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Seebeck coefficient of graded porous composites

Published online by Cambridge University Press:  17 May 2013

Roland H. Tarkhanyan*
Affiliation:
Institute for Advanced Materials, Physicochemical Processes, Nanotechnology & Microsystems, Department of Materials Science, NCSR “Demokritos”, Athens 15310, Greece; and Institute of Radiophysics & Electronics, NAS of Armenia, Ashtarak 0204, Armenia
Dimitris G. Niarchos
Affiliation:
Institute for Advanced Materials, Physicochemical Processes, Nanotechnology & Microsystems, Department of Materials Science, NCSR “Demokritos”, Athens 15310, Greece
*
a)Address all correspondence to this author. e-mail: [email protected], [email protected]
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Abstract

A physical model is developed for the enhancement of the Seebeck coefficient (S) in a porous thermoelectric material with inhomogeneous porosity. The pores are assumed to be hole and of spherical shape. We take into account the presence of trap centers situated at pore/medium interfaces and neglect changes in the carrier effective mass due to the band-bend. We show that the porosity always leads to an increase in the absolute value of S. A simple relation is derived for S in nondegenerate n-type semiconducting materials in the case when the main contribution in the carrier relaxation time at zero porosity is from the scattering on acoustic phonons. We have shown that the value of S does not depend on the orientation of the porosity gradient with respect to the direction of the temperature gradient. The relative growth of the Seebeck coefficient compared to its value in the bulk material of the same volume is examinated for different number of the pore groups with different characteristic sizes at various pore size distributions.

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Articles
Copyright
Copyright © Materials Research Society 2013 

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References

REFERENCES

Dresselhaus, M.S., Chen, G., Tang, M.Y., Yang, R.G., Lee, H., Wang, D.Z., Ren, Z.F., Fleurial, J.P., and Gogna, P.: New directions for low-dimensional thermoelectric materials. Adv. Mater. 19, 10431052 (2007).CrossRefGoogle Scholar
Li, J.F., Liu, W.S., Zhao, L.D., and Zhou, M.: High-performance nanostructured thermoelectric materials. Nature Asia Mater. 2, 152158 (2010).CrossRefGoogle Scholar
Vashaee, D. and Shakouri, A.: Improved thermoelectric power factor in metal-based superlattices. Phys. Rev. Lett. 92, 106103 (2004).CrossRefGoogle ScholarPubMed
Heremans, J.P., Thrush, C.M., and Moreli, D.T.: Thermopower enhancement in lead telluride nanostructures. Phys. Rev. B 70, 115334 (2004).CrossRefGoogle Scholar
Faleev, S.V. and Leonard, F.: Theory of enhancement of thermoelectric properties of materials with nanoinclusions. Phys. Rev. B 77, 214304 (2008).CrossRefGoogle Scholar
Lee, H., Vashaee, D., Wang, D.Z., Dresselhaus, M.S., Ren, Z.F., and Chen, G.: Effects of nanoscale porosity on thermoelectric properties of SiGe. J. Appl. Phys. 107, 094308 (2010).CrossRefGoogle Scholar
Russel, H.W.: Principles of heat flow in porous insulators. J. Am. Ceram. Soc. 18, 15 (1935).CrossRefGoogle Scholar
Lee, J.H., Galli, G.A., and Grossman, J.C.: Nanoporous Si as an efficient thermoelectric material. Nano Lett. 8, 3750 (2008).CrossRefGoogle ScholarPubMed
Sugawara, A. and Yoshizawa, Y.: An investigation on the thermal conductivity of porous materials and its application to porous Rook. Aust. J. Phys. 14, 469480 (1961).CrossRefGoogle Scholar
Wang, M., Wang, J., Pan, N., and Chen, S.: Mesoscopic predictions of the effective thermal conductivity for microscale random porous media. Phys. Rev. E 75, 036702 (2007).CrossRefGoogle ScholarPubMed
Bergman, D.J. and Levy, O.: Thermoelectric properties of a composite medium. J. Appl. Phys. 70, 6821 (1991).CrossRefGoogle Scholar
Fel, L.G., Strelniker, Y.M., and Bergman, D.J.: Enhancement of power factor in a thermoelectric composite with a periodic microstructure, in Proceedings MRS Spring Meeting, San Francisco, April 2000. Vol. 626, Z6.5.Google Scholar
Landauer, R.: Electrical Transport and Optical Properties of Inhomogeneous Media, American Institute of Physics, New York, 1978. pp. 245,Google Scholar
Song, D.W., Shen, W.N., Dunn, B., Moore, C.D., Goorsky, M.S., Radetic, T., Gronsky, R., and Chen, G.: Thermal conductivity of nanoporous bismuth thin films. Appl. Phys. Lett. 84, 18831885 (2004).CrossRefGoogle Scholar
Yang, R.G., Chen, G., and Dresselhaus, M.S.: Thermal conductivity of core-shell and tubular nanowires. Nano Lett. 5, 11111115 (2005).CrossRefGoogle ScholarPubMed
Callaway, J.: Model for lattice thermal conductivity at low temperature. Phys. Rev. 113, 10461051 (1959).CrossRefGoogle Scholar
Holland, M.G.: Analysis of lattice thermal conductivity. Phys. Rev. 132, 24612471 (1963).CrossRefGoogle Scholar
Majumdar, A.: Microscale heat conduction in dielectric thin films. J. Heat Transfer 115, 716 (1993).CrossRefGoogle Scholar
Popescu, A., Woods, L.M., Martin, J., and Nolas, G.S.: Model of transport properties of thermoelectric nanocomposite materials. Phys. Rev. B 79, 205302 (2009).CrossRefGoogle Scholar
Tarkhanyan, R.H. and Niarchos, D.G.: Reduction in lattice thermal conductivity of porous materials due to inhomogeneous porosity. Int. J. Thermal Sci. 67, 107112 (2013).CrossRefGoogle Scholar
Ziman, J.M.: Electrons and Phonons. (Oxford University Press, Oxford, 1960).Google Scholar
Ansel'm, A.I.: Introduction to Semiconductor Theory. (Mir, Moscou, Prentice-Hall, Englewood Cilffs, New Jersey, 1981).Google Scholar
Kittel, C.: Introduction to Solid State Physics. (Wiley, New York, 1971).Google Scholar
Lundstrom, M.: Fundamentals of Carrier Transport, 2nd ed. (Cambridge University Press, Cambridge, 2000).CrossRefGoogle Scholar
Chen, G.: Nanoscale Energy Transport and Conversion. (Oxford University Press, New York, 2005).CrossRefGoogle Scholar
Yu, P.Y. and Cardona, M.: Fundamentals of Semiconductors, 3rd ed. (Springer, Berlin, 2003).Google Scholar
Touloukian, Y.S., Powell, R.W., Ho, C.Y., and Klemens, P.G.: Thermophysical Properties of Matter, Vol. 1 (IFI/Plenum, New York, 1970), p. 339.Google Scholar
Landau, L.D. and Lifshitz, E.M.: Quantum Mechanics Nonrelativistic Theory, 3rd ed. (Nauka, Moscow, 1976).Google Scholar
Callen, H.B.: Thermodynamics. (Wiley & Sons, NewYork, 1960).Google Scholar
de Groot, S.R. and Mazur, P.: Non-equilibrium Thermodynamics. (North-Holland Com., Amsterdam, 1962).Google Scholar