Relationship between Crystal Structure and Photoluminescence Properties of ZnO Films Formed by Oxidation of Metallic Zn

ZnO nanowires were formed on ZnO films by the oxidation of Zn at a temperature of 600 degrees C in air. The maximum intensities of the (002) and (101) diffraction peaks were observed for the ZnO film with nanowires on its surface. The finding that the intensities of the (002) and (101) peaks simultaneously exhibited maximum values conflicts with the conventional XRD patterns reported in many other studies on ZnO films. The highest intensity of the (002) peak results from the better crystalline quality than films prepared at other oxidation temperatures, and the highest intensity of the (101) peak is attributed to the higher density of nanowires. In addition, the ZnO film with nanowires exhibited the strongest UV emission intensity.