超声电化学沉积ZnO薄膜及其机理研究

Research on fabrication of ZnO films by ultrasonic electrochemical deposition and its mechanism

采用超声电化学沉积生长了c轴取向的ZnO薄膜,并与常规电化学沉积生长的ZnO薄膜进行了比较。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见分光光度计研究了样品的晶体结构、表面形貌以及光学性能。结果表明,常规电化学沉积生长的ZnO薄膜为纳米柱状结构,随着沉积电压的增加,c轴取向率呈极值变化,热退火可提高这种薄膜的透射率。超声电化学沉积生长的ZnO薄膜,在1.5V低沉积电压下仍为柱状结构,但比未加超声电化学法沉积的样品具有更好的c轴取向,沉积电压增加到2.0V时样品则变为麦粒状结构,热退火后其透射率几乎不变。

C-axis oriented ZnO films were fabricated by ultrasonic electrochemical deposition （UED）. For comparison,ZnO films were also prepared by conventional electrochemical deposition （CED） in the same condition. X-ray diffraction, scanning electron microscopy and optical spectroscopy were used to analysize the structure, surface morphology and optical properties of the films. The results show that ZnO films deposited by CED have the nano-column shape and c-axis orientation presents maximum when increasing the deposition voltage. Also, the optical transmittance is improved by annealing process. The ZnO films deposited at 1.5V by UED still show the nano-eolumn shape, but exhibit a better c-axis orientation than those prepared by CEM. However,as the deposition voltage increase to 2. 0V, the films show wheat granular structure. The optical transmittance is hardly influenced by post-annealing in this case.