The development of outer-sphere electron mediators featuring low Femi-level brings forth a key advance of performance for dye-sensitized solar cells (DSCs).The judicious modulation of dye layer microstructure coated on the surface of titania to inhibit the interfacial charge recombination is one of the important research topics in the field based upon this rapid recombination device.In this paper

a high-absorptivity polypyridyl ruthenium sensitizer and a three-dimensional push-pull organic dye were employed to cosensitize the titania film.With respect to the cell involving pure ruthenium photosensitizer

the transient absorption spectrum measurements have disclosed that the employment of the three-dimensional organic dye can endow the cell with an improved efficiency of electron injection.Moreover

transient absorption and photovoltage decay measurements have revealed that this push-pull dye also confer the device with slower charge recombination of titania electrons with both photooxidized dye molecules and electron-donating species in electrolytes based upon the tris(1

10-phenanthroline)cobalt (Ⅱ/Ⅲ) redox couple

resulting in an evidently improved open-circuit voltage from 808 to 883 mV.Furthermore

the electron injection efficiency improvement and charge recombination diminishments through modulating the microstructure of interfacial photoactive layer can also overcompensate the adverse impact of reduced light-harvesting

bringing forth an enhanced photocurrent output observed in current-voltage measurements

and an overall power conversion efficiency improvement from 8.5% to 10.3% at the 100 mW cm-2

simulated AM1.5 conditions.