Dielectric properties of hexagonal boron nitride and transition metal dichalcogenides: from monolayer to bulk." npj 2D Materials and Applications 2 (1): 6, doi: 10.1038/s41699-018-0050-x This document is being made freely available by the Eugene McDermott Library of the University of Texas at Dallas with permission of the copyright owner

摘要: The continued miniaturization of silicon-based electronics along with the exfoliation of graphene from graphite has motivated extensive research toward layered two-dimensional (2D) materials. However, since graphene does not have a band-gap, it is not well suited for digital electronics applications. 1 Consequently, significant research effort has been directed toward 2D semiconductors. Indeed several classes of 2D semiconductors like boron-nitride (h-BN), transition metal dichalcogenides (TMDs), silicene, phosphorene, layered transition metal oxides, and hydroxides have been studied in the recent past. 2-5TMDs are layered materials with chemical formula MX2 where M is a transition metal and X is a chalcogen. Many different TMDs are possible because of the various permutations of the transition metal and the chalcogen that can be made. TMDs are either metallic, semi-metallic, semiconductors, topological insulators, or superconductors. 6-8 As most of the semiconducting TMDs have a bandgap 9< 2eV, they are great candidates for future electronic devices. 10 In addition, their atomically thin nature enables further miniaturization of electronic devices. Also, many monolayer TMDs have a direct bandgap, enabling their use in the field of optoelectronics. 11 Structurally, TMDs have strong in-plane covalent bonding and weak out-of-plane van der Waals bonding. Just like in graphene, the weak van der Waals force between the layers facilitates exfoliation of individual or multiple layers. The versatility of the electronic and optical properties of layered materials (TMDs) and the ability to exfoliate monolayers and few layers has propelled …