High thermoelectric performance and low thermal conductivity in K-doped SnSe polycrystalline compounds
| Autor: | Kyunghan Ahn, Jong-Soo Rhyee, Chan-Chieh Lin, Gareoung Kim, Dianta Ginting |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Electron mobility
Materials science Phonon scattering Doping Analytical chemistry General Physics and Astronomy Sintering 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Thermal conductivity Thermoelectric effect General Materials Science Crystallite 0210 nano-technology Single crystal |
| Zdroj: | Current Applied Physics. 18:1534-1539 |
| ISSN: | 1567-1739 |
| DOI: | 10.1016/j.cap.2018.09.011 |
| Popis: | SnSe single crystal showed a high thermoelectric zT of 2.6 at 923 K mainly due to an extremely low thermal conductivity 0.23 W m−1 K−1. It has anisotropic crystal structure resulting in deterioration of thermoelectric performance in polycrystalline SnSe, providing a low zT of 0.6 and 0.8 for Ag and Na-doped SnSe, respectively. Here, we presented the thermoelectric properties on the K-doped KxSn1−xSe (x = 0, 0.1, 0.3, 0.5, 1.5, and 2.0%) polycrystals, synthesized by a high-temperature melting and hot-press sintering with annealing process. The K-doping in SnSe efficiently enhances the hole carrier concentration without significant degradation of carrier mobility. We find that there exist widespread Se-rich precipitates, inducing strong phonon scattering and thus resulting in a very low thermal conductivity. Due to low thermal conductivity and moderate power factor, the K0.001Sn0.999Se sample shows an exceptionally high zT of 1.11 at 823 K which is significantly enhanced value in polycrystalline compounds. |
| Databáze: | OpenAIRE |
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