Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5460085 | Journal of Alloys and Compounds | 2017 | 44 Pages |
Abstract
We report n-type PbTe with a maximum ZT â¼1.2 at 673 K and an average ZTave â¼0.84 at 300-823 K, which was achieved through a Sn and Se co-alloying approach. We find that the lattice thermal conductivity can be largely reduced through introducing Se in Te sites, and the power factor can be enhanced through introducing Sn in the Pb sites. Combining two strategies via Se and Sn co-alloying in PbTe, results show that the lattice thermal conductivity at 300 K can be reduced from â¼3.1 Wmâ1Kâ1 to â¼1.2 Wmâ1Kâ1 after alloying 15% Se, which is consistent with the Callaway model. Meanwhile, we find that both carrier concentration and mobility can be enhanced through alloying small amount of Sn, which are supported by DFT calculation with emphasis on the defect formation energies. The improvement on electrical conductivity elucidates an enhanced power factor at 300 K increasing from â¼6.4 μWcmâ1Kâ2 to â¼14.6 μWcmâ1Kâ2. Through synergistically optimizing electrical and thermal transport properties of n-type PbTe via Sn and Se co-alloying, the ZT value is distinctly enhanced to 1.2 at 673 K, and the average ZTave value is improved by â¼35%, from â¼0.62 in PbTe0.997I0.003 to â¼0.84 in Pb0.995Sn0.005Te0.847Se0.15I0.003, ensuring a high maximum thermoelectric conversion efficiency â¼10.7%.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Yu Xiao, Wei Li, Cheng Chang, Yuexing Chen, Li Huang, Jiaqing He, Li-Dong Zhao,