Abstract: Zinc oxide thin films with various microstructures
were grown on substrates by using HCOOH-sols. The reaction
mechanism of the sol system was investigated by performing an XPS
analysis of as-synthesized films, due to the products of hydrolysis
and condensation in the sol system contributing to the chemical state
of the as-synthesized films. The chemical structures of the assynthesized
films related to the microstructures of the final annealed
films were also studied. The results of the Zn 2p3/2, C 1s and O1s
XPS patterns indicate that the hydrolysis reaction in the sol system is
strongly influenced by the HCOOH agent. The results of XRD and
FE-SEM demonstrated the microstructures of the annealed films are
related to the content of hydrolyzed zinc hydrate (Zn-OH) species
present, and that content of the Zn-OH species in the sol system
increases the HCOOH adding, and these Zn-OH species existing in
the sol phase are responsible for large ZnO crystallites in the final
annealed films.