Publication

Abstract : Present work is an attempt to identify the surface and optical characteristics of ZnO thin film prepared by Successive ionic layer adsorption and reaction (SILAR) method. Here the sample was prepared by 20 SILAR cycles from 0.075M Zinc chloride cationic solution and anionic solution of water maintained at 80°C. Obtained sample was annealed at 450°C for 1 hour. Thus prepared ZnO thin film was investigated with Atomic Force Microscope (AFM) and UV-Visible spectrometer. AFM study revealed the grain growth direction and hence the surface roughness of the film. Root mean square roughness (Rq) and average roughness (Ra) were measured as 121.45 nm and 96.206 nm respectively within an area of 6 µm×6 µm. Importance of other parameters obtained like Ten point average roughness (Rz), roughness skewness of the line (Rsk), roughness kurtosis (Rku) of the line were also discussed. With UV-visible spectrometry optical parameters like transmittance (T), absorbance(A) was determined. Peak value of ‘T’ was observed to be 36.174% and it was observed that the sample exhibited high absorption below the wavelength range of 400nm. From the plot of (αhν)2 Vs hν the optical band gap energy Eg was determined and found to be comparable with the literature value. The photon energy lost in the sample was verified by the variation of Extinction coefficient (k) with wavelength. From the calculated value of the reflectance, the refractive index of the sample was also identified. From these investigations the sample was identified with a wavy, rough surface having high absorbance and refractive index values. Hence it is suggested to be a potential candidate for engineering applications.