Comparison of skutterudites and advanced thin-film B/sub 4/C/B/sub 9/C and Si/SiGe materials in advanced thermoelectric energy recovery systems

Various advanced thermoelectric (TE) materials have properties that are inherently advantageous for particular TE energy recovery applications. Skutterudites, 0- and 1-dimensional quantum-well materials, and thin-film superlattice materials are providing enhanced opportunities for advanced TE energy recovery. This work demonstrates that early skutterudites materials in dual-material, segmented couple designs may be best suited for higher temperature applications associated with spacecraft power systems and very high temperature exhaust waste heat recovery in heavy vehicles. Early thin-film BxC/Si-SiGe materials appear to be well suited for mid-temperature ranges in exhaust waste heat recovery in heavy-duty and passenger vehicles. Potential power generation at specific exhaust temperature levels and for various heat exchanger performance levels are presented showing the current design sensitivities using each of these TE material sets. Mathematical relationships inherently linking optimum TE design variables and the thermal systems design (i.e., heat exchangers) are also investigated.