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

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. © 1996 The American Physical Society.