Impact of Deposition Rate on the Structural, Optical, and Electrical Properties of Zinc Oxide (ZnO) Thin Films Prepared by Solar Spray Pyrolysis Method.

In the present research, thin films of zinc oxide (ZnO) are elaborated by solar spay pyrolysis method with using solar energy to heat glass substrate at 450°C in ambient atmosphere without any special conditions. This method was developed in our laboratory using simple tools. The zinc acetate with a molarity of 0.1 M was sprayed with deferent deposition rates (7, 11 and 13 ml). The effect of such depositions on the structural, optical, and electrical properties is examined by using x-ray diffraction (XRD), ultraviolet and visible spectroscopy, and four-point probe method, respectively. The analysis of properties shows that ZnO films are polycrystalline with the preferential orientation (002) and are crystallized in the wurtzite-phase type. The grain size increases to 23 nm, then decreases until it reaches 16 nm. The direct band-gap value decreases from 3.30 to 3.28 eV, when the thickness increases from 126 to 148 nm. As revealed, the conductivity varies with film thickness. [ABSTRACT FROM AUTHOR]