State-of-the-Art Characterization Methods and Computational Approaches for Elucidating the Epitaxial Growth of 2D Materials

Two-dimensional (2D) materials have attracted significant attention due to their unique properties and potential for next-generation devices. Among synthesis methods, epitaxial growth via chemical vapor deposition offers a promising route to produce high-quality 2D films with precise crystallographic alignment. This review focuses on advanced analytical techniques and theoretical models that elucidate the mechanisms underlying epitaxial growth, with particular emphasis on unidirectional growth in non-centrosymmetric materials such as hexagonal boron nitride and transition metal dichalcogenides. These materials exhibit three-fold symmetry, resulting in two equivalent domain orientations that require specialized methods for differentiation. We discuss microscopy, spectroscopy, and electron diffraction techniques that reveal domain orientation and alignment, as well as density functional theory and related computational approaches that provide atomic-scale insights into adsorption energies, surface terminations, and step-edge effects. Despite significant progress, challenges remain in achieving reproducible wafer-scale single-crystal growth, necessitating further integration of experimental and theoretical methodologies.