A TiAlCu Metallization for ‘n’ Type CoSbx Skutterudites with Improved Performance for High-Temperature Energy Harvesting Applications

• Published in: Journal of electronic materials 2017, Vol.46 (4), p.2419-2431
• Main Authors: Rao, Ashwin, Bosak, Gregg, Joshi, Binay, Keane, Jennifer, Nally, Luke, Peng, Adam, Perera, Susanthri, Waring, Alfred, Poudel, Bed
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Electronics and Microelectronics; Instrumentation; Materials Science; Optical and Electronic Materials; Solid State Physics
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-017-5306-2

The choice of the appropriate metallizing layer for high-temperature thermoelectric (TE) materials is a tricky task and poses varied challenges to researchers. In this work, a n type TiAl metallizing layer (90% Ti with 10% Al by weight with a copper foil) is proposed for a Yb 0.2 Co 4 Sb 12 skutterudite (SK) TE material coupled with a standard ‘ p type’ SK base of Nd 0.45 Ce 0.45 Fe 3.5 Co 0.5 Sb 12 with a 60:12:28% Fe:Ni:Cr metallizing layer. The n type and p type nanostructured SK powders are sintered at high temperatures and pressures in a DC hot press from which a TE device is assembled using diced, polished and property characterized TE legs (high figure of merit zT of 1.4 for n type and 1.2 for p type, respectively). The device is evaluated for functional degradation with repeated cycling to 500°C hot side (HS) and 50°C cold side (CS) temperatures in a specially designed high-vacuum test rig with key TE properties like peak power, open circuit voltage, and material internal resistance continuously recorded over each cycle. The device shows stable performance with