Growth of Zinc Oxide Nanorod and Nanoflower Structures by Facile Treatment of Zinc Thin Films in Boiling De-Ionized Water

In this work, zinc oxide nanostructured films were developed by a facile treatment of the sputter deposited zinc thin films in boiling de-ionized water. Arrays of zinc oxide nanostructures with rod and flower-like shapes were obtained by changing the boiling water treatment time and manipulating the thickness of zinc film. Results of the scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction, ultraviolet-visible-near infrared spectroscopy, and photoluminescence techniques indicate that the obtained nanostructures are crystallized stoichiometric zinc oxide. Zinc oxide nanorods and nanoflowers start to form on the surface and progress across the zinc film’s thickness as a function of treatment time in boiling de-ionized water, which allow a controllable method of fabricating semiconducting/metal multilayer coatings. The obtained nanostructured films showed different optical properties depending on starting zinc film’s thickness and boiling water treatment time. In addition, photoluminescence analysis showed that the nanostructured films possess a major energy band gap of 3.28 eV along with two other secondary defects-related energy band gaps of 2.27 and 1.67 eV.