Band structure modulation in MoS2 multilayers and heterostructures through electric field and strain

We use density functional theory to investigate the effect of finite external electric fields along with strain on the electronic structure of MoS2 multilayers and heterostructures composed of MoS2/MoSe2/MoS2 and MoS2/WS2/MoS2. We find that the presence of an electric field decreases the values of both direct and indirect band gaps, in agreement with earlier works. However, when either compressive or tensile strain is applied to the system the strength of the coupling between the electric field and direct band gap is increased while the coupling strength between the electric field and the indirect band gap is decreased. In contrast, in the heterostructures the coupling with the direct band gap remains unchanged while the coupling with indirect band gap is decreased. Taken together, these results show rich behavior of the electric field effects in MoS2 multilayers and heterostructures. (C) 2015 Elsevier B.V. All rights reserved.