Abstract
The wide measured range of thermal conductivities (k) for monolayer MoS2 and the corresponding incongruent calculated values in the literature all suggest that extrinsic defect thermal resistance is significant and varied in synthesized samples of this material. Here we present defect-mediated thermal transport calculations of MoS2 using interatomic forces derived from density functional theory combined with Green's function methods to describe phonon-point-defect interactions and a Peierls-Boltzmann formalism for transport. Conductivity calculations for bulk and monolayer MoS2 using different density functional formalisms are compared. Nonperturbative first-principles methods are used to describe defect-mediated spectral functions, scattering rates, and phonon k, particularly from sulfur vacancies (VS), and in the context of the plethora of measured and calculated literature values. We find that k of monolayer MoS2 is sensitive to phonon-VS scattering in the range of experimentally observed densities, and that first-principles k calculations using these densities can explain the range of measured values found in the literature. Furthermore, measured k values for bulk MoS2 are more consistent because VS defects are not as prevalent.
Original language | English |
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Article number | 014004 |
Journal | Physical Review Materials |
Volume | 4 |
Issue number | 1 |
DOIs | |
State | Published - Jan 16 2020 |
Funding
This work was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Material Sciences and Engineering Division. Computational resources were provided by the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility supported by the Office of Science of the US Department of Energy under Contract No. DE-AC02- 05CH11231.
Funders | Funder number |
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U.S. Department of Energy | |
Office of Science | DE-AC02- 05CH11231 |
Basic Energy Sciences |