Electrically Driven Nonresonant Single Molecular Switches

Electrical switching of a single-molecule junction provides a practical module to perform sophisticated operations in electronic devices. However, designing an all-electrically-driven molecular switch is a great challenge. Here, we experimentally and theoretically investigated the charge transport characteristics of isoindigo (ISO)-molecules at the single-molecule level using the scanning tunneling microscope break junction technique. We find that the single-molecule junctions of ISO-molecules display bias voltage -driven switching characteristics. These switches are realtime, reversible, and nondestructive under low-bias voltages. Experimental results show that the mechanism of the switch is not the transition from nonresonant charge transport to resonant charge transport, but it is the shift of the frontier orbital energy levels of ISO-molecules and the change of the interfacial electronic coupling with bias voltage. Our results will advance the design of high-performance bias voltage-driven molecular switches.

Automated summary

In this study, the charge transport characteristics of ISO molecules at the single-molecule level were investigated experimentally and theoretically. It was found that ISO molecules exhibit bias voltage-driven switching characteristics in single-molecule junctions. The mechanism behind the switch was identified as the shift of the frontier orbital energy levels of ISO molecules and the change of the interfacial electronic coupling with bias voltage. These findings will contribute to the design of high-performance bias voltage-driven molecular switches.