Trapping surface electrons on graphene layers and islands

Article

关键词: METAL-SURFACES;    WORK FUNCTION;    PHOTOELECTRON-SPECTROSCOPY;    2-PHOTON PHOTOEMISSION;    IMAGE STATES;    SCATTERING;    EMISSION;    PHASE;    BANDS;   

DOI  :  10.1103/PhysRevB.85.081402

来源: SCIE

【 摘 要 】

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 midgap clean metal surfaces. Evidence of localization of the excited electrons on single-atom-layer graphene islands is provided by coverage-dependent measurements.

【 授权许可】

Free