Zinc Oxide Nano-Cauliflower Array with Room Temperature Ultraviolet Light Emission

A novel geometry of a ZnO nanocauliflower array has been fabricated by an electrochemical route of the electrophoresis deposition of anionic polystyrene spheres on a conductive glass substrate followed by the electrodeposition of ZnO in aqueous solutions. The structural and optical characteristics were investigated by using X-ray diffraction, field-emission scanning electron microscopy, and photoluminescence spectrum measurements. The ZnO nanocauliflower was constructed of a polystyrene sphere core and a shell of ZnO hexagonal columns radially grown from the sphere surface. The ZnO nanocauliflower array possessed a high quality that emits ultraviolet light at a photon energy of 3.3 eV at room temperature due to the recombination of bound excitons.