Cu掺杂优化层状PbBi_(4)Te_(7)化合物的热电性能  

Optimizing thermoelectric performance of layered PbBi_(4)Te_(7)compound through Cu doping

作　　者：曾宏 刘伟[1,2] 徐莉青 邓朝广 肖钰 Hong Zeng;Wei Liu;Liqing Xu;Chaoguang Deng;Yu Xiao(State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,Xi’an 710049,China;School of Materials and Energy,University of Electronic Science and Technology of China,Chengdu 611731,China;Chengdu Polytechnic,Sichuan Provincial Engineering Research Center of Thermoelectric Materials and Devices,Chengdu 610041,China)

机构地区：[1]西安交通大学,金属材料强度国家重点实验室,西安710049 [2]电子科技大学材料与能源学院,成都611731 [3]成都职业技术学院,四川省热电材料与器件应用工程研究中心,成都610041

出　　处：《科学通报》2025年第6期718-728,共11页Chinese Science Bulletin

基　　金：国家自然科学基金(52172236);电子科技大学“校百人”支持计划资助。

摘　　要：三元PbBi_(4)Te_(7)化合物因具有本征低晶格热导率而被认为是一种很有潜力的热电材料,但低的电传输性能限制了其热电性能.为此,本研究采用熔融法制备PbBi_(4)Te_(7)化合物,通过Cu掺杂提升了三元PbBi_(4)Te_(7)化合物的热电性能.结果表明,Cu掺杂可增强层间电子传输通道,使层间室温载流子迁移率从PbBi_(4)Te_(7)样品中100 cm^(2)V^(−1)s^(−1)提升至PbBi_(4)Te_(7)-0.1%Cu样品中160 cm^(2)V^(−1)s^(−1),使PbBi_(4)Te_(7)-0.1%Cu样品的最大功率因子达到11.3μW cm^(−1)K^(−2).同时,Cu掺杂可增强层间声子散射,使得PbBi_(4)Te_(7)-0.1%Cu的最低晶格热导率达到0.20 W m^(−1)K^(−1).最终,在Cu对层间电输运和热输运性能的协同优化下,PbBi_(4)Te_(7)-0.1%Cu的最大ZT(ZT_(max))值提升到0.59,近室温区(300~573 K)的平均ZT(ZT_(ave))值达到0.48.PbBi_(4)Te_(7)-0.1%Cu样品与其他典型的三元Pb-Bi基化合物相比具有较大优势,表明了其作为近室温热电材料的良好潜力.Global energy and environmental challenges are an urgently required on the development of efficient,green and clean energy materials due to the consumption of fossil fuels.Thermoelectric materials,which enable the direct conversion between heat and electricity,hold great promise in applications such as waste heat recovery,energy utilization and refrigeration.In this context,more and more researchers are focusing on exploring ternary high-performance thermoelectric materials.Among the newly discovered ternary chalcogenides(IV-VI)n(V2-VI3)m(IV=Ge,Sn,Pb;VI=Se,Te;V=Sb,Bi),PbBi_(4)Te_(7)has attracted increasing attention due to its low lattice thermal conductivity and unique layered crystal structure.Previous studies have indicated that the intrinsic low lattice thermal conductivity of PbBi_(4)Te_(7)is primarily attributed to strong phonon scattering at the interfaces with its complex layered stacking structure.However,this structure also significantly reduces carrier mobility and limits the enhancement of its thermoelectric properties,which is also an issue commonly encountered in most layered thermoelectric materials.In recent years,Cu doping has been proven to be an effective method for enhancing interlayer carrier transport and achieving high ZT value in layered thermoelectric materials such as Bi_(2)Te_(3),Sb_(2)Te_(3) and SnSe_(2).Understanding the effects of Cu on the thermoelectric properties of layered PbBi_(4)Te_(7)in detail is of great importance.In this study,Cu doping is adopted to synergistically regulate its electrical and thermal transport to improve the thermoelectric properties of PbBi_(4)Te_(7).A series of PbBi_(4)Te_(7)-x%Cu(x=0–1)compounds were prepared by the melting method.These compounds were comprehensively characterized using techniques such as X-ray diffraction(XRD)and Hall coefficient measurement systems,etc.The results show that PbBi_(4)Te_(7)with unique layered structure exhibits anisotropic carrier and phonon transport behavior.Specifically,PbBi_(4)Te_(7)demonstrates an extremely low l

关 键 词：PbBi_(4)Te_(7)热电材料 层间迁移率 功率因子 晶格热导率 ZT值 

分 类 号：TB34[一般工业技术—材料科学与工程]