title: Evidence of harvesting electricity by exciton recombination in an n-n type solar cell.
abstract: Free electrons and holes bounded by weak interactions in organic molecules must be generated from excitons to produce photocurrent in organic solar cells. Free charge carriers, in either small molecule- or polymer-based solar cells, are generated so far by dissociation of excitons at the donor-acceptor interface through injecting electrons (holes) from a donor (acceptor) into an acceptor (donor) while leaving holes (electrons) in the donor (acceptor). Here we report a new way, intermolecular exciton recombination, to generate free carriers from organic semiconductors. Unlike the exciton dissociation between donor and acceptor, the recombination of electrons from perfluorinated hexadecafluorophthalo-cyaninatozinc (F16ZnPc) with holes from fullerene (C(60)) frees their counterpart carriers. A new organic solar cell based on this intermolecular exciton recombination at the interface is fabricated to clearly demonstrate this new way to produce free carriers and then harvest electricity from sunlight.
authors.affiliation: School of Chemical & Biomedical Engineering & Centre for Advanced Bionanosystems, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457.
authors.forename: Qun Liang
authors.initials: QL
authors.lastname: Song
authors.forename: Hong Bin
authors.initials: HB
authors.lastname: Yang
authors.forename: Ye
authors.initials: Y
authors.lastname: Gan
authors.forename: Cheng
authors.initials: C
authors.lastname: Gong
authors.forename: Chang
authors.initials: C
authors.lastname: Ming Li
mesh_terms: D004560:Electricity; D037741:Fullerenes / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D012993:Solar Energy; D015032:Zinc / Q000737:chemistry*
chemical_list: D037741:Fullerenes; D009942:Organometallic Compounds; D015032:Zinc; C069837:fullerene C60