通过引入纳米结构以调控和优化热电性能是目前热电材料研究重要领域之一，但其精细结构表征以及结构调控性能的微观物理机制方面仍是欠缺的。本项目以Bi2Te3和Sb2Te3掺杂的GeTe基赝层状热电材料为研究对象，结合先进球差校正电子显微镜分析技术和原位电镜实验手段模拟表征材料在退火和加热服役条件下结构的转变过程，并实时观察材料中多尺度微米畴、纳米畴和本征Ge空位缺陷结构的动态形核、迁移、生长和结构重构等过程。通过对动态温度和时间演变过程中纳米结构的类型、分布、密度以及原子构型进行定量统计和理论计算，获得不同类型纳米结构在不同温度及时间演化阶段的具体结构特征，从而由特征微结构的结构演化出发解释GeTe基热电材料在退火处理与加热服役过程中Seebeck系数、电导率以及热导率的变化规律及物理机制，为一系列具有结构纳米化特征热电材料的性能优化和机理研究提供有价值的参考。

The introduction of nanostructures into thermoelectric materials is becoming an important research area for the optimization of thermoelectric materials. A number of works have been done in the enhancement of macroscopic electrical and thermal properties of thermoelectric materials based upon nanostructures. However, very few researches are related to their microscopic structures and underlying physical mechanism. In this proposal, by combining the advanced aberration-corrected transmission electron microscopy (TEM), and in-situ TEM, we will study the dynamic nucleation, migration, growth and structure reconstruction of hierarchical micro/nano-domains and intrinsic Ge vacancies in Bi2Te3 or Sb2Te3 doped GeTe materials with different thermal processes and at a series of temperatures. By means of theoretical simulations, we will obtain a deeper understanding of the nanostructures as well as their thermodynamics and kinematics, and establish a model of the evolution of micro/nano-structures, which can explain the macroscopic heat and electrical properties of nanostructured thermoelectric materials.