Modulating transmission properties of nanoscale transistors by dipole effects near contacts

TL;DR

This paper theoretically shows how a dipole layer on electrodes can control nanoscale transistor transmission by altering contact electrostatics, using first principles simulations of potassium-adsorbed gold contacts.

Contribution

It introduces a method to modulate contact properties in nanoscale transistors via dipole layers, expanding control beyond traditional gate voltages.

Findings

Dipole layers significantly shift electrostatic potential at contacts.

Parallel dipoles can supplement gate voltage effects.

Perpendicular dipoles modify contact interface barriers.

Abstract

We theoretically demonstrate that a dipole layer on the electrode can modulate the transmission properties of nanoscale devices by influencing the contact properties, through first principles simulations on carbon nanotube based field effect transistors. The dipole layer is realized by potassium adsorption on Au electrodes, which shifts the electrostatic potential at the near contact region significantly. The dipoles parallel to the direction of the bias voltage may act as a supplement to the effect of gate voltages, while the perpendicular dipoles may modify the interface barrier of the contacts.