The Driving Force of Photoinduced Charge Separation in Metal-Cluster-Encapsulated Triphenylamine-[80]fullerenes.

Understanding photoinduced charge separation in fullerene-based dye-sensitized solar cells is crucial for the development of photovoltaic devices. We investigate here how the driving force of the charge separation process in conjugates of M@C80 (M=Sc3 N, Sc3 CH, Sc3 NC, Sc4 O2 , and Sc4 O3 ) with triphenylamine (TPA) depends on the nature of the metal cluster. Both singlet and triplet excited-state electron-transfer reactions are considered. These results based on TD-DFT calculations demonstrate that the driving force of charge separation in TPA-M@C80 can be tuned well by varying the structure of the metal cluster encapsulated inside the fullerene cage.