pH值对电沉积法制备ZnS光学薄膜影响的研究

Influence of pH Value on the ZnS Optical Thin Films Prepared by Electrodeposition

采用阴极恒电压法在ITO导电玻璃上沉积了ZnS薄膜,并用X射线衍射仪(XRD)、原子力显微镜(AFM)以及紫外/可见/近红外光谱仪对薄膜的结构和性能进行了表征,研究了pH值对薄膜的相组成、显微形貌以及光学性质的影响。结果表明:在pH=4,沉积时间为20 min,沉积电压为2 V,加入柠檬酸钠作络合剂的情况下,得到沿(200)晶面生长的立方相ZnS薄膜,薄膜组成均匀而致密,随pH值增加,禁带宽度降低。

ZnS thin films were prepared on ITO substrates using a constant voltage cathodic electrodeposition process. The as-deposited thin films were characterized by X-ray diffraction （XRD） , atomic force microscopy （ AFM ） , and UV-Vis-NIR spectrometer. The influences of pH value on the phase compositions, surface morphologies and optical properties of the films were investigated. Results show that cubic ZnS thin films with oriented growth along （200） direction can be obtained at pH = 4,t = 20 min, U = 2 V and adding Na-citrate as complexing agent. The as-deposited thin films exhibit a dense surface morphology. The optical bandgape of the ZnS thin films decreases with the increases of pH value.