We show with angle-resolved photoemission spectroscopy that a new energy band appears in the electronic structure of electron-doped hydrogenated monolayer graphene (H-graphene). 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 pi* resonance.
Direct observation of a dispersionless impurity band in hydrogenated graphene / Haberer, D., Petaccia, L., Farjam, M., Taioli, S., Jafari, S.a., Nefedov, A., Zhang, W., Calliari, L., Scarduelli, G., Dora, B., Vyalikh, D.v., Pichler, T., Woll, C., Alfe, D., Simonucci, S., Dresselhaus, M.s., Knupfer, M., Buchner, B., Gruneis, A.. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - 83:16(2011). [10.1103/PhysRevB.83.165433]
Direct observation of a dispersionless impurity band in hydrogenated graphene
Alfe D;
2011
Abstract
We show with angle-resolved photoemission spectroscopy that a new energy band appears in the electronic structure of electron-doped hydrogenated monolayer graphene (H-graphene). 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 pi* resonance.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
