The rapid enhancement of the thermoelectric (TE) figure-of-merit (zT) in the past decade has opened opportunities for developing and transitioning solid state waste heat recovery systems. Here, a segmented TE device architecture is demonstrated in conjunction with heterogeneous material integration that results in high unicouple-level conversion efficiency of 12% under a temperature difference of 584 K. This breakthrough is the result of success in fabricating bismuth telluride/half-Heusler segmented TE unicouple modules using a “hot-to-cold” fabrication technique that provides significantly reduced electrical and thermal contact resistance. Extensive analytical and finite element modeling is conducted to provide an understanding of the nature of thermal transport and contributions arising from various thermal and physical parameters. Bismuth telluride/half-Heusler based segmented thermoelectric generators (TEGs) can provide higher practical temperature difference with optimum average zT across the whole operating range. These results will have immediate impact on the design and development of TEGs and in the general design of devices based upon heterostructures that take advantage of gradients in the figure of merit.
Bibliographical noteFunding Information:
W.L. and B.P. acknowledge the financial support from the DARPA MATRIX program (NETS). R.S. acknowledges the support from Office of Naval Research through the grant number N000141912461. A.N. acknowledges the financial support through Office of Naval Research through grant number N00014‐20‐1‐2602. H.Z. acknowledges the support from Army Research Office through grant number W911NF1620010. H.B.K. and S.P. acknowledge the financial support from the National Science Foundation through I/UCRC Program.
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- contact resistance
- conversion efficiency
- module fabrication
- thermoelectric modules