Showing 1–1 of 1 results for author: Yeh, P -

Trapping Surface Electrons on Graphene Layers and Islands

Authors: D. Niesner, Th. Fauster, J. I. Dadap, N. Zaki, K. R. Knox, P. -C. Yeh, R. Bhandari, R. M. Osgood, M. Petrović, M. Kralj

Abstract: We report the use of time- and angle-resolved two-photon photoemission to map the bound, unoccupied electronic structure of the weakly coupled graphene/Ir(111) system. The energy, dispersion, and lifetime of the lowest three image-potential states are measured. In addition, the weak interaction between Ir and graphene permits observation of resonant transitions from an unquenched Shockley-type sur… ▽ More We report the use of time- and angle-resolved two-photon photoemission to map the bound, unoccupied electronic structure of the weakly coupled graphene/Ir(111) system. The energy, dispersion, and lifetime of the lowest three image-potential states are measured. In addition, the weak interaction between Ir and graphene permits observation of resonant transitions from an unquenched Shockley-type surface state of the Ir substrate to graphene/Ir image-potential states. The image-potential-state lifetimes are comparable to those of mid-gap clean metal surfaces. Evidence of localization of the excited electrons on single-atom-layer graphene islands is provided by coverage-dependent measurements. △ Less

Submitted 29 December, 2011; v1 submitted 9 September, 2011; originally announced September 2011.

Journal ref: Phys. Rev. B 85, 081402(R) (2012)