Sonochemical Assisted Synthesis of ZnO Nanostructured thin Films Prepared by Sol-gel Method

In this article, the effect of applying sonication on the characteristics of zinc oxide (ZnO) thin films prepared by sol-gel method is investigated. ZnO films were deposited on glass substrates using spin coating technique. Zinc acetate dehydrate, ethanol, and triethylamine were used as the zinc source, solvent, and stabilizer, respectively. The as-deposited films were dried at 300°C for 10 min. The spin-coating and drying steps were repeated for depositing ten layers to reach the desired thickness. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and UV-Vis spectroscopy analyses were used to study the crystallinity, morphology, and optical properties of the films. XRD spectra show that the samples were crystallized in wurtzite structure and sonication treatment has no effect on crystal phase. However, the crystallinity and preferred orientation growth were remarkably changed. The average grain size observed by FESEM for sonicated films is larger than those for films without sonication. UV-Vis spectroscopy shows that optical band gap energy slightly decreases by sonication.