Physical Review B 53, 1502 (1996)

Formation times of electric field domains in doped GaAs-AlAs superlattices

J. Kastrup1, F. Prengel2, H. T. Grahn1, K. Ploog1, and E. Schöll2

1 Paul-Drude-Institut für Festkörperelektronik,
Hausvogteiplatz 5-7, 10117 Berlin, Germany

2 Institut für Theoretische Physik, Technische Universität Berlin,
Hardenbergstrasse 36, 10623 Berlin, Germany

Abstract

Electric field domains in doped semiconductor superlattices lead to a series of stable branches in the current-voltage characteristics. The formation time of the domains is interpreted as the equilibration time of the system after the bias voltage is applied. Time-resolved current measurement techniques in conjunction with simulations are used to analyze the domain formation. Two different formation mechanisms are found. The investigated sample exhibits formation times from a few hundred nanoseconds up to several microseconds, depending on the applied voltage. For more strongly coupled superlattices much shorter formation times are expected.

PACS numbers: 72.20.Ht, 73.40.Gk

last update: Sep 29, 1995