Graphene modification via cobalt and silicon intercalation

Abstract

Cobalt and silicon intercalation under graphene formed on the Co(111) surface has been investigated. The thickness of deposited films was varied within the range of up to 2 nm and the temperature of their annealing was 400-450°C. The evolution of atomic and electronic structure of the surface due to intercalation was studied by low-energy electron diffraction and high-resolution photoelectron spectroscopy with synchrotron radiation. It is shown that annealing of deposited Si layer leads to formation on the sample surface of both intercalated and nonintercalated areas. On the intercalated areas, the Co-Si solid solution is formed covered with segregated Si. The presence of a silicon phase strongly affects the electronic structure of graphene and substantially weakens its interaction with the substrate. Subsequent intercallation of Co leads to the restoration of strong coupling between graphene and the substrate.