The suppression of the recombination of photogenerated carriers in a dye-sensitized nano-porous solid-state photovoltaic cell

The p-n junction p-Cul/nano-porous n-TiO2 made by coating Cul on a nano-porous film of n-TiO2 does not show a photocurrent action spectrum corresponding to the bandgap excitation of TiO2. However, if the surface is lightly coated with the dye cyanidin the peak corresponding to bandgap excitation of TiO2 is clearly manifested in addition to the sensitization peak. The effect is explained as originating from the relay action of the dye molecules adsorbed at the surface of TiO2 mediating hole transfer from the valence band of TiO2 to the valence band of p-Cul.