PHOTOELECTROCHEMICAL STUDIES OF SPRAYED THIN-FILM N-ZNO ACETONITRILE BASED PHOTOCELL SENSITIZED BY RHODAMINE-B/

Photoelectrochemical cell based on thin film ZnO electrode sensitized by rhodamine B (Rh B) has been studied in acetonitrile medium using hy droquinone as supersensitizer. Redox potentials of Rh B determined cyc lic voltammetrically at Pt electrode in acetonitrile, coupled with the flat-band potential of ZnO electrode (obtained from Mott-Schottky plo t) have been used to determine their respective energy levels. Stable photovoltage was found to be -260 mV. Quantum efficiency of the sensit ized photocurrent at 550 nm wavelength of monochromatic light was foun d to be 6.5%, the highest ever reported for pure ZnO electrode sensiti zed by Rh B. Long-term stability of ZnO electrode in the medium of inv estigation has been tested and quite encouraging results have been obt ained.