Effects of annealing on the structure and photoluminescence of ZnO-sputtered coaxial nanowires

We reported the preparation and annealing effects of Zinc oxide ZnO/SiOx core–shell nanowires, in which ZnO shell layers were deposited by sputtering. Based on scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and photoluminescence (PL) investigations, we monitored structural and optical changes with respect to the post-annealing process. The samples were mostly amorphous with some crystalline ZnO structure, whereas annealing at 900–1000 °C reduced the amount of Zn elements. Thermal annealing induced change in the shape of the PL emission spectra.