Multi-role of Sodium Doping in BiCuSeO on High Thermoelectric Performance
Multi-role of Sodium Doping in BiCuSeO on High Thermoelectric Performance
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DOI：
10.1007/s11664-015-3700-1
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发表时间：
2015-03
影响因子：
2.1
通讯作者：
Mingyang Zhang;Junyou Yang;Q. Jiang;L. Fu;Ye Xiao;Yubo Luo;Dan Zhang;Yudong Cheng;Zhiwei Zhou-Zhi
中科院分区：
文献类型：
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作者：
Mingyang Zhang;Junyou Yang;Q. Jiang;L. Fu;Ye Xiao;Yubo Luo;Dan Zhang;Yudong Cheng;Zhiwei Zhou-Zhi
本文制备了Na掺杂的BiCuSeO热电材料，研究了Na掺杂对BiCuSeO热电材料微观结构和热电性能的影响。当掺杂量小于6%时，Na+全部溶解到基体中，取代Bi 3+位，起到受主作用;当掺杂量大于6%时，取代饱和，过量掺杂导致Na 2CO 3和Na 2SeO 3第二相的形成。一方面，Na+对Bi 3+的掺杂由于载流子浓度的显著增加，可以显著改善电性能。此外，由于Na+掺杂引起的点缺陷和第二相对声子的散射，声子和总热导率也随Na+掺杂的增加而降低。因此，热电性能得到了提高，并且对于Bi 0.92Na 0.08CuSeO样品，在873 K处实现了0.97的最大ZT值，其大约是未掺杂BiCuSeO的三倍。
In this work, Na-doped BiCuSeO thermoelectric materials have been prepared and the effect of Na doping on their microstructure and thermoelectric properties has been studied. When the doping content is less than 6%, all Na+can dissolve into the matrix and substitute for Bi3+sites and play a role of acceptor; when the content is above 6%, the substitution saturates and excessive doping results in the formation of Na2CO3and Na2SeO3secondary phases. On the one hand, the doping of Na+for Bi3+can significantly improve the electrical properties due to the significant increase of carrier concentration. Furthermore, the phonon and total thermal conductivity also decrease with Na doping because of the dual phonon scattering by the point defects and secondary phases both resulting from Na+doping. As a result, the thermoelectric performance is enhanced, and a maximumZTvalue of 0.97, which is approximately triple that of the undoped BiCuSeO, is achieved at 873 K for the Bi0.92Na0.08CuSeO sample.