In the emerging world of twisted bilayer structures, the possible configurations are limitless, which enables for a rich landscape of electronic properties. In this paper, we focus on twisted bilayer transition metal dichalcogenides (TMDCs) and study its properties by means of an accurate tight-binding model. We build structures with different angles and find that the so-called flatbands emerge when the twist angle is sufficiently small (around 7.3∘). Interestingly, the band gap can be tuned up to a 2.2\% (51 meV) when the twist angle in the relaxed sample varies from 21.8∘ to 0.8∘. Furthermore, when looking at local density of states we find that the band gap varies locally along the moir\`e pattern due to the change in the coupling between layers at different sites. Finally, we also find that the system can suffer a transition from a semiconductor to a metal when a sufficiently strong electric field is applied. Our study can serve as a guide for the practical engineering of the TMDCs based optoelectronic devices.
@article{arxiv.2005.13879,
title = {Tuning band gaps in twisted bilayer MoS$_2$},
author = {Yipei Zhang and Zhen Zhan and Francisco Guinea and Jose Angel Silva-Guillen and Shengjun Yuan},
journal= {arXiv preprint arXiv:2005.13879},
year = {2021}
}