Preparation and optical properties of ZnO nanostructures

Zinc oxide nanostructures were directly grown by a low temperature hydrothermal reaction without surfactant, using zinc foils as both source and substrate in NaOH solution. The effect of pH value in solution and growth time on the morphologies and sizes of the nanostructures were investigated. The growth mechanism of the as-synthesized ZnO nanostructures was discussed. Their photoluminescence properties were characterized. There are a intensive ultraviolet light emission peak and weak visible emission band in the photoluminescence spectra of the ZnO nanorods while for the ZnO thin films a strong visible emission band was observed. Their photoluminescence origin is discussed.