Epitaxy of 2D Materials toward Single Crystals

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) materials possess unique properties making them suitable for electronics and optoelectronics.
• Large-size single-crystal 2D materials are crucial for integrated devices.
• Epitaxy on single-crystal substrates is the primary method for growing 2D single crystals.

Purpose of the Study:

• To present four distinct epitaxy modes for 2D material growth.
• To discuss the factors influencing epitaxy behavior.
• To summarize future opportunities and challenges in 2D single-crystal epitaxy.

Main Methods:

• Review and presentation of four epitaxy modes: van der Waals epitaxy, edge epitaxy, step-guided epitaxy, and in-plane epitaxy.
• Systematic discussion of lattice symmetry and material-substrate interactions.
• Focus on the growth of graphene, hexagonal boron nitride (h-BN), and transition metal dichalcogenides (TMDCs).

Main Results:

• Four epitaxy modes are identified and explained for controlled 2D material growth.
• Lattice symmetry and substrate interactions are key determinants of epitaxy.
• Seamless stitching of 2D domains is achieved when orientations align.

Conclusions:

• Epitaxy is essential for producing large-scale, single-crystal 2D films.
• Understanding epitaxy mechanisms is vital for advancing 2D material applications.
• Future research should address challenges and explore new opportunities in 2D single-crystal synthesis.