title: An electron-deficient small molecule accessible from sustainable synthesis and building blocks for use as a fullerene alternative in organic photovoltaics.
abstract: An electron-deficient small molecule accessible from sustainable isoindigo and phthalimide building blocks was synthesized via optimized synthetic procedures that incorporate microwave-assisted synthesis and a heterogeneous catalyst for Suzuki coupling, and direct heteroarylation carbon-carbon bond forming reactions. The material was designed as a non-fullerene acceptor with the help of DFT calculations and characterized by optical, electronic, and thermal analysis. Further investigation of the material revealed a differing solid-state morphology with the use of three well-known processing conditions: thermal annealing, solvent vapor annealing and small volume fractions of 1,8-diiodooctane (DIO) additive. These unique morphologies persist in the active layer blends and have demonstrated a distinct influence on device performance. Organic photovoltaic-bulk heterojunction (OPV-BHJ) devices show an inherently high open circuit voltage (Voc ) with the best power conversion efficiency (PCE) cells reaching 1.0 V with 0.4 v/v % DIO as a processing additive.
authors.affiliation: Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, NS, B3H 4R2 (Canada).
authors.forename: Seth M
authors.initials: SM
authors.lastname: McAfee
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Topple
authors.forename: Abby-Jo
authors.initials: AJ
authors.lastname: Payne
authors.forename: Jon-Paul
authors.initials: JP
authors.lastname: Sun
authors.forename: Ian G
authors.initials: IG
authors.lastname: Hill
authors.forename: Gregory C
authors.initials: GC
authors.lastname: Welch
keywords: electron acceptors; isoindigo; microwave-assisted synthesis; organic solar cells; solution-processed small molecules