Van der Waals epitaxial growth of 2D materials and heterostructures with in situ diagnostics

Controlled synthesis of large-area, single crystalline 2D materials and heterostructures with preferred stacking configurations is crucial for their applications in large scale 3D integration for microelectronics. In this talk, I will present our recent work on understanding and controlling the interactions between substrates and 2D materials to form well-defined twin grain boundaries and heterostructures through van der Waals epitaxial growth. We utilized in situ TEM, real time laser spectroscopy, z-contrast STEM imaging, and DFT calculation elucidate the fundamental growth mechanism of the crystallization and coalescence of amorphous precursors as they guided by 2D crystalline templates into bilayers or heterostructures. This work was supported by the U.S. DOE, Office of Science, Materials Sciences and Engineering Division and the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility.