An Efficient Method for Quantum Transport Calculations in Nanostructures using Full Band Structure

TL;DR

This paper introduces an efficient computational method for quantum transport in nanostructures that incorporates full band structure, enabling accurate simulations of ultra-small semiconductor devices like nanowire transistors.

Contribution

The paper presents a novel, efficient approach for full 3D quantum transport calculations including full band structure, demonstrated on p-type Ge nanowire transistors.

Findings

The method accurately captures energy band shifts due to quantum confinement.

Simulated I-V characteristics match qualitative expectations from complex models.

Full band effects are essential for precise quantum transport simulations.

Abstract

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.