1. Structure inhomogeneities, shallow defects, and charge transport in the series of thermoelectric materials K2Bi8-xSbxSe13.
- Author
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Kyratsi, Theodora, Hatzikraniotis, Euripides, Paraskevopoulos, Konstantinos M., Malliakas, Christos D., Dyck, Jeff S., Uher, Ctirad, and Kanatzidis, Mercouri G.
- Subjects
THERMOELECTRIC materials ,BISMUTH-antimony alloys ,CHARGE transfer ,THERMAL properties of semiconductors ,ELECTRIC conductivity ,ELECTRONIC structure ,ELECTRON diffraction - Abstract
The charge transport properties of the low-dimensional thermoelectric materials K
2 Bi8-x Sbx Se13 (08-x Sbx Se13 was analyzed on the basis of the classical semiconductor theory and discussed in the context of recent band calculations. The results suggest that the K2 Bi8-x Sbx Se13 materials possess coexisting domains with semimetallic and semiconducting characters whose ratio is influenced by the value of x and by local defects. The extent and relative distribution of these domains control the charge transport properties. Electron diffraction experiments performed on samples of K2 Bi8-x Sbx Se13 with x=1.6 show evidence for such domains by indicating regions with long range ordering of K+ /Bi3+ atoms and regions with increased disorder. The semiconducting behavior is enhanced with increasing x (i.e., Sb/Bi ratio) in the composition through a decrease of the semimetallic fraction. [ABSTRACT FROM AUTHOR]- Published
- 2006
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