title: Investigation of cation-induced degradation of dye-sensitized solar cells for a new strategy to long-term stability.
abstract: Current-voltage characteristics, electron lifetimes (tau), and electron diffusion coefficients (D) of dye-sensitized TiO2 solar cells (DSCs) composed of liquid electrolytes were repeatedly measured over a period of time. It was found that the energy conversion efficiency of the DSCs using electrolytes composed of Li+ or tetrabutylammonium cation as the counter charges of I-/I3- redox couples decreased with the lapse of time. On the other hand, such a decrease was not observed for the DSC consisting of 1,2-dimethyl-3-propylimidazolium cation or of Li+ coupled with the addition of tert-butylpyridine. The decrease of the efficiency was in accordance with a decreased electron lifetime. The notable decrease in the presence of Li+ is probably caused by the excess amount of Li+ adsorption on the TiO2 surface.
authors.affiliation: Material and Life Science, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Shogo
authors.initials: S
authors.lastname: Nakade
authors.forename: Taisuke
authors.initials: T
authors.lastname: Kanzaki
authors.forename: Shingo
authors.initials: S
authors.lastname: Kambe
authors.forename: Yuji
authors.initials: Y
authors.lastname: Wada
authors.forename: Shozo
authors.initials: S
authors.lastname: Yanagida