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Phonon Transport in SiGe-Based Nanocomposites and Nanowires for Thermoelectric Applications

Published online by Cambridge University Press:  16 March 2015

M. Upadhyaya
Affiliation:
Electrical and Computer Engineering, University of Massachusetts-Amherst Amherst, MA 01003, U.S.A.
Z. Aksamija
Affiliation:
Electrical and Computer Engineering, University of Massachusetts-Amherst Amherst, MA 01003, U.S.A.
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Abstract

Silicon-germanium (SiGe) superlattices (SLs) have been proposed for application as efficient thermoelectrics because of their low thermal conductivity, below that of bulk SiGe alloys. However, the cost of growing SLs is prohibitive, so nanocomposites, made by a ball-milling and sintering, have been proposed as a cost-effective replacement with similar properties. Lattice thermal conductivity in SiGe SLs is reduced by scattering from the rough interfaces between layers. Therefore, it is expected that interface properties, such as roughness, orientation, and composition, will play a significant role in thermal transport in nanocomposites and offer many additional degrees of freedom to control the thermal conductivity in nanocomposites by tailoring grain size, shape, and crystal angle distributions. We previously demonstrated the sensitivity of the lattice thermal conductivity in SLs to the interface properties, based on solving the phonon Boltzmann transport equation under the relaxation time approximation. Here we adapt the model to a broad range of SiGe nanocomposites. We model nanocomposite structures using a Voronoi tessellation to mimic the grains and their distribution in the nanocomposite and show excellent agreement with experimentally observed structures, while for nanowires we use the Monte Carlo method to solve the phonon Boltzmann equation. In order to accurately treat phonon scattering from a series of atomically rough interfaces between the grains in the nanocomposite and at the boundaries of nanowires, we employ a momentum-dependent specularity parameter. Our results show thermal transport in SiGe nanocomposites and nanowires is reduced significantly below their bulk alloy counterparts.

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Articles
Copyright
Copyright © Materials Research Society 2015 

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References

REFERENCES

Hicks, L. and Dresselhaus, M., “Thermoelectric figure of merit of a one-dimensional conductor,” Phys. Rev. B, vol. 47, p. 16631, 1993.CrossRefGoogle ScholarPubMed
Snyder, G. J. and Toberer, E. S., “Complex thermoelectric materials,” Nature Mater., vol. 7, pp. 105114, 2008.CrossRefGoogle ScholarPubMed
Lan, Y., Minnich, A. J., Chen, G., and Ren, Z., “Enhancement of thermoelectric Figure-of-Merit by a bulk nanostructuring approach,” Adv. Func. Mater., vol. 20, no. 3, pp. 357376, 2010.CrossRefGoogle Scholar
Lan, Y., Poudel, B., Ma, Y., Wang, D., Dresselhaus, M. S., Chen, G., and Ren, Z., “Structure study of bulk nanograined thermoelectric bismuth antimony telluride,” Nano Lett., vol. 9, pp. 14191422, 2009.CrossRefGoogle ScholarPubMed
Nan, C.-W., Birringer, R., Clarke, D. R., and Gleiter, H., “Effective thermal conductivity of particulate composites with interfacial thermal resistance,” J. Appl. Phys., vol. 81, pp. 66926699, 1997.CrossRefGoogle Scholar
Savvides, N. and Goldsmid, H. J., “Boundary scattering of phonons in fine-grained hot-pressed ge-si alloys. ii. theory,” J. Phys. C: Solid State Phys., vol. 13, p. 4671, 1980.CrossRefGoogle Scholar
Wang, Z., Alaniz, J. E., Jang, W., Garay, J. E., and Dames, C., “Thermal conductivity of nanocrystalline silicon: Importance of grain size and frequency-dependent mean free paths,” Nano Lett., vol. 11, no. 6, pp. 22062213, 2011.CrossRefGoogle ScholarPubMed
Zebarjadi, M., Esfarjani, K., Bian, Z., and Shakouri, A., “Low-temperature thermoelectric power factor enhancement by controlling nanoparticle size distribution,” Nano Lett., vol. 11, pp. 225230, 2011.CrossRefGoogle ScholarPubMed
Biswas, K., He, J., Blum, I. D., Wu, C.-I., Hogan, T. P., Seidman, D. N., Dravid, V. P., and Kanatzidis, M. G., “High-performance bulk thermoelectrics with all-scale hierarchical architectures,” Nature, vol. 489, pp. 414418, 2012.CrossRefGoogle ScholarPubMed
Aksamija, Z. and Knezevic, I., “Thermal conductivity of si1-x ge x /si1-y ge y superlattices: Competition between interfacial and internal scattering,” Phys. Rev. B, vol. 88, p. 155318, 2013.CrossRefGoogle Scholar
Aksamija, Z., “Lattice thermal transport in si-based nanocomposites for thermoelectric applications,” J. Electron. Mater., pp. 17, 2014.Google Scholar
McGaughey, A. J. H. and Jain, A., “Nanostructure thermal conductivity prediction by monte carlo sampling of phonon free paths,” Appl. Phys. Lett., vol. 100, no. 6, p. 061911, 2012.CrossRefGoogle Scholar
Aksamija, Z. and Knezevic, I., “Anisotropy and boundary scattering in the lattice thermal conductivity of silicon nanomembranes,” Phys. Rev. B, vol. 82, p. 045319, 2010.CrossRefGoogle Scholar
Wang, X. W., Lee, H., Lan, Y. C., Zhu, G. H., Joshi, G., Wang, D. Z., Yang, J., Muto, A. J., Tang, M. Y., Klatsky, J., Song, S., Dresselhaus, M. S., Chen, G., and Ren, Z. F., “Enhanced thermoelectric figure of merit in nanostructured n-type silicon germanium bulk alloy,” Appl. Phys. Lett., vol. 93, no. 19, p. 193121, 2008.CrossRefGoogle Scholar
Cahill, D. G., Watson, S. K., and Pohl, R. O., “Lower limit to the thermal conductivity of disordered crystals,” Phys. Rev. B, vol. 46, no. 10, pp. 61316140, 1992.CrossRefGoogle ScholarPubMed