Enhanced electron density in two Si delta-doped Al0.33Ga0.67As/GaAs heterojunctions

We have investigated the electronic properties of the delta-doped Al0.33Ga0 .67As/GaAs heterojunction such as the electron density. We have also examin ed the case where the delta- doping is placed in a thin AlxGa1-xAs quantum well embedded in the Al0.33Ga0.67As barrier. This is intended to reduce the DX centers effects. In this context, we have grown a series of silicon del ta-doped Al0.33Ga0.67As/GaAs heterostructures having various alloy composit ions in the AlxGa1-xAs quantum well (x(Al)(well)). Hall measurements were p erformed on these samples in the temperature range 4-300 K. A self-consiste nt analysis (Schrodinger and Poisson equations) is made on these silicon de lta-doping systems. Moreover, a comparison between the theoretical and expe rimental results shows an agreement between them. (C) 1999 Elsevier Science Ltd. All rights reserved.