Structure and Thermoelectric Properties of Bi2-xSbxTe₃ Nanowires Grown in Flexible Nanoporous Polycarbonate Templates

Anuja Datta; Abhijeet Sangle; Nick Hardingham; Charles Cooper; Max Kraan; David Ritchie; Vijay Narayan; Sohini Kar-Narayan

doi:10.3390/ma10050553

Structure and Thermoelectric Properties of Bi_2-xSb_xTe₃ Nanowires Grown in Flexible Nanoporous Polycarbonate Templates

Materials (Basel). 2017 May 19;10(5):553. doi: 10.3390/ma10050553.

Authors

Anuja Datta¹, Abhijeet Sangle², Nick Hardingham³, Charles Cooper⁴, Max Kraan⁵, David Ritchie⁶, Vijay Narayan⁷, Sohini Kar-Narayan⁸

Affiliations

¹ Department of Materials Science & Metallurgy, University of Cambridge, Cambridge CB3 0FS, UK. ad819@cam.ac.uk.
² Department of Materials Science & Metallurgy, University of Cambridge, Cambridge CB3 0FS, UK. as2174@cam.ac.uk.
³ Department of Materials Science & Metallurgy, University of Cambridge, Cambridge CB3 0FS, UK. nick.hardingham@gmail.com.
⁴ Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, UK. charles.f.cooper@gmail.com.
⁵ Department of Materials Science & Metallurgy, University of Cambridge, Cambridge CB3 0FS, UK. maxkraan1@gmail.com.
⁶ Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, UK. dar11@cam.ac.uk.
⁷ Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE, UK. vn237@cam.ac.uk.
⁸ Department of Materials Science & Metallurgy, University of Cambridge, Cambridge CB3 0FS, UK. sk568@cam.ac.uk.

Abstract

We report the room-temperature growth of vertically aligned ternary Bi_2-xSb_xTe₃ nanowires of diameter ~200 nm and length ~12 µm, within flexible track-etched nanoporous polycarbonate (PC) templates via a one-step electrodeposition process. Bi_2-xSb_xTe₃ nanowires with compositions spanning the entire range from pure Bi₂Te₃ (x = 0) to pure Sb₂Te₃ (x = 2) were systematically grown within the nanoporous channels of PC templates from a tartaric-nitric acid based electrolyte, at the end of which highly crystalline nanowires of uniform composition were obtained. Compositional analysis showed that the Sb concentration could be tuned by simply varying the electrolyte composition without any need for further annealing of the samples. Thermoelectric properties of the Bi_2-xSb_xTe₃ nanowires were measured using a standardized bespoke setup while they were still embedded within the flexible PC templates.

Keywords: Bi2−xSbxTe3; Seebeck coefficient; electrodeposition; nanowires; thermoelectric.