title: Supramolecular n/p-heterojunction photosystems with antiparallel redox gradients in electron- and hole-transporting pathways.
abstract: Lessons from nature call for supramolecular n/p-heterojunctions with oriented multicolored antiparallel redox gradients (OMARG-SHJs) as "ideal" photosystems. Their design combines advantages of bilayer and bulk n/p-heterojunction (BHJ) solar cells for the directional separation of photogenerated charges before recombination can occur. Although conceptually attractive, OMARG-SHJs have remained beyond reach because of unresolved challenges in synthetic organic and supramolecular chemistry. Here we report the first OMARG-SHJs with two-component redox gradients in both the electron- and hole-transporting pathways. They were obtained by zipper assembly of stacks of red naphthalenediimide (NDI) electron donors along strings of oligophenylethynyl hole acceptors on top of yellow NDI electron acceptors along p-oligophenyl hole donors. The presence of both gradients is shown to be essential for achieving photoinduced charge separation over very long distances.
authors.affiliation: Department of Organic Chemistry, University of Geneva, 1211 Geneva 4, Switzerland.
authors.forename: Naomi
authors.initials: N
authors.lastname: Sakai
authors.forename: Rajesh
authors.initials: R
authors.lastname: Bhosale
authors.forename: Daniel
authors.initials: D
authors.lastname: Emery
authors.forename: Jiri
authors.initials: J
authors.lastname: Mareda
authors.forename: Stefan
authors.initials: S
authors.lastname: Matile