SKM 2023 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 5: Focus Session: Ion Beam Interaction with Surfaces and 2D Materials I

O 5.5: Vortrag

Montag, 27. März 2023, 12:00–12:15, GER 38

chemical etching of 2D materials — •Mitisha Jain, Silvan Kretschmer, and Arkady Krasheninnikov — Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany

Transmission electron microscopes are used for imaging 2D materials to the resolution of single atoms. On the other hand, the imaged material gets damaged (modified by the beam) quite easily. Hence, the information about the damage done by the beam are important for proper imaging. Different channels of damage construction such as knock-on, ionization (excitation), chemical etching (e.g. adatoms) have been determined. In this study, the knock-on threshold energies for graphene (C), h-BN (B and N) and MoS2 (S) materials in the presence of adsorbed adatoms (H, C, N, O) on the surface are calculated in the framework of spin-polarized density functional theory. From the preliminary results, we found that when an adatom is adsorbed, the threshold energies are reduced by 2-3 eV compared to pristine systems. Further, we consider the additional effect of electronic excitation on the threshold energies in combination with adsorbed adatoms. The displacement cross-section under the electron beam are assessed employing the McKinley-Feshbach formalism allowing to compare different channels of damage creation.