Two different amines as complexing agents were used in a two-step sol-gel method to prepare TiO2 nanoparticles. The effect of amines on the size of the TiO2 nanocrystals and its influence on the performance of corresponding dye-sensitized solar cell (DSSC) were investigated. It is shown that using a tertiary long chained monoamine as a complexing agent is beneficial in two ways; one is producing the particles with smaller size and the other is slightly sticking the particles in order to have a film with higher reflectivity which both is beneficial to photovoltaic performance. The obtained products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectra, and ultraviolet-visible (UV-vis) spectroscopy. The overall conversion efficiency of the long-chain-based DSSC (5.04%) appeared to be 45% higher than that obtained for the tertiary short-chain diamine. (c) 2013 Elsevier Ltd. All rights reserved.