Pressure-Controlled Layer-by-Layer to Continuous Oxidation of ZrS₂(001) Surface

Area of Science:

• Materials Science
• Surface Chemistry
• Computational Nanoscience

Background:

• Layered semiconducting transition-metal dichalcogenides (TMDCs) require understanding oxidation mechanisms for controlled oxide and oxysulfide synthesis.
• Native oxide formation on TMDCs impacts device performance and material properties.

Purpose of the Study:

• To investigate the influence of oxygen partial pressure on the oxidation mechanisms of zirconium disulfide (ZrS2).
• To elucidate the relationship between oxidation conditions, oxide morphology, and quality at an atomic level.
• To provide a foundation for pressure-controlled synthesis of TMDC-based oxides and oxysulfides.

Main Methods:

• Utilized reactive molecular dynamics simulations to model the oxidation process of ZrS2.
• Analyzed the effect of varying oxygen partial pressures on oxidation kinetics and pathways.
• Compared simulation results with established oxidation models like the Deal-Grove model.

Main Results:

• Oxygen partial pressure dictates both the rate and morphology of ZrS2 oxidation.
• Observed a transition from layer-by-layer oxidation to continuous, amorphous-oxide-mediated oxidation.
• Identified distinct oxidation stages governed by different mechanisms (bond-switching vs. Deal-Grove kinetics) at varying pressures.

Conclusions:

• Atomistic insights into pressure-controlled oxidation of TMDCs are provided.
• Demonstrated that selective exposure of oxidation stages is achievable through precise pressure control.
• This study offers a pathway for rational design and synthesis of TMDC-derived materials.