Ultrafast carrier and phonon dynamics in Bi2Se3 crystals
arXiv:1010.4265 · doi:10.1063/1.3513826
Abstract
Ultrafast time-resolved differential reflectivity of Bi2Se3 crystals is studied using optical pump-probe spectroscopy. Three distinct relaxation processes are found to contribute to the initial transient reflectivity changes. The deduced relaxation timescale and the sign of the reflectivity change suggest that electron-phonon interactions and defect-induced charge trapping are the underlying mechanisms for the three processes. After the crystal is exposed to air, the relative strength of these processes is altered and becomes strongly dependent on the excitation photon energy.
8 pages, 4 figures, accepted for publication in Applied Physics Letters
References in corpus (3)
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- Gate-Voltage Control of Chemical Potential and Weak Anti-localization in Bismuth Selenide
- Strong surface scattering in ultrahigh mobility Bi2Se3 topological insulator crystals