Electrical Transport and Thermoelectric Properties of SnSe–SnTe Solid Solution
| Autor: | Chan Park, Jun-Young Cho, Muhammad Siyar, Woo Chan Jin, Seong-Hyeon Hong, Euyheon Hwang, Miyoung Kim, Seung-Hwan Bae |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Band gap thermoelectric lcsh:Technology Article Thermal conductivity Electrical resistivity and conductivity Thermoelectric effect te substitution General Materials Science Electronic band structure lcsh:Microscopy lcsh:QC120-168.85 Condensed matter physics Phonon scattering lcsh:QH201-278.5 lcsh:T tin selenide lcsh:TA1-2040 lcsh:Descriptive and experimental mechanics solid solution lcsh:Electrical engineering. Electronics. Nuclear engineering lcsh:Engineering (General). Civil engineering (General) Single crystal lcsh:TK1-9971 spark plasma sintering Solid solution |
| Zdroj: | Materials, Vol 12, Iss 23, p 3854 (2019) Materials Volume 12 Issue 23 |
| ISSN: | 1996-1944 |
| Popis: | SnSe is considered as a promising thermoelectric (TE) material since the discovery of the record figure of merit (ZT) of 2.6 at 926 K in single crystal SnSe. It is, however, difficult to use single crystal SnSe for practical applications due to the poor mechanical properties and the difficulty and cost of fabricating a single crystal. It is highly desirable to improve the properties of polycrystalline SnSe whose TE properties are still not near to that of single crystal SnSe. In this study, in order to control the TE properties of polycrystalline SnSe, polycrystalline SnSe&ndash SnTe solid solutions were fabricated, and the effect of the solid solution on the electrical transport and TE properties was investigated. The SnSe1&minus xTex samples were fabricated using mechanical alloying and spark plasma sintering. X-ray diffraction (XRD) analyses revealed that the solubility limit of Te in SnSe1&minus xTex is somewhere between x = 0.3 and 0.5. With increasing Te content, the electrical conductivity was increased due to the increase of carrier concentration, while the lattice thermal conductivity was suppressed by the increased amount of phonon scattering. The change of carrier concentration and electrical conductivity is explained using the measured band gap energy and the calculated band structure. The change of thermal conductivity is explained using the change of lattice thermal conductivity from the increased amount of phonon scattering at the point defect sites. A ZT of ~0.78 was obtained at 823 K from SnSe0.7Te0.3, which is an ~11% improvement compared to that of SnSe. |
| Databáze: | OpenAIRE |
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