晶格平面化推进了高效的SnSe晶体热电
Dongrui Liu1, Dongyang Wang2, Tao Hong1
1School of Materials Science and Engineering, Beihang University, Beijing 100191, China.
Science (New York, N.Y.)
|May 25, 2023
概括
研究人员设计了锡化物 (SnSe) 晶体,提高了废热回收和固态冷却的热电性能. 铜注显著提高了SnSe的效率和冷却能力.
科学领域:
- 材料科学
- 固态物理
- 纳米技术
背景情况:
- 热电技术对于废热回收和固态冷却应用至关重要.
- 锡化物 (SnSe) 晶体对热电发电和皮尔蒂埃冷却具有前景.
- 在SnSe的缺陷显著影响其运输特性,需要缺陷工程策略.
研究的目的:
- 为SnSe晶体的缺陷工程开发一个格子简化策略.
- 提高SnSe的热电性能,用于实际应用.
- 研究铜 (Cu) 兴奋剂对SnSe晶体特性的影响.
主要方法:
- 开发了SnSe中缺陷工程的格子简化策略.
- 引入铜 (Cu) 填补锡 (Sn) 的空缺,修改缺陷散射.
- 描述了改造的SnSe晶体的运输特性,功率因子和无维度功率 (ZT).
主要成果:
- 通过减少SnSe中的缺陷散射,铜剂增强了载体的移动性.
- 每平方克尔文每厘米的功率超过100微瓦.
- 在300克尔文时获得了大约1.5的无维度值 (ZT),平均ZT在300和773克尔文之间为2.2.
- 在温度差异 (ΔT) 为 300 克尔文时,单脚热电转换效率为 12.2%.
- 在环境温度下实现了61.2凯尔文的最大佩尔蒂尔冷却温度差异 (ΔTmax).
结论:
- 网格简化和铜剂有效地设计了SnSe的缺陷,增强了热电性质.
- 改进的SnSe晶体具有实际废热回收和电子冷却应用的巨大潜力.
- 这项研究为优化SnSe热电材料的商业用途提供了途径.
相关概念视频
02:54Trends in Lattice Energy: Ion Size and Charge
An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure of the strength of this attraction. The lattice energy (ΔHlattice) of an ionic compound is defined as the energy required to separate one mole of the solid into its component gaseous ions. For the ionic solid sodium chloride, the lattice energy is the enthalpy change of the process:
01:27Lattice Energies of Ionic Crystals
Lattice energy represents the energy released when gaseous cations and anions combine to form an ionic solid, reflecting the strength of electrostatic interactions within the crystal. This process is fundamentally governed by Coulombic attraction between oppositely charged ions, where the potential energy varies inversely with the interionic distance and directly with the product of ionic charges. As ions approach one another, the electrostatic energy becomes increasingly negative, indicating a...
01:26Imperfections in Crystal Structure: Stoichiometric Point Defects
Schottky defects arise when some lattice points in a crystal, such as those in NaCl, remain unoccupied, creating lattice vacancies without disturbing the overall electrical neutrality of the crystal. This defect is common in ionic crystals where the positive and negative ions are similar in size, as seen in sodium chloride and cesium chloride. The presence of Schottky defects enables the crystal to conduct electricity to a small extent through an ionic mechanism. Electric fields cause nearby...