Thermoelectric transport properties in Bi-doped SnTe–SnSe alloys
Thermoelectric transport properties in Bi-doped SnTe–SnSe alloys
复制标题
Bi掺杂SnTe-SnSe合金的热电输运特性
DOI：
10.1063/1.5145186
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发表时间：
2020-03
影响因子：
4
通讯作者：
Ang Ran
中科院分区：
文献类型：
--
作者：
Guo Xuming;Chen Zhiyu;Tang Jing;Zhang Fujie;Zhong Yan;Liu Hangtian;Ang Ran
已经做出了许多努力来推进热电SnTe的潜在应用。有效的策略集中在输运性质的操纵，包括价带收敛，共振态，和缺陷工程。已经证明，在SnTe中单独合金化三价Bi或硫属化物SnSe可以引发热电性能的固有增强。然而，Bi和Se共掺杂在SnTe中的传输价带中起着什么样的关键作用仍然不清楚。特别是，充分评估带收敛对载流子浓度依赖的加权迁移率的影响，这主导了电子性能，是设计优良的热电材料的首要和必要的。在这里，我们报告说，Bi掺杂在SnTe-SnSe合金可以得到一个明显的减少，在两个价带之间的能量偏移，从而提高状态密度的有效质量，只有轻微恶化的流动性。理论模型表明，Bi掺杂诱导的能带收敛和优化的载流子浓度实际上提高了加权迁移率，有助于电子性能的改善。此外，Debye-Callaway模型证明了约化晶格热导率的起源。目前的结果证实了运输工程在提高热电性能方面的潜力。
Numerous endeavors have been made to advance thermoelectric SnTe for potential applications. Effective strategies focus on the manipulation of transport properties, including valence band convergence, resonate state, and defect engineering. It has been demonstrated that alloying trivalent Bi or chalcogenide SnSe alone in SnTe can trigger an inherent enhancement of thermoelectric performance. However, what the critical role in the transport valence band co-doping Bi and Se in SnTe plays is still unclear. Particularly, fully evaluating the effect of band convergence on the carrier concentration-dependent weighted mobility, which dominates the electronic performance, is primary and essential for designing excellent thermoelectric materials. Here, we report that Bi doping in SnTe–SnSe alloys can derive a distinct decrease in the energy offset between the two valence bands, thus improving the density-of-state effective mass by only slightly deteriorating the mobility. The well-established theoretical model reveals that the Bi-doping-induced band convergence and the optimized carrier concentration actually enhance the weighted mobility, contributing to the improvement of electronic performance. Moreover, the Debye–Callaway model demonstrates the origin of the reduced lattice thermal conductivity. The present results confirm the potential of transport engineering in promoting thermoelectric performance.
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影响因子：
41.2
作者：
Liu, Huili;Shi, Xun;Snyder, G. Jeffrey
通讯作者：
Snyder, G. Jeffrey
影响因子：
64.8
作者：
Biswas, Kanishka;He, Jiaqing;Kanatzidis, Mercouri G.
通讯作者：
Kanatzidis, Mercouri G.
影响因子：
--
作者：
ABELES, B
通讯作者：
ABELES, B
影响因子：
32.5
作者：
Liu, Weishu;Lukas, Kevin C.;Ren, Zhifeng
通讯作者：
Ren, Zhifeng
影响因子：
8.6
作者：
Banik, Ananya;Shenoy, U. Sandhya;Biswas, Kanishka
通讯作者：
Biswas, Kanishka