  As the energy problem becomes more prominent, researches on thermoelectric
(TE) materials have deepened over the past few decades. Low thermal
conductivity enables thermoelectric materials better thermal conversion
performance. In this study, based on the first principles and phonon Boltzmann
transport equation, we studied the thermal conductivities of single-layer WSe2
under several defect conditions using density functional theory (DFT) as
implemented in the Vienna Ab-initio Simulation Package (VASP). The lattice
thermal conductivities of WSe2 under six kinds of defect states, i.e., PS,
SS-c, DS-s, SW-c, SS-e, and DS-d, are 66.1, 41.2, 39.4, 8.8, 42.1, and 38.4
W/(m2K), respectively at 300 K. Defect structures can reduce thermal
conductivity up to 86.7% (SW-c) compared with perfect structure. The influences
of defect content, type, location factors on thermal properties have been
discussed in this research. By introducing atom defects, we can reduce and
regulate the thermal property of WSe2, which should provide an interesting idea
for other thermoelectric materials to gain a lower thermal conductivity.
