Photovoltaic charge generation in organic semiconductors based on long-range energy transfer.

摘要: For efficient charge generation in organic solar cells, photogenerated excitons must migrate to a donor/acceptor interface where they can be dissociated. This migration is traditionally presumed based on diffusion through the absorber material. Herein we study an alternative route—two-step exciton dissociation—whereby jumps from donor acceptor before creation takes place. We this process series of multilayer donor/barrier/acceptor samples, either poly(3-hexylthiophene) (P3HT) or copper phthalocyanine (CuPc) donor, fullerene (C60) acceptor, and N,N-diphenyl-N,N-bis(3-methylphenyl)-[1,1-bisphenyl]-4,4-diamine (TPD) acts as barrier energy transfer. By varying thickness layer, find that transfer P3HT C60 proceeds over large distances (∼50% probability across 11 nm barrier), consistent with long-range Forster resonance (FRET). Finally, demo...