First-principles study on electron field emission from nanostructures

TL;DR

This paper introduces a first-principles computational method combining Green's functions and density functional theory to accurately simulate electron field emission from nanostructures, capturing experimental behaviors like current saturation.

Contribution

It presents a novel first-principles approach that accounts for emitted current in electron field emission simulations of nanostructures.

Findings

Reproduces experimental current saturation behavior

Captures deviation from Fowler-Nordheim law

Accurately models electron density in vacuum region

Abstract

A first-principles approach is introduced to calculate electron field emission characteristics of nanostructures, based on the nonequilibrium Green function technique combined with the density functional theory. The method employs atomic-like basis orbitals with large confinement radii and lithium anode to describe the electron density in the vacuum between the nanostructure tip and the anode, so takes the presence of emitted current into account. The simulation results on a capped single-walled carbon nanotube reproduce the experimental trend closely, in particular, the current saturation and the deviation from the Fowler-Nordheim behavior.