Investigating the thermoelectric performance of n-type SnSe: the synergistic effect of NbCl5doping and dislocation engineering
Investigating the thermoelectric performance of n-type SnSe: the synergistic effect of NbCl5doping and dislocation engineering
复制标题
研究n型SnSe的热电性能：NbCl(5)掺杂和位错工程的协同效应
DOI：
10.1039/d0tc02959a
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发表时间：
2020-10-14
影响因子：
6.4
通讯作者：
Jiang, Jun
中科院分区：
文献类型：
--
作者：
Cai, Jianfeng;Zhang, Yan;Jiang, Jun
硒化锡(SnSe)具有良好的电子结构和较低的导热系数，是一种很有前途的热电材料。本工作采用真空熔炼和热压法制备了新型掺杂NbCl5的n型多晶SnSe(0.95)，得到了织构结构和热电性能各向异性的n型多晶SnSe。通过X射线衍射仪、扫描电子显微镜和X射线光电子能谱对样品的晶相、微观结构和成分进行了分析。透射电子显微镜观察表明，我们的多晶SnSe0.95中存在大量的位错和纳米晶颗粒，与以前的报道相比，这导致了更低的导热系数和更好的力学性能。沿平行和垂直于高压压强方向的电输运测量表明，载流子的散射行为是复杂的，并且对整体热电性能有很大的影响。在790K时，0.5%NbCl5掺杂的SnSe(0.95)样品的ZT值达到最大值1.22，超过了大多数其他卤化物掺杂的n型多晶SnSe系统。
Tin selenide (SnSe) is a promising thermoelectric material because of its advantageous electronic structure and low thermal conductivity. In this work, n-type polycrystalline SnSe(0.95)doped with a new dopant NbCl(5)was prepared using vacuum melting and hot-pressing (HP) methods, which resulted in a textured microstructure and anisotropic thermoelectric performance. Several state-of-the-art characterization studiesviaXRD, SEM, and XPS were conducted to analyze the crystal phase, microstructure, and composition of the samples. The TEM observation showed that large amounts of dislocations and nanocrystalline grains existed in our polycrystalline SnSe0.95, which resulted in lower thermal conductivity and better mechanical performance compared to previous reports. The electrical transport measurements along the parallel and perpendicular directions to the HP pressure revealed that the scattering behavior of charge carriers was complex and had a profound effect on the overall thermoelectric properties. Finally, a maximumZTvalue of 1.22 at 790 K was attained in the 0.5% NbCl5-doped SnSe(0.95)sample, which exceeds most of the n-type polycrystalline SnSe systems doped with other halides.