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An Extensive Theoretical Study of the Phonon Conductivity and Thermoelectric Properties of SiGe Alloys

Published online by Cambridge University Press:  16 February 2012

Iowerth O. Thomas  and
Gyaneshwar P. Srivastava
Iowerth O. Thomas
Affiliation:
School of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK
Gyaneshwar P. Srivastava
Affiliation:
School of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QL, UK
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Abstract

We present an extensive theoretical study of the phonon conductivity and thermoelectric properties of SiGe alloys. Phonon dispersion relations and group velocities – required for conductivity calculations – are obtained by employing the density-functional-perturbation scheme. The cubic anharmonic potential has been expressed by treating the Gr¨uneisen constant as a semi-adjustable mode-averaged parameter. Calculations are also performed, within the nearly-free-electron approximation, for the temperature variation of the Fermi energy, Seebeck coefficient, electrical conductivity, and electronic polar and bipolar contributions to thermal conductivity. Results are compared with experimental measurements for n-doped pressure-sintered Si0.754Ge0.246 alloy. Using these results, we compare our results for the thermoelectric figure-of-merit with previously reported results based on an empirical approach for phonon conductivity.

Keywords

thermal conductivitythermoelectricsemiconducting
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1404: Symposium W – Phonons in Nanomaterials–Theory, Experiments and Applications , 2012 , mrsf11-1404-w04-03
Copyright
Copyright © Materials Research Society 2012

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References

REFERENCES

[1] Minnich, A. J. et al. ., J. Energy Environ. Sci. 2, 466 (2009).Google Scholar
[2] Meddins, H. R. and Parrott, J. E., J. Phys. C: Solid State Phys. 9, 1263 (1976).Google Scholar
[3] McKelvey, J. P., Solid State and Semiconductor Physics (International Edition) (Harper & Row, New York, 1966).Google Scholar
[4] Blakemore, J. S., Solid State Physics (W. B. Saunders Company, Philadelphia, 1970), p. 262.Google Scholar
[5] Goldsmid, H. J., Introduction to Thermoelectricity (Springer-Verlag, Berlin, 2010).Google Scholar
[6] Drabble, J. R. and Goldsmid, H. J., Thermal Conduction in Semiconductors (Pergamon Press, Oxford, 1961).Google Scholar
[7] Srivastava, G. P., The Physics of Phonons (Adam Hilger, Bristol, 1990).Google Scholar
[8] Slack, G. A., Phys. Rev. B 126, 427 (1962).Google Scholar
[9] Madelung, O., Schulz, M. and Weiss, H. (eds.), Landolt-B¨ornstein Numerical Data and Functional Relationships in Science and Technology: Group III, Volume 17a (Springer-Verlag, Berlin, 1982).Google Scholar
[10] Monkhorst, H. J. and Pack, J.D., Phys. Rev. B 13, 5188 (1976).Google Scholar
[11] Baroni, S. et al. ., Rev. Mod. Phys. 73, 515 (2001).Google Scholar
[12] Gianozzi, P. et al. ., J. Phys. Cond. Mat. 21, 395502 (2009); the code and the pseudo-potentials Si.pz-vbc.UPF and Ge.pz-bhs.UPF used are available from http://www.quantum-espresso.org.Google Scholar
[13] AlShaikhi, A. and Srivastava, G. P., Phys. Rev. B 76, 195205 (2007).Google Scholar