Low-cost Photoactive Hybrid Materials: From Green Synthesis to Multi-technique Analytical Characterization

Low-cost photoactive hybrid materials for light management, based on neutral organic molecules intercalated into saponite, were prepared by facile green methods and characterized. TPBI (2-(2'-tosylaminophenyl)benzimidazole) was chosen as an organic host dye, envisioning its application as a downconverter in silicon or dye-sensitized photovoltaic modules. Mixed with a cationic surfactant, the neutral molecule was intercalated with a sort of "trojan horse" approach by an easy, almost solvent-free method, thus limiting its aggregation. The obtained material was characterized by combining spectroscopic, diffractometric, and microscopic techniques. Moreover, the intercalation of the dye, the species present in the interlayer, their stability and mutual interactions were assessed by TGA-GC-MS. We obtained a material containing a fluorescent dye in the solid state and stabilized by intercalation and dispersion into saponite. At last, this material was used to prepare a photoactive polymer by melt blending, obtaining materials with the desired optical properties, with Stokes shifts larger than 100 nm and an emission yield above 50%.