High-performance near-room-temperature n-type Bi_(2)Te_(3)-based thermoelectric alloys with superior mechanical properties  

高力学强度高近室温热电性能的N型Bi_(2)Te_(3)基合金

作　　者：Jiaying Liu Feng Liu Yuzheng Li Boyang Ying Yongqing Wu Zefeng Tang Yiqi Cao Tiejun Zhu Chenguang Fu 刘佳莹;刘锋;李昱征;应博阳;吴永庆;唐泽丰;曹一琦;朱铁军;付晨光

机构地区：[1]State Key Laboratory of Silicon and Advanced Semiconductor Materials,School of Materials Science and Engineering,Zhejiang University,Hangzhou 310058,China [2]Institute of Wenzhou,Zhejiang University,Wenzhou 325006,China [3]Thermoelectricity Technology Center,Hangzhou Dahe Thermo-magnetics Co.,Ltd.,Hangzhou 310053,China [4]Department of Materials Engineering,Taizhou University,Taizhou 318000,China

出　　处：《Science China Materials》2025年第3期920-927,共8页中国科学(材料科学)(英文版)

基　　金：supported by the Key Research and Development Program of Zhejiang Province(2022C01131);the Zhejiang Provincial Natural Science Foundation of China(LD22E020005,LTY20E010001);the 111 Project(B16042).

摘　　要：Hot deformation is an important technique for fabricating high-strength n-type Bi2Te3-based thermoelectric(TE)alloys.However,the poor controllability of the oxygeninduced donor-like effect during the fabrication process often results in an overhigh carrier concentration,significantly worsening the near-room-temperature TE performance.Here,by maximumly avoiding the oxygen-induced donor-like effect,the carrier concentration of n-type TeI_(4)-doped Bi_(2)Te_(2.7)Se_(0.3) can maintain nearly the optimal one during the repetitive hot deformation processes while the enhanced texture contributes to higher carrier mobility.Moreover,the hot deformationinduced dislocations and local distortions are conducive to lowering the phonon transport.Consequently,a high zT of 1.0 and a large bending strength of 122 MPa are simultaneously achieved at 300 K.Additionally,a 23-pair TE cooling module of 8.20×6.10×1.65 mm^(3) was fabricated,which shows a maximum temperature difference of 82 K at the hot-end temperature of 350 K.These results highlight the crucial role of controlling the oxygen-induced donor-like effect in achieving high-performance near-room-temperature n-type Bi2Te3-based TE alloys.热变形是制备具有高强度N型Bi_(2)Te_(3)基热电材料的重要手段之一.然而,氧诱导类施主效应的发生会大大增加制备过程中的不可控性,可能导致电子浓度过高,从而严重恶化材料近室温热电性能.本文通过最大限度地避免氧诱导的类施主效应,使得N型TeI_(4)掺杂Bi_(2)Te_(2.7)Se_(0.3)样品的电子浓度在多次热变形的过程中依旧保持在最优载流子浓度区间,同时明显增强的织构有助于其迁移率的提升.此外,热变形过程中引入的位错、局域应变等不仅会有效阻碍声子的输运,还会提高材料的力学性能.最终,在300 K时zT值达1.0,并且抗弯强度高达122 MPa.基于以上材料制作了一个23对的微型热电制冷模块.当热端温度为350 K时,最大制冷温差达82 K.以上结果表明控制氧诱导的类施主效应在实现近室温高热电性能N型Bi_(2)Te_(3)基合金中具有重要意义.

关 键 词：bismuth tellurides donor-like effect near-room temperature thermoelectric materials hot deformation 

分 类 号：TG1[金属学及工艺—金属学]