Ni掺杂对β-Cu_(2)Se薄膜微观结构和热电性能的影响  

Microstructure and Thermoelectric Properties ofβ-Cu_(2)Se Films Doping with Ni

作　　者：王楠[1] 宋贵宏[1] 陈雨 李贵鹏 胡方[1] 吴玉胜[1] 杜昊 Wang Nan;Song Guihong;Chen Yu;Li Guipeng;Hu Fang;Wu Yusheng;Du Hao(School of Materials Science and Technology,Shenyang University of Technology,Shenyang 110870,China;Institute of Corrosion Science and Technology,Guangzhou 510530,China)

机构地区：[1]沈阳工业大学材料科学与工程学院,辽宁沈阳110870 [2]广东腐蚀科学与技术创新研究院,广东广州510530

出　　处：《稀有金属》2024年第3期365-377,共13页Chinese Journal of Rare Metals

基　　金：国家自然科学基金面上项目(51772193);辽宁省“兴辽英才计划”项目(XLYC2008014)资助。

摘　　要：采用磁控溅射的方法和粉末真空烧结的Cu-Se合金靶材,使用高真空磁控溅射技术在单晶Si(100)衬底上制备掺杂Ni的β-Cu_(2)Se热电薄膜。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、电子探针和能谱仪(EDS)分别研究薄膜的相组成、表面和截面形貌、微区元素含量与分布。利用塞贝克(Seebeck)系数/电阻分析系统LSR-3测量沉积薄膜的Seebeck系数和电阻率,研究Ni含量对β-Cu_(2)Se薄膜热电性能的影响。结果表明,使用烧结的Cu-Se合金靶材和利用磁控溅射技术可制备出仅有单一β-Cu_(2)Se相的薄膜,Ni掺杂没有改变β-Cu_(2)Se相结构,而是在薄膜中形成替位式固溶体,沉积薄膜具有高度(111)晶面择优取向。在沉积的β-Cu_(2)Se薄膜中,当Cu与Ni原子含量之和与Se原子含量比(([Cu]+[Ni])/[Se])大于2.0,具有p型导电特征。随Ni含量的增加,沉积β-Cu_(2)Se薄膜的载流子浓度增加,而载流子迁移率下降。在所研究的温度范围内,掺杂Ni薄膜的电阻率和Seebeck系数均随着Ni掺杂量的增加而减小,并且都低于未掺杂薄膜。Ni掺杂量为1.80%(原子分数)的薄膜,因其电阻率和Seebeck系数适当,功率因子最大,高于未掺杂薄膜。掺杂适量Ni可有助于提高β-Cu_(2)Se薄膜的功率因子。Cu_(2)Se,which possesses the structure of phonon glass-electron crystal(PGEC),is an excellent thermoelectric material,which is not only due to the excellent thermal(ultra-low thermal conductivity)and electrical(low resistivity)transport properties,but also due to its unique properties such as environmental friendliness,low cost,low toxicity,rich in rare earth elements,high power factor(PF)and high figure of merit(zT)values.In this work,Ni-dopedβ-Cu_(2)Se thermoelectric films were prepared on high pure intrinsic single Si(100)substrate with a thickness of 0.5 mm using vacuum powder-sintered Cu-Se alloy target by the high vacuum magnetron sputtering.The crystalline structure,phase composition,element content and distribution,existence form and valence state of Cu,Se and Ni element,surface and cross-sectional morphology of the deposited films were studied and observed.The room temperature carrier concentration(n)and carrier mobility(μ)were calculated by Hall experiments and the resistivity and Seebeck coefficient of the deposited Cu-Se thin films were measured.Results showed that the deposited Cu-Se thin films were composed of only a singleβ-Cu_(2)Se phase,andβ-Cu_(2)Se films possessed a highly(111)referred orientation and the level of the(111)referred orientation of the films increased with increasing Ni content.The doping Ni substituted Cu inβ-Cu_(2)Se lattice in deposited thin films and aβ-(Cu,Ni)_2Se solid solution formed instead of forming metal Ni phase or Ni compound.The X-ray photoelectron spectroscopy(XPS)of Cu 2p and Se 3d proved Cu^(+)and Se^(2-)valence in deposited Ni-dopedβ-Cu_(2)Se films.The binding energy of 853.35 and 870.61 eV of Ni 2p_(3/2)and Ni 2p_(1/2)proved NiSe bond or NiSe_(2) bond valence,namely Ni^(^(2+))valence.This also indicated that Ni occupied the position of Cu atoms inβ-Cu_(2)Se lattice andβ-(Cu,Ni)_(2)Se solid solution existed with no secondary phase.All deposited films showed a columnar grain growth along the direction perpendicular to substrate due to a large number of nu

关 键 词：热电材料 β-Cu_(2)Se薄膜 Ni掺杂 择优取向 SEEBECK系数 

分 类 号：TQ125.2[化学工程—无机化工]