Pedro Brandimarte

Electronic Properties of Substitutionally Boron-Doped Graphene Nanoribbons on a Au(111) Surface

Journal of Physical Chemistry C - 2018    

Abstract

High-quality graphene nanoribbons (GNRs) grown by on-surface synthesis strategies with atomic precision can be controllably doped by inserting heteroatoms or chemical groups in the molecular precursors. Here, we study the electronic structure of armchair GNRs substitutionally doped with di-boron moieties at the center, through a combination of scanning tunneling spectroscopy, angle-resolved photoemission, and density functional theory simulations. Boron atoms appear with a small displacement toward the surface, signaling their stronger interactions with the metal. We find two boron-rich flat bands emerging as impurity states inside the GNR band gap, one of them particularly broadened after its hybridization with the gold surface states. In addition, the boron atoms shift the conduction and valence bands of the pristine GNR away from the gap edge and leave unaffected the bands above and below, which become the new frontier bands and have a negligible boron character. This is due to the selective mixing of boron states with GNR bands according to their symmetry. Our results depict that the GNR band structure can be tuned by modifying the separation between di-boron moieties.

Press release

Bibtex citation

@Article{Carbonell-Sanroma2018,
  author    = {Eduard Carbonell-Sanrom{\`{a}} and Aran Garcia-Lekue and Martina Corso and Guillaume Vasseur and Pedro Brandimarte and Jorge Lobo-Checa and Dimas G. de Oteyza and Jingcheng Li and Shigeki Kawai and Shohei Saito and Shigehiro Yamaguchi and J. Enrique Ortega and Daniel S{\'{a}}nchez-Portal and Jose Ignacio Pascual},
  title     = {Electronic Properties of Substitutionally Boron-Doped Graphene Nanoribbons on a Au(111) Surface},
  journal   = {Journal of Physical Chemistry C},
  year      = {2018},
  volume    = {122},
  number    = {28},
  pages     = {16092--16099},
  issn      = {1932--7447},
  doi       = {10.1021/acs.jpcc.8b03748},
  publisher = {American Chemical Society ({ACS})},
}

Key words

• graphene nanoribbons
• di-boron chemical substitution
• scanning tunneling spectroscopy
• angle-resolved photoemission
• electronic structure
• density functional theory