ACTA

Dynamics of the Electric Field in a GaAs/AlGaAs Superlattice after Femtosecond Optical Excitation: Application of Time-Resolved Spectroscopic Techniques

A. Lisauskas^a, C. Blöser^a, R. Sachs^a, H.G. Roskos^a, A. Juozapavičius^b, G. Valušis^a,b, and K. Köhler^c
^aPhysikalisches Institut, J.W. Goethe-Universität, Frankfurt/Main 60054, Germany
^bSemiconductor Physics Institute, Vilnius 01108, Lithuania
^cFraunhofer-Institut für Angewandte Festkörperphysik, Freiburg 79108, Germany

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Received: 22 08 2004;

We apply time-resolved photocurrent and differential electroreflectance spectroscopy to study the evolution of the internal field in a GaAs/AlGaAs superlattice after pulsed optical excitation at low temperature. The electric field dynamics is investigated by tracing the spectral position of the Wannier-Stark transitions as a function of delay time. We determine the electron sweep-out time, extract detailed information about the picosecond-time-scale drift of the charge carriers by comparing the measured data with the results of semi-classical self-consistent model calculations, and evaluate the two experimental techniques with respect to their ability to provide information about the carrier and field dynamics.

DOI: 10.12693/APhysPolA.107.250
PACS numbers:03.65.Sq, 78.47.+p