Acoustic phonon scattering in Bi2Te3/Sb2Te3 superlattices

Yaguo Wang, Purdue University
Carl Liebig, Purdue University - Main Campus
Xianfan Xu, Birck Nanotechnology Center, School of Materials Engineering, Purdue University
Rama Venkatasubramanian, RTI Int

Date of this Version



Acoustic phonon scattering in Bi2Te3/Sb2Te3Bi2Te3/Sb2Te3 superlattices. Yaguo Wang, Carl Liebig, Xianfan Xu, and Rama Venkatasubramanian Appl. Phys. Lett. 97, 083103 (2010); doi:

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Copyright (2010) 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 Appl. Phys. Lett. 97, 083103 (2010) and may be found at The following article has been submitted to/accepted by Applied Physics Letters. Copyright (2010) Yaguo Wang, Carl Liebig, Xianfan Xu, and Rama Venkatasubramanian. This article is distributed under a Creative Commons Attribution 3.0 Unported License.


Ultrafast time-resolved measurements were conducted to investigate long-wavelength acoustic phonon scattering and velocity reduction in Bi2Te3/Sb2Te3 superlattices. We show that both these phenomena suppress heat transfer process, with the phonon scattering contributing more in differentiating the lattice thermal conductivities among films with different periods. Measurements of reduction in the acoustic phonon amplitudes support the decrease in the thermal conductivity for certain superlattice periods, which is not predicted by acoustic mismatch theory. This study is a direct measurement of coherent acoustic phonons in superlattices which is of significant interest to thermoelectrics.


Engineering | Nanoscience and Nanotechnology