title: Broadening the absorption of conjugated polymers by "click" functionalization with phthalocyanines.
abstract: Conjugated copolymer derivatives of poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and poly(3-hexylthiophene) (P3HT) containing 10% of alkyne functionalities in the side chains have been prepared using the sulfinyl precursor route and the Rieke method, respectively. With the aim of expanding the absorption range of these conjugated polymers for their use in bulk heterojunction (BHJ) polymer:fullerene solar cells, appropriate phthalocyanine (Pc) molecules have been covalently bound through a post-polymerization "click chemistry" reaction between the alkyne functionalities in the side chains of the copolymers and a Pc functionalized with an azide moiety. The resulting poly(p-phenylenevinylene)-Pc (PPV-Pc) material holds a 9 mol% content of Pcs, while the polythiophene-Pc material (PT-Pc) contains a 8 mol% of Pc-functionalization in the side chains. As expected, the presence of the Pc contributes to the extension of the absorption up to 700 nm. BHJ solar cells have been prepared using PPV-Pc and PT-Pc materials in combination with PCBM. Although the Pc absorption contributes to the generation of photocurrent, the overall power conversion efficiencies (PCE) obtained from these cells are lower than those obtained with BHJ P3HT:PCBM (1:1) and MDMO-PPV:PCBM (1:4) solar cells. A plausible explanation could be the moderate solubility of the PPV-Pc and PT-Pc materials that limits the processing into thin films.
authors.affiliation: Hasselt University, Campus Diepenbeek Institute for Materials Research Agoralaan Building D, 3590, Diepenbeek, Belgium.
authors.forename: Bert J
authors.initials: BJ
authors.lastname: Campo
authors.forename: Jan
authors.initials: J
authors.lastname: Duchateau
authors.forename: Carolina R
authors.initials: CR
authors.lastname: Ganivet
authors.forename: Beatriz
authors.initials: B
authors.lastname: Ballesteros
authors.forename: Jan
authors.initials: J
authors.lastname: Gilot
authors.forename: Martijn M
authors.initials: MM
authors.lastname: Wienk
authors.forename: Wibren D
authors.initials: WD
authors.lastname: Oosterbaan
authors.forename: Laurence
authors.initials: L
authors.lastname: Lutsen
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Cleij
authors.forename: Gema
authors.initials: G
authors.lastname: de la Torre
authors.forename: René A J
authors.initials: RA
authors.lastname: Janssen
authors.forename: Dirk
authors.initials: D
authors.lastname: Vanderzande
authors.forename: Tomás
authors.initials: T
authors.lastname: Torres