First Principles Calculation of Field Emission from Nanostructures using Time-Dependent Density Functional Theory: a Simplified Approach

TL;DR

This paper presents a simplified ab-initio method using Time-Dependent Density Functional Theory to calculate electron field emission from nanostructures, specifically short carbon nanotubes, highlighting emission characteristics and potential applications.

Contribution

Introduces a new simplified computational approach for electron emission in nanostructures using TDDFT with the Crank-Nicholson propagator.

Findings

Emitted charge mainly originates from electrons at the nanotube tip.

Charge beam forms specific channel structures.

Method effectively captures emission behavior in pristine nanotubes.

Abstract

We introduce a new simplified method for computing the electron field emission current in short carbon nanotubes using ab-initio computation in periodic simulation cells. We computed the evolution of the wave functions using Time-Dependent Density Functional Theory, where we have utilized the Crank-Nicholson propagator. We found that in pristine carbon nanotubes, the emitted charge tends to emerge mostly from electrons that are concentrated at the nanotube tip region. The charge beam concentrates into specific channel structures, showing the utility of carbon nanotubes in precision emission applications.