BaDElPh Highlights

We show with angle-resolved photoemission spectroscopy that a new dispersionless band appears in the electronic structure of hydrogenated K-doped graphene (H-graphene) which is extended over the whole Brillouin zone. Its occupation can be controlled with the hydrogen amount and allows for tuning of graphene’s doping level. Our calculations of the electronic structure of H-graphene suggest that this state is largely composed of hydrogen 1s orbitals and remains extended for low H coverages despite the random chemisorption of H. Further evidence for the existence of a hydrogen state is provided by x-ray absorption studies of undoped H-graphene which are clearly showing the emergence of an additional state in the vicinity of the π* resonance. The spatial extension of H defects, their preferential adsorption patterns on graphene, and local electronic structure was also investigated by high-resolution scanning tunneling microscopy and spectroscopy.