Direct View of Hot Carrier Dynamics in Graphene

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaperJournal articleResearchpeer-review

  • Jens Christian Johannsen, École Polytechnique Fédérale de Lausanne, Switzerland
  • Søren Ulstrup
  • Federico Cilento, Sinctrotrone Trieste, Italy
  • Alberto Crepaldi, Sincrotrone Trieste, Italy
  • Michele Zacchigna, IOM-CNR Laboratorio TASC, Italy
  • Cephise Cacho, STFC Rutherford Appleton Laboratory, United Kingdom
  • I.C.Edmond Turcu, STFC Rutherford Appleton Laboratory, United Kingdom
  • Emma Springate, STFC Rutherford Appleton Laboratory, United Kingdom
  • Felix Fromm, Technische Universität Chemnitz, Germany
  • Christian Raidel, Technische Universität Chemnitz, Germany
  • Thomas Seyller, Technische Universität Chemnitz, Germany
  • Fulvio Parmigiani, Sincrotrone Trieste & University of Trieste, Italy
  • Marco Grioni, École Polytechnique Fédérale de Lausanne, Switzerland
  • Philip Hofmann
The ultrafast dynamics of excited carriers in graphene is closely linked to the Dirac spectrum and plays
a central role for many electronic and optoelectronic applications. Harvesting energy from excited
electron-hole pairs, for instance, is only possible if these pairs can be separated before they lose energy
to vibrations, merely heating the lattice. Until now, the hot carrier dynamics in graphene could only be
accessed indirectly. Here, we present a dynamical view on the Dirac cone by time- and angle-resolved
photoemission spectroscopy. This allows us to show the quasi-instant thermalization of the electron gas to
a temperature of 2000 K, to determine the time-resolved carrier density, and to disentangle the subsequent
decay into excitations of optical phonons and acoustic phonons (directly and via supercollisions).
Original languageEnglish
JournalPhysical Review Letters
Pages (from-to)027403-1-027403-5
Number of pages5
Publication statusPublished - 9 Jul 2013

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