Retardation of electron injection at NiO/dye/electrolyte interface by aluminium alkoxide treatment

Abstract

In order to retard geminate recombination in dye sensitized p-type NiO solar cells, surface treatment by aluminium alkoxide to form a thin insulating layer was applied. Open circuit voltage, short circuit current density, and energy conversion efficiency of the cell were increased by the treatment. The incident photon to current conversion efficiency (IPCE) of the light absorption wavelength of sensitizer was increased by 40% while that at the wavelength of direct excitation of NiO was reduced. The result suggests the electron injection of surface adsorbed dye was reduced more than the desired hole injection from the dye.