碲化铋基热电材料中的类施主效应是材料粉碎烧结和热变形加工中产生的一种引起施主浓度显著上升的普遍现象，也是导致粉末烧结n型碲化铋基多晶材料室温热电性能低于区熔定向凝固材料的重要原因之一。但关于类施主效应的“非基面滑移-空位对-反位缺陷复合”解释缺乏充分依据，形成类施主效应的微观机制尚未清晰。本项目提出围绕碲化铋基热电材料中类施主效应的微观形成机制、影响因素及其作用规律和有效控制等关键科学问题，开展变形过程中晶体缺陷的形成转变与相互作用的热力学分析和高分辨电镜原位观察研究，材料成分和制备过程对类施主效应影响规律的系统研究，以求揭示类施主效应的形成机制，阐明其影响规律，实现其有效控制，并在此基础上提出进一步优化n型碲化铋基热电材料室温性能的可行性方案。

The donor concentration of a bismuth telluride based thermoelectric material could be significantly increased after the pulverizing-sintering processes or hot-deformation of the material, which, called donor-like effect, is one of the main causes of the lower thermoelectric properties at room temperature of sintered n-type bismuth telluride materials than the zone-melting materials. The microstructural mechanism of the donor-like effect is not clear till now, and the only assumption of “nonbasal slip - vacancy pair” is lack of evidence yet. Focusing on the microstructural mechanism, influence and control of the donor-like effect, we propose here a deepgoing and comprehensive investigation on the donor-like effect in bismuth telluride based materials, including the thermodynamics analyses and high-resolution electron microscopy in-situ observation of the formation, transformation and interaction of crystal defects during deformation of the materials, the study of the influence and control of alloy elements and preparation processes on the donor-like effect, and then the development of the feasible route for improving the room temperature thermoelectric properties of n-type bismuth telluride based materials.