Dye-sensitized solar cells (DSSCs) are composed of an electrode made of a dye-adsorbed nanoporous TiO2 layer on a fluorine-doped tin oxide (FTO) glass substrate, redox electrolytes, and a counter electrode. In this study, phosphor is introduced into the TiO2-layer electrode of a DSSC. The admixed phosphor content in the TiO2 paste is varied from 1.0 to 10.0wt%. By a conversion-luminescence process, ZnGa2O4:Mn2+ phosphor improves light harvesting and increases the photocurrent. The phosphor elevates both, the energy level of electrons in the oxide film and V-oc of the DSSC. Using a TiO2 electrode containing 5.00wt% of admixed ZnGa2O4:Mn2+, the light-to-electricity energy-conversion efficiency of the DSSC reaches 8.02%, which is higher by a factor of 1.25 than that of a DSSC without ZnGa2O4:Mn2+.