基于GeSe的三维结构的面体化合物中的二维类似的声子,具有出色的热电性能
Jingjing Cui1,2, Chenghao Xie1,2, Weiwei Hu1
1State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan, Hubei 430070, People's Republic of China.
ACS applied materials & interfaces
|July 20, 2024
概括
研究人员开发了新的化 Telluride (GeSe0.65Te0.35) 半导体. 体结构通过解电荷和声子传输实现了1.1的热电功率 (ZT) 峰值.
科学领域:
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
- 热电学是一种热电学.
背景情况:
- 电荷和声子传输的合阻碍了热电性能.
- 开发具有脱运输的新材料对于高效的热电技术至关重要.
研究的目的:
- 设计和合成新的窄间隙半导体,具有脱的电荷和声子传输.
- 研究基于GeSe0.65Te0.35 (GST) 的材料中的结构-属性关系.
- 通过结构工程和兴奋剂来提高热电性能.
主要方法:
- 合成GeSe0.65Te0.35的分层六角形 (H-GST) 和非分层圆角形 (R-GST) 阶段.
- 结构性,热性和电传输性质的表征.
- 使用低温特异热和声光谱计算对声行为的分析.
- 在升高的温度下,Sb兴奋剂以稳定面相.
主要成果:
- 与H-GST相比,R-GST展示了一个3D网络结构,具有更高的加权移动性.
- R-GST显示了非常低的晶格导热率 (∼0.5 W m-1 K-1 在523 K) 由于由偏离中心的Ge原子和铁电不稳定性诱导的2D类声子传输.
- Sb 注 (1 mol %) 抑制了相变,使得工作温度更高.
- 在Sb添加剂的R-GST中,达到623K的峰值热电功率 (ZT) 达到了1.1个,比GeSe.
结论:
- 体GeSe0.65Te0.35结构促进了脱电荷和声子传输,从而提高了热电特性.
- 离中心的原子和由此产生的铁电不稳定性是实现低晶格导热率的关键.
- 这项研究表明,通过探索具有离心原子的化合物来设计高性能热电材料的可行策略.
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