Extending the temperature range of the Cmcm phase of SnSe for high thermoelectric performance

• 成果类型: Article
• 署名作者: Gao, Tian; Wen, Yi; Bai, Shulin; Su, Lizhong; Shi, Haonan; Liu, Rong; Wang, Sining; Hu, Yixuan; Liu, Shibo; Liu, Dongrui; Liu, Shan; Liang, Chao; Feng, Xiaokun; Wang, Xiaoqian; Qin, Yongxin; Gao, Xiang; Qin, Bingchao; Chang, Cheng; Bai, Peikang; Zhao, Li-Dong
• 署名单位: Beihang University; Taiyuan University of Science & Technology; Beihang University
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-8075; 1095-9203
• DOI: 10.1126/science.adt0831
• 发表日期: 2025-12-18
• 页码: 1266-1271
• 关键词: n-type snse; EFFECTIVE-MASS; power-generation; RECENT PROGRESS; approximation; transport; crystals; DYNAMICS; charge

摘要

Thermoelectric power generation requires high dimensionless figure of merit ZT across broad temperatures. The two-dimensional phonon and three-dimensional charge transports enable n-type-Pnma tin selenide (SnSe) crystals to show a peak ZT of similar to 3.0 at 748 kelvin. In this work, we focused on the high-symmetry Cmcm phase to boost two-dimensional phonon and three-dimensional charge transports and extended the high-performance (ZT similar to 3.0) plateau. By simultaneously broadening the Cmcm-phase stability window and enhancing lattice symmetry through lead alloying, we extended the high performance from a single temperature point to a wide temperature range of similar to 250 kelvin in rock salt-like Cmcm SnSe crystals rendered n-type through chlorine doping. An average ZT of similar to 3.0 was achieved between 673 and 923 kelvin, with a conversion efficiency of similar to 19.1% under a temperature difference of similar to 572 kelvin.