代价键和多邦轨道之间的相互作用使SnTe热电的设计成为可能
Guodong Tang1, Yuqi Liu2, Xiaoyu Yang3
1National Key Laboratory of Advanced Casting Technologies, MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials Technology, Engineering Research Center of Materials Behavior and Design, Ministry of Education, Nanjing University of Science and Technology, Nanjing, 210094, China. tangguodong@njust.edu.cn.
Nature communications
|October 23, 2024
概括
我们发现Sn-s在SnTe中的状态通过增加状态密度来增强热电性能. 这导致被确定为SnTe的优质剂,实现了1.15.5的ZT记录.
科学领域:
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
- 化学 化学 化学
背景情况:
- 优化热电材料需要精确控制电子带结构.
- 了解接近费米水平的电子状态上的剂效应是调带结构的关键.
研究的目的:
- 研究Sn-s状态在SnTe的价值带结构中的作用.
- 建立一个设计规则,用于识别热电材料的有效剂.
- 为了提高SnTe.Te的热电性能.
主要方法:
- 电子带结构和状态密度的分析.
- 在价值带最大值处识别元价值键和轨道相对称.
- 基于轨道重叠和能量差异的选剂.
- 基于SnTe的材料的实验性兴奋剂,合金和表征.
主要成果:
- 由于元价结合,Sn-s状态对SnTe价值带顶部的状态密度有显著的贡献.
- 建立了一个设计规则,优先考虑dopant s-和宿主 Te p-状态之间的最大化的空间和最小化的能量重叠.
- (Al) 被确定为提高SnTe.状态的局部密度的有效补充剂.
- 一种基于SnTe的材料 (Sn0.8Al0.08Sb0.15Te-4%AgBiTe2) 实现了创纪录的平均ZT为1.15 (300873 K) 和ZT为0.36 (300 K).
结论:
- SnTe的电子结构,特别是Sn-s状态的贡献,对于其热电性质至关重要.
- 开发的设计规则为发现新的剂以改善热电材料提供了一条途径.
- 结合Al兴奋剂,Sb兴奋剂,AgBiTe2合金和脱位工程,显著提高了SnTe的热电性能.
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