AgSb_(0.96)Q_(0.04)Te_(2)(Q=Ge、Zn、Cd、Sn、Pb)载流子输运行为调控与热电性能优化  

Control of Carrier Transport Behavior and Optimization of Thermoelectric Performance in AgSb_(0.96)Q_(0.04)Te_(2)(Q=Ge,Zn,Cd,Sn,Pb)

作　　者：李若琰 葛邦治 周重见 LI Ruoyan;GE Bangzhi;ZHOU Chongjian(State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China)

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《铸造技术》2024年第9期880-886,共7页Foundry Technology

基　　金：凝固技术国家重点实验室基金(2023-QZ-01);国家自然科学基金(22379124)。

摘　　要：AgSbTe_(2)由于其固有的极低热导率与较大的塞贝克系数,在中低温发电应用中具有很大的潜力。但是由于本征低载流子浓度和阳离子的无序性导致材料的低电荷迁移率,并且二者存在强烈的耦合关系,AgSbTe_(2)体系电学性能一直未能有效提升。本文通过向Sb离子位点掺杂二价元素,制备了一系列AgSb_(0.96)Q_(0.04)Te_(2)(Q=Zn、Sn、Ge、Pb、Cd)热电化合物,成功实现了载流子浓度与载流子迁移率之间的解耦,进而大幅提升了AgSbTe_(2)热电性能。研究发现,Pb元素的掺杂可优化p型AgSbTe_(2)的载流子浓度,同时提升载流子迁移率,进而大幅提升电学性能。相应的最大电导率和功率因子在548 K时分别达到229 S/cm和15.1μW/(cm·K2),相比未掺杂AgSbTe_(2)样品分别提升了108%和44%。最终,AgSb_(0.96)Pb_(0.04)Te_(2)晶体在298与548 K下zT值分别达到了0.60与1.53,且在298~598 K内平均zT达1.10。AgSbTe_(2) has great potential for power generation applications from low to medium temperatures because of its inherent low thermal conductivity with a large Seebeck coefficient.However,the electrical properties of the AgSbTe_(2) system have not been effectively improved due to the intrinsically low carrier concentration and the disorder of the cations,which are physically coupled and lead to the low charge mobility of the material.In this work,a series of AgSb_(0.96)Q_(0.04)Te_(2)(Q=Ge,Zn,Cd,Sn,Pb)thermoelectric compounds were prepared by doping divalent elements into Sb ion sites,successfully achieving decoupling between the carrier concentration and carrier mobility,thereby greatly improving the thermoelectric performance of AgSbTe_(2).The results show that doping with Pb can optimize the carrier concentration of p-type AgSbTe_(2) without decreasing carrier mobility,thereby greatly improving the electrical performance.The maximum conductivity and power factor for AgSb_(0.96)Pb_(0.04)Te_(2) reach 229 S/cm and 15.1μW/(cm·K2)at 548 K,respectively,which are 108%and 44%greater than those of the intrinsic sample.The resulting zT value of the AgSb0.96Pb0.04Te_(2) crystal reaches 0.60(298 K)and 1.53(548 K),contributing a high average zT of~1.10 from 298 K to 598 K.

关 键 词：AgSbTe_(2) 阳离子位元素掺杂 功率因子 热电性能 

分 类 号：TG132[一般工业技术—材料科学与工程] TB34[金属学及工艺—合金]