Three-terminal devices to examine single molecule conductance switching

TL;DR

This study investigates conductance switching in single-molecule transistors using BPDN-DT molecules, finding rare gate dependence and suggesting mechanisms other than polaron formation.

Contribution

It provides the first electronic transport measurements of BPDN-DT in single-molecule transistors and analyzes the switching mechanisms involved.

Findings

Hysteretic conductance switching observed in 8% of devices

Gate voltage dependence of switching is rare

Polaron formation unlikely as the switching mechanism

Abstract

We report electronic transport measurements of single-molecule transistor devices incorporating bipyridyl-dinitro oligophenylene-ethynylene dithiol (BPDN-DT), a molecule known to exhibit conductance switching in other measurement configurations. We observe hysteretic conductance switching in 8% of devices with measurable currents, and find that dependence of the switching properties on gate voltage is rare when compared to other single-molecule transistor devices. This suggests that polaron formation is unlikely to be responsible for switching in these devices. We discuss this and alternative switching mechanisms.