First-principles study on the electronic structures of ternary TMDC alloys in monolayer and multilayer forms*

Transition metal dichalcogenides (TMDCs) have attracted great attention for their potential application in many fields including light-emitting diodes and photo detectors. The possibility in controlling the stacking sequence of different kind of TMDC layers by means of van der Waals epitaxy enables us to design novel materials through electronic structure engineering. Recently, two-dimensional lateral heterostructures have been successfully synthesized by Sahoo et al. [1], providing us a new freedom in heterostructure design other than sequential stacking. We have investigated the electronic structures of a monolayer and multilayers of ternary alloys made of Mo_(1-x)W_xS₂ by using PHASE/0 [2], a first-principles electronic structure calculation code. We obtain a direct energy band gap whose width is smaller than both MoS2 and WS2. Details of the results will be given in the presentation.

We used the NIMS Numerical Materials Simulator for the calculations.

[1] P. K. Sahoo, et al, Nature 553, 63 (2018).
[2] T. Yamasaki et al, Comp. Phys. Comm. 244, 264 (2019).