通过控制空置人口来提高SnSe的热电性能
Ji-Eun Lee1,2,3,4, Kyoo Kim2,5,6, Van Quang Nguyen7
1Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
Nano convergence
|July 7, 2023
概括
在锡化物 (SnSe) 增长期间控制空位度调整了其电子带结构. 这种优化通过操纵价值带的最大值来提高热电性能,为材料设计提供了新的途径.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 热电材料 热电材料
背景情况:
- 锡化物 (SnSe) 的热电性能严重依赖于其低能电子带结构.
- 在一个狭窄的能量窗口内,高密度的状态,由多谷带最大值 (VBM) 产生的,是SnSe热电特性的关键.
研究的目的:
- 调查锡空位度与SnSe. 的电子带结构之间的关系.
- 为了确定价值带最大 (VBM) 转移和热电性能之间的相关性.
- 探索样本生长条件作为优化内在缺陷引起的热电特性的一种方法.
主要方法:
- 角度分辨率光辐射光谱学 (ARPES) 测量.
- 第一原则计算.第一原则计算.
- 在样本生长期间控制冷却速率的变化,以调整锡空置度.
主要成果:
- 在SnSe中,VBM的结合能直接受到空位的数量的影响.
- VBM转移与热电功率因子的变化精确相关.
- 电荷载体的有效质量在很大程度上不受锡空位度变化的影响.
结论:
- 低能电子带结构,特别是VBM,与孔合SnSe的高热电性能密切相关.
- 样本生长条件,特别是冷却速度,提供了一种可控制的方法来设计内在缺陷引起的热电性能.
- 这项研究为优化SnSe热电特性提供了一条可行的途径,而不需要增长后处理.
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