高热电性能在面的GeSe-LiBiTe
Jinfeng Dong1, Yukun Liu2, Zhi Li2
1School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.
Journal of the American Chemical Society
|June 13, 2024
概括
本研究介绍了使用LiBiTe2合金来提高化物 (GeSe) 的热电性能的晶体结构演变策略. 这种方法实现了高注,低导热率和1.3的峰值ZT.
科学领域:
- 材料科学
- 固态物理
- 热电器
背景情况:
- 德化物 (GeSe) 显示了热电应用的潜力,但受限于可用性挑战.
- 优化载体度对于提高热电功率 (ZT) 是至关重要的.
研究的目的:
- 开发具有增强热电性质的高度合的GeSe的晶体结构演变策略.
- 研究 LiBiTe2 合金对 GeSe 晶体结构,电子带结构和热电性能的影响.
主要方法:
- 将GeSe与LiBiTe2合金,以诱导晶体结构的演变 (从方形到立方形).
- 电子带结构和载体度的表征
- 在温度范围内测量格子导热率和热电功率 (ZT).
主要成果:
- 在GeSe-LiBiTe2合金中稳定面 (R3m) 和立方 (Fm3̅m) 阶段.
- 对汇聚的多谷价值带 (L 和 Σ 带) 的观察导致了高载体度 (~10^20 cm^-3) 和增强的功率因子.
- 由于声子散射机制,实现了超低的晶格导热率 (0.6-0.5 W m^-1 K^-1).
- 在0.9GeSe-0.1LiBiTe2中,最大ZT为1.1-1.3在723K,平均ZT大于0.8 (400-723K).
结论:
- 通过合金的晶体结构工程是一种有效的策略,可以克服GeSe的可配限.
- 对于高性能热电材料,GeSe-LiBiTe2系统具有显著的潜力.
- 这项工作为定制基于GeSe的化合物的热电性能提供了途径.
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