Dresden 2026 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 26: Transport in Materials: Diffusion, Charge, or Heat Conduction I
MM 26.2: Talk
Wednesday, March 11, 2026, 16:00–16:15, SCH/A216
Multiscale modeling of cooperative defect dynamics in MoS2 — •Aaron Flötotto1,2, Erich Runge1,2, and Christian Dreßler1,2 — 1Technische Universität Ilmenau, Institut für Physik, Ilmenau, Germany — 2Technische Universität Ilmenau, Institut für Mikro- und Nanotechnologien, Ilmenau, Germany
Chalcogen vacancies strongly influence the electrical and memristive properties of transition metal dichalcogenides including MoS2. However, capturing their dynamics at device-relevant time and length scales is challenging due to the high energy barriers associated with individual atomic jumps [1]. We have developed a multiscale framework for MoS2 that uses ab-initio molecular dynamics to generate training data for machine-learning force fields. This step reveals the motifs of cooperative sulfur-vacancy migration and cluster formation [2]: (i) Vacancy migration almost exclusively occurs by vacancy-assisted hopping, implying non-linearities and suggesting memristive behavior; (ii) An energy barrier comparable to lab temperatures protects long vacancy lines against splitting into smaller vacancy clusters.
These insights are incorporated into a Monte-Carlo model that reproduces several key experimental observations and enables the prediction of device level quantities, such as the vacancy-density-dependence of the diffusion coefficient of sulfur vacancies in MoS2.
[1] Q. Chen, et al. , ACS Nano 12, 7721-7730 (2018), doi: 10.1021/acsnano.8b01610.
[2] A. Flötotto, et al., arXiv:2508.13790 (2025).
Keywords: Molecular-Dynamics; Transition-metal dichalcogenides; Crystal defects