透射电镜在热电材料中的应用

Application of Transmission Electron Microscope in Thermoelectric Materials

热电材料可以实现电能与热能之间的直接相互转化,有希望用来应对即将到来的能源危机,但较低的能源转换效率限制了它的广泛应用。材料的热电特性与其微观结构(如点缺陷、位错、界面、第二相粒子、孔洞等)密切相关,对热电材料进行精密微观结构表征不仅对于深刻理解材料热电性质至关重要,而且有助于设计具有所需性能的新材料。从电热输运性能计算公式出发,阐明了热电材料结构与性能的相关性,展示了如何通过结构控制调控热电材料电热输运性能,综述了透射电镜在热电材料研究中的应用,包含对原子、纳米和介观全尺度缺陷结构表征。

Thermoelectric materials that realize the direct energy conversion between heat and electricity, have been considered as promising alternatives to meet the challenges of the global energy dilemma. However, the low energy conversion efficiency limits its wide application. The properties of thermoelectric materials are closely related to its microstructure(such as point defects, dislocations, interfaces, second phase particles, pores, etc.), the precise microstructure characterization of thermoelectric materials not only is crucial to profoundly understanding the material itself, but also helps to design new materials with properties. In this review, we illustrate the structure-property correlations from the perspective of calculation formula of electrical and thermal transport performance, and show how to tune the electrical and thermal transport performance of thermoelectric materials through structure control.The application of transmission electron microscope in thermoelectric materials is reviewed, including the characterization of atomic, nano and mesoscopic full-scale defect structures.