Enhancing p-Type Thermoelectric Performances of Polycrystalline SnSe via Tuning Phase Transition Temperature
| Autor: | Taeghwan Hyeon, Jae-Hyuk Park, Hyo Seok Kim, Kyunghan Ahn, Garam Choi, Yong Kyu Lee, Sang-Hyun Park, Yung-Eun Sung, Joonil Cha, In Chung, Won Bo Lee, Chongjian Zhou, Sue In Chae, Sung-Pyo Cho |
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| Rok vydání: | 2017 |
| Předmět: |
Condensed matter physics
Chemistry Transition temperature Doping Energy conversion efficiency 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Thermoelectric materials Thermal conduction 01 natural sciences Biochemistry Catalysis 0104 chemical sciences Colloid and Surface Chemistry Electrical resistivity and conductivity Thermoelectric effect Crystallite 0210 nano-technology |
| Zdroj: | Journal of the American Chemical Society. 139:10887-10896 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/jacs.7b05881 |
| Popis: | SnSe emerges as a new class of thermoelectric materials since the recent discovery of an ultrahigh thermoelectric figure of merit in its single crystals. Achieving such performance in the polycrystalline counterpart is still challenging and requires fundamental understandings of its electrical and thermal transport properties as well as structural chemistry. Here we demonstrate a new strategy of improving conversion efficiency of bulk polycrystalline SnSe thermoelectrics. We show that PbSe alloying decreases the transition temperature between Pnma and Cmcm phases and thereby can serve as a means of controlling its onset temperature. Along with 1% Na doping, delicate control of the alloying fraction markedly enhances electrical conductivity by earlier initiation of bipolar conduction while reducing lattice thermal conductivity by alloy and point defect scattering simultaneously. As a result, a remarkably high peak ZT of ∼1.2 at 773 K as well as average ZT of ∼0.5 from RT to 773 K is achieved for Na0.01(Sn1... |
| Databáze: | OpenAIRE |
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