title: Mesoscale molecular network formation in amorphous organic materials.
abstract: High-performance solution-processed organic semiconductors maintain macroscopic functionality even in the presence of microscopic disorder. Here we show that the functional robustness of certain organic materials arises from the ability of molecules to create connected mesoscopic electrical networks, even in the absence of periodic order. The hierarchical network structures of two families of important organic photovoltaic acceptors, functionalized fullerenes and perylene diimides, are analyzed using a newly developed graph methodology. The results establish a connection between network robustness and molecular topology, and also demonstrate that solubilizing moieties play a large role in disrupting the molecular networks responsible for charge transport. A clear link is established between the success of mono and bis functionalized fullerene acceptors in organic photovoltaics and their ability to construct mesoscopically connected electrical networks over length scales of 10 nm.
authors: Department of Chemistry, Northwestern University, Evanston, IL 60208; and brettsavoie@u.northwestern.edu t-marks@northwestern.edu ratner@northwestern.edu.
authors: Brett M
authors: BM
authors: Savoie
authors: Department of Chemistry, Northwestern University, Evanston, IL 60208; and.
authors: Kevin L
authors: KL
authors: Kohlstedt
authors: Department of Chemistry, Northwestern University, Evanston, IL 60208; and.
authors: Nicholas E
authors: NE
authors: Jackson
authors: Department of Chemistry, Northwestern University, Evanston, IL 60208; andChemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, 60439.
authors: Lin X
authors: LX
authors: Chen
authors: Department of Chemistry, Northwestern University, Evanston, IL 60208; and.
authors: Monica
authors: M
authors: Olvera de la Cruz
authors: Department of Chemistry, Northwestern University, Evanston, IL 60208; and.
authors: George C
authors: GC
authors: Schatz
authors: Department of Chemistry, Northwestern University, Evanston, IL 60208; and brettsavoie@u.northwestern.edu t-marks@northwestern.edu ratner@northwestern.edu.
authors: Tobin J
authors: TJ
authors: Marks
authors: Department of Chemistry, Northwestern University, Evanston, IL 60208; and brettsavoie@u.northwestern.edu t-marks@northwestern.edu ratner@northwestern.edu.
authors: Mark A
authors: MA
authors: Ratner
keywords: charge generation; disordered properties; soft materials