Synthesis, Structural and Optical Study of ZNO Thin Films Prepared by Photo-Assisted Sol-Gel Method
ZnO thin films were prepared by UV photo-assisted sol-gel method using zinc acetate (Zn(CH 3 COO) 2 .2H 2 O) as
starting material , 2-methoxyethanol as solvent and monoethanolamine (MEA) as stabilizer. Thin films are deposited onto
glass substrates using dip-coating technique. After deposition and drying at 100°C, the ZnO thin films have been grown
using UV irradiation. The structural characterization of films has been performed using X-ray diffraction which shows the
formation and the progressive growth along direction  of ZnO crystallites with hexagonal structure. The FTIR spectrum
reveals the presence of a peak situated at 418 cm -1 corresponding to the Zn-O stretching which confirms the ZnO formation.
The optical absorption of the ZnO thin films shows a shift of the gap to higher energies. The shoulder observed on the
optical absorption spectrum indicates a large size dispersion of ZnO crystallites. The photoluminescence spectrum at room
temperature reveals an intense and a wide band in the visible region from 400 to 800nm. The photoluminescence emission is
formed of six bands which can be associated with various defects in ZnO crystallites.
Keywords : ZnO, Photo-assisted sol-gel method, XRD, IR spectroscopy, UV-Visible absorption, Photoluminescence.