Enhanced Thermoelectric Performance via Oxygen Manipulation in BiCuTeO

MRS Advances ◽  
2019 ◽  
Vol 4 (08) ◽  
pp. 499-505 ◽  
Author(s):  
Hui-Ching Chang ◽  
Hao-Jen You ◽  
Raman Sankar ◽  
Ying-Jay Yang ◽  
Li-Chyong Chen ◽  
...  

AbstractBiCuTeO is a potential thermoelectric material owing to its low thermal conductivity and high carrier concentration. However, the thermoelectric performance of BiCuTeO is still below average and has much scope for improvement. In this study, we manipulated the nominal oxygen content in BiCuTeO and synthesized BiCuTeOx (x = 0.94–1.06) bulks by a solid-state reaction and pelletized them by a cold-press method. The power factor was enhanced by varying the nominal oxygen deficiency due to the increased Seebeck coefficient. The thermal conductivity was also reduced due to the decrease in lattice thermal conductivity owing to the small grain size generated by the optimal nominal oxygen content. Consequently, the ZT value was enhanced by ∼11% at 523 K for stoichiometric BiCuTeO0.94 compared to BiCuTeO. Thus, optimal oxygen manipulation in BiCuTeO can enhance the thermoelectric performance. This study can be applied to developing oxides with high thermoelectric performances.

RSC Advances ◽  
2019 ◽  
Vol 9 (54) ◽  
pp. 31747-31752 ◽  
Author(s):  
Min Li ◽  
Yong Luo ◽  
Xiaojuan Hu ◽  
Zhongkang Han ◽  
Xianglian Liu ◽  
...  

Co-regulation of both the copper vacancy concentration (Vc) and point defect GaIn realizing the high carrier concentration and low lattice thermal conductivity in Cu3In5Te9-based chalcogenides simultaneously.


Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Muchun Guo ◽  
Fengkai Guo ◽  
Jianbo Zhu ◽  
Li Yin ◽  
Qian Zhang ◽  
...  

CaMg2Bi2-based compounds, a kind of the representative compounds of Zintl phases, have uniquely inherent layered structure and hence are considered to be potential thermoelectric materials. Generally, alloying is a traditional and effective way to reduce the lattice thermal conductivity through the mass and strain field fluctuation between host and guest atoms. The cation sites have very few contributions to the band structure around the fermi level; thus, cation substitution may have negligible influence on the electric transport properties. What is more, widespread application of thermoelectric materials not only desires high ZT value but also calls for low-cost and environmentally benign constituent elements. Here, Ba substitution on cation site achieves a sharp reduction in lattice thermal conductivity through enhanced point defects scattering without the obvious sacrifice of high carrier mobility, and thus improves thermoelectric properties. Then, by combining further enhanced phonon scattering caused by isoelectronic substitution of Zn on the Mg site, an extraordinarily low lattice thermal conductivity of 0.51 W m-1 K-1 at 873 K is achieved in (Ca0.75Ba0.25)0.995Na0.005Mg1.95Zn0.05Bi1.98 alloy, approaching the amorphous limit. Such maintenance of high mobility and realization of ultralow lattice thermal conductivity synergistically result in broadly improvement of the quality factor β. Finally, a maximum ZT of 1.25 at 873 K and the corresponding ZTave up to 0.85 from 300 K to 873 K have been obtained for the same composition, meanwhile possessing temperature independent compatibility factor. To our knowledge, the current ZTave exceeds all the reported values in AMg2Bi2-based compounds so far. Furthermore, the low-cost and environment-friendly characteristic plus excellent thermoelectric performance also make the present Zintl phase CaMg2Bi2 more competitive in practical application.


2021 ◽  
Author(s):  
Jun-Liang Chen ◽  
Hengquan Yang ◽  
Chengyan Liu ◽  
Jisheng Liang ◽  
Lei Miao ◽  
...  

Abstract Half-Heusler alloys, which possess the advantages of high thermal stability, large power factor and good mechanical property, have been attracted increasing interest in mid-temperature thermoelectric application. In this work, the extra Zr-doped TiZrxNiSn samples were successfully prepared by a modified solid-state reaction followed by spark plasma sintering. It demonstrates that extra Zr doping could not only improve the power factor on account of an increase in Seebeck coefficient but also suppress the lattice thermal conductivity originated from the strengthened phonon scattering by the superlattice nanodomains and the secondary nanoparticles. As a consequence, an increased power factor of 3.29 mW m− 1 K− 2 and a decreased lattice thermal conductivity of 1.74 W m− 1 K− 1 are achieved in TiZr0.015NiSn, leading to a peak ZT as high as 0.88 at 773 K and an average ZT value up to 0.62 in the temperature range of 373 − 773 K. This work gives a guidance for optimizing the thermoelectric performance of TiNiSn-based alloys by modulating the microstructures on the secondary nanophases and superlattice nanodomains.


Author(s):  
Jingdan Lei ◽  
Hexige Wuliji ◽  
Kunpeng Zhao ◽  
Tian-Ran Wei ◽  
Qing Xu ◽  
...  

Mg3Sb2-based thermoelectric materials have recently received heightened attentions due to its diverse merits of high band degeneracy, ultralow lattice thermal conductivity and high carrier mobility. However, the inherently low carrier...


Author(s):  
Zihang Liu ◽  
Wenhao Zhang ◽  
Weihong Gao ◽  
Takao Mori

Discovering materials with the intrinsically low lattice thermal conductivity κlat is an important route for achieving high thermoelectric performance. In reality, the conventional synthetic approach, however, relies on trial and...


RSC Advances ◽  
2021 ◽  
Vol 11 (25) ◽  
pp. 15486-15496
Author(s):  
Enamul Haque

The layered structure, and presence of heavier elements Rb/Cs and Sb induce high anharmonicity, low Debye temperature, intense phonon scattering, and hence, low lattice thermal conductivity.


2005 ◽  
Vol 87 (2) ◽  
pp. 023105 ◽  
Author(s):  
J. C. Caylor ◽  
K. Coonley ◽  
J. Stuart ◽  
T. Colpitts ◽  
R. Venkatasubramanian

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