We report the preparation of conformational coatings of the titania electrode by trifluoroacetic acid (TFA) and its influence on the efficiency of dye sensitised solar cells. We have observed that the TFA creates a hydrophobic barrier on the titania surface preventing direct contact with the electrolyte. Interestingly, when N719 is used as sensitiser, the presence of TFA accelerates the recombination reactions between photo-injected electrons at the TiO₂ and the oxidised electrolyte.