Optical detection of charge redistribution in a delta modulation-doped GaAs-AlxGa1-xAs heterojunction

We have investigated magnetically-induced charge redistribution within a delta modulation-doped GaAs-AlxGa1-xAs heterojunction structure by studying the photoluminescence due to electrons from the two-dimensional(2D) electron system recombining with photoexcited holes. At well defined values of magnetic field, charge transfer occurs between this 2D electron system and the V-shaped potential well formed in the AlxGa1-xAs by Si delta modulation-doping. This redistribution of charge is observed as discontinuities in the photoluminescence energies. From these measurements we have derived the characteristic transfer time for electrons to move between these two wells. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.109426727