Abstract:
The semiconductor thin films of ZnO and CU2O were prepared by simple and low cost
techniques and characterized for determining the photogeneration of Hydrogen by splitting
water. Semiconductor thin film and a Cu plate were used as two electrodes in
photoelectrochemical cell and Fe2+/Fe3+ redox couple was used as the electrolyte.
ZnO thin films with different thicknesses have been prepared on cleaned glass substrates
by a spray pyrolysis technique using Zinc Hydroxide precursor at the temperature between
250 - 300 6C. Optical properties of the prepared ZnO thin films have been studied by using
UV-Visible spectroscopy and electrical resistance of thin film was measured. The
photocurrent densities of the ZnO thin film were carried out in a photoelectrochemical cell
under 60W light irradiation. Variations of absorbance, band gap, conductivity and
photocurrent density with film thickness were investigated. The effective optical band gap
and conductivity for ZnO thin films having film thickness ~2 pm were found to be 2.9 ev
and 1.9xl0'7 (ficm)' respectively. Significant amount of photocurrent was observed and
photocurrent density was found to be increased with film thickness. Higher photocurrent
density was observed film thickness with ~2 pm.
CU2O thin films have been prepared by heating Cu plates in air. The photoelectrochemical
properties of the prepared thin films were investigated as a function of Fe2+/Fe3+ redox
couple concentration. Time duration for decreasing photocurrent to dark current after
turning off light source was studied. 0.04 M Fe2+/Fe5+ redox couple concentration was
identified as optimum concentration of electrolyte in photoelectrochemical cell using CU2O thin film.
