In-Situ Observation of the Continuous Phase Transition in Determining the High Thermoelectric Performance of Polycrystalline Sn0.98Se

Matthew Dargusch, Xiao Lei Shi, Xuan Quy Tran, Tianli Feng, Flora Somidin, Xin Tan, Weidi Liu, Kevin Jack, Jeffrey Venezuela, Hiroshi Maeno, Takaaki Toriyama, Syo Matsumura, Sokrates T. Pantelides, Zhi Gang Chen

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)

Abstract

We report a comprehensive in-situ phase-change study on polycrystalline Sn0.98Se via high-temperature X-ray diffraction and in-situ high-voltage transmission electron microscopy from room temperature to 843 K. The results clearly demonstrate a continuous phase transition from Pnma to Cmcm starting from 573 to 843 K, rather than a sudden transition at 800 K. We also find that the thermal-conductivity rise at high temperature after the phase transition, as commonly seen in pristine SnSe, does not occur in Sn0.98Se, leading to a high thermoelectric figure of merit. Density functional theory calculations reveal the origin to be the suppression of bipolar thermal conduction in the Cmcm phase of Sn0.98Se due to the enlarged bandgap. This work fills the gap of in-situ characterization on polycrystalline Sn0.98Se and provides new insights into the outstanding thermoelectric performance of polycrystalline Sn0.98Se.

Original languageEnglish
Pages (from-to)6512-6517
Number of pages6
JournalJournal of Physical Chemistry Letters
Volume10
Issue number21
DOIs
Publication statusPublished - Nov 7 2019

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'In-Situ Observation of the Continuous Phase Transition in Determining the High Thermoelectric Performance of Polycrystalline Sn<sub>0.98</sub>Se'. Together they form a unique fingerprint.

Cite this