Enhanced thermoelectric performance in GaxCo4Sb12.3-yTey skutterudites via suppressing bipolar effects for commercial application

Jing Jiang; Rui Zhang; Chengcheng Yang; Yi Niu; Ting Zhou; Yan Pan; Chao Wang

Journal of Materiomics (Jun 2020)

Enhanced thermoelectric performance in GaxCo4Sb12.3-yTey skutterudites via suppressing bipolar effects for commercial application

Jing Jiang,
Rui Zhang,
Chengcheng Yang,
Yi Niu,
Ting Zhou,
Yan Pan,
Chao Wang

Affiliations

Jing Jiang: Clean Energy Materials and Engineering Center, State Key Laboratory of Electronic Thin Film and Integrated Device, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
Rui Zhang: Clean Energy Materials and Engineering Center, State Key Laboratory of Electronic Thin Film and Integrated Device, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
Chengcheng Yang: Clean Energy Materials and Engineering Center, State Key Laboratory of Electronic Thin Film and Integrated Device, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
Yi Niu: Clean Energy Materials and Engineering Center, State Key Laboratory of Electronic Thin Film and Integrated Device, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
Ting Zhou: Clean Energy Materials and Engineering Center, State Key Laboratory of Electronic Thin Film and Integrated Device, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
Yan Pan: Clean Energy Materials and Engineering Center, State Key Laboratory of Electronic Thin Film and Integrated Device, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
Chao Wang: Corresponding author.; Clean Energy Materials and Engineering Center, State Key Laboratory of Electronic Thin Film and Integrated Device, School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China

Journal volume & issue: Vol. 6, no. 2
pp. 240 – 247

Abstract

Read online

The n-type filled and doped skutterudites GaxCo4Sb12.3 and Ga0.2Co4Sb11.3Te composites with the well-distributed GaSb nanoinclusions are synthesized through the manipulating of metastable Ga fillers and enrichment of Sb by an in-situ method with a proper annealing procedure. Ga atoms can fill the icosahedron cages of skutterudite at high temperature, but at low temperature, they are driven out from the lattice voids and form the second phase of GaSb at grain boundaries. The presence of GaSb second phases reduces the thermal conductivity effectively. Te doping leads to a significant increase in carrier concentration of Ga0.2Co4Sb11.3Te, thus largely suppresses the bipolar effect of GaxCo4Sb12.3, resulting in a great enhancement in power factor. Moreover, Te doping induces mass and strain fluctuation, which decreases the lattice thermal conductivity further. Consequently, the maximum ZT is increased from 0.56 for Ga0.2Co4Sb12.3 at 573 K to 1.48 for Ga0.2Co4Sb11.3Te at 873 K, which is advantageous to improve the thermoelectric conversion efficiency for commercial application. Keywords: Thermoelectric, Skutterudite, Second phase, Bipolar effect

Published in Journal of Materiomics

ISSN: 2352-8478 (Print); 2352-8486 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials
Website: https://www.sciencedirect.com/journal/journal-of-materiomics

About the journal