Abstract
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.
Keywords
antimony compounds; bismuth compounds; heat transfer; phonons; superlattices; thermal conductivity, THERMAL-CONDUCTIVITY REDUCTION; THERMOELECTRIC PERFORMANCE; TRANSPORT
DOI
10.1063/1.3483767
Citation
Acoustic phonon scattering in Bi2Te3/Sb2Te3Bi2Te3/Sb2Te3 superlattices. Yaguo Wang, Carl Liebig, Xianfan Xu, and Rama Venkatasubramanian Appl. Phys. Lett. 97, 083103 (2010); doi: http://dx.doi.org/10.1063/1.3483767
Date of this Version
8-2010
Recommended Citation
Wang, Yaguo; Liebig, Carl; Xu, Xianfan; and Venkatasubramanian, Rama, "Acoustic phonon scattering in Bi2Te3/Sb2Te3 superlattices" (2010). Birck and NCN Publications. Paper 641.
http://dx.doi.org/10.1063/1.3483767
Comments
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 http://dx.doi.org/10.1063/1.3483767. 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.