Dresden 2003 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 39: Ultrakurzzeitph
änomene I
HL 39.6: Vortrag
Donnerstag, 27. März 2003, 12:15–12:30, BEY/81
Femtosecond time resolved hole transport in GaAs — •A. Schwanhäußer1, M. Eckardt1, O. Schmidt1, S. Malzer1, G.H. Döhler1, M. Betz2, S. Trumm2, A. Leitenstorfer2, M. Hanson3, D. Driscoll3, and A.C. Gossard3 — 1Institut für technische Physik I, Universität Erlangen-Nürnberg, Erwin-Rommel-Str.1, 91058 Erlangen, Germany — 2Physik-Department E11, Technische Universität München, D-85748 Garching, Germany — 3Department of Electrical Engineering, University of California at Santa Barbara, Santa Barbara, California 93106
Transport properties of electrons in compound semiconductors have been of great interest for decades while holes had been neglected.
Namely the pronounced effect of the velocity overshoot, linked with the transfer of electrons into side valleys of the bandstructure has justified intense research. Experiments were carried out by [1], relying on the THz radiation emitted by the accelerated, combined electron-hole dipole of photogenerated carriers in a diode. A novel concept [2], combines a fs two color pump and probe laser source and a bandgap engineered pin AlGaAs heterostructure. This technique allows for unipolar transport studies, only probing the properties of electrons or holes. Besides of femtosecond time resolution also information of the transient spatial distribution function can be obtained. In this contribution the field dependent hole dynamics on timescales of few picoseconds and length scales of few 100nm is presented.
[1] A. Leitenstorfer, et. Al, Phys Rev. Lett. 82 (1999) 5140 [2] A. Schwanhäußer, M. Eckardt, M.Betz, et.al., Physica B 314 (2002), 273