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Thermoelectric transport properties in Bi-doped SnTe–SnSe alloys
- Source :
- Applied Physics Letters. 116:103901
- Publication Year :
- 2020
- Publisher :
- AIP Publishing, 2020.
-
Abstract
- Numerous endeavors have been made to advance thermoelectric SnTe for potential applications. Effective strategies focus on the manipulation of transport properties, including valence band convergence, resonate state, and defect engineering. It has been demonstrated that alloying trivalent Bi or chalcogenide SnSe alone in SnTe can trigger an inherent enhancement of thermoelectric performance. However, what the critical role in the transport valence band co-doping Bi and Se in SnTe plays is still unclear. Particularly, fully evaluating the effect of band convergence on the carrier concentration-dependent weighted mobility, which dominates the electronic performance, is primary and essential for designing excellent thermoelectric materials. Here, we report that Bi doping in SnTe–SnSe alloys can derive a distinct decrease in the energy offset between the two valence bands, thus improving the density-of-state effective mass by only slightly deteriorating the mobility. The well-established theoretical model reveals that the Bi-doping-induced band convergence and the optimized carrier concentration actually enhance the weighted mobility, contributing to the improvement of electronic performance. Moreover, the Debye–Callaway model demonstrates the origin of the reduced lattice thermal conductivity. The present results confirm the potential of transport engineering in promoting thermoelectric performance.
- Subjects :
- 010302 applied physics
Thermoelectric transport
Valence (chemistry)
Materials science
Physics and Astronomy (miscellaneous)
Condensed matter physics
Chalcogenide
Doping
02 engineering and technology
021001 nanoscience & nanotechnology
Thermoelectric materials
01 natural sciences
chemistry.chemical_compound
Effective mass (solid-state physics)
chemistry
0103 physical sciences
Thermoelectric effect
Valence band
0210 nano-technology
Subjects
Details
- ISSN :
- 10773118 and 00036951
- Volume :
- 116
- Database :
- OpenAIRE
- Journal :
- Applied Physics Letters
- Accession number :
- edsair.doi...........8a5c69df7d70589368c6367046a253b2