稀土元素Tm掺杂对Cu_(2)S热电性能影响研究  

The influence of rare earth element Tm doping onthe thermoelectric properties of Cu_(2)S

作　　者：刘静[1] 李云凯 王丽阁[1] LIU Jing;LI Yunkai;WANG Lige(School ofMaterials and Chemistry,Southwest University of Science and Technology,Mianyang 621000,China)

机构地区：[1]西南科技大学材料与化学学院,四川绵阳621000

出　　处：《功能材料》2024年第3期3113-3121,共9页Journal of Functional Materials

基　　金：四川省青年科学基金项目(2022NSFSC1999);西南科技大学自然科学基金项目(20zx7106)。

摘　　要：Cu_(2)S具有较低的晶格热导率和窄禁带宽度,它热电性能优异、成本低廉且无毒等优点引起了热电材料相关研究领域的广泛关注。采用水热合成法与真空烧结法相结合的方式制备Cu_(2)S基热电材料,通过物相、成分表征和热电性能测试等手段,研究稀土元素Tm掺杂对Cu_(2)S基材料热电性能的影响规律,并采用第一性原理开展掺杂后Cu_(2)S能带结构和态密度计算。研究结果表明,水热合成法可以获得Cu_(31)S_(16)粉体,在真空烧结过程中物相发生了转变,从原来的Cu_(31)S_(16)转变为Cu_(2)S。掺杂Tm元素可显著提高Cu_(2)S粉体的结晶性能,随着掺杂含量的增加,Cu_(2)S团聚现象逐渐消失。Cu_(2)S塞贝克系数随Tm掺杂量的增加有所提升,其中掺杂2%Tm的Cu_(2)S在350℃处于相变温度,塞贝克系数达到峰值1589.71μV/K;随掺杂元素的增加和温度的升高,Cu_(2)S电导率逐渐下降。Tm掺杂后的Cu_(2)S在中高温度范围内,热导率κ随着温度的上升呈现逐渐下降的趋势。结果表明掺杂2%Tm的Cu_(2)S热电优值从0.1增加到0.4,提高了300%。Cu_(2)S has low lattice thermal conductivity and narrow band gap width,and its excellent thermoelectric performance,low cost,and non-toxic properties have attracted widespread attention in the research field of thermoelectric materials.The present work adopts a combination of hydrothermal synthesis and vacuum sintering to prepare Cu_(2)S based thermoelectric materials.Through phase and composition characterization,as well as thermoelectric performance testing,the influence of rare earth element Tm doping on the thermoelectric properties of Cu_(2)S based materials has been studied.First-principles calculations are used to develop the band structure and density of states of Cu_(2)S.The results indicate that the hydrothermal synthesis method can obtain Cu_(31)S_(16)powders,and the phase transformation occurs during the vacuum sintering process,from the original Cu_(31)S_(16)to Cu_(2)S.Tm element doping can significantly improve the crystallization performance of Cu_(2)S powders,and with the increase of doping content,the agglomeration phenomenon of Cu_(2)S gradually disappears.The Seebeck coefficient of Cu_(2)S increases with the increase of Tm doping amount,with Cu_(2)S doped with 2%Tm at a phase transition temperature of 350℃and the Seebeck coefficient reaching a peak of 1589.71μV/K.With the increase of doping elements and temperature,the electrical conductivity of Cu_(2)S gradually decreases.The thermal conductivity of Cu_(2)S doped with Tm in the medium to high temperature range has a gradual downward trend.The results showed that the figure of merit of Cu_(2)S doped with 2%Tm increases from 0.1 to 0.4,exhibiting an increase of 300%.

关 键 词：热电材料 Cu_(2)S TM 掺杂 

分 类 号：O472[理学—半导体物理]