Synthesis of ZnO NWs via Thermal Evaporation Technique

Abstract

Zinc oxide nanowires ZnONWs were successfully synthesized on glass slides. The synthesis was conducted firstly by the deposition of 12 µm a thin film of Zn metal by thermal evaporation. Secondly,the coated film was annealed at a temperature of 600 ºC in air for four hours to grow the ZnO nanowires. It have been observed that the produced nanowires were grown in a vertical orientation and having a high density, very long, and a minimal aspect ratio. The crystal structure and morphology of ZnO nanowires were investigated with X-ray diffraction (XRD) and scanning electron microscopy (SEM). The UV-visible spectrophotometer was also used to calculate the optical parameters from the absorption spectrum and show a band gap energy around 3.25 eV. The crystal structure of the material was revealed to be polycrystalline with a preferred orientation in the direction of [101]. Small average crystallite size was calculated about 17nm The wires can be measured to have a length of around 10 µm with diameters ranging from 50 to 100 nm. This could be used for gas sensor applications. In addition, this ZnONWs structure has a maximum transmittance (100%) which can be a good candidate for many optoelectronic apllications.