通过晶体结构修改实现p型SnSe的高热电性能
Bingchao Qin1, Dongyang Wang1, Wenke He1
1School of Materials Science and Engineering , Beihang University , Beijing 100191 , China.
Journal of the American Chemical Society
|December 14, 2018
概括
研究人员通过添加 (Te) 来提高锡化物 (SnSe) 的热电性能. 这种修改实现了1.6的ZT值,提高了热电材料的能量转换效率.
科学领域:
- 材料科学
- 固态物理
- 能源转换
背景情况:
- 锡化物 (SnSe) 因其固有的无性和多重价值带而被认为具有热电潜力.
- 优化SnSe性能对于推进热电能转换技术至关重要.
研究的目的:
- 提高p型SnSe晶体的热电功率 (ZT).
- 研究 (Te) 合金对SnSe晶体结构和热电特性的影响.
主要方法:
- 合成Te合金的SnSe晶体.
- 测量热电性质 (ZT,功率系数,西贝克系数,热导率) 从300K到793K.
- 电子定位函数计算和卡拉威模型分析.
- 使用偏差校正扫描传输电子显微镜进行结构性表征.
主要成果:
- 在300-793 K的温度范围内达到创纪录的平均ZT值为~1.6,最高ZT值为2.1在793 K.
- 观察到功率因子显著增强,在300K时达到~55μW cm-1 K-2,这归因于载体移动性增加和利的价值带.
- 由于Te合金促进了锡原子的移位和结构障碍导致了晶格导热率的降低.
结论:
- 通过优化功率因子和晶格导热性,Te合金有效地提高了SnSe的热电性能.
- 通过合金来修改晶体结构的策略为改善热电材料提供了一个有前途的途径,特别是低对称的材料.
- 这项工作为设计高效能源转换的先进热电材料提供了新的途径.
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