Atomic interaction through two-dimensional materials governed by competitive energy fluctuations

The rapid development of hybrid 2D materials has unveiled its potential to achieve complex functionality. The impact of 2D materials on intermolecular interactions of crystalline materials has not been fully understood. In this study, we computationally investigated a variety of heterojunctions with 2D materials sandwiched by 3D crystal layers.^[1]The results suggest that transparency of 2D interlayer is governed by competition between the substrate potential energy fluctuation attenuated, and the binding energy fluctuation generated by 2D interlayer. Although the potential field from covalent-bonded materials is screened by a monolayer of graphene, that from ionic-bonded materials is strong enough to penetrate through a few layers of graphene. Such field penetration is substantially attenuated by 2D hBN, which itself has polarization in its atomic bonds. The insight has been verified by our experiments and further employed to control the transparency via modulating the nature and thickness of 2D interlayer, which eventually leads to the successful remote epitaxial growth of single-crystalline materials across the periodic table.
[1] W. Kong, H. Li, K. Qiao, J.C. Grossman, J. Kim et al., Nat. Mater. 2018