Modification of morphological and optical properties of ZnO thin film

Zink oxide thin films were prepared using different wet-processing techniques to study the morphological and optoelectronic properties. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) have been utilized to study the effect of technique and preparation procedure on the morphology of the films. The spin coated ZnO layers have exhibited ripple-shaped morphological features. Using the growth process with ZnCl2 and Al(NO3)3 doping at different time has shown a change in surface morphology. UV-Visible absorption spectroscopy was used to understand the absorption behaviour and so to calculate the energy gap (Eg) for the films produced. It has been revealed that Eg of the ZnO thin film increases with the increasing of the number of layers spun onto the substrate. ZnCl2 doping has no quite big change in Eg values, however, Al(NO3)3 has resulted in a higher Eg value.