https://doi.org/10.1051/epjap/2022210237
Regular Article
The effects of alkaline-earth-metal-element doping on the thermoelectric properties of β-Zn4Sb3★
1
Center for Magnetic Materials and Devices, College of Physics and Electronic Engineering, Qujing Normal University, Qujing 655011, P.R. China
2 Key Laboratory for Advanced Functional and Low Dimensional Materials of Yunnan Higher Education Institute, Qujing Normal University, Qujing 655011, P.R. China
3 Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031, P.R. China
Received:
19
October
2021
Received in final form:
23
December
2021
Accepted:
3
February
2022
Published online: 4 April 2022
The effects of alkaline-earth metal elements Ca, Sr, and Ba on the electronic structure and thermoelectric properties of β-Zn4Sb3 were investigated by performing self-consistent ab initio electronic structure calculations within density functional theory and solving the Boltzmann transport equations within the relaxation time approximation. The results demonstrate that these alkaline-earth metal elements with s orbitals could introduce giant sharp resonant peaks in the electronic density of states (DOS) near the host valence band maximum in energy. And these deliberately engineered DOS peaks result in a sharp increase of the room-temperature Seebeck coefficient of β-Zn4Sb3 by a factor of nearly 8/9/19, respectively. Additionally, with the simultaneous increase of conductivity and decline of carrier thermal conductivity upon Ca/Sr/Ba doping, potentially, at least, 10/4/2-fold increase in optimizing power factor, and 14/12/8-fold increase in thermoelectric figure of merit of β-Zn4Sb3 at room temperature are achieved. And their corresponding optimal Fermi levels are all located near the host valence band maximum.
Supplementary material is available in electronic form at https://www.epjap.org/0.1051/epjap/2022210237
e-mail: liumianytu@163.com; xyqin@issp.ac.cn
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