Optically Triggered Control of the Charge Carrier Density in Chemically Functionalized Graphene Field Effect Transistors

Zian Tang; Antony George; Andreas Winter; David Kaiser; Christof Neumann; Thomas Weimann; Andrey Turchanin

doi:10.1002/chem.202000431

Optically Triggered Control of the Charge Carrier Density in Chemically Functionalized Graphene Field Effect Transistors

Chemistry. 2020 May 20;26(29):6473-6478. doi: 10.1002/chem.202000431. Epub 2020 Mar 27.

Authors

Zian Tang¹, Antony George¹, Andreas Winter¹, David Kaiser¹, Christof Neumann¹, Thomas Weimann², Andrey Turchanin^{1

3}

Affiliations

¹ Institute of Physical Chemistry, Friedrich Schiller University Jena, Lessingstraße 10, 07743, Jena, Germany.
² Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116, Braunschweig, Germany.
³ Jena Center for Soft Matter, Philosophenweg 7, 07743, Jena, Germany.

Abstract

Field effect transistors (FETs) based on 2D materials are of great interest for applications in ultrathin electronic and sensing devices. Here we demonstrate the possibility to add optical switchability to graphene FETs (GFET) by functionalizing the graphene channel with optically switchable azobenzene molecules. The azobenzene molecules were incorporated to the GFET channel by building a van der Waals heterostructure with a carbon nanomembrane (CNM), which is used as a molecular interposer to attach the azobenzene molecules. Under exposure with 365 nm and 455 nm light, azobenzene molecules transition between cis and trans molecular conformations, respectively, resulting in a switching of the molecular dipole moment. Thus, the effective electric field acting on the GFET channel is tuned by optical stimulation and the carrier density is modulated.

Keywords: 2D materials; chemical functionalization; field effect transistors; graphene; photoresponsive devices.