三元PbBi_(2)S_(4)凝固生长与热电性能研究  

Research on the Solid-State Growth and Thermoelectric Properties of Ternary PbBi_(2)S_(4)Compound

作　　者：刘伟 陈彪[2] 肖钰 LIU Wei;CHEN Biao;XIAO Yu(School of Materials and Energy,University of Electronic Science and Technology of China,Chengdu 611731,China;State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China;State Key Laboratory for Mechanical Behavior of Materials,Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]电子科技大学材料与能源学院,四川成都611731 [2]西北工业大学凝固技术国家重点实验室,陕西西安710072 [3]西安交通大学金属材料强度国家重点实验室,陕西西安710049

出　　处：《铸造技术》2024年第4期328-334,共7页Foundry Technology

基　　金：国家自然科学基金(52172236);凝固技术国家重点实验室基金(SKLSP202314);电子科技大学“百人”项目。

摘　　要：三元PbBi_(2)S_(4)是一种具有本征低晶格热导率的潜力热电材料,但低的电传输性能制约了其热电性能。本工作利用Bridgman法制备了高质量的三元PbBi_(2)S_(4)晶体铸锭,由于减少晶界密度,降低晶界对载流子传输阻碍,电传输性能大幅度提升。通过优化生长条件获得不同质量的三元PbBi_(2)S_(4)晶体铸锭,最优加权载流子迁移率从多晶中15 cm^(2)/(V·s)提升到56 cm^(2)/(V·s),使三元PbBi_(2)S_(4)晶体铸锭的最大电导率和功率因子分别达到1049 S/cm和4.6μW/(cm·K^(2)),相比多晶PbBi_(2)S_(4)样品分别提高了850%和~64%。最终,PbBi_(2)S_(4)晶体铸锭的最大ZT值在773 K温度下达到0.61。结果表明,通过凝固生长高质量晶体铸锭能显著优化三元PbBi_(2)S_(4)化合物全温区热电性能。Ternary PbBi_(2)S_(4)is a potential thermoelectric material with intrinsically low lattice thermal conductivity,but the low electrical transport properties limit its thermoelectric properties.In this work,high-quality ternary PbBi_(2)S_(4)crystal ingots were prepared by the Bridgman method.By reducing the grain boundary density to reduce the carrier transport barrier,the electrical transport properties greatly improved.By optimizing the growth conditions,ternary PbBi_(2)S_(4)crystal ingots of different qualities were obtained.The optimal weighted mobility increases from 15 cm^(2)/(V·s)in the polycrystal to 56 cm^(2)/(V·s),and the maximum electrical conductivity and power factor of the ternary PbBi_(2)S_(4)crystal ingot reach 1049 S/cm and 4.6μW/(cm·K^(2)),respectively.Compared with those of the polycrystalline PbBi_(2)S_(4)sample,the increases are 850%and~64%,respectively.Finally,the maximum ZT value in the PbBi_(2)S_(4)crystal ingot reaches 0.61 at 773 K.The results show that the solidification growth of high-quality crystal ingots can significantly optimize the full-temperature thermoelectric properties of the ternary PbBi_(2)S_(4)compound.

关 键 词：PbBi_(2)S_(4)晶体铸锭 晶界 迁移率 功率因子 ZT值 

分 类 号：TB34[一般工业技术—材料科学与工程]