Atomistic Probing of Defect-Engineered 2H-MoTe₂ Monolayers.

Area of Science:

• Materials Science
• Nanotechnology
• Condensed Matter Physics

Background:

• Point defects significantly influence the properties of 2D materials.
• Understanding defect formation is key for advancing 2D material-based nanotechnology.

Purpose of the Study:

• To directly probe and classify point defects in 2H-MoTe2 monolayers.
• To investigate the effects of vacuum annealing and laser illumination on defect generation and material properties.

Main Methods:

• Direct probing of point defects in 2H-MoTe2 monolayers.
• Exposure to 200 °C-vacuum-annealing and 532 nm-laser-illumination.
• Classification and quantification of defects using a deep learning algorithm.

Main Results:

• Tellurium-related defects were predominantly observed.
• Vacuum annealing induced n-type conductivity by creating tellurium vacancies/adatoms.
• Laser illumination led to p-type conductivity via oxygen adsorption at tellurium vacancies.

Conclusions:

• Different treatments create distinct point defects in 2H-MoTe2.
• This defect engineering approach allows modulation of electronic properties.
• Findings are critical for developing functional nanoscale devices from 2D materials.