Three-dimensional epitaxial heterostructures are based on covalently-bonded interfaces, whereas those from 2-dimensional (2D) materials exhibit van der Waals interactions. Under the right conditions, however, material structures with mixed interfacial van der Waals and covalent bonding may be realized. Atomically thin layers formed at the epitaxial graphene (EG)/silicon carbide (SiC) interface indicate that EG/SiC interfaces provide this unique environment and enable synthesis of a rich palette of 2D materials not accessible with traditional techniques. Here, we demonstrate a method termed confinement heteroepitaxy (CHet), to realize air-stable, structurally unique, crystalline 2D-Ga, In, and Sn at the EG/SiC interface. The first intercalant layer is covalently-bonded to the SiC, and is accompanied by a vertical bonding gradient that ends with van der Waals interactions. Such structures break out of plane centrosymmetry, thereby introducing atomically thin, non-centrosymmetric 2D allotropes of 3D materials as a foundation for tunable superconductivity, topological states, and plasmonic properties.
@article{arxiv.1905.09962,
title = {Confinement Heteroepitaxy: Realizing Atomically Thin, Half-van der Waals Materials},
author = {Natalie Briggs and Brian Bersch and Yuanxi Wang and Nadire Nayir and Roland J. Koch and Ke Wang and Marek Kolmer and Wonhee Ko and Ana De La Fuente Duran and Shruti Subramanian and Chengye Dong and Jeffrey Shallenberger and Aaron Bostwick and Chris Jozwiak and Eli Rotenberg and An-Ping Li and Adri C. T. van Duin and Vincent Crespi and Joshua Robinson},
journal= {arXiv preprint arXiv:1905.09962},
year = {2019}
}
Comments
10 pages of main text with 3 figures, 21 pages of SI with 15 figures and 1 table