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Enhancing thermoelectric and mechanical performances in BiCuSeO by increasing bond covalency and nanostructuring.
- Source :
-
Journal of Solid State Chemistry . Sep2018, Vol. 265, p306-313. 8p. - Publication Year :
- 2018
-
Abstract
- Abstract The layered oxyselenide BiCuSeO thermoelectric ceramics are attracting much scientific attention for its excellent thermoelectric properties. Herein, Bi 1- x Sb x CuSe 1- x Te x O ( x = 0, 0.01, 0.02, 0.04, 0.06, 0.08) ceramics have been prepared by ball milling (BM) and resistance pressing sintering (RPS) process. The effects of Sb/Te doping and grain size on the thermoelectric/mechanical properties are investigated systematically. For the former, it can tune the Fermi level and promote the band convergence, decreasing the band gap and concurrently enhancing the carrier concentration; for the latter, it can profoundly modify microstructure into an all-scale hierarchical architecture to scatter phonons with broad range of mean free paths, effectively reducing the lattice thermal conductivity. The results indicates that the substitution of Sb/Te resulted in the significantly increase of electrical conductivity and power factor, and BM effectively reduces the grain size to ~ 387 nm in the sample after sintering, which leads to a decrease in the thermal conductivity and an increase in the electrical conductivity. The maximum power factor of 0.72 m Wm−1 K−2 and ZT value of 1.19 were obtained for Bi 0.92 Sb 0.08 CuSe 0.92 Te 0.08 O with BM time = 16 h at 873 K, which was ~ 2.7 and ~ 2.2 times as that of the pristine BiCuSeO ceramic. Graphical abstract Sb/Te doping combined with grain refining led to the great increase of BiCuSeO based ceramics(sample 0–3 stand for ball milling time=5 h, 8 h, 12 h 16 h, respectively) fx1 [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00224596
- Volume :
- 265
- Database :
- Academic Search Index
- Journal :
- Journal of Solid State Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 131526172
- Full Text :
- https://doi.org/10.1016/j.jssc.2018.06.011