ZnO Inverse Opals Using Colloidal-Crystal Template Assisted Hydrothermal Method

Both two-dimensional (2D) ZnO nanobowl arrays and three-dimensional (3D) ZnO inverse opals were fabricated using hydrothermal method with assistance of the three-dimensional colloidal crystal templates. Scanning electron microscope measurements showed the morphological evolutions of ZnO from rods to 2D monolayer nanobowl arrays and 3D porous films by controlling the concentration of hydrothermal solutions and reaction time. The photonic stop b and was characterized using reflections spectra presenting the 3D periodic geometry. The photoluminescence spectra indicate good crystalline quality via the hydrothermal route.