Electroisomerization blinking of an azobenzene derivative molecule

TL;DR

This study demonstrates reversible and bistable electroisomerization of an azobenzene molecule induced by STM bias, resulting in a blinking effect observable in STM images at low temperature and ultra-high vacuum.

Contribution

It reveals the electric field-induced reversible switching behavior of azobenzene molecules at the single-molecule level using STM.

Findings

Reversible cis-trans switching observed at ±2V bias

Switching occurs on a sub-second timescale

Blinking effect visible in STM images

Abstract

We report here the reversibility and bistability of the switching behavior in an azobenzene derivative induced by the bias applied by a Scanning-Tunneling Microscopy (STM) tip, at low temperature and in ultra-high vacuum environment. This cis-to-trans and trans-to-cis switching were observed during STM imaging in either polarity at +2V or -2V, on a sub-second time scale. This results in a blinking effect visible on STM images, corresponding to the reversible switching of the azobenzene molecule under the applied STM bias through an electric field induced process.