Quantum and Semi-Classical Transport in NEMO 1-D

The coupling of the fundamentally quantum mechanical nanoelectronic transport simulation through resonant tunneling diodes to semi-classical drift diffusion in the contacts is demonstrated. The coupling between the non-equilibrium Green function formalism used in NEMO to the drift diffusion equation is established by the use of spatially dependent quasi Fermi levels in the reservoirs. The charge distributions are computed quantum mechanically throughout the whole device using the full bandstructure sp3s* tight binding model that includes band non-parabolicity and band warping. The formalism is applied to the simulation of high current density resonant tunneling diodes. Low mobility contacts are shown to introduce a bi-stability in the negative differential resistance region.