Siddique Suniya, Gong Yaru, Abbas Ghulam, Yaqoob Manzar Mushaf, Li Shuang, Zulkifal Shahzada, Zhang Qingtang, Hou Yunxiang, Chen Guang, Tang Guodong
MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials Technology, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, P. R. China.
Applied Physics, Division of Materials Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå 97187, Sweden.
ACS Appl Mater Interfaces. 2022 Jan 26;14(3):4091-4099. doi: 10.1021/acsami.1c20549. Epub 2022 Jan 9.
SnSe crystals have gained considerable interest for their outstanding thermoelectric performance. Here, we achieve excellent thermoelectric properties in SnPbZnSe crystals via valence band convergence and point-defect engineering strategies. We demonstrate that Pb and Zn codoping converges the energy offset between multiple valence bands by significantly modifying the band structure, contributing to the enhancement of the Seebeck coefficient. The carrier concentration and electrical conductivity can be optimized, leading to an enhanced power factor. The dual-atom point-defect effect created by the substitution of Pb and Zn in the SnSe lattice introduces strong phonon scattering, significantly reducing the lattice thermal conductivity to as low as 0.284 W m K. As a result, a maximum value of 1.9 at 773 K is achieved in SnPbZnSe crystals along the -plane direction. This study highlights the crucial role of manipulating multiple electronic valence bands in further improving SnSe thermoelectrics.
SnSe晶体因其出色的热电性能而备受关注。在此，我们通过价带收敛和点缺陷工程策略在SnPbZnSe晶体中实现了优异的热电性能。我们证明，Pb和Zn共掺杂通过显著改变能带结构来收敛多个价带之间的能量偏移，有助于塞贝克系数的提高。载流子浓度和电导率可以得到优化，从而提高功率因数。SnSe晶格中Pb和Zn的取代所产生的双原子点缺陷效应引入了强烈的声子散射，将晶格热导率显著降低至0.284 W m K。结果，SnPbZnSe晶体在773 K时沿c平面方向实现了1.9的最大值。这项研究突出了操纵多个电子价带在进一步改善SnSe热电材料方面的关键作用。
