Regensburg 2022 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 72: 2D Materials 3: hBN and Electronic Structure

O 72.8: Vortrag

Donnerstag, 8. September 2022, 16:45–17:00, S052

Threshold Energies for Defect Production in 2D Materials under Low Energy Ion bombardment: Insights from ab-initio Molecular Dynamics — •Silvan Kretschmer, Sadegh Ghaderzadeh, Stefan Facsko, and Arkady V. Krasheninnikov — Helmholtz-Zentrum Dresden-Rossendorf, Germany

Low energy ion implantation (LEII) provides a valuable tool to tune the mechanical, electronic and catalytic properties of 2D materials by the targeted implantation of impurities. In contrast to ion irradiation at higher energies the commonly applied binary collision formula fails to describe the outcome of the irradiation process for ions close to the displacement energy, that is the minimum ion energy needed to displace the target atom. The dominating influence of the chemical interaction of projectile and target atoms and its effect on the displacement energy are adressed in this work. For that, we carried out ab-initio molecular dynamics (MD) simulations for a broad range of projectiles (elements Hydrogen to Argon) impacting on graphene and h-BN, and determined the energies needed to displace C, N and B atoms, respectively. We further present and validate a scheme to incorporate the effect of spin-polarization on the displacement process - as spin-polarized ab-initio MD runs tend to fail at bond-breaking.