Production of Three-Dimensional ZnO Multilayered Structures from Self-Assembled ZnO Microdiscs

Three-dimensional (3D) zinc oxide (ZnO) multilayered structures with diameters as large as 26.7 µm are obtained in this work in thin-film form. The 1-µm-thick films are produced using the spray pyrolysis method on glass substrates at a substrate temperature of 350 ± 5°C. X-ray diffraction, scanning electron microscopy (SEM), and x-ray energy-dispersive spectroscopy are used to characterize the films. X-ray diffraction revealed that the ZnO films display hexagonal phase with high crystallinity. Scanning electron microscope (SEM) observations showed that the three-dimensional structures are formed from self-assembled ZnO microdiscs. Assembling of the microdiscs and formation of the multilayered structures occurred spontaneously during the deposition process without the aid of any surfactant. This route for the production of ZnO three-dimensional structures is cheap, very simple, and can be used in industrial applications such as gas sensors, electronic devices, and solar cells.