在PbTe中纳:可溶性,频段收,相极限映射和热电性质
Priyanka Jood1, James P Male2, Shashwat Anand2
1Global Zero Emission Research Center, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.
Journal of the American Chemical Society
|August 14, 2020
概括
在电化物 (PbTe) 热电器中超过可溶性极限可以提高性能. 通过优化带结构和抑制不必要的导电,更高的增强了热电功率 (zT).
科学领域:
- 材料科学
- 固态物理
- 热电能转换
背景情况:
- 热电材料将热转化为电力,其中化 (PbTe) 是一个关键的p型材料.
- 优化PbTe热电常常涉及兴奋剂,Pb0.98Na0.02Te是一种常见的高性能矩阵.
研究的目的:
- 调查Pb1-xNaxTe的热电性能,其含量 (x) 超过典型的可溶性极限 (x > 0.02).
- 阐明这些过度合材料中增强热电功率 (zT) 的机制.
主要方法:
- Pb1-xNaxTe的计算建模和实验合成 (0.01 ≤ x ≤ 0.04).
- 高温X射线衍射和霍尔载体度测量
- 分析带结构的融合和双极导电抑制.
主要成果:
- 在x>0.02的高温下观察到增强的Na溶性,Na进入晶格,但被电补偿.
- 在PbTe中,由于Na度较高,L和S值带之间的频段收.
- 抑制双极导电和增加西贝克系数,导致zT接近Pb0.96Na0.04Te.
结论:
- 在PbTe中超出可溶性极限的过量Na可以显著提高热电性能.
- 一个相图的方法有助于理解溶解性,并指导高性能化PbTe的可重复合成.
- 与Pb0.98Na0.02Te相比,Pb0.96Na0.04Te为优化p型PbTe热电提供了一个优越的起点.
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