QCM-2015-1-0022 Analysis of the ultrafast charge transfer in organic photovoltaic devices based on endohedral metallofullerenes:

Fullerenes and carbon nanotubes show interesting physicochemical properties, which render them very promising for a wide range of applications. Endohedral metallofullerenes (EMFs), which are carbon cages that encapsulate metal atoms or clusters, have attracted increasing attention due to their new properties and potential relevance in the fields of biomedicine and nanomaterials sciences.What renders EMFs particularly appealing is that the chemical and physical properties can be tuned by changing the nature and composition of the internal species. In 1999, Dorn and co-workers
reported the characterization of Sc3N@Ih(7)-C80, which is the most abundant fullerene after C60 and C70 and the prototype of the family of trimetallic nitride EMFs. Nitride EMFs are good candidates to replace C60 or C70 as optimal electron acceptors in fullerene-based solar cells since they feature, compared to C60, larger absorption coefficients in the visible region of the electromagnetic spectrum and an outstanding ability to stabilize charge-separated states, while
preserving a remarkable electron accepting ability. Actually, the polymeric solar cell based on the P3HT polymer donor and the Lu3N@C80-PCBH acceptor shows a higher overall power conversion efficiency compared to the P3HT/C60-PCBM device.[3] Moreover, the donor-acceptor dyad made by ferrocene as electron donor and Sc3N@C80 as electron acceptor, in which the two units are covalently linked through a pyrrolidine ring, shows longer lifetimes for the radical ion pair state than the analogous C60-ferrocene conjugate.