Anisotropic thermal conductivity of MoS2 nanoribbons: Chirality and edge effects

Previous studies of the thermal transport in MoS2 are limited to the 0 degrees (zigzag) and 30 degrees (armchair) chiralities. We investigate the anisotropic thermal transport properties of MoS2 nanoribbons with various crystal chiralities by employing the full-band phonon dispersion relations obtained from first-principle calculations. The ribbons with chiralities other than 0 degrees and 30 degrees always have lower thermal conductivity, yet a local maximum at 19.1 degrees. In addition, the thermal conductivity can be further decreased by increasing the edge roughness due to the largely degraded longitudinal phonons. These findings suggest possibilities of obtaining a higher thermoelectric efficiency in MoS2 nanoribbons. (C) 2014 AIP Publishing LLC.