通过Hg和Sb编码在GeTe中的电子结构调制导致高热电性能
Paribesh Acharyya1, Animesh Das1, Raagya Arora2
1New Chemistry Unit, International Centre for Materials Science and School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur P.O., Bangalore 560064, India.
Journal of the American Chemical Society
|May 22, 2025
概括
在 (Hg) 和 (Sb) 加的化 (GeTe) 中实现了高热电性能. 这种新材料具有优化的电子结构和降低的热导率,
科学领域:
- 材料科学
- 固态物理
- 热电器
背景情况:
- 化 (GeTe) 是一个有前途的热电材料,但其性能受到高载体度和晶格导热度的限制.
- 优化电子带结构和引入中间状态是提高热电功率 (zT) 的关键策略.
研究的目的:
- 通过与Hg和Sb的配合来提高GeTe的热电性能.
- 研究Hg和Sb配合对GeTe的电子带结构和晶格导热性的影响.
主要方法:
- 合成Hg和Sb配合的GeTe.
- 热电性质的实验性表征 (西贝克系数,电导率,热导率).
- 电子带结构分析的第一原理密度功能理论 (DFT) 计算.
- 皮萨伦科分析研究状态的电子密度.
- 一个双脚热电装置的制造和测试.
主要成果:
- 在 727 K 的 Hg 和 Sb 合的 GeTe 中,达到 2.4 的热电功率 (zT).
- 补充Hg促进了价值带的融合,并引入了混合的中间距离带,增强了Seebeck系数.
- Sb codoping局部化了中间状态并改变了费米水平,进一步提升了西贝克系数.
- 在固体溶液极限以上形成的HgTe纳米沉物,显著降低了晶格导热率.
- 一个热电装置显示出一个有前途的输出功率密度为0.77W/cm2.
结论:
- 电子结构优化的协同效应和Hg和Sb配合的GeTe的晶格导热率降低导致了高的热电性能.
- 开发的材料显示出高性能热电发电应用的巨大潜力.
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