Ultrafast Phenomena in II-VI Semiconductors |
| H. Kalt, S. Wachter, D. Lüerssen and J. Hoffmann Institut für Angewandte Physik, Universität Karlsruhe, 76128 Karlsruhe, Germany |
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| We review studies on the coherent and incoherent exciton dynamics in ZnSe-based quantum wells. First, the exciton-exciton scattering parameter is determined from femtosecond four-wave mixing as a function of background exciton density generated by a prepulse. A linear increase in the excitonic homogeneous linewidth is found as a function of the background exciton density with significant different scattering parameters for the cases of interaction with coherent or incoherent excitons. Second, the thermalization dynamics of spectrally narrow hot-exciton distributions is investigated by time-resolved phonon sideband spectroscopy. Thermalization assisted by acoustic phonons occurs on a 100 ps timescale, which is in good agreement with model calculations in time dependent perturbation theory. |
| DOI: 10.12693/APhysPolA.94.139 PACS numbers: 78.47.+p, 42.50.Md, 71.35.-y |