Carrier lifetime in exfoliated few-layer graphene determined from intersubband optical transitions

T. Limmer, J. Feldmann, E. Da Como

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

We report a femtosecond transient spectroscopy study in the near to middle infrared range, 0.8-0.35 eV photon energy, on graphene and few layer graphene single flakes. The spectra show an evolving structure of photoinduced absorption bands superimposed on the bleaching caused by Pauli blocking of the interband optically coupled states. Supported by tight-binding model calculations, we assign the photoinduced absorption features to intersubband transitions as the number of layers is increased. Interestingly, the intersubband photoinduced resonances show a longer dynamics than the interband bleaching, because of their independence from the absolute energy of the carriers with respect to the Dirac point. The dynamic of these intersubband transitions reflects the lifetime of the hot carriers and provides an elegant method to access it in this important class of semimetals.
LanguageEnglish
Article number217406
Number of pages5
JournalPhysical Review Letters
Volume110
Issue number21
Early online date23 May 2013
DOIs
StatusPublished - 24 May 2013

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bleaching
carrier lifetime
optical transition
graphene
metalloids
flakes
absorption spectra
life (durability)
energy
photons
spectroscopy

Cite this

Carrier lifetime in exfoliated few-layer graphene determined from intersubband optical transitions. / Limmer, T.; Feldmann, J.; Da Como, E.

In: Physical Review Letters, Vol. 110, No. 21, 217406, 24.05.2013.

Research output: Contribution to journalArticle

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