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Development of a Bi2Te3-based thermoelectric generator with high-aspect ratio, free-standing legs

Published online by Cambridge University Press:  13 February 2012

D.E. Wesolowski*
Affiliation:
Sandia National Laboratories, Albuquerque, New Mexico 87185
R.S. Goeke
Affiliation:
Sandia National Laboratories, Albuquerque, New Mexico 87185
A.M. Morales
Affiliation:
Sandia National Laboratories, Albuquerque, New Mexico 87185
S.H. Goods
Affiliation:
Sandia National Laboratories, Albuquerque, New Mexico 87185
P.A. Sharma
Affiliation:
Sandia National Laboratories, Albuquerque, New Mexico 87185
M.P. Saavedra
Affiliation:
Sandia National Laboratories, Albuquerque, New Mexico 87185
K.R. Reyes-Gil
Affiliation:
Sandia National Laboratories, Albuquerque, New Mexico 87185
W.C.G. Neel
Affiliation:
Sandia National Laboratories, Albuquerque, New Mexico 87185
N.Y.C. Yang
Affiliation:
Sandia National Laboratories, Albuquerque, New Mexico 87185
C.A. Apblett
Affiliation:
Sandia National Laboratories, Albuquerque, New Mexico 87185
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

A bismuth telluride alloy-based thermoelectric generator with high-aspect ratio, free-standing legs was fabricated. Such legs are desirable for efficient generator performance from low-grade heat sources but are difficult to assemble because they are fragile and difficult to handle and position. Plunge and wire electro-discharge machining (EDM) were used to produce 150 μm × 300 μm legs, approximately 6-mm long, with high fidelity. Removal of recast material from EDM was necessary for good adhesion of metallization, but sputter etching was found to deteriorate the mechanical strength of the contacts. A wet chemical cleaning process was developed instead that resulted in good adhesion under test conditions. Au was preferred for designs where interconnects could be patterned directly on the module. Module figure of merit (ZT) was 0.72, close to the 0.85 value expected from bulk material property measurements. Impedance spectroscopy and the Harman technique were shown to significantly underestimate module ZT in the present test configuration. Shear and fatigue testing were performed on arrays of high-aspect ratio legs. Legs survived over 104 cycles of shear loading at 90% of the load to failure.

Type
Articles
Copyright
Copyright © Materials Research Society 2012

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References

REFERENCES

1.Snyder, G.J. and Toberer, E.S.: Complex thermoelectric materials. Nat. Mater. 7, 105 (2008).CrossRefGoogle ScholarPubMed
2.Paradiso, J.A. and Starner, T.: Energy scavenging for mobile and wireless electronics. IEEE Pervasive Comput. 4(1), 18 (2005).CrossRefGoogle Scholar
3.Vasilevskiy, D., Kukhar, N., Turenne, S., and Masut, R.A.: Hot extruded (Bi,Sb)2(Te,Se)3 alloys for advanced thermoelectric modules, in 5th European Conference on Thermoelectrics (ECT2007) (Odessa House of Scientists, Odessa, Ukraine, September 10–12, 2007).Google Scholar
4.Yang, N. and Morales, A.: Metallurgy, thermal stability, and failure mode of the commercial Bi-Te-based thermoelectric modules. Report SAND2009-0758 (Sandia National Laboratories, Albuquerque, NM, February 2009).CrossRefGoogle Scholar
5.Anatychuk, L.I. and Pustovalov, A.A.: Thermoelectric microgenerators with isotope heat sources, in Thermoelectrics Handbook Macro to Nano, edited by Rowe, D.M. (CRC Press, Boca Raton, FL, 2006).Google Scholar
6.Snyder, G.J., Borshchevsky, A., Zoltan, A., Caillat, T., Fleurial, J.P., Nesmith, B., Mondt, J., McBirney, T., Allen, D., Bass, J.C., Ghamaty, S., Elsner, N., and Anatychuk, L.: Testing of milliwatt power source components, in 21st International Conference on Thermoelectrics (ICT ’02), Long Beach, CA, August 25–29, 2002, pp. 463470.Google Scholar
7.Keys, J.D. and Sutton, H.M.: Diffusion and solid solubility of gold in single-crystal bismuth telluride. J. Appl. Phys. 34, 1830 (1963).CrossRefGoogle Scholar
8.Yoo, H-J., Lee, C-H., Park, Y-H., and Park, I-M.: Au as an acceptor in thermoelectric bismuth antimony telluride alloys prepared by mechanical alloying process. Mater. Sci. Forum 475479, 1759 (2005).CrossRefGoogle Scholar
9.Goldsmid, H.J.: Conversion efficiency and figure-of-merit, in CRC Handbook of Thermoelectrics, edited by Rowe, D.M. (CRC Press, Boca Raton, FL, 1995).Google Scholar
10.Hiller, N., Allen, D., Elsner, N., Bass, J.C., and Moore, J.P.: Outgassing and vaporization considerations in milliwatt generators designed for 20-year missions. STAIF 2002. AIP Conf. Proc. 608, 989 (2002).CrossRefGoogle Scholar
11.Purdy, D.L.: Nuclear batteries for implantable applications, in Batteries for Biomedical Implantable Devices, edited by Owens, B.B. (Plenum, New York, 1986), p. 285.CrossRefGoogle Scholar
12.Lin, W.P., Wesolowski, D.E., and Lee, C.C.: Barrier/bonding layers on bismuth telluride (Bi2Te3) for high temperature thermoelectric modules. J. Mater. Sci. Mater. Electron. (2011). DOI 10.1007/s10854-011-0306-0CrossRefGoogle Scholar
13.Whalen, S.A., Apblett, C.A., and Aselage, T.L.: Improving power density and efficiency of miniature radioisotopic thermoelectric generators. J. Power Sources 180(1), 657 (2008).CrossRefGoogle Scholar
14.Liao, C-N., Lee, C-H., and Chen, W-J.: Effect of interfacial compound formation on contact resistivity of soldered junctions between bismuth telluride-based thermoelements and copper. Electrochem. Solid-State Lett. 10(9), 23 (2007).CrossRefGoogle Scholar
15.Downey, A.D., Timm, E., Poudeu, P., Kanatzidis, M.G., Shock, H., and Hogan, T.P.: Application of transmission line theory for modeling of a thermoelectric module in multiple configurations for AC electrical measurements, in Materials and Technologies for Direct Thermal-to-Electric Energy Conversion, edited by Yang, J., Hogan, T.P., Funahashi, R., and Nolas, G.S. (Mater. Res. Soc. Symp. Proc. 886, Warrendale, PA, 2006), 0886-F10-07, p. 425.Google Scholar
16.Downey, A.D., Hogan, T.P., and Cook, B.: Characterization of thermoelectric elements and devices by impedance spectroscopy. Rev. Sci. Instrum. 78(9), 093904 (2007).CrossRefGoogle ScholarPubMed
17.Gustafsson, S.E.: Transient plane source techniques for thermal conductivity and thermal diffusivity measurements of solid materials. Rev. Sci. Instrum. 62, 797 (1991).CrossRefGoogle Scholar
18.Iwasaki, H., Koyano, M., and Hori, H.: Evaluation of the figure of merit on thermoelectric materials by Harman method. Jpn. J. Appl. Phys. 41, 6606 (2002).CrossRefGoogle Scholar