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Anisotropic layered Bi 2 Te 3 -In 2 Te 3 composites: control of interface density for tuning of thermoelectric properties.

Authors :
Liu D
Li X
Borlido PM
Botti S
Schmechel R
Rettenmayr M
Source :
Scientific reports [Sci Rep] 2017 Mar 08; Vol. 7, pp. 43611. Date of Electronic Publication: 2017 Mar 08.
Publication Year :
2017

Abstract

Layered (Bi <subscript>1-x</subscript> In <subscript>x</subscript> ) <subscript>2</subscript> Te <subscript>3</subscript> -In <subscript>2</subscript> Te <subscript>3</subscript> (x = 0.075) composites of pronounced anisotropy in structure and thermoelectric properties were produced by zone melting and subsequent coherent precipitation of In <subscript>2</subscript> Te <subscript>3</subscript> from a (Bi <subscript>1-x</subscript> In <subscript>x</subscript> ) <subscript>2</subscript> Te <subscript>3</subscript> (x > 0.075) matrix. Employing solid state phase transformation, the Bi <subscript>2</subscript> Te <subscript>3</subscript> /In <subscript>2</subscript> Te <subscript>3</subscript> interface density was tuned by modifying the driving force for In <subscript>2</subscript> Te <subscript>3</subscript> precipitation. The structure-property relationship in this strongly anisotropic material is characterized thoroughly and systematically for the first time. Unexpectedly, with increasing Bi <subscript>2</subscript> Te <subscript>3</subscript> /In <subscript>2</subscript> Te <subscript>3</subscript> interface density, an increase in electrical conductivity and a decrease in the absolute Seebeck coefficient were found. This is likely to be due to electron accumulation layers at the Bi <subscript>2</subscript> Te <subscript>3</subscript> /In <subscript>2</subscript> Te <subscript>3</subscript> interfaces and the interplay of bipolar transport in Bi <subscript>2</subscript> Te <subscript>3</subscript> . Significantly improved thermoelectric properties of Bi <subscript>2</subscript> Te <subscript>3</subscript> -In <subscript>2</subscript> Te <subscript>3</subscript> composites as compared to the single phase (Bi <subscript>1-x</subscript> In <subscript>x</subscript> ) <subscript>2</subscript> Te <subscript>3</subscript> solid solution are obtained.

Details

Language :
English
ISSN :
2045-2322
Volume :
7
Database :
MEDLINE
Journal :
Scientific reports
Publication Type :
Academic Journal
Accession number :
28272541
Full Text :
https://doi.org/10.1038/srep43611