Boosting the Thermoelectric Performance of (Na,K)-Codoped Polycrystalline SnSe by Synergistic Tailoring of the Band Structure and Atomic-Scale Defect Phonon Scattering

Zhen-Hua Ge; Dongsheng Song; Xiaoyu Chong; Fengshan Zheng; Lei Jin; Xin Qian; Lei Zheng; Rafal E Dunin-Borkowski; Peng Qin; Jing Feng; Li-Dong Zhao

doi:10.1021/jacs.7b05339

Boosting the Thermoelectric Performance of (Na,K)-Codoped Polycrystalline SnSe by Synergistic Tailoring of the Band Structure and Atomic-Scale Defect Phonon Scattering

J Am Chem Soc. 2017 Jul 19;139(28):9714-9720. doi: 10.1021/jacs.7b05339. Epub 2017 Jul 5.

Authors

Zhen-Hua Ge¹, Dongsheng Song², Xiaoyu Chong^{1

3}, Fengshan Zheng⁴, Lei Jin⁴, Xin Qian⁵, Lei Zheng⁵, Rafal E Dunin-Borkowski⁴, Peng Qin¹, Jing Feng¹, Li-Dong Zhao⁵

Affiliations

¹ Faculty of Materials Science and Engineering, Kunming University of Science and Technology , Kunming 650093, China.
² National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, Tsinghua University , Beijing 100084, China.
³ Department of Materials Science and Engineering, The Pennsylvania State University , University Park, Pennsylvania 16802, United States.
⁴ Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich , 52425 Jülich, Germany.
⁵ School of Materials Science and Engineering, Beihang University , Beijing 100191, China.

PMID: 28635266
DOI: 10.1021/jacs.7b05339

Abstract

We report the high thermoelectric performance of p-type polycrystalline SnSe obtained by the synergistic tailoring of band structures and atomic-scale defect phonon scattering through (Na,K)-codoping. The energy offsets of multiple valence bands in SnSe are decreased after Na doping and further reduced by (Na,K)-codoping, resulting in an enhancement in the Seebeck coefficient and an increase in the power factor to 492 μW m^-1 K^-2. The lattice thermal conductivity of polycrystalline SnSe is decreased by the introduction of effective phonon scattering centers, such as point defects and antiphase boundaries. The lattice thermal conductivity of the material is reduced to values as low as 0.29 W m^-1 K^-1 at 773 K, whereas ZT is increased from 0.3 for 1% Na-doped SnSe to 1.2 for 1% (Na,K)-codoped SnSe.

Publication types

Research Support, Non-U.S. Gov't