Significance of Annealing Temperature on Transmission Properties of ZnO Thin Film by Hydrothermal Method

In this study Zinc oxide (ZnO) thin films were prepared using a low cost hydrothermal method and investigated for the effect of different annealing temperatures. The ZnO precursor solution was made using zinc acetate dehydrate Zn(CH₃COO)_2.2H₂O (ZAD) and hexamethylenetetramine C₆H₁₂N₄(HMT). The samples were annealed at different temperatures (100°C, 200°C, 300°C, 400°C & 500°C) for 90 minutes and irradiated using refractory furnace. Thin films were analyzed using ultra violet-visible spectrophotometry, X-ray Diffraction (XRD) with Cu-Kα radiation to determine the structure of the film, four probe and two probe method for electrical properties and Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDX) for surface morphology and chemical composition. Result shows the 500°C annealing produce good thin films as well as the increasing deposition time from 4 to 24 hours leads to higher crystalline films with increased transmittance.