Pb掺杂对Bi0.5Sb1.5Te3热电材料性能的影响  

Effects of Pb Doping on Properties of Bi0.5Sb1.5Te3 Thermoelectric Materials

作　　者：马正青[1] 王诗野 杨明杰 MA Zhengqing;WANG Shiye;YANG Mingjie(College of Material Science and Engineering,Central South University,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院

出　　处：《昆明理工大学学报（自然科学版）》2019年第6期25-30,共6页Journal of Kunming University of Science and Technology(Natural Science)

基　　金：长沙市科技计划项目(kq1801064)

摘　　要：采用真空熔炼、高能球磨、冷压成型和气氛烧结工艺制备了Pb掺杂的P型Bi0.5Sb1.5Te3块体热电材料.利用X射线衍射仪(XRD)、扫描电镜(SEM)、热电参数测试系统(Namicro-3)、激光热导仪(LFA-467)和DSC等测试技术,研究了Pb掺杂对Bi0.5Sb1.5Te3热电材料的物相组成、表面形貌和热电性能的影响.结果表明:Pb掺杂能够抑制单质Te的析出及Pb原子取代Bi/Sb原子的位置,产生空穴,载流子浓度增大,电导率升高,Pb原子半径与Bi/Sb原子半径不同,增加晶格畸变,降低热导率,从而有效提高Bi0.5Sb1.5Te3热电材料的综合性能.在300K时,Pb0.003Bi0.497Sb1.5Te3的电导率为8.35×104 S/m,塞贝克系数为179μV/K,热导率为0.716 W/(m·K),热电优值达到1.122.Pb doped P-type Bi0.5Sb1.5Te3 bulk thermoelectric materials were prepared by vacuum melting, high energy ball milling, cold press forming and atmosphere sintering. The phase, surface morphology and thermoelectric properties of thermoelectric materials were tested by X-ray diffraction(XRD), scanning electron microscopy(SEM), thermoelectric parameter test system(Namicro-3), laser flash method(LFA-467)and DSC. The results showed that Pb doping could effectively inhibit the precipitation of elemental Te, and the Pb atom replaced the position of the Bi/Sb atom, generated holes, and increased carrier concentration and electrical conductivity. Because Pb atomic radius was different from Bi/Sb atomic radius, the increase in lattice distortion reduced thermal conductivity and improved the comprehensive thermoelectric properties of Bi0.5Sb1.5Te3 thermoelectric material.At 300 K, the conductivity of the Pb0.003Bi0.497Sb1.5Te3 sample was 8.35×104 S/m, Seebeck coefficient was 179 μV/K, thermal conductivity was 0.716 W/(m·K), and the thermoelectric value reached 1.122.

关 键 词：BI2TE3 热电材料 快速冷却 机械球磨 

分 类 号：TB34[一般工业技术—材料科学与工程]