Parallel conduction in GaAs/Al_xGa_1-xAs modulation doped heterojunctions

Abstract

Presents the results of a study of the electrical properties of a GaAs/AlxGa1-xAs modulation doped heterostructure where there are parallel competing conduction paths in the 2D gas at the GaAs/AlxGa1-xAs interface and in the undepleted AlxGa1-xAs. The authors show that the presence of these two paths introduces a magnetic field dependence into the measured resistivity and Hall coefficient of the heterostructure. This magnetic field dependence is analysed in order to determine the carrier densities and mobilities in the separate layers. This analysis is then used to investigate the effects of illumination on the heterojunction and to explain partially the temperature dependence of the properties of the heterojunction.