Ion-Induced Surface Charge Dynamics in Freestanding Monolayers of Graphene and MoS₂ Probed by the Emission of Electrons

Author(s)

Anna Niggas, Janine Schwestka, Karsten Balzer, David Weichselbaum, Niclas Schlünzen, René Heller, Sascha Creutzburg, Heena Inani, Mukesh Tripathi, Carsten Speckmann, Niall McEvoy, Toma Susi, Jani Kotakoski, Ziyang Gan, Antony George, Andrey Turchanin, Michael Bonitz, Friedrich Aumayr, Richard A. Wilhelm

Abstract

We compare the ion-induced electron emission from freestanding monolayers of graphene and MoS2 to find a sixfold higher number of emitted electrons for graphene even though both materials have similar work functions. An effective single-band Hubbard model explains this finding by a charge-up in MoS2 that prevents low energy electrons from escaping the surface within a period of a few femtoseconds after ion impact. We support these results by measuring the electron energy distribution for correlated pairs of electrons and transmitted ions. The majority of emitted primary electrons have an energy below 10 eV and are therefore subject to the dynamic charge-up effects at surfaces.

Organisation(s)

Physics of Nanostructured Materials

External organisation(s)

Technische Universität Wien, Christian-Albrechts-Universität zu Kiel, Helmholtz-Zentrum Dresden-Rossendorf, University of Dublin, Friedrich-Schiller-Universität Jena

Journal

Physical Review Letters

Volume

129

No. of pages

9

ISSN

0031-9007

DOI

https://doi.org/10.1103/PhysRevLett.129.086802

Publication date

08-2022

Peer reviewed

Yes

Austrian Fields of Science 2012

103018 Materials physics, 103042 Electron microscopy

ASJC Scopus subject areas

Physics and Astronomy(all)

Portal url

https://ucris.univie.ac.at/portal/en/publications/ioninduced-surface-charge-dynamics-in-freestanding-monolayers-of-graphene-and-mos2-probed-by-the-emission-of-electrons(66860303-0179-4e89-a13d-ca4d4d314443).html