Formation of Semiconducting Supramolecular Fullerene Aggregates in a Dipeptide Organogel.

The formation of nanostructured fullerene aggregate inside supramolecular gels is a topic of great interest because of the potential applications of these nanostructures in photoelectronics. Gel phase facilitates the aggregation of fullerene by restricting the movement of solvent molecules, thereby increasing the local fullerene concentration. Herein, the supramolecular nanostructure formation of fullerene (C) in a minimalistic dipeptide (diphenylalanine, FF) organogel is reported. The resulting composite FF/Fullerene gels exhibit improved mechanical properties and semiconductivity. While fullerene nanostructures do not disturb the FF aggregation pattern, they adhere to the FF fibers via non-covalent interaction. Morphological analysis reveals the presence of spherical clusters and nanorods of fullerene attached to the dipeptide fibers. The composite gel with highest fullerene concentration exhibits linear current-voltage response with a current magnitude of ≈0.3 nA. Moreover, poly(3,4- ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is incorporated in the FF/Fullerene system yielding tri-hybrid donor-acceptor gels which exhibit photoresponsive conductivity. Therefore, the FF/Fullerene and the tri-hybrid gel have interesting properties, and holds significant promise toward photoelectronic device applications.