Synergistic Compositional-Mechanical-Thermal Effects Leading to a Record High zT in n-Type V2VI3 Alloys Through Progressive Hot Deformation
Synergistic Compositional-Mechanical-Thermal Effects Leading to a Record High zT in n-Type V2VI3 Alloys Through Progressive Hot Deformation
复制标题
协同成分-机械-热效应通过渐进热变形导致 n 型 V2VI3 合金达到创纪录的高 zT
DOI：
10.1002/adfm.201803617
复制
发表时间：
2018-08-29
影响因子：
19
通讯作者：
Zeng, Xierong
中科院分区：
文献类型：
--
作者：
Hu, Lipeng;Zhang, Yang;Zeng, Xierong
Here a progressive hot deformation procedure that endows the benchmark n-type V2VI3 thermoelectric materials with short range disorder (multiple defects), long range order (crystallinity), and strong texture (nearly orientation order) is reported. Not only it is rare for these structural features to coexist but also these structural features elicit the synergistic compositional-mechanical-thermal effects, i.e., a profound interplay among the counts, magnitude, and temperature of hot deformation in relation to the as formed point defects, dislocations, textures, strain clusters, and distortions. Using progressively larger die sets and relatively low hot deformation temperature, rich multiscale microstructures concurrently with a high level of texture comparable to that of zone melted ingot are obtained. The strong donor-like effect significantly increases the majority carrier concentration, suppressing the detrimental bipolar effect. In addition, the multiscale microstructures yield an ultralow lattice thermal conductivity approximate to 0.31 W m(-1) K-1 at 405 K. A record zT approximate to 1.3 at 450 K are attained in progressively hot deformed n-type Bi1.95Sb0.05Te2.3Se0.7 through the synergistic effects. These results not only promise a better pairing between n-type and p-type legs in device fabrication but also bring our understanding of n-type V2VI3 alloys and hot deformation technique to a new level.
