Layer thickness-dependent phonon properties and thermal conductivity of MoS2
- 28 February 2016
- journal article
- research article
- Published by AIP Publishing in Journal of Applied Physics
- Vol. 119 (8), 085106
- https://doi.org/10.1063/1.4942827
Abstract
For conventional materials, the thermal conductivity of thin films is usually suppressed when the thickness decreases due to phonon-boundary scattering. However, this is not necessarily true for the van der Waals solids if the thickness is reduced to only a few layers. In this letter, the layer thickness-dependent phonon properties and thermal conductivity in the few-layer MoS2 are studied using the first-principles-based Peierls-Boltzmann transport equation approach. The basal-plane thermal conductivity of 10-μm-long samples is found to monotonically reduce from 138 W/mK to 98 W/mK for naturally occurring MoS2, and from 155 W/mK to 115 W/mK for isotopically pure MoS2, when its thickness increases from one layer to three layers. The thermal conductivity of tri-layer MoS2 approaches to that of bulk MoS2. Both the change of phonon dispersion and the thickness-induced anharmonicity are important for explaining such a thermal conductivity reduction. The increased anharmonicity in bi-layer MoS2 results in stronger phonon scattering for ZAi modes, which is linked to the breakdown of the symmetry in single-layer MoS2.Keywords
Funding Information
- National Science Foundation (1511195)
- Defense Advanced Research Projects Agency (FA8650-15-1-7524)
This publication has 52 references indexed in Scilit:
- Anharmonic properties from a generalized third-orderab initioapproach: Theory and applications to graphite and graphenePhysical Review B, 2013
- Single-layer MoS2 transistorsNature Nanotechnology, 2011
- Dimensional crossover of thermal transport in few-layer grapheneNature Materials, 2010
- Avoided crossing of rattler modes in thermoelectric materialsNature Materials, 2008
- Enhanced thermoelectric performance of rough silicon nanowiresNature, 2008
- Thermal conductivity of simple and tubular nanowire composites in the longitudinal directionPhysical Review B, 2005
- Thermal conductivity modeling of periodic two-dimensional nanocompositesPhysical Review B, 2004
- Partially coherent phonon heat conduction in superlatticesPhysical Review B, 2003
- Theoretical Study of the Lattice Thermal Conductivity in Ge Framework SemiconductorsPhysical Review Letters, 2001
- Relativistic separable dual-space Gaussian pseudopotentials from H to RnPhysical Review B, 1998