In the literature, a comprehensive assessment of the combined impacts
of chemical and mechanical parameters on the properties of thin films grown by SILAR
is missing. In this work, ZnO film formation is investigated under variable precursor
concentration, pH, withdrawal speed and number of cycles. Interestingly, the produced
ZnO films displayed remarkable aspect ratio and morphological variability, ranging
from the commonly obtained nanograins shape towards hexagonal nanorods, flower-
like rods and nanoneedles, which to our knowledge have not yet been achieved by using
single step SILAR process. More particularly, low concentration and intermediate pH
and withdrawal rates were favorable for nanorods formation. In addition, increasing the
withdrawal speed from 26 to 30 cm·min-1 resulted in a thinner film with improved rod
uniformity and reduced crystallite size. This is the first study on the impact of substrate
withdrawal speed on SILAR films. Among all studied parameters, the number of cycles
was particularly useful for tuning film thickness, while preserving its target shape. In
addition, the films grown under a higher number of cycles showed improved film
crystallinity and rod orientation with reduced dislocation density, microstrain and
bandgap energy. In our conditions, the most suitable combination of parameters required
for exhibiting optimized nanorod-shaped coating are: a concentration of 0.07 M, pH of
10.5, speed of 30 cm·min-1 and 40 cycles. In this case, XRD, XPS, Raman and FTIR
spectra displayed typical features of hexagonal Wurtzite structure of ZnO with no
impurities within the film surface, whereas AFM measured a thickness of 1.4 μm with
243 nm surface roughness.