Electron dynamics of the buffer layer and bilayer graphene on SiC

Alex J. Shearer, James E. Johns, Benjamin W. Caplins, David E. Suich, Mark C. Hersam, Charles B. Harris

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


Angle- and time-resolved two-photon photoemission (TPPE) was used to investigate electronic states in the buffer layer of 4H-SiC(0001). An image potential state (IPS) series was observed on this strongly surface-bound buffer layer, and dispersion measurements indicated free-electron-like behavior for all states in this series. These results were compared with TPPE taken on bilayer graphene, which also show the existence of a free-electron-like IPS series. Lifetimes for the n = 2, and n = 3 states were obtained from time-resolved TPPE; slightly increased lifetimes were observed in the bilayer graphene sample for the n = 2 the n = 3 states. Despite the large band gap of graphene at the center of the Brillouin zone, the lifetime results demonstrate that the graphene layers do not behave as a simple tunneling barrier, suggesting that the buffer layer and graphene overlayers play a direct role in the decay of IPS electrons.

Original languageEnglish
Article number231604
JournalApplied Physics Letters
Issue number23
Publication statusPublished - Jun 9 2014

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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