Resonant tunneling in electrically biased multibarrier systems

The effect of a uniform electric field on the resonant tunneling across multibarrier systems (GaAs/AlxGa1-xAs and GaN/AlxGa1-xN) is exhaustively explored by a computational model using exact Airy function formalism and the transfer-matrix technique. The numerical computation takes care of the common problems of numerical inefficiency and overflow associated with the Airy functions for low-applied voltages. The model presents the study of both the field-free and field-dependent tunneling across multibarrier systems using a single formalism. The current-voltage characteristics, studied for the multibarrier systems with different number of barriers, exhibit all the experimentally observed features like resonant peaks, negative differential conductivity regimes, etc. Our results have both qualitative and quantitative agreement with the reported experimental findings. (C) 2008 Elsevier B.V. All rights reserved.