace a sulfur rich precursor is heated and the gaseous species is transported for intercalation by an argon flow to the sample. Successful intercalation can be confirmed by X‐ray photoelectron spectroscopy and low‐energy electron diffraction. Angle‐resolved photoelectron spectroscopy reveals a p‐type doping of the intercalated samples. In some cases only partial intercalation appears with non‐intercalated sulfur on top of the remaining buffer layer areas. Further annealing of such samples leads to a migration of the non‐intercalated sulfur under the buffer layer areas, indicating that the sulfur bonded to the buffer layer constitutes a transition state.