Modeling of grain size growth in pure ZnO thin films prepared by the sol gel method

Abstract

In this work, the theoretical and experimental results on the effect of annealing temperature on the structural properties of sol-gel zinc oxide (ZnO) thin films are presented. The theoretical approach has been developed to study the distribution of grain sizes during the crystallization step. The population balance equations (PBE) coupled with the Monte Carlo method (MC) have been used in case of zinc oxide (ZnO)200 nm thick film deposited on glass substrates. The results show that the distribution of grain sizes in the film follows a Gaussian log-normal distribution at different temperature. The highest crystallinty was obtained at annealing temperature of 500°C with grain size of about 19 nm.The theoretical results were validated by experimental results, were ZnO thin films deposited by sol gel method using spin coating were annealed at different temperatures ranging from 350 °C to 500 °C during 1h. Structural properties were studied using x-ray diffraction (XRD) analysis. The experimental results showed that the grain growth with the preferential orientation is obtained according to the (002) plane with an average grain size equal to about 27 nm at a temperature of 500 °C and annealing time of 60 min.