optical properties of zno nanowires and nanorods synthesized by two step oxidation process

zno nanowires with a diameter of 70 nm and nanorods with a diameter in the range of 100-150 nm and two micrometer in length were grown on glass substrates by resistive evaporation method and applying a two step oxidation process at low temperatures, without using any catalyst, template or buffer layer. xrd pattern of these nanostructures indicated a good crystallinity property with wurtzite hexagonal structure. photoluminescence measurement revealed three band emissions; one sharp strong peak in the uv region and two weaker peaks in the visible region, indicate good optical properties of nanorods synthesized by this method. heat treatment in oxygen-rich atmosphere results to decrease of deep-level emission intensity in the pl spectra. the relatively high intensity of uv emission implies that this approach is a simple and promising method for fabricating zno nanorods in order to be used in optoelectronic devices especially in the uv range of the spectrum.