1304.4831 (E. Cappelluti et al.)

Tight-binding model and direct-gap/indirect-gap transition in
single-layer and multi-layer MoS$_2$    [PDF]

E. Cappelluti, R. Roldán, J. A. Silva-Guillén, P. Ordejón, F. Guinea

In this paper we present a paradigmatic tight-binding model for single-layer as well as for multi-layered semiconducting MoS$_2$ and similar transition metal dichalcogenides. We show that the electronic properties of multilayer systems can be reproduced in terms of a tight-binding modelling of the single-layer hopping terms by simply adding the proper interlayer hoppings ruled by the chalcogenide atoms. We show that such tight-binding model permits to understand and control in a natural way the transition between a direct-gap band structure, in single-layer systems, to an indirect gap in multilayer compounds in terms of a momentum/orbital selective interlayer splitting of the relevant valence and conduction bands. The model represents also a suitable playground to investigate in an analytical way strain and finite-size effects.

View original: http://arxiv.org/abs/1304.4831