Photocatalytic and electrically conductive transparent Cl-doped ZnO thin films via aerosol-assisted chemical vapour deposition

Abstract

A simple, economical and effective solution-based chemical vapour deposition (CVD) technique, aerosol-assisted CVD, has been successfully applied to produce inexpensive Cl-doped ZnO films using Zn acetate dihydrate and FeCl₃. X-ray photoelectron spectroscopy and the increase in cell parameters from powder X-ray diffraction determined that Cl had been doped into the wurtzite ZnO lattice. The Cl-doping had a significant effect on the morphology of the thin films synthesised and resulted in an improvement in the visible light transmission and lower electrical resistance (typical resistivities of doped films ∼10⁻² Ω cm). The highest transmittance (% T) of 85% was obtained when 7 mol% FeCl₃ was used in the precursor solution and the lowest resistivity of 4.28 ± 0.41 × 10⁻² Ω cm was obtained with 5 mol% FeCl₃. The greatest photocatalytic activity of stearic acid degradation under UVA irradiation was obtained on using 10 mol% FeCl₃, resulting in the highest formal quantum efficiency (FQE) of 3.0 ± 0.1 × 10⁻⁴ molecule per photon. These films, therefore, display transparent conducting oxide and photocatalytic properties, giving multifunctional characteristics and promising applications.