TY  - JOUR
AU  - Zhang, Fudong
AU  - Qi, Guanxiao
AU  - He, Mingkai
AU  - Zheng, Fengshan
AU  - Jin, Lei
AU  - Peng, Zhanhui
AU  - Chao, Xiaolian
AU  - Yang, Zupei
AU  - Wu, Di
TI  - Contrasting roles of Bi-doping and Bi 2 Te 3 alloying on the thermoelectric performance of SnTe
JO  - Inorganic chemistry frontiers
VL  - 9
IS  - 21
SN  - 2052-1545
CY  - Cambridge
PB  - RSC
M1  - FZJ-2022-04668
SP  - 5562 - 5571
PY  - 2022
AB  - Previous studies have revealed that both Bi doping and Bi2Te3 alloying are successful strategies to optimize the thermoelectric performance of SnTe; however, detailed and thorough investigations on exactly how they differ in modulating the band structure and microstructure were seldom given. Through a systematic comparison between Bi-doped and Bi2Te3-alloyed SnTe, we find in this work that despite the fact that they both contribute to the valence band convergence of SnTe, Bi2Te3 alloying induces little effect on the hole concentration unlike the typical n-type feature of Bi-doping; moreover, Bi2Te3 alloying tends to produce dense dislocation arrays at micron-scale grain boundaries which differs significantly from the substitutional point defect character upon Bi-doping. It was then found that Bi2Te3 alloying exhibits a relatively higher quality factor (B ∼ μw/κlat) at higher temperatures than Bi-doping. Subsequent Ge-doping in Bi2Te3-alloyed samples results in further valence band convergence and hole concentration optimization and eventually results in a maximum figure of merit ZT of 1.4 at 873 K in the composition of (Sn0.88Ge0.12Te)0.97-(BiTe1.5)0.03.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000853004700001
DO  - DOI:10.1039/D2QI01437H
UR  - https://juser.fz-juelich.de/record/911385
ER  -