Co掺杂ZnO纳米棒的电沉积法制备及其光学性能

Preparation and Optical Properties of Co-doped ZnO Nanorods by Electrodeposition Method

在Zn(NO3)2和Co(NO3)2溶液中,以柠檬酸作为络合剂,采用阴极恒电位沉积法直接在ITO衬底上制备出纯ZnO和Co掺杂ZnO(ZnO∶Co)纳米棒阵列膜。采用X射线衍射、扫描电镜和能量色散谱对所制备ZnO纳米棒的晶体结构和表面形貌进行了表征,利用光致发光光谱研究了样品的发光性质。结果表明:所制备的ZnO纳米棒呈六角纤锌矿结构,具有沿(002)面择优生长特性,Co掺杂使ZnO纳米棒的直径变细。部分Co2+取代了Zn2+进入ZnO的晶格,掺入量为2.2at%左右。Co掺杂使ZnO的禁带宽度变窄,紫外发射峰产生显著红移。

Pure and Co-doped ZnO（ZnO ： Co） nanorods array films were fabricated on ITO substrate using the potentiostatic electrodeposition method in Zn（NO3）2 and Co（NO3）2 solution by adding citric acid as the complex agent. The crystal structure and morphology of the asprepared samples were characterized by XRD, SEM and EDS. The optical properties of the samples were studied by photoluminescence （PL） spectra. The results show that the assynthesized ZnO： Co nanorods with hexagonal wurtzite structure possess （002） plan preferred orientation property, the nanorods have smaller diameter than pure ZnO because of Co-doping. Part of Co^2＋ replace Zn^2＋ into the ZnO nanocrystals, the dopant content is about 2.2 at%. A remarkable red-shift can be observed in the UV luminescence of the ZnO ： Co nanoerystals, due to the band gap narrowing of ZnO with the Co dopant.