Thermalization of photoexcited carriers in bismuth investigated by time-resolved terahertz spectroscopy and ab initio calculations

I. Timrov (1) , T. Kampfrath (2, 3) , Jérôme Faure (1) , N. Vast (1) , C.R. Ast (4) , C. Frischkorn (2, 3) , M. Wolf (2, 3) , P. Gava (1) , L. Perfetti (2, 1)

1 LSI - Laboratoire des Solides Irradiés
2 Fachbereich Physik [Freie Univeristät Berlin] | Department of Physics [Freie Univeristät Berlin]
3 FHI - Fritz-Haber-Institut der Max-Planck-Gesellschaft
4 Max-Planck-Institut für Festkörperforschung

The charge carrier dynamics of photoexcited bismuth generates a Drude response that evolves over time. Our data show that the plasma frequency of bismuth displays an initial increase and a subsequent decay. We have performed ab initio calculations on bulk bismuth within the density functional theory and show that this peculiar behavior is due to local extrema in the valence and conduction bands. It follows that most of the carriers first accumulate in these extrema and reach the Fermi level only 0.6 ps after the photoexcitation. © 2012 American Physical Society.

I. Timrov, T. Kampfrath, Jérôme Faure, N. Vast, C.R. Ast, et al.. Thermalization of photoexcited carriers in bismuth investigated by time-resolved terahertz spectroscopy and ab initio calculations. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2012, 85 (15), pp.NA. ⟨10.1103/PhysRevB.85.155139⟩. ⟨hal-00739056⟩