  The objective of this work was to investigate the photoelectrochemical (PEC)
performance of nanoparticulate hematite thin film photoelectrodes prepared by a
soft-chemistry route. Two cost-effective thin film fabrication techniques were
employed to deposit the hematite film. First, the film was deposited on
conducting glass substrates by dip coating of the organic precursor containing
fatty acid derivatives of iron salts. Process parameters such as the
concentration of iron oleic acid derivative precursor solution, the thickness
of the organic film, before annealing and the number of deposited layers along
with their weight and roughness were studied. In the second approach, the
influence of the spin coating process on film formation and respective
photoelectrochemical (PEC) performance have been discussed. It was found that
the PEC performance of spin-coated samples was lower than that of dip coated
samples due to the effect of films rough and smooth characteristics. It is
found that the rough surface of the photoelectrode is a prerequisite to
achieving good photocurrent values. Here, three-layer samples with roughness
between 600nm to 800nm and bulk thickness up to 700nm provided photocurrent
densities of 0.6mA/cm2. In part 2 of the manuscript, we have elaborately
discussed the roughness and smooth behavior of thin films using X-ray
reflectometry technique. Followed by this, a detailed account of the viscous
and thermal properties of the fatty acid derivatives of iron precursor have
been discussed.
