Abstract
We present a study of graphene/substrate interactions on ultrahigh-vacuum-grown graphene islands with minimal surface contamination using in situ low-temperature scanning tunneling microscopy. We compare the physical and electronic structure of the sample surface with atomic spatial resolution on graphene islands versus regions of bare Cu(111) substrate. We find that the Rydberg-like series of image potential states is shifted toward lower energy over the graphene islands relative to Cu(111), indicating a decrease in the local work function, and the resonances have a much smaller linewidth, indicating reduced coupling to the bulk. In addition, we show the dispersion of the occupied Cu(111) Shockley surface state is influenced by the graphene layer, and both the band edge and effective mass are shifted relative to bare Cu(111).
Department
Physics
Publication Date
5-19-2015
Journal Title
Physical Review B
Publisher
American Physical Society
Digital Object Identifier (DOI)
10.1103/PhysRevB.91.195425
Document Type
Article
Recommended Citation
S. M. Hollen, G. A. Gambrel, S. J. Tjung, N. M. Santagata, E. Johnston-Halperin, and J. A. Gupta, ‘Modification of electronic surface states by graphene islands on cu(111)’, Physical Review B, vol. 91, no. 19, May 2015.
Rights
© 2015 American Physical Society