通过改进带退化实现高热电性能的全尺度层次结构p型PbSe合金
Gangjian Tan1, Shiqiang Hao, Songting Cai
1State Key Laboratory of Advanced Technology for Materials Synthesis and Processing , Wuhan University of Technology , Wuhan 430070 , P. R. China.
Journal of the American Chemical Society
|February 20, 2019
概括
化物 (PbSe) 与化物 (PbTe) 的等级带工程显著提高了热电性能. 这种策略提高了Seebeck系数并降低了导热率,为基于PbSe的材料实现了创纪录的ZT值.
科学领域:
- 材料科学
- 固态物理
- 热电器
背景情况:
- 化 (PbSe) 具有热电应用的潜力,但需要优化.
- 调节电子带结构对于提高热电效率至关重要.
研究的目的:
- 为了提高热电性能,对PbSe的电子带结构进行分层设计.
- 研究PbTe的合金和Cd的替代对PbSe的热电特性的影响.
主要方法:
- 将PbSe与PbTe合金,以修改价值带能量偏移 (Δ EV).
- 在 Pb 位点进行 Cd 替换,以进一步调整 Δ EV 和 Seebeck 系数.
- 对电荷传输和格子导热性的分析.
主要成果:
- 用15mol%的PbTe合金加快了PbSe中温度诱导的价值带的融合.
- 3mol%的Cd替代降低了Δ EV并增加了西贝克系数.
- 格子的导热率降低到接近无形的极限 (0.5 W m-1 K-1).
- 在900 K达到1.7的峰值ZT和Pb0.95Na0.02Cd0.03Se0.85Te0.15的平均ZT.
结论:
- 通过合金和替代等级带工程是基于PbSe的热电的有效策略.
- 与原始PbSe相比,开发的材料显著提高了热电性能.
- 这项工作为设计高性能热电材料提供了途径.
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