Electron paramagnetic resonance studies of dye-sensitized zinc oxide layers

EPR studies of dye-sensitized zinc oxide layers constitute a valuable source of information, particularly when combined with other types of photoelectronic measurements. The EPR action spectrum, at 77 K, of zinc oxide sensitized with rose bengal correlates well with the dye absorption spectrum and the room temperature photoconductivity action spectrum. Studies of the kinetics of the rise of the g = 1.96 signal on illumination as a function of oxygen pressure indicate the existence of two mechanisms for deriving the paramagnetic species.