Switching and Rectification of a Single Light-sensitive Diarylethene Molecule Sandwiched between Graphene Nanoribbons

TL;DR

This study demonstrates that a diarylethene molecule sandwiched between graphene nanoribbons exhibits significant switching and rectification behavior, with potential applications in molecular electronics.

Contribution

It reveals the rectification effect in a single diarylethene molecule between graphene nanoribbons, highlighting the role of GNR band gap and molecular orbital variation.

Findings

High rectification ratio (>10^3) observed with mixed GNR types.

Switching between 'open' and 'closed' isomers drastically changes current-voltage characteristics.

Rectification is due to GNR band gap and bias-dependent LUMO variation.

Abstract

The 'open' and 'closed' isomers of the diarylethene molecule that can be converted between each other upon photo-excitation are found to have drastically different current-voltage characteristics when sandwiched between two graphene nanoribbons (GNRs). More importantly, when one GNR is metallic and another one is semiconducting, strong rectification behavior of the 'closed' diarylethene isomer with the rectification ratio >10^3 is observed. The surprisingly high rectification ratio originates from the band gap of GNR and the bias-dependent variation of the lowest unoccupied molecular orbital (LUMO) of the diarylethene molecule, the combination of which completely shuts off the current at positive biases. Results presented in this paper may form the basis for a new class of molecular electronic devices.