Effect of substrate temperature studies on spray pyrolysis deposited ZnO thin films

In the present work and in the order to obtain conducting transparent layers, ZnO thin films were deposited by pyrolysis spray technique, zinc acetate was used as starting solution with a molarity of 0.1 M. The glass substrate temperature was varied in the range of 250 °C–400 °C to investigate the influence of substrate temperature on the structure and optical properties of ZnO films. Optical film characterization was carried by using UV–visible transmission spectroscopy in the spectral range 300-1100 nm; the optical gap was deduced from absorption. From X ray diffraction (XRD) analysis, we have deduced that ZnO films are formed with nanocrystalline structure with preferential (002) orientation. The grain size is increased with the substrate temperature (300 to 350 ° C) from 12.5 to 15.5 nm, and then it is decreased to 14 nm (400 ° C). However the optical gap is varied from 3.12 to 3.32 eV.