Evolution of the Intrinsic Point Defects in Bismuth Telluride-Based Thermoelectric Materials
Evolution of the Intrinsic Point Defects in Bismuth Telluride-Based Thermoelectric Materials
复制标题
碲化铋基热电材料本征点缺陷的演变
DOI：
10.1021/acsami.9b15198
复制
发表时间：
2019
影响因子：
9.5
通讯作者：
Xinbing Zhao
中科院分区：
文献类型：
--
作者：
Qi Zhang;Bingchuan Gu;Yehao Wu;Tiejun Zhu;Teng Fang;Yu-Xi Yang;Ji;ang Liu;Bangjiao Ye;Xinbing Zhao
在多晶碲化铋基热电材料中，机械形变诱导的类施主效应可以引入高浓度的电子，通过本征点缺陷的演化来改变热电性能。然而，这些点缺陷在样品制备过程中的演变规律仍然难以捉摸。本文从热力学和动力学的角度，结合正电子湮没测量，系统地研究了n型Bi2Te3基材料中本征点缺陷的演化规律.研究发现，不仅是机械变形，而且烧结温度是至关重要的类施主效应。机械变形可以促进阳离子空位的形成，促进类施主效应的产生，烧结过程可以为Bi反位原子克服扩散势垒提供多余的能量。这一工作有助于我们更好地理解Bi2Te3基合金中本征点缺陷的演化规律，并指导我们通过操纵本征点缺陷来控制载流子浓度。
In polycrystalline bismuth telluride-based thermoelectric materials, mechanical-deformation-induced donor-like effects can introduce a high concentration of electrons to change the thermoelectric properties through the evolution of intrinsic point defects. However, the evolution law of these point defects during sample preparation remains elusive. Herein, we systematically investigate the evolution of intrinsic point defects in n-type Bi2Te3-based materials from the perspective of thermodynamics and kinetics, in combination with positron annihilation measurement. It is found that not only the mechanical deformation but also the sintering temperature is vital to the donor-like effect. The mechanical deformation can promote the formation of cation vacancies and facilitate the donor-like effect, and the sintering process can provide excess energy for Bi antisite atoms to surmount the diffusion potential barrier. This work provides us a better understanding of the evolution law of intrinsic point defects in Bi2Te3-based alloys and guides us to control the carrier concentration by manipulating intrinsic point defects.