The effect of electrochemical deposition duration and the heat treatment at 450 °С within 1 hour
on the microstructure of ZnO thin films, including their phase composition, lattice parameters,
microstrain, grain size and surface morphology is investigated. The empirical relationships
allowing to predict the molar composition and the ZnO/FTO thickness ratio depending on the
specific charge passing through the substrate during the film formation process have been
obtained. According to scanning electron microscopy, there is a consolidation of the film
crystallites after the heat treatment leading to formation of hexagonal nanorods. An average size
of the crystallites before the heat treatment is 0.727 μm, and after the heat treatment it is
0.455 μ