Ab Initio Molecular Dynamics Simulation Study of Oxidation of ZrS₂(001)

<b>Abstract</b><br/><br/>In transition metal dichalcogenides (TMDC) family, ZrS₂ is known for its superior electrical and chemical catalytic properties. Meanwhile, it is easily oxidized, which brings problems in device processing and long-term stability. Although the ZrS₂ oxidation mechanism and oxide growth kinetics has been investigated recently, the atomistic reaction pathway still lacks fully understood. Here, we report <i>ab initio</i> molecular dynamics results for studying the oxidation of ZrS₂. Our simulations show the oxidation of ZrS₂(001) surface to be initiated as the adsorption of an oxygen molecule to the ZrS₂(001) surface, followed by oxygen atoms substituting surface sulfur atoms. The recently reported amorphization-assisted-oxidation is found to be linked to the zirconium atoms bonded with inner layer sulfur atoms. We also found the oxygen transport is assisted by bond switching and ring arrangements. The chemical reaction pathways and atomistic mechanisms provided in this work is valuable for device processing and other layered TMDC oxidation.<br/><br/><br/><b>Acknowledgements</b><br/><br/>This work was supported as part of the Computational Materials Sciences Program funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Award Number DE-SC0014607.