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

Hong, Min and Chasapis, Thomas C. and Chen, Zhi-Gang 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

Abstract

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.


Statistics for USQ ePrint 35476
Statistics for this ePrint Item
Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to Published version, in accordance with the copyright policy of the publisher.
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - No Department
Date Deposited: 21 Jan 2019 03:14
Last Modified: 01 Feb 2019 02:56
Uncontrolled Keywords: Bi2Te3−xSex, nanostructuring, thermoelectric, synergistic carrier scatterings, wide-frequency phonon scatterings
Fields of Research : 03 Chemical Sciences > 0302 Inorganic Chemistry > 030206 Solid State Chemistry
10 Technology > 1007 Nanotechnology > 100708 Nanomaterials
02 Physical Sciences > 0204 Condensed Matter Physics > 020403 Condensed Matter Modelling and Density Functional Theory
09 Engineering > 0912 Materials Engineering > 091205 Functional Materials
Identification Number or DOI: 10.1021/acsnano.6b01156
URI: http://eprints.usq.edu.au/id/eprint/35476

Actions (login required)

View Item Archive Repository Staff Only