Anomalous real space charge transfer through thick barriers in GaAsAlxGa1−xAs asymmetric double quantum wells: AlxGa1−xAs as a percolating barrier

Anomalously large real space charge transfer through thick barriers in GaAs asymmetric double quantum wells is studied. This inter-well excitonic transfer is very large when the barrier is the Al0.3Ga0.7As alloy, but disappears when the barrier is an equivalent GaAs/AlAs digital alloy. These results combined with observed x and barrier thickness dependence suggest that the inhomogeneities in the barrier may be responsible for this transfer. This picture is supported by the quantum mechanical calculation in three dimensions. Copyright (C) 1996 Published by Elsevier Science Ltd