Synergistic Manipulation of Interdependent Thermoelectric Parameters in SnTe-AgBiTe2 Alloys by Mn Doping

Zhe Guo; Gang Wu; Xiaojian Tan; Ruoyu Wang; Zipeng Yan; Qiang Zhang; Kun Song; Peng Sun; Haoyang Hu; Chen Cui; Guo-Qiang Liu; Jun Jiang

doi:10.1021/acsami.2c07548

Synergistic Manipulation of Interdependent Thermoelectric Parameters in SnTe-AgBiTe₂ Alloys by Mn Doping

ACS Appl Mater Interfaces. 2022 Jun 29;14(25):29032-29038. doi: 10.1021/acsami.2c07548. Epub 2022 Jun 15.

Authors

Zhe Guo^{1

2}, Gang Wu^{1

2}, Xiaojian Tan^{1

2}, Ruoyu Wang^{1

2}, Zipeng Yan¹, Qiang Zhang^{1

2}, Kun Song¹, Peng Sun^{1

2}, Haoyang Hu¹, Chen Cui¹, Guo-Qiang Liu^{1

2}, Jun Jiang^{1

2}

Affiliations

¹ Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
² University of Chinese Academy of Sciences, Beijing 100049, China.

PMID: 35704789
DOI: 10.1021/acsami.2c07548

Abstract

In the mid-temperature region, SnTe is a promising substitute for PbTe, whereas the thermoelectric (TE) property of pristine SnTe is severely limited by the good thermal conductivity and inferior Seebeck coefficient. In this research, we synergistically manipulate the interdependent TE parameters of SnTe-AgBiTe₂ alloys by Mn doping to increase the ZT value. The AgBiTe₂ alloying is found to greatly reduce the electrical conductivity and electronic contribution for thermal transport by reducing the carrier mobility, while Mn doping obviously improves the Seebeck coefficient by effectively decreasing the valence band offset. The lowest κ_l of Mn-doped SnTe-AgBiTe₂ alloys is 0.49 W m^-1 K^-1 at 823 K since the various defects strengthen the phonon scattering. Collectively, these manipulations yield a peak ZT value of 1.40 at 823 K and an average ZT value of 0.73 (300-823 K) in the Mn-doped SnTe-AgBiTe₂ alloys. This research suggests that Mn doping is a valid scheme to constantly improve the thermoelectric property of SnTe-AgBiTe₂ alloys in a wide temperature range.

Keywords: Mn doping; SnTe; band convergence; conversion efficiency; thermoelectric.