79 research outputs found
Thermal conductivity of monolayer MoS2, MoSe2, and WS2: Interplay of mass effect, interatomic bonding and anharmonicity
Phonons are essential for understanding the thermal properties in monolayer
transition metal dichalcogenides, which limit their thermal performance for
potential applications. We investigate the lattice dynamics and thermodynamic
properties of MoS2, MoSe2, and WS2 by first principles calculations. The
obtained phonon frequencies and thermal conductivities agree well with the
measurements. Our results show that the thermal conductivity of MoS2 is highest
among the three materials due to its much lower average atomic mass. We also
discuss the competition between mass effect, interatomic bonding and anharmonic
vibrations in determining the thermal conductivity of WS2. Strong covalent W-S
bonding and low anharmonicity in WS2 are found to be crucial in understanding
its much higher thermal conductivity compared to MoSe2.Comment: 19 pages, 7 figure
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