Theory of high-field electron transport in the heterostructures AlxGa1-xAs/GaAs/AlxGa1-x with delta-doped barriers. Effect of real-space transfer

Abstract

Steady-state electric characteristics of quantum heterostructures AlxGa1–xAs/GaAs/AlxGa1–xAs with  -doped barriers have been analyzed in this work. It has been shown that at high doping the additional low-conductive channels are formed in the barrier layers. Current-voltage characteristics of the structure were obtained in the wide interval of applied electric fields up to several kV/cm being based on the solution of Boltzmann transport equation. It has been found that in the electric fields higher than 1 kV/cm the effect of exchange of the carriers between the high-conductive channel of the GaAs quantum well and the channels in the AlGaAs barriers becomes essential. This effect gives rise to the appearance of the strongly nonlinear current-voltage characteristics with a portion of negative differential conductivity. The developed model of heterostructure is adequate to those recently fabricated and studied by Prof. Sarbey’s group. The obtained results explain some observation of this paper. It has been found that the effect of electron real-space transfer takes place at both low temperatures and room temperatures, which opens perspectives to design novel type nanostructured current controlled devices.