Intercalation of H at the graphene/SiC(0001) interface: Structure and stability from first principles

摘要: Abstract We investigate the intercalation of hydrogen at graphene/SiC(0001) interface through atomistic models characterized by very low strains both in epitaxial graphene and SiC substrate. Adsorption H is always stable but shows energy variations larger than 1 eV between different locations interface. An model presenting a strong interaction with substrate, corresponding to experimental situation, that adsorption on average 0.75 eV less surface buffer layer. At variance, having much weaker graphene/SiC results hydrogenation energies are comparable two cases. The structural modifications occurring upon show partial conversion layer into quasi-free standing graphene, accompanied marked downward relaxation hydrogenated Si atom local steric repulsion latter overlying graphene.