title: Molecular packing and solar cell performance in blends of polymers with a bisadduct fullerene.
abstract: We compare the solar cell performance of several polymers with the conventional electron acceptor phenyl-C61-butyric acid methyl ester (PCBM) to fullerenes with one to three indene adducts. We find that the multiadduct fullerenes with lower electron affinity improve the efficiency of the solar cells only when they do not intercalate between the polymer side chains. When they intercalate between the side chains, the multiadduct fullerenes substantially reduce solar cell photocurrent. We use X-ray diffraction to determine how the fullerenes are arranged within crystals of poly-(2,5-bis(3-tetradecylthiophen-2-yl)thieno[3,2-b]thiophene) (PBTTT) and suggest that poor electron transport in the molecularly mixed domains may account for the reduced solar cell performance of blends with fullerene intercalation.
authors.affiliation: Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA.
authors.forename: Nichole
authors.initials: N
authors.lastname: Cates
authors.forename: Sean
authors.initials: S
authors.lastname: Sweetnam
authors.forename: Eric T
authors.initials: ET
authors.lastname: Hoke
authors.forename: Roman
authors.initials: R
authors.lastname: Gysel
authors.forename: Chad E
authors.initials: CE
authors.lastname: Miller
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Bartelt
authors.forename: Xinxin
authors.initials: X
authors.lastname: Xie
authors.forename: Michael F
authors.initials: MF
authors.lastname: Toney
authors.forename: Michael D
authors.initials: MD
authors.lastname: McGehee
mesh_terms: D011211:Electric Power Supplies; D004735:Energy Transfer; D004867:Equipment Design; D019544:Equipment Failure Analysis; D037741:Fullerenes / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D012993:Solar Energy
chemical_list: D037741:Fullerenes; D011108:Polymers