Dresden 2026 – wissenschaftliches Programm

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

O: Fachverband Oberflächenphysik

O 34: Catalysis and surface reactions I

O 34.4: Vortrag

Dienstag, 10. März 2026, 11:15–11:30, HSZ/0204

Converting MoS₂ to MoO₂ by Thermal Treatment Under Dilute O₂ — •Armin Sahinovic¹, Jixi Zhang², Osamah Kharsah¹, Marika Schleberger¹, Rossitza Pentcheva¹, and Rodney Smith² — ¹Department of Physics and Center for Nanointegration, University of Duisburg-Essen, 47057 Duisburg, Germany — ²Department of Chemistry, University of Waterloo, ON N2L 3G1 Waterloo, Canada

The reaction of MoS₂ with O₂ at elevated temperatures introduces the risk of structural and functional degradation that decrease the lifespan of MoS₂-based devices [1]. In experiment, variable-temperature Raman measurements indicate that depending on the O₂ concentration in the environment the MoS₂ is converted into either MoO₃ or MoO₂. To elucidate the specific mechanism of this reaction, density functional theory (DFT) calculations were performed including the van der Walls dispersion correction. We show that the S-vacancy formation energy as well as O substitution energy are lowered with increasing O content. DFT calculations show that at high O contents in MoS_2−xO_x the P2₁/c phase is energetically preferred over the 2H-MoS₂ structure. A P-T phase diagram of the Gibbs free energy obtained from DFT shows that the partial O pressure tunes whether MoO₃ or MoO₂ is the dominant product of the reaction. We explored the band structure of multiple vacancies in MoS₂ and find additional in-gap states compared to the monovacancy. Our results offer insight into the conditions that control the degradation of MoS₂-based devices.

[1] J. Gao, et al., ACS Nano, 10 (2), 2628 (2016)

Keywords: transition metal dichalcogenides; Density functional theory; 2D-Materials; Ab-initio Thermodynamics; vt-Raman