We will report systematic studies of the dye sensitization of metal oxide single crystal surfaces. Techniques for preparing atomically flat surfaces that reproducibly adsorb the carboxylated dye molecules were developed. Low index surfaces of both anatase and rutile were studied with adsorbed dicarboxylated cyanine dyes and the popular ruthenium based sensitizers. Photochronocoulometry was used to measure the surface coverage of the dye molecules in tandem with photocurrent spectroscopy. Photocurrent spectroscopy revealed the aggregation state of the dyes on the crystal surface. Adsorption isotherms for a series of structurally similar dyes were measured in order to speculate about the arrangement of the dye molecules on the various surfaces. Adsorption rates and desorption rates of the various dye molecules were studied and modeled with both analytical models and Monte Carlo simulations. It was found that the identity of the regenerator can have large influence on the desorption of carboxylate-bound dyes. Implications of these fundamental studies on the behavior of dye sensitized solar cells will be discussed.