A facile route to heterostructured ZnO:S/ZnO nanorotors:: Structural and optical properties

We have synthesized heterostructured ZnO:S/ZnO 6-fold nanorotors through a one-step catalyst-free process during chemical vapor deposition. We performed a series of designed experiments to investigate the effect of growth temperatures, growth time, and the ratios between ZnO and FeS used as starting material on the growth. Optimum conditions where maximum nanorotors were obtained were the following: growth temperatures between the range of 400 and 425 degrees C; growth time 100 min; and a 1: 1 ratio of ZnO + FeS. Each heterostructured nanorotor consisted of a core nanowire with side branches emanating from it. Our studies suggest that the core nanowires were ZnO:S while the nanorods were only ZnO. Furthermore ultraviolet-visible spectroscopy was employed to estimate the excitonic absorption peak of the synthesized nanorotors. The photoluminescence spectrum of the hetrostructured nanorotors showed stronger visible band emission as compared to pure ZnO powder at room temperature. This stronger visible emission in the synthesized nanorotors might be useful as a future UV-excited phosphor for producing bright and broadband visible light.