Tunable luminescence of pure ZnO nanowires prepared by microwave irradiation in ethanol

In this work, ZnO nanowires were synthesized using zinc acetate, ethanol, and poly (N-vinylpyrrolidone, 40000) (PVP) by microwave irradiation with controllable luminescence properties. This method is very fast, simple and without any doping agent the luminescence of ZnO nanowires is tunable. Effect of variation of PVP/Zn mole ratio on the luminescence properties of the samples has been studied. Structural analysis was performed by means of X-ray diffraction and scanning electron microscopy. The results revealed that microstructure and morphology of the samples does not change significantly with the change of PVP. UV–Vis absorption spectroscopy indicates that with the increase of PVP, the absorption tail increases. Photoluminescence spectroscopy indicated that nanowires emit different colors from blue to yellow just by the increase of PVP. The considerable emission of the deep-level luminescence can be ascribed to the increase in the density of oxygen and zinc interstitials at the surface of ZnO due to successful incorporation of PVP in surface modification of nanowires.