TiO2 nanoparticle aggregations prepared by nitro-functionalized tripodal ligand as promising candidates for dye-sensitized solar cells

Tripodal tetraamine ligands were nominated as complexing agent in preparation of TiO2 nanoparticle via a two-step sol–gel method. The effect of complexing agents was investigated on the particle and aggregation size as well as optical and photovoltaic properties. The products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron spectroscopy (TEM), scanning electron microscopy (SEM), and UV–vis spectroscopy. The results showed that the symmetry of ligands has a crucial effect on the size of the particles and the aggregations. Three different tripodal ligands were applied as complexing agents. Larger aggregation size with tiny nanoparticles was obtained from the sample prepared with Nitro-funtionalized ligand and led to improved photovoltaic performance due to enhanced photon scattering in the sample.