Porosity values between 0.12 and 0.40 are achieved in a controllable way for TiO2 electrodes in dye-sensitized solar cells by irradiation with a pulsed Nd:YAG laser at 1064 nm. Whereas the electron lifetime and diffusion distance increase with reduced porosity, the amount of adsorbed dyes remains almost constant. This greatly enhances the photocurrent density and energy conversion efficiency of the solar cell.