Full dispersion versus Debye model evaluation of lattice thermal conductivity with a Landauer approach

Changwook Jeong, Birck Nanotechnology Center, Purdue University
Supriyo Datta, Birck Nanotechnology Center, Purdue University
Mark S. Lundstrom, Birck Nanotechnology Center, Purdue University

Date of this Version



J. Appl. Phys. 109, 073718 (2011)


Copyright (2011) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in J. Appl. Phys. 109, 073718 (2011) and may be found at http://dx.doi.org/10.1063/1.3567111. The following article has been submitted to/accepted by Journal of Applied Physics. Copyright (2011) Changwook Jeong, Supriyo Datta and Mark Lundstrom. This article is distributed under a Creative Commons Attribution 3.0 Unported License.


Using a full dispersion description of phonons, the thermal conductivities of bulk Si and Bi(2)Te(3) are evaluated using a Landauer approach and related to the conventional approach based on the Boltzmann transport equation. A procedure to extract a well-defined average phonon mean-free-path from the measured thermal conductivity and given phonon-dispersion is presented. The extracted mean-free-path has strong physical significance and differs greatly from simple estimates. The use of simplified dispersion models for phonons is discussed, and it is shown that two different Debye temperatures must be used to treat the specific heat and thermal conductivity (analogous to the two different effective masses needed to describe the electron density and conductivity). A simple technique to extract these two Debye temperatures is presented and the limitations of the method are discussed. (C) 2011 American Institute of Physics. [doi:10.1063/1.3567111]


Nanoscience and Nanotechnology