Intrinsic Thermal conductivities of monolayer transition metal dichalcogenides MX2 (M = Mo, W; X = S, Se, Te)

The successful synthesis of the single to few layer transition metal dichalcogenides has opened a new era in the nanoelectronics. For their efficient implementations in the electronic devices while taking care of their overheating issues, the characterization of their thermal transport properties is extremely vital. So, we have systematically investigated the thermal transport properties of monolayer transition metal dichalcogenides MX2 (M = Mo, W; X= S, Se, Te) by combining the first-principles calculations with Boltzmann transport equation. We find that monolayer WTe2 possesses the lowest lattice thermal conductivity kappa(L) (33:66 Wm(-1) K-1 at 300 K) among these six semiconducting materials, in contrast to the highest kappa(L) (113:97Wm(-1) K-1 at 300 K) of WS2 among them. Further analyses reveal that the higher (lower) an harmonic and isotopic scatterings together with the lower (higher) phonon group velocities lead to the lowest (highest) value of kappa(L) in WTe2 (WS2) monolayer. In addition, we have also calculated the cumulative thermal conductivity kappa(C) as a function of mean free path, which indicates that the nanostructures with the length of about 400 nm would reduce kappa(L) drastically. These results offer important understanding from thermal conductivity point of view to design the 2D transition metal dichalcogenides MX2 (M = Mo, W; X = S, Se, Te) electronics.