Studies on sol-gel dip-coated nanostructured ZnO thin films

Abstract

Nanostructured ZnO thin films were prepared by sol-gel dip coating technique. Zinc acetate and ammonium hydroxide were used as precursors and ethanol was as solvent. Ammonium hydroxide (NH4OH) solution was added drop-wise under vigorous stirring to obtain the sol-gel of different pH (varying from 6.9 to 7.2). ZnO thin films were obtained by dipping the glass substrates for few seconds and then dried in air at room temperature. This process was repeated for different number of coats for the typical sol. Different numbers of coating cycle was employed to obtain the films with varying thicknesses. These films were annealed at 5000C and were characterized by x-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive analysis of x-rays (EDAX). ZnO thin films obtained from sol-gel dip-coating technique were observed to nanostructured. Average particle size was observed to be smaller than 50 nm. The most of the particles were observed to be spherical in shape. ZnO films were observed to be nonstoichiometric (Zinc deficient) in nature. The results were discussed and interpreted.