The effect of bath temperature on the electrodeposition of zinc oxide thin films via an acetate medium

Abstract

The temperature-dependent nucleation and growth mechanism of electrodeposited zinc oxide (ZnO) thin films on fluorine-doped tin-oxide-coated (10-20 Ωcm^-2) glass substrates from an acetate solution was studied by using the chronoamperometry technique. The morphological, compositional and structural properties were studied by scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS) and x-ray diffraction techniques. The current transients were analyzed by fitting chronoamperometric data into the Scharifker-Hills nucleation model, which reveals a change in the nucleation and growth mechanism from progressive to intermediate (progressive + instantaneous) to instantaneous with a rise in bath temperature (from 25 °C to 75 °C). The SEM study showed hexagonal grains for the films obtained at 35 °C. The x-ray diffraction spectra revealed the formation of phase-pure ZnO thin films. The chemical state of the deposit was confirmed by XPS measurements.