Anomalously Large Seebeck Coefficient of CuFeS2 Derives from Large Asymmetry in the Energy Dependence of Carrier Relaxation Time

Hongyao Xie, Xianli Su, Trevor P. Bailey, Cheng Zhang, Wei Liu, Ctirad Uher, Xinfeng Tang*, Mercouri G. Kanatzidis

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

17 Scopus citations

Abstract

The Seebeck effect in a material originates from the distribution of asymmetry in the electron transport under a temperature gradient, which has contributions from the energy-dependent electronic density-of-states and carrier mobility. However, because the energy dependence of common electron scattering mechanisms is weak, the mobility-driven Seebeck coefficient has long been ignored in most thermoelectric materials, and the energy asymmetry of the density-of-states has been considered the dominant contribution. In this work, we describe a hopping transport behavior observed in CuFeS2, and a large carrier Hall mobility gradient of dμH/dT that creates an unusually large energy-dependent mobility contribution to the Seebeck coefficient. This work offers several ideas regarding the mobility-driven Seebeck effect and its potential utilization in the design of thermoelectric materials.

Original languageEnglish (US)
JournalACS Applied Materials and Interfaces
DOIs
StateAccepted/In press - 2020

Funding

The work at Northwestern University was supported by a grant from the U.S. Department of Energy, Office of Science, and Office of Basic Energy Sciences under award number DE-SC0014520 (material synthesis and structural characterization). X.T. wishes to acknowledge support from the National Key Research and Development Program of China (2019YFA0704902), the Natural Science Foundation of China (grant nos. 51972256, 51872219, 51632006, and 51521001), and the 111 Project of China (grant no. B07040).

ASJC Scopus subject areas

  • General Materials Science

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