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Improving near-room-temperature thermoelectrics in SnTe–MnTe alloys
- Source :
- Applied Physics Letters. 116:193902
- Publication Year :
- 2020
- Publisher :
- AIP Publishing, 2020.
-
Abstract
- The rich capabilities for both electronic and phonon engineering in SnTe are highly desirable for achieving high thermoelectric performance. Alloying high-solubility MnTe (∼15%) leads to substitutional defects for reducing lattice thermal conductivity and band convergence for enhancing electronic performance, and thus, an improvement of thermoelectric performance of SnTe is realized. However, there is no evidence that the electronic and phonon transport properties are fully optimized in SnTe-15%MnTe thermoelectrics, especially for the near-room-temperature (< 573 K) thermoelectric performance, which still needs a sufficient promotion. Here, the substituted 2% Bi in SnTe-15%MnTe alloys dramatically increases the near-room-temperature zT and peak zT to ∼0.72 (at 550 K) and ∼1.3 (at 850 K), respectively. Combining the experimental evidence and the first-principles calculations, we demonstrate that the prominent enhancement of electronic performance arises from the Bi-doping-driven transport valence band alignment and the carrier concentration optimization. Furthermore, the Debye–Callaway model verifies that the reduction in lattice thermal conductivity is dominated by the Bi substitutional defects. The present findings reveal the importance of transport engineering in achieving high thermoelectric performance particularly near room temperature.
- Subjects :
- 010302 applied physics
Materials science
Physics and Astronomy (miscellaneous)
Condensed matter physics
Phonon
02 engineering and technology
021001 nanoscience & nanotechnology
Thermoelectric materials
01 natural sciences
Reduction (complexity)
Lattice thermal conductivity
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...........5eebb3eff38b297014d7f1c6b1e5ca5b