掺Ag的β-Cu_(2)Se薄膜的溅射沉积及热电性能  

Thermoelectric Properties of the β-Cu_(2) Se Films with Ag Doping by Magnetron Sputtering

作　　者：李贵鹏 宋贵宏[1] 王楠[1] 李秀宇 胡方[1] LI Gui-peng;SONG Gui-hong;WANG Nan;LI Xiu-yu;HU Fang(School of Materials Science and Engineering,Shenyang University of Technology,Shenyang 110870,China)

机构地区：[1]沈阳工业大学材料科学与工程学院,沈阳110870

出　　处：《表面技术》2021年第8期218-226,共9页Surface Technology

基　　金：国家自然科学基金(51772193)。

摘　　要：目的研究Ag掺杂对Cu_(2)Se薄膜物相组成以及热电性能的影响。方法使用粉末烧结的Cu_(2)Se合金靶和高真空磁控溅射设备制备掺Ag的Cu_(2)Se热电薄膜。使用X射线衍射仪(XRD)、扫描电子显微镜(SEM)以及能谱仪(EDS)研究沉积薄膜的物相组成、表面和截面形貌、元素的含量和分布。通过Seebeck系数/电阻分析系统LSR-3测量薄膜的电阻率及Seebeck系数,从而研究不同掺Ag量的Cu_(2)Se薄膜的热电性能。结果使用磁控溅射技术,利用α-Cu_(2)Se合金靶,可制备出以β-Cu_(2)Se相为主,含极少量α-Cu_(2)Se相的Cu-Se薄膜。薄膜中掺杂的Ag不进入β-Cu_(2)Se相的点阵中,而是在薄膜中形成纳米尺寸的CuAgSe第二相。沉积薄膜的β-Cu_(2)Se相点阵中富含Cu,在Ag含量由0增加到2.97%(原子数分数)的变化过程中,其β-Cu_(2)Se相点阵中[Cu]/[Se]比率大于理想比率2.0,由3.59变化到4.96。β-Cu_(2)Se相点阵中富含Cu,使得沉积的β-Cu_(2)Se薄膜的电阻率低于文献中块体材料。随Ag含量的增加,β-Cu_(2)Se薄膜的电阻率先降低、后升高;对于Seebeck系数,电阻率大的薄膜,其Seebeck系数也大。Ag原子数分数为1.37%的样品,因掺杂后Seebeck系数显著提高,其功率因子最大。结论使用磁控溅射技术制备的富Cu的β-Cu_(2)Se薄膜,具有低电阻率的优点。掺杂适量的Ag,能够显著提高薄膜的Seebeck系数,从而获得较高的功率因子。The work aims to study the influence of Ag doping on the phase composition and thermoelectric properties of Cu_(2)Se thin films.Ag-doped Cu_(2)Se thermoelectric thin films were deposited by high vacuum magnetron sputtering using a powder sintered Cu_(2)Se alloy target.The influence of Ag doping on the phase composition and thermoelectric properties of the Cu_(2)Se thin films were studied in this paper.The phase composition,surface morphologies,fracture cross-sections,micro-area element contents and element distribution of the thin films were analyzed by X-ray diffraction(XRD),scanning electron microscopy(SEM)and energy dispersive spectrometer(EDS).The thermoelectric properties of the Cu_(2)Se films with different Ag contents were studied by measuring the resistivity and Seebeck coefficient by Seebeck coefficient/resistance analysis system LSR-3.The results show that the use of magnetron sputtering technology andα-Cu_(2)Se alloy target can prepare Cu-Se thin films withβ-Cu_(2)Se phase as the main phase and a very small amount ofα-Cu_(2)Se phase.The Ag atom doped in the films does not enter the lattice of theβ-Cu_(2)Se phase,but forms a nano-sized CuAgSe second phase in the films.Theβ-Cu_(2)Se phase lattice of the deposited films is rich in Cu.When the Ag content increases from 0 to 2.97at%,the ratio of[Cu]/[Se]in theβ-Cu_(2)Se phase lattice is more than the ideal ratio of 2.0,enhancing from 3.59 to 4.96.The resistivity of the depositedβ-Cu_(2)Se films is significantly lower than that of bulk materials in the literature due to Cu-rich inβ-Cu_(2)Se phase lattice.With the increase of Ag content,the resistivity of the depositedβ-Cu_(2)Se films decreases first and then increases;the Seebeck coefficient of the films increases with resistivity.The sample with Ag content of 1.37at%has the highest power factor due to the significantly higher Seebeck coefficient.The Cu-richβ-Cu_(2)Se films prepared by magnetron sputtering has low resistivity,and the appropriate amount of Ag-doping can significantly increase the ab

关 键 词：热电材料 磁控溅射 β-Cu_(2)Se薄膜 AG掺杂 SEEBECK系数 电阻率 

分 类 号：TG174[金属学及工艺—金属表面处理]