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

Hong, Min, Chasapis, Thomas C., Chen, Zhi-Gang, Yang, Lei, Kanatzidis, Mercouri G., 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: 4719-4727. doi:10.1021/acsnano.6b01156


Author Hong, Min
Chasapis, Thomas C.
Chen, Zhi-Gang
Yang, Lei
Kanatzidis, Mercouri G.
Snyder, G. Jeffrey
Zou, Jin
Title n-Type Bi2Te3-xSex nanoplates with enhanced thermoelectric efficiency driven by wide-frequency phonon scatterings and synergistic carrier scatterings
Formatted title
n-Type Bi2Te3-xSex nanoplates with enhanced thermoelectric efficiency driven by wide-frequency phonon scatterings and synergistic carrier scatterings
Journal name ACS Nano   Check publisher's open access policy
ISSN 1936-086X
1936-0851
Publication date 2016-04-26
Year available 2016
Sub-type Article (original research)
DOI 10.1021/acsnano.6b01156
Open Access Status Not Open Access
Volume 10
Issue 4
Start page 4719
End page 4727
Total pages 9
Place of publication Washington, DC United States
Publisher American Chemical Society
Language eng
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 (S-2 sigma) and inversely proportional to the thermal conductivity (kappa). 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 kappa and a shift of peak S-2 sigma to high temperature are observed. By detailed electron microscopy investigations, coupled with theoretical analysis on phonon transports, we propose that the achieved kappa reduction is attributed to the strong wide-frequency phonon scatterings. The shifting of peak S-2 sigma 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.
Formatted 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.
Keyword Bi2Te3-xSex
Nanostructuring
Thermoelectric
Synergistic carrier scatterings
Wide-frequency phonon scatterings
Q-Index Code C1
Q-Index Status Provisional Code
Grant ID DE-SC0001299
DE-SC0014520
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Mechanical & Mining Engineering Publications
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