n-type Bi2Te3-xSex nanoplates with enhanced thermoelectric efficiency driven by wide-frequency phonon scatterings and synergistic carrier scatterings

Hong, Min ORCID: https://orcid.org/0000-0002-6469-9194 and Chasapis, Thomas C. and Chen, Zhi Gang ORCID: https://orcid.org/0000-0002-9309-7993 and Yang, Lei and Kanatzidis, Mercouri G. and Snyder, G. Jeffrey and Zou, Jin (2016) n-type Bi2Te3-xSex nanoplates with enhanced thermoelectric efficiency driven by wide-frequency phonon scatterings and synergistic carrier scatterings. ACS Nano, 10 (4). pp. 4719-4727. ISSN 1936-0851


Driven by the prospective applications of thermoelectric materials, massive efforts have been dedicated to enhancing the conversion efficiency. The latter is governed by the figure of merit (ZT), which is proportional to the power factor (S2σ) and inversely proportional to the thermal conductivity (κ). Here, we demonstrate the synthesis of high-quality ternary Bi2Te3-xSex nanoplates using a microwave-assisted surfactant-free solvothermal method. The obtained n-type Bi2Te2.7Se0.3 nanostructures exhibit a high ZT of 1.23 at 480 K measured from the corresponding sintered pellets, in which a remarkably low κ and a shift of peak S2σ to high temperature are observed. By detailed electron microscopy investigations, coupled with theoretical analysis on phonon transports, we propose that the achieved κ reduction is attributed to the strong wide-frequency phonon scatterings. The shifting of peak S2σ to high temperature is due to the weakened temperature dependent transport properties governed by the synergistic carrier scatterings and the suppressed bipolar effects by enlarging the band gap.

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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty/School / Institute/Centre: No Faculty
Faculty/School / Institute/Centre: No Faculty
Date Deposited: 21 Jun 2017 02:15
Last Modified: 21 Jun 2017 02:15
Uncontrolled Keywords: Bi2Te3-xSex; nanostructuring; synergistic carrier scatterings; thermoelectric; wide-frequency phonon scatterings; Carrier scattering; Nano-structuring; Prospective applications; Solvothermal method; Temperature dependent; Thermo-Electric materials; Thermoelectric efficiency; Thermodynamics;
Fields of Research (2008): 09 Engineering > 0912 Materials Engineering > 091299 Materials Engineering not elsewhere classified
Fields of Research (2020): 40 ENGINEERING > 4016 Materials engineering > 401699 Materials engineering not elsewhere classified
Socio-Economic Objectives (2008): E Expanding Knowledge > 97 Expanding Knowledge > 970109 Expanding Knowledge in Engineering
Identification Number or DOI: https://doi.org/10.1021/acsnano.6b01156
URI: http://eprints.usq.edu.au/id/eprint/31669

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