Computational study of the Seebeck coefficient of one-dimensional composite nano-structures

Raseong Kim, Birck Nanotechnology Center, Purdue University
Mark S. Lundstrom, Birck Nanotechnology Center, Purdue University

Date of this Version



Journal of Applied Physics: Volume 110, Issue 3


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 Journal of Applied Physics: Volume 110, Issue 3 and may be found at The following article has been submitted to/accepted by Journal of Applied Physics. Copyright (2011) Raseong Kim and Mark S. Lundstrom. Attribution 3.0 Unported License.


The Seebeck coefficient (S) of composite nano-structures is theoretically explored within a self-consistent electro-thermal transport simulation framework using the non-equilibrium Green's function method and a heat diffusion equation. Seebeck coefficients are determined using numerical techniques that mimic experimental measurements. Simulation results show that, without energy relaxing scattering, the overall S of a composite structure is determined by the highest barrier within the device. For a diffusive, composite structure with energy relaxation due to electron-phonon scattering, however, the measured S is an average of the position-dependent values with the weighting factor being the lattice temperature gradient. The results stress the importance of self-consistent solutions of phonon heat transport and the resulting lattice temperature distribution in understanding the thermoelectric properties of a composite structure. It is also clarified that the measured S of a composite structure reflects its power generation performance rather than its cooling performance. The results suggest that the lattice thermal conductivity within the composite structure might be engineered to improve the power factor over the bulk by avoiding the conventional trade-off between S and the electrical conductivity. (C) 2011 American Institute of Physics. [doi:10.1063/1.3619855]


Nanoscience and Nanotechnology