Controlling Adsorption Structure of Eosin Y Dye on Nanocrystalline TiO2 Films for Improved Photovoltaic Performances

Adsorption structure of Eosin Y dyes on nanocrystal-line TiO2 can be manipulated by adding a small fraction of water into organic electrolyte. Binding mode switching from hydrogen bonded monodentate to bidentate bridging configuration has been observed and confirmed by Raman and infrared spectroscopy measurements, with vibration peaks assigned using density functional theory calculations. Photovoltaic measurements on the fabricated dye-sensitized solar cells indicate that energy conversion efficiency is enhanced by manipulating molecular adsorption configuration of Eosin Y dyes. This opens a new avenue to improving photovoltaic performance by suppressing unfavorable adsorption configurations in dye solar cell devices.