Multipeak Negative Differential Resistance from Interplay between Nonlinear Stark Effect and Double-Branch Current Flow

TL;DR

This paper presents a first-principles design of molecular devices exhibiting multipeak negative differential resistance caused by nonlinear Stark effects and electron localization, enabling tailored electronic properties.

Contribution

It introduces a novel mechanism for multipeak NDR in molecular devices through interplay of Stark shifts and double-branch contacts, expanding the understanding of NDR phenomena.

Findings

Multipeak NDR observed in molecular devices with double-branch contacts.

Deep I(V) curves form at voltages where single-junction devices show flat steps.

Stark shifts at contacts and molecular regions cause oscillatory NDR behavior.

Abstract

Multipeak negative differential resistance (NDR) molecular devices are designed from first principles. The effect of NDR is associated with the non-linear Stark shifts and the electron localization within the conductive region and contacts. Deep I(V)-curve well is formed when the aromatic molecule, containing intramolecular hydrogen bond, is connected to each lead by the double-branch contacts. This effect occurs at the same voltage where a single-junction case exhibits only a flat step in the current characteristics. The multipeak oscillations arise from the mutual effect of the Stark shifts located at the electron-rich contacts and parts of the molecule - this opens the route for further tailoring the desired properties.