TY - JOUR
T1 - Achieving zT > 2 in p-Type AgSbTe2− xSex Alloys via Exploring the Extra Light Valence Band and Introducing Dense Stacking Faults
AU - Hong, Min
AU - Chen, Zhi Gang
AU - Yang, Lei
AU - Liao, Zhi Ming
AU - Zou, Yi Chao
AU - Chen, Yan Hui
AU - Matsumura, Syo
AU - Zou, Jin
N1 - Funding Information:
This work is financially supported by the Australian Research Council. Z.G.C. thanks the USQ start-up grant and strategic research grant. Dr. M. Kudo is thanked for helping STEM experiments under the Progress 100 program to encourage the UQ-KU collaboration as well as the Nanotechnology Platform Project for advanced nanostructure characterization. The Australian Microscopy & Microanalysis Research Facility is acknowledged for providing characterization facilities. The Research Computing Centre of the University of Queensland is acknowledged for providing the computation clusters.
Publisher Copyright:
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2018/3/26
Y1 - 2018/3/26
N2 - Through simultaneously enhancing the power factor by engineering the extra light band and enhancing phonon scatterings by introducing a high density of stacking faults, a record figure-of-merit over 2.0 is achieved in p-type AgSbTe2− xSex alloys. Density functional theory calculations confirm the presence of the light valence band with large degeneracy in AgSbTe2, and that alloying with Se decreases the energy offset between the light valence band and the valence band maximum. Therefore, a significantly enhanced power factor is realized in p-type AgSbTe2− xSex alloys. In addition, transmission electron microscopy studies indicate the appearance of stacking faults and grain boundaries, which together with grain boundaries and point defects significantly strengthen phonon scatterings, leading to an ultralow thermal conductivity. The synergetic strategy of simultaneously enhancing power factor and strengthening phonon scattering developed in this study opens up a robust pathway to tailor thermoelectric performance.
AB - Through simultaneously enhancing the power factor by engineering the extra light band and enhancing phonon scatterings by introducing a high density of stacking faults, a record figure-of-merit over 2.0 is achieved in p-type AgSbTe2− xSex alloys. Density functional theory calculations confirm the presence of the light valence band with large degeneracy in AgSbTe2, and that alloying with Se decreases the energy offset between the light valence band and the valence band maximum. Therefore, a significantly enhanced power factor is realized in p-type AgSbTe2− xSex alloys. In addition, transmission electron microscopy studies indicate the appearance of stacking faults and grain boundaries, which together with grain boundaries and point defects significantly strengthen phonon scatterings, leading to an ultralow thermal conductivity. The synergetic strategy of simultaneously enhancing power factor and strengthening phonon scattering developed in this study opens up a robust pathway to tailor thermoelectric performance.
UR - http://www.scopus.com/inward/record.url?scp=85038089302&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85038089302&partnerID=8YFLogxK
U2 - 10.1002/aenm.201702333
DO - 10.1002/aenm.201702333
M3 - Article
AN - SCOPUS:85038089302
SN - 1614-6832
VL - 8
JO - Advanced Energy Materials
JF - Advanced Energy Materials
IS - 9
M1 - 1702333
ER -
