Fabrication of 2D and 3D ordered porous ZnO films using 3D opal templates by electrodeposition

Both two- and three-dimensional ordered porous zinc oxide films were fabricated by electrodeposition using three-dimensional polystyrene opal templates. Scanning electron microscope measurements showed that the dimensions (monolayer or multilayer) of porous zinc oxide films can be controlled by selecting zinc nitrate in different solvents (water or mixed ethanol-water solvents). Optical measurements showed that the porous structures generated in mixed ethanol-water solutions exhibited the photonic stopband, indicating large-scale crystalline order in the samples. It was found that the position of stopband center and the surface morphologies in the three-dimensional zinc oxide porous films were dependent on the ethanol content in the electrolyte. The influence of ethanol content on the porous films was discussed.