Investigating the thermoelectric performance of n-type SnSe: the synergistic effect of NbCl5 doping and dislocation engineering. Issue 38 (10th September 2020)

• Record Type: Journal Article
• Authors: Cai, Jianfeng; Zhang, Yan; Yin, Yinong; Tan, Xiaojian; Duan, Sichen; Liu, Guo-Qiang; Hu, Haoyang; Xiao, Yukun; Ge, Zhenhua; Jiang, Jun
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 38(2020)
• Page Start: 13244
• Page End: 13252
• Publication Date: 2020-09-10
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0tc02959a
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : NbCl5 doped SnSe0.95 to achieve carrier concentration adjustment and dislocation engineering in order to improve the ZT value. Abstract : Tin selenide (SnSe) is a promising thermoelectric material because of its advantageous electronic structure and low thermal conductivity. In this work, n-type polycrystalline SnSe0.95 doped with a new dopant NbCl5 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 studies via XRD, 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 maximum ZT value of 1.22 at 790 K was attained in the 0.5% NbCl5 -doped SnSe0.95 sample, which exceeds most of the n-type polycrystalline SnSe systems doped with other halides.