Studies of Cu-doped ZnS thin films prepared by sputtering technique

Radio frequency magnetron sputtering technique has been used to deposit Cu-doped ZnS thin films on glass and n-type Si(100) substrates at room temperature. Crystalline structure, surface morphology, and elemental oxidation states have been studied by X-ray diffraction, field emission scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. Ultraviolet-visible spectroscopy has been employed to measure the transmittance, reflectance, and absorbance properties of coated films. The deposited thin films crystallize in zinc blende or sphalerite phases as proved by X-ray diffraction analysis. The intensity of diffraction peaks decreases with increasing the dopant concentrations. The predominant diffraction peak related to (111) plane of ZnS is observed at 28.52 degrees along with other peaks. The peak positions are shifted to higher angles with an increase of Cu concentrations. X-ray photoelectron spectroscopy studies show that Cu is present in +1 oxidation state. Transmittance, reflectance, and absorbance properties of the deposited films have a slight variation with dopant concentrations. Copyright (c) 2016 John Wiley & Sons, Ltd.