Direct observation of a dispersionless impurity band in hydrogenated graphene

  • chair:

    Haberer, D. / Petaccia, L. / Farjam, M. / Taioli, S. / Jafari, S. / Nefedov, A. / Zhang, W. / Calliari, L. / Scarduelli, G. / Dora, B. / Vyalikh, D. / Pichler, T. / Wöll, C. / Alfé, D. / Simonucci, S. / Dresselhaus, M. / Knupfer, M. / Büchner, B. / Grüneis, A. (2011)
  • place:

    Phys. Rev. B 83 (2011), 165433

  • Date: 2011

  • Haberer, D. / Petaccia, L. / Farjam, M. / Taioli, S. / Jafari, S. / Nefedov, A. / Zhang, W. / Calliari, L. / Scarduelli, G. / Dora, B. / Vyalikh, D. / Pichler, T. / Wöll, C. / Alfé, D. / Simonucci, S. / Dresselhaus, M. / Knupfer, M. / Büchner, B. / Grüneis, A. (2011): „Direct observation of a dispersionless impurity band in hydrogenated graphene“. In: Phys. Rev. B 83 (2011), 165433

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.


 

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