Anomalous Behavior of the Hall Effect in III-V Heterostructures

Thin, undoped heterostructures are very interesting from the point of view of their transport properties. In such samples the contribution of the conduction band or valence band carriers to the conductivity can be small and effects associated with the interface can become dominant. In our previous paper we showed that in a thin, undoped In0.53Ga0.47As/ΙnΡ heterostructure nearly all the electrical conduction takes place in the impurity band at the interface [1]. The electrical conduction in the impurity band was about 95% of the total electrical conduction. It was suggested there that the impurity band originated from unintentionally introduced impurities and interfacial dislocations. The effect of dislocations on the electrical conduction in GaAs-based compounds has been widely investigated [2-12]. However, skew scattering has not been taken into account. It is well known that at the interface there is a high density of dislocations and we can expect a significant influence of dislocation on the electrical conduction in the layer in which the interface conduction is dominant. In the analysis of the electrical conduction, dislocations have been considered as