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

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