Improved Thermoelectric Properties of Se-Doped n-Type PbTe1−xSex (0 ≤ x ≤ 1)
Enhancement of the thermoelectric figure of merit is of prime importance for any thermoelectric material. Lead telluride has received attention as a potential thermoelectric material. In this work, the effect of Se substitution has been systematically investigated in PbTe1−xSex. The thermoelectric properties of synthesized alloys were measured in the temperature range of 300 K to 873 K. For the particular composition of x = 0.5, α was highest at ~292 μV/K, while k was lowest at ~0.75 W/m-K, resulting in the highest dimensionless figure of merit of ZT ≈ 0.95 at 600 K. The increase in thermopower for x = 0.5 can be attributed to the high distortion in the crystal lattice which leads to the formation of defect states. These defect states scatter the majority charge carriers, leading to high thermopower and high electrical resistivity. The dramatic reduction of the thermal conductivity for x = 0.5 can be attributed to phonon scattering by defect states.
KeywordsThermoelectric materials defects thermal conductivity
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- 1.D. Rowe, eds., Thermoelectrics Handbook: Macro to Nano (Boca Raton: CRC Press, 2006).Google Scholar
- 3.T.M. Tritt, ed., Semiconductors and Semimetals, vol. 69–71 (San Diego: Academic Press, 2001).Google Scholar
- 5.G.S. Nolas, J. Sharp, and H. Goldsmid, Thermoelectrics: Basic Principles and New Materials Developments (New York: Springer, 2001).Google Scholar
- 10.S.N. Girard, J. He, X. Zhou, D. Shoemaker, C.M. Jaworski, C. Uher, V.P. Dravid, J.P. Heremans, and M.G. Kanatzidis, J. Am. Chem. Soc. 133, 16588 (2011).Google Scholar
- 11.C.M. Jaworski, B. Wiendlocha, V. Jovovic, and Joseph P. Heremans, Energy Environ. Sci. 4, 4155 (2011).Google Scholar
- 12.J. Androulakis, I. Todorov, J. He, D.Y. Chung, V. Dravid, and M.G. Kanatzidis, J. Am. Chem. Soc. 133, 10920 (2011).Google Scholar
- 17.J.R. Sootsman, D.Y. Chung, and M.G. Kanatzidis, Angew. Chem. Int. Ed. 48, 8616 (2009).Google Scholar
- 19.Y.I. Ravich, B.A. Efimova, and I.A. Smirnov, Semiconducting Lead Chalcogenides (Plenum, 1970).Google Scholar
- 20.G.T. Alekseeva, B. Efimova, L.M. Ostrovsk, O.S. Serebrya, and M. Tsypin, Sov. Phys. Semicond. 4, 1122 (1971).Google Scholar
- 22.N.F. Mott and H. Jones, The Theory of the Properties of Metals and Alloys (New York: Dover, 1958).Google Scholar
- 23.N.M. Constantine (Mechanical Engineering Dissertations, 2008).Google Scholar
- 24.A. Ioffe, Semiconductor Thermoelements and Thermoelectric Cooling (London: Infosearch, 1957).Google Scholar