Contact angle hysteresis, wettability and optical studies of sputtered zinc oxide nanostructured thin films

Abstract

Zinc oxide (ZnO) nanostructured thin films are deposited by RF magnetron sputtering on corning glass substrates. The effects of RF power and deposition temperature on ZnO nanostructured thin films are investigated. The structural characterization is done by X-ray diffraction; the deposited ZnO nanostructured thin film is amorphous at 30W RF power. The increase of RF power to 90 W and 150 W leads to evolution of (100), (002) and (101) textures of ZnO nanostructured thin films. A well intense (002) peak of ZnO nanostructured thin films is evolved and (100) peak diminishes with increase in deposition temperature from 200ºC to 600ºC. The wettability studies of ethylene glycol are rarely done, so we have investigated contact angle hysteresis and wettability properties of two liquids; water and ethylene glycol on deposited ZnO nanostructured thin films measured by contact angle goniometer. The motivation of this research work is to explore the wettability studies specifically for ethylene glycol on zinc oxide nanostructured thin films as it is used as antifreeze agent and coolant in industry and commercial applications. The contact angle formed by water and ethylene glycol varies as a function of RF power and deposition temperature. The optical properties were measured by UV-Vis-NIR spectrophotometer.