基于分步式双重调控n型(PbTe)_(1-x-y)(PbS)_(x)Sb_(2)Se_(3)_(y)体系的热电传输特性  

Thermoelectric Transport Characteristics of n-type(PbTe)_(1-x-y)(PbS)_(x)(Sb_(2)Se_(3))_(y) Systems via Stepwise Addition of Dual Components

作　　者：张岑岑 王雪[1] 彭良明[1] ZHANG Cencen;WANG Xue;PENG Liangming(CAS Key Laboratory of Mechanical Behavior and Design of Materials,Department of Modern Mechanics,School of Engineering Science,University of Science and Technology of China,Hefei 230026,China)

机构地区：[1]中国科学技术大学工程科学学院,近代力学系,材料力学行为与设计重点实验室,合肥230026

出　　处：《无机材料学报》2021年第9期936-942,共7页Journal of Inorganic Materials

摘　　要：PbTe在中温区热电材料中广受关注,然而,n型PbTe因其较低的载流子浓度和复杂的能带结构,其热电性能难以大幅提升。本研究通过分步式添加PbS、Sb_(2)Se_(3)组元以调控n型PbTe基体的热、电传输性能。研究发现,PbS与Sb_(2)Se_(3)组元可分别提升功率因子和降低热导率。通过扩大带隙、增加点缺陷、第二相弥散等途径可改善能带,加剧散射,从而有效提升热电优值ZT。其中(PbTe)0.94(PbS)0.05(Sb_(2)Se_(3))0.01表现出最佳的热电性能,700 K时ZT最大值为1.7,且ZT平均值较PbTe基体显著提高,这表明分步式双组元调控可为改善其它材料体系的热电性能提供技术途径。PbTe recently attracted extensive attentions as potential candidates for applications at intermediate temperatures.However,it is difficult to significantly improve the thermoelectric performance of n-type PbTe due to its relatively low carrier concentration and complicated band structures.In this study,the stepwise addition of dual components was utilized to verify the possibility for modulating the thermal and electrical transport characteristics of n-type PbTe-based materials.The results indicated that PbS and Sb_(2)Se_(3) can improve the power factor and reduce thermal conductivity of PbTe,respectively.Optimization of band structures and enhancement of phonon scattering were realized by means of expanding band gap,producing point defects and secondary dispersoids.As a result,the merit of figure ZT was remarkably improved.In particular,(PbTe)0.94(PbS)0.05(Sb_(2)Se_(3))0.01 exhibited the highest value of ZT=1.7 at 700 K simultaneously with almost doubled average ZT compared to the pristine PbTe.Accordingly,it seems that the stepwise addition of adequate dual components provides possible technological approach for improving thermoelectric performance of other materials.

关 键 词：热电材料 n型PbTe 双重组元 分步式调控 

分 类 号：O472[理学—半导体物理]