Thermoelectric Performance of Yb-Doped Ba8Ni0.1Zn0.54Ga13.8Ge31.56 Type-I Clathrate Synthesized by High-Pressure Technique

• Published in: Journal of electronic materials Vol. 46; no. 5; pp. 2860 - 2866
• Main Authors: Chen, Chen, Zhang, Long, Dong, Jianying, Xu, Bo
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.05.2017
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Electronics and Microelectronics; Instrumentation; Materials Science; Optical and Electronic Materials; Solid State Physics; high-pressure synthesis; thermoelectricity; Yb doping; Type I clathrate
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-016-5013-4

Type I clathrates are a promising thermoelectric (TE) material for waste heat recovery applications. However, the TE figure-of-merit of type I clathrates still needs further improvement. In this study, Yb-doped Ba 8− x Yb x Ni 0.1 Zn 0.54 Ga 13.8 Ge 31.56 (0 ≤  x  ≤ 0.5) type I clathrates were synthesized using a high-pressure technique. Energy dispersive spectrometry confirmed successful Yb doping. An increased Yb doping level reduces electrical resistivity and suppresses lattice thermal conductivity while keeping the Seebeck coefficient almost unchanged. TE figure-of-merit of Ba 7.7 Yb 0.3 Ni 0.1 Zn 0.54 Ga 13.8 Ge 31.56 type I clathrate was improved by 15% (0.91) at the highest measured temperature (900 K) compared with a Yb-free sample.