Structure and Thermoelectric Properties of Te- and Ge-Doped Skutterudites CoSb2.875−x Ge0.125Te x
Source: Journal of Electronic Materials, Volume 40, Number 5, May 2011 , pp. 1286-1291(6)
Abstract:n-Type CoSb2.875−x Ge0.125Te x (x = 0.125 to 0.275) compounds with different Te contents have been synthesized by a melt-quench-anneal-spark plasma sintering method, and the effects of Te content on the structure and thermoelectric properties have been investigated. The results show that all specimens exhibited n-type conduction characteristics. The solubility limit of Te in CoSb2.875−x Ge0.125Te x is found to be x = 0.25. The solubility of Te in CoSb3 is increased through charge compensation of the element Ge. The room-temperature carrier concentration N p of CoSb2.875−x Ge0.125Te x skutterudites increases with increasing Te content, and the compounds possess high power factors. The maximum power factor of 3.89 × 10−3 W m−1 K−2 was obtained at 720 K for the CoSb2.625Ge0.125Te0.25 compound. The thermal conductivity decreases dramatically with increasing Te content due to strong point defect scattering. The maximum value of the thermoelectric figure of merit ZT = 1.03 was obtained at 800 K for CoSb2.625Ge0.125Te0.25, benefiting from a lower thermal conductivity and a higher power factor. The figure of merit is competitive with values reported for single-filled skutterudites.
Document Type: Research article
Affiliations: 1: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, China 2: State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, 430070, China, Email: email@example.com 3: Department of Physics, University of Michigan, Ann Arbor, MI, 48109, USA
Publication date: 2011-05-01