Abstract
We report on the underlying mechanism that enables the SnTe-AgSbTe2 system to exhibit superior thermoelectric figure of merit (ZT) compared to its parent compound SnTe. We show that AgSbTe2 alloying has a profound impact on the band structure of SnTe by converging the energies of its light and heavy valence bands, leading to significantly enhanced Seebeck coefficients. We have also unraveled a significant connection between alloying and defect stability in this system, wherein the Sn vacancy concentration increases significantly when Ag and Sb are alloyed on the Sn site. The increased Sn vacancy concentration dramatically reduces the lattice thermal conductivity through both lattice softening and phonon-vacancy scattering to ∼0.4 W m-1 K-1 at 800 K. Consequently, a ZT value of 1.2 at 800 K for AgSn5SbTe7 can be achieved by doping I on Te sites. This represents a 300% improvement over pristine SnTe, outperforming many reported SnTe-based thermoelectric materials.
| Original language | English |
|---|---|
| Pages (from-to) | 705-712 |
| Number of pages | 8 |
| Journal | ACS Energy Letters |
| Volume | 3 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Mar 9 2018 |
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ASJC Scopus subject areas
- Chemistry (miscellaneous)
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Energy Engineering and Power Technology
- Materials Chemistry
Cite this
High Thermoelectric Performance in SnTe-AgSbTe2 Alloys from Lattice Softening, Giant Phonon-Vacancy Scattering, and Valence Band Convergence. / Tan, Gangjian; Hao, Shiqiang; Hanus, Riley C.; Zhang, Xiaomi; Anand, Shashwat; Bailey, Trevor P.; Rettie, Alexander J.E.; Su, Xianli; Uher, Ctirad; Dravid, Vinayak P.; Snyder, G. Jeffrey; Wolverton, Chris; Kanatzidis, Mercouri G.
In: ACS Energy Letters, Vol. 3, No. 3, 09.03.2018, p. 705-712.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - High Thermoelectric Performance in SnTe-AgSbTe2 Alloys from Lattice Softening, Giant Phonon-Vacancy Scattering, and Valence Band Convergence
AU - Tan, Gangjian
AU - Hao, Shiqiang
AU - Hanus, Riley C.
AU - Zhang, Xiaomi
AU - Anand, Shashwat
AU - Bailey, Trevor P.
AU - Rettie, Alexander J.E.
AU - Su, Xianli
AU - Uher, Ctirad
AU - Dravid, Vinayak P.
AU - Snyder, G. Jeffrey
AU - Wolverton, Chris
AU - Kanatzidis, Mercouri G
PY - 2018/3/9
Y1 - 2018/3/9
N2 - We report on the underlying mechanism that enables the SnTe-AgSbTe2 system to exhibit superior thermoelectric figure of merit (ZT) compared to its parent compound SnTe. We show that AgSbTe2 alloying has a profound impact on the band structure of SnTe by converging the energies of its light and heavy valence bands, leading to significantly enhanced Seebeck coefficients. We have also unraveled a significant connection between alloying and defect stability in this system, wherein the Sn vacancy concentration increases significantly when Ag and Sb are alloyed on the Sn site. The increased Sn vacancy concentration dramatically reduces the lattice thermal conductivity through both lattice softening and phonon-vacancy scattering to ∼0.4 W m-1 K-1 at 800 K. Consequently, a ZT value of 1.2 at 800 K for AgSn5SbTe7 can be achieved by doping I on Te sites. This represents a 300% improvement over pristine SnTe, outperforming many reported SnTe-based thermoelectric materials.
AB - We report on the underlying mechanism that enables the SnTe-AgSbTe2 system to exhibit superior thermoelectric figure of merit (ZT) compared to its parent compound SnTe. We show that AgSbTe2 alloying has a profound impact on the band structure of SnTe by converging the energies of its light and heavy valence bands, leading to significantly enhanced Seebeck coefficients. We have also unraveled a significant connection between alloying and defect stability in this system, wherein the Sn vacancy concentration increases significantly when Ag and Sb are alloyed on the Sn site. The increased Sn vacancy concentration dramatically reduces the lattice thermal conductivity through both lattice softening and phonon-vacancy scattering to ∼0.4 W m-1 K-1 at 800 K. Consequently, a ZT value of 1.2 at 800 K for AgSn5SbTe7 can be achieved by doping I on Te sites. This represents a 300% improvement over pristine SnTe, outperforming many reported SnTe-based thermoelectric materials.
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U2 - 10.1021/acsenergylett.8b00137
DO - 10.1021/acsenergylett.8b00137
M3 - Article
VL - 3
SP - 705
EP - 712
JO - ACS Energy Letters
JF - ACS Energy Letters
SN - 2380-8195
IS - 3
ER -