Catalyzed Kinetic Growth in Two-Dimensional MoS₂.

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Controlling the morphology of two-dimensional (2D) materials during chemical vapor deposition (CVD) growth is challenging.
• Off-equilibrium growth can yield non-Wulff shapes with potential utility, but controllable methods are lacking.

Purpose of the Study:

• To achieve controllable kinetic growth of 2D materials with non-equilibrium shapes.
• To explore novel growth mechanisms for engineering 2D material morphology.

Main Methods:

• Utilized potassium chloride (KCl) as a catalyst for CVD growth of 2D molybdenum disulfide (MoS2).
• Employed plasma pretreatment on growth substrates to access deep kinetic growth regimes.
• Investigated the growth mechanism using theoretical rationalization based on kinetic instability.

Main Results:

• Achieved unprecedented non-equilibrium high-index faceting and unusual high-symmetry shapes in 2D MoS2.
• Identified a novel vapor-liquid-adatom-solid (VLAS) growth mechanism involving synergistic capture and adatom diffusion.
• Demonstrated high-quality, rapid, and controllable synthesis of non-Wulff shapes.

Conclusions:

• The developed method provides a controllable approach for kinetic growth of 2D materials.
• The VLAS mechanism offers opportunities for advanced shape engineering of 2D transition metal dichalcogenides.
• This facilitates the development of 2D materials with tailored morphologies for diverse applications.