Direct Visualization of the Charge Transfer in a Graphene/α-RuCl<sub>3</sub> Heterostructure via Angle-Resolved Photoemission Spectroscopy.

Rossi, Antonio; Johnson, Cameron; Balgley, Jesse; Thomas, John C; Francaviglia, Luca; Dettori, Riccardo; Schmid, Andreas K; Watanabe, Kenji et al. · Nano Lett · 2023

basic_science · Level V

Where this comes from

Abstract

We investigate the electronic properties of a graphene and α-ruthenium trichloride (α-RuCl<sub>3</sub>) heterostructure using a combination of experimental techniques. α-RuCl<sub>3</sub> is a Mott insulator and a Kitaev material. Its combination with graphene has gained increasing attention due to its potential applicability in novel optoelectronic devices. By using a combination of spatially resolved photoemission spectroscopy and low-energy electron microscopy, we are able to provide a direct visualization of the massive charge transfer from graphene to α-RuCl<sub>3</sub>, which can modify the electronic properties of both materials, leading to novel electronic phenomena at their interface. A measurement of the spatially resolved work function allows for a direct estimate of the interface dipole between graphene and α-RuCl<sub>3</sub>. Their strong coupling could lead to new ways of manipulating electronic properties of a two-dimensional heterojunction. Understanding the electronic properties of this structure is pivotal for designing next generation low-power optoelectronics devices.