In this research P25 TiO2 nanoparticles (NPs) and hydrothermally grown TiO2 nanocrystals (NCs) were used in the photoanode of the dye sensitized solar cells. The dominant size of hydrothermally grown TiO2 NCs was about 20 nm. Different photoanode compositions including various weight percents of different NCs were prepared. The photoelectrodes demonstrated a light scattering which was strongly dependent on the weight percent of P25 TiO2 NPs. According to the results, when the photoanode was dominantly composed of hydrothermally grown TiO2NCs, the dye sensitized solar cells represented acceptable efficiencies. For the weight percent ratios of 70/30 and 30/70 for hydrothermally grown to P25 TiO2 NPs the efficiency was considerably decreased. This was specially observed for the thicker photoelectrodes. Nevertheless, when the photoanode was composed of equal weight percents of different NCs (50/50), the maximum efficiency of 7.1% was achieved. This was addressed due to the optimum situation of light scattering, dye adsorption and minimum of the tension in photoanode layer.
