Tuning Charge Transport in Aromatic-Ring Single-Molecule Junctions via Ionic-Liquid Gating

Angew Chem Int Ed Engl. 2018 Oct 22;57(43):14026-14031. doi: 10.1002/anie.201807465. Epub 2018 Oct 4.

Abstract

Achieving gate control with atomic precision, which is crucial to the transistor performance on the smallest scale, remains a challenge. Herein we report a new class of aromatic-ring molecular nanotransistors based on graphene-molecule-graphene single-molecule junctions by using an ionic-liquid gate. Experimental phenomena and theoretical calculations confirm that this ionic-liquid gate can effectively modulate the alignment between molecular frontier orbitals and the Fermi energy level of graphene electrodes, thus tuning the charge-transport properties of the junctions. In addition, with a small gate voltage (|VG |≤1.5 V) ambipolar charge transport in electrochemically inactive molecular systems (EG >3.5 eV) is realized. These results offer a useful way to build high-performance single-molecule transistors, thus promoting the prospects for molecularly engineered electronic devices.

Keywords: aromatic rings; charge transport; graphene; ionic liquids; single-molecule junction.