Abstract
Sb-doped and GeTe-alloyed n-type thermoelectric materials that show an excellent figure of merit ZT in the intermediate temperature range (400–800 K) are reported. The synergistic effect of favorable changes to the band structure resulting in high Seebeck coefficient and enhanced phonon scattering by point defects and nanoscale precipitates resulting in reduction of thermal conductivity are demonstrated. The samples can be tuned as single-phase solid solution (SS) or two-phase system with nanoscale precipitates (Nano) based on the annealing processes. The GeTe alloying results in band structure modification by widening the bandgap and increasing the density-of-states effective mass of PbTe, resulting in significantly enhanced Seebeck coefficients. The nanoscale precipitates can improve the power factor in the low temperature range and further reduce the lattice thermal conductivity (κlat). Specifically, the Seebeck coefficient of Pb0.988Sb0.012Te–13%GeTe–Nano approaches −280 µV K−1 at 673 K with a low κlat of 0.56 W m−1 K−1 at 573 K. Consequently, a peak ZT value of 1.38 is achieved at 623 K. Moreover, a high average ZTavg value of ≈1.04 is obtained in the temperature range from 300 to 773 K for n-type Pb0.988Sb0.012Te–13%GeTe–Nano.
| Original language | English |
|---|---|
| Article number | 1801617 |
| Journal | Advanced Functional Materials |
| Volume | 28 |
| Issue number | 31 |
| DOIs | |
| Publication status | Published - Aug 1 2018 |
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Keywords
- GeTe alloying
- n-type PbTe
- thermal conductivity
- thermoelectric materials
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Biomaterials
- Condensed Matter Physics
- Electrochemistry
Cite this
High Thermoelectric Performance in Supersaturated Solid Solutions and Nanostructured n-Type PbTe–GeTe. / Luo, Zhong Zhen; Zhang, Xiaomi; Hua, Xia; Tan, Gangjian; Bailey, Trevor P.; Xu, Jianwei; Uher, Ctirad; Wolverton, Chris; Dravid, Vinayak P.; Yan, Qingyu; Kanatzidis, Mercouri G.
In: Advanced Functional Materials, Vol. 28, No. 31, 1801617, 01.08.2018.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - High Thermoelectric Performance in Supersaturated Solid Solutions and Nanostructured n-Type PbTe–GeTe
AU - Luo, Zhong Zhen
AU - Zhang, Xiaomi
AU - Hua, Xia
AU - Tan, Gangjian
AU - Bailey, Trevor P.
AU - Xu, Jianwei
AU - Uher, Ctirad
AU - Wolverton, Chris
AU - Dravid, Vinayak P.
AU - Yan, Qingyu
AU - Kanatzidis, Mercouri G
PY - 2018/8/1
Y1 - 2018/8/1
N2 - Sb-doped and GeTe-alloyed n-type thermoelectric materials that show an excellent figure of merit ZT in the intermediate temperature range (400–800 K) are reported. The synergistic effect of favorable changes to the band structure resulting in high Seebeck coefficient and enhanced phonon scattering by point defects and nanoscale precipitates resulting in reduction of thermal conductivity are demonstrated. The samples can be tuned as single-phase solid solution (SS) or two-phase system with nanoscale precipitates (Nano) based on the annealing processes. The GeTe alloying results in band structure modification by widening the bandgap and increasing the density-of-states effective mass of PbTe, resulting in significantly enhanced Seebeck coefficients. The nanoscale precipitates can improve the power factor in the low temperature range and further reduce the lattice thermal conductivity (κlat). Specifically, the Seebeck coefficient of Pb0.988Sb0.012Te–13%GeTe–Nano approaches −280 µV K−1 at 673 K with a low κlat of 0.56 W m−1 K−1 at 573 K. Consequently, a peak ZT value of 1.38 is achieved at 623 K. Moreover, a high average ZTavg value of ≈1.04 is obtained in the temperature range from 300 to 773 K for n-type Pb0.988Sb0.012Te–13%GeTe–Nano.
AB - Sb-doped and GeTe-alloyed n-type thermoelectric materials that show an excellent figure of merit ZT in the intermediate temperature range (400–800 K) are reported. The synergistic effect of favorable changes to the band structure resulting in high Seebeck coefficient and enhanced phonon scattering by point defects and nanoscale precipitates resulting in reduction of thermal conductivity are demonstrated. The samples can be tuned as single-phase solid solution (SS) or two-phase system with nanoscale precipitates (Nano) based on the annealing processes. The GeTe alloying results in band structure modification by widening the bandgap and increasing the density-of-states effective mass of PbTe, resulting in significantly enhanced Seebeck coefficients. The nanoscale precipitates can improve the power factor in the low temperature range and further reduce the lattice thermal conductivity (κlat). Specifically, the Seebeck coefficient of Pb0.988Sb0.012Te–13%GeTe–Nano approaches −280 µV K−1 at 673 K with a low κlat of 0.56 W m−1 K−1 at 573 K. Consequently, a peak ZT value of 1.38 is achieved at 623 K. Moreover, a high average ZTavg value of ≈1.04 is obtained in the temperature range from 300 to 773 K for n-type Pb0.988Sb0.012Te–13%GeTe–Nano.
KW - GeTe alloying
KW - n-type PbTe
KW - thermal conductivity
KW - thermoelectric materials
UR - http://www.scopus.com/inward/record.url?scp=85051077440&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85051077440&partnerID=8YFLogxK
U2 - 10.1002/adfm.201801617
DO - 10.1002/adfm.201801617
M3 - Article
AN - SCOPUS:85051077440
VL - 28
JO - Advanced Functional Materials
JF - Advanced Functional Materials
SN - 1616-301X
IS - 31
M1 - 1801617
ER -