Ultralow Thermal Conductivity in Disordered, Layered WSe2 Crystals
Catalin Chiritescu,1
David G. Cahill,1*
Ngoc Nguyen,2
David Johnson,2
Arun Bodapati,3
Pawel Keblinski,3
Paul Zschack4
The cross-plane thermal conductivity of thin films of WSe
2 grown
from alternating W and Se layers is as small as 0.05 watts per
meter per degree kelvin at room temperature, 30 times smaller
than the
c-axis thermal conductivity of single-crystal WSe
2 and a factor of 6 smaller than the predicted minimum thermal
conductivity for this material. We attribute the ultralow thermal
conductivity of these disordered, layered crystals to the localization
of lattice vibrations induced by the random stacking of two-dimensional
crystalline WSe
2 sheets. Disordering of the layered structure
by ion bombardment increases the thermal conductivity.
2 Department of Chemistry, University of Oregon, Eugene, OR 97403, USA.
3 Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
4 Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA.
* To whom correspondence should be addressed. E-mail: d-cahill{at}uiuc.edu
