Chemical solution deposition of ZnO nanostructure films: Morphology and substrate angle dependency

A chemical solution deposition method was used to synthesize ZnO films on zinc foil utilizing an electrolyte of ZnCl2 + H2O2 under ambient conditions. The structures, morphologies, and chemical compositions of the films were characterized using X-ray diffractometry (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), and X-ray photoelectron spectroscopy (XPS) techniques. The XRD patterns showed that the substrate angle had significant influences on the formation of Zn(OH)2 and the transition to ZnO. The SEM observations revealed that the cauliflower-like and rod-like morphologies were altered to one that was disk-like by changing the substrate angle from 90° to 0°. The XPS and EDS results indicated the presence of Cl atoms with a substrate angle of 0°. The XPS data confirmed the chemical purity of the ZnO film on the substrate with 90°. Photoluminescence (PL) studies found different visible emissions originating from different defect mechanisms. The growth mechanism responsible for the variation in the morphology is discussed. The observed results showed that the variation of pH in the vicinity of the surface substrates can be considered as reason for changing of morphology with the variation of angle. This method may have a potential in the fabrication of other metal oxides at low cost for technological applications.