Colloidal p-CuI-sensitized double-dye system

Colloidal p-CuI deposited on copper substrates is sensitized with a double- dye system, rhodamine iodide and crystal violet. Rhodamine iodide is deposi ted on colloidal p-CuI as the first dye before the second dye crystal viole t is deposited on rhodamine iodide. A photocurrent quantum efficiency enhan cement can be observed for the double-dye system in comparison with the bar e dye-sensitized systems. Two peaks can be clearly observed in the photocur rent action spectrum of the double-dye system. Absorption spectra, fluoresc ence spectra, photocurrent action spectra and energy level diagrams are pre sented in order to explain the possible reasons for the photocurrent genera tion mechanisms of the two peaks (approximate to 530 nm and approximate to 620 nm) in the double-dye photocurrent action spectrum.