Enhancing the Thermoelectric Properties of Layered Transition-Metal Dichalcogenides 2H-MQ2 (M = Mo, W; Q = S, Se, Te) by Layer Mixing: Density Functional Investigation

We explored how to improve the thermoelectric properties of the layered transition-metal dichalcogenides 2H-MQ(2) (M = Mo, W; Q = S, Se, Te) by comparing the thermoelectric properties of hypothetical mixed-layer systems 2H-MQ(2)/2H-MQ(2)', in which two different layers 2H-MQ(2) and 2H-MQ(2)' (Q, Q' = S, Se, Te) alternate, with those of their pure components on the basis of density functional calculations. Our study predicts that the mixed-layer compounds MS2/MTe2 (M = Mo, W) strongly enhance the thermoelectric properties as a consequence of reducing the band gap and the interlayer van der Waals interactions. The layer-mixing is predicted to be a promising way of improving the thermoelectric properties of 2H-MQ(2.)