Solid-state and liquid-junction photovoltaic properties of some polar dyes

Abstract

A number of solid-state Schottky barrier cells of the type Al/Al₂O₃/merocyanine, I₂/Au and liquid-junction cells of the type metal/merocyanine/redox electrolyte/Pt have been prepared. Their photovlotaic behaviour depends strongly on the ionisation potential of the merocyanine dye. Doping the dye is crucial to the generation of efficient cells. Iodine dopant is particularly effective and ambient air rather less so, because the films absorb greater concentrations of iodine. The results are in qualitative agreement with a model based on exciton dissociation at dopant sites in the space-charge region of a Schottky barrier formed at a dye/metal or dye/redox-couple interface.