Spontaneously promoted carrier mobility and strengthened phonon scattering in p-type YbZn2Sb2 via a nanocompositing approach
Spontaneously promoted carrier mobility and strengthened phonon scattering in p-type YbZn2Sb2 via a nanocompositing approach
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通过纳米复合方法自发提高 p 型 YbZn2Sb2 中的载流子迁移率并增强声子散射
DOI：
10.1016/j.nanoen.2017.11.019
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发表时间：
2018
期刊：
影响因子：
17.6
通讯作者：
Zhou Xiao-yuan
中科院分区：
文献类型：
--
作者：
Zhang Xiong;Zhang Bin;Peng Kun-ling;Shen Xing-chen;Wu Gui-tai;Yan Yan-ci;Luo Shi-jun;Lu Xu;Wang Guo-yu;Gu Hao-shuang;Zhou Xiao-yuan
通过纳米复合提高热电性能的传统策略集中在纳米结构相引起的声子散射增强上。在这里，展示了一种结合载流子迁移率促进和增强声子散射以同时改善电和热输运性质的有效方法。对于含InSb纳米夹杂的p型YbZn2Sb2，在整个测量温度范围内，InSb有效地提高了霍尔迁移率，从56 cm2V−1s− 1提高到300 K时的162 cm2V−1s− 1。同时，通过调整Yb空位的载流子密度优化导致Seebeck系数提高了46%，克服了InSb的负贡献。此外，纳米夹杂物引起的界面散射的帮助下，晶格热导率降低了45%，在720 K。结果，热电优值ZT提高了近三倍。我们相信，我们的方法提供了一个“组合策略”，以提高YbZn2Sb2基化合物的热电性能，并应适用于其他热电材料。
Conventional strategies for advancing thermoelectrics via nanocompositing focus on the enhanced phonon scattering induced by nanostructured phase. Here, an effective approach of combining carrier mobility promotion and strengthened phonons scattering to simultaneously improve electrical and thermal transport properties is demonstrated. For the p-type YbZn2Sb2with InSb nanoinclusions, the Hall mobility is effectively enhanced by InSb in the whole measured temperature, from 56 cm2V−1s−1to 162 cm2V−1s−1at 300 K. Meanwhile, the carrier density optimization by tuning Yb vacancies leads to 46% improvement in the Seebeck coefficient, overcoming the negative contribution from InSb. Moreover, with the help of interface scattering caused by nanoinclusions, the lattice thermal conductivity is reduced by 45% at 720 K. As a result, the thermoelectric figure of meritZTis enhanced nearly a factor of three. We believe our method provides a “combined strategy” to enhance thermoelectric performance of YbZn2Sb2based compounds and should be applicable to other thermoelectric materials.