Carrier transport in an InGaAs(P)/InP all-optical switching structure

We presented a specially designed SCMQW structure, where hole transport is controlled by an additional large heterobarrier. This barrier gives access to steady state escape times by measuring the charge carrier induced field change in the MQW region. We get a minimum value for the hole extraction time over the barrier of several at 77 K. At a temperature of 200 K the measured time constants lie below the values, which our rate equation model and the semi-classical model predict, and show a stronger field dependence. This could be accounted for thermally assisted tunneling and contribution of light hole transport, which both reduce the effective barrier height and show a stronger field dependence. Further investigations of the transport times are currently in progress by changing the thickness of the InP barrier and the barrier height of the quaternary material.