Electron-electron interactions in device simulation via nonequilibrium Green's functions and the GW approximation


METADATA ONLY
Loading...

Date

2025-05-15

Publication Type

Journal Article

ETH Bibliography

yes

Citations

Altmetric
METADATA ONLY

Data

Rights / License

Abstract

The continuous scaling of metal-oxide-semiconductor field-effect transistors (MOSFETs) has led to device geometries where charged carriers are increasingly confined to ever smaller channel cross sections. This development is associated with reduced screening of long-range Coulomb interactions. To accurately predict the behavior of such ultra-scaled devices, electron-electron (e-e) interactions must be explicitly incorporated in their quantum transport simulation. In this paper, we present an ab initio atomistic simulation framework based on density functional theory, the nonequilibrium Green's function formalism, and the self-consistent GW approximation to perform this task. The implementation of the method and its approximations are first tested with a carbon nanotube structure before being applied to calculate the transfer characteristics of a silicon nanowire MOSFET in a gate-all-around configuration. As a consequence of e-e scattering, the energy and spatial distribution of the carrier and the spectral current density both significantly change, while the on-current of the transistor decreases owing to the Coulomb repulsion between the electrons. Furthermore, we demonstrate how the resulting bandgap modulation of the nanowire channel as a function of the gate-to-source voltage could potentially improve device performance. This study reports large-scale atomistic quantum transport simulations of nanodevices under nonequilibrium conditions and in the presence of e-e interactions within the GW approximation.

Publication status

published

Editor

Book title

Volume

111 (19)

Pages / Article No.

195421

Publisher

American Physical Society

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

Organisational unit

Notes

Funding

209358 - Quantum Transport Simulations at the Exascale and Beyond (QuaTrEx) (SNF)
885893 - Investigation of carrier multiplication in van der Waals heterostructures for highly efficient solar cells (EC)

Related publications and datasets

Is supplemented by: