Transition width effect on optical characterizations of ZnO thin films deposited by spray ultrasonic

Abstract

Ultrasonic spray deposition was successfully employed to the synthesis of ZnO thin films, then found that can be suitable for application as a transparent conducting electrode. The effects of substrate temperature with film deposition on structural, optical and electrical properties of very thin ZnO films were investigated. ZnO thin films were observed in high crystallinity with a hexagonal wurtzite structure with a strong preferential c-axis, the maximum value of crystallite size 44.53 nm is attained of deposit ZnO thin film at 420 °C. The optical transmission spectra showed all the sprayed ZnO thin films are transparency within the visible wavelength region. Found that the highest transition region (width) ΔE have a higher optical gap energy and smaller urbach energy, which it is 3.26 eV and 0.053 eV respectively. The electrical conductivity was varied in the range of 1 to 5 (Ω.cm)−1 as a function of deposition temperature.