The successful fabrication of efficient dye-sensitized solar cells containing electrophoretically-deposited mesoporphyrin IX in semiconductor films based on sintered TiO2 nanoparticles is presented in this work. For comparison purposes, photocells utilizing mesoporphyrin IX-sensitized TiO2 electrodes were also constructed following the traditional dip-coating deposition technique. Electrochemical responses obtained from these modified surfaces revealed that the electrophoretic methodology generated perpendicularly-arranged porphyrin layers on the sintered oxide nanoparticles, while the dip-coating deposition technique resulted in parallel layers of porphyrin. It was demonstrated that the photovoltaic performance of cells containing electrophoretically-dyed TiO2 films was three times higher than that of devices having photoelectrodes constructed according to the dip-coating protocol. To better understand this behavior, both types of solar cells were further investigated by means of photoelectrochemical impedance spectroscopy. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3570990] All rights reserved.