表面粗糙钠掺杂硒化锡的含能材料爆燃制备及热电性能研究

Thermoelectric modules could convert part of waste heat to electricity and reduce heat accumulating, which renders them as one of the potential functional materials for clean energy and environmental applications. However, the conversion efficiency of thermoelectric materials is too low to meet the practical application needs. Introducing nanostructures at different length scales (roughness, point defects) and element doping can highly enhance the phonon scattering and increase carrier concentration, leading to low thermal conductivity and high electrical conductivity, respectively, which will remarkably improve the thermoelectric performance. The project plans to fabricate Na doped SnSe nanomaterials with rough surface via energetic material NaN3 deflagration, which will generate highly reactive Na nanoclusters and N radicals as well as local high temperature and pressure environment to achieve surface etching at the nanoscale and Na doping. Rough surface can reduce thermal conductivity by enhancing phonon scattering while Na doping will increase carrier concentration to improve electrical conductivity. The synergistic regulation of electrical and phonon conductivity in Na doped rough SnSe materials will significantly improve the thermoelectric performance. The project plans to investigate the preparation technology, relationship between structure characteristics and thermoelectric properties of Na dope SnSe with rough surface via energetic materials deflagration to lay a foundation for synthesis and study of high performance thermoelectric materials.

热电材料可将生产生活中的部分废热转化为电能而减缓热量的积累，是解决目前能源和环境问题的潜在功能材料之一。然而，目前热电材料的转换效率较低，远不能满足实际应用需要。通过构建粗糙表面、点缺陷等纳米结构以增加声子散射进而降低热导率，掺杂元素以提高载流子浓度及电导率，可有效提高材料的热电性能。本研究课题以含能材料NaN3为Na源，将其与SnSe纳米材料混合后触发爆燃反应，使其产生局部高温高压的极端物理环境和高能N自由基及单质Na粒子流，对SnSe表面进行微纳尺度蚀刻造坑/孔，以实现表面粗糙化和Na掺杂，从而有效降低热导率并提高电导率，通过对材料电声输运性能的协同调控，以大幅度提高材料的热电性能。本课题就这种含能材料爆燃法制备表面粗糙钠掺杂SnSe热电材料的制备工艺、结构特征与热电性能关系进行研究，为高性能热电材料的研究奠定基础。

热电材料可将生产生活中的部分废热转化为电能而减缓热量的积累，是解决目前能源和环境问题的潜在功能材料之一。然而，目前热电材料的转换效率较低，远不能满足实际应用需要。通过构建粗糙表面、点缺陷等纳米结构以增加声子散射进而降低热导率，掺杂元素以提高载流子浓度及电导率，可有效提高材料的热电性能。本项目提出了利用含能材料NaN3爆燃一步快速制备表面粗糙Na掺杂SnSe材料的研究思路。在项目实施过程中，系统研究了NaN3爆燃特性，获得了NaN3爆燃提升SnSe热电性能的工艺条件，实现了一步快速表面粗糙化和Na掺杂，从而有效降低热导率并提高电导率，通过对材料电声输运性能的协同调控，有效提高了SnSe材料的热电性能。本课题研究成果为高性能热电材料的制备提供了新的途径，也为其他先进功能材料的制备提供了科学指导。