ICAMS / Interdisciplinary Centre for Advanced Materials Simulation


Band‐structure theory in the search for new thermoelectric materials

Date: 23.11.2010
Place: Materials Discovery by Scale‐Bridging High‐Throughput Experimentation and Modelling Workshop, Ruhr-Universität Bochum, Bochum, Germany

Georg Madsen

Thermoelectric materials have applications in both Peltier‐cooling and in converting waste heat to electrical energy. Due to the discovery of new materials the area has received much attention the past decade.

The performance of a thermoelectric material is measured by the dimensionless figure of merit, zT=(σ T/κ) S2, where S is the Seebeck coefficient and σ and κ are the electronic and thermal conductivities respectively. zT quantifies the performance of a thermoelectric and one must therefore maximize the power factor, Sσ, and minimize κ. S, σ and κ are coupled and depend strongly on the detailed atomic and electronic structure, which makes the task of finding new compounds with large values of zT difficult.

Based on a case study of CsBi4Te6 it will be shown how electronic structure calculations can be used to rationalize the behavior of known materials. In this process some "fingerprints", which characterize good performance, are identified. These observations are used to construct a screening of the inorganic crystal structure database for potential thermoelectric materials. I will show how this resulted in the discovery of two new materials: FeSb2 and LiZnSb.

[1] L. Lykke, B. B. Iversen, and G. K. H. Madsen, Phys. Rev. B 73, 195121 (2006).
[2] G. K. H. Madsen, J. Am. Chem. Soc. 128, 12140 (2006).
[3] A. Bentien, S. Johnsen, G. K. H. Madsen, B. B. Iversen, and F. Steglich, Europhys. Lett. 80, 17008 (2007).

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