Enhancement of Thermoelectric Properties in Pd−In Co-Doped SnTe and Its Phase Transition Behavior

Authors

Zheng Ma, Henan University
Jingdan Lei, Henan University
De Zhang, Henan University
Chao Wang, Henan UniversityFollow
Jian Li Wang, Henan UniversityFollow
Zhenxiang Cheng, Henan University, University of WollongongFollow
Yuanxu Wang, Henan University

RIS ID

139045

Publication Details

Ma, Z., Lei, J., Zhang, D., Wang, C., Wang, J., Cheng, Z. & Wang, Y. (2019). Enhancement of Thermoelectric Properties in Pd−In Co-Doped SnTe and Its Phase Transition Behavior. ACS Applied Materials and Interfaces, 11 (37), 33792-33802.

Abstract

SnTe has attracted more and more attention due to the similar band and crystal structure with high performance thermoelectric materials PbTe. Here, we introduced Pd into SnTe and the valence band convergence was confirmed by first-principles calculation. In the experimental process, we found that Pd-doped SnTe exhibit a reduced thermal conductivity because of softening chemical bonds and grain refining effects. To further improve the thermoelectric performance, Pd-In codoped SnTe samples were prepared, and the abnormal change of thermal conductivity was observed. The results of synchrotron powder diffraction suggest that the local phase transition (local structural distortions) near 400 K results in the first turn on thermal conductivity. Similarly, the second local phase transition in near 600 K observed by neutron powder diffraction lead to a decrease thermal conductivity of the sample. Finally, a peak thermoelectric figure of merit (ZT) ≈ 1.51 has been obtained in Sn0.98Pd0.025In0.025Te at 800 K.