ABSTRACT
We present calculations of quantum transport of electrons in resonant tunneling diodes (RTDs) based on the non-equilibrium Green function theory where an evanescent-wave matching at heterointerfaces as well as the Γ-X valley-mixing effects, in addition, space charge effect are duly taken into account. Our results show, in particular, that current-voltage characteristics of a GaAs/AlAs double-barrier RTD have larger current densities than the conventional single band model since the latter model overestimates the decay constant in the barriers which is accurately treated in our present model. It should be also pointed out that the matching of evanescent electron modes is essentially necessary to include the valley-mixing effects for GaAs/AlAs heterostructures, since breaking of a lattice-translational symmetry occurs at the interfaces.
