Stacking change in MoS₂ bilayers induced by interstitial Mo impurities.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Molybdenum disulfide (MoS₂) is a layered material with tunable electronic properties.
• Understanding impurity effects is crucial for advanced material design.
• Bilayer stacking significantly influences MoS₂ properties.

Purpose of the Study:

• To investigate the electronic and structural impacts of molybdenum (Mo) impurities in MoS₂ bilayers.
• To determine how Mo impurities affect the stability and stacking order of MoS₂ bilayers.
• To explore the resulting electronic structures and potential applications.

Main Methods:

• Theoretical calculations were employed to model Mo impurities within MoS₂ bilayers.
• Analysis of electronic band structures and defect states was performed.
• Energetic stability of different impurity configurations and stacking orders was evaluated.

Main Results:

• Interstitial Mo impurities reverse the intrinsic AA' stacking stability to AB' in MoS₂ bilayers.
• Mo impurities introduce split electronic levels within the band gap, influenced by crystal fields.
• Stable Mo configurations are associated with compact accommodation in hollow sites, affecting interlayer distances and band gaps.

Conclusions:

• Mo impurities fundamentally alter MoS₂ bilayer structural stability and electronic characteristics.
• The findings suggest potential applications in exciton trapping and controlled bilayer growth.
• This study provides insights into defect engineering for 2D materials.