Publication: Melt-centrifuged (BI,SB)(2)TE-3: engineering microstructure toward high thermoelectric efficiency
Program
KU-Authors
KU Authors
Co-Authors
Pan, Yu
Grovogui, Jann A.
Witting, Ian T.
Hanus, Riley
Xu, Yaobin
Wu, Jinsong
Wu, Chao-Feng
Sun, Fu-Hua
Zhuang, Hua-Lu
Dong, Jin-Feng
Advisor
Publication Date
2018
Language
English
Type
Journal Article
Journal Title
Journal ISSN
Volume Title
Abstract
Microstructure engineering is an effective strategy to reduce lattice thermal conductivity (kappa(l)) and enhance the thermoelectric figure of merit (zT). Through a new process based on melt-centrifugation to squeeze out excess eutectic liquid, microstructure modulation is realized to manipulate the formation of dislocations and clean grain boundaries, resulting in a porous network with a platelet structure. In this way, phonon transport is strongly disrupted by a combination of porosity, pore surfaces/junctions, grain boundaries, and lattice dislocations. These collectively result in a approximate to 60% reduction of kappa(l) compared to zone melted ingot, while the charge carriers remain relatively mobile across the liquid-fused grains. This porous material displays a zT value of 1.2, which is higher than fully dense conventional zone melted ingots and hot pressed (Bi,Sb)(2)Te-3 alloys. A segmented leg of melt-centrifuged Bi0.5Sb1.5Te3 and Bi0.3Sb1.7Te3 could produce a high device ZT exceeding 1.0 over the whole temperature range of 323-523 K and an efficiency up to 9%. The present work demonstrates a method for synthesizing high-efficiency porous thermoelectric materials through an unconventional melt-centrifugation technique.
Description
Source:
Advanced Materials
Publisher:
Wiley-V C H Verlag Gmbh
Keywords:
Subject
Chemistry, multidisciplinary, Chemistry, physical, Nanoscience, Nanotechnology, Materials science, multidisciplinary, Physics, applied, Physics, condensed matter