Hikmat S. Hilal1*, Rania M. A. Ismail2, and Amer El-Hamouz3, Ahed Zyoud1, Iyad Saadeddin4

1Department of Chemistry, 2Clean Energy and Conservation Energy Study Program, 3Department of Chemical Engineering, 4Department of Physics

An-Najah N. University, PO Box 7, Nablus, West Bank, Palestine

Fax: 00970-9-2387982

*Corresponding author: [email protected]

Abstract

Thin films of CdS, deposited by Chemical Bath Deposition (CBD) onto films of fluorine-doped tin oxide/glass (glass/FTO) substrates were prepared and investigated for photo-electrochemical (PEC) conversion of light into electricity.  Knowing the hazardous nature of CdS, the focal theme of this work was to modify the electrodes by simple economic ways to maximize their conversion efficiency and minimize their degradation under PEC conditions. This was to avoid leaching out of hazardous Cd2+ ions. Different parameters have been investigated for this purpose.  Multi-deposition preparation, redox couple, and electrode etching affected electrode PEC characteristics. Consistent with earlier literature, annealing the electrode enhanced its conversion efficiency and stability. On the other hand, effect of cooling rate of pre-annealed CdS electrodes, prepared by CBD, on their PEC characteristics has been investigated here for the first time. Controlling the cooling rate was one major factor that affected CdS surface morphology, conversion efficiency and stability under PEC conditions.  The major recommendation coming out here is that PEC characteristics of CdS thin film electrodes can be significantly enhanced by pre-annealing the electrode at ~250oC followed by its slow cooling.

Electrochimica Acta
Article in Press, Accepted Manuscript, 2009