Effect of Zinc Acetate Concentration on Structural, Optical and Electrical Properties of ZnO Thin Films Deposited by Electrostatic Spray on an ITO Substrate

Abstract

Polycrstalline zinc oxide (ZnO) thin films were fabricated on indium tin oxide (ITO) substrates by electrostatic spray deposition using propylene glycol as the solvent for potential use in bulk heterojunction polymer solar cells. The microstructure and characteristics of the ZnO/ITO bilayer have been investigated for various precursor concentrations using SEM, AFM, X-ray diffraction, and UV-Visible spectroscopy. The bandgap energy of the bilayer slightly decreases when the zinc acetate dihydrate concentration in the propylene glycol solvent increases from 0.1 to 0.3 M. The ZnO/ITO bilayer shows high figure of merit (12.4 × 10−3 Ω−1) and low resistivity (3.78 × 10−3 Ω-cm) for a Zn precursor concentration of 0.2 M.