Scaling of semiconductor devices has reached a stage where it has become absolutely imperative to consider the quantum mechanical aspects of transport in these ultra small devices. In these simulations, often one excludes a rigorous band structure treatment, since it poses a huge computational challenge. We have proposed here an efficient method for calculating full three-dimensionally coupled quantum transport in nanowire transistors including full band structure. We have shown the power of the method by simulating hole transport in p-type Ge nanowire transistors. The hole band structure obtained from our nearest neighbor sp3s* tight binding Hamiltonian agrees well qualitatively with more complex and accurate calculations that take third nearest neighbors into account. The calculated I-V results show how shifting of the energy bands due to confinement can be accurately captured only in a full band full quantum simulation.
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