LAUSR

ABSTRACT Zinc and copper ions were incorporated on the surface of TiO2 films via a dipping process, and the resulting films were used as the photoelectrodes of dye-sensitized solar cells (DSSCs). The DSSC with Zn2+(30)-TiO2/FTO electrode, prepared by soaking bare TiO2/FTO in a zinc nitrate solution for 30 min, showed an improvement in power conversion efficiency, due to an enhancement in both open circuit voltage (Voc) and short circuit current (Jsc), compared to those of reference cell with bare TiO2/FTO. It was revealed that the Zn2+ incorporation on the TiO2 surface led to a retardation of the back electron transfer, inducing a prolonged electron lifetime of photo-injected electrons, and thereby increasing the Voc and Jsc. On the contrary, the back electron transfer was scarcely delayed in the device with Zn2+(30)-TiO2/FTO electrode.