Photosensitization of the charge transfer across ZnO interfaces by binary dye mixtures

Abstract

The mutual influence of Orange II and Rhodamine B on their sensitizing ability for the electron transfer across the interface ZnO/adsorbed species has been studied by and electrochemical cell technique. Besides voltage against current measurements the absorption and fluorescence of the dyes were also determined. It was demonstrated that despite the similarity of the quenching of the fluorescence of Rhodamine B both by Orange II and halide ions, they do not follow a similar mechanism. Furthermore, the complexity of the mechanism of the sensitization by binary dye mixtures has been shown by photocurrent measurements in the presence of Morin and Rhodamine B, and Morin and an azo dye, at various pH of the electrolytes.