Molecular Model of Dye Sensitized Titanium Oxides Based on Aryl-Amine Dye Anchored Titanium Oxo Clusters

Model studies on dye sensitized titanium oxides have attracted wide interest with respect to their importance in understanding photoelectric and photophysical processes. Ligand modified titanium oxo clusters (TOCs) have been considered as the most appropriate models for dye sensitized solar cells (DSSCs) on the basis of their atomically precise structures. However, the ligands used previously in TOC models were seldom the dyes that really applied in DSSCs due to the difficulty with which the crystals of the dye anchored TOCs are obtained. We report herein a series of TOCs with the popularly used arylamine-cyanoacrylate dyes. As the closest model of DSSCs, the TOCs were studied by DFT calculations based on their accurate structural information. They have also been applied to photoelectric conversion evaluation by a solar cell device. Both the theoretical and application results showed that the synergistic effect of intradye molecular charge transfer (ICT) and dye to TiO cluster charge transfer (LMCT) is important in increasing the power conversion efficiency.