湿化学法硫掺杂提高湿化学法制备硒化银的热电性能  

Solvothermal preparation of silver selenide doped by sulfur and its thermoelectric properties

作　　者：程怡然 高杰[1] 刘呈燕 谢正川 余中海 张忠玮 李佳慧 白小波 司瑞凡 苗蕾[1] CHENG Yiran;GAO Jie;LIU Chengyan;XIE Zhengchuan;YU Zhonghai;ZHANG Zhongwei;LI Jiahui;BAI Xiaobo;SI Ruifan;MIAO Lei(School of Materials Science and Engineering,Guilin University of Electronic Technology,Guilin 541004,China)

机构地区：[1]桂林电子科技大学材料科学与工程学院,广西桂林541004

出　　处：《桂林电子科技大学学报》2022年第4期305-310,共6页Journal of Guilin University of Electronic Technology

基　　金：国家自然科学基金(51801040,51961011,51772056);广西自然科学基金(2018GXNSFAA294135)。

摘　　要：硒化银(Ag_(2)Se)是一种典型的适用于室温附近的热电材料,尽管掺杂异质原子是优化热电性能的有效方法,但低能耗湿化学法制备的硒化银基热电材料往往难以实现精准掺杂。为了实现精准控制掺杂含量以制备高性能的硒化银基热电材料,采用单质硒(Se)和硝酸银(AgNO_(3))为原料,以乙二胺为溶剂,采用湿化学法制备硒化银基体粉末,再通过熔融法将单质硫(S)掺入硒化银,最后通过放电等离子烧结(SPS)制备成高性能块体材料。对不同硫(S)含量掺杂的硒化银基材料采用X射线衍射法(XRD)进行物相分析,使用能谱仪(EDS)进行微区元素分析,并利用热电性能测试系统对其在300~400 K温度范围内的热电性能进行测试。实验结果表明,掺杂样品在低温相下实现了泽贝克系数(α)的显著提升和热导率(κ)的显著下降,掺杂含量为3%摩尔百分比的样品在393 K的泽贝克系数约为-152μV·K^(-1),热导率约为0.91 W·m^(-1)·K^(-1)。最终,掺杂浓度为3%摩尔百分比的样品在393 K下取得0.81的最高zT值。因此,单质硫掺杂是一种调控硒化银基材料热电性能的有效方法。Silver selenide(Ag_(2)Se)is a typical thermoelectric material suitable for application near room temperature.Doping heteroatom is an effective method to optimize the thermoelectric properties.However,the precise doping of Ag_(2)Se prepared by the wet chemical methods is difficult to accomplish.To achieve precise control of doping content,which is important to obtain Ag_(2)Se-based materials with high thermoelectric performance,the Ag_(2)Se powders were synthesized by a hydrothermal method using ethylenediamine as the solvent,silver nitrate(AgNO_(3))and elemental selenium(Se)as the raw materials.Then,the matrix Ag_(2)Se was doped with elemental sulfur(S)by a melting method,and bulk materials with high thermoelectric performance is prepared by a spark plasma sintering(SPS).X-ray diffraction(XRD)and energy dispersive spectrometer(EDS)were used to conduct phase analysis and microscopic element analysis of the sample doped with sulfur in different content,and the thermoelectric performance at 300-400 K was tested by a thermoelectric performance test system.The result shows that the doped sample achieves a significant increase in Seebeck coefficient(α)and a decrease in thermal conductivity(κ)in the low temperature phase.The Seebeck coefficient(α)of the sample with a doping content of 3%mole is about-152μV·K-1 at 393 K,and the thermal conductivity(κ)is 0.91 W·m^(-1)·K^(-1)at 393 K.Finally,the sample doped by 3%molar sulfur reaches a peak zT to 0.81 at 393 K.

关 键 词：硒化银 湿化学法 硫掺杂 热电性能 

分 类 号：O472[理学—半导体物理]